RU2601697C2 - Device and method for measuring human arterial pressure value - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine. Arterial pressure measuring device for human contains unit for measuring arterial pressure value, comprising pressure sensor, unit for recording deviations of arterial pressure value, equipped with optical sensor, controller, and display. Unit for measuring arterial pressure value and unit for recording deviations of arterial pressure value are combined into wrist measuring capsule. Device comprises elastic membrane, with connected thereto wrist measuring capsule. Wrist measuring capsule or controller comprises small-size air or hydraulic pump. Method for measuring arterial pressure value in human is implemented by means of device for measuring arterial pressure value, that is located on wrist of person. At that performed continuous recording of deviations of arterial pressure value from initial value, displaying excess from allowed deviation, and simultaneous accurate measurement of arterial pressure value.

EFFECT: higher efficiency is achieved of measuring arterial pressure due to expansion of functional capabilities of device with simultaneous improvement of mobility, reliability, and convenience of use, as well as accurate transmission of pulsations from radial artery to pressure sensor, and effective delivery of required air volume into wrist measuring capsule, thus providing required pressure force in order to increase accuracy of measurements.

9 cl, 7 dwg

Description

FIELD OF THE INVENTION

The present invention relates to medicine, and more particularly to tonometry. The present invention allows not only to measure a person’s blood pressure, but also to track and record sudden surges and deviations in blood pressure with instant notification to a person.

State of the art

Some people have the erroneous opinion that measuring the value of such a vital indicator as blood pressure several times a day at certain intervals (for example, once every half an hour, once an hour, etc.) is a sufficient procedure for full control over the value own blood pressure.

However, it is also extremely important to carry out constant registration of blood pressure, not only in specialized institutions (for example, in a clinic or hospital), but in any other conditions, for example, when you are at home, at work, on a walk or on a trip and etc. This is due to the fact that strong changes in blood pressure (both increase and decrease) over a short period of time can go unnoticed by a person and, as a result, pose a certain danger for him and lead to serious complications, for example, brain disorders blood circulation.

Currently, devices with a special cuff located on a person’s arm are most often used to measure blood pressure outside medical institutions (see, for example, the Wikipedia page “Blood Pressure” - http://ru.wikipedia.org/wiki/ Blood pressure). These devices take measurements at specified intervals of time - after about 15-30 minutes. However, their use to record short-term spikes in blood pressure is not possible. This is explained by both the specified interval between measurements and the duration of the measurement itself (from about 30 to 90 seconds). In this case, an algorithm for determining the average pressure value is used to determine the pressure. The maximum amplitude of the oscillations occurs at the moment when the pressure in the cuff is equal to the average pressure. Systolic and diastolic blood pressure values are derived from mean arterial pressure. In this case, the procedure for measuring pressure, namely, clamping of the brachial artery to values exceeding the systolic pressure, affects the accuracy of subsequent measurements. To exclude the indicated effect in the indicated devices, the interval between measurements should not be shorter than 5 minutes.

In addition, these devices with a special cuff are designed for use in a static position and are not suitable for constant wear on the human body.

The prior art device for measuring blood pressure of a person using a pressure sensor located on the wrist of a person (see US application for invention No. 2003/0216653 A1, publication date - November 20, 2003). However, this device, because of its size and weight, is not mobile and is intended for use, as a rule, only in special medical institutions (for example, in intensive care).

The prior art also known a device for measuring blood pressure of a person, which is also recommended for use in medical institutions, but is smaller than the above-mentioned device (see US patent for invention No. 8597195 B2, publication date - 03/03/2013 ) In addition to the pressure sensor, this device includes stepper micromotors and additional devices for fixing the hands, which greatly complicates the design and causes serious inconvenience.

