JP7303534B2 - smart wear - Google Patents

Description

The present invention relates to smart wear capable of measuring a wearer's electrocardiogram and other biological information just by wearing it.

In recent years, in various fields, wearable devices, which are computer devices worn on the body for use, have attracted attention. Among them, one of the promising fields is bioinstrumentation, which is mainly applied to healthcare and sports. If wearable devices can easily measure biological information, it can be expected to be applied to physical condition management in daily life, exercise management for health maintenance, etc., as well as training intensity management and effect evaluation at sports sites. Among such wearable devices, clothing-type wearable devices that can measure the wearer's biological information just by wearing them are called smart wear.

In the above technical field, Patent Document 1 discloses that three electrodes are fixed to specific positions on the back side of clothing, and the electrodes are attached to specific positions on the wearer's body simply by wearing the clothing. Disclosed is an electrocardiogram measurement garment that can be brought into contact with the wearer's electrocardiogram to measure the electrocardiogram. An electrocardiogram is biological information that shows, in the form of a waveform, changes in electrical potential caused by cardiac activity. In addition, the heart rate can be calculated from the electrocardiogram, and the load on the body during exercise can be evaluated based on the heart rate, and the activity of the autonomic nervous system can be evaluated based on the fluctuation of the heart rate. In the general electrocardiogram measurement method, measurement is performed by attaching disposable electrodes to specific positions of the body with adhesive materials such as tape or adhesive gel. There was a problem such as a skin rash due to the adhesive material. The electrocardiogram measurement garment of Patent Document 1 solves such problems, and allows the electrocardiogram to be measured simply by wearing it.

On the other hand, although it is not a wearable device, Patent Literature 2 discloses a biological signal measuring device capable of simultaneously acquiring heartbeat information and respiration information using the same two electrodes. Heart rate information is information such as electrocardiogram waveforms and heart rate, and can be obtained by measuring biopotential. Respiration information is information such as breathing rate, breathing depth, and presence or absence of breathing, and is obtained by measuring the bioimpedance of the chest. It reveals what it can do. In the biosignal measurement device of Patent Document 2, two stick-type electrodes such as disposable electrodes are installed on the user's chest, and the two electrodes are used to measure biopotential and bioimpedance. By performing time-division measurement by switching at the timing of , and interpolating each non-measured time interval from each measured data, different biological information such as heartbeat information and respiration information can be acquired. there is

JP 2017-093997 A Japanese Patent No. 5587524

As described above, Patent Literature 1 discloses smart wear that can easily measure an electrocardiogram. However, Patent Document 1 does not disclose acquisition of biological information other than an electrocardiogram. If smartwear can measure not only one biological information such as an electrocardiogram, but also other biological information, it will be more useful, such as making a composite evaluation using multiple biological information. . In order to do so, it is generally thought that the number of electrodes serving as sensors should be increased according to the biological information to be acquired, but in the case of smartwear, increasing the number of electrodes makes wearing comfort worse. It is preferable that the number of electrodes is as small as possible, because it leads to an increase in cost and an increase in cost.

Patent Literature 2 discloses that a plurality of pieces of biological information such as heartbeat information and respiration information can be obtained by measuring biopotential and bioimpedance with two electrodes set on the chest. However, in Patent Document 2, although the biopotential and the bioimpedance are measured with two electrodes, the biopotential and the bioimpedance are measured alternately in a time division manner, and the missing time segments are supplemented by estimation by interpolation processing. Therefore, biopotential and bioimpedance could not be measured at the same time. When the biopotential and the bioimpedance are alternately measured and interpolated, the control of switching timing becomes complicated, and an error may occur in the estimation by the interpolated process.

SUMMARY OF THE INVENTION It is an object of the present invention to provide smart wear capable of simultaneously measuring biopotential and bioimpedance using two electrodes.

In order to solve the above problems, the smart wear according to the present invention includes clothes worn by a wearer, a first electrode provided on the clothes so as to come into contact with the wearer's body when the clothes are worn, and a second electrode; current applying means for applying a measuring current for measuring bioimpedance between the first electrode and the second electrode; a potential difference measuring means for measuring the inter-electrode potential difference between the first electrode and the second electrode in the state applied between the second electrodes; and biopotential obtained from the inter-electrode potential difference measured by the potential difference measuring means. and a frequency corresponding to the potential difference for calculation used to calculate the bioimpedance generated by applying the current for measurement from the potential difference between the electrodes measured by the potential difference measuring means. and bioimpedance calculation means for calculating the bioimpedance based on the potential difference for calculation extracted by the second frequency filter, wherein the first frequency filter is 10 Hz to 1000 Hz. a band-pass filter that passes a signal with a frequency of 1000 Hz or less, a secondary low-pass filter that passes a signal with a frequency of 1000 Hz or less, and an inverting amplifier circuit that amplifies the electrical signal that has passed through the secondary low-pass filter, and the potential difference The electrical signal input from the measuring means to the first frequency filter passes through the hand-pass filter, the secondary low-pass filter, and the inverting amplifier circuit in order, and the second frequency filter is a secondary high-pass filter. , a primary low-pass filter (642) that passes signals of 200 kHz or less , a full-wave rectifier circuit that obtains the absolute value of the signal output from the primary low-pass filter (642) , and a signal of 10 Hz or less that passes through. and a non-inverting amplifier circuit that amplifies the electrical signal input from the primary low-pass filter (644), and the electrical signal input from the potential difference measuring means to the second frequency filter The electrical signal is passed through the secondary high-pass filter, the primary low-pass filter (642) that passes signals of 200 kHz or less , the full-wave rectifier circuit, the primary low-pass filter (644) that passes signals of 10 Hz or less , and the It is characterized by sequentially passing through a non-inverting amplifier circuit.

