TWI834615B - Method for non-contact measuring of an on-body and/or inside-body motion of an individual and system for measuring motion of an individual - Google Patents
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Abstract
Description
本發明係關於運動之偵測，且特定言之，在無需實體接觸之情況下偵測生命徵象。 The present invention relates to the detection of motion and, in particular, the detection of vital signs without the need for physical contact.
生命徵象之監測(諸如例如心率、血壓、呼吸率及呼吸運作)係用於患者管理及病理記錄之一關鍵程序。基於身體電極、光學吸收、壓力或應變計及超音波或射頻(RF)反向散射之當前實踐具有對感測能力及取樣率之各自限制。量測程序亦可歸因於直接皮膚接觸或運動約束而使受測試個體不舒適或破壞個體之晝夜節律。此不便顯著增加護理者之工作負載且阻礙連續長期監測。 Monitoring of vital signs (such as, for example, heart rate, blood pressure, respiratory rate and respiratory performance) is a critical procedure for patient management and pathology documentation. Current practices based on body electrodes, optical absorption, pressure or strain gauges, and ultrasound or radio frequency (RF) backscatter have respective limitations on sensing capabilities and sampling rates. Measurement procedures may also cause discomfort to the subject being tested or disrupt the individual's circadian rhythm due to direct skin contact or movement restrictions. This inconvenience significantly increases caregiver workload and prevents continuous long-term monitoring.
歸因於身體表面之強反射及所反射信號之幾何平均值，用於基於射頻(「RF」)之遠場生命徵象偵測之習知技術可容易地揀取呼吸運動，但此等技術難以區分小機械振動細節，諸如具有低RF頻率之心跳及腕部脈搏波形。儘管可在仔細濾波之後擷取心率，但血壓之估計及多個自由移動之人的同時監測仍無法實現。 Conventional techniques for radio frequency (“RF”)-based far-field vital sign detection can easily pick up breathing movements due to strong reflections from the body surface and the geometric mean of the reflected signals, but these techniques are difficult to Distinguish small mechanical vibration details such as heartbeats and wrist pulse waveforms with low RF frequencies. Although heart rate can be acquired after careful filtering, blood pressure estimation and simultaneous monitoring of multiple freely moving people are still not possible.
仍長久企盼用於偵測生命徵象之低侵入式技術。 Less invasive technologies for detecting vital signs remain long awaited.
本發明提供一種RF近場同調感測(NCS)而無需直接皮膚接觸之方法。本發明方法可用於將身體上及/或其內部之即時機械運動直接調變至一多工無線電上，該多工無線電可含有一唯一識別(ID)。本文中描述兩項例示性實施例以提供部署及操作之靈活性：心臟及腕部附近之被動標籤及主動標籤。為減少部署及維護成本，被動RFID標籤可整合至胸部及腕部區域處之服裝中，其中可在讀取器處收集兩個多工遠場反向散射波形以擷取心率、呼吸率、呼吸運作(breath effort)及血壓。為改良讀取範圍及對室內運動之免疫力，主動標籤可放置於例如一前部口袋及一腕部袖口中以量測歸因於NCS之天線反射，且接著完全以數位格式取樣及傳輸生命信號以消除室內多路徑干擾。本發明揭示之生命徵象監測系統可同時用於多個個體，且可帶來護理設施中之成本效益自動化。此外，直接皮膚接觸及運動約束之消除將增強患者舒適性，此可實現改良病理分析之長期監測。 The present invention provides a method of RF near-field coherent sensing (NCS) without direct skin contact. The method of the present invention can be used to modulate real-time mechanical movements on the body and/or within it directly to a multiplex radio, which may contain a unique identification (ID). Two illustrative embodiments are described herein to provide flexibility in deployment and operation: passive tags near the heart and wrist and active tags. To reduce deployment and maintenance costs, passive RFID tags can be integrated into clothing at the chest and wrist areas, where two multiplexed far-field backscatter waveforms can be collected at the reader to capture heart rate, respiration rate, respiration Breath effort and blood pressure. To improve read range and immunity to indoor motion, active tags can be placed in, for example, a front pocket and a wrist cuff to measure antenna reflections due to NCS, and then sample and transmit life entirely in a digital format signal to eliminate indoor multipath interference. The disclosed vital sign monitoring system can be used with multiple individuals simultaneously and can lead to cost-effective automation in nursing facilities. In addition, the elimination of direct skin contact and movement constraints will enhance patient comfort, which allows for improved long-term monitoring of pathological analysis.
透過使用用於生命徵象監測之一例示性諧波RFID系統之NCS之一實施方案，可監測呼吸、心跳及腕部脈搏以導出呼吸率、心率及血壓。在一些實施例中，可將頻譜等化應用至NCS信號以復原時域中之精確心跳時間間隔。 Through an implementation of the NCS using an exemplary harmonic RFID system for vital sign monitoring, respiration, heartbeat, and wrist pulse can be monitored to derive respiration rate, heart rate, and blood pressure. In some embodiments, spectral equalization can be applied to the NCS signal to recover precise heartbeat intervals in the time domain.
針對NCS展示感測天線阻抗匹配效應，其中一組織匹配天線經展示以提供改良NCS信號品質及波形細節。分析生命徵象波形擷取之效能且論述設計策略。 To demonstrate the effect of sensing antenna impedance matching on NCS, one of the tissue-matched antennas was demonstrated to provide improved NCS signal quality and waveform details. Analyze the performance of vital signs waveform acquisition and discuss design strategies.
在另一實施例中，一心跳信號之高頻分量可用於緩解身體移動對心率估計之干擾。藉由以ECG為基準，NCS經展示為對於正常身體運動之即時心率及心率可變性係足夠精確的。 In another embodiment, the high-frequency component of a heartbeat signal can be used to mitigate the interference of body movement on heart rate estimation. By using the ECG as a benchmark, NCS has been shown to be accurate enough for real-time heart rate and heart rate variability during normal body movements.
在另一態樣中，本發明可體現為一種用於一個體之一身體上及/或身體內部運動之非接觸量測之方法。在待量測之一第一運動之一近場耦合範圍內提供一第一射頻(「RF」)感測信號。以此方式，可產生一第一量測信號作為藉由該第一運動調變之該第一感測信號。該第一感測信號可係一ID調變信號。該第一感測信號可係一主動無線電鏈路。該第一感測信號可係一反向散射RFID鏈路。該第一感測信號可由一無線標籤提供。可提供一下行鏈路信號以為該無線標籤充電。該第一感測信號可係該下行鏈路信號之一諧波。 In another aspect, the invention may be embodied as a method for non-contact measurement of movement on and/or within the body of a subject. A first radio frequency ("RF") sensing signal is provided within a near-field coupling range of a first motion to be measured. In this way, a first measurement signal can be generated as the first sensing signal modulated by the first motion. The first sensing signal may be an ID modulation signal. The first sensing signal may be an active radio link. The first sensing signal may be a backscattered RFID link. The first sensing signal may be provided by a wireless tag. A downlink signal can be provided to charge the wireless tag. The first sensing signal may be a harmonic of the downlink signal.
偵測該第一量測信號。基於該第一量測信號量測該第一運動。該第一量測信號可經偵測為透射穿過該第一運動之一源之後的遠場輻射。該第一量測信號可經偵測為從該第一運動之一源反射為天線反射。量測該第一運動可進一步包括濾波該第一量測信號以透過時序及波形獲得一第一運動信號。 Detect the first measurement signal. The first motion is measured based on the first measurement signal. The first measurement signal may be detected as far-field radiation transmitted through a source of first motion. The first measurement signal may be detected as an antenna reflection from a source of the first motion. Measuring the first motion may further include filtering the first measurement signal to obtain a first motion signal through timing and waveform.
在一些實施例中，該方法進一步包含在待量測之一第二運動之一近場耦合範圍內提供一第二RF感測信號。以此方式，可產生一第二量測信號作為藉由該第二運動調變之該第二感測信號。偵測該第二量測信號。基於該第二量測信號量測該第二運動。可基於同步量測之該第一運動及該第二運動量測一導數值。 In some embodiments, the method further includes providing a second RF sensing signal within a near-field coupling range of a second motion to be measured. In this manner, a second measurement signal can be generated as the second sensing signal modulated by the second motion. Detect the second measurement signal. The second motion is measured based on the second measurement signal. A derivative value may be measured based on the simultaneously measured first motion and the second motion.
在另一態樣中，提供一種用於量測一個體之運動之系統。該系統包含用於產生一第一感測信號之一第一信號源。一第一天線與該第一信號源電通信。該第一感測信號可係一ID調變波。該第一感測信號可係一主動無線電鏈路。該第一感測信號可係一反向散射RFID鏈路。該第一天線經組態以安置於待量測之一第一運動之一近場耦合範圍內。該第一天 線可經組態以安置於一心臟運動、一脈搏、一呼吸運動、一腸道運動、一眼睛運動等之一耦合範圍內。以此方式，產生一第一量測信號作為藉由該第一運動調變之該第一感測信號。該系統包含用於偵測一第一量測信號之一第一接收器。該第一接收器可經組態以將該第一量測信號偵測為一透射信號。該第一接收器可經組態以將該第一量測信號偵測為一反射信號。 In another aspect, a system for measuring motion of an entity is provided. The system includes a first signal source for generating a first sensing signal. A first antenna is in electrical communication with the first signal source. The first sensing signal may be an ID modulated wave. The first sensing signal may be an active radio link. The first sensing signal may be a backscattered RFID link. The first antenna is configured to be positioned within a near field coupling range of a first motion to be measured. The first day Lines can be configured to be placed within a coupling range of a heart movement, a pulse, a respiratory movement, a bowel movement, an eye movement, etc. In this way, a first measurement signal is generated as the first sensing signal modulated by the first motion. The system includes a first receiver for detecting a first measurement signal. The first receiver can be configured to detect the first measurement signal as a transmitted signal. The first receiver may be configured to detect the first measurement signal as a reflected signal.
該第一信號源及該第一天線可經組態為一無線標籤。一標籤讀取器經組態以將一下行鏈路信號傳輸至該無線標籤。該接收器可係該標籤讀取器之一部分。該無線標籤可經組態以由該下行鏈路信號充電。該第一感測信號可具有一頻率，該頻率係該下行鏈路信號之一頻率之一諧波。例如，該第一感測信號可係該下行鏈路信號之一第二諧波。該無線標籤可使用一正交ID調變該下行鏈路信號，使得該第一感測信號係一CDMA信號。 The first signal source and the first antenna may be configured as a wireless tag. A tag reader is configured to transmit a downlink signal to the wireless tag. The receiver may be part of the tag reader. The wireless tag can be configured to be charged by the downlink signal. The first sensing signal may have a frequency that is a harmonic of a frequency of the downlink signal. For example, the first sensing signal may be a second harmonic of the downlink signal. The wireless tag can use an orthogonal ID to modulate the downlink signal so that the first sensing signal is a CDMA signal.
在一些實施例中，該系統可進一步包含用於產生一第二感測信號之一第二信號源。一第二天線與該第二信號源電通信。該第二天線經組態以安置於待量測之一第二運動之一近場耦合範圍內以將一第二量測信號產生為藉由該第二運動調變之該第二感測信號。該接收器可經進一步組態以偵測該第二量測信號。 In some embodiments, the system may further include a second signal source for generating a second sensing signal. A second antenna is in electrical communication with the second signal source. The second antenna is configured to be positioned within a near-field coupling range of a second motion to be measured to generate a second measurement signal as the second sensing modulated by the second motion. signal. The receiver may be further configured to detect the second measurement signal.
在一些實施例中，一濾波器與該接收器通信。該濾波器可經組態以解調變及濾波該第一及/或第二量測信號以獲得一對應第一及/或第二運動信號。該濾波器可係例如經程式化以取樣、解調變及濾波該第一及/或第二量測信號以導出運動之一處理器。在一些實施例中，一處理器經程式化以基於所偵測耦合信號及第二耦合信號量測一導數值。 In some embodiments, a filter is in communication with the receiver. The filter may be configured to demodulate and filter the first and/or second measurement signals to obtain a corresponding first and/or second motion signal. The filter may be, for example, a processor programmed to sample, demodulate and filter the first and/or second measurement signals to derive motion. In some embodiments, a processor is programmed to measure a derivative value based on the detected coupled signal and the second coupled signal.
100:方法 100:Method
103:提供 103:Provide
106:偵測 106:Detection
109:量測 109:Measurement
112:濾波 112:Filtering
115:提供 115:Provide
118:偵測 118:Detection
121:量測 121:Measurement
124:濾波 124:Filtering
127:判定 127:Judgment
為更充分理解本發明之性質及目的，應參考結合附圖進行之以下實施方式，其中：圖1A描繪藉由近場同調感測(NCS)透過無線電傳輸對生命徵象進行之一CST Microwave Studio模擬模型，其中場型展示用於心跳感測之一身軀模擬模型中之共極化電場之實際部分。 To more fully understand the nature and purpose of the present invention, reference should be made to the following embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1A depicts a CST Microwave Studio simulation of vital signs via near field coherent sensing (NCS) over radio transmission Model with field patterns showing the actual part of the co-polarized electric field in a body simulation model used for heartbeat sensing.
圖1B描繪藉由NCS透過無線電傳輸對生命徵象進行之一CST Microwave Studio模擬模型，其中場型展示用於脈搏感測之一腕部模擬模型中之共極化電場之實際部分。 Figure 1B depicts a CST Microwave Studio simulation model of vital signs via radio transmission via NCS, with field patterns showing the actual portion of the co-polarized electric field in a wrist simulation model used for pulse sensing.
圖2A描繪具有一鄰近血管之一概念皮膚及組織結構之一NCS模擬，其中發射1.85GHz、0dBm信號之一偶極天線放置於皮膚上方且無需直接皮膚接觸。血管上方之組織包含皮膚、脂肪及肌肉。脈搏血管之幾何改變將調變近場且改變遠場反向散射場型。 Figure 2A depicts an NCS simulation of a conceptual skin and tissue structure with adjacent blood vessels, in which a dipole antenna emitting a 1.85 GHz, 0 dBm signal was placed over the skin without direct skin contact. The tissues above blood vessels include skin, fat, and muscle. Changes in the geometry of the pulsatile vessel will modulate the near field and change the far field backscatter pattern.
圖2B展示用於圖2A之準靜態血管之天線反射參數S11，其中橫剖面標記為t1、t2及t3。 Figure 2B shows the antenna reflection parameters S11 for the quasi-static blood vessel of Figure 2A, with cross-sections labeled t1, t2, and t3.
圖3A展示其中比較圖1A及圖1B之模擬振動振幅與遠場點處之取樣的一圖表。 Figure 3A shows a graph comparing the simulated vibration amplitudes of Figures 1A and 1B with sampling at a far-field point.
圖3B展示其中比較圖1A及圖1B之模擬振動振幅與由散射參數S11表示之天線反射處之取樣的一圖表。 Figure 3B shows a graph comparing the simulated vibration amplitudes of Figures 1A and 1B with the samples at the antenna reflection represented by the scattering parameter S11 .
圖4A展示用於心跳之模擬RF輻射場型，其中遠場樣本點在胸部前方1m。 Figure 4A shows a simulated RF radiation field pattern for a heartbeat, with the far-field sample point 1 m in front of the chest.
圖4B展示用於一腕部脈搏之模擬RF輻射場型，其中遠場樣本點在腕部上方1m。 Figure 4B shows simulated RF radiation field patterns for a wrist pulse with the far-field sample point 1 m above the wrist.
圖5A係根據本發明之一實施例之用於近場同調感測之一被動諧波 RFID標籤之一圖式。 Figure 5A shows a passive harmonic used for near-field coherent sensing according to an embodiment of the present invention. One of the schematics of RFID tags.
圖5B係根據本發明之一實施例之一諧波RFID讀取器之一圖式。 Figure 5B is a diagram of a harmonic RFID reader according to an embodiment of the present invention.
圖6A展示從一例示性諧波RFID系統解調變之一原始呼吸信號及低通濾波之後的波形。 Figure 6A shows the waveform after demodulating and low-pass filtering a raw respiratory signal from an exemplary harmonic RFID system.
圖6B展示從一例示性諧波RFID系統解調變之一原始心跳信號及十秒移動窗內之一平均心跳。標記展示來自安裝於左前臂上之OMRON血壓監測器之量測。 Figure 6B shows a raw heartbeat signal demodulated from an exemplary harmonic RFID system and an average heartbeat within a ten second moving window. The mark shows measurements from an OMRON blood pressure monitor mounted on the left forearm.
圖6C展示在三分鐘之資料收集期間之一心跳之波形。 Figure 6C shows the waveform of a heartbeat during a three-minute data collection period.
圖6D展示在三分鐘之資料收集期間之一腕部脈搏之波形。 Figure 6D shows a wrist pulse waveform during a three-minute data collection period.
圖6E展示動態時間扭曲(「DTW」)波形分析，其展示心跳之各波形之距離(插圖展示盒鬚分佈)。 Figure 6E shows a dynamic time warping ("DTW") waveform analysis showing the distance of each waveform of a heartbeat (the inset shows the box-whisker distribution).
圖6F展示DTW波形分析，其展示腕部脈搏之各波形之距離(插圖展示盒鬚分佈)。 Figure 6F shows DTW waveform analysis, which shows the distance of each waveform of the wrist pulse (the inset shows the box-whisker distribution).
圖6G展示與用於心跳之各自DTW模板相比較之中值距離波形及最大距離波形。 Figure 6G shows the median distance waveform and the maximum distance waveform compared to the respective DTW templates for heartbeats.
圖6H展示與用於腕部脈搏之各自DTW模板相比較之中值距離波形及最大距離波形。 Figure 6H shows the median distance waveform and the maximum distance waveform compared to the respective DTW templates for wrist pulses.
圖7A展示從同步心跳及腕部脈搏波形估計之脈波傳遞時間(「PTT」)。插圖展示信號及所提取PTT之一個週期。 Figure 7A shows the pulse transit time ("PTT") estimated from synchronized heartbeat and wrist pulse waveforms. The inset shows the signal and one period of the extracted PTT.
圖7B展示PTT在3分鐘內之概率密度分佈。 Figure 7B shows the probability density distribution of PTT within 3 minutes.
圖7C展示在受測試人員坐下時從PTT提取之血壓。星形標記展示從商用血壓監測器量測之血壓。 Figure 7C shows blood pressure extracted from the PTT while the subject was seated. The star mark shows blood pressure measured from a commercial blood pressure monitor.
圖7D展示在受測試人員經歷一適度活動且站立時從PTT提取之血 壓。星形標記展示從商用血壓監測器量測之血壓。 Figure 7D shows blood extracted from the PTT while the subject was undergoing a moderate activity and standing. pressure. The star mark shows blood pressure measured from a commercial blood pressure monitor.
圖8A係展示藉由反向散射與標籤互動之RFID讀取器之RF前端之一習知RFID系統之一圖式。 Figure 8A is a diagram of a conventional RFID system showing the RF front-end of an RFID reader that interacts with tags through backscattering.
圖8B係展示諧波RFID反向反射之本發明揭示原理之一實施例之一圖式，其中Tx表示傳輸器，Rx表示接收器，LPF表示低通濾波器，且HPF表示高通濾波器。 8B is a diagram illustrating an embodiment of the disclosed principle of harmonic RFID back reflection, where Tx represents a transmitter, Rx represents a receiver, LPF represents a low-pass filter, and HPF represents a high-pass filter.
圖9A係與織物上之刺繡天線整合之本發明之一實施例之一RFID感測器標籤晶片之一照片。 Figure 9A is a photograph of an RFID sensor tag chip integrated with an embroidered antenna on fabric according to one embodiment of the present invention.
圖9B係根據本發明之一實施例之一諧波RFID標籤之一PCB原型之一照片。 FIG. 9B is a photograph of a PCB prototype of a harmonic RFID tag according to an embodiment of the present invention.
圖10展示具有各種系統SNR下之CDMA(200個標籤)之一諧波RFID標籤之定位誤差。 Figure 10 shows the positioning error of one harmonic RFID tag for CDMA (200 tags) with various system SNRs.
圖11展示具有各種SNR下之CDMA之諧波反向散射之取樣率，其中標籤數目在讀取範圍內。當晶片碼長度與標籤數目成比例時，實線係來自CDMA。虛線表示具有更有效半正交碼之實施方案。 Figure 11 shows the sampling rate of harmonic backscatter for CDMA with various SNRs, where the number of tags is within the read range. The solid line is from CDMA when the chip code length is proportional to the number of tags. The dashed line represents an implementation with more efficient semi-orthogonal codes.
圖12A係展示根據本發明之一實施例之一天線反射系統之一圖式。分離器係雙向的且可由一寬頻循環器替代。諧波收發器及諧波產生器類似於圖5A及圖5B之被動標籤系統中使用之諧波收發器及諧波產生器。 FIG. 12A is a diagram showing an antenna reflection system according to an embodiment of the present invention. The splitter is bidirectional and can be replaced by a broadband circulator. The harmonic transceiver and harmonic generator are similar to those used in the passive tag system of Figures 5A and 5B.
圖12B係展示使用圖12A之天線反射系統之經量測心跳波形之一圖式。 FIG. 12B is a diagram showing a measured heartbeat waveform using the antenna reflection system of FIG. 12A.
圖13展示當根據本發明之一實施例之一近場同調感測天線放置於一非對稱軸直流電減速馬達附近時之校準結果。解調變正弦波形係2D週期性非對稱旋轉之1D相位投影。 FIG. 13 shows the calibration results when a near-field coherent sensing antenna according to an embodiment of the present invention is placed near an asymmetrical axis DC reduction motor. The demodulated sinusoidal waveform is a 1D phase projection of 2D periodic asymmetric rotation.
圖14係用於耦合至心臟運動之天線近場之處於1.8GHz之共極化電場之電磁波模擬之一橫剖面。 Figure 14 is a cross-section of an electromagnetic wave simulation of a co-polarized electric field at 1.8 GHz for an antenna near field coupled to cardiac motion.
圖15係展示藉由標籤1之所收集馬達旋轉原始資料及對資料進行帶通濾波後的曲線之一圖式。 Figure 15 is a diagram showing the raw motor rotation data collected through tag 1 and the curve after band-pass filtering the data.
圖16係展示藉由標籤2針對具有500Hz之取樣頻率之一心跳波形收集之原始資料之一圖式。 Figure 16 is a diagram showing the raw data collected by Tag 2 for a heartbeat waveform with a sampling frequency of 500 Hz.
圖17係展示從圖16提取之1.4Hz至15Hz帶通濾波之後的心跳波形之一圖式。 FIG. 17 is a diagram showing the heartbeat waveform extracted from FIG. 16 after band-pass filtering from 1.4 Hz to 15 Hz.
圖18係從圖16提取之心跳波形之一個循環，其中繪示特性點。 Figure 18 is a cycle of the heartbeat waveform extracted from Figure 16, in which characteristic points are shown.
圖19展示從一胸部標籤(實線)及腕部標籤(虛線)記錄之一信號。時序差異給出血壓之一估計。 Figure 19 shows a signal recorded from a chest tag (solid line) and a wrist tag (dashed line). The timing difference gives an estimate of blood pressure.
圖20係從圖17提取之心跳波形及腕部脈搏波形之一個循環，其中繪示兩個C峰值點。峰值1與峰值2之間的延遲係約0.074s，其轉變成約88mmHg之舒張壓。 Figure 20 is a cycle of the heartbeat waveform and wrist pulse waveform extracted from Figure 17, in which two C peak points are shown. The delay between Peak 1 and Peak 2 is approximately 0.074 seconds, which translates into a diastolic blood pressure of approximately 88 mmHg.