In addition, a prior art device is known for measuring blood pressure of a person, which, according to the authors, was supposed to solve the problem of the impossibility of the constant use of such devices in everyday life by placing the device on the body and / or clothes of a person and making a device of several relatively small-sized ( compared with previous devices) and interconnected modules (see US patent for invention No. 8574161 B2, publication date - 11/05/2013). Nevertheless, such a design cannot provide the required degree of ease of use and mobility of the device, since it involves and thereby restricts the movement of several different parts of the human body (chest, wrist, elbow region) at once, contains connecting wires that are prone to twisting and making life difficult human, and also contains a very overall and massive circuit board. In addition, the above factors (in particular, the measurement and the location of the sensors in more than one specific area of the human body and not in one module) have a negative impact on the reliability and efficiency of the measurements due to the increased likelihood of measurement errors.

Also known from the prior art is a device for measuring human blood pressure (see US application for invention No. 2005/0228297 A1, publication date - October 13, 2005). The specified device, in General, is suitable for permanent placement on the body and / or clothing of a person with the aim of continuous registration and measurement of blood pressure. Nevertheless, the design of this device still cannot provide the necessary degree of ease of use and mobility of the device, since it involves, in addition to the wrist of a person, the index finger of a person’s hand, which leads to a serious limitation of the life of almost any person independent of his age and field of activity. In addition, measurements in various areas of the human body and the location of sensors outside a single module have a negative impact on the reliability and efficiency of measurements due to the increased likelihood of measurement errors. So, the speed of the pulse wave, which is determined by the specified device, is greatly influenced by the tone of the smooth muscles located in the wall of the arteries.

Finally, a personal monitoring system, selected as the closest analogue of the present invention, which is similar to a wristwatch, contains a controller and a display, and continuously monitors and measures a number of vital indicators of a person, including blood pressure using a sensor pressure and optical sensor (see US application for invention No. 2014/0143064 A1, publication date - 05/22/2014). However, the system according to the closest analogue cannot fully ensure the reliability and effectiveness of the measurements due to the inability to select the exact location of the projection of the radial artery on the human skin and fixation at this point in the system, which leads to measurement errors (for accurate measurement, it is necessary that the radiation the artery at the time of measurement lay on the radius). In addition, the system according to the closest analogue requires refinement in terms of a more accurate transmission of pulsations from the radial artery to the pressure sensor and in terms of providing better pressure to the human skin, which is also necessary to increase the measurement efficiency.

Disclosure of invention

An object of the present invention is to provide such a device and method for measuring a person’s blood pressure, in which it would be possible to register deviations of a blood pressure value and indicate it to a person, after which an accurate measurement of blood pressure would be performed.

The technical result of the present invention is to increase the efficiency of measuring a person’s blood pressure by expanding the functionality of devices for measuring a person’s blood pressure while increasing their degree of mobility, reliability and ease of use.

To achieve the above technical result, there is provided a device for measuring a person’s blood pressure, including a blood pressure measuring unit, comprising a pressure sensor, a blood pressure deviation recording unit provided with an optical sensor, a controller and a display, and a blood pressure measuring unit and a deviation recording unit blood pressure values are combined in the carpal measuring capsule, and it contains an elastic membrane y and carpal measuring capsule is connected to the elastic membrane, the measuring capsule or carpal controller comprises a small-sized air or hydraulic pump.

The carpal measuring capsule can be made in the form of a disk connected to the pipe at one end of the pipe.

The carpal measuring capsule can be connected to the elastic membrane via an o-ring.

A small air or hydraulic pump can be connected to the nozzle at the other end of the nozzle.

The unit for detecting deviations in blood pressure may include a light and / or sound indicator.

The optical sensor may include an optocoupler comprising at least one LED or a laser diode with a lens, a photodetector with a lens, an aperture and a screen.

A device for measuring a person’s blood pressure can be connected to a mobile device made in the form of a mobile phone, smartphone, tablet computer, laptop or desktop computer.

Also, to achieve the above technical result, a method for measuring a person’s blood pressure by means of the above-mentioned device for measuring a person’s blood pressure is provided, which consists in continuously recording deviations of a blood pressure value from an initial value, indicating an excess of an allowable deviation, and simultaneously measuring an exact value of blood pressure.

