WO2015156174A1 - センサ装置 - Google Patents
センサ装置 Download PDFInfo
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- WO2015156174A1 WO2015156174A1 PCT/JP2015/060149 JP2015060149W WO2015156174A1 WO 2015156174 A1 WO2015156174 A1 WO 2015156174A1 JP 2015060149 W JP2015060149 W JP 2015060149W WO 2015156174 A1 WO2015156174 A1 WO 2015156174A1
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- electrode layer
- dielectric layer
- sensor element
- living body
- capacitance
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
- A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
- A61B5/1126—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb using a particular sensing technique
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
- A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/024—Detecting, measuring or recording pulse rate or heart rate
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
- A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
- A61B5/113—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb occurring during breathing
- A61B5/1135—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb occurring during breathing by monitoring thoracic expansion
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
- A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
- A61B5/6813—Specially adapted to be attached to a specific body part
- A61B5/6814—Head
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
- A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
- A61B5/6813—Specially adapted to be attached to a specific body part
- A61B5/6823—Trunk, e.g., chest, back, abdomen, hip
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
- A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
- A61B5/6813—Specially adapted to be attached to a specific body part
- A61B5/6824—Arm or wrist
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
- A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
- A61B5/6813—Specially adapted to be attached to a specific body part
- A61B5/6828—Leg
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
- G01B7/22—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in capacitance
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
- G01L9/0072—Transmitting or indicating the displacement of flexible diaphragms using variations in capacitance
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2503/00—Evaluating a particular growth phase or type of persons or animals
- A61B2503/10—Athletes
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2505/00—Evaluating, monitoring or diagnosing in the context of a particular type of medical care
- A61B2505/09—Rehabilitation or training
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/02—Details of sensors specially adapted for in-vivo measurements
- A61B2562/0261—Strain gauges
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/12—Manufacturing methods specially adapted for producing sensors for in-vivo measurements
Definitions
- the present invention relates to a sensor device.
- the momentum of patients with motor paralysis such as paralysis and hemiplegia, measurement of the amount and range of movement of joints, etc., the heart rate of patients during training and rest, Respiration rate is measured on a daily basis.
- monitoring of the heart rate and respiratory rate of patients and elderly people who need care is routinely performed.
- Patent Document 2 discloses a pair of conductive cloths having elasticity on both surfaces of a sheet-like dielectric material that can be elastically deformed in all directions. There has been proposed a method using a capacitance-type pressure sensor that is arranged and configured.
- Patent Document 2 since the method described in Patent Document 2 monitors the heart rate and the respiratory rate by placing a capacitive pressure sensor under the sleeping human body, it is not possible to move the body during rehabilitation training. Measurement was difficult.
- the capacitive pressure sensor is a sensor that measures changes in capacitance due to deformation in the thickness direction of the dielectric layer, it is difficult to measure deformation in the surface direction of the dielectric layer in the first place. It was not possible to measure the state of movement.
- the present invention has created a capacitive sensor device capable of tracking the deformation of a living body surface with a completely different technical idea.
- the sensor device of the present invention comprises a sheet-like first dielectric layer made of an elastomer composition and a conductive composition containing carbon nanotubes, and the first dielectric layer is formed on each of the front and back surfaces of the first dielectric layer.
- a first electrode layer and a second electrode layer that are formed so that at least a part of the first electrode layer and the second electrode layer are opposed to each other, and a portion where the first electrode layer and the second electrode layer are opposed to each other serves as a detection unit.
- a sensor element that reversibly deforms so that the area of the front and back surfaces of the layer changes;
- a measuring instrument for measuring a change in capacitance in the detection unit It is used by being attached to a living body and used for tracking deformation of the living body surface.
- the sensor element is directly attached to the surface of the living body, and the life activity information and / or the movement information of the living body are measured based on the deformation of the living body surface.
- the sensor element is attached to the surface of the living body via a covering material, and based on the deformation of the living body surface, out of life activity information, living body exercise information, and deformation information of the covering material It is also preferable to measure at least one of the above.
- the sensor element further includes a second dielectric layer and a third electrode layer, and the second dielectric layer is on the front side of the first dielectric layer, and the surface of the first dielectric layer.
- the third dielectric layer is laminated so as to cover the first electrode layer formed on the first dielectric layer, and the third dielectric layer is disposed on the second dielectric layer so that at least a part of the third dielectric layer is opposed to the first dielectric layer. It is preferable that it is formed on the surface.
- the sensor device of the present invention further includes a storage unit that stores changes in the measured capacitance.
- the measuring instrument is a measuring instrument that measures a change in capacitance using a Schmitt trigger oscillation circuit, and the sensor element is attached so that the back side is close to a living body
- the second electrode layer formed on the back surface of the first dielectric layer is preferably connected to the GND side of the measuring instrument.
- the measuring instrument is a measuring instrument that measures a change in capacitance using an inverting amplifier circuit, a half-wave voltage doubler rectifier circuit, or an automatic balanced bridge circuit. It is also preferable that the second electrode layer attached so as to be close to a living body and formed on the back surface of the first dielectric layer is connected to the side of the measuring instrument that generates an AC signal.
- the sensor device of the present invention includes a dielectric layer made of an elastomer composition and a conductive layer made of a conductive composition containing carbon nanotubes, and a sensor element that reversibly deforms so that the area of the front and back surfaces of the dielectric layer changes. Is attached to the living body to track the deformation of the living body surface. Therefore, even when the surface of the living body is greatly deformed, various information corresponding to the deformation of the surface of the living body can be easily and reliably measured. Further, the sensor device of the present invention can be easily downsized due to its configuration, and can be easily carried by downsizing.