圖21係展示根據本發明之另一實施例之一方法之一流程圖。 Figure 21 is a flowchart showing a method according to another embodiment of the present invention.
圖22A係一諧波RFID反向散射標籤之一示意圖。 Figure 22A is a schematic diagram of a harmonic RFID backscatter tag.
圖22B係在圖22A中描繪之標籤之一PCB原型之一照片。 Figure 22B is a photograph of a PCB prototype of the label depicted in Figure 22A.
圖23係展示一實驗NCS設定之一照片。一第一標籤在胸部區域中且第二標籤在左腕上。感測波形展示在螢幕上。胸帶及腕帶在此處僅為部署便利。無需皮膚接觸或帶張力。 Figure 23 is a photograph showing an experimental NCS setup. A first label is in the chest area and a second label is on the left wrist. The sensed waveform is displayed on the screen. The chest strap and wrist strap are here only for deployment convenience. No skin contact or tension required.
圖24A至圖24B係從胸部標籤NCS信號提取之心跳及呼吸波形。(A)主要藉由心跳調變NCS信號之振幅。頂部曲線係來自正規化振幅，其穿過數位BPF(0.8Hz至15Hz)以給出底部曲線。(B)主要藉由呼吸運動調變 NCS信號之相位。頂部曲線係正規化原始相位，其穿過數位BPF(0.1Hz至1.2Hz)以給出底部曲線。正交接收器中之振幅與相位調變之間的隔離致使呼吸波形與心跳波形之間的明確分離。 Figures 24A to 24B are heartbeat and respiratory waveforms extracted from chest tag NCS signals. (A) The amplitude of the NCS signal is modulated mainly by heartbeat. The top curve is from the normalized amplitude, which is passed through the digital BPF (0.8Hz to 15Hz) to give the bottom curve. (B) Mainly modulated by breathing movements Phase of NCS signal. The top curve is the normalized raw phase, which is passed through the digital BPF (0.1Hz to 1.2Hz) to give the bottom curve. The isolation between amplitude and phase modulation in the quadrature receiver results in a clear separation between the respiratory waveform and the heartbeat waveform.
圖25A至圖25C係(A)同步時域NCS(實線)及ECG(點劃線)心跳信號。NCS之取樣率係5,000Sps，且ECG最初具有512Sps但增加取樣至5,000Sps。(B)NCS信號之頻譜，其中強度經正規化至約1Hz之峰值且放大以清晰展示較低強度部分。(C)ECG信號之頻譜，其中強度亦經正規化至約1Hz之峰值且放大以展示較低強度部分。2Hz與8Hz之間的高頻分量比NCS中之高頻分量更突出。 Figures 25A to 25C are (A) synchronized time domain NCS (solid line) and ECG (dashed line) heartbeat signals. The sampling rate of NCS is 5,000Sps, and the ECG initially has 512Sps but increases the sampling to 5,000Sps. (B) Spectrum of the NCS signal with the intensity normalized to a peak at approximately 1 Hz and amplified to clearly show the lower intensity portion. (C) Spectrum of the ECG signal with the intensity also normalized to a peak at approximately 1 Hz and amplified to show the lower intensity portion. The high-frequency components between 2Hz and 8Hz are more prominent than those in NCS.
圖26A至圖26B係(A)高頻等化之後的時域NCS信號。三角形標記展示用於心跳時間間隔提取之尖銳峰值特徵點。(B)NCS及ECG信號之心跳時間間隔。虛線、點劃線及實線分別來自原始NCS(NCS1)、ECG及等化NCS(NCS2)。 Figure 26A to Figure 26B are (A) the time domain NCS signal after high frequency equalization. Triangular markers show sharp peak feature points used for heartbeat time interval extraction. (B) Heartbeat time interval of NCS and ECG signals. The dashed line, dotted line and solid line are respectively from the original NCS (NCS1), ECG and equalized NCS (NCS2).
圖27A至圖27B係NCS天線效應：(A)CST Microwave Studio中之一胸部RFID標籤之EM模擬模型。(B)用於標籤天線之模擬S11參數。 Figure 27A to Figure 27B show the NCS antenna effect: (A) EM simulation model of a chest RFID tag in CST Microwave Studio. (B) Simulated S 11 parameters for tag antenna.
圖28A至圖28B係耦合至人體身軀中之NCS信號之處於2GHz之模擬EM功率流，其中(A)具有較差阻抗匹配且(B)具有適當阻抗匹配。 Figures 28A-28B are simulated EM power flows at 2 GHz coupled to NCS signals in the human body, with (A) having a poor impedance match and (B) having an adequate impedance match.
圖29A至圖29B係各種頻率中之實驗結果。(A)NCS天線在空氣中操作(實曲線)及放置於胸部上(虛曲線)時之S11。(B)從圖4中之胸部標籤解調變之心跳信號波形，其等具有不同感測頻率。來自實曲線(阻抗匹配條件)、虛曲線及點劃曲線之NCS信號分別對應於圖5A中之頻率1、2及3。 Figures 29A to 29B are experimental results at various frequencies. (A) S 11 when the NCS antenna is operated in air (solid curve) and placed on the chest (dashed curve). (B) Heartbeat signal waveform demodulated from the chest tag in Figure 4, which has different sensing frequencies. The NCS signals from the solid curve (impedance matching condition), dashed curve and dot-dashed curve correspond to frequencies 1, 2 and 3 in Figure 5A respectively.
圖30係藉由導電油墨使用織物天線在電子產品碼(EPC)協定上運行之一例示性標籤之一照片。 Figure 30 is a photograph of an exemplary tag running over the Electronic Product Code (EPC) protocol using conductive ink using a fabric antenna.
圖31展示使用NCS從一胸部標籤提取之心跳及呼吸波形之實驗結果。 Figure 31 shows the experimental results of heartbeat and respiratory waveforms extracted from a chest tag using NCS.
圖32A至圖32B係在大身體移動從40s開始時之NCS信號。(A)時域中之NCS信號之振幅。插圖係在受測試人員靜坐時的前40s中之解調變心跳波形。(B)在無移動之10s至30s期間的NCS頻譜(深灰)及具有大身體移動之85s至105s期間的NCS頻譜(淺灰)。 Figure 32A to Figure 32B are the NCS signals when the large body movement starts from 40s. (A) Amplitude of NCS signal in time domain. The illustration shows the demodulated heartbeat waveform in the first 40 seconds when the subject is sitting quietly. (B) NCS spectrum during 10s to 30s without movement (dark gray) and NCS spectrum during 85s to 105s with large body movement (light gray).
圖33A至圖33C係經提取心率。(A)用於心跳計數之三次諧波NCS信號(實線)及用於約97s之心跳參考之ECG信號(虛線)。(B)藉由NCS(實線)及ECG(虛線)計數心跳。底部線指示誤差(標記為ERROR)。插圖係在大身體移動在40s之後發生時的25s至55s期間的結果。(C)藉由NCS(實線)及ECG(虛線)監測之即時心率曲線。 Figures 33A to 33C show the extracted heart rate. (A) Third harmonic NCS signal for heartbeat counting (solid line) and ECG signal for heartbeat reference at approximately 97 s (dashed line). (B) Counting of heartbeats by NCS (solid line) and ECG (dashed line). The bottom line indicates the error (labeled ERROR). The inset shows results from the period 25 to 55 s when large body movements occur after 40 s. (C) Real-time heart rate curve monitored by NCS (solid line) and ECG (dashed line).
圖34係用於呼吸、心跳及運動偵測之NCS設定。在胸部區域中部署一被動諧波RFID標籤且將諧波頻率反向散射至讀取器天線。對藉由SDR實施之諧波讀取器執行即時解調變及資料分析。 Figure 34 shows the NCS settings for breathing, heartbeat and motion detection. A passive harmonic RFID tag is deployed in the chest area and backscatters harmonic frequencies to the reader antenna. Perform real-time demodulation and data analysis on harmonic readers implemented via SDR.
圖35A係DC濾波振幅及相位資料之一圖表。 Figure 35A is a graph of DC filter amplitude and phase data.
圖35B係展示呼吸之一圖表。 Figure 35B is a diagram showing breathing.
圖35C係展示心跳之一圖表。 Figure 35C is a diagram showing a heartbeat.
圖35D係展示峰值偵測之心跳之一圖表。 Figure 35D is a graph showing peak detected heartbeats.
圖36A至圖36C係展示使用NCS獲得之心跳及對應運動偵測之圖表。 Figures 36A to 36C are graphs showing heartbeats and corresponding motion detection obtained using NCS.
圖37A至圖37B係用於有意識小動物之生命徵象之近場同調感測(NCS)之兩個設定。藉由諧波讀取器收集信號且使用場可程式化閘極陣列(FPGA)及微控制器(MCU)進行數位基頻帶處理。(A)藉由具有被動諧波感測標籤之諧波RFID系統實現無線NCS系統。(B)有線NCS系統將讀取器與 諧波標籤之間的無線鏈路替換為RF纜線以減小干擾且便於室內實驗室部署。 Figures 37A-37B are two settings for near-field coherent sensing (NCS) of vital signs of conscious small animals. Signals are collected with a harmonic reader and digitally processed at the baseband using a field programmable gate array (FPGA) and a microcontroller (MCU). (A) Wireless NCS system is implemented through a harmonic RFID system with passive harmonic sensing tags. (B) The wired NCS system connects the reader to Wireless links between harmonic tags are replaced with RF cables to reduce interference and facilitate indoor laboratory deployment.
圖38A係使用同步NCS及ECG量測之一麻醉大鼠之一實驗設定之一照片。 Figure 38A is a photograph of an experimental setup using simultaneous NCS and ECG measurements on an anesthetized rat.
圖38B展示來自圖38A之實驗設定之NCS及ECG之5分鐘資料記錄。插圖展示一選定半秒持續時間內之波形細節。 Figure 38B shows a 5-minute data record of NCS and ECG from the experimental setup of Figure 38A. The inset shows waveform details for a selected half-second duration.
圖38C展示從NCS提取之一心跳時間間隔，其展示與ECG信號之一緊密匹配。 Figure 38C shows one of the heartbeat time intervals extracted from the NCS, shown to closely match one of the ECG signals.
圖38D展示在約第三秒至第四秒從NCS信號之相位解調變之代表性呼吸信號。 Figure 38D shows a representative respiratory signal from phase demodulation of the NCS signal at approximately third to fourth seconds.
圖39A至圖39L展示使用非侵入性NCS設定對有意識小動物進行之生命徵象監測。(A)用於倉鼠之實驗設定。(B)從NCS信號解調變之心跳及呼吸信號。插圖展示約第八秒之心跳波形細節。(C)約30秒之心跳時間間隔。(D)用於長尾鸚鵡之有線NCS設定。(E)從NCS信號解調變之心跳及呼吸信號。(F)約1.5分鐘之經提取心跳時間間隔。(G)用於類似於圖39D之四爪陸龜之NCS設定，其中天線在木屑地板下方。(H)三分鐘之NCS信號之正規化原始振幅，其歸因於殼體結構而表示呼吸及心跳兩者。插圖展示重疊信號之波形細節。淺陰影區段指示心跳，而深陰影區段指示呼吸。強呼吸信號將在重疊期間覆蓋心跳信號。(I)在與(H)相同之週期期間藉由連續小波波形(CWT)線上處理之信號展示用於精確率估計之心跳及呼吸之明確分離。插圖展示經提取波形細節，其清楚指示心跳及呼吸中之每一峰值。(J)用於斗魚之類似於圖39D之NCS設定。在靠近魚之水中部署Tx及Rx天線。(K)由胸鰭移動引起之解調變NCS相位信號，其中插圖展示波形細 節。(L)可能由心跳引起之解調變NCS量值信號。 Figures 39A-39L illustrate vital signs monitoring of a conscious small animal using a non-invasive NCS setup. (A) Experimental setup for hamsters. (B) Heartbeat and respiration signals demodulated from the NCS signal. The illustration shows details of the heartbeat waveform at about the eighth second. (C) Heartbeat interval of approximately 30 seconds. (D) Wired NCS setup for parakeets. (E) Heartbeat and respiration signals demodulated from the NCS signal. (F) About 1.5 minutes of extracted heartbeat time interval. (G) NCS setup for a four-clawed tortoise similar to Figure 39D, with the antenna under the woodchip floor. (H) Normalized raw amplitude of three minutes of NCS signal representing both respiration and heartbeat due to shell structure. The inset shows the waveform details of the overlapping signals. Lightly shaded segments indicate heartbeat, while darkly shaded segments indicate respiration. A strong breathing signal will cover the heartbeat signal during the overlap. (I) Signals processed online by continuous wavelet waveforms (CWT) during the same period as (H) demonstrate clear separation of heartbeat and respiration for accurate rate estimation. The inset shows the extracted waveform details, which clearly indicate each peak in heartbeat and respiration. (J) NCS setup similar to Figure 39D for betta fish. Deploy Tx and Rx antennas in the water near the fish. (K) Demodulated NCS phase signal caused by pectoral fin movement, in which the inset shows the waveform details. section. (L) Demodulated NCS magnitude signal possibly caused by heartbeat.
圖40係描繪根據本發明之另一實施例之一系統之一圖式。 Figure 40 is a diagram depicting a system according to another embodiment of the present invention.
本發明係在能源部授予的第DE-AR0000528號合約下由政府支援而實現。政府具有對本發明之某些權力。 This invention was made possible with government support under Contract No. DE-AR0000528 awarded by the Department of Energy. The government has certain rights in this invention.
本申請案主張2017年6月16日申請之現審查中之美國臨時申請案第62/521,163號及2018年1月17日申請之現審查中之美國臨時申請案第62/618,352號之優先權，該等案之揭示內容以引用的方式併入本文中。 This application claims priority to the currently pending US Provisional Application No. 62/521,163, filed on June 16, 2017, and the currently pending US Provisional Application No. 62/618,352, filed on January 17, 2018. , the disclosure contents of these cases are incorporated into this article by reference.
生命徵象不僅對於病理研究係重要的，而且亦可由穿戴式裝置廣泛用於推斷行為、情緒及健康。儘管良好建立且廣泛應用許多此等裝置，但當前裝置具有限制其等感測精確性或長期便利性之缺點。本發明可體現為一種用於近場同調感測(「NCS」)之方法，其將一個體之移動調變至射頻(「RF」)信號上，射頻信號可係多工RF信號。一個體之移動可包含例如關於生命徵象之移動，例如心跳、脈搏、呼吸等。本發明方法之實施例可將個體之身體表面上或身體內部之機械運動直接調變至近場範圍內之RF信號上。可使用唯一數位識別(「ID」)將運動調變至多工諧波RF識別(「RFID」)反向散射信號上。 Vital signs are not only important for pathological research, but can also be widely used by wearable devices to infer behavior, emotion and health. Although many of these devices are well established and widely used, current devices have shortcomings that limit their sensing accuracy or long-term convenience. The present invention may be embodied as a method for near-field coherent sensing ("NCS"), which modulates the movement of an individual onto a radio frequency ("RF") signal, which may be a multiplexed RF signal. The movement of a body may include, for example, movement related to vital signs, such as heartbeat, pulse, respiration, etc. Embodiments of the method of the present invention can directly modulate mechanical motions on or within an individual's body to RF signals in the near-field range. A unique digital identification ("ID") can be used to modulate motion onto a multiplexed harmonic RF identification ("RFID") backscattered signal.
一天線之「近場」係其中感應特性主導優勢高於輻射特性且未良好界定電場(E場)與磁場(H場)之間的關係之一區域。在本發明之實施例中，「近場」可指一天線之接近區域，其中角視場分佈取決於距天線 之距離。在實施例中，近場延伸至天線之一個波長(λ)內之區域。在其他實施例中，近場延伸至天線之λ/2、λ/3、λ/4或λ/2π內之區域，其中λ係天線之操作波長。憑藉本發明之益處，熟習此項技術者將明白其他實施例。 The "near field" of an antenna is a region where inductive characteristics dominate over radiation characteristics and the relationship between the electric field (E field) and the magnetic field (H field) is not well defined. In embodiments of the present invention, "near field" may refer to a close area of an antenna, where the angular field of view distribution depends on the distance from the antenna. distance. In embodiments, the near field extends to a region within one wavelength (λ) of the antenna. In other embodiments, the near field extends to a region within λ/2, λ/3, λ/4, or λ/2π of the antenna, where λ is the operating wavelength of the antenna. Other embodiments will be apparent to those skilled in the art having the benefit of the present invention.
參考圖21，本發明可體現為一種用於一個體之一身體運動(例如，身體上或身體內部運動)之非接觸量測之方法100。個體可係例如一人類或一非人類動物。所偵測運動可係例如一心臟運動、一脈搏、一呼吸運動、一腸道運動、一眼睛運動或如鑑於本發明將明白之其他身體運動。本發明方法100之實施例可將個體之身體表面上或身體內部之機械運動直接調變至與一唯一數位ID整合之多工無線電信號上。在待量測之一第一運動之一近場耦合範圍內提供103一第一射頻(「RF」)感測信號以產生一量測信號。所提供103第一感測信號可係一ID調變信號。在一些實施例中，第一感測信號係一主動無線電鏈路。在一些實施例中，第一感測信號係一反向散射RFID鏈路。例如，一天線可在一主動無線電鏈路或一反向散射RFID(無線電識別)鏈路中發射一信標或ID調變感測信號。將藉由第一運動調變第一感測信號，藉此產生一第一量測信號。方法100包含偵測106第一量測信號。在一些實施例中，偵測106可在遠場處完成，例如偵測傳輸通過個體之身體之第一量測信號。在一些實施例中，偵測106具有一反射信號，例如使用近場天線。 Referring to FIG. 21 , the present invention may be embodied as a method 100 for non-contact measurement of body movement of an individual (eg, movement on or within the body). The individual may be, for example, a human or a non-human animal. The detected movement may be, for example, a heart movement, a pulse, a breathing movement, an intestinal movement, an eye movement or other body movement as will be understood in view of the present invention. Embodiments of the method 100 of the present invention may directly modulate mechanical motion on or within an individual's body to a multiplexed radio signal integrated with a unique digital ID. A first radio frequency ("RF") sensing signal is provided 103 within a near-field coupling range of a first motion to be measured to generate a measurement signal. The first sensing signal provided 103 may be an ID modulation signal. In some embodiments, the first sensed signal is an active radio link. In some embodiments, the first sensing signal is a backscattered RFID link. For example, an antenna may transmit a beacon or ID modulated sensing signal in an active radio link or a backscatter RFID (radio identification) link. The first sensing signal will be modulated by the first movement, thereby generating a first measurement signal. Method 100 includes detecting 106 a first measurement signal. In some embodiments, detection 106 may be accomplished in the far field, such as detecting a first measurement signal transmitted through the individual's body. In some embodiments, detection 106 has a reflected signal, such as using a near-field antenna.
基於第一量測信號量測109第一運動。如上文提及，在NCS中，將比先前技術更多之能量引導至身體組織中，因此隱含地放大來自內臟之反向散射信號。而且，身體組織內之較短波長將一小機械運動呈現為一相對大相位變化。個體之身體內之較短波長自然地增大信雜比(「SNR」)。身體內信號之差分性質可隔離大表面移動。此亦可增大敏感 度，從而實現一弱運動信號(諸如例如一腕部脈搏)之量測。由於內部機械運動調變給出類似於一干擾計之一差分信號，故可藉由濾波容易地低降由外部移動導致之共同信號(例如，見圖2A)。憑藉在身體內部之機械運動之近場耦合範圍內之一天線，傳播或反射波可以一同調方式容易地偵測且將含有機械運動之即時幾何平均資訊。可藉由濾波112第一量測信號以獲得一運動信號而量測運動。在ID調變波之情況中，可以一同步方式同時讀取多個機械運動。可在被動反向散射或主動無線電傳輸中使用多工技術以促進在多個點及/或對多個人員之同時感測。NCS提供具有舒適性、便利性及低成本之生命徵象監測之新機會。 The first motion is measured 109 based on the first measurement signal. As mentioned above, in NCS more energy is directed into body tissue than in previous techniques, thus implicitly amplifying the backscattered signal from the viscera. Furthermore, shorter wavelengths within body tissue present small mechanical motions as relatively large phase changes. Shorter wavelengths within an individual's body naturally increase the signal-to-noise ratio ("SNR"). The differential nature of signals within the body can isolate large surface movements. This can also increase sensitivity degree, thereby achieving the measurement of a weak motion signal (such as a wrist pulse). Since internal mechanical motion modulation gives a differential signal similar to an interferometer, common signals caused by external motion can be easily reduced by filtering (eg, see Figure 2A). With an antenna within the near-field coupling range of mechanical motion inside the body, propagated or reflected waves can be easily detected in a coherent manner and will contain real-time geometric mean information of the mechanical motion. Motion can be measured by filtering 112 the first measurement signal to obtain a motion signal. In the case of ID modulated waves, multiple mechanical movements can be read simultaneously in a synchronized manner. Multiplexing techniques can be used in passive backscatter or active radio transmission to facilitate simultaneous sensing at multiple points and/or of multiple persons. NCS provides new opportunities for vital sign monitoring with comfort, convenience and low cost.
應注意，本發明揭示之NCS技術直接量測一身體內部或身體上之機械運動，而非間接藉由例如感測感應機械運動之電神經信號或由機械運動感應之電信號。因此，本發明NCS技術可提供比一習知心電圖更豐富之資訊。例如，藉由在其中可感受一脈搏之腕部或頸部區域上使用一第二標籤，來自一心臟標籤之波形差異可用於獲得血壓之一精確估計，且此可對房間內之多人進行而無歧義。使用本發明技術，可以一全新方式管理臨床領域：穿戴根據本發明之(若干)標籤之所有人可監測其等之ID、位置、心率、呼吸率、血壓等。另外，由於無需皮膚接觸(例如，相較於(若干)ECG襯墊)，故可完成一個體之長期監測。 It should be noted that the NCS technology disclosed in the present invention directly measures mechanical motion within or on the body, rather than indirectly by, for example, sensing electrical nerve signals that sense mechanical motion or electrical signals that are sensed by mechanical motion. Therefore, the NCS technology of the present invention can provide richer information than a conventional electrocardiogram. For example, by using a second tag on the wrist or neck area where a pulse can be felt, waveform differences from a heart tag can be used to obtain an accurate estimate of blood pressure, and this can be done for multiple people in the room. without ambiguity. Using the technology of the invention, the clinical field can be managed in a completely new way: all persons wearing tag(s) according to the invention can monitor their ID, location, heart rate, respiration rate, blood pressure, etc. Additionally, since no skin contact is required (eg, compared to (several) ECG pads), long-term monitoring of an individual can be accomplished.
在一些實施例中，方法100可進一步包含在待量測之一第二運動之一近場耦合範圍內提供115一第二RF感測信號。以此方式，第二運動耦合至第二RF感測信號以產生一第二量測信號。偵測118第二量測信號，且基於第二量測信號量測121第二運動。可藉由濾波124第二量測信號以獲得一第二運動信號而量測第二運動。可基於同步量測之運動及第二 運動判定127一導數值。例如，在第一運動係一心跳(在胸部附近量測)且第二運動係一脈搏(在腕部附近量測)之情況下，導數值可係基於心跳及脈搏判定127之一血壓。 In some embodiments, the method 100 may further include providing 115 a second RF sensing signal within a near-field coupling range of a second motion to be measured. In this manner, the second motion is coupled to the second RF sensing signal to generate a second measurement signal. Detect 118 the second measurement signal, and measure 121 the second motion based on the second measurement signal. The second motion may be measured by filtering 124 the second measurement signal to obtain a second motion signal. Can be based on simultaneous measurement of motion and second Motion determination 127 - derivative value. For example, where the first movement is a heartbeat (measured near the chest) and the second movement is a pulse (measured near the wrist), the derivative value may be a blood pressure based on the heartbeat and pulse determination 127 .