Preferably, the garment is worn on the upper half of the wearer's body, and the first electrodes are positioned on the front rib center line of the wearer's body, the left anterior axillary line, and the top of the fifth rib. , the garment so as to abut on any position within the region surrounded by the lower end of the eighth rib, and the second electrode is positioned between the center line of the rib on the front surface of the wearer's body and the right front It is provided on the garment so as to contact any position within a region surrounded by the axillary line, the upper end of the fifth rib, and the lower end of the eighth rib.

Preferably, the wearer further comprises respiration acquisition means for acquiring respiration information of the wearer based on the bioelectrical impedance calculated by the bioelectrical impedance calculation means.

Preferably, the wearer further comprises cardiac output acquisition means for acquiring cardiac output information of the wearer based on the bio-impedance calculated by the bio-impedance calculation means.

Preferably, it is characterized by comprising electrocardiogram acquisition means for acquiring an electrocardiogram of the wearer based on the biopotential extracted by the first frequency filter.

Preferably, the garment further comprises a ground electrode provided on the garment so as to abut on the wearer's body when the garment is worn.

According to the smart wear of the present invention, the first electrode and the second electrode are provided on the clothes, and when the wearer wears the clothes, the first electrode and the second electrode come into contact with the wearer's body. It's like Then, by the current applying means, a measurement current for measuring bioimpedance is applied between the first electrode and the second electrode in contact with the body of the wearer, and by the potential difference measuring means, the first electrode and the second electrode are applied. The inter-electrode potential difference between the two electrodes is measured. Here, the inter-electrode potential difference measured by the potential difference measuring means is a state in which the biopotential generated by the activity of the living body and the potential difference for calculation used to calculate the bioimpedance generated by the application of the current for measurement by the current applying means are mixed. It has become. A first frequency filter extracts a frequency component corresponding to the biopotential from this inter-electrode potential difference. Further, the second frequency filter extracts a frequency component corresponding to the potential difference for calculating the bioimpedance from the potential difference between the electrodes, and the bioimpedance calculating means calculates the bioimpedance based on the potential difference for calculation extracted by the second frequency filter. Calculate the impedance. Therefore, according to the smart wear of the present invention, the two electrodes, ie, the first electrode and the second electrode, can simultaneously measure biopotential and bioimpedance. In addition, since the smart wear according to the present invention is a clothing type, it is possible to measure the biopotential and bioimpedance simply by wearing it and while it is being worn. can be measured.

Preferably, the clothes worn on the wearer's upper body are provided with the first electrode and the second electrode. The biopotential of the chest and the bioimpedance of the chest can be measured simultaneously.

Preferably, the breathing acquisition means for acquiring the wearer's respiration information based on the bioimpedance calculated by the bioimpedance calculation means is provided. Respiratory information such as depth can be acquired, and respiration can be monitored over a long period of time, so it can be used to detect respiratory diseases. In addition, it can be used for evaluation of exercise load based on breathing information during exercise.

Preferably, the smartwear according to the present invention is equipped with a cardiac output acquiring means for acquiring information on the wearer's cardiac output based on the bioimpedance calculated by the bioimpedance calculating means. Cardiac output information, such as blood volume, can be obtained from heartbeats at an early stage, and cardiac output can be monitored over a long period of time. It can also be used for evaluation of exercise load, etc., based on cardiac output information during exercise.

Preferably, an electrocardiogram acquisition means is provided for acquiring an electrocardiogram of the wearer based on the biopotential extracted by the first frequency filter. Since the electrocardiogram can be monitored over a period of time, it can be used to detect heart disease. In addition, since the heart rate can be calculated from the acquired electrocardiogram, the heart rate during exercise can be used to evaluate the exercise load.

Preferably, the apparatus further includes a ground electrode provided on the clothing so as to abut on the wearer's body when the clothing is worn, so noise in the biopotential and bioimpedance to be measured can be reduced.

1 is a schematic external view of smart wear according to an embodiment of the present invention; FIG. 1 is a block diagram showing the configuration of smartwear according to an embodiment of the present invention; FIG. FIG. 4 is a circuit diagram of a current applying means used in an example of smart wear according to one embodiment of the present invention. FIG. 2 is a circuit diagram of potential difference measuring means, first frequency filter, and second frequency filter used in an example of smart wear according to one embodiment of the present invention. FIG. 4 shows the results of measuring a known resistance in an example of smartwear according to one embodiment of the present invention. FIG. 3 is a diagram of waveforms showing changes in bioimpedance corresponding to electrocardiogram waveforms and respiration information measured by an example of smart wear according to one embodiment of the present invention. FIG. 4 is a diagram of waveforms showing changes in bioimpedance corresponding to electrocardiogram waveforms and cardiac output information measured by an example of smart wear according to one embodiment of the present invention.

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1 , smartwear 1 according to this embodiment includes clothes 2 , first electrodes 3 and second electrodes 4 provided on clothes 2 , and measuring device 6 attached to clothes 2 . According to the smartwear 1, when the wearer puts on the garment 2, the first electrode 3 and the second electrode 4 come into contact with specific positions on the wearer's body. The measuring device 6 simultaneously measures the wearer's biopotential and bioimpedance using two electrodes, the first electrode 3 and the second electrode 4, which are in contact with the wearer's body, and acquires a plurality of biometric information. be able to. Each component will be described in detail below.

The clothes 2 are clothes worn by the wearer, and underwear that directly touches the wearer's body is preferably used. Also, the clothes 2 are made of stretchable fabric so as to be in close contact with the wearer's body and maintain the close contact with the movements of the wearer's body even when the wearer moves his/her body. is preferred. In this embodiment, an example is shown in which a shirt, which is an undergarment worn on the trunk of the wearer's upper body, is used as the garment 2 .

