RU2200463C2 - Device for performing physiological function monitoring - Google Patents

Abstract

FIELD: medical engineering. SUBSTANCE: device has stable electric current generator, micro- processor with liquid crystal display unit, biotelemetry unit, alarm signalization unit, units for measuring electrocardiogram, IPG and temperature, three control busses, two master and five receiving electrodes fastened on patient corps, two main busses joined in a way that the stable electric current generator is connected with its outputs to the first and the second master electrodes. The first, the second and the third receiving electrodes are connected to units for measuring electrocardiogram, IPG via the first main buss, the fourth and the fifth receiving electrodes are connected to unit for measuring temperature also via the first main buss. Outputs of all mentioned units are connected to information inputs of the micro-processor via the second main buss. The first buss for controlling the micro- processor is connected to control input of the stable electric current generator, the second one to the alarm signalization unit and the third one to biotelemetry unit. Micro-processor output is connected to the stable electric current generator via on/off buss. EFFECT: wide range of functional applications. 10 cl 7 dwg

Description

 The invention relates to medical equipment and can be used for monitor tracking the patient’s body temperature, heart rate (HR), respiratory rate (BH). It can also be used to issue an alarm when registering (exceeding) certain physiological data of the user.

 A personal device for monitoring physiological functions is known, see US patent 4509531, in which an apparatus for monitoring the physiological functions of a user has a casing with an electrically conductive underlying surface that provides electrical contact with the surface of the user's body. An opening is provided in the underlying surface of the casing. A temperature sensor is mounted in the casing, generating a signal, which is an indication of the user's temperature. The device has an electrically and thermally conductive cap through which a temperature sensor is inserted into the casing. To fix the cap in the hole of the underlying surface of the casing, a holder is provided by which the cap is held in electrical and thermal contact with the surface of the user's body and is electrically and thermally isolated from the underlying surface of the casing. For electrical connection with a temperature sensor and a cap, special elements are provided. A device generating a signal, which is an indication of the galvanic resistance of the user's skin, is electrically connected to the underlying surface of the casing and the cap. The apparatus includes an alarm system that receives signals from a temperature sensor and a device for indicating the resistance of the skin of the user. The system generates alarms when registering certain physiological user data.

 The disadvantage of this device is the design complexity and the small number of functions performed, so it does not measure BH and heart rate.

 Known portable physiological monitor, see International application 88/05282, PCT (WO), publication of 88.07.28, this monitor contains multifunctional electrodes arranged in a flat triangular configuration. These electrodes detect information about ECG, sound, temperature and conductivity, which is processed by the monitor and displayed on the display in real time in the form of an analog ECG curve, digital data on heart rate, temperature and respiratory rate, as well as in the form of voice through a loudspeaker. A portable monitor applied to the chest allows medical personnel to receive real-time information about vital signs of a patient at a glance.

 The disadvantage of this monitor with all its multifunctional capabilities is the inconvenience of use, because it is made in the form of a box applied to the chest, which requires continuous monitoring by medical personnel, because the indication is rather inconvenient, in addition, it cannot be used when the patient is moving, there is no connection with the central monitor.

 A known system for monitoring temperature monitoring of the patient’s body and its heart rate, see US patent 4686998, RJ Bioengineering. 68, M., 1988. The system includes a portable battery-powered transmitter to which two electrodes are connected. The 1st electrode is a thermistor and is attached to the skin of the axillary artery. The 2nd electrode is mounted on the 4th intercostal space. The receiver includes a modulation unit and a microprocessor device for digitally indicating the patient's body temperature and heart rate. The microprocessor allows you to compare the received signals with threshold values and to issue alarms if necessary - PROTOTYPE.

 The disadvantages of the prototype are insufficient functionality, so the system cannot be used when the user is moving and has no connection with the central monitor (post).

An object of the invention is the expansion of functionality and ease of use due to:
- removal of the impedance pneumogram (IPG);
- temperature removal;
- taking an electrocardiogram (ECG) and heart rate (heart rate);
- constructing the construct in such a way that it is possible to take off all the characteristics, both at rest and in motion, display them on the front panel and transmit them via radio and / or optical biotelemetry channels, also transmit them to the central monitoring console;
- introduction of remote control.

