JPH02154741A - Kidney function inspecting apparatus - Google Patents

Abstract

PURPOSE:To eliminate individual errors of measured values by calculating the impedance in the body of a person to be examined, further making prescribed arithmetic processing in accordance with this impedance and the information on the body and calculating the moisture content and electrolyte concn. in the body of the person to be examined. CONSTITUTION:Electrodes 1a, 1b for voltage detection and electrodes 3a, 3b for current supply are mounted respectively to the arbitrary sections of the patient's body and the information on the body including the weight, height, age and sex at the point of the present time of the patient is inputted from the keyboard of an information input section 7. An AC current is supplied from a current generating section 4 to the electrodes 3a, 3b when the inspection is started so that the AC current flows in the patient's body and a voltage is generated between the electrodes 1a and 1b. This voltage is detected in a detecting section 2 and is written into a memory section 6 at every predetermined time. The impedance of the patient's body is calculated in a data processing section 5 from this voltage and the AC current; further, the information on the patient's body is arithmetically processed in a data processing section 5 by which the moisture content and electrolyte concn. in the patient's body are calculated. The values thereof are displayed on a display section 8.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a renal function testing device suitable for use in hemodialysis therapy.

"Prior Art" Conventionally, hemodialysis therapy has been performed on chronic renal failure patients to remove water, electrolytes, etc. from the body.

By the way, when performing hemodialysis, it is necessary to accurately grasp the extent to which the amount of water in a patient's body and the amount of electrolyte contained therein have changed. Therefore, water content is determined by measuring changes in body weight before and after dialysis, or by using measurement aids. On the other hand, the amount of electrolyte is determined by biochemically testing the patient's blood before and after dialysis.

"Problems to be Solved by the Invention" By the way, the above-described conventional method for determining the amount of water in the body and the amount of electrolyte contained therein has the following problems. Note that the terms ``■'' and ``■'' are problems that occur when determining the amount of water, and the terms ``■'', ``■,'' and 0 are problems that occur when determining the amount of electrolyte. Also, the 0 term is a problem common to both.

■Requires large-scale equipment such as scales and beds, resulting in high costs.

■Measurement auxiliary substances may have an impact on the human body.

■Blood must be collected from the patient, and blood is collected from patients with renal failure who are already severely anemic, which promotes anemia.

■It takes half a day to several days to obtain test results, and adjustments cannot be made during dialysis.

■None of the substances in the blood that are being measured (e.g., potassium, creatinine, etc.) alone can represent the entire uremic toxins that are intended to be removed except for water.
Blood components make up only a small portion of the entire body fluid, and test data does not necessarily reflect the state of the entire body, so accurate measurements cannot be made.

■Measurement is easily influenced by the skill and intuition of the user (such as a doctor).

This results in individual differences in measured values.

This invention was made in view of the above-mentioned circumstances, and aims to provide a renal function testing device that can solve each of the above-mentioned problems.

This invention utilizes the fact that the amount of water in the body and the amount of electrolyte have a close relationship with the impedance of the body.
A first pair of terminals and a second pair of terminals that are brought into contact with each other at an arbitrary distance from the body of a subject (patient); a current generating section that supplies an alternating current to the first pair of terminals; and the second terminal. A renal function testing device comprising: a detection unit that detects a voltage generated between the pairs; an information input unit that inputs physical information of the subject; , calculate the impedance in the subject's body based on the voltage and the alternating current, and further perform predetermined calculation processing based on the impedance and the physical information to calculate the water content and electrolyte concentration in the subject's body. and a display section that displays the water content and the electrolyte concentration.

