JP2785286B2 - Renal function testing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a renal function test apparatus suitable for use in hemodialysis therapy.

[Prior Art] Conventionally, hemodialysis therapy has been performed for patients with chronic renal failure to remove water, electrolytes and the like in the body.

By the way, when hemodialysis is performed, it is necessary to accurately grasp how much the water content in the patient's body and the electrolytic mass contained therein have changed. Therefore, a method of measuring the change in body weight before and after dialysis and a method of determining the amount of water by using a measurement auxiliary substance are used. On the other hand, a method of biochemically examining the blood of a patient before and after dialysis to determine the electrolytic mass is used.

"Problems to be Solved by the Invention" By the way, the above-mentioned conventional method for determining the amount of water in the body and the electrolytic mass contained therein has the following problems. Each of the terms is a problem that occurs when calculating the amount of water, and each of the items is a problem that occurs when calculating the electrolytic mass. The term is a common problem for both.

It requires large-scale equipment such as weighing and beds, and is costly.

 The effect of the measurement auxiliary substance on the human body is considered.

Blood must be collected from the patient, which contributes to anemia because blood must be collected from patients with renal insufficiency that are only highly anemic.

It takes half a day to several days for the test results to be obtained and cannot be adjusted during dialysis.

None of the substances in the blood to be measured (eg, potassium, creatinine, etc.) alone can represent the entire uretoxin substance for the purpose of removing other than water, and blood components are part of the whole body fluid. In some cases, test data does not necessarily reflect the state of the entire body, so that accurate measurements cannot be made.

The measurement is easily influenced by the skill and intuition of the user (doctor or the like). For this reason, there are individual differences in measured values.

The present invention has been made in view of the above-described circumstances, and has as its object to provide a renal function testing apparatus that can solve the above-described problems.

"Means for Solving the Problems" The present invention utilizes the fact that the amount of water in the body and the electrolytic mass have a close relationship with the impedance of the body, and the distance between the body of the subject (patient) is arbitrary. A first terminal pair to be brought into contact with the first terminal pair, and a second terminal to be brought into contact with the subject's body inside an area where the first terminal pair is brought into contact.
A pair of terminals, a current generating unit that supplies an alternating current between the first pair of terminals, a detecting unit that detects a voltage generated between the second pair of terminals, and the gender, age, An information input unit for inputting physical information including height or weight, and the voltage is written to the storage unit at predetermined time intervals, and the impedance in the body of the subject is calculated based on the voltage and the AC current. Further, based on the impedance, a data processing unit that performs a calculation process including a correction process based on the physical information stored in the storage unit and calculates a water content and an electrolyte concentration in the body of the subject, and the water content and A display unit for displaying the electrolyte concentration.

[Operation] According to the above configuration, when an alternating current is supplied to the first pair of terminals, an alternating current flows between these terminals via 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 to the storage unit at predetermined time intervals, and the impedance of the subject's body is calculated from the voltage and the alternating current. Physical information such as height, weight, gender, age and the like are arithmetically processed to calculate the water content and electrolyte concentration in the subject's body. Then, the calculated water content and electrolyte concentration are displayed on the display unit.