 The specified goal is achieved as follows. A device for monitoring physiological functions, comprising a microprocessor with an LCD display for digital indication of body temperature and heart rate, the first and second electrodes and an alarm block, characterized in that a stable current generator, ECG and IPG measuring units, three control buses are inserted into it five receiving electrodes located on the patient’s torso, and two information lines with the following connections: a stable current generator is connected by its outputs to the first and second master electrodes, the first, second and three s receiver electrodes through the first information line connected to the ECG measuring units and IPG, fourth and fifth receiving electrodes are connected to a temperature measuring unit and via a first information line, the outputs of all of said blocks are connected to the data inputs of the MP through the second information highway; the first MP control bus is connected to the control input of the stable current generator, the second bus is connected to the alarm block, the third bus is to the biotelemetry unit, the MP output on / off is also connected to the stable current generator; structurally, the device is made in a wearable version in the form of a rectangular box of dielectric material, for example, of impact-resistant polystyrene, 150x75x20 mm in size, which is attached to the patient: either on a waist belt, or in a pocket, or on the body with "Velcro", and one big side the boxes are not functionally involved, and on the other there is an LCD display and an antenna for radio and / or biotelemetry, for example, in the form of a radiating LED, from one end of the box at the ends of flexible terminals ≈1.5 m long are fixed, for example, with schyu connector defining two and five reception electrodes arranged as follows: the first drive, the first and fourth receiving electrodes on a single hard dielectric base, defining a second, second and fifth receiving electrodes on another hard dielectric base and a separate third receiver electrode; The ECG unit contains the first and second receiving electrodes, a differential operational amplifier, an integrator, a scaling amplifier and a notch filter connected as follows: the first and second receiving electrodes are connected to the direct and inverse inputs of a differential operational amplifier, the output of which is connected through a scaling operational amplifier and a notch filter through the second information highway with information inputs of the microprocessor "f", the output of the differential operational amplifier through int the actuator is additionally connected to its control input; The IPG block contains the first, second and third receiving electrodes, the first, second and third operational amplifiers, the first, second and third synchronous rectifiers connected as follows: the receiving electrodes are connected in pairs with the inputs of three operational amplifiers connected in differential mode, the outputs of which are synchronous rectifiers and a second information highway are connected to the microprocessor information inputs “h”; the temperature measuring unit contains the fourth and fifth receiving electrodes, the first and second Schmidt triggers, the fourth and fifth electrodes being connected to the inputs of the first and second Schmidt triggers, respectively, the outputs of the Schmidt triggers of the temperature measuring unit through the second information line are connected to the information inputs "g" of the microprocessor; the fourth and fifth receiving electrodes are small-sized temperature sensors based on piezoelectric cutoff elements in a flat ceramic or glass case measuring 2.3 x 14 mm; the first and second master electrodes, the first, second and third receiving electrodes are made in the form of disks with a diameter of 3-15 mm and a thickness of 0.4-0.8 mm, made of non-oxidizing material, such as tin, and located as follows: first master, first and the fourth receiving electrodes on one rigid dielectric base on the left side of the torso, the second master, the second and fifth receiving electrodes on the hard dielectric base on the right side of the torso, the distance between the first (second) master and the first (second) receiving electrode ohm on each part of the torso lies within 3-5 disc diameters, and the third electrode is mounted at the base of the larynx or lower, up to the diaphragm; either the thermistor or the pn junction of the diode or transistor are used as the fourth and fifth receiving electrodes; the first information highway is made in the form of a common flexible electrode cable, the number of signal cores of which corresponds to the number of master and receiving electrodes; also contains a remote control channel.

 In FIG. 1 shows a structural electrical diagram of a device for monitoring physiological functions, FIG. 4 is a structural electrical diagram of an IPG impedance pneumogram removal, FIG. 3 is a temperature measurement, FIG. 2 is an ECG measurement, which shows: 1 - a stable current generator ( GTS), 2 - a microprocessor with an LCD display (MP), 3 - a biotelemetry unit, 4 - an alarm block (light and / or sound), 5 - an ECG removal unit, 6 - a temperature measurement unit, 7 - an IPG removal unit, 8 - power supply, 9 - patient, ZEL1 and ZEL2 - master electrodes, PEL1 ... PEL5 - receiving electrodes, the first, second and third busbars of the board, M1 and M2 - the first and second information lines, f, g and h - information inputs of the MP, 10 - differential measuring operational amplifier (OA), 11 - integrator (integrating OA), 12 - scaling op-amp, 13, 14 and 15 - operational amplifiers in differential switching, 16 - notch (blocking) filter at a frequency of 50 Hz (60 Hz), 17, 18 and 19 - synchronous rectifiers, 20 and 21 - Schmidt triggers, A - antennas of the radio and / or biotelemetry unit, on / off - generator enable bus 1, RS-232C - serial and terfeysa.