The first electrode 3 and the second electrode 4 are fixed to the garment 2 so as to abut on specific positions on the wearer's body when the garment 2 is put on by the wearer. The first electrode 3 and the second electrode 4 are electrodes used for measuring biopotential and bioimpedance, and are always in contact with the wearer's body when the wearer is wearing the clothes 2 . Therefore, the first electrode 3 and the second electrode 4 are dry electrodes that are less likely to cause skin rash or the like even if they are in contact with the wearer's body for a long time, and that cause less discomfort during contact. The first electrode 3 and the second electrode 4 are arranged so that the first electrode 3 and the second electrode 4 provided on the clothing 2 are also brought into contact with the wearer's body when the clothing 2 is brought into close contact with the wearer. . Therefore, the first electrode 3 and the second electrode 4 are made of a thin and flexible material so that they can expand and contract following the expansion and contraction of the clothing 2 even when the clothing 2 expands and contracts due to body movement of the wearer. It is preferred that the film is highly elastic and has high electrical conductivity even when stretched. Examples of such electrodes having both stretchability and conductivity include textile electrodes obtained by weaving or sewing conductive fibers into cloth, polymer electrodes using a conductive polymer material as an electrode material, PEDOT-PSS, and the like. There is an electrode or the like in which cloth is impregnated with a conductive polymer, and these electrodes can be used as the first electrode 3 and the second electrode 4 .

The first electrode 3 and the second electrode 4 are connected to the measuring device 6 by wiring 31 and wiring 41, respectively. The wiring 31 and the wiring 41 do not necessarily need to be fixed to the clothes 2, but are preferably fixed to the clothes 2 in order to prevent disconnection due to being caught on something. When the wiring 31 and the wiring 41 are fixed to the clothing 2, the wiring 31 and the wiring 41 are also formed of a material having both elasticity and conductivity, like the first electrode 3 and the second electrode 4. is preferred.

In this embodiment, the first electrode 3, the second electrode 4, the wiring 31, and the wiring 41 are made of a material formed by sandwiching a conductive film having high conductivity and stretchability between two insulating films. COCOMI (registered trademark) of Toyobo Co., Ltd. is used. The first electrode 3 and wiring 31 , and the second electrode 4 and wiring 41 are each integrally formed and fixed to the back side of the clothing 2 . Among them, the portions corresponding to the first electrode 3 and the second electrode 4 are removed from the insulating film on the body side of the wearer to expose the conductive film, and the exposed conductive film is the first electrode 3 and the second electrode 4. It abuts on the wearer's body as the second electrode 4 . The portions corresponding to the wiring 31 and the wiring 41 are respectively kept insulated from the outside by an insulating film, and the wiring 31 and the wiring 41 are interposed between the first electrode and the second electrode 4 and the measuring device 6. can exchange electrical signals. Since the first electrode 3 and the wiring 31 and the second electrode 4 and the wiring 41 are integrally formed, there is no step at the connection between the electrode portion and the wiring portion, and the contact with the body of the wearer is prevented. Discomfort due to steps when in contact can be eliminated.

The first electrode 3 and the second electrode 4 may be fixed to the clothing 2 so as to abut on the wearer's body position suitable for obtaining the biological information according to the biological information to be obtained. In this embodiment, an example is shown in which two electrodes, the first electrode 3 and the second electrode 4, are used to acquire three biological information simultaneously, ie, an electrocardiogram, respiratory information, and cardiac output information. An electrocardiogram is biological information that represents, in the form of a waveform, changes in potential caused by cardiac activity. It can be obtained by measuring the biopotential between the electrode 3 and the second electrode 4 . Respiration information is biological information related to respiration, such as respiration rate and respiration depth. Air has lower electrical conductivity than tissues and body fluids in the body, and air is taken into and out of the lungs by respiration. As a result, the bioimpedance representing the electrical resistance of the chest changes, so the first electrode 3 and the second electrode 4 are placed on the chest, and the bioimpedance between the first electrode 3 and the second electrode 4 is measured. can be obtained by Cardiac output information is biological information about the amount of blood pumped out by the heartbeat. Blood has a higher electrical conductivity than other tissues in the body, and the pumping of blood from the heart increases the volume of the heart. Since the bioimpedance representing the electrical resistance of the surrounding chest varies, the first electrode 3 and the second electrode 4 are placed on the chest to measure the bioimpedance between the first electrode 3 and the second electrode 4. can be obtained with Therefore, the 1st electrode 3 and the 2nd electrode 4 are provided so that a wearer's chest may be contact|abutted. The first electrode 3 is located on the left side of the center of the wearer's chest, and the second electrode 3 is located on the right side of the center of the wearer's chest so that the wearer's heart and lungs are sandwiched between the first electrode 3 and the second electrode 4 . Preferably, the electrodes 4 are provided so as to contact each other. The first electrode 3 is placed at any position within the region surrounded by the center line of the ribs on the front of the wearer's body, the left anterior axillary line, the upper end of the fifth rib, and the lower end of the eighth rib. Further, the second electrode 4 is provided at any position within the region surrounded by the center line of the front rib, the right anterior axillary line, the upper end of the fifth rib, and the lower end of the eighth rib so as to be in contact with each other. preferable.

A ground electrode 5 may be provided separately from the first electrode 3 and the second electrode 4 . The ground electrode 5 is not an electrode used for measuring biopotential and bioimpedance, but an electrode used as a ground for acquiring an electrocardiogram or the like with less noise. The ground electrode 5 is fixed to the clothes 2 and provided so as to come into contact with the wearer's body when the wearer puts on the clothes 2 . The ground electrode 5 is such that the potential of the wearer's body is less likely to fluctuate and, as will be described later, is less likely to be affected by the current for measurement by the current applying means 61 applied to the first electrode 3 and the second electrode. It is preferably provided so as to abut on a position, for example, on a bone away from the first electrode 3 and the second electrode 4 and on which little biopotential is generated. For example, when the first electrode 3 and the second electrode 4 are provided to contact the left and right ribs of the lower sternum, the ground electrode 5 may be provided to contact the upper part of the sternum. . The ground electrode 5 is connected to the measuring device 6 by wiring 51 . The ground electrode 5 and the wiring 51 may be made of the same material as the first electrode 3 and the second electrode 4 .