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

FIG. 1 is a block diagram showing an electrical configuration of an embodiment of the present invention. In this figure, reference numerals 1a and 1b denote voltage detection electrodes, respectively. One voltage detection electrode 1a is connected to the input terminal 2a of the detection unit 2, and the other voltage detection electrode 1b is connected to the input terminal 2b of the detection unit 2. It is connected to the. The detection unit 2 detects a voltage generated between the voltage detection electrodes 1a and 1b, converts the voltage into binary logic data (hereinafter, referred to as voltage data), and outputs the data to the outside. 3a and 3b are current supply electrodes, respectively.
One current supply electrode 3a is connected to the output terminal 4a of the current generator 4, and the other current supply electrode 3b is connected to the output terminal 4b of the current generator 4. The current generator 4 generates an alternating current having a constant frequency and a constant current value (for example, 50 kHz, 800 μa). Reference numeral 5 denotes a data processing unit, which is a CPU (central porsing unit, RAM (random access memory) and ROM (read-on memory), not shown)
Is configured. The ROM includes a program for controlling the CPU and the travel current value (800 μm) of the current generator 4 described above.
A) is written. The data processing unit 5 controls each unit of the apparatus and performs a predetermined calculation based on various data supplied from the outside to calculate a water content and an electrolyte concentration in the patient's body. It has a function of converting the density into display data. A storage unit 6 stores the voltage data output from the detection unit 2 described above. Reference numeral 7 denotes an information input unit, which includes a keyboard (not shown). Physical information such as height, weight, gender, age, etc. of the patient is input via the keyboard. Reference numeral 8 denotes a display unit, which includes a liquid crystal display, and displays a graph of the water content and the electrolyte concentration with respect to the elapsed time based on the display data supplied from the data processing unit 5 described above. 9
Denotes a battery for supplying power to each unit of the apparatus. The above-described voltage supply electrodes 1a and 1b, the detection unit 2, and the current supply electrodes 3a and 3
b, the current generating unit 4, the data processing unit 5, the storage unit 6, the information input unit 7, and the display unit 8 constitute a renal function testing device.

Next, the operation of the renal function test apparatus having the above-described configuration will be described with reference to an example in which the apparatus 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 liver function test apparatus is turned on. Next, each of the voltage detection electrodes 1a and 1b and the current supply electrodes 3a and 3b is attached to an arbitrary part of the patient's body. In this case, for example, one of the current supply electrodes 3a and 3b is attached to the head, and the other is attached to the end of the morning. One of the voltage detection electrodes 1a and 1b is attached to the abdomen of the body, and the other is attached to the back. Next, the patient's current weight, height, age, and gender physical information are input from the keyboard of the information input unit 6. When the physical information is input, the data processing unit 5 writes the data into the height information storage area of the RAM of the earthquake. After the above setting is completed, dialysis is started, and at the same time, a test start switch (not shown) of the renal function test device is turned on. When the inspection start switch is turned on, the data processing unit 5 first reads the voltage data output from the detection unit 2 and writes the voltage data into the head address of the data storage area of its own RAM. Further, the same voltage data is written to the head address of the storage unit 6. Next, the data processing unit 5
Reads the output current value stored in ROM,
Read voltage data from AM data storage area. Then, the impedance is calculated from the output current value and the voltage data, and a predetermined calculation process is performed based on the calculated impedance and the body information to calculate the water content and the electrolyte concentration in the patient's body. Here, the physical information is a parameter for correcting the water content and the electrolyte concentration obtained based on the impedance described above. For example, a tall patient will have a longer distance between electrodes even if electrodes are attached to the same site than a short patient. Therefore, the voltage drop becomes large and the impedance becomes large as compared with a patient of short height. As a result, a small amount of water can be obtained. To this end, the correction is made in such a manner that the water content increases as the height of the patient increases. In addition, in the case of an older patient, since the body tissue such as cells is aged even with the same water content as compared to a young patient, the impedance is greatly shown. Therefore, the correction is made so that the water content increases as the age increases. Next, the data processing unit 5 converts the calculated water content and electrolyte concentration into display data and supplies them to the display unit 8.
Next, the operation is stopped for a predetermined time immediately after the same data is supplied to the display unit 8. Here, when the data is supplied to the display unit 8, the water content and the electrolyte concentration corresponding to the data are displayed in a graph.

