JP7437782B2 - Biological information sensor - Google Patents

Description

The present invention relates to a biological information sensor that measures biological information of a subject.

A general myoelectric sensor has an electrode part that is made up of an electrode that is brought into contact with the skin of a subject (user), and the electrode part acquires biopotentials such as myoelectric potentials that are detected by the electrode part. It has a signal processing unit that calculates biological information such as myoelectric potential waveform and muscle activity amount from the biological potential. The biological information calculated by this signal processing unit is used, for example, to control the motion of a prosthetic hand, or for medical practice or research.

In addition, there are two types of myoelectric sensors: wet-type myoelectric sensors that use wet electrodes that apply conductive electrode gel (hereinafter simply referred to as "gel") between the skin and the electrodes, and dry-type electrodes that do not use gel. They are broadly classified into dry myoelectric sensors.

A wet myoelectric sensor is composed of disposable electrodes that are replaced every time a measurement is made, a gel interposed between the skin and the electrodes, and a signal processing unit connected to the electrodes. This wet-type myoelectric sensor uses a gel between the skin and the electrode, which reduces the contact resistance between the skin and the electrode, making it easier to detect myoelectric potential (stable myoelectric potential detection is possible). become able to). As a result, by using a wet myoelectric sensor, stable biological information (biological information such as myoelectric potential waveform and muscle activity amount) can be measured.
Furthermore, wet myoelectric sensors are less affected by skin conditions such as dryness or moisture, and can reduce individual differences in measurement, making them suitable for medical practice and research.

However, although wet-type myoelectric sensors can stably measure biological information, they apply a gel to the skin, so if they are worn for a long time, the subject (user) may feel uncomfortable or the skin may become irritated. It has the problem of causing rash and itching. In addition, the wet-type myoelectric sensor has the problem that the electrodes and gel are consumables, and running costs are incurred, placing a burden on the subject (user).
Note that a gel used in a wet myoelectric sensor is disclosed in Non-Patent Document 1, for example.

On the other hand, as shown in FIG. 7, the dry myoelectric sensor 500 includes, for example, a box-shaped main body 501 made of an insulating material such as plastic, and a "tri-electrode" formed on one side of the main body 501. It has an electrode part constituted by an electrode (metallic electrode) 502, a signal processing part (not shown) connected to the electrode part, and a lead wire 503 connected to the signal processing part. There is.

This dry type myoelectric sensor is not used by applying a gel to the skin of the subject (user), so it does not cause skin irritation or itching, and compared to wet type myoelectric sensors, it does not cause skin irritation or itching. Biological information can be measured without putting any strain on the examiner's body. Furthermore, the dry type myoelectric sensor has the advantage of not incurring running costs because it does not require consumables (consumables such as electrodes and gel) like the wet type myoelectric sensor.
Furthermore, compared to wet-type myoelectric sensors, dry myoelectric sensors have the advantage of being able to use smaller electrodes, allowing for electrodes to be placed in a higher density, making it possible to acquire myoelectric potentials from small muscles. There is.
Note that the above-mentioned dry myoelectric sensor is disclosed in Non-Patent Document 2, for example.

Furthermore, although it is not used to measure myocardial potential, it has also been proposed to use cloth electrodes to measure biological information such as electrocardiograms. For example, Patent Document 1 discloses an electrode sheet in which conductive parts and non-conductive parts are knitted and woven alternately and integrally. Like the dry myoelectric sensor mentioned above, this electrode sheet (cloth electrode) does not require the use of gel, so it can measure biological information without putting strain on the subject's body, and it also increases running costs. It has the advantage of not being

BIOPAC System website, "WEB page presenting products, electrode gels and accessories", [Searched on October 18, 2021], Internet <URL: http://biopac-sys.jp/products/gel100/> Cosmo Information System Co., Ltd. WEB site, “WEB page presenting D-type dry myoelectric sensor”, [Searched on October 18, 2021], Internet <URL: http://www.cosmo-info.co.jp/ product/medjc-09/>

Japanese Patent Application Publication No. 2000-221

By the way, compared to wet-type myoelectric sensors, the dry myoelectric sensors and cloth electrodes mentioned above have the advantage of being able to measure biological information without putting any strain on the subject's body, and that there are no running costs. However, since the contact resistance between the skin and the electrode becomes high, bioelectrical potential cannot be stably detected, and as a result, bioelectrical information cannot be stably measured. Due to this problem, dry myoelectric sensors and cloth electrodes are not suitable for applications that require stable biological information, such as motion control of a prosthetic hand.