According to the method, as deviations of the blood pressure value, an increase and decrease in the pressure value from the initial value can be recorded.

Brief Description of the Drawings

The present invention is illustrated by the following drawings:

FIG. 1 is an external view of a device in accordance with the present invention;

FIG. 2 is a schematic diagram of parts of a device in accordance with the present invention;

FIG. 3 is a layout diagram of a measuring capsule in accordance with the present invention;

FIG. 4 is a schematic illustration of a measuring capsule in accordance with the present invention;

FIG. 5 is a schematic illustration of a measuring capsule with an optical sensor installed;

FIG. 6 - volumetric image of the measuring capsule;

FIG. 7 is a diagram for determining systolic and mean pressure.

The implementation of the invention

A device for measuring a person’s blood pressure is similar to a wristwatch (see Figure 1) and consists of a unit 1 for recording deviations in the value of blood pressure and a unit 2 for measuring blood pressure, both of which are located on the wrist of a person, attached to it using a bracelet or belt 4 and combined into a measuring capsule 6 with the skeleton of a 6 ′ capsule. The measuring capsule 6 may be made of material with moderate ductility.

Block 1 registration of deviations in blood pressure is equipped with an optical sensor. Block 2 for measuring blood pressure contains a pressure sensor. The pressure sensor can be a digital pressure sensor with a resolution of 16 digits and an SPI interface. In this case, the pressure sensor is used only to determine the pressure in the measuring capsule 6, and the optical sensor registers a pulse wave from the skin surface in the projection area of the radial artery 10 (see Figure 2). The device for measuring a person’s blood pressure contains a controller 5 (see Figure 2) and a display 3 (see Figure 1). In a preferred embodiment of the present invention, the display 3 may be an OLED display with a resolution of 92 x 128 pixels.

The task of the pressure sensor is to monitor the pressure in the measuring capsule 6. In this case, the optical sensor registers the pulse volume waves. The collected pulse waves are analyzed by amplitude and waveform. The Figure 7 schematically shows the interaction of the pressure sensor and the optical sensor. The optical sensor detects the appearance of the first pulse wave - point T1, the pressure sensor detects the pressure in the measuring capsule 6, and this value corresponds to the value of systolic pressure. Further, the pressure in the capsule continues to decrease, and at the point T2, which is determined by the shape of the pulse wave (the smoothed portion of the wave disappears), the average pressure value is determined.

In Figure 7, position 20 denotes the pressure in the measuring capsule, position 21 denotes systolic pressure, position 22 denotes the average pressure, position 23 denotes the pressure in the artery, position 24 denotes the smoothed part of the wave, position 25 denotes pulse wave patterns.

The device for measuring a person’s blood pressure also comprises an elastic membrane 7, and a measuring capsule 6 is connected to the elastic membrane 7 by means of an o-ring 8 (see Figures 2-4).

The Figure 2 also illustrates the main elements of the human hand, involved and / or located in close proximity to the operation of the inventive device: skin 9, radial artery 10 and radial bone 11.

The Figure 3 illustrates the location and fixation of the measuring capsule 6 above the projection site of the radial artery 10.

The measuring capsule 6 is made in the form of a disk, connected to the pipe 12 from one end of the pipe (see Figure 4).

The measuring capsule 6 or controller 5 contains a small-sized pump (not shown in the drawings) connected to a pipe 12 from the other end of the pipe 12. A small-sized pump (or micropump) sets the required pressure from 0 to 300 mm Hg. A small-sized pump is installed in a bracelet or belt 4 of the inventive device. A small-sized pump may contain a piezoelectric pump with a pressure of at least 0.33 bar. In the inventive device can be used any known types of small-sized pumps, including air or hydraulic (liquid).

Block 1 registration of deviations in blood pressure contains a light and / or sound indicator.