在另一態樣中，本發明可體現為一種用於量測一個體之運動之系統10(例如，見圖40)。系統10包含用於產生一第一感測信號之一第一信號源12。一第一天線14與第一信號源12電通信。第一天線14經組態以安置於待量測之一第一運動之一近場耦合範圍內。例如，第一天線14可經組態以安置於一心臟運動、一脈搏、一呼吸運動、一腸道運動、一眼睛運動等之一耦合範圍內。以此方式，由藉由第一運動調變之第一感測信號產生一第一量測信號。第一感測信號可係一ID調變波。例如，EM波可係一主動無線電鏈路或一反向散射RFID鏈路。 In another aspect, the present invention may be embodied as a system 10 for measuring the movement of an individual (eg, see Figure 40). System 10 includes a first signal source 12 for generating a first sensing signal. A first antenna 14 is in electrical communication with the first signal source 12 . The first antenna 14 is configured to be positioned within a near-field coupling range of a first motion to be measured. For example, the first antenna 14 may be configured to be positioned within a coupling range of a heart movement, a pulse, a respiratory movement, an intestinal movement, an eye movement, etc. In this way, a first measurement signal is generated from the first sensing signal modulated by the first motion. The first sensing signal may be an ID modulated wave. For example, the EM waves can be an active radio link or a backscatter RFID link.
系統包含用於偵測第一量測信號(與第一運動耦合(藉由第一運動調變)之第一感測信號)之一接收器16。接收器16可經組態以將第一量測信號偵測為一透射信號，即，遠場輻射。接收器可經組態以將第一量測信號偵測為一反射信號，即，天線反射。系統可包含與接收器通信之一濾波器，其中濾波器經組態以解調變及濾波第一量測信號以獲得一運動信號。濾波器可係例如經程式化以取樣、解調變及/或濾波第一量測信號以導出運動信號之一處理器(諸如一數位信號處理器(「DSP」))。 The system includes a receiver 16 for detecting a first measurement signal (a first sensing signal coupled to the first motion (modulated by the first motion)). Receiver 16 may be configured to detect the first measurement signal as a transmitted signal, ie, far-field radiation. The receiver may be configured to detect the first measurement signal as a reflected signal, ie, an antenna reflection. The system may include a filter in communication with the receiver, wherein the filter is configured to demodulate and filter the first measurement signal to obtain a motion signal. The filter may be, for example, a processor (such as a digital signal processor ("DSP")) programmed to sample, demodulate and/or filter the first measurement signal to derive a motion signal.
在一些實施例中，一系統10可包含用於產生一第二感測信號之一第二信號源22。在此等實施例中，一第二天線24與第二信號源22電通信。第二天線24經組態以安置於待量測之一第二運動之一近場耦合範圍內。以此方式，可產生一第二量測信號作為藉由第二運動調變之第二感測信號。在一特定實例中，第一運動係一心跳且第二運動係一脈搏。在此 一實例中，第一天線可經組態以接近於一個體之胸部安置，且第二天線經組態以接近於個體之腕部安置。接收器16經進一步組態以偵測第二量測信號。系統10可包含用於基於所偵測第一量測信號及第二量測信號量測一導數值之一處理器30。在一心跳及脈搏之特定實例中，導數值可係例如個體之一血壓。 In some embodiments, a system 10 may include a second signal source 22 for generating a second sensing signal. In these embodiments, a second antenna 24 is in electrical communication with the second signal source 22 . The second antenna 24 is configured to be positioned within a near field coupling range of a second motion to be measured. In this manner, a second measurement signal can be generated as the second sensing signal modulated by the second motion. In a specific example, the first movement is a heartbeat and the second movement is a pulse. here In one example, a first antenna may be configured to be positioned proximate an individual's chest, and a second antenna may be configured to be positioned proximate a wrist of the individual. Receiver 16 is further configured to detect the second measurement signal. System 10 may include a processor 30 for measuring a derivative value based on the detected first measurement signal and the second measurement signal. In the specific example of a heartbeat and pulse, the derivative value may be, for example, an individual's blood pressure.
在一些實施例中，無線標籤(諸如被動(即，不具有諸如一電池之本端電源)RFID標籤)可整合至其中待量測生命徵象之區域附近之服裝中。此等RFID標籤可提供具有低部署及維護成本之一NCS實施方案。此等RFID標籤可提供ID調變信號，其中各標籤之一唯一ID有助於區分其信號與來自其他標籤及周圍信號之干擾。接著使用頻譜等化處理標籤反向散射信號以放大高頻分量，以不僅復原最初浸沒於低頻分量中之波形細節，而且亦復原具有改良峰值偵測確定性之精確心跳時間間隔之尖銳峰值。與同步ECG相比較，所導出心跳時間間隔展現改良穩定性。 In some embodiments, wireless tags, such as passive (ie, without a local power source such as a battery) RFID tags, may be integrated into clothing near the area in which vital signs are to be measured. These RFID tags provide an NCS implementation with low deployment and maintenance costs. These RFID tags provide an ID modulated signal, where a unique ID for each tag helps distinguish its signal from interference from other tags and surrounding signals. The tag backscattered signal is then processed using spectral equalization to amplify the high frequency components to restore not only the waveform details originally submerged in the low frequency components, but also the sharp peaks of precise heartbeat intervals with improved peak detection certainty. The derived heartbeat intervals exhibit improved stability compared to synchronized ECGs.
NCS之實施例利用一EM場至一身體內部或身體表面上之機械運動的近場耦合。使用CST Microwave Studio進行電磁模擬以繪示NCS之操作原理。如圖1A及圖1B中展示，建構一男性身軀(1A)及一左下臂(1B)之EM模擬。基於Zubal Phantom建構EM模擬模型，Zubal Phantom具有3.6×3.6×3.6mm3之立體像素解析度且由磁共振成像(「MRI」)及電腦斷層掃描(「CT」)建立。各立體像素由人體組織之3D座標連同指數一起指示。在CST匯入身軀模型之後，Visual Basic for Applications(「VBA」)巨集語言用於使用CST生物庫映射EM性質。接著採用有限積分技術(「FIT」)以包含胸部區域附近之RFID標籤天線。如 從模擬可見，大量RF能量歸因於近場耦合而耦合於身軀內部。由於人體組織之高介電常數，波長相應地變短，此進一步增大NCS敏感度。 Embodiments of NCS utilize near-field coupling of an EM field to mechanical motion within a body or on a body surface. Electromagnetic simulations were performed using CST Microwave Studio to illustrate the operating principle of the NCS. As shown in Figures 1A and 1B, an EM simulation of a male body (1A) and a left lower arm (1B) is constructed. An EM simulation model is constructed based on Zubal Phantom, which has a voxel resolution of 3.6×3.6× 3.6mm3 and is created by magnetic resonance imaging (“MRI”) and computed tomography (“CT”). Each voxel is indicated by the 3D coordinates of the human tissue together with an index. After CST imports the body model, the Visual Basic for Applications (“VBA”) macro language is used to map EM properties using the CST biobank. Finite Integration Technology ("FIT") is then used to include the RFID tag antenna near the chest area. As can be seen from the simulation, a large amount of RF energy is coupled inside the body due to near-field coupling. Due to the high dielectric constant of human tissue, the wavelength is correspondingly shortened, which further increases NCS sensitivity.
本發明NCS方法使用電磁場之振幅及相位兩者。由於相位對RF源與接收器之間的距離非常敏感，故因此可藉由相位評估一人員呼吸時之外部胸部移動。可容易地擷取呼吸率且可使用相位變化進一步解釋呼吸運作。與相位資訊相比較，電磁場之振幅對小距離變化不那麼敏感，此意謂呼吸或其他外部身體移動將改變相位而非振幅，從而提供待適當感測之身體內部之其他信號之良好隔離。在NCS中，干擾量測類結構將內臟/組織移動轉換為RF信號之振幅調變。 The present NCS method uses both the amplitude and phase of the electromagnetic field. Since phase is very sensitive to the distance between the RF source and the receiver, it can be used to evaluate the external chest movement of a person breathing. Respiration rate can be easily captured and phase changes can be used to further explain the workings of breathing. Compared to phase information, the amplitude of the electromagnetic field is less sensitive to small distance changes, which means that breathing or other external body movements will change the phase but not the amplitude, thus providing good isolation from other signals within the body to be properly sensed. In the NCS, interference measurement-like structures convert organ/tissue movement into amplitude modulation of the RF signal.
對於吾人之模擬(圖2A)，當人體模型(human phantom)面向接收器時(圖4A)，胸部上天線發射RF載波，其中藉由局部近場區域界定天線特性。根據天線指向性，將朝向接收器直接發射RF能量之部分，而其他部分將歸因於近場效應而耦合於身體內部。直觀地，可考量藉由心臟組織之機械移動調變來自心臟之反向散射RF信號且接著使用直接發射進行干擾，從而導致振幅改變。從干擾計類比，身體內部之移動係一「差分模式」調變，而身體表面移動係一「共同模式」調變。 For our simulation (Figure 2A), when the human phantom is facing the receiver (Figure 4A), the antenna on the chest transmits an RF carrier, with the antenna characteristics defined by the local near-field region. Depending on the antenna directivity, part of the RF energy will be emitted directly toward the receiver, while other parts will be coupled inside the body due to near-field effects. Intuitively, one can consider modulating the backscattered RF signal from the heart by mechanical movement of cardiac tissue and then interfering with direct emission, resulting in amplitude changes. From the interference meter analogy, the movement inside the body is a "differential mode" modulation, while the movement on the surface of the body is a "common mode" modulation.
不僅可從遠場而且亦可從如圖3B中之散射參數S11展示之天線反射記錄運動。使用天線反射，一NCS信號可使用一行動裝置直接記錄且因此對身體移動及一擁擠房間內之室內多路徑問題更具免疫力。由於NCS運用天線之近場區域內之組織運動操作，故幾何變化將影響天線反射S11，其中天線可被視為感測器之一部分。生命徵象將調變在天線之S11參數上且因此藉由反射信號擷取。 Motion can be recorded not only from the far field but also from the antenna reflections as shown by the scattering parameter S11 in Figure 3B. Using antenna reflections, an NCS signal can be recorded directly using a mobile device and is therefore more immune to body movement and indoor multipath problems in a crowded room. Since NCS operates using tissue motion in the near-field region of the antenna, geometric changes will affect the antenna reflection S 11 , where the antenna can be considered as part of the sensor. The vital signs will be modulated on the S11 parameters of the antenna and thus captured by the reflected signal.
在傳輸天線接近於皮膚之情況下，一NCS裝置可透過一無 線電信號調變運動信號(生命徵象)。然而，習知微波傳輸器在局部振盪器及功率放大器中消耗顯著功率，且此等傳輸器可需要用於行動裝置之一電池。另外，身體上傳輸器與遠場接收器之間的同步亦將使系統設計更複雜。在一些實施例中，可使用被動諧波RF識別(RFID)標籤實施NCS，其中在諧波反向散射連同標籤ID上調變生命信號。除超低成本以外，被動標籤之簡單及穩健封裝亦實現與準備衣物之直接織物整合。在圖9A中展示與織物上之一刺繡天線整合之RFID感測器標籤晶片之一實例。在圖8A及圖8B中概述諧波反向散射優於習知RFID之益處。由於習知RFID讀取器及相位雜訊邊緣之高傳輸功率，來自非預期周圍物件之自洩漏、天線反射及反向散射皆促成雜訊且使反向散射標籤信號之SNR嚴重降級。然而，諧波反向散射可使用一大頻率分離來隔離下行鏈路(讀取器至標籤)與上行鏈路(標籤至讀取器)，此增大SNR及敏感度兩者。標籤仍為一被動反向散射器，其可容易地遵循當前RF協定。在圖5A中展示諧波標籤之一示意圖(印刷電路板(PCB)原型之一照片見圖9B)。諧波標籤從讀取器接收處於f之下行鏈路RF信號，該信號通過標籤天線1(ANT 1)且分成兩個部分。一個部分藉由能量採集而為標籤電路提供DC功率，且另一部分在2f下饋送至被動諧波產生中以從天線2(ANT 2)重新發射，天線2用作為NCS傳輸器。諧波產生器前方之RF開關可藉由開關鍵控(OOK)而調變數位資訊，類似於習知RFID操作。數位資訊可包含標籤ID以及來自標籤上感測器之額外資訊。 With the transmitting antenna close to the skin, an NCS device can Wire signals modulate motion signals (vital signs). However, conventional microwave transmitters consume significant power in local oscillators and power amplifiers, and these transmitters may require batteries for mobile devices. In addition, synchronization between the body transmitter and the far-field receiver will also make the system design more complex. In some embodiments, NCS can be implemented using passive harmonic RF identification (RFID) tags, where vital signals are modulated on harmonic backscatter along with the tag ID. In addition to ultra-low cost, the simple and robust packaging of passive tags also enables direct fabric integration into prepared garments. An example of an RFID sensor tag chip integrated with an embroidered antenna on fabric is shown in Figure 9A. The benefits of harmonic backscatter over conventional RFID are summarized in Figures 8A and 8B. Due to the high transmission power of conventional RFID readers and the edge of phase noise, self-leakage from unexpected surrounding objects, antenna reflections and backscatter all contribute to noise and severely degrade the SNR of the backscattered tag signal. However, harmonic backscatter can use a large frequency separation to isolate the downlink (reader to tag) and the uplink (tag to reader), which increases both SNR and sensitivity. The tag is still a passive backscatter, which easily complies with current RF protocols. A schematic diagram of a harmonic tag is shown in Figure 5A (a photo of a printed circuit board (PCB) prototype is shown in Figure 9B). The harmonic tag receives the downlink RF signal at f from the reader, which passes through tag antenna 1 (ANT 1) and is split into two parts. One part provides DC power to the tag circuitry by energy harvesting, and the other part is fed into passive harmonic generation at 2f for re-transmission from antenna 2 (ANT 2), which serves as the NCS transmitter. The RF switch in front of the harmonic generator can modulate digital information through on-off keying (OOK), similar to conventional RFID operation. The digital information can include the tag ID and additional information from sensors on the tag.
在圖5B中展示作為一同調收發器之一例示性諧波RFID讀取器之一示意圖。相同數位時脈(虛線)經饋送至處於f及2f之兩個頻率合成器中以進行處於2f之同調解調變。數位模組執行CDMA協定。從讀取器至 標籤之下行鏈路命令藉由數位轉類比轉換器(「DAC」)調變且接著藉由混頻器升頻轉換為處於f之載波。諧波標籤反向散射至處於2f之讀取器，f藉由處於2f之同調局部振盪器降頻轉換為基頻帶且藉由正交類比轉數位轉換器(「ADC」)取樣。使用一軟體定義無線電(SDR)進行一諧波讀取器之一測試實施例之硬體。 A schematic diagram of an exemplary harmonic RFID reader as a coherent transceiver is shown in Figure 5B. The same digital clock (dashed line) is fed into two frequency synthesizers at f and 2f for co-modulation modulation at 2f. The digital module implements the CDMA protocol. from reader to Downlink commands under the tag are modulated by a digital-to-analog converter ("DAC") and then upconverted by a mixer to a carrier at f. The harmonic tags are backscattered to the reader at 2f, which is downconverted to the baseband by a coherent local oscillator at 2f and sampled by a quadrature analog-to-digital converter ("ADC"). Hardware for one test embodiment of a harmonic reader using a Software Defined Radio (SDR).
相位對相對於讀取器之標籤實體位置更敏感。因此，當一標籤之天線2放置於一個體之胸部上時，可從正交方案中之相位導出呼吸資訊，如在圖6A中使用原始及低通濾波波形展示。基於反向散射相位資訊，可憑藉毫米解析度計算多個標籤之位置，其等可進一步導出呼吸運作。儘管由胸部移動導致之相位變化遠強於心跳及腕部脈搏之內部移動，但其係身體內部之組織運動之NCS之一「共同分量」(如上文進一步描述)。在使用本系統之實施例執行之實驗期間，NCS心跳信號對由個體之呼吸導致之移動具免疫力。多個頻率、改良信號處理及反射結構(圖12A及圖12B)之使用可進一步減輕嚴重多路徑干擾。首先，從瞬時週期(實線)及從10秒內之計數(虛線)擷取圖6B中之心率。從一商用血壓監測器(OMRON BP760N)量測星形標記。應注意，從正交解調變獨立地導出呼吸及心跳資訊，且無需如習知微波反向散射中之特殊濾波或圖案辨識。 Phase is more sensitive to the physical position of the tag relative to the reader. Therefore, when a tag's antenna 2 is placed on an individual's chest, breathing information can be derived from the phase in a quadrature scheme, as shown in Figure 6A using raw and low-pass filtered waveforms. Based on the backscattered phase information, the positions of multiple tags can be calculated with millimeter resolution, which can further derive breathing operations. Although the phase change caused by chest movement is much stronger than the internal movement of the heartbeat and wrist pulse, it is a "common component" of the NCS of tissue movement within the body (as further described above). During experiments performed using embodiments of the present system, the NCS heartbeat signal was immune to movement caused by the breathing of the subject. The use of multiple frequencies, improved signal processing, and reflective structures (Figures 12A and 12B) can further mitigate severe multipath interference. First, the heart rate in Figure 6B is captured from the instantaneous period (solid line) and from the count within 10 seconds (dashed line). Star marks were measured from a commercial blood pressure monitor (OMRON BP760N). It should be noted that respiration and heartbeat information are independently derived from quadrature demodulation and do not require special filtering or pattern recognition as is conventional in microwave backscatter.
由於從NCS擷取內部生命徵象，似干擾計結構(interferometer-like structure)顯著增大敏感度以實現運動波形之收集，類似於一心衝擊圖(「BCG」)。同時記錄來自胸部及腕部標籤之資料達3分鐘。使用PCB標籤進行試驗且讀取器天線距離受測試人員~1.5m至2m。藉由標籤轉換之諧波信號在1.9GHz(2f)下為約-20dBm。為分析波形 變化，疊置各週期以獲得如圖6C及圖6D中展示之心跳及腕部脈搏波形之平均值及盒鬚偏差。波形經正規化至記錄資料之第90個百分位數。應用動態時間扭曲(「DTW」)以分類波形以導出詳細特徵。圖6E及圖6F展示心臟及脈搏波形之DTW距離，且插圖展示變化。圖6G及圖6H展示所提取模板波形與最大距離波形及中值距離波形之比較，中值距離波形仍非常類似於模板且保持大部分主要特徵，諸如腕部脈搏中之反衝峰值。詳細運動波形分析可用作例如用於心律不整及主動脈瓣疾病之一心電圖候選。 Due to the capture of internal vital signs from the NCS, the interferometer-like structure significantly increases sensitivity to enable collection of motion waveforms, similar to a body-cardiogram ("BCG"). Record data from chest and wrist tags simultaneously for 3 minutes. The test was conducted using PCB tags and the reader antenna was ~1.5m to 2m away from the person being tested. The harmonic signal converted by the tag is about -20dBm at 1.9GHz (2f). To analyze waveforms changes, overlapping the cycles to obtain the mean and box-whisker deviation of the heartbeat and wrist pulse waveforms shown in Figures 6C and 6D. Waveforms were normalized to the 90th percentile of the recorded data. Apply dynamic time warping ("DTW") to classify waveforms to derive detailed features. Figures 6E and 6F show the DTW distance of the heart and pulse waveforms, and the insets show the changes. Figure 6G and Figure 6H show the comparison of the extracted template waveform with the maximum distance waveform and the median distance waveform. The median distance waveform is still very similar to the template and maintains most of the main features, such as the kickback peak in the wrist pulse. Detailed motion waveform analysis can be used, for example, as an electrocardiogram candidate for cardiac arrhythmias and aortic valve disease.
CDMA協定不僅能夠同時監測多個人員，而且亦能夠同時監測相同人員上之多個點。CDMA標籤之可允許數目受限於基頻帶資料率且在圖11中展示。來自不同身體位置之波形時序之比較透過脈波傳遞時間(「PTT」)提供血壓(「BP」)之估計，其可從近端動脈波形及遠端動脈波形之特徵點提取。提出之非接觸式血壓感測呈現優於基於直接壓力之方法之顯著優勢，基於直接壓力之方法尤其針對年老患者之長期監測導致不適性且破壞晝夜節律。記錄胸部標籤信號(近端波形)及左腕標籤信號(遠端波形)之各者達三分鐘，如圖7A中展示。可從兩個波形之主峰容易地提取PTT。插圖展示一特定週期之詳細波形。圖7B展示PTT在3分鐘記錄期間的概率密度。PTT之分佈會受到取樣抖動及波形失真影響。可針對各心跳獲得一個PTT取樣，且可容易地應用移動平均值或其他信號處理方法以使PTT變化最小化。圖7C及圖7D展示從PTT計算之血壓以及來自商用血壓監測器(OMRON BP760N)之比較點(星形標記)。實線係每一心跳之收縮壓及舒張壓。虛線係來自約10秒之取樣點之移動平均值。圖7C中之資料係在受測試人員坐在一椅子上約30分鐘時收集，而圖7D中之資料係在一適度活動之後收集。 The CDMA protocol can not only monitor multiple persons at the same time, but also monitor multiple points on the same person at the same time. The allowable number of CDMA tags is limited by the baseband data rate and is shown in Figure 11. Comparison of waveform timings from different body locations provides an estimate of blood pressure ("BP") via pulse transit time ("PTT"), which can be extracted from feature points of the proximal and distal arterial waveforms. The proposed non-contact blood pressure sensing presents significant advantages over direct pressure-based methods, which cause discomfort and disrupt circadian rhythms especially for long-term monitoring of elderly patients. Record each of the chest tag signal (proximal waveform) and left wrist tag signal (distal waveform) for three minutes, as shown in Figure 7A. PTT can be easily extracted from the main peak of the two waveforms. The illustration shows the detailed waveform of a specific period. Figure 7B shows the probability density of PTT during the 3-minute recording period. The distribution of PTT will be affected by sampling jitter and waveform distortion. One PTT sample can be obtained for each beat, and moving averages or other signal processing methods can easily be applied to minimize PTT variations. Figures 7C and 7D show blood pressure calculated from PTT and comparison points (star marks) from a commercial blood pressure monitor (OMRON BP760N). The solid lines represent the systolic and diastolic blood pressure for each heartbeat. The dashed line is the moving average from approximately 10 seconds of sampling points. The data in Figure 7C were collected while the subject was sitting in a chair for approximately 30 minutes, while the data in Figure 7D were collected after a moderate activity.
使用CST Microwave Studio進行電磁模擬。Zubal Phantom用於建構介電模型。使用來自電腦斷層掃描(CT)及磁共振成像(MRI)之資料校準組織幾何資訊。立體像素之解析度係3.6mm×3.6mm×3.6mm。使用CST生物庫映射各種組織之微波性質。首先逐層將Zubal Phantom資料預處理為組織幾何座標連同組織指數之檔案結構。CST接著匯入檔案且使用三維座標及組織性質自動建立每一立體像素，以建立藉由CST內建Visual Basic for Applications(VBA)巨集語言之描述性語言控制之介電模型。程序類似於三維印刷，但實際上僅在CST軟體中進行。心跳及腕部脈搏之動態模擬藉由幾何變化實現，其中心臟及腕部血管之幾何性質根據用作為實況之預設尺寸而變化。 Electromagnetic simulations were performed using CST Microwave Studio. Zubal Phantom is used to construct dielectric models. Tissue geometry information is calibrated using data from computed tomography (CT) and magnetic resonance imaging (MRI). The resolution of the stereo pixel is 3.6mm×3.6mm×3.6mm. Mapping the microwave properties of various tissues using the CST biobank. First, the Zubal Phantom data is preprocessed layer by layer into a file structure of tissue geometric coordinates and tissue index. CST then imports the file and automatically creates each voxel using 3D coordinates and tissue properties to create a dielectric model controlled by the descriptive language of CST's built-in Visual Basic for Applications (VBA) macro language. The procedure is similar to 3D printing, but is actually performed only in CST software. Dynamic simulation of the heartbeat and wrist pulse is achieved through geometric changes, where the geometric properties of the heart and wrist blood vessels change according to the preset dimensions used as reality.