 The first and second outputs of stable current generator 1 are connected to ZEL1 and ZEL2, respectively, PEL1, PEL2 and PEL3 are connected to ECG 5 and IPG 7 through the first information highway M1, PEL4 and PEL5 are connected to temperature measuring unit 6 also through the same bus, the outputs of these blocks through the second information highway M2 are connected to the information inputs g, h, f, respectively, of the microprocessor 2, which is connected by the first control bus to the control input of the generator 1, the second control bus to the alarm unit 4, and the third control bus to Locke biotelemetry bus 3 and on / off switch - with the enabling input of the generator 1, the serial bus is an additional output device for communication with the central computer (if necessary), and LCD display - major, entering the device are electrodes defining ZEL1 and ZEL2.

 These nodes and blocks can be performed on the following elements.

 Schmidt trigger 20 and 21 on the IMS 564 series (CMOS) type 564TL1, see the catalog "Sector of electronic components", Russia-99, M .: DODEKA, 1999, p. 78; the alarm block (alarm block 4) is in the simplest case a dynamic loudspeaker interfaced with MP 2, and its sound (tone, volume, frequency) is programmed at the request of the customer in the same MP 2; the light signaling of this unit is in the simplest case a separate sector of the LCD display, which in the event of an alarm starts flashing from minimum to maximum glow with a frequency of, for example, 2 Hz; power supply 8 is a stabilized source that has two inputs: from ~ 220 V / 50 Hz or from an autonomous battery, can be performed according to any standard scheme, security group 2; OU10-OU15 - operational amplifiers, for example, on domestic IC series 140; MP 2, for example, on IC PIC 16C74 from MICRO-CHIP; notch filter 16 can be performed in bulk on passive ERE with op-amp; synchronous rectifiers 17-19 can be made, see R. Graf. Electronic circuits. M .: MIR, 1989, p.198; master oscillator 1 - see R. Graf. Electronic circuits. M: WORLD, 1989, p. 162; LCD display - see catalog 96/97, Setron, p. 466, 38032, Branshweig, Cermany.

 PL4 and PL5 are a tuning fork small-sized thermo-quartz sensor, for example, type GT3500 from ETA (Switzerland), see V.V. Malov. Piezoresonance sensors. M.: Energoatomizdat, 1989, p. 112-113, or a well-known IC type TM04 from Analog Devices company with a digital PWM output and a sensor in the form of a p-n junction.

 A device for monitoring physiological functions works as follows. Consider the example of power from an internal battery. The monitoring construct (box) is attached to the patient 9, for example, to the waist belt, the master and receiving electrodes are fixed to the torso of the patient 9 according to FIG. 1 or at other points at the doctor’s request (requirement), you can attach the electrodes to the torso, for example, with Velcro. The construct is mounted with a flat base to the patient’s body, and the LCD display, respectively, to the outside. After that, the construct is included in the work with the electrode connector, for which a special jumper (not conventionally shown in the diagram) is soldered into it, which allows the passage of power to the electronic part of the circuit. When the power supply MP 2 conducts the actual zeroing mode, self-monitoring, etc., i.e. everything that is inherent in this particular type of MP. After that, a enable signal (supply of output signals output1 and output2) of the generator 1 to the driving electrodes ZEL1 and ZEL2 comes on the on / off bus. The frequency and output current of generator 1 are determined in advance, but can be changed (set) according to a certain algorithm from MP 2 via control bus 1. After that, the measurement mode of physiological functions begins.