However, for example, in applications where it is necessary to wear a myoelectric sensor for a long period of time, such as in a prosthetic hand, it is desirable to be able to measure biological information without putting strain on the subject's (user) body. . Furthermore, a myoelectric sensor that does not require running costs is desired for applications such as a prosthetic hand that are used repeatedly by a subject (user).
In other words, it would be desirable to be able to stably measure biological information using dry myoelectric sensors or cloth electrodes, which have high contact resistance between the skin and electrodes. There is no known method that can stably measure biological information using dry myoelectric sensors or cloth electrodes, which have high contact resistance.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide biological information that can stably measure biological information even if the contact resistance between the subject's skin and the electrode is high. The purpose is to provide sensors.

The present invention, which has been made to solve the above problems, is a biological information sensor that is attached to a subject and measures the biological information of the subject, and the sensor is attached to the subject's skin. an electrode section that detects the biopotential of the patient; and a signal processing section that acquires the biopotential from the electrode section and calculates bioinformation from the acquired biopotential, and the signal processing section amplifies the biopotential. an amplifier and filter section that extracts only a desired frequency band; an AD conversion section that converts the biopotential of the desired frequency band extracted from the amplifier and filter section into a digital signal; a biosignal extraction filter section that extracts a biosignal corresponding to a predetermined biosignal component from the digital signal and removes a frequency component that is an integral multiple of a commercial power frequency from the extracted biosignal; and the biosignal extraction filter a biological information calculation section that calculates biological information from a biological signal signal-processed by the section, and the amplifier and filter section have a high input impedance differential amplifier function of 1 MΩ or more, and the electrode section and the signal It has a main body part provided with a processing part, the main body part is formed of a sheet-like insulating cloth, one surface of which is a contact surface to be brought into contact with the body of the subject, The electrode portion is formed by embroidering conductive thread on the insulating cloth to protrude from one side of the insulating cloth, and a button is attached to the other side of the insulating cloth by sewing with thread. A type substrate is formed, and the button type substrate has a clothing button-shaped base made of an insulating material, and a circuit board constituting the signal processing section mounted on the base, The electrode and the circuit board are electrically connected to each other by a conductive thread on the other side of the insulating cloth .

In this way, in the present invention, an amplifier that amplifies the biopotential and extracts only a desired frequency band is added to the signal processing section that acquires the biopotential detected by the electrode section and calculates bioinformation from the obtained biopotential. and a filter section. Further, the amplifier and filter section has a high input impedance differential amplifier function of 1 MΩ or more.
According to this configuration, stable biopotential can be obtained without being affected by the magnitude or fluctuation of the contact resistance between the skin and the electrode section. Therefore, according to the configuration of the present invention, biological information can be stably measured even when using a "dry myoelectric sensor or cloth electrode" that has a high contact resistance between the skin and the electrode.
In other words, according to the configuration of the present invention, compared to wet-type biological information sensors, biological information can be measured without placing a burden on the subject's body, and there is no running cost. ”, it is possible to stably measure biological information. Therefore, for example, the present invention can be used in applications where a biological information sensor must be worn for a long time, such as a prosthetic hand whose motion is controlled by biological information, thereby reducing the burden on the body of the user of the prosthetic hand. be able to.

Further, the signal processing unit includes a noise extraction filter unit that extracts a predetermined noise component from the digital signal converted by the AD conversion unit, a biological signal extracted by the biological signal extraction filter unit, and a noise extraction filter unit that extracts a predetermined noise component from the digital signal converted by the AD conversion unit. a wearing state abnormality detection section that determines whether or not the biological information sensor is correctly worn on the subject by comparing the noise component extracted by the biological information sensor with the extracted noise component; When the ratio of the noise component to the biological signal is equal to or higher than a predetermined value, it is determined that the biological information sensor is not properly attached to the subject, and when the ratio of the noise component to the biological signal is less than the predetermined value, the biological information sensor is determined to be incorrectly attached to the subject. It is desirable to determine that the sensor is correctly attached to the subject .

According to this configuration, it can be determined whether the biological information sensor is correctly attached to the subject.
For example, when using biometric information to control the motion of a prosthetic hand, the above configuration uses the calculated biometric information to control the motion of the prosthetic hand only when it is determined that the biometric information sensor is correctly attached to the subject. If it is determined that the prosthetic hand is not worn correctly, the motion of the prosthetic hand may not be controlled using the calculated biometric information. That is, according to the above configuration, it is possible to prevent the prosthetic hand from malfunctioning.
For example, when using biometric information for medical treatment (diagnosis) or research, the above configuration allows the calculated biometric information to be used only when it is determined that the biometric information sensor is correctly attached to the subject. It can be done. That is, according to the present invention, medical practices and research can be performed using accurate biological information.

Further, it is preferable that the biological potential is a myoelectric potential, and the biological information is a myoelectric potential waveform and an amount of muscle activity.