藉由一自訂PCB原型化被動諧波反向散射標籤，從無線識別及感測平台(WISP)修改該自訂PCB。標籤上之諧波產生器經設計有一非線性傳輸線(NLTL)，其包含電感器及變容器之一梯形結構。NLTL可提供具有低輸入功率之高轉換效率，此對於被動反向散射標籤設計係必要的。諧波RFID讀取器及天線反射系統經建立於國家儀器Ettus軟體定義無線電(SDR)B210之平台上。為實現同調諧波解調變，接收器之局部振盪器(LO)需要直接從傳輸器LO之第二諧波頻率予以導出。用LabVIEW撰寫即時控制及解調變軟體。運用零差調變方案，操作頻率係f=950MHz(處於2f之二次諧波=1.9GHz)。下行鏈路類比基頻帶係10kHz且諧波轉換之後的上行鏈路類比基頻帶係20kHz。數位轉類比轉換及類比轉數位轉換兩者皆按每秒106個樣本(Sps)而操作。原始數位信號接著經濾波、數位地降頻轉換為D.C.頻帶、且使用CDMA演算法解碼以區分來自各標籤之資 訊。接著藉由500Sps之取樣率減少取樣來自各標籤之信號。藉由具有0.8Hz之一截止頻率之一低通濾波器處理呼吸信號。藉由介於0.9Hz與15Hz之間的帶通濾波器處理心跳及脈搏信號。被動標籤之當前操作範圍係~1.5m，受限於WISP平台。範圍可根據習知RFID系統在相同頻帶中之操作而延伸朝向10m。 By prototyping a custom PCB with passive harmonic backscatter tags, modify the custom PCB from the Wireless Identification and Sensing Platform (WISP). The harmonic generator on the tag is designed with a non-linear transmission line (NLTL), which contains a ladder structure of inductors and varactor. NLTL can provide high conversion efficiency with low input power, which is necessary for passive backscatter tag design. The harmonic RFID reader and antenna reflection system is built on the National Instruments Ettus software-defined radio (SDR) B210 platform. To achieve co-harmonic demodulation, the receiver's local oscillator (LO) needs to be derived directly from the second harmonic frequency of the transmitter LO. Use LabVIEW to write real-time control and demodulation software. Using homodyne modulation scheme, the operating frequency is f=950MHz (at the second harmonic of 2f=1.9GHz). The downlink analog baseband is 10 kHz and the uplink analog base band after harmonic conversion is 20 kHz. Both digital-to-analog conversion and analog-to-digital conversion operate at 106 samples per second (Sps). The raw digital signal is then filtered, digitally down-converted to the D.C. band, and decoded using a CDMA algorithm to distinguish the data from each tag. news. The signal from each tag is then reduced by sampling at a sampling rate of 500Sps. The respiratory signal is processed by a low-pass filter with a cutoff frequency of 0.8 Hz. Heartbeat and pulse signals are processed through a band-pass filter between 0.9Hz and 15Hz. The current operating range of passive tags is ~1.5m, which is limited by the WISP platform. The range may extend towards 10m in accordance with the operation of conventional RFID systems in the same frequency band.
在另一模擬中，在接近於其中可感受脈搏之心臟及左腕處部署天線。信號源應在天線之近場區內，但無需藉由天線進行直接皮膚接觸。圖2A展示簡化下臂結構及CST Microwave Studio中之近場區域中之電場。天線經組態以將更多能量耦合至組織中以獲得較大信雜比(「SNR」)。在圖2B中展示天線反射參數S11。中心頻率係約1.85GHz。由於高組織電容率，天線頻寬更寬。圖2A中之模擬結果展示耦合至皮膚層、脂肪層及肌肉層以及附近血管中之電場。 In another simulation, antennas were deployed close to the heart and left wrist where the pulse could be felt. The signal source should be within the near field of the antenna, but no direct skin contact via the antenna is required. Figure 2A shows the simplified lower arm structure and the electric field in the near field region in CST Microwave Studio. The antenna is configured to couple more energy into the tissue for a greater signal-to-noise ratio ("SNR"). The antenna reflection parameter S 11 is shown in Figure 2B. The center frequency is about 1.85GHz. The antenna bandwidth is wider due to high tissue permittivity. The simulation results in Figure 2A show the electric fields coupled to the skin, fat and muscle layers and nearby blood vessels.
為模擬耦合至EM場上之機械運動，將一小振動引入至心臟及腕部血管之幾何標度中，且組織模型中之血管橫剖面在t1、t2及t3之時間戳記中準靜態地變化以表示脈搏變化。在圖3A及圖3B中使用粗實線展示正規化振動振幅。圖4A及圖4B展示在CST Microwave Studio中模擬之遠場場型。陰影斜坡指示相位，而形狀表示共極化電場之振幅輪廓。記錄且在圖3A中展示遠場信號(其中取樣點在胸部(圖4A)前方及腕部(圖4B)上方1m)。可見，解調變心臟信號(在圖3A中使用一虛線描繪)及腕部脈搏信號(使用一點劃線描繪)與已知振動良好地匹配。 To simulate mechanical motion coupled to the EM field, a small vibration is introduced into the geometric scale of the heart and wrist vessels, and the vessel cross-section in the tissue model changes quasi-statically at the time stamps of t1, t2, and t3 to indicate changes in pulse. The normalized vibration amplitude is shown using thick solid lines in FIGS. 3A and 3B . Figure 4A and Figure 4B show the far field pattern simulated in CST Microwave Studio. The shaded slope indicates the phase, while the shape represents the amplitude profile of the copolarized electric field. The far-field signal was recorded and shown in Figure 3A (where the sampling point was in front of the chest (Figure 4A) and 1 m above the wrist (Figure 4B)). It can be seen that the demodulated heart signal (depicted by a dotted line in Figure 3A) and the wrist pulse signal (depicted by a dotted line) match well with the known vibrations.
遠場可被視為兩個近場分量之干擾結果：來自天線之直接傳播波(圖2A之黑色箭頭)及來自內部組織之散射信號(白色箭頭)。當一心跳導致血管振動時，將歸因於干擾直接傳播而調變散射信號之相位。由於 從差分干擾導出解調變血管運動信號，故由呼吸或其他身體移動導致之天線運動可視為可被拒絕之共同模式。替代地，散射信號可耦合回至相同天線以進行同調解調變，此經指示為圖2A中之灰色箭頭及圖2B中之所得S11。 The far field can be viewed as the result of interference from two near-field components: the directly propagating wave from the antenna (black arrow in Figure 2A) and the scattered signal from the internal tissue (white arrow). When a heartbeat causes blood vessels to vibrate, the phase of the scattered signal is modulated due to direct propagation of the interference. Since the demodulated vasomotion signal is derived from differential interference, antenna motion due to breathing or other body movements can be considered a common pattern that can be rejected. Alternatively, the scattered signal can be coupled back to the same antenna for coherent modulation, which is indicated by the gray arrow in Figure 2A and the resulting S11 in Figure 2B.
圖2A繪示如何使來自天線之EM場能量之一部分直接輻射至遠場(如由黑色箭頭指示)而EM能量之其他部分耦合至多層組織中直至感測目標(此處係動脈血管)。由於介電常數差異，來自脈搏之動脈血管之機械運動將調變反向散射信號，由白色箭頭指示。此信號亦連同直接輻射信號一起傳播至遠場。從EM場之觀點而言，此兩個信號源自相同源但通過不同路徑，即，此兩個信號係同調的且組合信號之振幅將歸因於相位差異而改變。可因此明白血管之機械運動將如何導致振幅調變。此操作原理類似於干擾計，且近場調變可被視為干擾計類比中之「差分分量」。另一方面，表面或整個身體之移動(諸如呼吸及身體運動)將同時改變兩個信號路徑之相位，此可被視為干擾計結構中之「共同模式」。因此，NCS不僅利用干擾計結構之敏感度以增強效能，而且亦隔離兩個不同調變：來自具有近場耦合之身體內部之一個調變及來自具有直接發射之表面運動之另一調變。 Figure 2A illustrates how a portion of the EM field energy from the antenna is radiated directly into the far field (as indicated by the black arrow) while the other portion of the EM energy is coupled into multiple layers of tissue up to the sensing target (here an artery). Due to dielectric constant differences, the mechanical movement of the arterial vessels from the pulse will modulate the backscattered signal, indicated by the white arrows. This signal also propagates to the far field along with the directly radiated signal. From an EM field point of view, these two signals originate from the same source but take different paths, ie, the two signals are coherent and the amplitude of the combined signal will change due to the phase difference. It can be understood how the mechanical movement of blood vessels will lead to amplitude modulation. The principle of operation is similar to that of an interferometer, and near-field modulation can be considered the "differential component" in the interferometer analogy. On the other hand, movement of the surface or the entire body (such as breathing and body movements) will simultaneously change the phase of both signal paths, which can be considered a "common pattern" in the interference meter structure. Therefore, NCS not only exploits the sensitivity of the interferometer structure to enhance performance, but also isolates two different modulations: one modulation from inside the body with near-field coupling and another modulation from surface motion with direct emission.
在一例示性實施例中，可藉由被動諧波RF識別(RFID)標籤實施NCS，其中在諧波反向散射連同標籤ID上調變生命徵象信號。除超低成本以外，此一被動標籤實施例之簡單及穩健封裝亦實現與準備衣物之直接織物整合。使用Ettus ResearchTM軟體定義無線電(「SDR」)B210平台建立一例示性諧波RFID讀取器及天線反射系統。 In an exemplary embodiment, NCS may be implemented with passive harmonic RF identification (RFID) tags, where vital sign signals are modulated on harmonic backscatter along with the tag ID. In addition to being ultra-low cost, the simple and robust packaging of this passive tag embodiment also enables direct fabric integration into garment preparations. An exemplary harmonic RFID reader and antenna reflector system was built using the Ettus Research TM Software Defined Radio ("SDR") B210 platform.
在圖5A中展示一例示性諧波標籤之一示意圖，且圖9B係此一標籤之一PCB原型之一照片。為易於協定存取，在圖8B中基於無線識別及感測平台(「WISP」)對諧波標籤之PCB原型執行所有例示性NCS操作。原型RFID感測器標籤晶片與織物上之一刺繡天線整合(圖9A中展示)。織物RFID標籤用於示範本發明揭示方法之服裝整合之可行性。根據電子生產碼(「EPC」)協定驗證標籤ID及溫度感測之正常RFID資料異動。 A schematic diagram of an exemplary harmonic tag is shown in Figure 5A, and Figure 9B is a photograph of a PCB prototype of such a tag. To facilitate protocol access, all exemplary NCS operations are performed on the PCB prototype of the harmonic tag based on the Wireless Identification and Sensing Platform ("WISP") in Figure 8B. The prototype RFID sensor tag chip is integrated with an embroidered antenna on the fabric (shown in Figure 9A). Fabric RFID tags are used to demonstrate the feasibility of garment integration of the disclosed method. Verify normal RFID data changes of tag ID and temperature sensing according to the Electronic Production Code ("EPC") protocol.
用LabVIEW撰寫即時解調變軟體。運用零差調變方案，操作頻率係f=950MHz(處於2f之二次諧波=1.9GHz)。下行鏈路類比基頻帶係10kHz且諧波轉換之後的上行鏈路類比基頻帶係20kHz。數位轉類比轉換及類比轉數位轉換兩者皆按每秒106個樣本(Sps)而操作。所提出之被動標籤操作範圍係約1.5m，受限於WISP平台。範圍可根據習知RFID系統在相同頻帶中之操作而延伸朝向10m。 Use LabVIEW to write real-time demodulation software. Using homodyne modulation scheme, the operating frequency is f=950MHz (at the second harmonic of 2f=1.9GHz). The downlink analog baseband is 10 kHz and the uplink analog base band after harmonic conversion is 20 kHz. Both digital-to-analog conversion and analog-to-digital conversion operate at 10 6 samples per second (Sps). The proposed passive tag operating range is about 1.5m, which is limited by the WISP platform. The range may extend towards 10m in accordance with the operation of conventional RFID systems in the same frequency band.
在圖8B中展示諧波RFID反向散射之原理。在一實施例中，一讀取器傳輸處於基本頻率f之一下行鏈路信號，其將供電給讀取器之一範圍內之任何諧波標籤。諧波標籤從讀取器接收處於f之下行鏈路RF信號，該下行鏈路信號通過標籤天線1且分成兩個部分：一個部分用於能量採集以提供DC功率給標籤電路，且另一部分經饋送至處於2f之被動諧波產生中以從天線2作為上行鏈路載波重新發射以消除讀取器自干擾及來自附近物件之反射。以此方式，天線2用作為NCS傳輸器。傳輸器(Tx)處之一低通濾波器(「LPF」)及接收器(Rx)處之一高通濾波器(「HPF」)進一步隔離處於f及2f之兩個載波。運用同調諧波反向散射，Rx具有一非常低雜訊底限。因此，可增大Rx敏感度，此使系統能夠區分在上行鏈路上 調變之弱生命信號。諧波產生器(圖5A)前方之一RF開關可藉由開關鍵控(「OOK」)而調變數位資訊，類似於習知RFID操作。數位資訊可包含標籤ID以及來自標籤上感測器之額外資訊。 The principle of harmonic RFID backscattering is shown in Figure 8B. In one embodiment, a reader transmits a downlink signal at the fundamental frequency f, which will power any harmonic tag within a range of the reader. The harmonic tag receives a downlink RF signal at f from the reader, which passes through the tag antenna 1 and is divided into two parts: one part is used for energy harvesting to provide DC power to the tag circuit, and the other part is Feed into passive harmonic generation at 2f for retransmission from antenna 2 as an uplink carrier to eliminate reader self-interference and reflections from nearby objects. In this way, antenna 2 acts as an NCS transmitter. A low pass filter ("LPF") at the transmitter (Tx) and a high pass filter ("HPF") at the receiver (Rx) further isolate the two carriers at f and 2f. Using coherent harmonic backscatter, Rx has a very low noise floor. Therefore, the Rx sensitivity can be increased, which enables the system to distinguish between Modulation of weak life signals. An RF switch in front of the harmonic generator (Figure 5A) can modulate digital information through on-off keying ("OOK"), similar to conventional RFID operation. The digital information can include the tag ID and additional information from sensors on the tag.
可透過使用諸如例如分碼多重存取(「CDMA」)協定之一協定而實現多標籤存取。此一協定之使用可提供諧波反向散射中之較佳標籤間同步、較高頻道效率及較高功率效率。CDMA標籤之可允許數目受限於基頻帶資料率且在圖11中展示。實線係CDMA碼，其中晶片碼長度與標籤數目成線性比例。然而，當數目變大時，半正交碼長度可近似對數，展示為虛線。為復原波形細節，取樣率應高於500Hz，此可在具有CDMA之諧波反向散射系統之例示性實施例中容易地實現。 Multi-label access may be achieved through the use of a protocol such as, for example, the Code Division Multiple Access ("CDMA") protocol. The use of this protocol can provide better inter-tag synchronization, higher channel efficiency and higher power efficiency in harmonic backscatter. The allowable number of CDMA tags is limited by the baseband data rate and is shown in Figure 11. The solid line is a CDMA code, where the chip code length is linearly proportional to the number of tags. However, when the number becomes large, the semi-orthogonal code length can be approximately logarithmic, shown as a dashed line. To recover waveform details, the sampling rate should be higher than 500 Hz, which can be easily accomplished in the exemplary embodiment of a harmonic backscatter system with CDMA.
藉由額外路徑且因此相關機械移動(此處係動脈及靜脈脈搏)調變反向散射信號之相位。在遠場處，兩個部分如一干擾計般彼此干擾，即，腕部脈搏將調變接收器處之EM波之振幅。同時，外部移動(諸如例如擺手)調變兩個部分之相位且將導致兩個信號之共同調變。簡言之，手部運動將為共同模式且腕部脈搏將為差分模式。圖1A展示部署於胸部區域附近以監測心跳之感測天線。歸因於近場效應，EM場耦合至身軀中，且藉由心跳調變反向散射信號。藉由遠場處之接收器接收直接傳輸及反向散射信號。兩個部分係來自相同源且具有不同路徑，且其等將彼此干擾，其中心跳可從振幅解調變。由呼吸導致之胸部移動改變兩個信號之相位，此係NCS之共同模式。類似於腕部標籤中之手部運動情況，呼吸及心跳信號歸因於與後者濾波無關之共同及差分模式而良好地隔離。 The phase of the backscattered signal is modulated by the additional paths and therefore the associated mechanical movements (here arterial and venous pulses). In the far field, the two parts interfere with each other like an interference meter, i.e., the wrist pulse will modulate the amplitude of the EM wave at the receiver. At the same time, external movement (such as eg hand waving) modulates the phase of both parts and will result in co-modulation of both signals. In short, the hand movement will be a common pattern and the wrist pulse will be a differential pattern. Figure 1A shows a sensing antenna deployed near the chest area to monitor heartbeat. Due to the near-field effect, EM fields couple into the body and backscatter signals modulated by the heartbeat. Direct transmission and backscattered signals are received by a receiver in the far field. The two parts come from the same source and have different paths, and they will interfere with each other, where the heartbeat can vary from amplitude demodulation. Chest movement caused by breathing changes the phase of the two signals, a common pattern in NCS. Similar to the hand movement case in the wrist tag, the respiratory and heartbeat signals are well isolated due to common and differential modes that are independent of the latter's filtering.
為將NCS實施為室內環境中之一穿戴式裝置，使用具有分碼多重存取(CDMA)協定之一例示性諧波RFID系統。在圖8B中展示RF示 意圖。讀取器傳輸處於頻率f之下行鏈路(讀取器至標籤)信號。諧波標籤接收下行鏈路信號且將處於2f之二次諧波反向散射為上行鏈路(標籤至讀取器)信號。傳輸器(Tx)及接收器(Rx)頻譜經分離以增大信雜比(SNR)及接收器敏感度。CDMA協定提供更佳標籤同步、較高取樣率、較低抖動及較低功率消耗。在圖22A中展示諧波標籤之示意圖。天線1(ANT 1)接收下行鏈路RF信號，其中標籤採集RF能量、供電給邏輯電路且解調變下行鏈路資訊。下行鏈路RF信號之部分耦合至非線性傳輸線(NLTL)以產生二次諧波信號，藉由RF開關調變該二次諧波且透過天線2(ANT 2)傳輸回至讀取器。反向散射二次諧波信號執行NCS功能且接著被讀取器之Rx天線接收。在圖22B中展示用於以下實驗之PCB原型，其具有約57×20mm之尺寸。標籤可經進一步整合為一被動晶片且使用服裝直接封裝，其中天線可由圖30中之導電油墨及由圖9A中之刺繡實施。 To implement NCS as a wearable device in an indoor environment, an exemplary harmonic RFID system with code division multiple access (CDMA) protocol is used. The RF schematic is shown in FIG8B . The reader transmits a downlink (reader to tag) signal at frequency f. The harmonic tag receives the downlink signal and backscatters the secondary harmonic at 2f as an uplink (tag to reader) signal. The transmitter (Tx) and receiver (Rx) spectrum are separated to increase the signal-to-noise ratio (SNR) and receiver sensitivity. The CDMA protocol provides better tag synchronization, higher sampling rate, lower jitter and lower power consumption. A schematic diagram of a harmonic tag is shown in FIG22A . Antenna 1 (ANT 1) receives the downlink RF signal, where the tag collects RF energy, powers the logic circuit and demodulates the downlink information. Part of the downlink RF signal is coupled to the nonlinear transmission line (NLTL) to generate a secondary harmonic signal, which is modulated by the RF switch and transmitted back to the reader through antenna 2 (ANT 2). The backscattered secondary harmonic signal performs the NCS function and is then received by the Rx antenna of the reader. The PCB prototype used for the following experiments is shown in Figure 22B, which has a size of approximately 57×20mm. The tag can be further integrated into a passive chip and directly packaged using clothing, where the antenna can be implemented by the conductive ink in Figure 30 and by the embroidery in Figure 9A.
圖10展示在結合CDMA協定應用基於相位之諧波反向散射定位方法時之標籤定位誤差。模擬結果展示各種SNR下之定位誤差之累積概率函數。由於在諧波反向散射系統中已消除自干擾及直接反射，故雜訊底限可非常低以容易地達成20dB之SNR。 Figure 10 shows the tag positioning error when applying the phase-based harmonic backscattering positioning method in conjunction with the CDMA protocol. The simulation results show the cumulative probability function of positioning error under various SNRs. Since self-interference and direct reflections are eliminated in harmonic backscatter systems, the noise floor can be very low and an SNR of 20dB can be easily achieved.
在圖12A中展示實驗天線反射系統且在圖12B中展示經量測心跳波形。圖12A中之示意圖可由安裝於心臟附近之服裝上之一主動標籤實現，其中標籤天線執行NCS功能。對於直接比較，一諧波產生器及一諧波收發器經選擇為類似於圖5A及圖5B之被動標籤系統以建立天線反射單元。可使用其他設計，包含例如在一單一頻率中使用高隔離度循環器。實驗系統中使用之信號分離器及諧波產生器兩者皆為雙向的。來自處於f之Tx之信號耦合至諧波產生器且接著耦合至處於f及2f兩者之天線。天線 反射再次饋送通過諧波產生器及分離器，但僅約2f之信號被帶通濾波器(「BPF」)選擇用以饋送回至Rx以進行同調解調變。對超過2f之生命信號取樣且以完全數位格式發送至遠端裝置，其中可藉由具有低資料率之標準技術容易地消除由多路徑及占有人運動導致之室內符號間干擾。圖12B展示解調變心跳信號(應用0.9Hz至15Hz濾波器)，正規化至資料之90百分位數。運用天線反射方案，藉由NCS偵測到之生命信號對由周圍移動導致之嚴重多路徑干擾(諸如一擁擠房間之情況)更具免疫力。 The experimental antenna reflection system is shown in Figure 12A and the measured heartbeat waveform is shown in Figure 12B. The schematic diagram in Figure 12A can be realized by an active tag mounted on the garment near the heart, where the tag antenna performs the NCS function. For direct comparison, a harmonic generator and a harmonic transceiver were selected similar to the passive tag system of Figures 5A and 5B to create the antenna reflection unit. Other designs may be used, including, for example, using a high isolation circulator at a single frequency. Both the signal splitter and the harmonic generator used in the experimental system are bidirectional. The signal from Tx at f couples to the harmonic generator and then to the antennas at both f and 2f. antenna The reflections are again fed through the harmonic generator and splitter, but only about 2f of the signal is selected by the bandpass filter ("BPF") to be fed back to Rx for coherent demodulation. More than 2f of vital signals are sampled and sent to a remote device in a fully digital format, where indoor inter-symbol interference caused by multipath and occupant motion can be easily eliminated by standard techniques with low data rates. Figure 12B shows the demodulated heartbeat signal (0.9Hz to 15Hz filter applied), normalized to the 90th percentile of the data. Using the antenna reflection scheme, the vital signals detected by NCS are more immune to severe multipath interference caused by surrounding movement (such as the situation in a crowded room).