The measuring device 6 is a device that acquires electrical signals from the first electrode 3 and the second electrode 4 and measures biopotential and bioimpedance. As shown in FIG. 1 , the measuring device 6 is detachably attached to the front side of the clothing 2 . When the measuring device 6 is attached to the clothing 2 , the measuring device 6 is connected to the wiring 31 and the wiring 41 . When the ground electrode 5 is provided, the measuring device 6 is also connected to the wiring 51 .

As shown in FIG. 2, the measuring device 6 includes a measuring section 60, a control section 71, a storage section 72, and a communication section 73, each of which is configured to exchange data with each other via a bus 74. ing. The measurement unit 60 measures biopotential and bioimpedance to obtain biometric information. The storage unit 72 stores various programs and the like used by the measurement unit 60 to acquire biological information, and also stores data measured by the measurement unit 60 and acquired data. The communication unit 73 is wirelessly or wiredly connected to an external information terminal such as a smartphone or a personal computer, and transmits and receives various data such as biological information data acquired by the measurement unit 60 . The control unit 71 controls the measurement unit 60 , the storage unit 72 and the communication unit 73 , and the functions of each unit are executed under the control of the control unit 71 .

The measuring unit 60 includes a current applying means 61, a potential difference measuring means 62, a first frequency filter 63, a second frequency filter 64, an electrocardiogram acquiring means 65, a bioimpedance calculating means 66, a respiration acquiring means 67, and cardiac output acquisition means 68 .

The current applying means 61 applies a measurement current to the first electrode 3 and the second electrode 4 for measuring bioimpedance. Since the first electrode 3 and the second electrode 4 are in contact with the wearer's body, the measurement current applied by the current applying means 61 is applied from one of the first electrode 3 and the second electrode 4 to the wearer's body. flows through the body of At this time, depending on the magnitude of the bio-impedance representing the electrical resistance in the wearer's body between the first electrode 3 and the second electrode 4, the bio-impedance generated between the first electrode 3 and the second electrode 4 by the measurement current The calculation potential difference for calculating the impedance changes. Therefore, by measuring the potential difference for calculation between the first electrode 3 and the second electrode 4, the bioimpedance of the wearer between the first electrode 3 and the first electrode 3 can be calculated. The measurement current applied by the current applying means 61 is an alternating current having a frequency of about 10 kHz to 100 kHz and a constant current having an effective value of 0.1 mA or less. The current applying means 61 may have an oscillator circuit for generating this constant current. The frequency of the biopotential, which is an electrical signal generated by living body activity, is approximately 2 kHz or less (from about 0.5 kHz to 100 Hz in an electrocardiogram), and the electrical signal resulting from the biopotential and the electrical signal for calculating the bioimpedance will be used later. , the measurement current applied by the current applying means 61 has a clearly higher frequency than that. When a current with an effective value of 1 mA or more is applied, the human body will feel the current. This enables long-term measurement without making the wearer aware of the application of current.

The potential difference measuring means 62 measures the inter-electrode potential difference between the first electrode 3 and the second electrode 4 . The inter-electrode potential difference measured by the potential difference measuring means 62 is a calculation potential difference for calculating the bioimpedance generated between the first electrode 3 and the second electrode 4 by the measurement current of the current applying means 61, and the wearer's potential difference. A potential difference corresponding to the biological potential generated between the first electrode 3 and the second electrode 4 due to biological activity is mixed. The potential difference measuring means 62 may have an amplifier for amplifying the potential difference between the electrodes. When the ground electrode 5 is provided, the potential difference measuring means 62 calculates the inter-electrode potential difference with reduced noise from the potential difference of the first electrode 3 with respect to the ground electrode 5 and the potential difference of the second electrode 4 with respect to the ground electrode 5. can be measured. A signal of the inter-electrode potential difference measured by the potential difference measuring means 62 is output to the first frequency filter 63 and the second frequency filter 64, respectively.

The first frequency filter 63 extracts a frequency component corresponding to the biological potential from the inter-electrode potential difference measured by the potential difference measuring means 62 . As described above, the frequency component corresponding to the biopotential has a low frequency of approximately 2 kHz or less. The current for measurement applied by the current applying means 61 is a constant current with a frequency higher than the biopotential of 10 kHz to 100 kHz, and the frequency of the potential difference for calculating bioimpedance generated by the current for measurement also corresponds to the current for measurement. It has a high frequency. Therefore, the first frequency filter 63 passes a frequency component of, for example, 2 kHz or less, which passes a low frequency component corresponding to the biopotential and blocks a high frequency component corresponding to the potential difference for bioimpedance calculation. It may have a low pass filter. Further, in this embodiment, an electrocardiogram is obtained from a biopotential, so the first frequency filter 63 may have an amplifier circuit that amplifies a frequency band corresponding to the electrocardiogram, eg, 10 Hz to 200 Hz. The signal that has passed through the first frequency filter 63 is sent to the electrocardiogram acquiring means 65 .

The second frequency filter 64 extracts a frequency component corresponding to the potential difference for bioimpedance calculation from the inter-electrode potential difference measured by the potential difference measuring means 62 . The second frequency filter 64 is a high-pass filter that cuts off low frequency components corresponding to the biopotential and passes high frequency components corresponding to the potential difference for calculating bioimpedance, for example, passing frequency components of 10 kHz or higher. may have Also, the second frequency filter 64 may have an amplifier circuit that amplifies a frequency band corresponding to the potential difference for bioimpedance calculation, eg, 10 kHz to 200 kHz. The signal that has passed through the second frequency filter 64 is sent to the bioimpedance calculator 66 .