The temperature measurement mode (figure 3). In this mode, the fourth and fifth receiving electrodes PEL4 and PEL5 work, which change the frequency of self-generation (primary frequency 256 kHz) depending on the change in the patient’s body temperature. The output voltage of the frequency of the sensors is the frequency sequence of pulses with a duration of 1-3 μs. Within plus 30-50 ^o C, the sensors have an almost linear characteristic, and the measurement error is not worse than 0.1 ^o C.

 The sensor has a frequency division circuit inside, so the output pulses follow a frequency of 1 kHz with a temperature-dependent deviation. Time constant not higher than 0.5 s. The measured patient temperature at two points (PEL4 and PEL5) in the form of two frequency sequences along the first information highway M1 (buses "a" and "e", respectively) is sent to block 6, where through Schmidt triggers 20 and 21 (for "twisting" the fronts ) then it passes through the second information highway M2 to the information inputs “g” of MP 2, in which the frequency sequences are converted to voltages, averaged (the arithmetic mean value is taken), and displayed on the LCD in digital form in the usual format for all in degrees elsiya.

The measurement mode ING (figure 4). In this mode, the driving electrodes ZEL1 and ZEL2 and the associated receiving electrodes PEL1 and PEL2 and a separate receiving electrode PEL3 work. In this mode, conductivity is continuously measured between all three receiving electrodes. For this, the signals of all three receiving electrodes through the first information highway M1 (buses "d", "c", "c") are sent to the ECG5 measuring unit, where they are sent in pairs to the operational amplifiers OU13, OU14 and OU15, which are switched on in differential mode. The output of each op-amp is connected to the corresponding synchronous rectifier 17, 18 and 19, respectively, whose reference voltages coming from the generator 1 (output1 and output2) are not conventionally shown in the diagram. At the moment of the beginning of the attempt of inhalation, changes in conductivity occur, which is determined by one of the three op-amps (or two or all), then after synchronous rectification (if the signal exceeds a certain value) in the form of a log.1 appears "signal of the left lung", or "signal of the right lung ", or the" summing signal of both lungs ", or all three, which are fed through the second information line M2 to the information inputs" h "of MP 2, which processes them and lights up on the LCD. Function IPG has the following indicative form (figure 5), where:
1, 3, 5, 7, 9, 11 - maximum points of extremum;
2, 4, 6, 8, 10, 12 - minimum extremum points
From FIG. Figure 5 shows that the breathing amplitude is large (up to 40 dV), therefore, synchronous rectifiers 17, 18 and 19 simultaneously serve as limiters, after which MP 2 reads the number of extrema per minute (by inspiration or exhalation), which are the desired value, those. the number of extrema (max or min) is equal to the respiratory rate. The normal respiratory rate is 10-12 per minute, a drop below or equal to 6 or an increase to 100-120 (in newborns) triggers an alarm.

 MP 2 sets the operating modes of generator 1, then sets the measurement modes (number of measurements in s, in min) from ECG, IPG and temperature blocks: a continuous, discrete discrete step, outputs the parameters of the measured information to the LCD display, stores the parameters of the measured information in non-volatile memory (ANZP) with reference to real time. The serial interface bus is used to set the operating modes of the device through MP 2, in addition, through this bus you can read the information recorded in the EEC on a computer, then in the hospital through this bus you can connect the device to the central monitoring system.

 The ECG measurement mode (figure 2). In this mode, the receiving electrodes PEL1 and PEL2 work. The input signal Uin with a value of approximately 1 mV has the form shown in Fig. 6, after amplification up to 10 mV on OU10 with simultaneous reduction to the axis, the abscissa has the form Uout 1. After amplification on OU12 it has the form Uout 2, modulated by an industrial frequency noise of 50 Hz, which is removed by the notch filter 16, after which it enters the MP 2 via the "f" bus, where it is read, processed and displayed on the LCD in digital form. If the heart rate decreases to 40 beats per minute and if it increases to 120 beats per minute, an alarm will be generated (values may be different, 40 and 120 - standard ones are taken). Figure 6 shows the ECG curves and their appearance according to the results of the treatments.

 To obtain a heart rate, the ECG signal in MP 2 undergoes conventional algorithmic processing according to the scheme in Fig.7.