作為無需直接機械接觸之NCS操作之一獨立驗證程序，使用具有已知旋轉速率之一非對稱軸馬達(ASLONG JGB37-520)(圖13)。被動標籤之天線經放置接近於非對稱旋轉軸，且透過相位調變及解調變將機械旋轉轉換為一正弦波。 As an independent verification procedure of NCS operation without direct mechanical contact, an asymmetric shaft motor (ASLONG JGB37-520) with a known rotation rate was used (Fig. 13). The antenna of the passive tag is placed close to the asymmetric rotation axis, and the mechanical rotation is converted into a sine wave through phase modulation and demodulation.
在另一實驗中，將根據本發明之一實施例之一第一標籤(標籤1)放置於具有一已知旋轉之一已知馬達外部，且將一第二標籤(標籤2)放置於受測試之一個體之襯衫外部之心臟區域內。在圖15中展示來自馬達(標籤1)之所收集波形，其用作為驗證或校準。在圖16中展示來自胸部(標籤2)之所收集波形。在應用介於1.4Hz至15Hz之間的一簡單帶通濾波器之後，獲得圖17中之心臟運動波形。在圖18中放大約三秒之一特定波形，其中藉由包含特性點A至F而擷取主要運動特徵。例如，點C指示主要收縮運動，且點E指示閉合主動脈瓣之後的衝擊波反衝。 In another experiment, a first tag (Tag 1) according to an embodiment of the present invention was placed outside a known motor with a known rotation, and a second tag (Tag 2) was placed outside the subject. Inside the heart area on the outside of one of the test subjects' shirts. The collected waveforms from the motor (label 1) are shown in Figure 15 and are used for verification or calibration. The collected waveforms from the chest (label 2) are shown in Figure 16. After applying a simple bandpass filter between 1.4Hz and 15Hz, the heart motion waveform in Figure 17 is obtained. In Figure 18, a specific waveform is zoomed in for about three seconds, in which the main motion features are captured by including characteristic points A to F. For example, point C indicates the primary systolic motion, and point E indicates the shock wave recoil following closure of the aortic valve.
在另一實驗中，標籤1放置於胸部區域附近且標籤2在相同人員之腕部附近，且在圖19中展示所得經濾波波形。在圖20中放大約三秒之片段，其中兩個波形之主峰(點C)之時間延遲可用於使用已知技術給出血壓之一估計。峰1與峰2之間存在35個取樣點，且時間間隔係約0.074 秒且具有470Hz之一取樣率，從而導致約88mmHg之一舒張壓。對所判定血壓估計(例如在每一心跳處獲得)取平均可改良估計之可靠性。 In another experiment, Tag 1 was placed near the chest area and Tag 2 was placed near the wrist of the same person, and the resulting filtered waveforms are shown in Figure 19. In Figure 20, a segment of approximately three seconds is shown in which the time delay between the main peaks of the two waveforms (point C) can be used to give an estimate of blood pressure using known techniques. There are 35 sampling points between peak 1 and peak 2, and the time interval is about 0.074 seconds and has a sampling rate of 470Hz, resulting in a diastolic blood pressure of approximately 88mmHg. Averaging determined blood pressure estimates (eg, obtained at each beat) may improve the reliability of the estimate.
生命徵象(包含心率、血壓、呼吸率及呼吸運作)之連續監測對於eHealth係關鍵的。先前方法受限於精確性、便利性及感測能力。一些方法(諸如心電圖(ECG))歸因於直接皮膚接觸(其使穿戴者不舒適、限制身體運動且破壞晝夜節律)之要求而難以用於長期應用。同時，心跳間時序特徵對於健康監測及人類情感研究係重要的。 Continuous monitoring of vital signs (including heart rate, blood pressure, respiration rate and breathing operation) is critical to eHealth. Previous methods were limited by accuracy, convenience and sensing capabilities. Some methods, such as electrocardiography (ECG), are difficult to use for long-term applications due to the requirement for direct skin contact, which makes the wearer uncomfortable, restricts body movement, and disrupts circadian rhythms. At the same time, the timing characteristics between heartbeats are important for health monitoring and human emotion research.
對於現有系統，心電圖(ECG)係用於心跳監測之最流行方法，其使用身體電極以透過由心跳感應之小皮膚電流而聚集身體電位。為達成良好信號品質，電極需要藉由不適導電膠及脫毛而進行直接皮膚接觸。為進一步減少雜訊，需要具有不可極化Ag/AgCl之大電極。再者，當頻繁脫毛在動物測試中係不切實際時，***皮下電極，此不僅造成額外量測困難而且亦造成感染顧慮。感染可改變體內環境恆定條件，此可使生命徵象量測產生嚴重偏差。光學體積掃描(PPG)廣泛用於醫烷及穿戴式裝置兩者中之脈搏率。PPG利用氧合血紅素位準之光學吸收之週期性改變以調變半導體雷射之強度，且需要繁重處理其信號以在詳細資訊經常丟失時擷取清晰血管脈搏波形。此外，如受限於雷射穿透深度，心率及心率可變性(HRV)之精確量測仍具挑戰性，且甚至相對於雷射束之小相對身體移動導致嚴重偏差。聲學方法(諸如基於聽診器之心音圖(PCG)及基於超音波之心回波圖)具有類似問題。轉換器大小破壞舒適性且限制穿戴式方法之連續監測。組織中之聲波之失真儘管可由體脂肪相依後處理補償，但亦使信號品質降級。通常藉由壓力或應變計量測諸如呼吸率/運作及血壓之其 他生命徵象，但來自腕帶或袖口之不適性阻礙長期使用。 For existing systems, electrocardiography (ECG) is the most popular method for heartbeat monitoring, which uses body electrodes to gather body potentials through small skin currents induced by the heartbeat. In order to achieve good signal quality, the electrodes need to be in direct skin contact through uncomfortable conductive glue and hair removal. To further reduce noise, large electrodes with non-polarizable Ag/AgCl are required. Furthermore, when frequent hair removal is impractical in animal testing, subcutaneous electrodes are inserted, which not only causes additional measurement difficulties but also raises infection concerns. Infections can alter the constant conditions of the internal environment, which can severely bias vital sign measurements. Optical volumetric scanning (PPG) is widely used to measure pulse rate in both medical and wearable devices. PPG utilizes periodic changes in the optical absorption of oxygenated heme levels to modulate the intensity of semiconductor lasers, and requires heavy processing of its signals to capture clear vascular pulse waveforms when detailed information is often lost. Furthermore, accurate measurement of heart rate and heart rate variability (HRV) remains challenging due to limited laser penetration depth, and even small relative body movements relative to the laser beam lead to serious biases. Acoustic methods such as stethoscope-based phonocardiography (PCG) and ultrasound-based echocardiography have similar problems. The size of the transducer destroys comfort and limits continuous monitoring of wearable methods. Acoustic distortion in tissue, although compensated by body fat-dependent post-processing, also degrades signal quality. Other measurements such as respiratory rate/function and blood pressure are usually measured by pressure or strain gauges. Other vital signs are present, but discomfort from the wristband or cuff prevents long-term use.
一習知RF方法將一RF射束照射至胸部區域，且藉由身體表面反向散射遠場電磁(EM)波。在藉由接收器偵測之EM波上調變呼吸及心跳信號。遠場處之感測導致一些缺點：(1)空氣與人體組織之間的介電常數差異導致皮膚表面上之強反射，此意謂呼吸信號遠強於來自身體內部之信號。強呼吸信號可超過心跳信號，心跳信號之信雜比(SNR)及波形細節可歸因於有限量之能量及小幾何平均值而嚴重降級。(2)習知方法通常缺乏多頻道或多點感測，此限制其實際適用性。(3)從RF轉換器觀點而言，傳輸及接收頻帶彼此重疊，其中自干擾可使系統效能劣化。歸因於上述問題，習知RF生命徵象感測系統難以精確量測心跳波形或時間間隔。 One known RF method irradiates an RF beam to the chest area and backscatters far-field electromagnetic (EM) waves through the body surface. Respiration and heartbeat signals are modulated on the EM waves detected by the receiver. Sensing in the far field leads to some disadvantages: (1) The difference in dielectric constant between air and human tissue results in strong reflection on the surface of the skin, which means that the respiratory signal is much stronger than the signal from inside the body. Strong respiratory signals can exceed heartbeat signals, and the signal-to-noise ratio (SNR) and waveform details of the heartbeat signal can be severely degraded due to the limited amount of energy and small geometric mean. (2) Conventional methods usually lack multi-channel or multi-point sensing, which limits their practical applicability. (3) From the RF converter point of view, the transmission and reception frequency bands overlap with each other, and self-interference can degrade system performance. Due to the above problems, it is difficult for conventional RF vital sign sensing systems to accurately measure heartbeat waveforms or time intervals.
相比之下，本發明揭示之NCS方法將RF近場範圍內之身體表面上及皮膚組織下方之機械運動調變至具有唯一數位識別(ID)之多工諧波RFID(RF識別)反向散射信號上。在NCS中，呼吸信號與具有與跳動心臟耦合之較高RF能量之心跳信號良好地隔離。Tx及Rx信號藉由諧波反向散射而廣泛分離，此改良SNR且提供標籤ID之多工。憑藉心跳之此改良信號品質以及高頻分量之進一步頻譜等化以減少取樣抖動，可以可靠地量測精確心跳時間間隔。 In contrast, the disclosed NCS method modulates mechanical motion on the surface of the body and beneath skin tissue within the RF near field range to a polyharmonic RFID (RF Identification) inverse with a unique digital identification (ID). on the scattered signal. In NCS, the respiratory signal is well isolated from the heartbeat signal which has higher RF energy coupled to the beating heart. Tx and Rx signals are widely separated by harmonic backscatter, which improves SNR and provides tag ID multiplexing. With this improved signal quality of heartbeats and further spectral equalization of high frequency components to reduce sampling jitter, precise heartbeat time intervals can be reliably measured.
為針對心跳實驗性地實施NCS，感測天線經放置接近於胸部區域。具有全功能收發器之習知RF詢答器將需要來自電池或電力線之有功功率，此歸因於大小及便利性之考量而限制長期監測能力。一被動且無需維護之穿戴式裝置係較佳的。UHF RFID系統係一良好候選。在圖8A中展示RFID方案。讀取器傳輸處於頻率f之下行鏈路信號，其中傳輸器 (Tx)信號亦通過循環器至讀取器天線。藉由標籤接收之下行鏈路信號遵循電子產品碼(EPC)協定。標籤無需任何有功電源，因為其等使用下行鏈路RF信號中之能量來供電。標籤上之電荷泵採集藉由標籤天線接收之小RF能量，接著邏輯電路調變反向散射上行鏈路信號。上行鏈路信號接著被讀取器接收器(Rx)天線接收且通過循環器。然而，幾個問題將限制用於NCS目的之系統效能。(1)存在直接從下行鏈路至上行鏈路之強自干擾。如圖8A中展示，由於循環器、直接Tx天線反射及來自附近物件之周圍反射之不充分隔離，強Tx至Rx洩漏仍然存在。歸因於被動標籤之低調變率，Rx信號經受來自Tx相位雜訊邊緣之大雜訊，此限制SNR及讀取器敏感度。(2)習知RFID系統通常採用循環器作為Tx/Rx雙工器，其具有有限頻寬且因此易受室內多路徑干擾。(3)習知EPC協定利用分時多重存取(TDMA)以處置標籤衝突，其中標籤在Aloha方案中選擇一隨機延遲時間。此隨機延遲將額外孔徑抖動引入至感測信號，此進一步使SNR降級且導致信號失真。 To experimentally implement NCS for heartbeats, sensing antennas were placed close to the chest area. Conventional RF transponders with fully functional transceivers will require active power from a battery or power line, which limits long-term monitoring capabilities due to size and convenience considerations. A passive and maintenance-free wearable device is preferred. UHF RFID systems are a good candidate. The RFID scheme is shown in Figure 8A. The reader transmits a downlink signal at frequency f, where the transmitter The (Tx) signal also passes through the circulator to the reader antenna. The downlink signal received through the tag follows the Electronic Product Code (EPC) protocol. The tags do not require any active power because they use the energy in the downlink RF signal to power them. A charge pump on the tag collects the small RF energy received by the tag's antenna, and logic circuitry then modulates the backscattered uplink signal. The uplink signal is then received by the reader receiver (Rx) antenna and passed through the circulator. However, several issues will limit system performance for NCS purposes. (1) There is strong self-interference directly from the downlink to the uplink. As shown in Figure 8A, strong Tx to Rx leakage still exists due to insufficient isolation of the circulator, direct Tx antenna reflections, and ambient reflections from nearby objects. Due to the low slew rate of passive tags, the Rx signal experiences large noise from the Tx phase noise edge, which limits SNR and reader sensitivity. (2) Conventional RFID systems usually use circulators as Tx/Rx duplexers, which have limited bandwidth and are therefore susceptible to indoor multipath interference. (3) The conventional EPC protocol uses time-division multiple access (TDMA) to handle tag conflicts, in which tags select a random delay time in the Aloha scheme. This random delay introduces additional aperture jitter to the sensed signal, which further degrades SNR and causes signal distortion.
為解決所有此等問題，可使用一諧波RFID系統。如圖8B中展示，Tx信號係處於f，從而傳輸通過低通濾波器(LPF)至Tx天線。諧波標籤由下行鏈路RF信號供電給諧波標籤，且透過Rx天線及高通濾波器(HPF)在上行鏈路中反向散射處於2f之諧波信號。Tx及Rx頻譜良好地分離，且Rx信號幾乎不受Tx相位雜訊邊緣影響。讀取器RF前端使用LPF及HPF作為雙工器，且頻寬可較寬以用於室內多路徑免疫。同時，諧波標籤亦可在CDMA協定上運行，藉由讀取器同步諧波標籤以提供具有最小孔徑抖動之多標籤存取。 To solve all these problems, a harmonic RFID system can be used. As shown in Figure 8B, the Tx signal is at f, thereby transmitting through the low pass filter (LPF) to the Tx antenna. The harmonic tag is powered by the downlink RF signal, and the harmonic signal at 2f is backscattered in the uplink through the Rx antenna and high-pass filter (HPF). The Tx and Rx spectra are well separated, and the Rx signal is hardly affected by the Tx phase noise edge. The reader RF front-end uses LPF and HPF as duplexers, and the bandwidth can be wider for indoor multipath immunity. At the same time, harmonic tags can also run on the CDMA protocol, synchronizing harmonic tags with readers to provide multi-tag access with minimal aperture jitter.
在圖22A中展示諧波標籤之示意圖。天線1從讀取器接收下 行鏈路信號。信號之一部分經遞送至能量採集模組以供電給標籤控制電路，且標籤接收器解調變下行鏈路命令以進行適當空中通訊協定(air protocol)及對應邏輯運算。RF能量之其他部分耦合至非線性傳輸線(NLTL)以在上行鏈路中產生二次諧波信號，其藉由RF開關調變以輻射通過天線2。圖22B展示一例示性實施例之一PCB原型，從WISP平台修改其上之數位邏輯部分。 A schematic diagram of harmonic tags is shown in Figure 22A. Antenna 1 receives from the reader line link signal. A portion of the signal is delivered to the energy harvesting module to power the tag control circuitry, and the tag receiver demodulates the downlink command to perform appropriate air protocol and corresponding logic operations. Other portions of the RF energy couple into the non-linear transmission line (NLTL) to produce a second harmonic signal in the uplink, which is modulated by the RF switch to radiate through the antenna 2. FIG. 22B shows a PCB prototype according to an exemplary embodiment, with the digital logic portion modified from the WISP platform.
Ettus B200軟體定義無線電(SDR)經程式化為諧波RFID讀取器。Tx局部振盪器(LO)經設定在1GHz且Rx LO設定在2GHz，其等具有相同時脈源以維持同調諧波收發器方案。 The Ettus B200 software-defined radio (SDR) is programmed as a harmonic RFID reader. The Tx local oscillator (LO) is set at 1GHz and the Rx LO is set at 2GHz, both with the same clock source to maintain a coherent harmonic transceiver scheme.
圖23中展示一例示性生命徵象監測設定。一第一標籤在胸部區域中以感測心跳及呼吸，且第二標籤在左腕上以感測脈搏。胸帶及腕帶僅用於服裝上之便利標籤部署且無需皮膚接觸或彈性帶張力。標籤從SDR讀取器接收下行鏈路信號且將上行鏈路信號反向散射至讀取器天線。解調變NCS信號由LabVIEW處理且展示於螢幕上，其中白色曲線追蹤心跳且紅色曲線追蹤腕部脈搏。藉由具有0.8Hz至15Hz之帶通濾波器(BPF)處理波形。從心臟信號至脈搏信號之延遲係脈波傳遞時間(PPT)，其可用於估計血壓。圖24A及圖24B展示從胸部RFID標籤收集之心跳及呼吸之解調變NCS信號。圖24A中之上曲線係NCS信號之正規化振幅部分。可見，主要調變係心跳，然而稍微耦合呼吸。正交接收器中之振幅與相位調變之間的隔離給出呼吸波形與心跳波形之間的明確分離，如干擾計類比中繪示。在數位BPF(0.8Hz至15Hz)之後，心跳信號經清晰擷取為下曲線。圖24B係NCS信號之正規化相位部分。原始相位波形經展示為上曲線，其中主要調變係呼吸，然而亦稍微耦合心跳。藉由數位BPF在一不同範圍 (0.1Hz至1.2Hz)中處理原始相位資料以擷取深紅色曲線中之經濾波呼吸信號。替代僅依靠先前工作中之頻帶濾波以分離呼吸信號及心跳信號，NCS可藉由正交方案區分外部及內部機械運動。 An exemplary vital sign monitoring setup is shown in Figure 23. A first tag is in the chest area to sense heartbeat and respiration, and a second tag is on the left wrist to sense pulse. Chest straps and wrist straps are used only for convenient label deployment on garments and do not require skin contact or elastic strap tension. The tag receives the downlink signal from the SDR reader and backscatters the uplink signal to the reader antenna. The demodulated NCS signal is processed by LabVIEW and displayed on the screen, where the white curve tracks the heartbeat and the red curve tracks the wrist pulse. The waveform is processed by a band-pass filter (BPF) with a range of 0.8Hz to 15Hz. The delay from the heart signal to the pulse signal is the pulse transit time (PPT), which can be used to estimate blood pressure. Figures 24A and 24B show demodulated NCS signals of heartbeat and respiration collected from chest RFID tags. The upper curve in Figure 24A is the normalized amplitude portion of the NCS signal. It can be seen that the main modulation is heartbeat, but it is slightly coupled to breathing. The isolation between amplitude and phase modulation in a quadrature receiver gives a clear separation between the respiratory waveform and the heartbeat waveform, as illustrated in the interferometer analogy. After digital BPF (0.8Hz to 15Hz), the heartbeat signal is clearly captured as a lower curve. Figure 24B is the normalized phase portion of the NCS signal. The raw phase waveform is shown as the upper curve, where the main modulation is respiration, however there is also slight coupling to heartbeat. By digital BPF in a different range (0.1Hz to 1.2Hz), the raw phase data is processed to capture the filtered respiratory signal in the dark red curve. Instead of relying solely on frequency band filtering to separate respiratory and heartbeat signals in previous work, NCS can distinguish external and internal mechanical motion through an orthogonal scheme.
為量測心跳時間間隔，可精確偵測波形及相關聯峰間時間。時序精確性因此取決於特徵點之時間解析度及清晰度。藉由頻譜中之高頻分量更佳地反映時域中之尖銳邊緣或峰。然而，來自呼吸及主心室運動之低頻分量自然地具有非常大振幅且因此可超過用於精確時間間隔偵測之尖峰。如圖25A中展示，實曲線係NCS心跳信號且點劃曲線係ECG信號，ECG信號在SDR讀取器中同步為主鏈路。NCS之取樣率係每秒5000個樣本(Sps)，且ECG之取樣率係512Sps，最初受限於電極雜訊。ECG信號經升頻轉換至5000Sps以用於同步及圖形顯示。為藉由ECG量測心跳時間間隔，可使用各週期中之QRS複合波之峰。由於峰已為尖銳的，故可容易地定位其時序。然而，NCS信號直接量測機械運動且因此較平滑而不具有明顯峰值，此減小峰值偵測精確性。為擷取精確時序，需要尖峰特徵點。因此，必須進一步處理原始NCS信號以改良峰值偵測確定性。圖25B及圖25C展示同步NCS及ECG信號之頻譜。兩個頻譜經正規化至約1Hz之各自峰值強度值。與NCS信號相比較，ECG具有更強高頻(2Hz至8Hz)分量且因此具有更尖峰。然而，由於NCS中之直接運動調變、諧波反向散射設計及較高取樣率，雜訊底限遠低於ECG之雜訊底限。然而，歸因於相同心跳源之同步量測，兩個頻譜之頻率分量經合理地對準且共用類似分佈。 To measure heartbeat intervals, waveforms and associated peak-to-peak times can be accurately detected. Timing accuracy therefore depends on the time resolution and clarity of feature points. Sharp edges or peaks in the time domain are better reflected through high-frequency components in the spectrum. However, low frequency components from respiration and main ventricular motion naturally have very large amplitudes and can therefore exceed the peaks used for accurate time interval detection. As shown in Figure 25A, the solid curve is the NCS heartbeat signal and the dotted curve is the ECG signal, which is synchronized to the main link in the SDR reader. The sampling rate of NCS is 5000 samples per second (Sps), and the sampling rate of ECG is 512Sps, which is initially limited by electrode noise. The ECG signal is upconverted to 5000Sps for synchronization and graphic display. To measure the time interval between heartbeats by ECG, the peak of the QRS complex in each cycle is used. Since the peak is already sharp, its timing can be easily located. However, the NCS signal directly measures mechanical motion and is therefore smoother without significant peaks, which reduces peak detection accuracy. To capture accurate timing, peak feature points are needed. Therefore, the raw NCS signal must be further processed to improve peak detection certainty. Figures 25B and 25C show the spectrum of synchronized NCS and ECG signals. Both spectra are normalized to respective peak intensity values of approximately 1 Hz. Compared to the NCS signal, the ECG has stronger high frequency (2Hz to 8Hz) components and therefore has sharper peaks. However, due to the direct motion modulation, harmonic backscatter design and higher sampling rate in NCS, the noise floor is much lower than that of ECG. However, due to simultaneous measurements of the same heartbeat source, the frequency components of the two spectra are reasonably aligned and share similar distributions.
NCS信號具有約4.5Hz至6Hz之豐富高頻分量，但強度振幅比約1Hz之主要心跳信號低至少10dB。相比之下，ECG亦具有該等分 量但具有更高強度及雜訊。因此，可應用一直接頻譜等化：將一4Hz至7Hz帶通有限脈衝回應(FIR)濾波器應用至原始信號，且接著將濾波器之輸出放大13dB以加回至原始信號。為使此兩個信號時域對準，濾波器可經設計為零相位濾波器以消除相位延遲。FIR結構有利地用於保持線性相頻回應。在圖26A中展示經處理信號，其與各心跳循環之原始信號相比具有更多特徵點及尖峰。各心跳循環之最高峰特徵點經選擇為時序指示符，展示為圖26A中之三角形標記。 The NCS signal has rich high-frequency components of about 4.5Hz to 6Hz, but the intensity and amplitude are at least 10dB lower than the main heartbeat signal of about 1Hz. In contrast, ECG also has this division quantity but with higher intensity and noise. Therefore, a direct spectral equalization can be applied: a 4Hz to 7Hz bandpass finite impulse response (FIR) filter is applied to the original signal, and the output of the filter is then amplified by 13dB to be added back to the original signal. To align the two signals in the time domain, the filter can be designed as a zero-phase filter to eliminate the phase delay. FIR structures are advantageously used to maintain linear phase frequency response. The processed signal is shown in Figure 26A, which has more feature points and spikes than the original signal for each heartbeat cycle. The highest peak characteristic point of each heartbeat cycle is selected as a timing indicator, which is displayed as a triangle mark in Figure 26A.