- FIG. 1 It is the schematic which shows an example of the sensor apparatus of this invention.
- A is a perspective view schematically showing an example of a sensor element constituting the sensor device of the present invention, and (b) is a cross-sectional view taken along line AA of (a).
- A) is a perspective view schematically showing another example of a sensor element constituting the sensor device of the present invention, and (b) is a sectional view taken along the line BB of (a).
- A)-(d) is a perspective view for demonstrating the manufacturing process of the sensor element in an Example.
- FIG. (A) is a schematic diagram which shows the attachment part of the sensor element in Example 1
- (b) is a graph which shows the change of the electrostatic capacitance measured in Example 1.
- FIG. (A) is a schematic diagram which shows the attachment part of the sensor element in Example 2
- (b) is a graph which shows the change of the electrostatic capacitance measured in Example 2.
- FIG. (A) is a schematic diagram which shows the attachment part of the sensor element in Example 3
- (b) is a graph which shows the change of the electrostatic capacitance measured in Example 3.
- FIG. (A) is a schematic diagram which shows the attachment part of the sensor element in Example 4
- (b) is a graph which shows the change of the electrostatic capacitance measured in Example 4.
- FIG. 10 is a schematic diagram illustrating an inverting amplifier circuit used for capacitance measurement in Example 6.
- FIG. 10 is a schematic diagram illustrating a Schmitt trigger oscillation circuit used for capacitance measurement in Example 7.
- FIG. 10 is a schematic diagram showing a half-wave voltage doubler rectifier circuit used for capacitance measurement in Example 8.
- the sensor device of the present invention includes a sensor element and a measuring instrument, is used by being attached to a living body, and is used for tracking deformation of the living body surface.
- the sensor element includes a sheet-shaped first dielectric layer made of an elastomer composition and a conductive composition containing carbon nanotubes, and the first dielectric layer is sandwiched between the front surface and the back surface of the first dielectric layer.
- the first electrode layer and the second electrode layer are formed so that at least a part thereof is opposed to each other, the opposed portions of the first electrode layer and the second electrode layer are used as a detection unit, and the first dielectric layer It deforms reversibly so that the area of the front and back surfaces changes.
- the measuring instrument measures a change in capacitance in the detection unit.
- FIG. 1 is a schematic view showing an example of the sensor device of the present invention.
- FIG. 2A is a perspective view schematically showing an example of a sensor element constituting the sensor device of the present invention
- FIG. 2B is a sectional view taken along line AA in FIG.
- the sensor device 1 includes a sensor element 2 that detects capacitance, a measuring instrument 3 that is electrically connected to the sensor element 2, and a measurement result obtained by the measuring instrument 3.
- the display 4 for displaying is provided.
- the measuring instrument 3 includes a Schmitt trigger oscillation circuit 3a for converting the capacitance C into a frequency signal F, an F / V conversion circuit 3b for converting the frequency signal F into a voltage signal V, and a power supply circuit (not shown). .
- the measuring instrument 3 converts the capacitance C detected by the detection unit of the sensor element 2 into a frequency signal F, further converts it into a voltage signal V, and transmits it to the display 4.
- the display 4 includes a monitor 4a, an arithmetic circuit 4b, and a storage unit 4c.
- the display 4 displays the change in the capacitance C measured by the measuring instrument 3 on the monitor 4a and stores the change in the capacitance C as recording data.
- the sensor element 2 includes a sheet-like dielectric layer 11 made of an elastomer composition, and a front electrode layer formed on the surface (front surface) of the dielectric layer 11.
- the front side protective layer 15 ⁇ / b> A and the back side protective layer 15 ⁇ / b> B laminated on each other and the adhesive layer 18 laminated on the back side protective layer 15 ⁇ / b> B are provided.
- the front-side electrode layer 12A and the back-side electrode layer 12B have the same plan view shape, and the front-side electrode layer 12A and the back-side electrode layer 12B face each other across the dielectric layer 11.
- a portion where the front side electrode layer 12A and the back side electrode layer 12B face each other serves as a detection unit.
- the front-side electrode layer and the back-side electrode layer included in the sensor element do not necessarily have to face each other across the dielectric layer, and at least a part thereof may be opposed.
- the dielectric layer 11 corresponds to the first dielectric layer
- the front electrode layer 12A corresponds to the first electrode layer
- the back electrode layer 12B corresponds to the second electrode layer.
- the sensor element 2 can be deformed (stretched) in the surface direction.
- the front electrode layer 12 ⁇ / b> A and the back electrode layer 12 ⁇ / b> B, and the front protective layer 15 ⁇ / b> A and the back protective layer 15 ⁇ / b> B (hereinafter, both are combined) Simply referred to as a protective layer).
- the capacitance of the detection unit changes in correlation with the deformation amount of the dielectric layer 11 as the sensor element 2 is deformed. Therefore, the deformation amount of the sensor element 2 can be detected by detecting the change in capacitance.
- the sensor device of the present invention is used to track the deformation of the surface of a living body, and is used by attaching the sensor element to a living body.
- the sensor element may be directly affixed to the surface of the living body, or may be indirectly affixed to the surface of the living body via a covering material that covers the surface of the living body such as clothes, supporters, and bandages.
- the sensor device of the present invention when the capacitance of the detection unit is measured in a state where the sensor element is attached to a living body, the value of the capacitance of the detection unit changes according to the deformation of the surface of the living body. Therefore, the deformation of the living body surface can be tracked based on the change in the capacitance, and various information can be acquired from the tracking result.