"Operation" According to the above configuration, when alternating current is supplied to the first pair of terminals, the alternating current flows between these terminals through the human body of the subject, and a voltage is generated between the second pair of terminals. This voltage is detected by the detection unit and written into the storage unit at predetermined time intervals, and the impedance of the subject's body is calculated from this voltage and the alternating current. Physical information such as height, weight, gender, and age are processed to calculate the amount of water and electrolyte concentration in the subject's body. Then, the calculated water content and electrolyte concentration are displayed on the display section.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The figure is a block diagram showing the electrical configuration of an embodiment of the present invention. In this figure, la and lb are voltage detection electrodes, one voltage detection electrode la is connected to the input terminal 2a of the detection section 2, and the other voltage detection electrode 1b is connected to the input terminal 2b of the detection section 2. It is connected to the. The detection unit 2 detects the voltage generated between the voltage detection electrodes 1a and 1b,
This is converted into binary logic data (hereinafter referred to as voltage data) and output to the outside. 3a and 3b are current supply electrodes, one current supply electrode 3a is connected to the output terminal 4al of the current generation section 4, and the other current supply i-pole 3b is connected to the output terminal 4b of the current generation section 4. It is connected. The current generator 4 generates an alternating current having a constant frequency and current value (for example, 50 kHz, 800 it A). 5 is a data processing unit, which includes a CPU (central processing unit) and a RAM (not shown).
(Random Access Memory) and ROM (Read Only Memory). ROM has CPU
A control program and the output current value (800 μA) of the above-mentioned current generating section 4 are written. This data processing unit 5 has the function of controlling each part of the device and performing predetermined calculations based on various data supplied from the outside to calculate the amount of water and electrolyte concentration in the patient's body, and the function of calculating the amount of water and electrolyte concentration in the patient's body. It has the function of converting concentration into data for display. A storage section 6 stores voltage data output from the detection section 2 described above. Reference numeral 7 denotes an information input section, which includes a keyboard (not shown). The patient's physical information such as height, weight, gender, age, etc. is entered via this keyboard.

A display section 8 includes a liquid crystal display, and graphically displays water content and electrolyte concentration with respect to elapsed time based on display data supplied from the data processing section 5 described above. 9 is a battery that supplies power to each part of the device. The above-mentioned voltage supply electrodes L a, l b
, the detection section 2, the current supply electrodes 3a, 3bSS current phase-producing section 4, the data processing section 5, the storage section 6, the information input section 7, and the display section 8 constitute a renal function testing device.

Next, the operation of the renal function testing apparatus having the above-mentioned configuration will be described, taking as an example the case where it is used together with a hemodialysis apparatus (not shown).

First, a hemodialysis machine is set on a patient. Next, a power switch (not shown) of the renal function testing apparatus is turned on. Next, the voltage detection electrodes 1a, Ib and the current supply electrodes 3a, 3b are attached to any part of the patient's body. In this case, for example, the current supply electrodes 3a, 3b
Attach one of them to your head and the other to your feet. Further, one of the voltage detection electrodes 1a and 1b is attached to the ventral side of the body, and the other is attached to the dorsal side.

Next, the patient's current physical information such as weight, height, age, and gender is input from the keyboard of the information input unit 6. When the physical information is input, the data processing section 5 writes this data into the physical information storage area of its own RAM.

After completing the above settings, dialysis is started, and at the same time, a test start switch (not shown) of the renal function testing device is turned on. When the test start switch is turned on, the data processing section 5 first reads the voltage data output from the detection section 2 and writes it to the first address of the data storage area of its own RAM. Further, the same voltage data is written to the first address of the storage section 6. Next, the data processing section 5 reads out the output current value stored in its own ROM, and further reads voltage data from the data storage area of its own RAM. Then, impedance is calculated from these output current values and voltage data, and predetermined arithmetic processing is performed based on the calculated impedance and physical information to calculate the water content and electrolyte concentration in the patient's body. Here, the physical information is a parameter for correcting the water amount and electrolyte concentration obtained based on the impedance described above. For example, a taller patient will have a longer distance between the electrodes than a shorter patient even if the electrodes are attached to the same location. therefore,
The voltage drop will be greater and the impedance will be greater compared to a shorter patient. As a result, a small amount of water can be obtained. For this reason, the water content is corrected to increase as the height of the patient increases. In addition, in the case of older patients, the impedance is shown to be larger because the body tissues such as cells have aged compared to younger patients even with the same amount of water. Therefore, the moisture content is corrected to increase as the age increases. Next, the data processing section 5
converts the calculated water content and electrolyte concentration into data for display, and supplies this to the display section 8. Immediately after supplying the same data to the display section 8, the operation is then stopped for a predetermined period of time. Here, when the data is supplied to the display section 8, the water content and electrolyte concentration corresponding to the data are displayed graphically.

