JP4560751B2 - Bioactivity monitor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bioactivity monitor that measures the organ or tissue activity of a living body.
[0002]
[Prior art]
The signals that can be electrically induced and detected from the body surface of a living body include biological organ electrical signals such as an electroencephalogram, an electrocardiogram, an electromyogram, and an electrogastrogram, and these signals include the following components.
(1) Living organ electrical signal, (2) Thermal noise due to resistance component of electrode system, (3) Internal noise of detection amplifier, (4) Sliding noise of electrode due to movement of living body or vibration from outside, (5 ) Noise due to polarization voltage of electrode part, (6) Electrically induced noise from outside, (7) 1 / f noise due to current fluctuation around measurement site, (8) Noise from epidermis (tissue) cells
[0003]
Among these, for the noises (2) to (7), a method for improving the noise to the extent that does not hinder the measurement of (1) has already been established, but an appropriate method has been established for (8). Not.
[0004]
[Problems to be solved by the invention]
Conventionally, it is necessary to measure brain waves to determine brain death. However, when an electroencephalogram is to be measured, noise from epidermal cells is an obstacle, and accurate brain death determination is difficult. Because when the brain wave signal is taken out by the detector, the skin is still active in the case of brain death, and even if the noise of (2) to (7) is removed, the noise of (8) is included. is there.
[0005]
The present invention has been made in view of such points, and its purpose is to accurately determine brain death by measuring noise from epidermal cells, and further by determining the activity of a living body. is there.
[0006]
[Means for Solving the Problems]
Human skin is composed of three layers: epidermis, dermis, and subcutaneous tissue. Among these, it is the epidermis that is involved in the noise included in the biological signal derived from the electrode attached to the skin. The main constituents of the epidermis are epidermal cells. Epidermal cells occur at the position in contact with the dermis. The undifferentiated cells that develop (basal cells) proliferate, move from the spinous cells to the granule cells, move to the surface layer, become keratinocytes, and peel off from the skin surface after a certain time. follow.
[0007]
In this process, epidermal cells are elongated in the direction along the surface layer before they become corneocytes, and then collapse and the cell fluid overflows from the cell membrane. Changes and noise is generated. This noise is greater as the tissue is more active. Therefore, the degree of tissue activity can be determined by measuring the noise generated from the epidermal cells.
[0008]
The present invention is intended to actively measure the noise caused by the epidermal cells, which has been conventionally targeted for removal, to obtain tissue activity based on this noise, and to use it to determine brain death. is there.
[0009]
FIG. 15 shows the relationship between the resistance value R between two electrodes and the potential difference between the electrodes converted into a noise level by an amplifier in which two electrodes are mounted on human skin and the internal noise is as small as possible. It is a thing. The resistance value R is obtained by passing a constant current of a certain frequency and measuring the voltage between the electrodes. The measurement results are plotted with white circles.
[0010]
In this example, the amplifier is a differential amplifier, and the output is passed through a band-pass filter. After being squared, the output is smoothed, and an effective value νn per unit frequency is calculated from the average value. There were 10 subjects, and the test was performed using a DEG electrode for electroencephalogram coated with paste. The resistance value R between the electrodes is expressed as a pure resistance by applying a 10 Hz sine wave between the electrodes, obtaining an apparent resistance and a phase advance amount, and regarding the electrode impedance as a resistance-capacitance parallel circuit. is there. The attachment site is the scalp.
[0011]
The black diamonds plotted in FIG. 15 connect both ends of the fixed resistor of the electronic component to the same device as described above, and the resistance value of the fixed resistor measured by the device and the noise level generated from the fixed resistor. And the amplifier internal noise shows the power being summed. As shown in this figure, even with the same resistance value, the skin resistance (white circle mark) has a higher noise level. The noise of the skin resistance approaches the value of the fixed resistor as the resistance value R is small, but does not reach a match. The more active a living tissue is, the greater this noise is. Therefore, if the noise level resulting from the skin resistance is measured, the bioactivity can be measured.
[0012]
FIG. 16 shows the results of measurement of noise from brain waves and scalp, as well as noise from ear lobes, fixed resistance, paste, water-kneaded flour, and chicken. According to this measurement result, it can be seen that even ionic resistance like wheat flour kneaded with water shows almost the same value as fixed resistance.
[0013]
Accordingly, the invention of claim 1 detects a potential difference between the pair of electrodes, a resistance measuring means for obtaining a resistance between the pair of electrodes, and a potential difference between the pair of electrodes. The noise measurement means for converting the noise level into the noise level, the resistance value measured by the resistance measurement means, and the measurement data storage means for storing the noise levels measured by the noise measurement means in correspondence with each other.