心跳時間間隔經界定為一個循環與下一循環中之特徵點之間的時間。在圖26B中展示心跳時間間隔。針對原始NCS(虛線)、ECG(點劃線)及等化NCS(實線)信號計算心跳時間間隔。對於原始NCS及ECG信號，特徵點經選擇為最高正峰。由於基於心跳間時間計算心跳時間間隔，故水平軸係心跳指數而非時間。垂直軸係心跳時間間隔，且其倒數可被視為心率。所有三個曲線展示相同整體下降趨勢或等效地增大心率，此係因為量測係在身體鍛煉之後進行的。儘管此處未提供實況，但仍可進行以下觀察。與等化NCS心跳時間間隔相比，原始NCS歸因於不精確峰值偵測而具有較大變化；ECG信號歸因於512Sps之低取樣率而具有較大變化。在幾個心跳內之等化NCS中之更穩定心跳時間間隔變化具有生理意義。 The heartbeat interval is defined as the time between a characteristic point in one cycle and the next cycle. The heartbeat time intervals are shown in Figure 26B. The heartbeat time intervals are calculated for the original NCS (dotted line), ECG (dashed line) and equalized NCS (solid line) signals. For raw NCS and ECG signals, the feature points are selected as the highest positive peaks. Since the heartbeat interval is calculated based on the time between beats, the horizontal axis frames the heartbeat index rather than the time. The vertical axis plots the heartbeat time interval, and its reciprocal can be considered the heart rate. All three curves show the same overall downward trend or equivalent increase in heart rate since the measurements were taken after physical exercise. Although live action is not provided here, the following observations can be made. Compared with the equalized NCS heartbeat interval, the raw NCS has greater variability due to inaccurate peak detection; the ECG signal has greater variability due to the low sampling rate of 512 Sps. The change in time intervals between more stable beats in the equalized NCS over several beats has physiological significance.
使用相關聯天線設計策略分析天線對NCS效能之效應。當達成較佳天線阻抗匹配時，可改良能量耦合效率及SNR以偵測心電圖波形細節。 The effect of antenna on NCS performance is analyzed using relevant antenna design strategies. When better antenna impedance matching is achieved, energy coupling efficiency and SNR can be improved to detect ECG waveform details.
為示範NCS之操作原理，在CST Microwave Studio中建立一人體身軀電磁(EM)模擬模型，如圖27A中展示。從Zubal Phantom提取身軀之器官幾何性質及組織性質。感測天線經附接接近於胸部區域但無需接觸皮膚。所發射EM波部分傳輸至遠場，展示為灰色箭頭。RF能量之另一部分歸因於近場效應而耦合至身體中，展示為虛線箭頭。由於辯證邊界之移動，藉由心跳調變反向散射信號之相位。展示為黑色箭頭之經調變反向散射RF信號干擾直接傳輸(灰色箭頭)且被RF接收器接收。由於此兩個信號係來自相同源但具有不同路徑，故操作類似於一干擾計結構。內部心跳給出兩個信號之差分調變，且可從遠場RF量值解調變。同時，由呼吸或身體運動導致之胸部外部移動將改變兩個信號(灰色及黑色箭頭)之相位延遲(此可被稱為共同模式調變)且可從遠場RF相位解調變。可藉由正交混頻器容易且精確地分離接收器處之量值及相位資訊。 In order to demonstrate the operating principle of NCS, a human body electromagnetic (EM) simulation model was established in CST Microwave Studio, as shown in Figure 27A. Extract the geometric properties and tissue properties of the body's organs from Zubal Phantom. The sensing antenna is attached close to the chest area without touching the skin. The portion of the emitted EM wave transmitted to the far field is shown as a gray arrow. Another portion of the RF energy is coupled into the body due to near-field effects, shown as the dashed arrow. Due to the movement of the dialectical boundary, the phase of the backscattered signal is modulated by the heartbeat. The modulated backscattered RF signal shown as black arrow interferes with the direct transmission (grey arrow) and is received by the RF receiver. Since the two signals come from the same source but have different paths, the operation is similar to an interference meter structure. The internal heartbeat gives a differential modulation of the two signals and can be demodulated from the far-field RF magnitude. At the same time, external movement of the chest caused by breathing or body movement will change the phase delay of the two signals (gray and black arrows) (this can be called co-mode modulation) and can be demodulated from the far-field RF phase. The magnitude and phase information at the receiver can be easily and accurately separated by a quadrature mixer.
NCS之一部分係接近於外部及內部身體運動之感測天線。由於天線之近場區域中之人體組織之高介電常數，其S參數將顯著改變。從設計觀點而言，天線可被視為RF電路阻抗(通常約50Ω)與由自由空間及身軀構成之連結區域之阻抗之間的匹配組件，後者與天線相比將僅在自由空間中改變阻抗、頻率回應及輻射場型。對於圖27B中之CST模擬，當2GHz偶極天線在自由空間中操作時，天線之S11經展示為實線。然而，當該天線附接在胸部區域附近時，S11將偏移至點劃線，此意謂2GHz附近之頻率歸因於高反射而不再具有良好發射效率。存在兩個可能簡單解決策略：將操作頻率偏移至具有低S11之頻帶，或重新設計天線幾何性質以擬合原始2GHz頻帶。虛線係重新設計之天線，其與所存在身軀匹配。處於2GHz之反射從-3dB大幅改良至-18dB。 Part of the NCS is a sensing antenna close to external and internal body movements. Due to the high dielectric constant of human tissue in the near-field region of the antenna, its S-parameters will change significantly. From a design point of view, the antenna can be seen as a matching component between the impedance of the RF circuit (usually around 50Ω) and the impedance of the connection area formed by free space and the body, which will only change the impedance in free space compared to the antenna , frequency response and radiation field pattern. For the CST simulation in Figure 27B, S11 of the antenna is shown as a solid line when the 2GHz dipole antenna operates in free space. However, when the antenna is attached near the chest area, the S 11 will shift to the dotted line, which means that frequencies around 2GHz no longer have good emission efficiency due to high reflections. There are two possible simple solutions: shifting the operating frequency to a band with low S 11 , or redesigning the antenna geometry to fit the original 2GHz band. The dotted line is the redesigned antenna to match the existing body. The reflection at 2GHz is greatly improved from -3dB to -18dB.
為進一步調查天線匹配效應之效能，圖28展示在一天線放置於圖28B中之胸部上時處於2GHz之功率流。在圖28A中，原始天線1具有點劃線，且圖28B之經修改天線2具有虛線。人體身軀之橫剖面經繪示有左(L)肺、右(R)肺及心臟。在相同驅動信號強度及顏色輪廓標度下，可觀察到從圖28A中之非匹配天線耦合至身軀之能量遠小於圖28B中之匹配狀況之能量。較強能量耦合亦增大反向散射信號之總強度。因此，在相同雜訊底限之情況下，將改良SNR及感測敏感度兩者。 To further investigate the effectiveness of antenna matching effects, Figure 28 shows the power flow at 2 GHz with an antenna placed on the chest in Figure 28B. In Figure 28A, the original antenna 1 has a dotted line, and the modified antenna 2 of Figure 28B has a dashed line. The cross section of the human body is shown with the left (L) lung, right (R) lung and heart. Under the same drive signal strength and color profile scale, it can be observed that the energy coupled to the body from the unmatched antenna in Figure 28A is much less than the energy in the matched condition in Figure 28B. Stronger energy coupling also increases the overall intensity of the backscattered signal. Therefore, both SNR and sensing sensitivity will be improved with the same noise floor.
在一例示性實施例中，為在一便利且高效能感測平台上實施NCS，利用一諧波反向散射RFID系統。NCS天線係諧波標籤之部分，諧波標籤之示意圖在圖22A中展示。標籤經設計為從讀取器採集下行鏈路RF能量以供電給標籤電路之被動裝置。藉由電荷泵採集由天線A(Ant.A)接收之RF能量之部分以操作接收器及微控制器單元(MCU)。RF能量之其他部分耦合至用於二次諧波產生之非線性傳輸線(NLTL)中以透過天線B(Ant.B)反向散射至讀取器。RF開關使用開關鍵控(OOK)將諧波信號調變為上行鏈路基頻帶。對標籤MCU執行分碼多重存取(CDMA)協定以達成多標籤案例中之較佳同步及效能。圖22B展示用於例示性諧波標籤之印刷電路板(PCB)原型，其中NCS感測天線安裝至天線B連接器。來自天線B之上行鏈路RF信號亦藉由呼吸及心跳予以調變且接著由讀取器予以接收及解調變。藉由軟體定義無線電(SDR,Ettus B200)實施諧波讀取器。讀取器傳輸器(Tx)之局部振盪器(LO)經設定在基本頻率f，且接收器(Rx)LO經設定在二次諧波頻率2f。藉由相同頻率參考驅動Tx及Rx LO之兩個合成 器，因此讀取器經組態為諧波同調收發器。使用諧波反向散射(而非習知RFID系統)之一主要益處係下行鏈路與上行鏈路之寬頻率分離(broad frequency separation)，因此來自標籤之弱反向散射信號並不經受來自Tx洩漏之高相位雜訊邊緣。因此，敏感度及SNR可遠高於習知RFID方案。 In an exemplary embodiment, a harmonic backscatter RFID system is utilized to implement NCS on a convenient and high-performance sensing platform. The NCS antenna is part of the harmonic tag, a schematic diagram of the harmonic tag is shown in Figure 22A. Tags are designed to be passive devices that harvest downlink RF energy from the reader to power the tag circuitry. A portion of the RF energy received by Antenna A (Ant.A) is collected by a charge pump to operate the receiver and microcontroller unit (MCU). Other portions of the RF energy couple into the nonlinear transmission line (NLTL) used for second harmonic generation to backscatter through Antenna B (Ant.B) to the reader. RF switches use on-off keying (OOK) to modulate harmonic signals into the uplink baseband. Implement Code Division Multiple Access (CDMA) protocol on the tag MCU to achieve better synchronization and performance in multi-tag cases. Figure 22B shows a printed circuit board (PCB) prototype for an exemplary harmonic tag with the NCS sense antenna mounted to the antenna B connector. The uplink RF signal from antenna B is also modulated by breathing and heartbeat and is then received and demodulated by the reader. Implemented harmonic reader via Software Defined Radio (SDR, Ettus B200). The local oscillator (LO) of the reader transmitter (Tx) is set at the fundamental frequency f, and the receiver (Rx) LO is set at the second harmonic frequency 2f. Drive both Tx and Rx LOs with the same frequency reference reader, so the reader is configured as a harmonic coherent transceiver. One of the main benefits of using harmonic backscatter (instead of conventional RFID systems) is the broad frequency separation of the downlink and uplink, so that the weak backscattered signal from the tag does not suffer from the Tx Leakage of high phase noise edges. Therefore, the sensitivity and SNR can be much higher than conventional RFID solutions.
在圖23中展示NCS量測設定。一個標籤在胸部區域中以獲得心跳及呼吸，且另一標籤在左腕上以獲得脈搏。胸帶及腕帶用於服裝上之便利標籤部署且無需皮膚接觸或彈性帶張力。標籤從SDR讀取器接收下行鏈路信號且將上行鏈路信號反向散射至讀取器。解調變NCS信號由LabVIEW中之0.8Hz至15Hz之帶通濾波器(BPF)處理且展示於螢幕上，其中白色曲線追蹤心跳且灰色曲線追蹤腕部脈搏。從心臟信號至脈搏信號之延遲係脈波傳遞時間(PPT)，其可用於估計血壓。讀取器天線當前可距人1.5米至3米，此受限於RF功率採集及被動諧波轉換損耗。可藉由讀取器及標籤之自訂設計容易地改良該範圍。 The NCS measurement setup is shown in Figure 23. One tag is in the chest area to get heartbeat and respiration, and the other tag is on the left wrist to get pulse. Chest straps and wrist straps are used for convenient tag deployment on garments without the need for skin contact or elastic strap tension. The tag receives the downlink signal from the SDR reader and backscatters the uplink signal to the reader. The demodulated NCS signal is processed by a 0.8Hz to 15Hz band-pass filter (BPF) in LabVIEW and displayed on the screen, where the white curve tracks the heartbeat and the gray curve tracks the wrist pulse. The delay from the heart signal to the pulse signal is the pulse transit time (PPT), which can be used to estimate blood pressure. The reader antenna can currently be located 1.5 meters to 3 meters away from a person, which is limited by RF power harvesting and passive harmonic conversion losses. This range can be easily improved through custom designs of readers and tags.
一單極天線用作用於NCS之例示性實施例之感測天線，天線之S11在圖29A中展示為在天線在自由空間中操作時具有2.1GHz之中心頻率之實線。當NCS天線放置於胸部區域附近時，S11回應偏移至圖32A中之具有1.9GHz之中心頻率之虛線。約2.1GHz之反射現在非常高。為達成NCS中之大能量耦合及高SNR，下行鏈路信號可改變為950MHz，因此感測天線在1.9GHz下良好匹配。如圖29B中展示，實線係藉由處於1.9GHz(展示為圖29A中之頻率1之標記)之上行鏈路獲取之心跳信號。具有處於2GHz(圖29A中之頻率2)之上行鏈路之虛線及處於2.1GHz(圖29A中之頻率3)之點劃線歸因於耦合至身軀中之較少能量而具有非常弱NCS信 號。應注意，處於頻率2及頻率3之RF輻射效率仍相當高，分別在-10dB及-7dB之S11下估計為90%及80%，且因此NCS信號中之大部分降級可歸因於組織耦合之減小。在相同系統設定及提取程序(惟不同頻率除外)下進行所有量測。在相同系統雜訊底限下，較高NCS信號強度可增大SNR以復原更清晰波形細節。可沿著實線之良好匹配條件中之減小斜率觀察到可重複細節，此在具有處於2.0GHz及2.1GHz之上行鏈路之非匹配條件中幾乎不可見。 A monopole antenna is used as the sensing antenna for the exemplary embodiment of the NCS, S 11 of the antenna is shown in Figure 29A as a solid line with a center frequency of 2.1 GHz when the antenna is operating in free space. When the NCS antenna is placed near the chest area, the S 11 response shifts to the dashed line in Figure 32A with a center frequency of 1.9 GHz. Reflections around 2.1GHz are now very high. In order to achieve large energy coupling and high SNR in NCS, the downlink signal can be changed to 950MHz, so the sensing antenna is well matched at 1.9GHz. As shown in Figure 29B, the solid line is the heartbeat signal acquired through the uplink at 1.9 GHz (shown as the frequency 1 mark in Figure 29A). The dashed line with the uplink at 2 GHz (frequency 2 in Figure 29A) and the dotted line at 2.1 GHz (frequency 3 in Figure 29A) have very weak NCS signals due to less energy coupled into the body . It should be noted that the RF radiation efficiency at frequency 2 and frequency 3 is still quite high, estimated at 90% and 80% at S 11 at -10dB and -7dB respectively, and therefore most of the degradation in the NCS signal can be attributed to the tissue Reduction of coupling. All measurements were performed under the same system settings and extraction procedures (except for different frequencies). Under the same system noise floor, higher NCS signal strength can increase SNR to restore clearer waveform details. Repeatable detail can be observed along the decreasing slope of the solid line in well-matched conditions, which is barely visible in unmatched conditions with uplinks at 2.0 GHz and above 2.1 GHz.
在此段落中，一例示性NCS生命徵象監測系統具備基於高頻心跳分量之一減輕方法以對抗來自身體移動之干擾。藉由使用同步ECG校準，在即時心率量測中實驗性地示範一低誤差概率。 In this paragraph, an exemplary NCS vital signs monitoring system has a mitigation method based on high-frequency heartbeat components to combat interference from body movement. By using simultaneous ECG calibration, a low error probability is experimentally demonstrated in real-time heart rate measurement.
如上文提及，心電圖(ECG)、光學體積掃描(PPG)及聲學方法(諸如聽診器心音圖及超音波心回波圖)係用於量測心率及其可變性之當前技術，其中ECG經最佳建立為臨床標準。然而，此等方法皆在穿戴式感測系統中受到大量關注。為達成ECG中之良好信號品質，電極需要藉由不適導電膠及脫毛而進行直接皮膚接觸。儘管已嘗試穿戴式ECG服裝，但仍難以用於日常服飾。當前PPG裝置廣泛用於智慧型手錶、腕帶、貼片及腕部或手指上之夾具上，但其需要一緊密接觸以避免來自周圍光之失真及相對運動。PPG信號依靠繁重處理以獲得相當清晰脈搏波形，且低頻率範圍及高頻率範圍兩者中之詳細資訊經常丟失。氧含量之感測深度受到限制，使得PPG最常應用至具有反射模式中之淺血流或透射模式中之高血濃度之身體區域，而直接心臟運動量測係難以達成的。聽診器心音圖易受內 部雜訊(呼吸及語音)及外部干擾(聲音及振動)且僅在一控制實驗室環境中係實用的。超音波心回波圖難以實施為一穿戴式裝置，此係因為其塊體轉換器需要使用阻抗匹配凝膠直接接觸皮膚表面。另外，當亦可期望同時量測呼吸率/運作及血壓時，通常需要應變計，但來自腕帶及袖口張力之不適性阻礙長期使用，且亦可破壞睡眠或晝夜節律。亦已提出若干基於RF之方法，其中作為遠場之一RF射束輻射至胸部區域以由人體反向散射。呼吸及心跳信號皆在RF載波上調變且接著被接收器天線接收。若藉由一RFID進一步調變反向散射信號，則認為即將發生之皮膚接觸對於可靠地擷取呼吸及心跳之微小皮膚移動係重要的。若未藉由無標籤情況中之一數位ID(識別)調變反向散射信號，則來自任何其他非特定反向散射之干擾可係不利的。在具有或不具有個人標籤之情況下，身體運動將導致基於RF之心率估計之嚴重不精確性。 As mentioned above, electrocardiography (ECG), optical volumetric scanning (PPG) and acoustic methods (such as stethoscope phonocardiography and echocardiography) are the current technologies used to measure heart rate and its variability, with ECG being the most Best established as clinical standard. However, these methods have received a lot of attention in wearable sensing systems. In order to achieve good signal quality in ECG, the electrodes need to be in direct skin contact through non-conductive conductive glue and hair removal. Although wearable ECG garments have been tried, they are still difficult to use in everyday clothing. Currently, PPG devices are widely used in smart watches, wristbands, patches, and clips on the wrist or fingers, but they require a close contact to avoid distortion and relative motion from ambient light. PPG signals rely on heavy processing to obtain a fairly clear pulse waveform, and detailed information in both the low and high frequency ranges is often lost. The sensing depth of oxygen content is limited, making PPG most often applied to body areas with shallow blood flow in reflection mode or high blood concentration in transmission mode, where direct cardiac motion measurement is difficult to achieve. Stethoscope phonocardiogram susceptible to internal local noise (breathing and speech) and external interference (sound and vibration) and is only practical in a controlled laboratory environment. Echocardiography is difficult to implement as a wearable device because its bulk transducer requires direct contact with the skin surface using impedance matching gel. Additionally, strain gauges are often required when simultaneous measurement of respiratory rate/function and blood pressure is also desired, but discomfort from wristband and cuff tension prevents long-term use, and can also disrupt sleep or circadian rhythms. Several RF-based methods have also been proposed, in which an RF beam is radiated to the chest area as a far-field to be backscattered by the human body. Both breathing and heartbeat signals are modulated on the RF carrier and then received by the receiver antenna. If the backscattered signal is further modulated by an RFID, it is believed that impending skin contact is important to reliably capture the small skin movements of breathing and heartbeat. If the backscattered signal is not modulated by a digital ID in the tagless case, interference from any other non-specific backscatter can be detrimental. Body movement will lead to severe inaccuracies in RF-based heart rate estimation with or without personal tags.
在此段落中，一例示性NCS生命徵象監測系統具備基於高頻心跳分量之一減輕方法以對抗來自身體移動之干擾。藉由使用同步ECG校準，在即時心率量測中實驗性地示範一低誤差概率。 In this paragraph, an exemplary NCS vital signs monitoring system has a mitigation method based on high-frequency heartbeat components to combat interference from body movement. By using simultaneous ECG calibration, a low error probability is experimentally demonstrated in real-time heart rate measurement.
使用圖23中展示之實驗設定測試NCS技術之一實施例。一軟體定義無線電(SDR,Ettus B200)經程式化以用作為一諧波讀取器。在胸部及左腕區域處部署被動諧波標籤。胸帶及腕帶用於服裝上之便利標籤部署且無需皮膚接觸或彈性帶張力。NCS(量測)信號由讀取器Rx天線接收且由SDR諧波讀取器解調變。所得解調變心跳及腕部脈搏在螢幕上分別展示為淺色曲線及深色曲線。腕部脈搏相對於心跳之延遲係脈波傳遞時間 (「PTT」)，其可用於估計血壓。圖31展示來自胸部標籤之解調變信號。心跳信號係來自帶通濾波(BPF：0.8Hz至15Hz)之後的量測信號之振幅。從0.1Hz至1.2Hz之BPF之後的量測信號之相位導出呼吸信號。 One embodiment of the NCS technology was tested using the experimental setup shown in Figure 23. A software-defined radio (SDR, Ettus B200) was programmed to function as a harmonic reader. Deploy passive harmonic tags on the chest and left wrist areas. Chest straps and wrist straps are used for convenient tag deployment on garments without the need for skin contact or elastic strap tension. The NCS (measurement) signal is received by the reader Rx antenna and demodulated by the SDR harmonic reader. The resulting demodulated heartbeat and wrist pulse are displayed on the screen as light curves and dark curves respectively. The delay between the wrist pulse and the heartbeat is the pulse wave transit time ("PTT"), which can be used to estimate blood pressure. Figure 31 shows the demodulated signal from the chest tag. The heartbeat signal is the amplitude of the measured signal after band-pass filtering (BPF: 0.8Hz to 15Hz). The respiratory signal is derived from the phase of the measured signal after the BPF of 0.1Hz to 1.2Hz.
