Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
  • A61B5/021—Measuring pressure in heart or blood vessels
  • A61B5/02108—Measuring pressure in heart or blood vessels from analysis of pulse wave characteristics
  • A61B5/02125—Measuring pressure in heart or blood vessels from analysis of pulse wave characteristics of pulse wave propagation time
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
  • A61B5/021—Measuring pressure in heart or blood vessels
  • A61B5/022—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
  • A61B5/0225—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds
  • A61B5/02255—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds the pressure being controlled by plethysmographic signals, e.g. derived from optical sensors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
  • A61B5/026—Measuring blood flow
  • A61B5/0285—Measuring or recording phase velocity of blood waves
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
  • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
  • A61B5/6813—Specially adapted to be attached to a specific body part
  • A61B5/6814—Head
  • A61B5/6815—Ear
  • A61B5/6816—Ear lobe
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
  • A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
  • A61B5/7207—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts
  • A61B5/7214—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths

Definitions

• the invention relates to a method for the continuous, non-invasive measurement of blood pressure in humans.
• the pulse swell speed allows a certain access to blood pressure.
• PWL pulse wave velocity or pulse wave transit time
• the transit time of the pulse wave caused by each heartbeat is measured, either using the time difference between the R wave of the electrocardiogram (EKG) and the arrival of the pulse at a peripheral artery measures or the time difference between two different distal pulses via mechanical or optical Sensor recorded.
• the thus determined pulse transit time correlates intraindi vidually high with average Blutdruckwer ⁇ th.
• the Hauptnachtei of this method is that a measurement of the separated ge ⁇ di Astol regard and systolic pressures is in principle not possible.
• ear pulse measuring devices which only determine the changes in the amount of blood on the earlobe fluctuating with the pulse in a photoelectrical manner, qualitatively and roughly, so-called ear pulse measuring devices (OPM). These devices, which have been known in principle for a long time, only serve to determine the pulse frequency.
• OPM ear pulse measuring devices
• the object of the invention is therefore to provide a blood pressure measuring method with which the blood pressure can be measured continuously and without blood with the required accuracy, in particular the systolic, diastolic and mean blood pressure.
• Another object of the invention is to avoid the above-mentioned disadvantages of the known measuring devices based on the RR method.
• the problem of sensitivity to movement artifacts should also be solved. This object is achieved essentially by the method defined in claim 1.
• Blood volume density in the sense of the present invention is to be understood as the blood volume per unit volume of tissue in a body tissue with a dense blood vessel network (e.g. earlobe) that changes periodically with the pulse rate and is influenced by the body's own regulations.
• a dense blood vessel network e.g. earlobe
• the main advantages of the invention are that a continuous, non-invasive blood pressure measurement is possible not only in the clinic, but also in the everyday environment, even in the state of the head, that the sensors, namely ear clip and EKG, electrodes for Patien ⁇ th too vernachl ssigende physical impairment represent that the measuring system easily portable on the body is because it is very small and light that the system has reduced to a 'minimum susceptibility to motion artifacts, because not is measured on a single artery and that the measuring system is considerably cheaper to produce than systems according to the prior art.
• all pulse-registering measuring systems can be used as the ear pulse measuring device sensor for determining the arterial blood volume density proportional to the blood pressure, in which a measuring signal taken from the earlobe is proportional to the blood volume density and / or the blood pressure.
• a suitable miniature microphone is used instead of the EKG electrode, which is attached with an adhesive strip over the heart. The microphone then serves to determine the systole (first heart tone).
• a particularly preferred further development of the invention can also include an LED and photodiode to be attached to certain areas of the chest or back near the heart Use sensor.
• the light of the LED is scattered on the fine blood vessel network, the scattered light is registered by the photodiode, and thus the exact time at which the pulse wave passes the sensor. It is crucial that the area of skin on which the sensor is attached is supplied with blood from an intercostal artery as close as possible to the heart.