As shown in the above structure, the biological information sensor of the present invention is composed of so-called cloth electrodes. Further, the electrode portion is formed by embroidering conductive thread on the insulating cloth so as to protrude from the contact surface of the insulating cloth. In addition, a button-shaped substrate is formed on the other side of the insulating cloth and attached by sewing with a thread, and this button-shaped substrate has a button-shaped base for clothing formed of edge material, and a base of the base. It has a circuit board that constitutes a signal processing section mounted thereon.
According to this configuration, by using a sewing machine or the like, the electrode section can be formed on the insulating cloth and the circuit board constituting the signal processing section can be fixed to the insulating cloth through a simple work process. That is, according to the present invention, so-called cloth electrodes can be mass-produced at low cost.

According to the present invention, it is possible to provide a biological information sensor that can stably measure biological information even if the contact resistance between a subject's skin and an electrode is high.

1 is a schematic diagram showing the overall configuration of a biological information sensor according to an embodiment of the present invention. FIG. 1 is a schematic plan view of a biological information sensor according to an embodiment of the present invention. FIG. 1 is a schematic side view of a biological information sensor according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the flow of signals between the constituent parts of the biological information sensor according to the embodiment of the present invention. It is a flowchart showing the procedure of biological information measurement processing performed by the biological information sensor according to the embodiment of the present invention. FIG. 2 is a schematic diagram showing an example in which the biological information sensor according to the embodiment of the present invention is used to control the operation of a prosthetic hand. FIG. 2 is a schematic diagram for explaining a conventional dry myoelectric sensor.

Hereinafter, a biological information sensor according to an embodiment of the present invention will be described based on the drawings.

First, the overall configuration of the biological information sensor of this embodiment will be described with reference to FIGS. 1 to 3.

Here, FIG. 1 is a schematic diagram showing the overall configuration of the biological information sensor of this embodiment, and FIG. 2 is a schematic diagram of the biological information sensor of this embodiment viewed from above. Moreover, FIG. 3 is a schematic side view of the biological information sensor of this embodiment.

Note that FIGS. 1 to 3 show an example in which the biological information sensor W of this embodiment is constituted by cloth electrodes. In addition, in FIG. 1, as an example, the electrode unit 10 of the biological information sensor W detects a myoelectric potential (myoelectric potential signal) as a biological potential, and the signal processing unit 100 of the biological information sensor W detects the myoelectric potential from the detected myoelectric potential. A case is shown in which "biological information such as myoelectric potential waveform and muscle tone (muscle activity amount)" is calculated as information. In addition, in Figure 1, biometric information measured by a biometric information sensor is output to an external processing device such as a computer, and is used for biometric information analysis, medical treatment, and games (game application programs) that utilize biometric information. An example is shown below.

As shown in FIG. 1, the biological information sensor W of this embodiment is attached to a body part such as an arm of a subject to measure biological information of the subject.
Specifically, the biological information sensor W includes an electrode section 10 that is brought into contact with the skin of the subject to detect the subject's myoelectric potential (biopotential), and an electrode section 10 that acquires the myoelectric potential from the electrode section 10. It has a signal processing section 100 that calculates biological information from the generated myoelectric potential, and a main body section 5 in which the electrode section 10 and the signal processing section 100 are provided.

Further, as shown in FIGS. 2 and 3, the main body portion 5 is formed of a sheet-like (in the illustrated example, a rectangular sheet-like sheet-like shape in plan view) insulating cloth (non-conductive cloth), and one side thereof is covered. It is a contact surface that is brought into contact with the examiner's body.
Note that the above-mentioned insulating cloth (non-conductive cloth) includes woven fabric, knitted fabric, knitted fabric, felt, and non-woven fabric.

As shown in FIGS. 2 and 3, the electrode section 10 is composed of "three electrodes 10a, 10b, and 10c" formed by embroidering conductive threads on an insulating cloth (main body section 5). In the illustrated example, the electrodes 10a, 10b, and 10c are all rectangular with rounded corners in plan view, and have a thick shape that protrudes from the contact surface of the insulating cloth 5.

Note that in the present embodiment, the electrode section 10 has three electrodes 10a, 10b, and 10c connected to short ends of the insulating cloth (main body section 5) at one end side in the longitudinal direction (X direction) of the insulating cloth (main body section 5). They are arranged in parallel at predetermined intervals along the hand direction (Y direction).
Then, the electrode section 10 detects the myoelectric potential (biopotential) of the subject using the electrodes 10a, 10b, and 10c brought into contact with the skin of the subject, and transmits the detected muscle potential to the signal processing section 100. It is designed to transmit electrical potential.