The electrocardiogram acquiring means 65 analyzes the potential difference signal of the frequency component corresponding to the biopotential sent from the first frequency filter 63 and acquires an electrocardiogram. The electrocardiogram acquisition means 65 may have an A/D converter that converts the potential difference signal sent from the first frequency filter 63 into a digital signal. An electrocardiogram is biological information that expresses changes in potential that occur in cardiac activity as a waveform, and can be obtained as a waveform by plotting potential differences in frequency components corresponding to the biological potential sent from the first frequency filter 63 over time. . The electrocardiogram acquired by the electrocardiogram acquisition means 65 is stored in the storage unit 72 and transmitted to an external information terminal via the communication unit 73 so that the waveform of the electrocardiogram can be displayed on the information terminal. In addition, the electrocardiogram acquisition means 65 may have heart rate calculation means for calculating the heart rate from the electrocardiogram. An electrocardiogram mainly shows P-wave, Q-wave, R-wave, S-wave and T-wave waveforms due to one heartbeat. Among them, the R wave is a waveform representing ventricular activity and generally has the largest amplitude. Therefore, the duration of one heart beat can be calculated from the time between peaks of adjacent R waves. Since the heart rate is the number of heart beats per unit time, generally one minute, it can be calculated by dividing the unit time by the duration of one heart beat. The electrocardiogram acquisition means 65 may have a frequency filter for further acquiring a target waveform from the waveform of the electrocardiogram. For example, if the purpose is to acquire the R wave, which is important for heart rate calculation, it may have a bandpass filter that passes 10 Hz to 100 Hz, for example. As a result, noise signals other than signals corresponding to the target information can be reduced from the electrocardiogram signal, and target information with less error can be obtained.

The bioimpedance calculator 66 calculates the bioimpedance based on the potential difference signal of the frequency component corresponding to the bioimpedance calculation potential difference sent from the second frequency filter 64 . The bioimpedance calculator 66 may have an A/D converter that converts the signal of the potential difference for calculation sent from the second frequency filter 64 into a digital signal. The bioimpedance represents the electrical resistance of the living body, and the bioimpedance can be calculated from the current for measurement applied by the current applying means 61 and the potential difference for calculation.

The respiration acquisition means 67 acquires respiration information based on the bio-impedance calculated by the bio-impedance calculation means 66 . As the wearer breathes, air is drawn in and out of the wearer's lungs. Air has lower electrical conductivity than tissues and body fluids in the body, so when air is inhaled into the lungs by respiration, the bioimpedance of the chest increases, and when air is expelled from the lungs, the bioimpedance of the chest increases. lower. Therefore, when the bioimpedance calculated by the bioimpedance calculating means 66 is plotted against time, a waveform appears in which the bioimpedance changes periodically with respiration. Respiration information such as can be acquired. A general breathing rate is about 12 to 18 times per minute at rest, and the frequency is about 0.2 Hz to 0.3 Hz. Since it moves up and down with the movement, the waveform has a frequency corresponding to the respiratory rate. The respiration rate can be calculated from the number of up and down movements of the bioimpedance associated with respiration that appears in a unit time, generally one minute, and the rise in bioimpedance when air is inhaled can be used to calculate the number of times of one cycle. It is possible to calculate the amount of air inhaled. The bio-impedance calculation means 66 has a band-pass filter having a frequency characteristic of passing a signal in a frequency band corresponding to the frequency of respiration, for example, 0.01 Hz to 2 Hz, with respect to the signal sent to the respiration acquisition means 67. You may have As a result, noise signals other than signals corresponding to respiration can be reduced from the bioimpedance calculated by the bioimpedance calculator 66, and respiration information with less error can be obtained.

Cardiac output acquisition means 68 acquires cardiac output information based on the bioimpedance calculated by bioimpedance calculation means 66 . As the heart beats, blood is pumped out of the heart. Blood has a higher electrical conductivity than other tissues in the body, so when the blood is pumped out of the heart and the blood in the heart decreases, the bioimpedance of the chest around the heart becomes low, and before the blood is pumped out of the heart The bioimpedance of the thoracic region around the heart is high when blood is pooling in the heart. Therefore, when the bioimpedance calculated by the bioimpedance calculating means 66 is plotted against time, a waveform appears in which the bioimpedance changes periodically with the pulsation of the heart. Cardiac output, which is the amount of blood pumped in a unit of time, generally one minute, stroke volume, which is the amount of blood pumped in one heart beat, and the period of the heart beat Cardiac output information such as heart rate and heart rate can be obtained. A general heart rate is about 60 to 80 beats per minute at rest, and the frequency is about 1 Hz to 1.3 Hz, and the bioimpedance waveform for obtaining cardiac output information is Since it moves up and down with the beat of the heart, the waveform has a frequency corresponding to the heart rate. The heart rate can be calculated from the number of fluctuations in the bioimpedance associated with the heartbeat that appears per unit time, generally one minute, and the drop in the bioimpedance when the blood is pumped out by the heartbeat. Stroke volume can be calculated from the values. Moreover, the cardiac output can be calculated by multiplying the calculated stroke volume by the heart rate. The bioimpedance calculation means 66 has a bandpass filter having frequency characteristics in a frequency band corresponding to the heartbeat, for example, 0.5 Hz to 2 Hz, with respect to the signal sent to the cardiac output acquisition means 68. good too. As a result, noise signals other than signals corresponding to heartbeats can be reduced from the bioimpedance calculated by the bioimpedance calculator 66, and cardiac output information with less error can be obtained.