- usage modes of the sensor device will be described.
- the sensor device of the present invention can be used by directly attaching the sensor element to the surface of a living body such as skin.
- the capacitance of the detection unit changes according to the deformation amount of the living body surface. Become. Therefore, the deformation amount of the living body surface can be measured by measuring the capacitance of the detection unit. Then, by measuring the amount of deformation of the living body surface, it is possible to acquire life activity information and living body motion information correlated with the deformation of the living body surface.
- the sensor device of the present invention can measure, for example, a pulse rate (heart rate), a respiration rate, and a respiration size as the life activity information.
- a pulse rate heart rate
- a respiration rate respiration rate
- a respiration size as the life activity information.
- the movement information of the living body that can be acquired by the sensor device is not particularly limited, and the movement state can be measured as long as the movement of the living body surface expands and contracts due to muscle contraction during the movement.
- Examples of the movement information of the living body include, for example, the amount of bending (bending angle) when the joint is bent, the movement of the cheek during pronunciation / speaking, the movement of the facial muscles, the movement of the scapula, the movement of the gluteal muscles, Movement, bending of waist, swelling of chest, size of thigh and calf contraction due to muscle contraction, movement of throat when swallowing, movement of legs, movement of hands, movement of fingers, movement of soles, blinking Examples include movement, easiness of skin elongation (flexibility), and the like.
- the sensor element When measuring the pulse rate (heart rate) with the above sensor device, the sensor element is affixed to the place where the pulse on the living body touches (for example, radial artery or carotid artery), and the capacitance is measured for a predetermined time.
- the heart rate can be acquired by continuing. This is because the skin expands and contracts in accordance with the pulse, and the number of expansion and contraction becomes the pulse rate.
- the heart rate can be acquired by sticking the sensor element to the chest of the living body and continuously measuring the capacitance for a predetermined time. This is because the skin of the chest expands and contracts with breathing, and the number of stretches coincides with the breathing rate.
- the sensor element When measuring the bending amount of a joint with the sensor device, the sensor element is attached to a measurement target part (measurement target joint), and the capacitance of the measurement target part is measured by moving the measurement target part.
- the amount of bending can be acquired. This is because the skin of the portion expands and contracts in accordance with the movement of the measurement target region, and the bending amount of the measurement target region can be calculated from the expansion and contraction amount.
- the sensor element is attached to the periphery (cheek etc.) around the mouth, and while speaking in that state (or trying to speak even in a state where speaking cannot actually be performed), the capacitance is increased.
- the skin around the mouth is deformed according to the type of uttered sound, so that the capacitance changes in accordance with the deformation of the skin. Therefore, it is possible to obtain correlation information between the movement of the skin around the mouth at the time of utterance and the value of the capacitance and how to change the capacitance.
- the following training is possible.
- As training for facial muscles for example, by attaching sensor elements symmetrically, the movement of the skin can be measured quantitatively or visualized in real time.
- the sensor element is attached to the ankle or instep, and in that state, while performing exercises such as ⁇ stepping '', ⁇ jumping '', ⁇ standing on toes '', ⁇ resting '',
- exercises such as ⁇ stepping '', ⁇ jumping '', ⁇ standing on toes '', ⁇ resting ''.
- the capacitance is measured, the skin is deformed according to the movement of the foot, and the capacitance is changed according to the deformation of the skin. Therefore, it is possible to specify the movement of the foot based on the value of the capacitance and how it changes.
- the sensor element is affixed to the palm of the hand or back of the hand, and in that state, exercise such as "open hand”, “close hand”, “raise any finger”, “make a joke", etc.
- exercise such as "open hand”, “close hand”, “raise any finger”, “make a joke”, etc.
- the capacitance is measured while performing the process, the skin is deformed according to the movement of the hand, and the capacitance is changed according to the deformation of the skin. Therefore, it is possible to specify the movement of the hand based on the value of capacitance and the manner of change.
- various life activity information and biological motion information can be measured by using the sensor element attached to the surface of the living body such as skin.
- the relationship between the type of motion and the capacitance value and how to change it as calibration information for each living body to be measured It is preferable to obtain it. This is because even if there is an individual difference, it can be measured more accurately.
- the sensor device of the present invention can also be used by attaching the sensor element to a living body surface through a covering material.
- the covering material include clothing, supporters, bandages, taping tapes, and the like.
- the clothing is preferably of the type that is in close contact with the skin when worn, and specific examples include training underwear and swimwear.
- the life activity information and the movement of the living body are the same as when the sensor element is directly attached to the surface of the living body. Information can be acquired.
- the sensor element when the sensor element is used by being attached to the surface of a living body via a covering material, deformation information of the covering material can be measured.
- deformation information of the covering material can be measured.
- the fabric of the training underwear is stretched or returned to the original state following the movement of the body. Deform. Therefore, the capacitance changes according to the deformation (expansion / contraction) of the fabric. Therefore, it is possible to measure the deformation of the training underwear (coating material) based on the value of capacitance and how it changes.
- the sensor element is attached to the surface of a living body via a covering material, and thus, not only life activity information and living body motion information but also deformation information of the covering material is acquired. Can do.
- the sensor device of the present invention may include a plurality of sensor elements.
- the sensor device may acquire the same type of information at different locations at the same time, or may acquire different types of information at the same time.
- the sensor device includes two or more sensor elements, for example, the sensor elements are attached to the body symmetrically (for example, right and left insteps) and stepping is performed in that state.
- the sensor elements are attached to the body symmetrically (for example, right and left insteps) and stepping is performed in that state.