 The proposed device can be used as an individual means of monitoring the basic physiological functions of the patient at rest and in motion (which is especially important), to transmit the measured information through the biotelemetric channel to a distance of up to 100 m. The introduction of an alarm signal improves operational qualities. Remote control (Remote Control) further enhances the operational qualities of the device, as it allows you to turn on / off, set and change measurement modes, alarm levels, etc.

Claims (10)

 1. A device for monitoring physiological functions, comprising a biotelemetry unit, a microprocessor with an LCD display, a temperature measurement unit, first and second master electrodes and an alarm unit, characterized in that a stable current generator, electrocardiogram (ECG) measurement units are inserted into it and impedance pneumograms (IPG), three control buses, five receiving electrodes located on the patient’s torso, and two information lines, while the stable current generator is connected by its outputs to the first and second master electrodes, the first, second and third receiving electrodes are connected through the first information line to the ECG and IPG measuring units, the fourth and fifth receiving electrodes are connected to the temperature measuring unit also through the first information line, the outputs of all these blocks are connected to the microprocessor information inputs via the second information line highway; the first control bus of the microprocessor is connected to the control input of the stable current generator, the second bus is connected to the alarm block, the third bus is to the biotelemetry unit, the microprocessor output is connected to the stable current generator by an on / off bus.  2. The device according to claim 1, characterized in that the device is structurally made in a wearable version in the form of a rectangular box of dielectric material, for example, of impact-resistant polystyrene, measuring 150x75x20 mm, which is attached to the patient either on a waist belt, or in a pocket, or the body with “Velcro”, and one big side of the box is not functionally involved, and on the other there is an LCD display and an antenna of radio and / or optical biotelemetry, for example, in the form of a radiating LED, from one end of the box at the ends of ≈1.5 m long terminals are fixed, for example, using a connector, two master and five receiving electrodes arranged so that the first master, first and fourth receiving electrodes are located on one rigid dielectric base, the second master, second and fifth receiving electrodes - on another rigid dielectric base, and separately, a third, receiving electrode.  3. The device according to claim 1, characterized in that the ECG unit contains: a differential operational amplifier, an integrator, a scaling operational amplifier and a notch filter, while the direct and inverse inputs of the differential operational amplifier are connected to the first and second receiving electrodes, and the output through a scaling operational amplifier and a notch filter are connected through the second information highway with the microprocessor information inputs f, and through the integrator is additionally connected to its control input m.  4. The device according to p. 1, characterized in that the IPG unit contains the first, second and third operational amplifiers, the first, second and third synchronous rectifiers, while the first, second and third receiving electrodes are connected in pairs with the inputs of three operational amplifiers included in differential mode, the outputs of which are connected via synchronous rectifiers and a second information line to the information inputs h of the microprocessor.  5. The device according to claim 1, characterized in that the temperature measuring unit comprises first and second Schmidt triggers, the fourth and fifth electrodes being connected to the inputs of the first and second Schmidt triggers, respectively, the outputs of the Schmidt triggers of the temperature measuring unit through the second information highway connected to the information microprocessor g inputs.  6. The device according to claim 1, characterized in that the fourth and fifth receiving electrodes are small-sized temperature sensors based on cut piezoelectric elements in a flat ceramic or glass case measuring 2.3 • 14 mm.  7. The device according to claim 1, characterized in that the first and second driving electrodes, the first, second and third receiving electrodes are made in the form of disks with a diameter of 3-15 mm and a thickness of 0.4-0.8 mm, made of non-oxidizing material, for example, tin, while the first master, first and fourth receiving electrodes are configured to fasten a rigid dielectric base on which they are located on the left side of the patient’s torso, the second master, second and fifth receiving electrodes are also possible on a rigid dielectric base mounting on the right side of the torso, the distance between the first (second) master and the first (second) receiving electrode on each part of the torso lies within 3-5 disc diameters, and the third receiving electrode is made with the possibility of mounting at the base of the larynx or lower, up to aperture.  8. The device according to claim 6, characterized in that either the thermistor or the pn junction of the diode or transistor are used as the receiving fourth and fifth receiving electrodes.  9. The device according to claim 1, characterized in that the first information highway is made in the form of a common flexible electrode cable, the number of signal cores of which corresponds to the number of master and receiving electrodes.  10. The device according to claim 1, characterized in that a remote control channel is inserted into it.

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