1306024 九、發明說明： 【發明所屬之技術領域】 本發明係有關於血壓量測，特別是有關於非侵 企壓量測祕及方法。 ^ 【先前技術】 企壓ί 量Γ裝置約可分為兩大類：一為侵入式(― 置’另一為非侵入式(n〇ninvasive)血壓量測裝置。 在臨床應用上，侵入式血壓量測裝置通常是將導管贫 血官插人橈動脈(radial汹巧)或左心室(left ventricle)以 ，續量測血壓波形，進而作為評估續功能之參考，且之 3方ίίΐΐΪΪΪ之準雜。然而’侵人式血壓量測雖然 精準仁部可此成感染、大量流血以及血栓之 二’亦不可能採用侵人式血壓量測^式，取而 弋 i t寿i用 fe#4(aUSCUlat〇ry meth〇d)、震盪法(oscill_tric method)血壓計來進行非侵入式之血壓量測。 、非侵入式血壓制裝置之縣法所使狀卫 血壓計(Sphygm〇man〇meter)，其優點為裝備簡單、^ 或居家看護使用。但是其量測方ί在 使用者之經驗與判斷，因此常受主觀因素 行連續之血壓量測(其僅能提供收縮壓與 5;ϊ=ίί值)’而一般自動血壓計所採用之振盪式血壓 篁測法亦無法取得連續血壓之變化。 心此/a _目前對於賴方面疾狀診斷常須借助連續血壓 不Ϊ部位之動脈所量測到之血壓波形，因塵力波 日反射、時間延遲…等因素而造成波形之 因此，本發明利用身體不同部位之血频號建4‘型t 1306024 核型觀察血皆系統之特性，亦利用此模型進行兩個不 =壓訊號之轉換。藉此’當兩個身體部位間血管系統被， 則可利用賴型將$取得部位之血壓訊餘估不綠得 之血壓訊號。 σ 【發明内容】 本發_提供—辦以式連續血㈣娜統及方法， 藉以改良習知血壓量測之缺失。 本發明提供-種非侵人式連續血壓制系統及方法，复 13 .兩血壓感測裝置，係用以量測一第一 = =並對應輸出一第一血壓訊號與一第二血以 、目路’係連接此兩血壓感測裝置，_以控制此兩血壓感 =置之制壓力缝此兩血壓_裝置可以連續操作；一^ 〜處理電路，係連接此兩血壓感測裝置，並對此、二 放大、交直流訊號分離與紐處理；以及一系^函 ’並對此m壓訊號進行數位濾波，以^ 糸統函式與複數個相關特徵值分析。 θ本發明提供一種非侵入式連續血壓量測方法，其包含. ί測I第—量測點之—第—錢訊號；量測—第二量測點之- 二，峨；_第-血壓訊賴該第二血壓訊號進行放 齡^直流纖分離以及雜訊濾除處理；產生該第-血壓訊號 $第二血壓減所對應技壓值；以及_ [血壓訊號盘 :第一血壓訊號進行系統函式分析，其中建立該第一、第二^ ^訊號之複數個特徵值與轉換函式以比較該第_、第二血壓訊 艰•之關係。 【實施方式】 1306024 ^本發明將會詳細描述一些實施例如下。然而，除了所揭 ，之巧例外，本發明還可以廣泛地在運用在其他的實施例施 =本發明的細林料纽_限定，乃以其後的申請專 為準。而為提供更清楚的描述及使熟悉該項技藝者能理 本卷明的發明内容’圖示内各部分並沒有依照其相對尺寸繪 圖，某些尺寸與其他相關尺度之比例會被突顯而顯得誇張，且 不相關之細節部分也未完全繚出，以求圖示的簡潔。 請參照第一圖，其為本發明之一較佳實施例丨⑻之系統 方塊，。-第-氣囊112A與-第-壓力感測器114A以及一 第二氣囊112B與一第二壓力感測器114B係分別形成兩血壓 感測裝置，此兩血壓感測裝置係用以量測人體之一第一量測點 與一第二量測點之血壓’並且對應輸出一第一血壓訊號以及一 第二血壓訊號。在本實施例中，第一量測點係可以是手臂部分 而第一：!：測點係可以是手腕部分’然不限於此例。一怪壓控制 電路120係連接此兩血壓感測裝置(壓力感測器114A、U4B), 恆壓控制電路120係用以控制氣囊112A、112B之内壓以使得 壓力感測器114A、114B可以連續感測血壓訊號。一信號處理 電路130係連接此兩血壓感測裝置(壓力感測器114A、114B)， 信號處理電路130係用以對壓力感測器114A、114B所輸出之 第一血壓訊號與第二血壓訊號進行放大、交直流訊號分離以及 濾、波處理。一系統函式分析裝置140係連接信號處理電路13〇 以接收信號處理電路130所輸出之第一、第二血壓訊號，並且 對第一、第二血壓訊號進行數位濾波處理以進行系統函式與複 數個相關特徵值分析。 在本實施例中，恆壓控制電路120係包含：兩放大器 122A、122B ; —恆壓控制器124 ;兩數位/類比轉換器126A、 126B;兩電流驅動器127A、127B;以及兩幫浦128A、128B。 其中，第一放大器122A與第二放大器122B係對應連接第一 壓力感測器114A與第二壓力感測器114B’係用以對應接收並 1306024 . 放大第一、第二血壓訊號。恆壓控制器124係連接第一放大器 122A與第二放大器122B ’係用以接收其等輸出之第一、第二 j訊號，並且亦分卿第―、第二血壓訊舰行類比/數位 ，換以及驗處理，進而將第―、第二▲壓訊號分別與一預設 轭圍，進行比較，並依比較結果對應輸出兩控制信號。其中， 放大器122A、122B係放大倍率設計為25〇倍之儀表放大器， 然不限於此，而上述之類比/數位轉換與濾波處理係分別為12 位元類比/數位轉換以及移動平均濾波處理，而預設範圍值係 包含35〜45 mmHg。1306024 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to blood pressure measurement, and more particularly to non-invasive pressure measurement methods and methods. ^ [Prior Art] The device can be divided into two categories: one is invasive (the other is a non-invasive (n〇ninvasive) blood pressure measuring device. In clinical application, invasive blood pressure The measuring device usually inserts the catheter anemia officer into the radial artery or the left ventricle to continuously measure the blood pressure waveform, and then serves as a reference for evaluating the continuous function, and the three parties are λ. However, 'invasive blood pressure measurement, although the precision of the benevolent part can be infected, a large number of bleeding and thrombus two' is also impossible to use the invasive blood pressure measurement type, and 弋it life i with fe#4 (aUSCUlat〇 Ry meth〇d), oscill_tric method sphygmomanometer for non-invasive blood pressure measurement. Non-invasive blood pressure