[0014]
According to such a configuration, the resistance value of the skin resistance at the electrode mounting site and the noise generated from the skin resistance are measured.
[0015]
The invention according to claim 2 is characterized by comprising display means for displaying data based on the contents stored in the measurement data storage means. Thereby, the operator can see the measurement result.
[0016]
The invention according to claim 3 detects a potential difference between the pair of electrodes, a pair of electrodes to be attached to the epidermis of a living body, resistance measuring means for obtaining a resistance between the pair of electrodes, and this is detected as noise. Noise measurement means for converting into a level; resistance value measured by the resistance measurement means; measurement data storage means for storing the noise measured by the noise measurement means in association with each other; The reference data storage means for storing the reference data indicating the relationship between the resistance value of the skin resistance and the noise level resulting from the skin resistance, the content stored by the measurement data storage means, and the reference data storage means And a display means for displaying data based on the contents. According to this, the measured noise level can be viewed with reference to the standard data.
[0017]
The invention according to claim 4 detects a potential difference between the pair of electrodes, a pair of electrodes to be attached to the epidermis of a living body, resistance measuring means for obtaining a resistance between the pair of electrodes, and this is detected as noise. Noise measurement means for converting to level, resistance value measured by the resistance measurement means, measurement data storage means for storing the noise level measured by the noise measurement means in association with each other, and a predetermined area on the skin surface of the living body Reference data storage means for storing reference data indicating the relationship between the resistance value of the perimeter skin resistance and the noise generated from the skin resistance, the noise level measured by the noise measurement means, and the reference stored by the reference data storage means A configuration is provided that includes notifying means that performs predetermined notification with reference to the data. According to this, when the measurement noise level is present with respect to the reference data, this is notified.
[0018]
The invention according to claim 5 is characterized in that the notification means is a means for notifying that it is necessary to wipe the mounting portion of the pair of electrodes. According to this, the operator can know the increase in the skin resistance of the wearing part and know that it is necessary to wipe the wearing part.
[0019]
The invention of claim 6 is characterized in that the notifying means is means for notifying that it is at a brain death level. Thereby, the operator can know that the subject is in a brain dead state.
[0020]
According to a seventh aspect of the invention, the notification means is a brain death level when a noise level at a certain resistance value measured by the noise measurement means is within a predetermined range with respect to the noise level of the reference data at the resistance value. This is notified, and when it is outside the predetermined range, it is notified that it is necessary to wipe the mounting part of the pair of electrodes. According to this, the operator can know that the subject is in a brain-dead state after sufficiently wiping the electrode mounting site.
[0021]
The invention of claim 8 is characterized in that the notifying means is means for notifying the activity of the epidermis. According to this, it is possible to know the skin condition of the subject.
[0022]
The invention according to claim 9 is characterized in that the reference data is data of a healthy person. According to this, notification and display of measurement data are performed on the basis of a healthy person.
[0023]
The invention of claim 10 includes at least three electrodes to be attached to the skin of a living body, resistance measuring means for obtaining a skin resistance value in the thickness direction of each part to which each of the electrodes is attached, and each of the skin resistances. A resistance value change detecting means for detecting a change in value is provided. According to this, the potential at each part can be accurately derived.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a bioactivity monitor according to the first embodiment of the present invention. This device is a device for obtaining epidermis activity data of the skin of a normal healthy person, that is, reference data, and comprises an electrode unit 1, a biological signal detection unit 2, and a data processing / control unit 3. Yes.
[0025]
As shown in FIG. 2, the electrode unit 1 includes a ring-shaped electrode 1a, a disk-shaped electrode 1b disposed in the electrode 1a, a sheet-shaped holding unit 1c that holds these electrodes, and respective potentials. It consists of lead wires 1d and 1e for leading out. The area of the mounting surface of the electrode 1a and the electrode 1b is the same.
[0026]
As shown in FIG. 1, the biological signal detection unit 2 includes a transmitter 4, a resistance measurement circuit 5 that generates a constant current having a frequency indicated by the transmitter 4, and a current from the resistance measurement circuit 5 to the electrode unit 1. It comprises a switch 6 for switching whether to flow, a preamplifier 8, and an input short circuit 7 for switching whether to input a signal from the switch 6 to this preamplifier 8 or to short-circuit its input terminal. . The frequency of the transmitter 4 is 10 Hz.