- the sensor elements are attached to the body symmetrically (for example, right and left insteps) and stepping is performed in that state.
- the sensor elements are attached to the body symmetrically (for example, right and left insteps) and stepping is performed in that state.
- the sensor elements are attached to the body symmetrically (for example, right and left insteps) and stepping is performed in that state.
- the sensor elements are attached to the body symmetrically (for example, right and left insteps) and stepping
- the sensor element may include a second dielectric layer and a third electrode layer in addition to the first dielectric layer and the first electrode layer and the second electrode layer formed on both surfaces thereof.
- FIG. 3A is a perspective view schematically showing another example of the sensor element constituting the sensor device of the present invention
- FIG. 3B is a sectional view taken along line BB in FIG.
- a sensor element 2 ′ shown in FIGS. 3A and 3B includes a sheet-like first dielectric layer 41A made of an elastomer composition and a first dielectric layer 41A formed on the surface (front surface) of the first dielectric layer 41A.
- the sensor element 2 'includes a first wiring 43A connected to the first electrode layer 42A, a second wiring 43B connected to the second electrode layer 42B, and a third wiring connected to the third electrode layer 42C. 43C, the first connection portion 44A attached to the end of the first wiring 43A opposite to the first electrode layer 42A, and the end of the second wiring 43B attached to the end opposite to the second electrode layer 42B.
- a second connection portion 44B and a third connection portion 44C attached to the end of the third wiring 43C opposite to the third electrode layer 42C are provided.
- a back side protective layer 45B and a front side protective layer 45A are provided on the back side of the first dielectric layer 41A and the front side of the second dielectric layer 41B, respectively.
- the first electrode layer 42A to the third electrode layer 42C have the same planar view shape. Further, the first electrode layer 42A and the second electrode layer 42B are opposed to each other across the first dielectric layer 41A, and the first electrode layer 42A and the third electrode layer 42C sandwich the second dielectric layer 41B. The whole is facing. In the sensor element 2 ′, a portion where the first electrode layer 42A and the second electrode layer 42B face each other and a portion where the first electrode layer 42A and the third electrode layer 42C face each other serve as a detection unit.
- the sensor element 2 ′ may include an adhesive layer in the same manner as the sensor element 2 shown in FIG.
- the sensor device of the present invention is a sensor device that uses a sensor element attached to a living body and tracks the deformation of the surface of the living body.
- the sensor element is attached to a living body, since the living body surface is a conductor, not only when the living body surface is in direct contact with the electrode layer, but also when it is in contact with the protective layer, it is in contact with or close to the living body.
- the noise itself causes noise.
- the first electrode layer and the second electrode layer By appropriately connecting the first electrode layer and the second electrode layer to the measuring instrument, it is possible to eliminate measurement errors due to noise and accurately measure the change in capacitance. Further, in the sensor element having the second dielectric layer and the third electrode layer in addition to the first dielectric layer, the first electrode layer, and the second electrode layer as shown in FIG. Or measurement errors due to noise from both sides can be eliminated. As a result, life activity information, living body motion information, and deformation information of the covering material can be measured more accurately. In addition, the connection method of a sensor element and a measuring device is mentioned later.
- Dielectric layer (first dielectric layer and second dielectric layer)
- the dielectric layer is a sheet-like material made of an elastomer composition, and can be reversibly deformed so that the areas of the front and back surfaces thereof are changed.
- the front and back surfaces of the sheet-like dielectric layer mean the front and back surfaces of the dielectric layer.
- elastomer composition what contains an elastomer and another arbitrary component as needed is mentioned.
- the elastomer examples include natural rubber, isoprene rubber, nitrile rubber (NBR), ethylene propylene rubber (EPDM), styrene / butadiene rubber (SBR), butadiene rubber (BR), chloroprene rubber (CR), silicone rubber, and fluorine.
- examples thereof include rubber, acrylic rubber, hydrogenated nitrile rubber, and urethane rubber. These may be used alone or in combination of two or more. Of these, urethane rubber and silicone rubber are preferable. This is because the permanent set (or permanent elongation) is small. Furthermore, urethane rubber is particularly preferable because it has excellent adhesion to carbon nanotubes compared to silicone rubber.
- the urethane rubber is formed by reacting at least a polyol component and an isocyanate component.
- the urethane rubber include, for example, an olefin urethane rubber having an olefin polyol as a polyol component, an ester urethane rubber having an ester polyol as a polyol component, an ether urethane rubber having an ether polyol as a polyol component, Examples thereof include a carbonate-based urethane rubber having a carbonate-based polyol as a polyol component, and a castor oil-based urethane rubber having a castor oil-based polyol as a polyol component. These may be used alone or in combination of two or more.
- the urethane rubber may be a combination of two or more polyol components.
- Examples of the olefin-based polyol include Epol (made by Idemitsu Kosan Co., Ltd.) and the like.
- Examples of the ester polyol include polylite 8651 (manufactured by DIC).
- Examples of the ether polyol include polyoxytetramethylene glycol, PTG-2000SN (Hodogaya Chemical Co., Ltd.), polypropylene glycol, Preminol S3003 (Asahi Glass Co., Ltd.), Pandex GCB-41 (DIC Corporation) and the like. Can be mentioned.
- isocyanate component A conventionally well-known isocyanate component can be used. Further, when the urethane rubber is synthesized, a chain extender, a crosslinking agent, a catalyst, a vulcanization accelerator and the like may be added to the reaction system as necessary.
- the elastomer composition may contain additives such as a plasticizer, an antioxidant, an antioxidant, a colorant, a dielectric filler, and the like.