system device sphygmomanometer (Sphygm〇man〇meter), its advantages It is used for simple equipment, ^ or home care. However, its measurement is based on the user's experience and judgment, so it is often subjectively measured by continuous blood pressure measurement (which can only provide systolic blood pressure and 5; ϊ = ίί value) 'And the oscillating type used by the general automatic sphygmomanometer Pressure sputum measurement method can not achieve continuous blood pressure changes. Heart / a _ current diagnosis of Lai disease often requires the use of continuous blood pressure to measure the blood pressure waveform of the blood pressure, due to dust wave reflection, time Therefore, the waveform is caused by factors such as delay, etc. The present invention uses the blood frequency number of different parts of the body to construct the 4' type t 1306024 karyotype to observe the characteristics of the blood system, and also uses this model to convert two non-pressure signals. When 'the vascular system between the two body parts is taken, the blood pressure signal of the acquired part of the blood pressure signal can be estimated by using the sputum type. σ [Invention content] The present invention provides a continuous blood (four) The method and method for improving the lack of conventional blood pressure measurement. The present invention provides a non-invasive continuous blood pressure system and method, and a dual blood pressure sensing device for measuring a first == and Corresponding to output a first blood pressure signal and a second blood, the eye path is connected to the two blood pressure sensing devices, _ to control the two blood pressure senses = the pressure of the system to seal the two blood pressure _ device can operate continuously; ~ Processing circuit, system Connected to the two blood pressure sensing devices, and the second, the AC and DC signal separation and the new processing; and a series of ^ ' and digitally filter the m pressure signal, to use the system function and a plurality of related features Value Analysis θ The present invention provides a non-invasive continuous blood pressure measurement method, which comprises: 测 Measure I - the measurement point - the first - money signal; the measurement - the second measurement point - two, 峨; The first blood pressure signal is subjected to the second blood pressure signal for ageing ^DC fiber separation and noise filtering processing; generating the first blood pressure signal $ second blood pressure minus corresponding technical pressure value; and _ [blood pressure signal disk: first The blood pressure signal performs a system function analysis, wherein a plurality of eigenvalues and conversion functions of the first and second signals are established to compare the relationship between the first and second blood pressure signals. [Embodiment] 1306024 ^ Some embodiments of the present invention will be described in detail below. However, the present invention may be broadly applied in other embodiments, except for the disclosure, which is based on the application of the present invention. In order to provide a clearer description and to enable those skilled in the art to understand