Further, as shown in FIGS. 2 and 3, the signal processing unit 100 includes a button-shaped substrate 20 (sewn with thread and attached to the other side (opposite the contact surface) of the insulating cloth (main body 5). 20a, 20b, 20c). The button-shaped board 20 includes a clothing button-shaped base made of an insulating material and a circuit board (not shown) that constitutes the signal processing unit 100 mounted on the base.
Note that the button-shaped base for clothing is, for example, formed in a circular shape in plan view (formed in a circular shape with a diameter of about 1 cm to 4 cm), and has a plurality of through holes in its center. Like the button, it can be attached by threading a thread through the through hole and sewing it onto the insulating cloth (main body part 5).
Further, in the illustrated example, the button-shaped base is formed in a circular shape, but this is merely an example. The button-shaped base is appropriately designed depending on the purpose, such as a polygon such as a triangle, square, or hexagon, or an ellipse.

Further, on the other side of the insulating cloth 5, the electrode section 10 and a circuit board (not shown) are electrically connected by a conductive thread (or covered wire) 30. In the example shown in FIG. 2, the electrode 10a is electrically connected to a button-shaped substrate 20a by a conductive thread 30, the electrode 10b is electrically connected to a button-shaped substrate 20b by a conductive thread 30, and the electrode 10c is electrically connected to a button-shaped substrate 20b by a conductive thread 30. It is electrically connected to the substrate 20c by a conductive thread 30. Further, the button-shaped substrates 20a, 20b, and 20c are electrically connected to each other by a conductive thread (or covered wire) 33.
Further, in the illustrated example, three button-shaped substrates 20a, 20b, and 20c are provided, but the present invention is not particularly limited to this. For example, the button-shaped substrate 20 may be composed of "one button-shaped substrate" having a larger size than the button-shaped substrates 20a, 20b, and 20c. In this case, for example, a plurality of sets (for example, 3 sets) of through holes (4 through holes) to be sewn into the insulating cloth (main body part 5) are arranged at predetermined intervals on "one button-shaped board". It may be provided.

As described above, in this embodiment, the main body section 5 in which the electrode section 10 and the signal processing section 100 are provided is made of insulating cloth. Further, the electrode section 10 is formed by embroidering a conductive thread on an insulating cloth (main body section 5), and the signal processing section 100 is attached by being sewn to the other side of the insulating cloth (main body section 5). The button type board 200 is made up of a button type board 200.
According to this configuration, by using a sewing machine or the like, the electrodes 10 can be formed on the insulating cloth (main body part 5) through a simple work process, and the circuit board forming the signal processing section 10 can be attached to the insulating cloth (main body part 5). can be fixed to. That is, according to the present embodiment, it is possible to provide a biological information sensor W configured with cloth electrodes that can be mass-produced at low cost.
Furthermore, since the electrode section 10 is formed by embroidering conductive thread onto the insulating cloth 5, the shape, number, thickness, etc. of the electrodes can be customized depending on the application. Further, by using conductive thread as described above, wiring can be performed as is.

Next, the functional configuration of the signal processing section 100 will be explained.
As shown in FIG. 1, the signal processing unit 100 includes an amplifier and filter unit 110, an AD conversion unit 120, a noise extraction filter unit 130, a biological signal extraction filter unit 140, a wearing state abnormality determination unit 150, and a biological It has an information calculation section 160 and a communication processing section 170. Further, the signal processing section 100 is operated by being supplied with electric power by a power supply section (not shown). In addition, it is preferable that the above-mentioned power supply unit is insulated from an external potential and is a power supply based on a biological potential.

The amplifier and filter unit 110 receives the myoelectric potential (biopotential) transmitted from the electrode unit 10, amplifies the myoelectric potential, and extracts only a desired frequency band.
The amplifier and filter unit 110 also has a high input impedance differential amplifier function of 1 MΩ or more, an anti-aliasing low-pass filter function that transmits only low frequency components and removes high frequency components that cause aliasing noise, and a function that corresponds to the type of biopotential. It also has a high-pass filter function that removes DC components.

According to the above-mentioned "high input impedance differential amplifier function of 1 MΩ or more", it is possible to obtain a stable biopotential without being affected by the magnitude or fluctuation of the contact resistance between the skin and the electrode section 10.
In the present embodiment, the electrode section 10 is a cloth electrode composed of "three electrodes 10a, 10b, and 10c" formed by embroidering conductive thread on an insulating cloth (main body section 5), so that it does not touch the skin. Although the contact resistance between the electrode unit 10 and the electrode unit 10 increases, the myoelectric potential detected by the electrode unit 10 can be stably acquired due to the “high input impedance differential amplifier function of 1 MΩ or more” of the amplifier and filter unit 110. can.
Furthermore, by providing the amplifier and filter section 110 with an "anti-aliasing low-pass filter function" and a "high-pass filter function," it is possible to extract only the frequency band to be measured.