Next, immediately after a predetermined period of time has elapsed, the data processing section 5 again reads the voltage data supplied from the detection section 2 and writes it into the data storage area of its own RAM. Furthermore, the same voltage data is written to the second address of the storage section 6. Then,
After writing the voltage data to the storage unit 6, the data processing unit 5 calculates impedance from the voltage data and the output current value in the same manner as described above, and further performs predetermined calculation processing from the calculated impedance and physical information. Calculate the water content and electrolyte concentration. The calculated water content and electrolyte concentration are then converted into display data and supplied to the display unit 8. As a result, the water content and electrolyte concentration corresponding to the second voltage data are displayed graphically on the display section 8. Thereafter, the above-described operations are performed until the end of hemodialysis.

In this way, the impedance in the patient's body is calculated,
Based on this impedance and physical information, predetermined arithmetic processing is performed to calculate the amount of water and electrolyte concentration in the patient's body.

Furthermore, the water content and electrolyte concentration are displayed graphically over time.

In the above embodiment, the impedance of the patient's body was determined from the output current value and voltage data, and the water content and electrolyte concentration were determined by adding physical information to this impedance. Changes in the waveform of the voltage detected may also be taken into account.

Further, in the above embodiment, the voltage detection electrode Ia,
Although the mounting of Ib and the current supply electrodes 3a, 3b has ignored the fact that the detected voltage value differs depending on the position, this may be taken into consideration. For example, when attaching each electrode, a correction coefficient is determined in advance according to the position, and this is used when calculating the impedance.

Furthermore, although the above embodiments do not include changes in the patient's weight during dialysis, they may be included. In this case, by attaching a weight scale to the bed, it becomes possible to measure the weight during dialysis.

Furthermore, in the above embodiments, when a dialysis machine is attached to a patient, changes in impedance due to blood, dialysate, etc. flowing between the patient's body and the dialysis machine were not taken into consideration. good. In this case, by calculating the impedance before the start of dialysis and immediately after the start of dialysis, it becomes possible to correct the impedance error caused by the dialysis apparatus.

Further, in the above embodiment, a function may be provided to stop the device when the impedance reaches a predetermined value.

Further, in the above embodiment, the frequency and output current value of the current generating section 4 are kept constant, but they may be made variable. In this case, data indicating the frequency and output current value is supplied to the data processing section 5.

Further, in the above embodiment, a battery was used as a power source, but a commercial power source may be used instead.

In this case, it goes without saying that it is necessary to convert the commercial power supply voltage to a low DC voltage.

"Effects of the Invention" As explained above, according to the present invention, predetermined calculations are performed from the impedance of the patient's body and physical information, and the water content and electrolyte concentration of the patient's body are calculated. Compared to the above method, this method has the following effects.

■The amount of water and electrolyte concentration in a patient's body can be determined extremely quickly and accurately.

■Since no burden is placed on the patient, limitations associated with measurement are greatly reduced. Therefore, subsequent treatment after dialysis can be carried out very appropriately.

■It is harmless and safe as it does not use chemicals or other auxiliary substances for measurement.

■No need for large-scale equipment such as a weigher or bed.

■It is not influenced by the user's skill or intuition.

■Since a battery can be used as a power source, it can be made smaller.

[Brief explanation of the drawing]

The figure is a block diagram showing the electrical configuration of an embodiment of the present invention. 1 a, I b... Voltage detection electrode, 2...
...detection section, 3a, 3b...current supply electrode, 4...current generation section, 5...data processing section, 6...memory section, 7... information input section, 8... display section.

Claims (1)

[Claims] A first pair of terminals and a second pair of terminals that are brought into contact with each other at an arbitrary interval on the body of the subject, a current generating section that supplies an alternating current to the first pair of terminals, and a pair of terminals between the second pair of terminals. A renal function testing device comprising: a detection unit that detects a generated voltage; an information input unit that inputs physical information of the subject; a data processing unit that calculates impedance in the subject's body based on the alternating current, and further performs predetermined calculation processing based on the impedance and the physical information to calculate the water content and electrolyte concentration in the subject's body; and a display section that displays the water content and the electrolyte concentration.