the invention, the parts of the illustration are not drawn according to their relative dimensions, and the ratio of certain dimensions to other related scales will be highlighted. Exaggerated, and irrelevant details are not completely drawn out, in order to simplify the illustration. Please refer to the first figure, which is a system block of a preferred embodiment (8) of the present invention. The first airbag 112A and the first pressure sensor 114A and the second airbag 112B and the second pressure sensor 114B respectively form two blood pressure sensing devices for measuring the human body. One of the first measuring point and the second measuring point of the blood pressure 'and correspondingly output a first blood pressure signal and a second blood pressure signal. In this embodiment, the first measuring point system may be an arm portion and the first: !: the measuring point system may be a wrist portion', but is not limited to this example. A pressure control circuit 120 is connected to the two blood pressure sensing devices (pressure sensors 114A, U4B), and the constant voltage control circuit 120 is used to control the internal pressure of the air cells 112A, 112B so that the pressure sensors 114A, 114B can Continuously sense the blood pressure signal. A signal processing circuit 130 is connected to the two blood pressure sensing devices (pressure sensors 114A, 114B), and the signal processing circuit 130 is used to output the first blood pressure signal and the second blood pressure signal to the pressure sensors 114A, 114B. Amplification, AC and DC signal separation, and filtering and wave processing. A system function analyzing device 140 is connected to the signal processing circuit 13 to receive the first and second blood pressure signals output by the signal processing circuit 130, and digitally filter the first and second blood pressure signals for system function and A plurality of related eigenvalue analysis. In the present embodiment, the constant voltage control circuit 120 includes: two amplifiers 122A, 122B; - a constant voltage controller 124; two digital/analog converters 126A, 126B; two current drivers 127A, 127B; and two pumps 128A, 128B. The first amplifier 122A and the second amplifier 122B are connected to the first pressure sensor 114A and the second pressure sensor 114B' for receiving and 1306024. The first and second blood pressure signals are amplified. The constant voltage controller 124 is connected to the first amplifier 122A and the second amplifier 122B' for receiving the first and second j signals of the output thereof, and is also divided into the first and second blood pressure traffic lines analog/digital. The change and the inspection process further compare the first and second ▲ pressure signals with a predetermined yoke, and output two control signals according to the comparison result. Among them, the amplifiers 122A and 122B are instrumentation amplifiers whose magnification is designed to be 25 times, but are not limited thereto, and the analog/digital conversion and filtering processes described above are 12-bit analog/digital conversion and moving average filtering, respectively. The preset range value is 35~45 mmHg.