- the average thickness of the dielectric layer is preferably 10 to 1000 ⁇ m from the viewpoint of improving the detection sensitivity by increasing the capacitance C and improving the followability to the measurement object. More preferably, it is 30 to 200 ⁇ m.
- the dielectric layer is preferably deformable so that the area of the front and back surfaces increases by 30% or more from the unstretched state.
- a dielectric layer having such characteristics is suitable for deformation following the deformation of the measurement object when used by being attached to the measurement object.
- being deformable so as to increase by 30% or more means that it does not break even when the load is increased and the area is increased by 30%, and when the load is released, it is restored to its original state (that is, It is in the range of elastic deformation.
- the deformable range so as to increase the area of the front and back surfaces of the dielectric layer is more preferably 50% or more, still more preferably 100% or more, and particularly preferably 200% or more. Note that the range in which the dielectric layer can be deformed in the plane direction can be controlled by the design (material, shape, etc.) of the dielectric layer.
- the relative dielectric constant of the dielectric layer at room temperature is preferably 2 or more, and more preferably 5 or more. If the relative dielectric constant of the dielectric layer is less than 2, the capacitance C becomes small, and there is a possibility that sufficient sensitivity as a sensor element cannot be obtained.
- the Young's modulus of the dielectric layer is preferably 0.1 to 10 MPa.
- the Young's modulus is less than 0.1 MPa, the dielectric layer is too soft, high quality processing is difficult, and sufficient measurement accuracy may not be obtained.
- the Young's modulus exceeds 10 MPa, the dielectric layer is too hard and there is a risk of inhibiting deformation of the living body surface.
- the hardness of the dielectric layer is 0 to 30 ° using a type A durometer according to JIS K 6253 (JIS A hardness), or a type C durometer according to JIS K 7321.
- the used hardness is preferably 10 to 55 °. If the dielectric layer is too soft, high quality processing is difficult, and sufficient measurement accuracy may not be ensured. On the other hand, if the dielectric layer is too hard, there is a risk of inhibiting deformation of the living body surface.
- the sensor element has the first dielectric layer and the second dielectric layer, they do not necessarily have to be composed of an elastomer composition having the same composition, but are composed of an elastomer composition having the same composition. It is preferable. This is because the same behavior is exhibited during expansion and contraction.
- Electrode layer (first electrode layer to third electrode layer)
- the electrode layers are made of a conductive composition containing carbon nanotubes.
- a known carbon nanotube can be used as the carbon nanotube.
- the carbon nanotube may be a single-walled carbon nanotube (SWNT), a double-walled carbon nanotube (DWNT), or a multi-walled carbon nanotube (MWNT) of three or more layers (in the present specification, both Together, they are simply referred to as multi-walled carbon nanotubes).
- SWNT single-walled carbon nanotube
- DWNT double-walled carbon nanotube
- MWNT multi-walled carbon nanotube
- two or more types of carbon nanotubes having different numbers of layers may be used in combination.
- each carbon nanotube is not particularly limited, and the purpose of use of the sensor device, the conductivity and durability required for the sensor element, and the formation of an electrode layer are also formed. Therefore, it is only necessary to make a comprehensive decision on the processing and cost for the selection.
- the average length of the carbon nanotube is preferably 10 ⁇ m or more, and more preferably 50 ⁇ m or more.
- An electrode layer formed using carbon nanotubes having such a long fiber length is excellent in electrical conductivity, and its electric resistance hardly increases when deformed following the deformation of the dielectric layer (particularly when stretched). Furthermore, this is because it has excellent characteristics that the variation in electric resistance is small even when it is repeatedly expanded and contracted.
- the electrical resistance may increase with the deformation of the electrode layer, or the variation in electrical resistance may increase when the electrode layer is repeatedly expanded and contracted. . In particular, such inconvenience is likely to occur when the amount of deformation of the sensor element (dielectric layer) increases.
- the preferable upper limit of the average length of the carbon nanotube is 1000 ⁇ m. Carbon nanotubes having an average length exceeding 1000 ⁇ m are difficult to manufacture and obtain at present. If the average length exceeds 1000 ⁇ m, as will be described later, when a carbon nanotube dispersion is applied to form an electrode layer, a conductive path is difficult to be formed due to insufficient dispersibility of the carbon nanotubes. As a result, there is a concern that the conductivity of the electrode layer becomes insufficient.
- the lower limit of the average length of the carbon nanotubes is more preferably 100 ⁇ m, and the upper limit is more preferably 600 ⁇ m.
- the average length of the carbon nanotubes is within the above range, the electrical conductivity is excellent, the electrical resistance hardly increases when stretched, and the variation in electrical resistance is small when repeatedly stretched. It can be surely secured.
- the fiber length of the carbon nanotube may be measured from an observation image obtained by observing the carbon nanotube with an electron microscope.
- the average length of the carbon nanotubes may be calculated based on, for example, the fiber lengths of 10 carbon nanotubes randomly selected from the observed image of the carbon nanotubes.
- the average fiber diameter of the carbon nanotube is not particularly limited, but is preferably 0.5 to 30 nm.
- the fiber diameter is less than 0.5 nm, the dispersion of the carbon nanotubes is deteriorated. As a result, the conductive path is not widened, and the conductivity of the electrode layer may be insufficient.
- the average fiber diameter of the carbon nanotube is more preferably 5 to 20 nm.
- multi-walled carbon nanotubes are preferable to single-walled carbon nanotubes.