Next, immediately after a lapse of a predetermined time, the data processing unit 5 reads the voltage data supplied from the detection unit 2 again and writes the voltage data in the data storage area of its own RAM. Further, the same voltage data is written to the second address of the storage unit 6. Then
After writing the voltage data into the storage unit 6, the data processing unit 5 calculates an impedance from the voltage data and the output current value in the same manner as the above-described operation, and further performs a predetermined calculation process from the calculated impedance and the body information. Then, the water content and the electrolyte concentration are calculated. Then, the calculated water content and electrolyte concentration are converted into data for display, and the display unit 8
Supply to As a result, the water content and the electrolyte concentration corresponding to the second voltage data are graphically displayed on the display unit 8. Hereinafter, the above-described operation is performed until the end of hemodialysis.

As described above, the impedance in the patient's body is calculated, and a predetermined calculation process is performed from the impedance and the body information to calculate the water content and the electrolyte concentration in the patient's body. Further, a graph of the amount of water and the concentration of electrolyte according to the passage of time is displayed.

In the above embodiment, the impedance of the patient's body was determined from the output current value and the voltage data, and the water content and the electrolyte concentration were determined by adding the body information to the impedance. The information on the voltage waveform calculated in step 2 may be added.

Further, in the above embodiment, the voltage detection electrodes 1a, 1b
Although the point that the value of the detected voltage differs depending on the mounting position of each of the current supply electrodes 3a and 3b has been neglected, it may be narrow. For example, a correction coefficient corresponding to the mounting position of each electrode is obtained, and is used for calculating the impedance.

Further, in the above embodiment, the change in the weight of the patient during dialysis is not introduced, but this may be included. In this case, the weight can be measured during dialysis by attaching a weight scale to the bed.

Further, in the above embodiment, when the dialysis device was attached to the patient, changes in impedance due to blood, dialysate, etc. flowing between the patient's body and the dialysis device were not taken into account. You may consider it. 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 due to the dialysis device.

Further, in the above-described embodiment, a function of stopping the device when the impedance becomes a predetermined value may be provided.

Further, in the above embodiment, the frequency and the output current value of the current generator 4 are fixed, but may be variable. In this case, data indicating the frequency and the output current value is supplied to the data processing unit 5.

In the above embodiment, a battery is used as a power supply, but a commercial power supply may be used instead.
In this case, it is needless to say that the commercial power supply voltage needs to be converted to a low DC voltage.

[Effects of the Invention] As described above, according to the present invention, a predetermined calculation is performed from the impedance and the body information of the patient's body, and the water content and the electrolyte concentration of the patient's body are determined.
The following effects are obtained as compared with the conventional method.

The water content and electrolyte concentration of the patient's body can be determined very quickly and accurately.

Since there is no burden on the patient, the constraints associated with the measurement are greatly reduced. Therefore, the subsequent treatment after dialysis can be performed very appropriately.

Harmless and safe because no chemicals or other auxiliary substances for measurement are used.

No extensive equipment such as weighing and beds is required.

 It does not depend on the skill or intuition of the user.

Since a battery can be used as a power source, the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical configuration of an embodiment of the present invention. 1a, 1b: voltage detection electrode, 2: detection section, 3a, 3b: current supply electrode, 4: current generation section, 5: data processing section, 6: storage section, 7: information Input unit, 8 ... Display unit.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-802517 (JP, A) JP-A-52-149889 (JP, A) JP-A 50-125597 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) A61B 5/05 A61M 1/14

Claims (1)

(57) [Claims] 1. A first terminal pair for contacting a subject at an arbitrary distance from a subject's body, and a second terminal pair for contacting the subject's body inside an area where the first terminal pair contacts. A current generator for supplying an alternating current between the first pair of terminals, a detector for detecting a voltage generated between the second pair of terminals, and the sex, age, height or weight of the subject. An information input unit for inputting physical information including, and while writing the voltage to the storage unit at predetermined intervals, calculating an impedance in the body of the subject based on the voltage and the alternating current, Based on the impedance, a data processing unit that performs an arithmetic process including a correction process based on the physical information stored in the storage unit and calculates a water content and an electrolyte concentration in the subject's body, and the water content and the Renal function testing device, characterized by comprising a display unit for displaying the solution electrolyte concentration.