Next, with reference to FIGS. 3 to 7, experimental results of simultaneous measurement of biopotential and bioimpedance performed using the smartwear 1 according to the present embodiment are shown below as examples. The examples shown below are merely illustrative examples, and the present invention is not limited to the following examples.

The smart wear 1 according to the present embodiment uses a stretchable shirt that is in close contact with the wearer's upper body on the clothes 2 to attach the first electrode 3 and wiring 31, the second electrode 4 and wiring 41, the ground electrode 5 and The wiring 51 was integrally formed using COCOMI (registered trademark) as a material, and fixed to the back side of the garment 2 by thermocompression bonding. The measurement device 6 includes the functions of a measurement unit 60, a control unit 71, a storage unit 72, and a communication unit 73, which are configured on a substrate and accommodated in one housing. 6 is attached to the clothing 2, it is configured to be connected to the wiring 31, the wiring 41 and the wiring 51. - 特許庁

FIG. 3 shows a circuit diagram of an oscillation circuit used in the current applying means 61 of the measuring device 6 according to this embodiment. In FIG. 3, R1, R2, R3, R4 and R5 are resistors, VR1 and VR2 are variable resistors, C1 and C2 are capacitors, OP1, OP2, OP3 and OP4 are operational amplifiers, and GND is ground. The first electrode 3 and the second electrode 4 are connected to the two terminals provided on the current applying means 61, and the electric signal generated by the current applying means 61 is applied to the first electrode 3 and the second electrode 4. configured to do so. The resistance value, capacitance, and the like of each component of the current applying means 61 were appropriately set so that a constant current with a predetermined frequency was applied to the first electrode 3 and the second electrode 4 .

FIG. 4 shows a circuit diagram of circuits used for the potential difference measuring means 62, the first frequency filter 63 and the second frequency filter 66 of the measuring device 6 according to this embodiment. In FIG. 4, R11, R12, R21, R22, R31, R32, R41, R42, R51, R61, R62, R63, R64, R65, R71, R81 and R82 are resistors, C11, C12, C21, C22, C41, C42, C51 and C71 are capacitors, D61 and D62 are diodes, OP11, OP21, OP31, OP41, OP51, OP61, OP62 and OP81 are operational amplifiers, AMP is an instrumentation amplifier, and GND is ground.

The potential difference measuring means 62 has an instrumentation amplifier AMP, and the first electrode 3 is connected to the Vin+ terminal of the instrumentation amplifier AMP, and the second electrode 4 is connected to the Vin- terminal thereof. A ground electrode 5 was connected to the B-GND terminal. The B-GND terminal is connected to the ground GND in the circuit of FIG. 4, and the potential of the ground electrode 5 is used as the reference potential of the ground GND. The electrical signal input from the first electrode 3 and the second electrode 4 to the potential difference measuring means 62 is amplified as an electrical signal indicating the potential difference between the first electrode 3 and the second electrode 4 by the potential difference measuring means 62, and the It is configured to be output in parallel to the first frequency filter 63 and the second frequency filter 64 .

The first frequency filter 63 is composed of a bandpass filter 631 , a Sallen-Key secondary lowpass filter 632 and an inverting amplifier circuit 633 . Bandpass filter 631 was configured to pass signals with frequencies between 10 Hz and 1000 Hz using resistors R11 and R12, capacitors C11 and C12, and operational amplifier OP11. The resistance values of the resistors were 1.6 kΩ for R11 and 1.6 kΩ for R12, and the capacitance of the capacitors was 10 μF for C11 and 0.1 μF for C12. A secondary low-pass filter 632 is configured to pass signals with frequencies below 1000 Hz using resistors R21 and R22, capacitors C21 and C22, and operational amplifier OP21. The resistance values of the resistors were 1.6 kΩ for R21 and 1.6 kΩ for R22, and the capacitance of the capacitors was 0.1 μF for C21 and 0.1 μF for C22. The inverting amplifier circuit 633 is configured to amplify the electrical signal that has passed through the secondary low-pass filter 632 using a resistor R31, a resistor R32, and an operational amplifier OP31. As for the resistance values of the resistors, R31 is 100Ω and R32 is 51 kΩ.

The electric signal inputted from the potential difference measuring means 62 to the first frequency filter 63 passes through the bandpass filter 631, the secondary lowpass filter 632 and the inverting amplifier circuit 633 in order, and is outputted from the Vout (ECG) terminal. An electrocardiogram acquisition means 65 is connected to the Vout (ECG) terminal, and the electrocardiogram acquisition means 65 acquires an electrocardiogram based on the electrical signal input from the first frequency filter 63 via the Vout (ECG) terminal. Configured. In this embodiment, the pass band of the bandpass filter 631 is set to 10-1000 Hz, and the cutoff frequency of the secondary low-pass filter 632 is set to 1000 Hz to widen the band. It can be a band.

The second frequency filter 64 comprises a Sallen-Key secondary high-pass filter 641 , a primary low-pass filter 642 , a full-wave rectifier circuit 643 , a primary low-pass filter 644 and a non-inverting amplifier circuit 645 . A second-order high-pass filter 641 is configured to pass signals of frequencies above 885 Hz using capacitors C41 and C42, resistors R41 and R42, and operational amplifier OP41. The capacitance of the capacitors was 0.1 μF for C41 and 0.1 μF for C42, and the resistance values of the resistors were 1.8 kΩ for R41 and 1.8 kΩ for R42. The primary low-pass filter 642 is configured to pass signals of 200 kHz or less using a resistor R51, a capacitor C51 and an operational amplifier OP51. The resistance value of the resistor R51 is 82Ω, and the capacitance of the capacitor C51 is 0.01 μF. The full-wave rectifier circuit 643 uses resistors R61, R62, R63, R64 and R65, diodes D61 and D62, and operational amplifiers OP61 and OP62 to obtain the absolute value of the signal output from the primary low-pass filter 642. Configured. The resistance values of the resistors were 17 kΩ for R61, 17 kΩ for R62, 17 kΩ for R63, 33 kΩ for R64, and 33 kΩ for R65. The primary low-pass filter 644 is configured to pass signals below 10 Hz using a resistor R71 and a capacitor C71. The resistance value of the resistor R71 was set to 160 kΩ, and the capacitance of the capacitor C71 was set to 0.1 μF. The non-inverting amplifier circuit 645 is configured to amplify the electrical signal input from the primary low-pass filter 644 using resistors R81, R82 and operational amplifier OP81. As for the resistance values of the resistors, R81 was set to 200Ω, and R82 was set to 2 kΩ.