- single-walled carbon nanotubes even when carbon nanotubes having an average length in the above-mentioned preferred range are used, the electrical resistance increases, the electrical resistance increases greatly during stretching, or the electrical resistance during repeated expansion and contraction. May vary widely. This is presumed as follows. That is, since single-walled carbon nanotubes are usually synthesized as a mixture of metallic carbon nanotubes and semiconducting carbon nanotubes, the presence of these semiconducting carbon nanotubes increases electrical resistance or increases electrical resistance when stretched. It is speculated that this is the cause of the increase or the electric resistance greatly varies during repeated expansion and contraction.
- the carbon nanotube is preferably a multi-walled carbon nanotube.
- the carbon nanotubes preferably have a carbon purity of 99% by weight or more.
- Carbon nanotubes may contain catalytic metals, dispersants, and the like in the production process.
- impurities components other than such carbon nanotubes are used, the decrease in conductivity or May cause variations in electrical resistance.
- the carbon nanotubes may be those produced by a conventionally known production method, and those produced by a substrate growth method are preferred.
- the substrate growth method is a kind of CVD method, and is a method for producing carbon nanotubes by growing a carbon catalyst by supplying a carbon source to a metal catalyst coated on the substrate.
- the substrate growth method is a production method suitable for producing carbon nanotubes having relatively long fiber lengths and uniform fiber lengths. Therefore, it is suitable as a method for producing carbon nanotubes used in the present invention.
- the fiber length of the carbon nanotube is substantially the same as the growth length of the CNT forest. Therefore, when the fiber length of the carbon nanotube is measured using an electron microscope, the growth length of the CNT forest may be measured.
- the conductive composition may contain, for example, a binder component in addition to the carbon nanotube.
- the binder component functions as a binder material, and by including the binder component, the adhesion between the electrode layer and the dielectric layer and the strength of the electrode layer itself can be improved. Furthermore, when the binder component is contained, since the scattering of the carbon nanotubes can be suppressed when the electrode layer is formed by the method described later, the safety at the time of forming the electrode layer can be improved.
- binder component examples include butyl rubber, ethylene propylene rubber, polyethylene, chlorosulfonated polyethylene, natural rubber, isoprene rubber, butadiene rubber, styrene / butadiene rubber, polystyrene, chloroprene rubber, nitrile rubber, polymethyl methacrylate, polyacetic acid.
- examples include vinyl, polyvinyl chloride, acrylic rubber, styrene-ethylene-butylene-styrene block copolymer (SEBS), and the like.
- SEBS styrene-ethylene-butylene-styrene block copolymer
- raw rubber in a state where natural rubber and synthetic rubber are not vulcanized
- the binder component is preferably the same type as the elastomer constituting the dielectric layer. This is because the adhesion between the dielectric layer and the electrode layer can be remarkably improved.
- the conductive composition may further contain various additives in addition to the carbon nanotube and the binder component.
- the additive include a dispersant for enhancing the dispersibility of carbon nanotubes, a crosslinking agent for a binder component, a vulcanization accelerator, a vulcanization aid, and an anti-aging agent, a plasticizer, and a softening agent. And coloring agents.
- the electrode layer may be formed substantially only from carbon nanotubes. Also in this case, sufficient adhesion with the dielectric layer can be ensured. In this case, the carbon nanotube and the dielectric layer are firmly adhered by van der Waals force or the like.
- the carbon nanotube content in the electrode layer is not particularly limited as long as it is a concentration at which conductivity is developed.
- the content of the carbon nanotube is preferably 0.1 to 100% by weight based on the total solid component of the electrode layer, although it varies depending on the kind of the binder component.
- the conductivity of the electrode layer can be improved. Therefore, the required conductivity can be ensured even if the electrode layer is thinned, and as a result, it is easier to make the electrode layer thin and to ensure the flexibility of the electrode layer.
- the average thickness of the electrode layer is preferably 0.1 to 10 ⁇ m.
- the electrode layer can exhibit better followability to the deformation of the dielectric layer.
- the average thickness is less than 0.1 ⁇ m, the conductivity is insufficient, and the measurement accuracy as a sensor element may be lowered.
- the average thickness exceeds 10 ⁇ m, the sensor element becomes hard due to the reinforcing effect of the carbon nanotubes, and the stretchability of the sensor element decreases. As a result, deformation of the living body surface may be hindered when the sensor element is attached to the living body surface directly or via a covering material.
- the “average thickness of the electrode layer” can be measured using, for example, a laser microscope (for example, VK-9510 manufactured by Keyence Corporation). Specifically, after scanning the thickness direction of the electrode layer formed on the surface of the dielectric layer in steps of 0.01 ⁇ m and measuring its 3D shape, the region where the electrode layer on the dielectric layer is laminated and the laminated layer In the non-applied area, the average height of each rectangular area of 200 ⁇ 200 ⁇ m is measured, and the step of the average height is set as the average thickness of the electrode layer.
- a laser microscope for example, VK-9510 manufactured by Keyence Corporation
- Each of the electrode layers (first electrode layer to third electrode layer) included in the sensor element does not necessarily need to be composed of a conductive composition having the same composition, but a conductive composition having the same composition. It is preferable that it is comprised from these.
- the first wiring (front wiring), the second wiring (back wiring), and the third wiring connected to the electrode layer are formed as necessary. It may be.
- Each of these wirings may be any wiring that does not hinder the deformation of the dielectric layer and can maintain conductivity even when the dielectric layer is deformed.
- what consists of an electroconductive composition similar to the said electrode layer is mentioned, for example.
