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
  • A61B5/022—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
  • A61B5/02208—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers using the Korotkoff method

Definitions

• the present invention aims to provide a recorder allowing the ambulatory monitoring of blood pressure, by a non-invasive, therefore non-bloody route, determining the systole, the diastole and the heart rate, by means of a measurement.
• indirect auscultation by collecting Korotkoff noises and by storing the data obtained on a solid memory.
• the device allows the immediate transfer of the recorded data to a computer, through a modem, for example present in a Minitel, and their ultra-fast processing by appropriate software, therefore practically on-line.
• the invention provides a recorder comprising a box containing all of the computer and mechanical parts, a cuff of a new model, which is fixed on an arm by enclosing it, carrying on its internal face a means of capturing noises of the systole and of the diastole and a means of capturing the air pressure existing inside the bladder, portable means for cyclically inflating and deflating the cuff, an integrated power supply source, sensor means constituted on the one hand by a piezoelectric microphone and on the other hand by a piezoresistive pressure sensor, the first listening to the sounds of Korotkoff, the second measuring the air pressure of the cuff, finally a piping necessary to pump air from the case into the cuff and an electric cable connecting the microphone and the sensor to the case.
• a device restraint system thanks to a specially suitable case and a suspension consisting of a harness and a waist belt.
• Kompelien (US Patent 3,051,165) uses a transilluminator placed at the level of the ear lobe, measuring the moment of the strongest opacity of the san ⁇ guin current and constituting the systole and that of the clarity there greater , corresponding to the lowest pressure, therefore to the diastole.
• Birnbau (US Patents 3,996,226 & 3,893,452) uses an intra-arterial catheter.
• Richter et al. (US Patent 3,187,292) integrates the first and the last sound of Korotkoff in an automatic measurement cycle.
• Follett (US Patent 3,326,230) generates pulses of low intensity repeated 'regularly' serving as calibration as spaced and regular decreases in pressure.
• Measurements are indicated by a column of lamps and can be saved by a printer. During each cycle of the operation the cuff is inflated to a determined value, then the pressure is gradually reduced through a linear leak valve (leak) separate from the blind valve (dump), used at the end of each measurement cycle .
• a linear leak valve separate from the blind valve (dump)
• his system included a series of lamps to characterize the various measurements and possibly included-
• REM SHEET a paper recorder.
• the majority of these systems have used a concept of deflating the cuff in a linear or exponentially decreasing mode with the idea of being able to correlate the measurements with the lowest heart rate, which obviously leads to fairly considerable errors of assessment, the systems used not being flexible enough to automatically adapt to variations in the heart rate, which, as is known, are frequent during the day or under various influences, such as sports, running, emotions, etc.
• the latter system
• the values of the previous arterial pressure obtained are memorized with each measurement and are taken into account for the next measurement, which is automatically incremented by a value equal to 30mm of Hg, this for the inflation pressure value.
• the transducer is placed at
• the invention relates to a certain number of devices concerning the external presentation of the recorder as well as the methods of capturing and processing Korotkoff noises.
• the technique of this collection has been perfected as well as the mechanical elements.
• the general weight and volume of the recorder are low, the shape of the device, physiologically adapted to the body.
• Pressure sensors made up of a large microphone and a transducer, are used to simultaneously monitor Korotkoff noise, oscillometric variations in the artery and air pressure in the bladder.
• the diaphragm pump, of new invoice has a small weight and size, ensuring a powerful operation and a very fast cycle, while ensuring a very low noise threshold, at the limit of the audible.
• the valve due to its original structure, perfect sealing, is particularly silent.
• the electrical source constituted by alkaline batteries with low voltage and high amperage, with a capacity approximately triple of an ordinary battery, ensures a long operating time, adapted to the number of measurements.
• the cuff has an ergonomic structure allowing very easy and quick installation and removal.
• the front side includes a piping socket for the cuff, two sockets, one for the microphone and the other for the sensor, two screens for the alphanumeric display of values, an emergency stop button and a button initialization.
• the rear side includes a multiple pin socket for Minitel, a
• REPLACEMENT on-off button two rotary switches, one for alphanumeric control, the other for the cycle interval.
• the underside has a battery lock closed by a cover.
• the housing, placed in a sheath conforming to the blank of the body, is held by a belt and by a harness, or only by one of the two.
• the latter consists of a rectangular canvas sheath, of a