[0027]
The data processing / control unit 3 performs an operation based on an A / D conversion unit 9 that converts a signal from the biological signal detection unit 2 into a digital signal, a storage unit 10 that stores data, and a program stored in the storage unit 10. The calculation unit 11 to be performed, the display unit 12 for displaying the calculation result of the calculation unit 11, the operation unit 13 for inputting instructions and necessary data to the apparatus, and the resistance value is temperature-corrected and converted into the thermal noise level. A data table 14 having necessary tables and a control unit 15 for controlling each unit are provided. The data processing / control unit 3 is configured by a digital computer. FIG. 3 shows a flowchart of processing performed by the data processing / control unit 3.
[0028]
Next, the operation of the apparatus configured as described above will be described with reference to FIG. Here, the skin resistance and noise level of the subject's scalp are measured.
[0029]
First, the operator wears the electrode unit 1 on the subject's scalp. In this state, turn on the device. At this time, the control unit 15 short-circuits the input short circuit 7, measures the output voltage due to the internal resistance of the preamplifier 8, performs the same processing as steps 121 to 123 described later, converts it to a noise level, and stores this. Store in the unit 10 (step 101).
[0030]
Next, the control unit 15 switches the switch 6 and the input short circuit 7 to the resistance measurement mode, and operates the transmitter 4. As a result, the resistance measurement circuit 5 passes a constant current of 10 Hz between the electrodes 1 a and 1 b of the electrode unit 1. The voltage between the electrodes 1a and 1b passes through the switch 6 and the input short circuit 7 to the preamplifier 8, where it is amplified and converted into a digital signal by the A / D converter 9, and reaches the arithmetic unit 11. And the calculating part 11 calculates | requires the skin resistance value between this electrode based on the voltage between this electrode, and converts and calculates | requires thermal noise from this resistance value (step 102).
[0031]
FIG. 4 shows the details of the processing in step 102 described above. That is, the calculation unit 11 performs a band-pass filter process to extract a 10 Hz voltage from the given voltage signal (step 111), and uses the signal from the transmitter 4 to perform synchronous detection using the extracted voltage. A resistance value is calculated from the output (step 112), and the obtained resistance value is temperature-corrected by referring to temperature data obtained from a temperature sensor (not shown) and the contents of the data table 14, and further to a thermal noise level. They are converted (step 113), and the resistance values and the thermal noise levels are associated with each other and stored in the storage unit 10 (step 114).
[0032]
Next, the control unit 15 turns off the transmitter 4 and the resistance measurement circuit 5, and switches the switch 6 and the input short circuit 7 to the noise measurement mode. As a result, the voltage between the electrodes 1a and 1b is detected, reaches the preamplifier 8 through the switch 6 and the input short circuit 7, and is amplified and converted into a digital signal by the A / D conversion unit 9, and the calculation unit 11 It reaches. The computing unit 11 measures the noise level between the electrodes based on the voltage between the electrodes (step 103).
[0033]
FIG. 5 shows the details of the processing in step 103 described above. That is, the calculation unit 11 performs a band pass filter process to extract a voltage in a predetermined band (step 121), converts the extracted voltage signal into an effective value per unit frequency (step 122), and further averages (step 122). 123) and converted into a noise level. From the noise level measured in this way, the noise level of only the preamplifier 8 obtained in the step 101 is calculated as the power (V ² ) Subtract by calculation. That is, where
V = (Vx ² -Vs ² ) ^1/2 , Vx: measured value, Vs: short circuit value
Calculate The result is stored in the storage unit 10 in association with the resistance value obtained in step 102 (step 124). Thus, the noise level of only the preamplifier 8 is subtracted because the noise of the amplifier may not be negligible as shown in FIG. 16 (particularly in the region of 100 [kΩ] or less).
[0034]
Next, the computing unit 11 takes the ratio between the thermal noise level obtained in step 102 and the noise level measured in step 103 and associates this with the resistance value obtained in step 102 in the storage unit 10. Store (step 104).
[0035]
Next, the control unit 15 waits for an instruction to start the next resistance measurement or an instruction to end the measurement (steps 105 and 106). Here, the operator removes the electrode part 1 from the subject, rubs the attachment part with alcohol cotton or the like to change the skin resistance value R of the attachment part, attaches the electrode part 1 again to the electrode attachment part, and the operation part 13 When the measurement start instruction is issued by the control unit 15, the control unit 15 and the calculation unit 11 perform the processing of steps 102 to 104 again. Thereafter, the same processing is performed, and when an end input is made in step 106, the reference data measurement is ended.