The AD conversion unit 120 converts the biopotential in the desired frequency band extracted by the amplifier/filter unit 110 into a digital signal. The digital signal converted by the AD conversion section 120 is transmitted to both the noise extraction filter section 130 and the biological signal extraction filter section 140.
Note that the AD conversion unit 120 uses a frequency of 300Hz, which is the least common multiple of 50Hz and 60Hz, in order to be easily applied to the process of removing commercial power frequencies (50Hz, 60Hz) by the biological signal extraction filter unit 140, which will be described later. AD conversion may be performed at a sampling rate that is an integral multiple.

The noise extraction filter section 130 extracts a signal corresponding to noise (noise component) from the digital signal converted by the AD conversion section 120. Further, the noise extraction filter section 130 transmits the extracted noise component to the wearing state abnormality detection section 150.

The biological signal extraction filter section 140 extracts a biological signal corresponding to a predetermined biological signal component from the digital signal converted by the AD conversion section 120. Furthermore, the biological signal extraction filter section 140 performs digital comb filter processing at 50 Hz and 60 Hz to remove frequency components that are integral multiples of the commercial power frequency from the extracted biological signal. In addition, the biosignal extraction filter section 140 sends a biosignal (myoelectric potential waveform (EMG )).

The wearing state abnormality detection unit 150 compares the biological signal extracted by the biological signal extraction filter unit 140 with the noise component extracted by the noise extraction filter unit 130, thereby determining whether the biological information sensor W is correctly worn on the subject. Determine whether or not the In addition, the wearing state abnormality detection unit 150 generates “wearing state information” indicating the determination result of whether or not the biological information sensor W is correctly worn on the subject, and sends the “wearing state information” to the communication processing unit 170. Send.

The biological information calculation unit 160 performs arithmetic processing (analysis processing) using the biological signal (myoelectric potential waveform (EMG)) that has been signal-processed by the biological signal extraction filter unit 140, and extracts the biological signal (myoelectric potential waveform (EMG)). Calculate muscle tone (muscle activity amount) from Furthermore, the biological information calculation unit 160 transmits the “myoelectric potential waveform (EMG) acquired from the biological signal extraction filter unit 140” and the “calculated muscle tone” to the communication processing unit 170.

The communication processing unit 170 is connected to the external processing device 300 by wire or wirelessly, and transmits “wearing state information”, “myoelectric potential waveform (EMG)” and “muscle tension” to the external processing device 300. Send.

Note that the hardware configuration of the signal processing unit 100 is not particularly limited, but may be configured as follows, for example.
Among the components of the signal processing unit 100, “the amplifier and filter unit 110 and the AD conversion unit 120” are realized by, for example, a specially designed hardware circuit.
Further, among the components of the signal processing unit 100, “the noise extraction filter unit 130, the biological signal extraction filter unit 140, the wearing state abnormality detection unit 150, the biological information calculation unit 160, and the communication processing unit 170” are, for example, This is realized by a controller unit (MCU).
In this embodiment, a circuit board including the above-described hardware circuit and MCU is mounted on a "button-shaped base for clothing" that constitutes the button-shaped board 20.

The MCU described above includes a CPU, memory (main storage, auxiliary storage), input/output interface, communication processing interface, and the like. In addition, the auxiliary storage device includes programs for realizing the functions of "noise extraction filter section 130, biological signal extraction filter section 140, wearing state abnormality detection section 150, biological information calculation section 160, and communication processing section 170". remembered. The functions of the "noise extraction filter section 130, biological signal extraction filter section 140, wearing state abnormality detection section 150, biological information calculation section 160, and communication processing section 170" are stored in the auxiliary storage device by the CPU. This is achieved by reading the program into the main memory and executing it.

Next, the biological information measurement process performed by the biological information sensor W of this embodiment will be described with reference to FIGS. 4 and 5.
Here, FIG. 4 is a schematic diagram showing the flow of signals between the constituent parts of the biological information sensor of this embodiment, and FIG. 5 is a schematic diagram showing the procedure of biological information measurement processing performed by the biological information sensor of this embodiment. FIG.

When measuring biological information using the biological information sensor W of this embodiment, as a preliminary preparation, the electrode section 10 provided on the sheet-like main body section 5 made of insulating cloth is brought into contact with the skin of the subject. The biological information sensor W is attached to the subject by wrapping and fixing it around a body part of the subject.

When the biological information sensor W is attached to the subject, the biological information sensor W is turned on (not shown). Thereby, the electrode section 10 detects myoelectric potential (biopotential) appearing on the skin of the subject. Further, the electrode section 10 transmits the detected myoelectric potential to the amplifier and filter section 110 of the signal processing section 100 (S1), and the process proceeds to S2.

In S2, the amplifier and filter section 110 receives (obtains) the myoelectric potential transmitted by the electrode section 10, amplifies the myoelectric potential, and extracts only a desired frequency band. Further, the amplifier and filter section 110 transmits the extracted myoelectric potential of the desired frequency band to the AD conversion section 120, and proceeds to the process of S3.