- a first connecting portion (front side connection) for connecting to an external wiring as required, as in the example shown in FIGS. Part), a second connection part (back side connection part), and a third connection part may be formed.
- a first connecting portion (front side connection) for connecting to an external wiring as required as in the example shown in FIGS. Part
- a second connection part (back side connection part) for example.
- the sensor element may have a protective layer laminated on the outermost layer on the front side and / or the outermost layer on the back side as necessary.
- the protective layer By providing the protective layer, it is possible to electrically insulate between a portion (electrode layer or the like) having conductivity of the sensor element and a portion to which the sensor element is attached. Further, by providing the protective layer, the strength and durability of the sensor element can be increased, or the surface of the sensor element can be made non-sticky.
- the material of the said protective layer is not specifically limited, What is necessary is just to select suitably according to the required characteristic. Specific examples thereof include an elastomer composition similar to the material of the dielectric layer.
- the adhesion layer may be formed in the outermost layer of the back side of a sensor element like the example shown in FIG. Thereby, the said sensor element can be affixed on the biological body surface etc. via the adhesion layer.
- said adhesive layer For example, the layer which consists of an acrylic adhesive, a rubber adhesive, a silicone adhesive, etc. is mentioned.
- each pressure-sensitive adhesive may be a solvent type, an emulsion type, or a hot melt type.
- the pressure-sensitive adhesive may be appropriately selected and used according to the usage mode of the sensor device.
- the adhesive layer needs to have flexibility that does not hinder the expansion and contraction of the dielectric layer.
- the electrode at the second cycle of 100% stretched Change rate of electrical resistance of the electrode layer at 100% elongation at the 1000th cycle with respect to the electrical resistance of the layer ([1000th cycle, electrical resistance value at 100% elongation] ⁇ [second cycle, at 100% elongation)
- the absolute value of [electric resistance value]] / [electric resistance value at the second cycle, 100% elongation] ⁇ 100) is preferably small. Specifically, it is preferably 10% or less, and more preferably 5% or less.
- the reason why the electrical resistance of the electrode layer after the second cycle, not the first cycle, is to be evaluated is that the electrode at the time of extension at the first extension (first cycle) extended from the unextended state. This is because the behavior of the layer (how the electric resistance fluctuates) is greatly different from that during the second and subsequent expansion (second cycle). It is presumed that this is because the state of the carbon nanotube constituting the electrode layer is stabilized only after the sensor element is produced and then stretched once.
- the sensor element can be manufactured, for example, through the following steps. That is, (1) a step of producing a dielectric layer made of an elastomer composition (step (1)), and (2) A step of applying a composition containing carbon nanotubes and a dispersion medium to a dielectric layer to form an electrode layer (step (2)), It can manufacture by going through.
- a dielectric layer made of an elastomer composition is produced.
- an elastomer (or a raw material thereof) is added to a chain extender, a crosslinking agent, a vulcanization accelerator, a catalyst, a dielectric filler, a plasticizer, an antioxidant, an antioxidant, a colorant, etc.
- a raw material composition containing the additive is prepared.
- a dielectric layer is produced by molding this raw material composition.
- a conventionally well-known method can be employ
- a dielectric layer containing urethane rubber when forming a dielectric layer containing urethane rubber, the following method or the like can be used. First, a polyol component, a plasticizer, and an antioxidant are weighed and stirred and mixed for a certain time under heating and reduced pressure to prepare a mixed solution. Next, after measuring the mixed solution and adjusting the temperature, the catalyst is added and stirred with an agitator or the like. Thereafter, a predetermined amount of isocyanate component is added, and after stirring with an agitator or the like, the mixed solution is immediately poured into the molding apparatus shown in FIG. A sheet having a predetermined thickness is obtained. Thereafter, the dielectric layer can be produced by crosslinking after a certain time in a furnace.
- FIG. 4 is a schematic diagram for explaining an example of a molding apparatus used for producing a dielectric layer.
- the raw material composition 33 is poured into the gap between the protective films 31 made of polyethylene terephthalate (PET) that is continuously fed out from a pair of rolls 32, 32 that are spaced apart from each other. While proceeding with a curing reaction (crosslinking reaction) with the raw material composition 33 held in the gap, it was introduced into the heating device 34 and thermally cured with the raw material composition 33 held between the pair of protective films 31, A sheet-like dielectric layer 35 is formed.
- PET polyethylene terephthalate
- the dielectric layer may be prepared using a general-purpose film forming apparatus or film forming method such as various coating apparatuses, bar coaters, doctor blades, etc. after preparing the raw material composition.
- a general-purpose film forming apparatus or film forming method such as various coating apparatuses, bar coaters, doctor blades, etc. after preparing the raw material composition.
- Step (2) In this step, a composition containing carbon nanotubes and a dispersion medium (carbon nanotube dispersion) is applied, and then the dispersion medium is removed by a drying process to form an electrode layer integrated with the dielectric layer. .
- a composition containing carbon nanotubes and a dispersion medium carbon nanotube dispersion
- carbon nanotubes are added to the dispersion medium.
- a coating liquid carbon nanotube dispersion liquid
- each component including carbon nanotubes may be dispersed using an existing disperser such as an ultrasonic disperser, a jet mill, or a bead mill.
- dispersion medium examples include toluene, methyl isobutyl ketone (MIBK), alcohols, water, and the like. These dispersion media may be used independently and may be used together 2 or more types.
- the concentration of carbon nanotubes is preferably 0.01 to 10% by weight. If the concentration is less than 0.01% by weight, the concentration of the carbon nanotubes may be too thin, and it may be necessary to apply repeatedly. On the other hand, if it exceeds 10% by weight, the viscosity of the coating solution becomes too high, and the dispersibility of the carbon nanotubes decreases due to reaggregation, which may make it difficult to form a uniform electrode layer.