[0036]
FIG. 6 shows the measurement result in the same logarithmic graph as in FIG. However, in this case, unlike FIG. 15, the ratio between the thermal noise level and the actual measured value (the length in the vertical axis direction on the graph) is displayed at the same resistance value. Such a measurement is performed for many healthy subjects, and the average is approximated by a straight line as shown in FIG. This straight line data is used as reference data.
[0037]
In the present embodiment, since the electrode unit 1 has a configuration as shown in FIG. 2, it is possible to take out noise due to skin resistance while avoiding an electroencephalogram signal.
[0038]
Next, a bioactivity monitor according to the second embodiment will be described. The overall configuration of this apparatus is shown in FIG. As shown in this figure, this device includes an electrode unit 100, a biological signal detection unit 2 similar to that of the first embodiment, an electroencephalogram measurement device 20 that measures an electroencephalogram, and a data processing / control device 30. It is configured.
[0039]
The electrode unit 100 includes a normal electroencephalogram measurement electrode unit 100A and a pair of brain death determination electrode units 100B. The electroencephalogram measurement electrode unit 100A has eleven electrodes a, b,..., Nine on the scalp and one on each of the left and right earlobe. Since the electroencephalogram measurement electrode unit 100B has the same configuration as that shown in FIG. 2, the same reference numerals are given to the same elements, and descriptions thereof are omitted. For each electrode, an electrode having the same mounting area as the electrode used for obtaining the reference data is used. Moreover, since the biological signal detection part 2 is the same structure as 1st Embodiment, the same number is attached | subjected to the same element and those description is abbreviate | omitted. However, since the number of electrodes is different from that of the first embodiment, the structure of the switch 6 of this embodiment corresponds to those electrodes.
[0040]
The data processing / control unit 30 performs an operation based on an A / D conversion unit 27 that converts a signal from the biological signal detection unit 2 into a digital signal, a storage unit 26 that stores data, and a program stored in the storage unit 26. A calculation unit 21 to perform, a display unit 22 for displaying the calculation result of the calculation unit 21, an operation unit 23 for inputting instructions to the apparatus and necessary data, and a resistance value for temperature correction to convert it to a thermal noise level A data table 24 having necessary tables and a control unit 25 for controlling the respective units are provided. The data processing / control unit 30 is configured by a digital computer. FIG. 8 shows a flowchart of processing performed by the data processing / control unit 30.
[0041]
This apparatus has a function of operating in two modes, a mode for measuring a normal brain wave and a mode for determining a brain death level. Then, in the electroencephalogram measurement mode, the epidermal resistance of the part where each electrode is mounted is continuously measured, and the change in the epidermal resistance is monitored. The switching between the two modes is performed by the operator operating the operation unit 23.
[0042]
Next, an outline of the operation of the apparatus configured as described above will be described with reference to FIG. First, when the power is turned on and the operation is started, the control unit 25 short-circuits the input short circuit 7 and measures the output voltage due to the internal resistance of the preamplifier 8. The level is converted and stored in the storage unit 26 (step 201).
[0043]
Next, the control unit 25 waits for an instruction to measure an electroencephalogram from the operation unit 23 (step 202) or an instruction to determine a brain death level (step 203). If there is an instruction to measure an electroencephalogram, the control unit 25 enters the electroencephalogram measurement mode. The process is performed (step 204), and if there is an instruction for determining the brain death level, the process of determining the brain death level is performed (step 205), and it is determined whether there is an instruction to end all measurements (step 206). If so, the process returns to step 202, and if there is an instruction, all measurements are terminated. Usually, the operator first measures an electroencephalogram, and then determines the brain death level when the electroencephalogram decays. Hereinafter, the operation in each mode will be described in detail.
First, the operation in the electroencephalogram measurement mode will be described. Since the normal electroencephalogram measurement performed by the electroencephalogram measurement apparatus 20 is the same as the conventional one, the description thereof will be omitted. In this electroencephalogram measurement mode, each electrode is attached. A process for monitoring a change in the skin resistance (hereinafter referred to as electrode resistance) of a portion that is present will be described with reference to FIG.