In S3, the AD converter 120 receives the myoelectric potential of a desired frequency band (analog signal myoelectric potential) transmitted from the amplifier/filter section 110, and converts the received myoelectric potential into a digital signal. The digital signal converted by the AD conversion section 120 is transmitted to both the noise extraction filter section 130 and the biological signal extraction filter section 140, and the process moves to S4 and S5.
Note that the processes of S4 and S5 may be performed in parallel at the same timing, or may be performed in the order of S4 and S5, or may be performed in the order of S5 and S4.

In S4, the noise extraction filter section 130 receives the digital signal transmitted from the AD conversion section 120, and extracts a predetermined noise component from the received digital signal. Further, the noise extraction filter section 130 transmits the extracted noise component to the wearing state abnormality detection section 150.

In S5, the biological signal extraction filter section 140 receives the digital signal transmitted from the AD conversion section 120, and extracts a biological signal (myoelectric potential waveform (EMG)) corresponding to a predetermined biological signal component from the received digital signal. Extract. Furthermore, the biosignal extraction filter section 140 removes frequency components that are integral multiples of the commercial power frequency from the extracted biosignal. In addition, the biological signal extraction filter section 140 sends the biological signal (myoelectric potential waveform) extracted above and from which frequency components that are integral multiples of the commercial power supply frequency removed to the wearing state abnormality detection section 150 and the biological information calculation section 160. Send EMG)).
Note that when both S4 and S5 are completed, the process of S6 is disclosed, and when the process of S5 is completed, the process of S7 is started.

In S6, the wearing state abnormality detection section 150 receives the biological signal transmitted from the biological signal extraction filter section 140, and also receives the noise component transmitted from the noise extraction filter section 130. Furthermore, the wearing state abnormality detection unit 150 determines whether the biological information sensor W is correctly worn by the subject by comparing the received biological signal and the received noise component. For example, the wearing state abnormality detection unit 150 determines that the biological information sensor W is not correctly worn by the subject when the ratio of the noise component to the biological signal (noise component/biological signal) is equal to or higher than a predetermined value. Further, when the above ratio is less than a predetermined value, it is determined that the biological information sensor W is correctly attached to the subject.
In addition, the wearing state abnormality detection unit 150 generates “wearing state information” indicating whether or not the biological information sensor W, which is the determination result, is correctly worn by the subject, and sends the generated “wearing state information” to the communication processing unit 170. "Wearing status information" is sent.

In S7, the biological information calculation section 160 receives the biological signal (myoelectric potential waveform (EMG)) transmitted from the biological signal extraction filter section 140. In addition, the biological information calculation unit 160 performs arithmetic processing (analysis processing) using the received biological signal (myoelectric potential waveform (EMG)), and calculates muscle tension (biological information) from the biological signal (myoelectric potential waveform (EMG)). ) is calculated. In addition, the biological information calculation unit 160 transmits the “myoelectric potential waveform (EMG) acquired from the biological signal extraction filter unit 140” and the “calculated muscle tone” to the communication processing unit 170.

In S8, the communication processing unit 170 receives the “wearing state information” transmitted from the wearing state abnormality detection unit 150, and also receives the “myoelectric potential waveform (EMG) and muscle tension” transmitted from the biological information calculation unit 160. receive. Furthermore, the communication processing unit 170 transmits the received “wearing state information, myoelectric potential waveform (EMG), and muscle tone” to the external processing device 300.

After that, the external processing device 300 receives the "wearing state information, myoelectric potential waveform (EMG), and muscle tone level", and the users of the external processing device 300 (doctors, researchers, game players) receive the received " Wearing status information, myoelectric potential waveforms (EMG), and muscle tension levels are used for medical practice (diagnosis), research, games (game application programs), etc. that utilize biological information.

As described above, in the biological information sensor W of this embodiment, the amplifier and filter section 110 of the signal processing section 100 is provided with a high input impedance differential amplifier function of 1 MΩ or more. With this configuration, even if the electrode part 10 is formed by embroidering conductive thread on the insulating cloth 5, that is, even if it is a cloth electrode that increases the contact resistance between the skin and the electrode part 10, , it is possible to stably acquire the myoelectric potential detected by the electrode section 10 and to stably measure biological information. As a result, according to the present embodiment, biometric information can be measured without placing a burden on the subject's body, compared to a wet biometric information sensor. Further, according to the present embodiment, there is no running cost compared to a wet biological information sensor, so the economic burden on the user is reduced.

Further, in the biological information sensor W of this embodiment, as described above, the amplifier and filter section 110 of the signal processing section 10 are provided with an anti-aliasing low-pass filter function and a high-pass filter function. Therefore, the amplifier and filter section 110 can extract only the frequency band to be measured, and the biological information can be calculated with high accuracy in the processing after S2 performed by the amplifier and filter section 110.