The optical sensor comprises an optocoupler comprising at least one LED 13 or a laser diode with a lens 14, a photodetector 15 with a lens 14 ′, an aperture 16 and a screen 17 (see Figure 5). Also in figure 5, the numeral 18 denotes the light from the source, and the numeral 19 is the diffused light. LED 13 or a laser diode operates in the near infrared region of the spectrum (800-900 nm). The optimal radiation wavelength of 810 nm corresponds to the isobestic absorption point of hemoglobin (this choice is due to the fact that the saturation of hemoglobin with oxygen can affect the amplitude of the pulse wave). At a given wavelength, the molar extinction coefficients of oxy- (HbO ₂ ) and deoxyhemoglobin (Hb) are equal (the oxygenated form of hemoglobin is called oxyhemoglobin; the oxygen that has given up to tissues is called deoxyhemoglobin, and this ratio of hemoglobin forms in humans can change). At a certain point in the spectrum of 810 nm, the molar extinction (absorption) coefficients of these two forms are the same. This choice of wavelength eliminates the influence of the saturation state of hemoglobin on the amplitude characteristics of the recorded pulse wave.

Figure 5 shows the design of an optical sensor consisting of a single LED 13 (emitter) and a photodetector 15. A lens 14 is mounted on the LED 13, which forms a spot of light on the skin surface of a given size. The photodetector 15 is surrounded by a screen 17 with an aperture 16, which allows to reduce spurious illumination and to register only backscattered light from the region of interest (the site of projection of the radial artery 10). However, to simplify the installation of the measuring capsule 6 on the projection area of the radial artery 10, an array of photodetectors and LEDs (emitters) can be used. Using the multiplexing procedure, the optocouplers are polled in turn and the one with which the maximum signal is recorded is selected. This approach greatly simplifies the procedure of "aiming" of the measuring capsule 6 over a given surface. The pressure sensor that records the pressure in the measuring capsule 6 can be installed directly in the measuring capsule or can be taken out into the compartment of the controller unit 5.

The inventive device can be equipped with an accelerometer with an SPI interface, which is used to record a state of rest, in which the measurement results can be considered reliable. Also, the inventive device can be equipped with a battery, which can be a lithium-polymer capacity of 140 ÷ 180 mA or 480 mA with continuous operation for at least 24 hours. In addition, the inventive device can be equipped with an electrocardiograph.

The use of a signal to determine the pressure using an optical sensor, compared with the use of a signal received from a pressure sensor, has significant advantages. So, when measuring pressure using a pressure sensor (without using an optical sensor), only the average blood pressure value is determined, which corresponds to the maximum signal amplitude. In this case, the values of systolic and diastolic pressure are calculated values. Various manufacturers of automatic blood pressure monitors use their own pressure determination algorithms. So, for example, systolic pressure can be determined by the amplitude of the oscillations, equal to 0.8 of the maximum amplitude on the ascending arm, registered oscillations. In this case, diastolic pressure can be determined, for example, by the amplitude of the oscillations equal to 0.5 of the maximum on the descending shoulder. Until now, the standard for measuring blood pressure has been the recording of Korotkov tones (auscultation method).

It is necessary to emphasize the extreme importance of accurately determining the mean pressure from the maximum amplitude of the oscillations. The maximum amplitude of the oscillations occurs at the moment when the pressure in the cuff is equal to the average pressure. Signal registration by an optical sensor allows you to determine the value of systolic and average pressure. In this case, the diastolic pressure is uniquely determined by calculation on the basis that the average pressure is equal to the sum of the diastolic pressure plus one third of the pulse pressure (pulse pressure is the difference between the values of systolic and diastolic pressure). Unambiguously determine the value of systolic pressure is possible only when using an optical sensor. The average pressure values are determined using both a pressure sensor and an optical sensor.

The impossibility of directly determining the value of systolic pressure using a pressure sensor is determined by the fact that pulse pressure waves coming from the proximal side of the capsule location are recorded even at a pressure higher than systolic (suprasystolic waves). Whereas the appearance of a pulse volume wave recorded by an optical sensor unambiguously indicates the magnitude of systolic pressure.