[0044]
First, the control unit 25 measures the electrode resistance of each of the electrodes a, b, c,... Of the electrode unit 100A (step 301). This measurement is as follows. First, the control unit 25 controls the switch 6 to select any two electrodes a and b from the electrode unit 100A, connect them to the resistance measurement circuit 5, and short-circuit the input short circuit 7. Is released and the transmitter 4 is operated. As a result, as shown in FIG. 10 (a), a constant current i flows between the two selected electrodes a and b, and the voltage Vab between these electrodes a and b is supplied from the switch 6 and the input short circuit 7. Then, the preamplifier 8 and the A / D conversion unit 27 are passed to the calculation unit 21. The calculation unit 21 converts the voltage signal Vab into a resistance value (Vab / i = Rab) and stores it in the storage unit 26. The resistance value Rab obtained here is the sum of the electrode resistances Ra and Rb, that is, Ra + Rb.
[0045]
Next, the control unit 25 controls the switch 6 to select an electrode c different from the two electrodes a and b selected earlier and one of the two electrodes a and b selected earlier (for example, electrodes b), the electrodes b and c and the resistance measuring circuit 5 are connected, and the transmitter 4 is operated. Thereafter, the resistance value between the two electrodes b and c is obtained in the same manner as the case between the electrodes a and b, and this is stored in the storage unit 26. The resistance value Rbc obtained here is the sum of the electrode resistances Rb and Rc, that is, Rb + Rc (see FIG. 10B).
[0046]
Next, the control unit 15 controls the switch 6 to select two electrodes, for example, electrodes a and c, which are different from the two electrodes previously combined, and measure these electrodes a and c and resistance. Connect to circuit 5 and activate transmitter 4. Thereafter, the resistance value between the two electrodes a and c is obtained in the same manner as the case between the electrodes a and b, and this is stored in the storage unit 10. The resistance value Rac obtained here is the sum of the electrode resistances Ra and Rc, that is, Ra + Rc (see FIG. 10C).
[0047]
Next, the calculation unit 11 obtains Ra, Rb, and Rc from the following three relationships (Rab, Rbc, and Rac have been measured).
Rab = Ra + Rb
Rbc = Rb + Rc
Rac = Ra + Rc
[0048]
Next, when calculating the electrode resistances of the three electrodes a, b, and c, the computing unit 21 determines the other electrode resistances as follows. As shown in FIG. 10D, an electrode d to be measured and an electrode having a known resistance value, for example, an electrode c, are selected, a constant current i is passed between them, and a voltage Vcd between the electrodes c and d is selected. Is detected. At this time, since there is a relationship of Vcd / i = Rc + Rd and Rc is known, the electrode resistance Rd of the electrode d can be obtained. Similarly, the electrode resistances of all the electrodes are obtained. The storage unit 10 stores these data. In the subsequent processing, each electrode resistance measured in step 301 is used as a reference.
[0049]
Next, the control unit 15 and the calculation unit 11 determine whether or not a predetermined time has elapsed from the resistance measurement process in step 301 (step 302). If the predetermined time has elapsed, each electrode is again processed in the same manner as described above. Resistance is measured (step 303). Next, the calculation unit 11 takes the difference between the value measured first and the value measured this time for each electrode resistance, and determines whether the difference is larger than a predetermined threshold, thereby making the electrode resistance abnormal. It is determined whether there is an increasing electrode and which electrode it is (step 304), and if there is such an electrode, this is indicated to the display unit 22, and if there is no such electrode, Return to step 302. In response to the instruction from the calculation unit 21, the display unit 22 displays a symbol for identifying an electrode whose electrode resistance is abnormally increased, for example, a number and an abnormality (step 305).
[0050]
By this display, the operator removes the corresponding electrode, wipes the measurement site, attaches the electrode to the site again, operates the operation unit 23, and inputs an instruction to start electrode resistance measurement. At this time, the control unit 25 waits for whether or not there is a start instruction (step 306) and whether or not there is a measurement end instruction (step 307). Similar processing is performed, and if there is an instruction to end the measurement, the main measurement is ended.
[0051]
According to the processing in this electroencephalogram measurement mode, all electrode resistances of the electrode unit 100A are measured every predetermined time, and abnormalities in those changes are detected and displayed. Therefore, at the time of electroencephalogram measurement, if any electrode resistance increases due to, for example, fat of the epidermis, it is displayed which electrode is the electrode. Therefore, the operator can easily identify the electrode whose electrode resistance has become abnormal, and can perform brain wave measurement quickly and accurately by performing a process such as wiping the part where the electrode is mounted.