Further, in the biological information sensor W of this embodiment, as described above, the wearing state abnormality detection unit 150 of the signal processing unit 10 determines whether the biological information sensor W is correctly worn by the subject.
With this configuration, for example, when biometric information is used for medical treatment (diagnosis), research, or computer games (application programs), calculations are made only when it is determined that the biometric information sensor is correctly attached to the subject. Biometric information can be used. That is, according to the present embodiment, accurate biological information can be used to perform medical practices, research (research in medicine, sports science, etc.), computer games, and the like.

Furthermore, in the embodiment described above, the case where "wearing state information, myoelectric potential waveform (EMG), and muscle tension" measured by the biological information sensor W is transmitted to and used by the external processing device 300 such as a computer is shown. However, it is not particularly limited to this.

For example, as shown in FIG. 6, "wearing state information, myoelectric potential waveform (EMG), and muscle tension" measured by the biological information sensor W is transmitted to the prosthetic hand 400 and used to control the operation of the prosthetic hand. It's okay to be.
Here, FIG. 6 is a schematic diagram showing an example in which the biological information sensor of this embodiment is used to control the operation of a prosthetic hand.

A prosthetic hand 400 shown in FIG. 6 includes a signal processing section 100 of a biological information sensor W and a control circuit 410 that can communicate by wire or wirelessly. This control circuit 410 receives "wearing state information, myoelectric potential waveform (EMG), and muscle tension" from the biological information sensor W, and the received "wearing state information, myoelectric potential waveform (EMG), and muscle tension" The motion of the prosthetic hand 400 is controlled using the following.

Furthermore, when the received "wearing state information" is "information indicating that the biological information sensor W is correctly worn on the subject," the control circuit 410 controls the received "myoelectric potential waveform (EMG) and muscle tension." The motion of the prosthetic hand 400 is controlled using the "degree".
In addition, when the received "wearing state information" is "information indicating that the biological information sensor W is not correctly worn on the subject," the control circuit 410 controls the received "myoelectric potential waveform (EMG) and muscle tension." The operation of the prosthetic hand 400 is not controlled using "degree". With this configuration, it is possible to control the operation of the prosthetic hand using biological information measured when the biological information sensor W is not properly attached to the subject, that is, biological information that is estimated to have not been accurately measured. (For example, it is possible to prevent a prosthetic hand from malfunctioning.)

Furthermore, according to the configuration shown in FIG. 6, the user of the prosthetic hand 400 who requires biometric information for a long time can use the prosthetic hand 400 more easily than when using a wet biometric information sensor because the biometric information is measured by the cloth electrode. It is possible to reduce the burden on the person's body.
Furthermore, the biological information sensor W for controlling the operation of the prosthetic hand 400 is used repeatedly by the user of the prosthetic hand, but it is not a disposable electrode like a wet biological information sensor and does not require gel. Therefore, there are no running costs and the economic burden is reduced.

As described above, the present embodiment provides a biological information sensor W that can stably measure biological information even if the contact resistance between the subject's skin and the electrode is high. be able to.

Note that the present invention is not limited to the embodiments described above, and various changes can be made within the scope of the invention.

For example, in the embodiment described above, a case has been described in which the biological information sensor W is constituted by cloth electrodes, but the present invention can be applied to devices other than cloth electrodes.
For example, the signal processing section (not shown in FIG. 7) of the conventional "dry biological information sensor 500" shown in FIG. 7 may be replaced with the signal processing section 100 of this embodiment. Although the dry biological information sensor 500 has a high contact resistance between the subject's skin and the electrode, by providing the signal processing section 100 of this embodiment, it is possible to stably measure biological information. become able to.
Further, in the dry myoelectric sensor 500 shown in FIG. 7, an electrode 502 provided on one side of a box-shaped main body 501 made of an insulating material is made of metal, but this is not particularly limited. It's not a thing. The electrode 502 of the dry myoelectric sensor 500 may be made of a "conductive material (eg, conductive plastic)" other than metal.

Furthermore, in the biological information sensor W of the embodiment described above, the electrode section 10 detects myoelectric potential, and the signal processing section 100 calculates "wearing state information, myoelectric potential waveform (EMG), and muscle tone" from the myoelectric potential. However, it is not particularly limited to this. The electrode unit 10 of the biological information sensor W may detect a biological potential other than myoelectric potential, and calculate biological information other than "myoelectric potential waveform (EMG) and muscle tone" from the biopotential.

Furthermore, in the biological information sensor W of the embodiment described above, the button-shaped board 20 on which a circuit board for realizing the function of the signal processing part 100 is mounted is attached to the main body part 5 formed of an insulating cloth. This configuration is an example. The function of the signal processing section 100 may be provided in a separate device (for example, a device such as a computer) electrically connected to the electrode section 10.