儘管NCS可隔離外部機械移動與內部移動(諸如來自心跳之呼吸及來自腕部脈搏之手部運動)，但在身體運動之特性頻譜分量接近於生命徵象之特性頻譜分量時，量測信號仍可受到大身體移動干擾。此額外耦合類似於藉由振幅調變(AM)與頻率調變(FM)之混合之信號污染，尤其在AM及FM邊帶之一者非常大時。當包含大運動時，在圖32A中展示原始NCS量測信號。在前40秒中，受測試人員靜坐以建立清晰心跳信號之基線以供參考，如插圖中展示。在介於40s與70s之間的週期期間，人員猛烈地揮動其等之手部。在介於70s與100s之間的週期期間，人員移動其身體且在第97秒站起，接著繼續左右移動其身體。在第120秒，人員復原坐姿15s。在約第135秒，人員再次站起直至在第145秒再次靜坐。在圖32B中展示具有及不具有移動之20秒窗之頻譜。頻譜經正規化至約1.5Hz之主峰(不具有移動)之強度且放大至較低強度部分。濾出低於0.8Hz及高於15Hz之分量。淺灰色曲線係在從不具有身體移動之10s至30s之時間週期期間的頻譜，且深灰色曲線係在心跳信號受到大身體移動干擾時的85s至105s期間。不具有身體移動之頻譜不僅展示約1.5Hz之主峰，而且亦清晰展示較高頻率諧波。身體移動通常在較低頻率下具有強特性頻率。心跳之主譜峰被具有僅高於0dB之信號干擾比(「SIR」)之身體移動嚴重扭曲。然而，處於較高頻率之分量較少被身體移動污染。峰A、B及C之SIR分別為3.4dB、5.9dB及7.6dB。 Although NCS can isolate external mechanical movement from internal movement (such as breathing from the heartbeat and hand movement from the wrist pulse), the measurement signal can still be detected when the characteristic spectral components of body movements are close to the characteristic spectral components of vital signs. Disturbed by large body movements. This additional coupling is similar to signal contamination by the mixing of amplitude modulation (AM) and frequency modulation (FM), especially when one of the AM and FM sidebands is very large. When large motion is involved, the raw NCS measurement signal is shown in Figure 32A. During the first 40 seconds, the subject sits quietly to establish a baseline of clear heartbeat signals for reference, as shown in the illustration. During the period between the 40s and 70s, the subject violently waved their hands. During the period between 70s and 100s, the person moves his body and stands up at 97 seconds, then continues to move his body from side to side. At the 120th second, the person returns to the sitting position for 15 seconds. At approximately 135 seconds, the subject stands again until sitting down again at 145 seconds. The spectrum of a 20 second window with and without movement is shown in Figure 32B. The spectrum is normalized to the intensity of the main peak (without movement) at approximately 1.5 Hz and amplified to the lower intensity portion. Filter out components below 0.8Hz and above 15Hz. The light gray curve is the spectrum during the time period from 10s to 30s when there is no body movement, and the dark gray curve is during the period 85s to 105s when the heartbeat signal is interfered by large body movement. The spectrum without body movement not only shows the main peak at about 1.5Hz, but also clearly shows higher frequency harmonics. Body movements usually have strong characteristic frequencies at lower frequencies. The main spectral peak of the heartbeat is severely distorted by body movement with a signal-to-interference ratio ("SIR") just above 0dB. However, components at higher frequencies are less contaminated by body movements. The SIRs of peaks A, B and C are 3.4dB, 5.9dB and 7.6dB respectively.
由於心跳信號之高頻分量具有較佳SIR，故其等可用於心跳計數而具有來自身體移動之較少影響。NCS信號通過4Hz至5.5Hz之一BPF以擷取三次諧波之B峰，且當人員在第97秒站起時在圖33A(實線)中使用95s至99s期間的同步心電圖(ECG)(虛線)展示。三次諧波之選擇係歸因於其合理SIR及大量值。高頻分量亦與心率相乘以減小計數誤差。如在圖38中之前兩個心跳中展示，NCS中存在六個最大峰及最小峰，因此十二個總峰用於心率估計。然而，在96s至98s期間，人員站起且原始NCS信號大幅改變，同時在使用直接凝膠塗漿護皮墊之情況下之ECG信號亦失真，然而其QRS特徵歸因於其高頻特性而保持相當清晰。存在根據ECG信號之三個心跳及來自NCS之三次諧波之十七個峰。NCS遺漏一個峰，但心跳計數之誤差在此三個心跳內僅為5.6%且針對圖33A中之範圍係2.4%。 Since the high frequency components of the heartbeat signal have better SIR, they can be used for heartbeat counting with less influence from body movement. The NCS signal is passed through a BPF of 4Hz to 5.5Hz to capture the B peak of the third harmonic, and a synchronized electrocardiogram (ECG) from 95s to 99s is used in Figure 33A (solid line) when the person stands up at 97 seconds ( dashed line) is shown. The third harmonic was chosen due to its reasonable SIR and large number of values. The high-frequency components are also multiplied with the heart rate to reduce counting errors. As shown in the previous two heartbeats in Figure 38, there are six maximum and minimum peaks in the NCS, so twelve total peaks are used for heart rate estimation. However, between 96s and 98s, the person stood up and the original NCS signal changed significantly. At the same time, the ECG signal in the case of using a direct gel-applied skin pad was also distorted. However, its QRS characteristics were attributed to its high-frequency characteristics. Keep it fairly clear. There are three heartbeats based on the ECG signal and seventeen peaks from the third harmonic of the NCS. NCS misses one peak, but the error in beat counting is only 5.6% within these three beats and 2.4% for the range in Figure 33A.
為分析即時心率，可在時域處均勻地重新取樣心跳計數。心跳計數係基於最大峰及最小峰之數目，但各峰之時間資訊並非均勻分佈為一離散信號。因此，心跳資料與三次樣條擬合且均勻分佈有0.05s之時間解析度。在圖33B中展示心跳計數對時間。實曲線及虛曲線分別為NCS及ECG計數結果，且底部曲線(標記為ERROR)係誤差。最大誤差發生在人員揮動手部時的第40秒之後。在圖33B之插圖中展示用於此週期之心跳計數曲線。在整個160s計數之後，ECG之結果係243(91.1beats/min之平均心率)，且NCS係241(90.4beats/min之平均心率)。誤差係-0.8%。在圖33C中展示藉由NCS(實線)及ECG(虛線)之三次諧波監測之心率曲線。藉由0.5Hz之一低通濾波器處理曲線。在下文表I中展示基於二次諧波、三次諧波及四次諧波之峰計數(圖32B中之A、B、C)之平均心率及誤差。使用藉由ECG獲得之心率曲線及NCS之各諧波計算同調係數。NCS之二次諧 波給出歸因於低SIR之最大誤差。 To analyze real-time heart rate, beat counts can be resampled uniformly in the time domain. Heartbeat counting is based on the number of maximum and minimum peaks, but the time information of each peak is not evenly distributed as a discrete signal. Therefore, the heartbeat data are fitted with a cubic spline and uniformly distributed with a time resolution of 0.05 s. Heartbeat counts versus time are shown in Figure 33B. The solid curve and the dashed curve are the NCS and ECG counting results respectively, and the bottom curve (marked ERROR) is the error. The maximum error occurs after the 40th second when the person waves his hand. The heartbeat count curve for this cycle is shown in the inset of Figure 33B. After the entire 160s count, the ECG result is 243 (average heart rate of 91.1 beats/min), and the NCS is 241 (average heart rate of 90.4 beats/min). The error is -0.8%. The heart rate curve monitored by the third harmonic of NCS (solid line) and ECG (dashed line) is shown in Figure 33C. Process the curve with a 0.5Hz low-pass filter. The average heart rate and error based on the peak counts of the second, third and fourth harmonics (A, B, C in Figure 32B) are shown in Table I below. The coherence coefficient is calculated using the heart rate curve obtained by ECG and each harmonic of the NCS. Second harmonic of NCS The wave gives the largest error due to low SIR.
與其他心跳去雜訊或計數方法相比較，當前使用之提取方法可提供即時心率，而無需計算需要資料之一長持續時間之整個頻譜以擷取合理頻率解析度。運算負載亦為小的，此可容易地在具有一基本微控制器之穿戴式裝置上執行。 Compared to other heartbeat denoising or counting methods, currently used extraction methods can provide real-time heart rates without having to calculate the entire spectrum over a long duration of data required to capture reasonable frequency resolution. The computational load is also small and this can be easily executed on a wearable device with a basic microcontroller.
長期睡眠計分在臨床設定中係非常重要的以監測患者之復原且在家中監測兒童及成人。以一具成本效益之方式，通常可藉由上身移動連同心跳及呼吸監測評估睡眠品質。取代歸因於感測器及電極之皮膚接觸而引起不適之習知多導睡眠圖(PSG)，此段落呈現使用胸部區域中之一單一被動射頻(RF)識別(RFID)標籤之RF近場同調感測(NCS)而無需皮膚接觸之一例示性睡眠監測系統及方法，其中可同步提取心率、呼吸節律及運動偵測。運動分類係基於具有半監督式學習之支援向量機(SVM)。可在91.06%之測試情況中正確辨識突然身體抽搐、搖動及轉身。亦在運動人為誤差校正之後改良心率偵測精確性。 Long-term sleep scoring is very important in clinical settings to monitor patient recovery and to monitor children and adults at home. In a cost-effective manner, sleep quality can often be assessed by upper body movement together with heartbeat and respiratory monitoring. Instead of conventional polysomnography (PSG), which causes discomfort due to skin contact of sensors and electrodes, this section presents RF near-field synchronization using a single passive radio frequency (RF) identification (RFID) tag in the chest area An exemplary sleep monitoring system and method for sensing (NCS) without skin contact, in which heart rate, respiratory rhythm and motion detection can be simultaneously extracted. Motion classification is based on support vector machines (SVM) with semi-supervised learning. Sudden body twitching, shaking and turning can be correctly identified in 91.06% of test situations. It also improves heart rate detection accuracy after correcting for exercise artifacts.
本實施例試圖具有同時監測生命徵象及身體運動之能力以按一低成本且非侵入性方式進行睡眠計分，此段落呈現可基於具有近場同調感測(NCS)之被動UHF RFID系統之一睡眠計分系統，其增強耦合至身 體中之RF能量且因此增加來自身體上及身體內部之心跳、呼吸及運動之反向散射信號。可在具有唯一數位識別(ID)之無線電信號上調變導致動態介電邊界之機械移動，此可容易地延伸至藉由一單一RFID讀取器監測多個標籤及人員。在一些實施例中，待研究人員可僅穿戴可整合於織物中之一單一胸部標籤且無需皮膚接觸或運動約束，如圖34中展示。 This embodiment attempts to have the ability to simultaneously monitor vital signs and body movements to perform sleep scoring in a low-cost and non-invasive manner. This paragraph presents one of the passive UHF RFID systems that can be based on near-field coherent sensing (NCS). Sleep Scoring System with Enhanced Coupling to the Body RF energy in the body and therefore increases backscattered signals from heartbeat, breathing and movement on and within the body. Modulation on a radio signal with a unique digital identification (ID) can lead to mechanical movement of dynamic dielectric boundaries, which can be easily extended to monitoring multiple tags and people with a single RFID reader. In some embodiments, the subject may wear only a single chest tag that is integrated into the fabric and requires no skin contact or movement restrictions, as shown in Figure 34.
已針對PPG及ECG信號中之運動及其他人為誤差偵測開發基於生命徵象波形之變形之信號異常偵測演算法，其中採用用於SVM之分類之時間及頻譜特性、多層(MLP)感知器、決策樹或其他分類器。運動偵測演算法係基於偵測NCS波形在搖動、轉身及突然身體抽搐之上身移動期間的改變。一SVM分類器僅使用休息時之信號特徵進行訓練且可偵測運動期間的異常特徵。 A signal anomaly detection algorithm based on the deformation of vital sign waveforms has been developed for motion and other human error detection in PPG and ECG signals, which uses temporal and spectral characteristics for SVM classification, multi-layer (MLP) perceptron, Decision trees or other classifiers. The motion detection algorithm is based on detecting changes in the NCS waveform during upper body movements such as shaking, turning, and sudden body twitches. An SVM classifier is trained using only resting signal features and can detect abnormal features during exercise.
可在運動源之近場區內部署NCS之天線時執行NCS。為評估睡眠品質，將諧波RFID標籤放置於胸部區域中，此在一無線電識別及感測平台(WISP)上原型化。使用國家儀器Ettus軟體定義無線電(SDR)B200實施諧波讀取器。按每秒106個樣本實行類比轉數位及數位轉類比轉換以擷取精確基頻帶波形。讀取器傳輸器頻率f係1GHz且具有10kHz類比基頻帶；對應讀取器接收器頻率係2GHz且具有20kHz基頻帶。 NCS can be performed when the NCS antenna is deployed in the near field area of the moving source. To assess sleep quality, harmonic RFID tags were placed in the chest area, which was prototyped on a Wireless Identification and Sensing Platform (WISP). Implement a harmonic reader using the National Instruments Ettus Software Defined Radio (SDR) B200. Perform analog-to-digital and digital-to-analog conversion at 10 6 samples per second to capture accurate baseband waveforms. The reader transmitter frequency f is 1 GHz and has a 10 kHz analog base band; the corresponding reader receiver frequency is 2 GHz and has a 20 kHz base band.
執行一受控資料收集以模擬睡眠期間的以下案例： A controlled data collection was performed to simulate the following cases during sleep:
1)靜止狀態：對象有意識地保持靜止。 1) Still state: The subject consciously remains still.
2)身軀運動：5秒之輕微身軀運動。 2) Body movement: slight body movement for 5 seconds.
3)身體抽搐：0.5秒至2秒之身軀及手臂之一快速、高能運動。 3) Body twitching: rapid, high-energy movement of the body and arms for 0.5 to 2 seconds.
4)轉身：對象在1秒至2秒內左轉或右轉。 4) Turn: The object turns left or right within 1 to 2 seconds.
收集資料1小時，其中NCS信號取樣率係每秒500個樣本。按1分鐘之時間間隔執行模擬移動。室內多路徑效應可被忽略，因為延遲擴展遠低於NCS取樣時間。 Data is collected for 1 hour, in which the NCS signal sampling rate is 500 samples per second. Perform simulated movements at 1-minute intervals. Indoor multipath effects can be ignored because the delay spread is much lower than the NCS sampling time.
身體之表面及內部移動(主要由測試期間的呼吸及心跳信號組成)在標籤反向散射上調變且可被解調變數位資料之信號處理擷取。NCS資料之振幅及相位兩者擷取具有不同權重之呼吸、心跳及運動資訊。相位對整個標籤運動最敏感，而振幅對小標籤運動較不敏感但係由耦合至內部運動之近場導致之天線特性之一強函數。圖35A展示休息時之原始DC濾波振幅及相位資料。 Surface and internal movements of the body (mainly composed of breathing and heartbeat signals during the test) are modulated on the tag backscatter and can be captured by signal processing that demodulates the variable digital data. Both the amplitude and phase of the NCS data capture breathing, heartbeat, and motion information with different weights. Phase is most sensitive to overall tag motion, while amplitude is less sensitive to small tag motion but is a strong function of the antenna characteristics resulting from near-field coupling to internal motion. Figure 35A shows the raw DC filter amplitude and phase data at rest.
藉由簡單濾波從相位提取呼吸節律。在圖35B中，一20階巴特威士(Butterworth)濾波器用於使介於0.01Hz與1Hz之間的頻率通過。在圖35C中，藉由移除含有自主呼吸資訊之低於0.6Hz之頻率而從NCS振幅提取心跳。一線性相位濾波器用於移除高於10Hz之所有頻譜含量。 Respiratory rhythm is extracted from phase by simple filtering. In Figure 35B, a 20th order Butterworth filter is used to pass frequencies between 0.01 Hz and 1 Hz. In Figure 35C, heartbeats are extracted from NCS amplitudes by removing frequencies below 0.6 Hz that contain spontaneous breathing information. A linear phase filter is used to remove all spectral content above 10Hz.
心跳信號可在輕微喘息之事件期間受到呼吸信號嚴重干擾。簡單濾波亦可在阻塞性呼吸之情況中使信號失真。 The heartbeat signal can be severely interfered with by the respiratory signal during mild wheezing events. Simple filtering can also distort the signal in the case of obstructive breathing.
使用精確心跳及呼吸資訊進行睡眠計分之運動偵測未直接藉由簡單濾波達成。運動影響心跳及呼吸兩者之波形特徵，然而可藉由校正受運動影響之信號而擷取精確生命信號。執行一逐心跳分段以達成運動之更精細時間解析度。在具有多個峰值之非靜止心跳波形中難以進行精確 峰值偵測。本方法開始於多層級一維小波分解，使用多西貝10級小波(Daubechies 10-tap wavelet)識別在重構之後導致與心跳之最大相關性之係數。在圖35D中展示含有心跳波形之主要分量之8層級(NCS-d8)細節係數之重構波形。可在此階段執行精確峰值偵測，其中藉由每分鐘200個心跳之一最大心率判定最小峰值距離之額外約束。 Motion detection using accurate heartbeat and breathing information for sleep scoring is not directly achieved through simple filtering. Movement affects the waveform characteristics of both heartbeat and respiration, but accurate vital signals can be captured by correcting the signals affected by movement. Perform a beat-by-beat segmentation to achieve finer temporal resolution of motion. Difficulty performing accurate measurements in non-quiescent heartbeat waveforms with multiple peaks Peak detection. The method starts with multi-level one-dimensional wavelet decomposition, using Daubechies 10-tap wavelet to identify the coefficients that after reconstruction lead to the greatest correlation with the heartbeat. A reconstructed waveform containing 8-level (NCS-d8) detail coefficients of the main components of the heartbeat waveform is shown in Figure 35D. Accurate peak detection can be performed at this stage, with the additional constraint of determining the minimum peak distance by a maximum heart rate of 200 beats per minute.
基於受運動影響之波形與在休息時獲得之波形之間的差異識別運動特徵。而且，特徵有利地係穩健的以考量呼吸、心跳及信號振幅隨時間之變化。相對心跳時間間隔及相對心跳均方根(RMS)係基於不期望心跳時間間隔及RMS在心跳間顯著變化之假設之特徵。計算統計平均值、方差、偏度及峰度以擷取運動與休息時之波形之間的主要差異，其中應用五個心跳之一啟發窗。在相同窗內之0.6Hz至10Hz之範圍內之正規化頻譜功率用作除心跳諧波以外的另一特徵運動。 Movement signatures are identified based on differences between waveforms affected by movement and waveforms obtained at rest. Furthermore, the features are advantageously robust to accounting for changes in respiration, heartbeat, and signal amplitude over time. Relative beat time intervals and relative beat root mean square (RMS) are characteristics based on the assumption that beat time intervals and RMS are not expected to vary significantly from beat to beat. Statistical mean, variance, skewness and kurtosis are calculated to capture the main differences between exercise and rest waveforms, using a heuristic window of five heartbeats. The normalized spectral power in the range of 0.6 Hz to 10 Hz within the same window is used as another characteristic motion besides heartbeat harmonics.
運動分類係基於上述七個特徵。已採用具有徑向基函數核之SVM來偵測運動。半監督式學習用於訓練模型，即，訓練僅使用休息時之自主呼吸收集之資料執行。排除用於訓練之運動資料減少來自冗餘學習之運動之過度擬合及一般化問題以及減少在訓練期間執行移動常式之不便性。圖36A及圖36B展示NCS心跳及對應運動偵測。藉由人工註釋結果評估運動偵測演算法之效能。 Sports classification is based on the seven characteristics mentioned above. SVM with radial basis function kernel has been used to detect motion. Semi-supervised learning is used to train the model, i.e., training is performed using only data collected from spontaneous breathing at rest. Excluding motion data for training reduces overfitting and generalization problems from redundantly learned motions and reduces the inconvenience of executing movement routines during training. Figure 36A and Figure 36B show NCS heartbeat and corresponding motion detection. Evaluate the performance of motion detection algorithms through manual annotation results.
表II展示各運動類別之正確肯定(TP)及錯誤否定(FN)情況之數目。錯誤肯定(FP)表示在未實際發生之情況下用信號傳輸運動，此主要歸因於不規則呼吸模式及心跳偵測誤差。一逐心跳運動分類給出97.58%之精確性、88.28%之敏感度及98.10%之特異性。表III展示具有各 類別中之心跳數目之混淆矩陣。圖36C展示移除運動人為誤差之後的改良心率估計之一實例。使用30拍窗長度之一移動平均值估計心率。 Table II shows the number of correct positive (TP) and false negative (FN) cases for each movement category. False positives (FP) represent signaling motion without actually occurring, primarily due to irregular breathing patterns and heartbeat detection errors. A heartbeat-by-beat motion classification gave 97.58% accuracy, 88.28% sensitivity, and 98.10% specificity. Table III shows the Confusion matrix of the number of heartbeats in the category. Figure 36C shows an example of improved heart rate estimation after motion artifact is removed. Heart rate is estimated using a moving average with a window length of 30 beats.
可憑藉良好精確性偵測身體抽搐運動，而緩慢轉身可被錯誤分類為休息。精確性可取決於訓練資料及相關演算法。使用休息時之自主呼吸(包含具有偶爾深呼吸之規則呼吸)訓練實驗實施例。使用一規則呼吸模式訓練增大對運動之敏感度且導致不規則呼吸之情況中之增大FP。 Twitching body movements can be detected with good accuracy, while slow turns can be misclassified as resting. Accuracy may depend on training data and related algorithms. Example of a training experiment using spontaneous breathing at rest (including regular breathing with occasional deep breaths). Training using a regular breathing pattern increases sensitivity to movement and leads to increased FP in conditions of irregular breathing.
量測動物生命徵象之當前方法通常涉及複雜且侵入性準備程序且導致受測試動物之主要不適以致其等通常需要被麻醉。例如，用於心跳波形之心電圖(ECG)需要具有良好電接觸之身體電極且因此難以應用至具有厚毛皮之哺乳動物、具有鱗甲或殼之爬行動物、具有羽毛之鳥類及 具有鱗之魚類。諸如腳底及嘴唇之裸露皮膚區域通常具有不足電信號且可對觸摸敏感。通常可使用麻醉執行肌肉電極。類似地，身體表面條件亦導致光學體積掃描(PPG)設定中之複雜性，此限制其應用至動物。聽診及超音波需要緊密皮膚接觸或阻抗匹配凝膠以獲得清晰信號，此需要高程度之動物處置。基於微小皮膚運動之多普勒(Doppler)遠場反向散射之射頻(RF)方法具有非特定無線頻道且易受任何周圍運動干擾。呼吸通常係主導信號且變為對精確心跳偵測之一主要干擾。基於傳輸線模型之RF方法再次需要皮膚電極之良好阻抗匹配。小動物歸因於有限信號敏感度而造成大部分此等RF方法之進一步挑戰。 Current methods of measuring animal vital signs often involve complex and invasive preparation procedures and cause major discomfort to the animals being tested so that they often need to be anesthetized. For example, electrocardiography (ECG) for heartbeat waveforms requires body electrodes with good electrical contact and is therefore difficult to apply to mammals with thick fur, reptiles with scales or shells, birds with feathers, and Fish with scales. Exposed skin areas such as the soles of the feet and lips often have insufficient electrical signals and can be sensitive to touch. Muscle electrodes can usually be performed using anesthesia. Similarly, body surface conditions also lead to complexities in optical volume scanning (PPG) setup, which limits its application to animals. Auscultation and ultrasound require close skin contact or impedance matching gel to obtain a clear signal, which requires a high degree of animal handling. The radio frequency (RF) method based on Doppler far-field backscattering of small skin movements has a non-specific wireless channel and is susceptible to interference from any surrounding movement. Breathing is often the dominant signal and becomes one of the major interferences to accurate heartbeat detection. RF methods based on transmission line models again require good impedance matching of skin electrodes. Small animals pose a further challenge for most of these RF methods due to limited signal sensitivity.