[0052]
Next, the operation in the brain death determination mode in step 205 shown in FIG. 8 will be described with reference to the flowchart shown in FIG. In this mode, brain death determination is performed using the reference data obtained in the first embodiment. This reference data is stored in the storage unit 26 in advance.
[0053]
First, the control unit 25 measures the resistance between the electrodes 1a and 1b of the electrode unit 100B and converts the resistance into thermal noise (step 401). The measurement of the resistance between the electrodes 1a and 1b and the conversion of thermal noise have been described in the first embodiment, and will not be repeated.
[0054]
Next, the control part 25 and the calculating part 21 perform a noise measurement process from the potential difference between the electrodes 1a and 1b (step 402). This process is as follows. First, the control unit 25 turns off the transmitter 4 and the resistance measurement circuit 5 and switches the switch 6 to derive the voltage between the electrodes 1a and 1b.
[0055]
The voltage between the electrodes 1a and 1b passes through the switch 6 and the input short circuit 7 and reaches the preamplifier 8, where it is amplified and converted into a digital signal by the A / D converter 27 and reaches the arithmetic unit 21.
[0056]
Then, the computing unit 21 obtains an average effective value (noise level) of the voltage, and uses the noise level obtained by only the preamplifier 8 obtained in step 201 from the noise level as power (V ² ) Subtract by calculation. Then, a ratio with the thermal noise obtained in step 401 is obtained from the resulting noise level, and this is displayed on the screen of the display unit 22 (this ratio is indicated by the length in the vertical direction in the logarithmic graph) and the storage unit 26. (Step 403).
[0057]
The computing unit 21 compares the ratio obtained in step 403 with the reference data stored in the storage unit 26, and determines whether the ratio at the same resistance value is more than a predetermined distance from the reference data (step). 404) If the user is away, the display unit 22 is instructed to wipe the mounting portion of the electrode unit 1 (step 405).
[0058]
Next, the control unit 25 waits for a next noise measurement instruction or a measurement end instruction (steps 406 and 407). Here, the operator removes the electrode part 100B from the test subject, changes the resistance value of the electrode resistance by rubbing the electrode attachment part with alcohol cotton, etc., attaches the electrode to the electrode attachment part again, and measures with the operation part 23 When the start instruction is given, the control unit 25 and the calculation unit 21 return to the process of step 401.
[0059]
On the other hand, when it is determined in step 404 that the ratio is not more than a predetermined distance (closer) from the reference data, the calculation unit 21 determines that the level is brain death and displays that fact on the display unit 23 ( Step 408).
[0060]
In the above processing, as shown in FIG. 12, the locus of the noise level measured each time the mounting site is wiped may be displayed on the screen of the display unit 23. In general, as a brain death state is approached, an electroencephalogram signal (biological organ signal) among signals obtained from the potential difference between the electrodes 1a and 1b becomes weaker, and a noise component converted from the electroencephalogram signal decreases. However, in the case of brain death, the epidermis is in an active state. For this reason, the measured noise level becomes close to the noise only from the skin resistance (reference data). Here, if the electrode mounting site is well wiped and the skin resistance is lowered for measurement, the presence or absence of a biological organ signal can be determined more accurately.
Therefore, if the display as shown in FIG. 12 is performed, the operator can accurately determine the brain death of the subject.
[0061]
Next, a bioactivity monitor according to the third embodiment will be described. This device is a device for measuring skin activity. As shown in FIG. 13, the configuration of the apparatus includes an electrode unit 101, a biological signal detection unit 2 similar to that of the first embodiment, and a data processing / control device 40.
[0062]
The electrode unit 101 includes a pair of electrode units 101a and 101b. For each electrode, an electrode having the same mounting area as the electrode used for obtaining the reference data is used. Moreover, since the biological signal detection part 2 is the same structure as 1st Embodiment, the same number is attached | subjected to the same element and those description is abbreviate | omitted.
[0063]
The data processing / control unit 40 performs an operation based on an A / D conversion unit 47 that converts a signal from the biological signal detection unit 2 into a digital signal, a storage unit 46 that stores data, and a program stored in the storage unit 46. A calculation unit 41 to perform, a display unit 42 to display a calculation result of the calculation unit 41, an operation unit 43 for inputting instructions to the apparatus and necessary data, and a resistance value to be temperature-corrected and converted into a thermal noise level A data table 44 having necessary tables and a control unit 45 for controlling the respective units are provided. The data processing / control unit 40 is configured by a digital computer. FIG. 14 shows a flowchart of processing performed by the data processing / control unit 40. The storage unit 46 stores reference data, and further stores a program as shown in FIG. The two electrodes 1a and 1b used here are electrodes having the same mounting area as the electrodes used for obtaining the reference data.