The electric signal input from the potential difference measuring means 62 to the second frequency filter 64 passes through a secondary high-pass filter 641, a primary low-pass filter 642, a full-wave rectifier circuit 643, a primary low-pass filter 644 and a non-inverting amplifier circuit 645 in order. and output from the Vout (Z) terminal. A bioimpedance calculator 66 is connected to the Vout (Z) terminal, and the bioimpedance calculator 66 calculates the bioimpedance based on the electrical signal input from the second frequency filter 64 via the Vout (Z) terminal. configured to The respiration acquisition means 67 and the cardiac output acquisition means 68 are configured to acquire respiration information and cardiac output information, respectively, based on the bio-impedance calculated by the bio-impedance calculation means 66 . In addition, at the output stage from the primary low-pass filter 642 of the second frequency filter 64, the impedance value corresponding to the respiratory information and the cardiac output information is output as the amplitude of the sine wave, and at this stage the sine wave is accurately reproduced. , and the amplitude may be calculated. However, when trying to acquire a sine wave waveform by A/D conversion, the sampling frequency must be several times the frequency of the sine wave. The frequency of the sine wave corresponds to the frequency of the current for measurement by the current applying means 61, and requires a high sampling frequency, resulting in high power consumption. In order to avoid this, in this embodiment, a full-wave rectifier circuit 643 and a primary low-pass filter 644 are provided. By integrating (integrating), the waveform is converted into a waveform corresponding to the amplitude change, and the amplitude information can be obtained even at a low sampling frequency.

In FIG. 5, a plurality of known resistances from 100 Ω to 10 kΩ are connected between the first electrode 3 and the second electrode 4 of the smart wear 1 according to this embodiment having the above configuration, and the current applying means 61 is used to generate a current for measurement. The results of measuring the potential difference between the first electrode 3 and the second electrode 4 by applying constant currents of 25 kHz and 50 kHz are shown. FIG. 5A is a diagram plotting the resistance value against the potential difference measured when the frequency of the current for measurement is 25 kHz, and FIG. It is the figure which plotted the resistance value. As shown in FIG. 5(a), when the frequency of the current for measurement was 25 kHz, the measured potential difference and the resistance value exhibited linearity up to 6.8 kΩ, which was well fitted to the regression line obtained by regression analysis. It is understood that Moreover, as shown in FIG. 5(b), when the frequency of the current for measurement is 50 kHz, the measured potential difference and the resistance value show linearity up to 820 Ω, and are well fitted to the regression line obtained by the regression analysis. It is understood that Thus, in both cases where the frequency of the measurement current is 25 kHz and 50 kHz, as the resistance value, that is, the impedance increases, the measured potential difference increases. Assuming that the potential difference is V and the impedance is Z, the relationship V=ZI is established, and it can be seen that the bioimpedance can be calculated by the smartwear 1 from the current for measurement and the potential difference for calculation.

6 and 7 show the results of simultaneous measurement of biopotential and bioimpedance when a wearer wears the smartwear 1 according to the present embodiment having the above configuration. Here, the first electrode 3 and the second electrode 4 are in contact with the left side of the center and the right side of the center of the chest front of the wearer, respectively, and the current for measurement by the current applying means 61 is a constant current of 25 kHz. set to In addition, the wearer performed the measurement by repeating three breathing actions of stopping breathing, inhaling, and exhaling in order every 5 seconds.

In FIG. 6, the waveform of the electrocardiogram obtained by the electrocardiogram obtaining means 65 is indicated by a solid line, and the waveform of the bio-impedance obtained by the respiration obtaining means 67 is indicated by a broken line. In the electrocardiogram acquiring means 65, the biopotential signal passed through the first frequency filter 63 is passed through a band-pass filter with a passband of 10 Hz to 1000 Hz to acquire an electrocardiogram. The respiration acquisition means 67 acquires respiration information based on the bioimpedance calculated by the bioimpedance calculation means 66 by passing the bioimpedance signal passed through the second frequency filter 64 through a bandpass filter with a passband of 0.01 Hz to 2 Hz. . In FIG. 6, the bioimpedance waveform obtained by the respiration acquisition means 67 is indicated by the voltage value after passing through the 0.01 Hz-2 Hz band-pass filter by the bioimpedance calculation means 66 and before the unit is converted to Ω. From FIG. 6, it can be seen that the smartwear 1 can measure the biopotential and acquire an electrocardiogram. In addition, it can be seen that the characteristic R wave in the electrocardiogram can also be acquired, and the heart rate and the like can be calculated from the acquired electrocardiogram. In addition, the waveform of the bioimpedance in FIG. 6 is almost flat when the wearer holds his breath, rises when he inhales, and decreases when he exhales. , it can be seen that the smartwear 1 can measure the bioimpedance and obtain the respiratory information.