藉由多工無線電信號上之天線特性之近場調變之本發明NCS方法無需皮膚接觸且提供有意識小動物之生命徵象之長期監測之一有效解決方案。在圖37A及圖37B中展示適合於搭配小動物使用之兩個例示性NCS設定之示意圖。圖37A中之無線感測利用諧波RFID(無線電頻率識別)架構，其使被動感測標籤變得廉價且無需維護，但需要一特定多工讀取器。此版本可適於在具有耐風雨被動標籤之自然生境中部署，且從操作者或固定裝置上之一附近讀取器收集生命徵象。諧波系統之使用藉由分離傳輸器(Tx)及接收器(Rx)之頻帶而減少自擾，改良信號敏感度以及信雜比(SNR)，且減少測試RF Tx信號之所需強度，所有此等對感測小動物之生命徵象係有利的。照射於動物身體上之NCS信號可遠低於先前技術(例如0.1mW/cm2及0.15W/kg)以遵循囓齒動物模型中之健康及安全標準。在圖37A中，Ettus X310軟體定義無線電(SDR)之諧波讀取器透過讀取器Tx天線傳輸處於約950MHz之f之下行鏈路信號。下行鏈路信號供電給被動諧波RFID標籤且接著轉換為處於2f之二次諧波頻率以作為目標動物身體 之近場範圍內之NCS感測信號。只要生命信號在感測標籤天線之此近場範圍內(通常約所採用波長的三分之一)而無需任何皮膚接觸，動物身體上及動物身體內部之運動可耦合至反向散射信號以由讀取器Rx天線接收。NCS中之高SNR允許微小內部運動(諸如人類腕部脈搏波形)之精確量測，此對小動物之生命徵象係有利的。相對於讀取器之主要整體標籤天線運動將主要反映為相位調變，其可與由於相對於近場中之標籤天線之介電邊界運動之量值調變自然地分離。源自感測標籤之信號可含有一唯一識別(ID)碼以達成分碼多重存取，此改良頻道隔離以防非特定干擾且實現多個感測標籤之同時讀取。被動感測標籤之製造類似於習知RFID標籤，其除無需維護之便利部署以外亦給出低成本生產及靈活基板選擇。 The NCS method of the present invention through near-field modulation of antenna characteristics on multiplexed radio signals does not require skin contact and provides an effective solution for long-term monitoring of vital signs of conscious small animals. Schematic diagrams of two exemplary NCS settings suitable for use with small animals are shown in Figures 37A and 37B. Wireless sensing in Figure 37A utilizes harmonic RFID (radio frequency identification) architecture, which makes passive sensing tags cheap and maintenance-free, but requires a specialized multiplexed reader. This version may be suitable for deployment in natural habitats with weather-resistant passive tags and to collect vital signs from the operator or one of the nearby readers on a fixed installation. The use of harmonic systems reduces self-interference by separating the transmitter (Tx) and receiver (Rx) frequency bands, improves signal sensitivity and signal-to-noise ratio (SNR), and reduces the required strength of the test RF Tx signal, all This is beneficial for sensing the vital signs of small animals. The NCS signal irradiated on the animal body can be much lower than previous technologies (such as 0.1mW/ cm2 and 0.15W/kg) to comply with health and safety standards in rodent models. In Figure 37A, the Ettus X310 software-defined radio (SDR) harmonic reader transmits a f downlink signal at approximately 950 MHz through the reader Tx antenna. The downlink signal powers the passive harmonic RFID tag and is then converted to the second harmonic frequency of 2f as an NCS sensing signal within the near field range of the target animal's body. As long as the vital signal is within this near-field range of the sensing tag antenna (typically about one-third of the wavelength used) without any skin contact, motion on and within the animal's body can be coupled to the backscattered signal by Reader Rx antenna reception. The high SNR in NCS allows accurate measurement of small internal movements (such as human wrist pulse waveforms), which is beneficial for vital signs in small animals. The dominant overall tag antenna motion relative to the reader will be primarily reflected as a phase modulation, which can be naturally separated from the magnitude modulation due to dielectric boundary motion relative to the tag antenna in the near field. The signal from the sensing tag can contain a unique identification (ID) code to achieve decoding multiple access. This improved channel isolation prevents non-specific interference and enables simultaneous reading of multiple sensing tags. The manufacturing of passive sensing tags is similar to conventional RFID tags. In addition to convenient deployment without maintenance, it also provides low-cost production and flexible substrate options.
替代地，圖37B中之設定用RF纜線取代讀取器至標籤頻道，此減少干擾且可適於便利地部署於具有繁重操作者訊務或具有其他干擾源之一室內實驗室中。讀取器Tx天線直接傳輸處於2f之NCS感測信號且在受測試動物之近場範圍內。接著由讀取器Rx天線接收藉由生命徵象調變之NCS信號，此可根據所考量應用進行部署。 Alternatively, the setup in Figure 37B replaces the reader-to-tag channel with an RF cable, which reduces interference and can be conveniently deployed in an indoor laboratory with heavy operator traffic or with other interference sources. The reader Tx antenna directly transmits the NCS sensing signal at 2f and within the near field range of the test animal. The NCS signal modulated by the vital signs is then received by the reader Rx antenna, which can be deployed according to the application under consideration.
為比較小動物心臟波形上之NCS生命徵象，首先對一囓齒動物模型執行同步NCS及ECG量測，此不僅對於臨床試驗係重要的，而且亦具有非常微弱且快速心跳，從而提供一更具挑戰測試。麻醉一朗伊萬斯(Long-Evans)實驗室大鼠(溝鼠)(編碼為#110)，以藉由剃刀及Veet凝膠霜完成腹部脫毛以進行ECG電極部署，如圖38A中展示。嘗試在兩個爪子上使用彈簧夾及導電貼紙墊，但ECG信號非常弱且雜訊多。藉由一橡膠綜將具有圖38B中之架構之感測標籤天線放置於頸部區域之後方附近而無需脫毛。亦使用合理NCS信號嘗試包含沿著尾部、在胸部前方及沿著後腿之其 他天線放置。在圖38B中展示一代表性5分鐘記錄，且插圖展示第三分鐘內之半秒內之波形細節。圖38B中之ECG及NCS之心電圖波形呈現如圖38C中展示之非常類似心跳間時間間隔，但詳細特徵時序(例如NCS特徵相對於ECG之S及T特徵點之間的時序之位置)可需要進一步特性化。根據時序比較，NCS可取代ECG以進行基於心率變化(HRV)之行為研究。在圖38D中藉由具有額外0.5Hz至2.5Hz低通濾波之NCS同步收集呼吸波形，從而允許無法單獨藉由ECG達成之進一步心肺分析。 To compare NCS vital signs on cardiac waveforms in small animals, simultaneous NCS and ECG measurements were first performed on a rodent model, which is not only important for clinical trials but also has very weak and fast heartbeats, thus providing a more challenging test. . A Long-Evans laboratory rat (Code #110) was anesthetized for abdominal hair removal by razor and Veet gel cream for ECG electrode deployment, as shown in Figure 38A. Tried using spring clips and conductive sticker pads on both claws, but the ECG signal was very weak and noisy. The sensing tag antenna with the structure in Figure 38B is placed near the back of the neck area via a rubber harness without hair removal. Also try to use reasonable NCS signals including others along the tail, in front of the chest and along the hind legs. his antenna placement. A representative 5-minute recording is shown in Figure 38B, and the inset shows waveform details for half a second during the third minute. The electrocardiogram waveform presentation of the ECG and NCS in Figure 38B is very similar to that shown in Figure 38C, but detailed feature timing (such as the position of the NCS feature relative to the timing between the S and T feature points of the ECG) may be needed Further characterization. Based on time series comparison, NCS can replace ECG for behavioral studies based on heart rate variation (HRV). In Figure 38D respiratory waveforms are collected simultaneously by NCS with additional 0.5Hz to 2.5Hz low pass filtering, allowing further cardiopulmonary analysis not achievable by ECG alone.
NCS量測藉由近場幾何改變調變之標籤天線特性，而ECG量測藉由微小皮膚電流感應之身體電位差，微小皮膚電流進一步由心臟電刺激及血流感應。從此觀點，NCS具有類似於心衝擊圖(BCG)之一波形且係比ECG更直接之一心跳運動量測。NCS亦較少經受來自皮膚條件及準備步驟之變化。 NCS measures the characteristics of the tag antenna modulated by near-field geometric changes, while ECG measures the body potential difference induced by tiny skin currents, which are further stimulated by cardiac electrical stimulation and blood flow sensing. From this point of view, NCS has a waveform similar to a ballist cardiogram (BCG) and is a more direct measurement of heartbeat motion than ECG. NCS is also less susceptible to changes in skin conditions and preparation procedures.
在確認麻醉大鼠上之心肺信號之後，接著示範圖39中之可能非侵入性NCS設定，其等對於ECG及其他習知技術對有意識小動物係非常困難的(若有可能)。名為「Timo」之一寵物金倉鼠(金倉鼠(Mesocricetus))在其籠睡眠區中受到監測，如圖39A中展示。在籠外應用圖37A及圖37B中之無線及有線NCS架構兩者。對於無線版本，藉由下行鏈路信號供電給被動諧波標籤，下行鏈路信號之部分經轉換為二次諧波以作為耦合至倉鼠身體中之NCS感測信號。讀取器Rx天線距標籤約1.5m。對於有線版本，感測天線經安裝於睡眠區之右側上，其直接傳輸NCS感測信號。在圖39B中，在倉鼠不注意之情況下獲取其呼吸及心跳之生命徵象。生命徵象之振幅經正規化至整個記錄週期之最大值。插圖展示約第八秒之心跳波形細節。波形特徵不僅類似於記錄期間的各心跳，而且亦類似 於圖38B中之麻醉大鼠中之波形特徵。在應用具有20之窗大小之移動平均值之後，針對心跳時間間隔提取波形之最小負值，如圖39C中展示。倉鼠心跳時間間隔比大鼠心跳時間間隔長約20%。為示範對小鳥之NCS適用性，量測名為「Banana」之一寵物觀賞長尾鸚鵡(虎皮鸚鵡，亦稱為相思鸚鵡)，如圖39D至圖39D中展示。有意識鳥類之生命徵象監測可實現行為研究以及鳥類健康檢查中之新能力。圖39D示範有線實驗設定。諧波Tx天線傳輸NCS感測信號，NCS感測信號經耦合至長尾鸚鵡身體中。諧波Rx天線亦整合至棲木且能夠獲取具有圖3F中之經提取心跳時間間隔之如圖3E中展示之心跳及呼吸兩者之詳細特徵。天線部署對於有線NCS設定係非常便利的。在長尾鸚鵡行為之簡單觀察之後，識別鳥類通常站立之棲木上之若干位置。選擇一個最頻繁位置且安裝天線。在NCS量測期間，不干擾寵物長尾鸚鵡之晝夜節律。 After confirming the cardiopulmonary signals on the anesthetized rat, we proceed to demonstrate in Figure 39 a possible non-invasive NCS setup, which is very difficult (if not possible) for conscious small animals with ECG and other conventional techniques. A pet golden hamster (Mesocricetus) named "Timo" was monitored in the sleeping area of his cage, as shown in Figure 39A. Both the wireless and wired NCS architectures in Figures 37A and 37B are applied outside the cage. For the wireless version, the passive harmonic tag is powered by a downlink signal, and part of the downlink signal is converted to the second harmonic as an NCS sensing signal coupled into the hamster's body. The reader Rx antenna is about 1.5m away from the tag. For the wired version, a sensing antenna is mounted on the right side of the sleeping area, which directly transmits the NCS sensing signal. In Figure 39B, vital signs of the hamster's breathing and heartbeat were obtained without the hamster's attention. The amplitude of vital signs was normalized to the maximum value over the entire recording period. The illustration shows details of the heartbeat waveform at about the eighth second. The waveform characteristics are not only similar to each heartbeat during the recording, but also Waveform characteristics in anesthetized rats in Figure 38B. After applying a moving average with a window size of 20, the smallest negative value of the waveform is extracted for the heartbeat interval, as shown in Figure 39C. The time interval between hamster heartbeats is about 20% longer than the time interval between rat heartbeats. To demonstrate the applicability of NCS to small birds, a pet ornamental parakeet (budgie, also known as acacia) named "Banana" was measured, as shown in Figure 39D to Figure 39D. Vital sign monitoring of conscious birds enables new capabilities in behavioral research and bird health examinations. Figure 39D demonstrates the wired experimental setup. The harmonic Tx antenna transmits the NCS sensing signal, which is coupled into the parakeet's body. The harmonic Rx antenna is also integrated into the perch and is able to acquire detailed features of both heartbeat and breathing as shown in Figure 3E with the extracted heartbeat time intervals in Figure 3F. Antenna deployment is very convenient for wired NCS settings. After simple observation of parakeet behavior, identify several locations on the perch where the bird usually stands. Choose a most frequent location and install the antenna. During NCS measurement, the circadian rhythm of pet parakeets is not disturbed.
在名為「Blimp」之一***寵物龜(四爪陸龜，亦稱為霍斯菲爾德陸龜(Horsfield’s tortoise)或中亞陸龜)上進行下一示範，如圖39G至圖39I中展示。***陸龜係達到月球軌道之第一個脊椎動物物種且歸因於其等之亞冬眠能力而對長太空旅行之研究係重要的，此使生命徵象之連續長期記錄變得甚至更具科學意義。海龜具有由小氣隙分離之一硬殼及軟身體組織之一身體結構。藉由ECG及超音波之生命徵象獲取僅在使用頸部或肌肉探針時係可行的，此兩者導致動物之主要不適性。殼之生理特徵及外溫性連同適當診斷方法之缺乏因此使龜類急救護理變得非常困難。鳥類及囓齒動物之心臟具有含有兩個心房及兩個心室之四個腔(類似於人類)，且因此圖38B、圖39B及圖39E中之NCS波形具有類似特徵。相比之下，陸龜具有含有兩個心房及一個心室之三腔心臟，且NCS心電圖具 有不同特徵，然而仍可精確擷取心率。在圖39G中展示NCS設定。圖39D中之一類似天線對經放置於玻璃籠外部之雪松木片下方。歸因於身體結構，呼吸及心跳信號皆嵌入圖39H中之NCS振幅之原始資料中，此係因為呼吸期間不存在殼表面移動。心跳信號可清晰(如插圖中之淺陰影區域中展示)，但在呼吸週期期間，其將被歸因於肺之相對較大體積之強呼吸信號(深陰影區域)覆蓋。為分離兩個重疊信號以進行精確率估計，採用連續小波變換(CWT)以提取圖39I中之兩個波形之峰值特徵。亦已嘗試將天線直接放置於椎殼及腹甲上，其中亦可清晰記錄NCS心跳及呼吸信號。 The next demonstration is conducted on a Russian pet tortoise named “Blimp” (a four-clawed tortoise, also known as Horsfield’s tortoise or Central Asian tortoise), shown in Figures 39G to 39I. The Russian tortoise is the first vertebrate species to reach lunar orbit and is important for the study of long space travel due to their ability to sub-hibernate, making continuous long-term recording of vital signs even more scientifically significant . Sea turtles have a body structure that is separated by small air gaps between a hard shell and soft body tissues. Vital sign acquisition by ECG and ultrasound is only possible when using neck or muscle probes, both of which cause major discomfort to the animal. The physiological characteristics and ectotherm of the shell combined with the lack of appropriate diagnostic methods make emergency care of turtles very difficult. The hearts of birds and rodents have four chambers with two atria and two ventricles (similar to humans), and therefore the NCS waveforms in Figures 38B, 39B, and 39E have similar characteristics. In contrast, tortoises have a three-chamber heart with two atria and one ventricle, and the NCS electrocardiogram have different characteristics, but can still accurately capture heart rate. NCS settings are shown in Figure 39G. A similar pair of antennas in Figure 39D was placed under cedar wood chips on the outside of a glass cage. Due to body structure, breathing and heartbeat signals are embedded in the raw data of NCS amplitude in Figure 39H since there is no shell surface movement during breathing. The heartbeat signal may be clear (as shown in the lightly shaded area in the illustration), but during the respiratory cycle it will be overshadowed by the strong respiratory signal (dark shaded area) attributed to the relatively large volume of the lungs. In order to separate the two overlapping signals for accuracy estimation, the continuous wavelet transform (CWT) is used to extract the peak features of the two waveforms in Figure 39I. Attempts have also been made to place antennas directly on the vertebral shell and plastron, where NCS heartbeat and respiratory signals can also be clearly recorded.
最後但非最不重要的，RF信號可在水中之一短範圍內工作，尤其近場耦合。儘管ECG遙測術係可行的，但儀器植入程序僅適合於在可執行無偏量測之前具有長達一周之復原週期之較大魚類。魚類學者因此長期探索其他非侵入性解決方案以擷取小魚中之行為研究及進化生物學之生理資訊。在圖39J至圖39L中示範名為「Glee」之一寵物五彩博魚(鬪魚，亦稱為暹羅鬪魚)之生命徵象量測。解調變NCS相位信號經解釋為圖39K中之胸鰭移動，其具有含有藉由非同步視訊記錄確認之頻率之一週期性波形。據信，圖39L中之解調變NCS量值信號表示源自心跳之週期性波形。 Last but not least, RF signals can operate over a short range in water, especially with near-field coupling. Although ECG telemetry is possible, the instrumentation procedure is only suitable for larger fish that have a recovery period of up to a week before unbiased measurements can be performed. Ichthyologists have therefore long explored other non-invasive solutions to capture physiological information for behavioral studies and evolutionary biology in small fish. In Figures 39J to 39L, the measurement of vital signs of a pet colorful pommel fish named "Glee" (also known as the Siamese pommel fish) is demonstrated. The demodulated NCS phase signal was interpreted as pectoral fin movement in Figure 39K, which has a periodic waveform with a frequency confirmed by asynchronous video recording. It is believed that the demodulated NCS magnitude signal in Figure 39L represents a periodic waveform derived from a heartbeat.
如圖37A及圖37B中展示，藉由一軟體定義無線電(SDR)執行諧波讀取器。使用Ettus USRP X310及UBX 160MHz RF子板之組合。在吾人之實驗期間，下端Ettus USRP B200/210亦可經組態為用於此應用之諧波讀取器，但X310具有用於波形細節之高解析度之較高資料取樣率。為運作為圖37A及圖37B中之一同調諧波收發器，Tx鏈及Rx鏈共用相 同RF時脈源。Rx鏈中之合成器將局部振盪器(LO)頻率組態為Tx鏈中之OL頻率之兩倍。藉由場可程式化閘極陣列(FPGA)產生Tx基頻帶信號，且將Rx基頻帶饋送至FPGA中進行解調變以進行資料記錄及顯示。 As shown in Figures 37A and 37B, the harmonic reader is implemented via a software defined radio (SDR). Using the combination of Ettus USRP X310 and UBX 160MHz RF daughter board. During our experiments, the lower end Ettus USRP B200/210 could also be configured as a harmonic reader for this application, but the X310 has a higher data sampling rate for high resolution of waveform details. To operate as a co-harmonic transceiver in Figures 37A and 37B, the Tx chain and Rx chain share a phase Same as RF clock source. The synthesizer in the Rx chain configures the local oscillator (LO) frequency to twice the OL frequency in the Tx chain. The Tx baseband signal is generated by a field programmable gate array (FPGA), and the Rx baseband is fed to the FPGA for demodulation for data recording and display.
圖37A及圖37B中展示之無線及有線版本兩者可應用於NCS。在圖37A中之無線版本中，在修改無線識別及感測平台(WISP)及非線性傳輸線(NLTL)之情況下設計被動諧波標籤。NLTL係電感器及變容器之梯形結構，因此使用變容器符號來表示諧波標籤及諧波產生器。在所採集RF功率下操作之諧波標籤可容易地大量部署於許多感測目標上或相同目標之多個點上。同時，對於單點監測，圖37B中之有線版本較易於應用至室內動物實驗室。此處之諧波產生器仍可係如以前的NLTL以提供高轉換效率。NLTL之輸入埠處之低通濾波器隔離從NLTL至讀取器之直接諧波反射，且NLTL之輸出埠處之高通濾波器將基本頻率信號衰減至Tx天線。然而，在不具有如被動標籤中之嚴功率約束之情況下，具有適當頻率回應之任何主動或被動倍頻器可取代有線版本中之NLTL。在實驗期間，嘗試將自訂二極體及商用被動倍頻器(CRYSTEK CPPD-0.85-2)作為諧波產生器，此兩者提供滿意效能。亦可使用讀取器CDMA技術將有線NCS系統延伸至多個點，但系統成本將按比例增大。在吾人之先前工作中示範諧波系統之益處。作為一簡要概述，諧波系統提供Tx鏈與Rx鏈之間的非常好隔離，因此Rx雜訊底限可非常低以改良SNR及讀取器Rx敏感度兩者。繼而，Tx功率亦可非常低以仍維持生命徵象感測所需之SNR，此消除關於照射至活體組織之RF功率之任何進一步健康顧慮。 Both wireless and wired versions shown in Figures 37A and 37B can be applied to NCS. In the wireless version in Figure 37A, passive harmonic tags are designed with modifications to the Wireless Identification and Sensing Platform (WISP) and Non-Linear Transmission Line (NLTL). NLTL is a ladder structure of inductor and varactor, so the varactor symbol is used to represent harmonic labels and harmonic generators. Harmonic tags operating at harvested RF power can be easily deployed in large numbers on many sensing targets or at multiple points on the same target. At the same time, for single-point monitoring, the wired version in Figure 37B is easier to apply to indoor animal laboratories. The harmonic generator here can still be the same as the previous NLTL to provide high conversion efficiency. A low-pass filter at the NLTL's input port isolates direct harmonic reflections from the NLTL to the reader, and a high-pass filter at the NLTL's output port attenuates the fundamental frequency signal to the Tx antenna. However, without strict power constraints as in passive tags, any active or passive frequency multiplier with appropriate frequency response can replace the NLTL in the wired version. During the experiment, a custom diode and a commercial passive frequency multiplier (CRYSTEK CPPD-0.85-2) were tried as harmonic generators, and both provided satisfactory performance. Reader CDMA technology can also be used to extend the wired NCS system to multiple points, but the system cost will increase proportionally. The benefits of harmonic systems were demonstrated in our previous work. As a brief overview, harmonic systems provide very good isolation between the Tx chain and the Rx chain, so the Rx noise floor can be very low to improve both SNR and reader Rx sensitivity. In turn, the Tx power can also be very low to still maintain the SNR required for vital sign sensing, which eliminates any further health concerns regarding RF power irradiated into living tissue.
藉由具有LabVIEW介面之電腦控制SDR。DAC(數位轉類 比轉換器)及ADC(類比轉數位轉換器)之取樣率經組態為皆處於10MSps。來自DAC之基頻帶輸出之頻率係1MHz。當Tx LO頻率係950MHz時，從Tx輸出之信號係951MHz。在諧波轉換之後，Rx信號之中心頻率將為1902MHz。處於1900MHz之Rx LO經設定為Tx LO之兩倍。因此，Rx基頻帶頻率係2MHz以由ADC進行取樣。數位化基頻帶信號經降頻轉換且將LabVIEW中之取樣減少至5kSps之NCS取樣率。 Control the SDR via a computer with LabVIEW interface. DAC (Digital to Classification) The sampling rates of the analog to digital converter) and the ADC (analog to digital converter) are configured to be both at 10MSps. The frequency of the baseband output from the DAC is 1MHz. When the Tx LO frequency is 950MHz, the signal output from the Tx is 951MHz. After harmonic conversion, the center frequency of the Rx signal will be 1902MHz. The Rx LO at 1900MHz is set to twice the Tx LO. Therefore, the Rx baseband frequency is 2MHz to be sampled by the ADC. The digitized baseband signal was down-converted and sampled in LabVIEW to an NCS sampling rate of 5 kSps.
儘管已關於一或多個特定實施例描述本發明，但將理解，可在不脫離本發明之精神及範疇的情況下製作本發明之其他實施例。因此，本發明被視為僅受隨附發明申請專利範圍及其合理解釋限制。 Although the invention has been described with respect to one or more specific embodiments, it will be understood that other embodiments of the invention can be made without departing from the spirit and scope of the invention. Accordingly, the present invention is deemed to be limited only by the patentable scope of the appended invention claims and their reasonable interpretation.
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