[0064]
The operation of this apparatus will be described with reference to FIG. First, the operator turns on the power of the apparatus. At this time, the control unit 45 short-circuits the input short circuit 7, measures the output signal due to the internal resistance of the preamplifier 8, converts it to the noise level in the same manner as in Steps 121 to 123 described above, and stores this in the storage unit 46. (Step 501).
[0065]
Next, the operator attaches the electrodes 101a and 101b to the skin of the subject's arm, face, etc., and operates the operation unit 43 to instruct the start of resistance measurement. Thereby, the control part 45 switches the switch 6 and the input short circuit 7 to resistance measurement mode, and operates the transmitter 4. FIG. Here, the resistance measurement circuit 5 passes a constant current of 10 Hz between the electrodes 101 a and 101 b of the electrode portion 101. The voltage between the electrodes 101a and 101b reaches the preamplifier 8 via the switch 6 and the input short circuit 7, and is amplified here, converted into a digital signal by the A / D converter 9, and reaches the arithmetic unit 41. Then, the calculation unit 41 converts the voltage into a resistance value, converts the obtained resistance value into a thermal noise level, and stores the resistance value and the thermal noise in correspondence in the storage unit 10 (step 502).
[0066]
Next, the control unit 45 turns off the transmitter 4 and the resistance measurement circuit 5, and switches the switch 6 and the input short circuit 7 to the noise measurement mode. As a result, the voltage between the electrodes 101a and 101b reaches the preamplifier 8 via the switch 6 and the input short circuit 7, where it is amplified and converted into a digital signal by the A / D converter 9 and reaches the arithmetic unit 41. Then, the calculation unit 41 obtains an average effective value (noise) of the voltage, and calculates the noise level by only the preamplifier 8 obtained in step 501 from this noise level as power (V ² ) Subtract by calculation. Then, a ratio with the thermal noise obtained in step 502 is obtained from the resulting noise level, and this is displayed on the screen of the display unit 42 (this ratio is indicated by the length in the vertical direction in the logarithmic graph) and the storage unit 46. (Step 503).
[0067]
Next, the computing unit 41 takes the ratio between the thermal noise level obtained in step 502 and the noise level obtained in step 503, compares this with reference data for the resistance value obtained in step 502, and determines the skin activity. This is determined and displayed (step 504). For example, if the ratio is larger than the reference data, the skin activity is good, and if not, the skin activity is bad. This is an example divided into two cases, but it may be displayed in any number of stages according to the measurement data. Further, in this apparatus, if the biological signal detection unit 2 and the data processing / control unit 40 are accommodated in one case that can be held in the hand, and the electrode unit 101 is fixed to the outer surface of the case, the device can be used. In some cases, the measurement can be performed simply by pressing the electrode unit 101 against the subject, which facilitates the operation and is convenient for carrying and storage. According to the present embodiment, it is possible to sufficiently monitor the skin condition that causes skin inflammation, for example, atopic inflammation.
[0068]
In the above embodiments, except for the third embodiment, the electrodes are attached to the scalp and the epidermal activity of the scalp is measured, but the measurement site is the same for the earlobe, arms, feet, etc. Thus, the epidermal activity at each site can be obtained.
[0069]
【The invention's effect】
According to the invention of claim 1, since the activity of epidermal resistance is known, the activity of organs and tissues can be understood, and further, the activity of a living body can be understood.
[0070]
According to the invention of claim 2, the activity of the living body can be known visually.
[0071]
According to the invention of claim 3, the measured noise level can be viewed with reference to the reference data.
[0072]
According to the invention of claim 4, since the fact is notified when the measurement noise level is present with respect to the reference data, the operator can know the state of the measurement noise level.
[0073]
According to the invention of claim 5, the operator can know the increase in the skin resistance of the electrode mounting portion and know that it is necessary to wipe the mounting portion.
[0074]
According to the invention of claim 6, the operator can accurately know whether or not the subject is in a brain dead state.
[0075]
According to the seventh aspect of the present invention, since the brain death level is determined after sufficiently wiping the electrode mounting site, the determination result is accurate.
[0076]
According to the invention of claim 8, the skin condition of the subject can be easily known.
[0077]
According to the ninth aspect of the invention, notification and display of measurement data are performed based on a healthy person.
[0078]
In the invention of claim 10, the potential at each electrode mounting site can be accurately derived.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a bioactivity monitoring apparatus according to a first embodiment.