φ 第一數位/類比轉換器126A與第二數位/類比轉換器126B 係連接恆壓控制器124，係用以對應接收上述之兩控制信號並 輸出其等所相對之兩類比信號。第一電流驅動器127A與第二 電流驅動器127B係對應接收並放大此兩類比信號。第一幫浦 128A與第二幫浦128B係對應接收電流驅動器127A、127B所 輸出之兩類比信號’藉此調節第一幫浦128A與第二幫浦ι28Β 之充放氣操作以維持兩血壓感測裝置量測之壓力（氣囊、 112B之内壓）。其中，電流驅動器127A、127B係包含達林頓 放大電路。 鲁 本實施例中，信號處理電路130係包含：兩放大器122A、 122B;兩交直流訊號分離器i32A、132B;以及兩濾波器134A、 134B。放大器122A、122B係恆壓控制電路120之放大器，故 不再說明。而第一交直流訊號分離器132A與第二交直流訊號 分離器132B係對應接收放大器122A、122B所輸出之第一、 第二血壓訊號並進行交直流成分分離，在本實施例中，交直流 訊號分離器132A、132B係可以是直流減法電路，藉此將第一、 第二血壓訊號直流成分滤除。第一濾波器134A與第二渡波器 134B係對應接收交直流訊號分離器132八、132B輸出之第一、 第二血壓訊號並進行濾波處理後輸出信號處理電路13()。其中 第一濾波器134A與第二濾波器134B係分別包含四階 1306024The first digital/analog converter 126A and the second digital/analog converter 126B are connected to the constant voltage controller 124 for receiving the two control signals and outputting the two analog signals. The first current driver 127A and the second current driver 127B correspondingly receive and amplify the two analog signals. The first pump 128A and the second pump 128B are corresponding to the two analog signals output by the current driver 127A, 127B, thereby adjusting the charge and discharge operation of the first pump 128A and the second pump 12828 to maintain the two blood pressure senses. The pressure measured by the measuring device (airbag, internal pressure of 112B). Among them, the current drivers 127A and 127B include a Darlington amplifier circuit. In the present embodiment, the signal processing circuit 130 includes two amplifiers 122A, 122B, two AC and DC signal splitters i32A, 132B, and two filters 134A, 134B. The amplifiers 122A and 122B are amplifiers of the constant voltage control circuit 120, and therefore will not be described. The first AC/DC signal separator 132A and the second AC/DC signal separator 132B are corresponding to the first and second blood pressure signals output by the receiving amplifiers 122A and 122B, and are separated from the AC and DC components. In this embodiment, the AC and DC signals are separated. The signal separators 132A, 132B may be DC subtraction circuits whereby the DC components of the first and second blood pressure signals are filtered out. The first filter 134A and the second ferrator 134B receive the first and second blood pressure signals outputted by the AC/DC signal separators 132 and 132B, and perform filtering processing to output the signal processing circuit 13(). Wherein the first filter 134A and the second filter 134B respectively comprise a fourth order 1306024
Butterworth低通滤波器。 此較佳實施例100更包含一心電圖量測裝置，此心電圖 量測裝置係包含：兩電極片152A、152B; —第三放大器162 ; 一第三濾波器164; —第四濾波器166;以及一第四放大器 168。其中，第一電極片152A與第二電極片152B係量測心電 訊號；第三放大器162 (即儀表放大器)係接收並放大兩電極片 152A、152B所量測之訊號；而第三濾波器164與第四濾波器 166係接收並濾除第三放大器162所輸出訊號之雜訊，^中^ 第二濾波器164係可以是一兩階Butterworth高通濾、波器，而 第四滤波器166係可以是一四階Butterworth低通遽波器，以 形成一帶通濾波器；第四放大器168 (即正向放大器)係接收並 放大由上述之帶通濾波器所輸出之訊號以輸出至系統函式分 析裝置140。此外，系統函式分析裝置140所建立之複數個特 徵值係包含收縮壓、舒張壓、脈波振幅以及舒張壓間期之心週 期等資料。 凊參照第二圖，其為本發明之一較佳恒壓控制流程圖 200。步驟202係恆壓控制之開始，因此將控制旗標fjag設為 〇以表示在調控狀態中。在步驟204，接收壓力之電壓值。在 步驟206 ’檢視flag是否為1 (flag=〇，表調控狀態；丘ag=1， 表監控狀態）。當flag=0時，檢查氣囊内壓是否小於39mmHg (步驟208)，若是，則提升幫浦電壓(步驟210);若否，則檢查 氣囊内壓是否大於41 mmHg (步驟212)，若是，調降幫浦電壓 (步驟214);若否，則維持幫浦電壓並將^哗設為j以表示在 監控狀態中(步驟216)。當flag=l時，檢查氣囊内壓是否小於 35 mmHg (步驟218)，若是，將flag設為〇以表示切換至調控 狀態(步驟224);若否，檢查氣囊内壓是否大於45 mmHg (步 驟220)，若是，將flag設為〇以表示切換至調控狀態(步驟 224);若否，則維持幫浦電壓(步驟222)。藉由上述之控制將 氣囊之内壓維持在35〜45 mmHg。 1306024 請參照第三圖，其為本發明之一較佳實施例之流程圖。 在步驟302A，量測一第一量測點之一第一血壓訊號，在步驟 302B ’量測一第二量測點之一第二血壓訊號，其中步驟3〇2A、 3(^B係可同時進行。在步驟3〇4，對該第一、第二血壓訊號 ，行放大、交直流訊號分離以及雜訊濾除處理，其中，上述之 父直流巧號分離處理係將該第一、第二血壓訊號分別輸入減法 電路以，除直流訊號成分，而雜訊濾除處理係將該第一、第二 血壓訊號分別輸入兩四階Butterw〇rth低通濾波器以消除高頻 =訊。在步驟306 ’產生該第一、第二血壓訊號所對應之血壓 ’其中上述之產生該第―、第二血壓訊號所對應之血壓值， =該第-、第二1壓峨分職行數赠波處理(例如：將 2第二?二血壓訊號輸入3〇Hz八階IIR數位低通濾、波器以 iri處理），並利用查表方式輸出該第―、第二企壓訊號 值:ίί驟308 ’對該第一、第二血壓訊號進行 ί，其:建立該第一、第二血壓訊號之複數個特徵 ^測=電圖訊號，而在本實施例中，上述複數個特徵^係包 3收縮壓、舒張壓、脈波振幅以及舒張壓間期之心週期。’