Furthermore, although the biological information sensor W of the embodiment described above has a main body portion 5 made of an insulating cloth, the main body portion 5 may be made of a “sheet-like insulating material” other than the insulating cloth. It's okay.

W... Biological information sensor 5... Main body part 10... Electrode parts 10a, 10b, 10c... Electrodes 20, 20a, 20b, 20c... Button type substrates 30, 33... Conductive thread 100... Signal processing part 110... Amplifier and filter part 120 ...AD conversion section 130...Noise extraction filter section 140...Biological signal extraction filter section 150...Wearing state abnormality determination section 160...Biological information calculation section 170...Communication processing section 300...External processing device 400...Prosthetic hand 410...Control circuit

Claims (4)

A biological information sensor that is attached to a subject and measures biological information of the subject,
an electrode part that is brought into contact with the skin of the subject to detect the biopotential of the subject;
a signal processing unit that acquires the biopotential from the electrode unit and calculates bioinformation from the acquired biopotential,
The signal processing section includes:
an amplifier and filter unit that amplifies the biopotential and extracts only a desired frequency band;
an AD conversion unit that converts the biopotential in the desired frequency band extracted from the amplifier and filter unit into a digital signal;
A biosignal extraction filter unit that extracts a biosignal corresponding to a predetermined biosignal component from the digital signal converted by the AD conversion unit, and removes frequency components that are integral multiples of the commercial power frequency from the extracted biosignal. and,
a biological information calculation unit that calculates biological information from the biological signal signal-processed by the biological signal extraction filter unit,
The amplifier and filter section has a high input impedance differential amplifier function of 1 MΩ or more,
comprising a main body section in which the electrode section and the signal processing section are provided;
The main body portion is formed of a sheet-like insulating cloth, and one side thereof is a contact surface that is brought into contact with the body of the subject,
The electrode portion is formed by embroidering conductive thread on the insulating cloth so as to protrude from one side of the insulating cloth,
A button-shaped substrate is formed on the other side of the insulating cloth and is attached by sewing with a thread,
The button-shaped board has a clothing button-shaped base made of an insulating material, and a circuit board constituting the signal processing unit mounted on the base,
A biological information sensor , wherein the electrode and the circuit board are electrically connected to each other by a conductive thread on the other side of the insulating cloth . The signal processing section includes:
a noise extraction filter unit that extracts a predetermined noise component from the digital signal converted by the AD conversion unit;
Wearing that determines whether or not the biological information sensor is correctly worn on the subject by comparing the biological signal extracted by the biological signal extraction filter section and the noise component extracted by the noise extraction filter section. It has a state abnormality detection section,
The wearing state abnormality detection unit determines that the biological information sensor is not correctly worn on the subject when the ratio of the noise component to the biological signal is equal to or higher than a predetermined value, and determines that the ratio of the noise component to the biological signal is higher than a predetermined value. The biological information sensor according to claim 1 , wherein when the value is less than a predetermined value, it is determined that the biological information sensor is correctly attached to the subject . A biological information sensor that is attached to a subject and measures biological information of the subject,
an electrode part that is brought into contact with the skin of the subject to detect the biopotential of the subject;
a signal processing unit that acquires the biopotential from the electrode unit and calculates bioinformation from the acquired biopotential,
The signal processing section includes:
an amplifier and filter unit that amplifies the biopotential and extracts only a desired frequency band;
an AD conversion unit that converts the biopotential in the desired frequency band extracted from the amplifier and filter unit into a digital signal;
A biosignal extraction filter unit that extracts a biosignal corresponding to a predetermined biosignal component from the digital signal converted by the AD conversion unit, and removes frequency components that are integral multiples of the commercial power frequency from the extracted biosignal. and,
a biological information calculation unit that calculates biological information from the biological signal processed by the biological signal extraction filter unit ;
a noise extraction filter unit that extracts a predetermined noise component from the digital signal converted by the AD conversion unit;
Wearing that determines whether or not the biological information sensor is correctly worn on the subject by comparing the biological signal extracted by the biological signal extraction filter section and the noise component extracted by the noise extraction filter section. It has a state abnormality detection section,
The amplifier and filter section has a high input impedance differential amplifier function of 1 MΩ or more,
The wearing state abnormality detection unit determines that the biological information sensor is not correctly worn on the subject when the ratio of the noise component to the biological signal is equal to or higher than a predetermined value, and determines that the ratio of the noise component to the biological signal is higher than a predetermined value. A biological information sensor characterized in that when it is less than a predetermined value, it is determined that the biological information sensor is correctly attached to the subject . the biopotential is a myoelectric potential,
The biological information sensor according to any one of claims 1 to 3, wherein the biological information is a myoelectric potential waveform and an amount of muscle activity.

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