• the location on the chest or back should be selected, taking into account the anatomical course of the vessel, so that the duration of the pulse wave from the heart to the sensor close to the heart is minimized, thus maximizing the time difference between the pulse wave between the sensor near the heart and the ear pulse sensor.
• This preferred embodiment is particularly precise and is not particularly prone to failure.
• 1 is a graphical representation of the time course of the output signal of the ear pulse measuring device of the blood pressure measuring device operating according to the method according to the invention
• FIG. 2 shows a schematic illustration of the blood pressure measuring device operating according to the method according to the invention
• FIG 3 shows a section through the ear clip of the blood pressure measuring device according to the invention in a semi-schematic representation.
• the ear pulse measuring device sensor is clamped or additionally glued to the earlobe with an ear clip.
• the ear pulse measuring device sensor fulfills a double function: a small light source with a suitable wavelength shines through the earlobe.
• the transmission of the earlobe which varies proportionally with the blood pressure, is measured by a photodiode.
• the arrival of the pulse wave at the earlobe registered relative to the systole by the EKG signal, can also be seen directly from the transmission timing. This determines the pulse wave transit time for the heart / earlobe segment.
• FIG. 1 shows schematically the course of the photocurrent i (t) on the ear pulse measuring device photodiode, the light source in this example being a pulsed (infrared) light-emitting diode.
• the associated blood pressure values are shown on the right edge of the figure (mean p, systolic p gratuitand di astolic pressure p.).
• the second independent blood pressure value is determined as follows with the aid of the photocurrent curve of the ear pulse measuring device.
• i can be assigned to ⁇ p, ie the photocurrent curve can be converted into blood pressure values for a limited period of time (at least for a few seconds) and at the same time the blood pressure scale (Fig. 1 on the right) can be permanently changed Zero point establish.
• signal changes .DELTA.i can typically be caused firstly by blood pressure-proportional pulse-synchronous vasodilatation and secondly by slow vasomotor and other changes in the amount of C-apillaries through which flow occurs.
• FIG. 2 illustrates the structure of the blood pressure measuring system, wherein one can be content with a sketch of the signal paths between the components and details can be left to the person skilled in the art.
• the ear pulse measuring device 10 in FIG. 1 sketched signal i (t) in the analogue digital wall! he 12.
• the digitized signal goes for processing in the microcomputer 14.
• the AD converter 12 receives control signals from the microcomputer 14.
• the microcomputer 14 also controls all signals emanating from the ear pulse measuring device 10.
• the signals from the reference sensor 16 for detecting the start of the pulse wave go directly to the microcomputer 14.
• the sample-specific calibration curve is input to the microcomputer 14 via the line 18 and the calibration curve is in the micro ⁇ computer 14 stored (in Fig. 2, the case was chosen that the pulse wave transit time was determined as a function of p r m).
• This calibration curve is used by the microcomputer for the ongoing conversion of the pulse wave transit times into the respectively selected blood pressure size.
• a further task of the microcomputer 14 is sketched in FIG. 2, namely the automatic re-calibration of the photocurrent curve in blood pressure values at 20.
• FIG. 3 An exemplary embodiment of an ear pulse measuring device sensor in the form of an ear clip is shown in section in FIG. 3.
• 1 denotes an LED
• 2 a photodiode
• 3 an integrated temperature sensor.
• the clamped ear clip is well fixed on both sides of the earlobe 5 with the help of ring-shaped adhesive strips 4.
• the temperature sensor 3 is in skin contact with the earlobe. The temperature measurement is used for the additional control of changes in the blood volume density of the earlobe, which have to be continuously monitored as described.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Cardiology (AREA)
• Heart & Thoracic Surgery (AREA)
• Molecular Biology (AREA)
• Veterinary Medicine (AREA)
• Biophysics (AREA)
• Pathology (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Public Health (AREA)
• Medical Informatics (AREA)
• Physics & Mathematics (AREA)
• Surgery (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Physiology (AREA)
• Vascular Medicine (AREA)
• Hematology (AREA)
• Otolaryngology (AREA)
• Ophthalmology & Optometry (AREA)
• Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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• 1988
  • 1988-03-09 DE DE3807672A patent/DE3807672A1/de active Granted
• 1989
  • 1989-03-09 JP JP1502923A patent/JPH03505533A/ja active Pending
  • 1989-03-09 WO PCT/DE1989/000152 patent/WO1989008424A1/de not_active Application Discontinuation
  • 1989-03-09 EP EP89903093A patent/EP0403522A1/de not_active Withdrawn
  • 1989-03-09 US US07/576,404 patent/US5237997A/en not_active Expired - Fee Related

Non-Patent Citations (1)

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