With continuous registration in the measuring capsule 6, pressure is created in the diastolic region, after which a continuous analysis of the pulse wave shape takes place and the trend is analyzed (increase, decrease in blood pressure). If the specified threshold is exceeded (increase or decrease in pressure by 20 mmHg), an audible signal sounds and a complete pressure measurement takes place. Complete pressure measurement means the process of recording both the systolic and mean pressure values. In the continuous monitoring mode, a continuous analysis of the shape of the pulse wave occurs at a pressure in the measuring capsule 6 below the value of the diastolic pressure (in Fig. 7, the pulse waves are on the extreme right). At this pressure in the measuring capsule 6, the person does not compress the artery.

A device for measuring a person’s blood pressure is connected to a mobile device (not shown in the drawings) made in the form of a mobile phone, smartphone, tablet computer, laptop or desktop computer. In this case, both blocks 1, 2 have the ability to transmit a signal to a mobile device.

A method of measuring a person’s blood pressure is as follows.

1. The device is mounted on the wrist area.

2. The registration of pulse volume waves by an optical sensor is started, while the pressure in the measuring capsule is recorded.

3. Determined systolic and average pressure.

4. The diastolic pressure is calculated.

5. Transition to the monitoring mode. In this case, continuous registration and registration is assumed after a predetermined time interval (10 minutes).

6. With continuous registration in the capsule, pressure is created in the diastolic region, after which there is a continuous analysis of the pulse wave shape and the trend is analyzed (increase, decrease in blood pressure). If the specified threshold is exceeded (increase or decrease in pressure by 20 mmHg), an audible signal sounds and a complete pressure measurement takes place.

7. All data from the device is transferred to the mobile device and stored on it.

8. The mobile device transmits the accumulated data to the "cloud" (cloud data storage), which can be accessed by relatives and the doctor.

The inventive method also implies the possibility of performing multiple calibrations of the device. For this, a full cycle of the oscillometric measurement of blood pressure is carried out, the results of which are transmitted to the controller. Then, the claimed device conducts a cycle of measuring the propagation time of the pulse wave, correlating the result in the internal index table with the results of measuring blood pressure. After that, the settings are synchronized over the ranges of critical parameters. These settings can be set or changed by the user.

Claims (9)

1. A device for measuring a person’s blood pressure, including a blood pressure measuring unit, comprising a pressure sensor, a blood pressure deviation recording unit provided with an optical sensor, a controller and a display, the blood pressure measuring unit and a blood pressure deviation recording unit being combined in the carpal measuring capsule, characterized in that it contains an elastic membrane, and the carpal measuring capsule is connected to astichnoy membrane, wherein the measuring capsule or carpal controller comprises a small-sized air or hydraulic pump. 2. The device according to p. 1, characterized in that the carpal measuring capsule is made in the form of a disk connected to the pipe. 3. The device according to claim 1, characterized in that the carpal measuring capsule is connected to the elastic membrane by means of an o-ring. 4. The device according to p. 1, characterized in that the small-sized air or hydraulic pump is connected to the pipe. 5. The device according to claim 1, characterized in that the unit for registering deviations in the value of blood pressure contains a light and / or sound indicator. 6. The device according to claim 1, characterized in that the optical sensor comprises an optocoupler comprising at least one LED or a laser diode with a lens, a photodetector with a lens, an aperture and a screen. 7. The device according to p. 1, characterized in that it is connected with a mobile device made in the form of a mobile phone, smartphone, tablet computer, laptop or desktop computer. 8. A method of measuring a person’s blood pressure, including continuously recording deviations of the blood pressure from the original value, an indication of the excess of the permissible deviation, and simultaneously measuring the exact value of the blood pressure, characterized in that the device according to any one of paragraphs. 1-7, while placing it on the wrist of a person. 9. The method according to p. 8, characterized in that as deviations of the blood pressure value, an increase and decrease in the pressure value from the initial value is recorded.

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