、Butterworth low pass filter. The preferred embodiment 100 further includes an electrocardiograph measuring device comprising: two electrode sheets 152A, 152B; a third amplifier 162; a third filter 164; a fourth filter 166; A fourth amplifier 168. The first electrode piece 152A and the second electrode piece 152B measure the ECG signal; the third amplifier 162 (ie, the instrumentation amplifier) receives and amplifies the signal measured by the two electrode pieces 152A, 152B; and the third filter The 164 and the fourth filter 166 receive and filter out the noise of the signal output by the third amplifier 162, and the second filter 164 can be a two-stage Butterworth high-pass filter and a wave filter, and the fourth filter 166 The system may be a fourth-order Butterworth low-pass chopper to form a band-pass filter; the fourth amplifier 168 (ie, the forward amplifier) receives and amplifies the signal output by the band-pass filter described above for output to the system function. Analytical device 140. In addition, the plurality of characteristic values established by the system function analyzing device 140 include data such as systolic blood pressure, diastolic blood pressure, pulse wave amplitude, and cardiac cycle of the diastolic pressure interval. Referring to the second figure, it is a preferred constant pressure control flow chart 200 of the present invention. Step 202 is the start of constant voltage control, so the control flag fjag is set to 〇 to indicate that it is in the regulation state. At step 204, a voltage value of the pressure is received. At step 206', it is checked whether flag is 1 (flag = 〇, table regulation state; hill ag = 1, table monitoring state). When flag=0, it is checked whether the internal pressure of the airbag is less than 39 mmHg (step 208), and if so, the boost voltage is raised (step 210); if not, it is checked whether the inner pressure of the airbag is greater than 41 mmHg (step 212), and if so, The pump voltage is lowered (step 214); if not, the pump voltage is maintained and set to j to indicate that it is in the monitored state (step 216). When flag=l, check whether the internal pressure of the airbag is less than 35 mmHg (step 218), and if so, set flag to 〇 to indicate switching to the regulation state (step 224); if not, check whether the air pressure inside the airbag is greater than 45 mmHg (step 220), if so, flag is set to 〇 to indicate switching to the regulation state (step 224); if not, the pump voltage is maintained (step 222). The internal pressure of the bladder was maintained at 35 to 45 mmHg by the above control. 1306024 Please refer to the third figure, which is a flow chart of a preferred embodiment of the present invention. In step 302A, measuring a first blood pressure signal of a first measurement point, and measuring a second blood pressure signal of a second measurement point in step 302B', wherein steps 3〇2A, 3(^B can be Simultaneously, in step 3〇4, the first and second blood pressure signals are amplified, AC and DC signal separation, and noise filtering processing, wherein the parent DC manual separation processing system is the first and the first The two blood pressure signals are respectively input into the subtraction circuit to remove the DC signal component, and the noise filtering process inputs the first and second blood pressure signals into the two-fourth Butterw〇rth low-pass filter respectively to eliminate the high frequency=signal. Step 306 'generate the blood pressure corresponding to the first and second blood pressure signals, wherein the blood pressure value corresponding to the first and second blood pressure signals is generated, and the number of the first and second pressures is