FIG. 2 is a perspective view showing an appearance of an electrode unit 1 used in the apparatus shown in FIG.
FIG. 3 is a flowchart for explaining the operation of the apparatus shown in FIG. 1;
4 is a view showing in detail a part of the flowchart shown in FIG. 3;
FIG. 5 is a diagram showing in detail another part of the flowchart shown in FIG. 3;
6 is a view showing data obtained by the apparatus shown in FIG. 1. FIG.
FIG. 7 is a diagram illustrating a configuration of a bioactivity monitoring apparatus according to a second embodiment.
8 is a flowchart for explaining the operation of the device shown in FIG. 7;
9 is a flowchart for explaining the operation of the apparatus shown in FIG. 7;
10 is a view for explaining the operation of the apparatus shown in FIG. 7;
11 is a flowchart for explaining the operation of the device shown in FIG. 7;
12 is a view for explaining the operation of the apparatus shown in FIG. 7;
FIG. 13 is a diagram showing a configuration of a bioactivity monitoring apparatus according to a third embodiment.
14 is a flowchart for explaining the operation of the apparatus shown in FIG. 13;
FIG. 15 is a diagram showing a result of measuring noise generated in each of a skin resistance and a fixed resistance.
FIG. 16 is a diagram showing the results of measuring noise generated as a result of measuring noise generated from earlobe, paste, water-kneaded flour, and chicken in addition to skin resistance and fixed resistance.
[Explanation of symbols]
1, 100, 101 Electrode section
2 biological signal detector
3, 30, 40 Data processing / control section

Claims (10)

A pair of electrodes attached to the epidermis of the living body;
A resistance measuring means for obtaining a resistance between the pair of electrodes;
Noise measuring means for detecting a potential difference between the pair of electrodes and converting this to a noise level;
A resistance data measured by the resistance measuring means and a measurement data storage means for storing the noise levels measured by the noise measuring means in association with each other;
A bioactivity monitor equipped with. 2. The bioactivity monitor according to claim 1, further comprising display means for displaying data based on contents stored by the measurement data storage means. A pair of electrodes attached to the epidermis of the living body;
A resistance measuring means for obtaining a resistance between the pair of electrodes;
Noise measuring means for detecting a potential difference between the pair of electrodes and converting this to a noise level;
A resistance data measured by the resistance measuring means and a measurement data storage means for storing the noise measured by the noise measuring means in association with each other;
Reference data storage means for storing reference data indicating the relationship between the resistance value of the skin resistance per predetermined area of the skin surface of the living body and the noise level resulting from the skin resistance;
Display means for displaying the content stored by the measurement data storage means and data based on the contents stored by the reference data storage means;
A bioactivity monitor equipped with. A pair of electrodes attached to the epidermis of the living body;
A resistance measuring means for obtaining a resistance between the pair of electrodes;
Noise measuring means for detecting a potential difference between the pair of electrodes and converting this to a noise level;
A resistance data measured by the resistance measuring means and a measurement data storage means for storing the noise levels measured by the noise measuring means in association with each other;
Reference data storage means for storing reference data indicating the relationship between the resistance value of the skin resistance per predetermined area of the skin surface of the living body and the noise generated from the skin resistance;
Informing means for performing predetermined notification with reference to the noise level measured by the noise measuring means and the reference data stored in the reference data storage means;
A bioactivity monitor characterized by comprising: The bioactivity monitor according to claim 4, wherein the notification means is a means for notifying that it is necessary to wipe a site where the pair of electrodes are attached. The bioactivity monitor according to claim 4, wherein the notifying means is a means for notifying that the level is a brain death level. The notification means notifies that the noise level at a certain resistance value measured by the noise measurement means is a brain death level when the noise level is within a predetermined range with respect to the noise level of the reference data at the resistance value, 5. The bioactivity monitor according to claim 4, wherein when it is outside, it is informed that it is necessary to wipe the mounting part of the pair of electrodes. 5. The bioactivity monitor according to claim 4, wherein the notifying means is means for notifying the activity of the epidermis. The bioactivity monitor according to any one of claims 3 to 8, wherein the reference data is data of a healthy person. At least three electrodes attached to the epidermis of the living body;
A resistance measuring means for obtaining a skin resistance value in the thickness direction of each part to which each of the electrodes is mounted;
A resistance value change detecting means for detecting a change in each of the skin resistance values;
A bioactivity monitor equipped with.

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