• the cuff contains a bladder from which a single hose leaves, used for inflation. This is inflated to a pressure ranging from 0 to 250 mmHg. After the compressor stops operating, the microphone detects noise. If these are maintained, the microprocessor controls
• the microphone consists of a circular piezoelectric ceramic plate fixed on a very thin brass disc which acts as a membrane. The whole is fixed on a very rigid rectangular plate, which serves as support and shielding for the cell which is inside this system.
• the face of the cell which is fixed on the brass disc is earthed. On the other side of the cell, therefore on the high impedance part, the assembly is surrounded by the metallic mass. It is at this level that the tension is gathered.
• the eyelet which holds part of the printed circuit is linked to the shielding of the coaxial which brings the assembly to ground potential and which serves as shielding.
• the central wire is not connected to the shield, as this would ground it but to an isolated part of the printed circuit, an insulating relay which is itself connected to the core of the coaxial in such a way that traction on this thread is not followed by any artefactual or parasitic effect.
• the small wire starts from there and is connected to the internal face of the piezoelectric ceramic, which in this way is not subjected to any traction, any bending or any desinsertion.
• the collected voltage can reach lv, which is very important and allows all subsequent treatments.
• This voltage is transferred by an IC in an unshielded cable, of any length, along with the pressure. With an effective dimension of 35 mm on each edge, the microphone is particularly well protected against parasitic actions, such as snoring, mechanical traction on the wire, etc.
• the pressures are measured directly on the cuff using a sensor incorporated therein.
• the pressure variations of the inflation chamber are directly collected by the sensor which makes it possible to determine the oscillations and the amplitude thereof.
• the amplitude of the recorded signal may have level variations ranging from 1 volt to several tens of volts. It was advisable to carry out a filtration in a sufficiently wide bandwidth to be able to measure them in all the ranges. In fact, if the filtration is carried out at too low a level, the Korotkoff noises become inaudible and disappear. It was therefore decided to carry out this filtration at a relatively high frequency, of the order of 60 Hz, whatever the level of listening to these noises, while knowing that the resonance frequency of the microphone can be from 2000 to 3000 Hz. The reduction in noise corresponds to phase IV, therefore the decrease in frequency, which is what makes it possible to very precisely determine the appearance of the diastole.
• PULSE ACCOUNTING It includes an integrated decoder circuit (1) " , with its own control (10) and where the inputs are made in binary and where the outputs are provided in decimals. From the moment a signal appears, the system begins to count from the 3rd noise. Then the system counts up to the diastole. At the same time, square wave shaping is carried out, which makes it possible to exclude any abnormal movement that may occur during the signal pickup period. THE MOTOR. (23)
• the motor used is an ironless rotor motor, having a transmission reducer provided with a toothed belt and not a pinion.
• the reason for this substitution is that the noise level is lowered considerably and the operation of the toothed belt is smoother. In this motor there are no variations in reductance, which gives it an efficiency of almost 80%, the copper part rotating, while the iron remains fixed.
• THE VALVE 24. It constitutes one of the original parts of this invention. Instead of presenting a needle tip, it affects a cross section of a cylinder. This has the advantage of allowing a perfectly controllable air leak during deflation. It is fixed on a screw
• the pump is a diaphragm mini-pump specially built for this device, therefore very compact, but with sufficient capacity to reduce the duration of pumping at an acceptable rate. This duration is of the order of 10 seconds, for a maximum pressure of 300 mmHg. Its inflation cycle is
• Global control is ensured by means of a program stored in an EPROM memory (9), either by a separate command or by a Minitel.
• a device transforms the current from 5 volts into 21 volts for the power supply.
• Its power supply (14) includes switch-on delay circuits
• An oscillator (4) supplies the fundamental frequency of this microprocessor thanks to a Schmitt sorter, controlled by a regulator (13). 5 CLOCK, or CHUCK (8).
• Microprocessor oscillator providing the fundamental frequency of the microprocessor (Schmitt sorter).
• FIGS. 25 to 32 relate to the evolution of filtering and the clear progressive resolution of the problem of the signals of the diastole and of the system, which can be considered as the keystone of this invention.
• 28. Much more precise definition of the signals of systole and diastole. 29. Thanks to the refinement of the filtering circuits, the diastole and the systole are already very clearly defined.

Landscapes

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

Applications Claiming Priority (2)

Publications (1)

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• 1985
  • 1985-05-17 FR FR8507484A patent/FR2582122B3/fr not_active Expired
• 1986
  • 1986-05-20 EP EP19860903401 patent/EP0221981A1/de not_active Withdrawn
  • 1986-05-20 WO PCT/FR1986/000170 patent/WO1986006603A1/fr unknown
  • 1986-05-20 AU AU58163/86A patent/AU5816386A/en not_active Abandoned

Non-Patent Citations (1)

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