In FIG. 7, the waveform of the electrocardiogram obtained by the electrocardiogram obtaining means 65 is indicated by a solid line, and the waveform of the bioimpedance obtained by the cardiac output obtaining means 68 is indicated by a broken line. In the electrocardiogram acquiring means 65, the biopotential signal passed through the first frequency filter 63 is passed through a band-pass filter with a passband of 10 Hz to 1000 Hz to acquire an electrocardiogram. Cardiac output acquisition means 68 obtains heartbeat information based on bioimpedance calculated by bioimpedance calculation means 66, which passes the bioimpedance signal that has passed through second frequency filter 64 through a bandpass filter with a passband of 0.5 Hz to 2 Hz. obtained. In FIG. 7, the bioimpedance waveform obtained by the cardiac output acquisition means 68 is indicated by the voltage value after passing through the 0.5 Hz-2 Hz bandpass filter in the bioimpedance calculation means 66 and before the unit is converted to Ω. rice field. The bioimpedance waveform obtained by the cardiac output acquisition means 68 in FIG. 7 is obtained by removing the frequency component of the change in bioimpedance due to respiration from the bioimpedance waveform obtained by the respiration acquisition means 67 in FIG. there is The bioimpedance waveform in FIG. 7 rises and falls periodically along with the waveform of the electrocardiogram. It can be seen that the change in bioimpedance accompanies the blood being pumped out by the pulsation of . Therefore, it can be seen that the smart wear 1 can acquire cardiac output information.

As described above, according to the smartwear 1 according to the present embodiment, the two electrodes, the first electrode 3 and the second electrode 4, can simultaneously measure the wearer's biopotential and bioimpedance. The number of electrodes of the smartwear 1 can be two, the first electrode 3 and the second electrode 4, or three at the most when the ground electrode 5 is used. It is possible to prevent the wearer from feeling uncomfortable due to an increase in the number of electrodes. The first electrode 3 and the second electrode 4 are fixed to the clothes 2 so as to be in contact with the wearer's chest. It is possible to simultaneously acquire biological information about a plurality of circulatory organs. Therefore, just by wearing the smartwear 1, the wearer can easily measure multiple pieces of biological information simultaneously over a long period of time. The information can be used to make multiple assessments.

Since the above is merely illustrative of the embodiments of the present invention, the scope of the present invention is not limited to the above embodiments, and can be changed as appropriate without departing from the spirit of the present invention. .

1 smart wear 2 clothes 3 first electrode 4 second electrode 5 ground electrode 6 measuring device 61 current applying means 62 potential difference measuring means 63 first frequency filter 64 second frequency filter 65 electrocardiogram acquisition means 66 biological impedance calculation means 67 respiration acquisition means 68 cardiac output acquisition means

Claims (6)

clothing worn by the wearer; and
a first electrode and a second electrode provided on the clothing so as to abut on the wearer's body when the clothing is worn;
current applying means for applying a measurement current between the first electrode and the second electrode for measuring bioimpedance;
Potential difference measuring means for measuring the inter-electrode potential difference between the first electrode and the second electrode while the measuring current is applied between the first electrode and the second electrode by the current applying means;
a first frequency filter for extracting a frequency component corresponding to a biopotential from the inter-electrode potential difference measured by the potential difference measuring means;
a second frequency filter for extracting, from the inter-electrode potential difference measured by the potential difference measuring means, a frequency component corresponding to the potential difference for calculation used to calculate the bioimpedance generated by the application of the current for measurement;
bioimpedance calculation means for calculating the bioimpedance based on the potential difference for calculation extracted by the second frequency filter;
The first frequency filter includes a band-pass filter that passes signals with a frequency of 10 Hz to 1000 Hz, a secondary low-pass filter that passes signals with a frequency of 1000 Hz or less, and an inversion that amplifies the electrical signal that has passed through the secondary low-pass filter. and an amplifier circuit,
The electric signal input from the potential difference measuring means to the first frequency filter passes through the hand-pass filter, the secondary low-pass filter, and the inverting amplifier circuit in order,
The second frequency filter includes a secondary high-pass filter, a primary low-pass filter (642) that passes signals of 200 kHz or less, and a full-wave filter that acquires the absolute value of the signal output from the primary low-pass filter (642). a rectifier circuit, a primary low-pass filter (644) that passes signals of 10 Hz or less, and a non-inverting amplifier circuit that amplifies the electrical signal input from the primary low-pass filter (644),
The electric signal input from the potential difference measuring means to the second frequency filter is composed of the secondary high-pass filter, the primary low-pass filter (642) that passes the signal of 200 kHz or less , the full-wave rectifier circuit, and the 10 Hz or less . and the non- inverting amplifier circuit in order. The clothes are clothes worn on the upper body of the wearer,
The first electrode is in contact with any position within a region surrounded by the center line of the front rib of the wearer's body, the left anterior axillary line, the upper end of the fifth rib, and the lower end of the eighth rib. provided on the garment,
The second electrode is positioned at any position within a region bounded by the center line of the ribs on the front surface of the wearer's body, the right anterior axillary line, the upper end of the fifth rib, and the lower end of the eighth rib. The smart wear according to claim 1, wherein the smart wear is provided on the garment so as to abut. 3. The smart wear according to claim 2, further comprising a breathing acquisition unit that acquires the wearer's breathing information based on the bioelectrical impedance calculated by the bioelectrical impedance calculation unit. 4. The smart device according to claim 2, further comprising cardiac output acquisition means for acquiring cardiac output information of the wearer based on the bioimpedance calculated by the bioimpedance calculation means. Wear. The smart wear according to any one of claims 2 to 4, further comprising electrocardiogram acquisition means for acquiring an electrocardiogram of the wearer based on the biopotential extracted by the first frequency filter. 6. The smart wear according to any one of claims 1 to 5, further comprising a ground electrode provided on the clothes so as to come into contact with the wearer's body when the clothes are worn.

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