divided. Wave processing (for example, input 2 second and second blood pressure signals into 3 Hz 8th-order IIR digital low-pass filter, and filter is processed by iri), and use the look-up table to output the first and second pressure signal values: ίί Step 308 'Using the first and second blood pressure signals ί, which: establishing the first 1. The plurality of features of the second blood pressure signal are measured = the electrogram signal, and in the embodiment, the plurality of features are the systolic blood pressure, the diastolic pressure, the pulse wave amplitude, and the cardiac cycle of the diastolic pressure interval. ',
人在此f強調的是，人體心室與主動脈的血壓除了 以杈入式1測之外，並無法以一般血壓量測裝置 =I 可在病患進行心導管手術時，同時擁取侵 與非侵入式觸血壓訊號，_這兩_^構 動脈的金管模型。病患在家或一般醫院門= 侵入式低壓型連私壓量測系統，則可以非侵人^攜式之非 Μ波形之評估’不僅提供收驗及舒張 動1 臟功能評估㈣訊，如：騎略、缝血心 反射、動脈硬化程度、射血期、增大指數等。亦&、血壓波 之阻抗心動描計法賴得的心輸出結合 :非侵入式 估心臟系統的功能。 1又八式之方式評 1306024People here emphasize that the blood pressure of the human ventricle and aorta is not measured by the intrusion type 1, and it cannot be used as a general blood pressure measuring device = I. Non-invasive touch blood pressure signal, _ these two _ ^ structure of the arterial tube model. The patient at home or general hospital door = invasive low-pressure type with private pressure measurement system, can be non-invasive and portable non-Μ waveform evaluation 'not only provides acceptance and diastolic 1 dirty function assessment (four), such as: Riding, blood stasis, arteriosclerosis, ejection duration, increase index, etc. Also combined with the heart output of the blood pressure wave impedance cardiography method: non-invasively assessing the function of the heart system. 1 and 8 styles of evaluation 1306024
以上所述僅為本發明之較佳實施例而已，並非 專利範圍；凡其他為脫離本發明所揭示之= 斤&成之4效改變或修飾，均應包含在下述之申請專利範圍 【圖式簡單說明】 第一圖係本發明之一較佳實施例之系統方塊圖； 第二圖係本發明之一較佳恆壓控制流程圖；以及 第二圖係本發明之一較佳實施例之流程圖；The above description is only for the preferred embodiment of the present invention, and is not intended to be in the scope of the patents; any other changes or modifications of the present invention which are disclosed in the present invention are included in the following claims. BRIEF DESCRIPTION OF THE DRAWINGS The first drawing is a system block diagram of a preferred embodiment of the present invention; the second drawing is a preferred constant pressure control flow chart of the present invention; and the second drawing is a preferred embodiment of the present invention. Flow chart
【主要元件符號說明】 100 一較佳實施例 112B 第二氣囊 114B 第二壓力感測器 122A 第一放大器 124 恆壓控制器 126B 第二D/A轉換器 127B 第二電流驅動器 128B 第二幫浦 132A 第一交直流訊號分 器 134A 第一濾波器 140 系統函式分析農置 152B 第一電極片 112A 第一氣囊 114A 第一壓力感測器 120 恆壓控制電路 122B 第二放大器 126A 第一 D/A轉換器 127 A 第一電流驅動器 128A 第一幫浦 130 信號處理電路 132B 第二交直流訊號分離 器 134B 第二濾波器 152A 第一電極片 162 第三放大器 1306024 . 164 第三濾波器 166 第四濾波器 168 第四放大器 200 恆壓控制流程圖 202-224 恆壓控制之操作步驟 302A、302B〜308 非侵入式連續血壓量測方法之操作步驟[Main component symbol description] 100 A preferred embodiment 112B second air bag 114B second pressure sensor 122A first amplifier 124 constant voltage controller 126B second D/A converter 127B second current driver 128B second pump 132A First AC/DC Signal Divider 134A First Filter 140 System Function Analysis Farm 152B First Electrode Sheet 112A First Air Bag 114A First Pressure Sensor 120 Constant Voltage Control Circuit 122B Second Amplifier 126A First D/ A converter 127 A first current driver 128A first pump 130 signal processing circuit 132B second AC/DC signal separator 134B second filter 152A first electrode sheet 162 third amplifier 136024 . 164 third filter 166 fourth Filter 168 Fourth Amplifier 200 Constant Voltage Control Flowchart 202-224 Operation Steps of Constant Pressure Control 302A, 302B~308 Non-invasive Continuous Blood Pressure Measurement Method
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