- the coating liquid is applied to a predetermined position on the surface of the dielectric layer by spray coating or the like and dried.
- the coating solution may be applied after masking a position where the electrode layer on the surface of the dielectric layer is not formed.
- the drying conditions for the coating solution are not particularly limited, and may be appropriately selected according to the type of the dispersion medium, the composition of the elastomer composition, and the like.
- coating the said coating liquid is not necessarily limited to spray coating. As other coating methods, for example, a screen printing method, an ink jet printing method, or the like can be employed.
- wirings and connection portions connected to the electrode layer are further formed as necessary.
- the wiring connected to the electrode layer is formed by, for example, applying the carbon nanotube dispersion liquid (coating liquid) to a predetermined portion and drying the same using the same method as that for forming the electrode layer. be able to. Further, the formation of the wiring may be performed simultaneously with the formation of the electrode layer.
- the connection portion can be formed, for example, by attaching a copper foil or the like to a predetermined end of the wiring.
- two dielectric layers made of an elastomer composition are prepared by the method of the above step (1).
- an electrode layer is formed on one surface of one dielectric layer and an electrode layer is formed on one surface of the other dielectric layer by the method of the above step (2).
- the two dielectric layers, each having an electrode layer are bonded together so that the electrode layers do not overlap each other.
- a wiring connected to the electrode layer and a connecting portion may be formed.
- a protective layer in the outermost layer of a front side and / or a back side.
- the protective layer is formed by, for example, producing a sheet-like material made of an elastomer composition using the same method as in the above step (1), cutting it into a predetermined size, and laminating it. Just do it.
- components second electrode layer, first dielectric layer, first electrode layer, (second dielectric layer) are sequentially formed thereon.
- the third electrode layer) and the front protective layer may be laminated to produce a sensor element.
- the sensor element can be manufactured through such steps.
- the sensor element shown in FIGS. 2A and 2B includes one detection unit.
- the number of detection units of the sensor element is not limited to one, and a plurality of detection units may be provided.
- a sensor element provided with a plurality of detection units for example, when a plurality of rows of strip-like electrode layers are formed on the front and back surfaces of the dielectric layer as the front-side electrode layer and the back-side electrode layer, And sensor elements arranged such that the rows of the front-side electrode layers and the rows of the back-side electrode layers are orthogonal to each other.
- a plurality of portions where the front side electrode layer and the back side electrode layer are opposed to each other with the dielectric layer interposed therebetween serve as a detection unit, and the detection units are arranged in a lattice shape.
- the measuring instrument is electrically connected to the sensor element.
- the measuring instrument has a function of measuring the capacitance C of the detection unit that changes according to deformation of the dielectric layer.
- a method of measuring the capacitance C a conventionally known method can be used. Therefore, the measuring instrument includes necessary capacitance measuring circuits, arithmetic circuits, amplifier circuits, power supply circuits, and the like.
- a method (circuit) for measuring the capacitance C for example, a CV conversion circuit (such as an LCR meter) using an automatic balancing bridge circuit, a CV conversion circuit using an inverting amplifier circuit, and a half-wave voltage doubler rectifier circuit are used. Examples thereof include a CV conversion circuit used, a CF oscillation circuit using a Schmitt trigger oscillation circuit, and a method using a combination of a Schmitt trigger oscillation circuit and an F / V conversion circuit.
- the electrical connection between the sensor element and the measuring instrument is preferably performed in the following manner from the viewpoint of eliminating the influence of noise during measurement.
- the sensor element has two dielectric layers (first and second dielectric layers) as shown in FIG. 3 and electrode layers (first to third dielectric layers) on both surfaces of each dielectric layer.
- the measuring device is a measuring device using a CF oscillation circuit that oscillates with the capacitance C and the resistance R of the detection unit and measures a change in capacitance, such as a Schmitt trigger oscillation circuit.
- the first electrode layer is connected to the oscillation block (detection block), and the second electrode layer and the third electrode layer are grounded (connected to the GND side).
- the sensor element is a sensor element having two dielectric layers as shown in FIG. 3 and electrode layers on both sides of each dielectric layer.
- the measuring instrument is a half-wave voltage doubler rectifier circuit or an inversion
- An AC signal generated by another block for example, an AC application device
- another block for example, an AC application device
- an AC impedance change due to a capacitance change of the sensor element is measured or an impedance change is used.
- the measuring instrument uses a CV conversion circuit that generates a voltage change.
- the sensor element is a sensor element having a single dielectric layer as shown in FIG. 2 and electrode layers on both sides thereof (front side electrode layer and back side electrode layer).
- the measuring instrument uses a CF conversion circuit such as a trigger oscillation circuit.
- the front electrode layer is connected to the oscillation block (detection block) in the measuring instrument
- the back electrode layer is grounded (connected to the GND side)
- the back surface of the sensor element is close to the living body. It is preferable to stick to.
- the sensor element is a sensor element having a single dielectric layer as shown in FIG. 2 and electrode layers on both sides thereof (front side electrode layer and back side electrode layer).
- a measuring instrument using a CV conversion circuit such as a voltage doubler rectifier circuit, an inverting amplifier circuit, or an automatic balanced bridge circuit.
- connect the front electrode layer to the detection block in the measuring instrument connect the back electrode layer to the block that generates the AC signal, and paste the sensor element so that the back surface is close to the living body.
- the influence of noise can be eliminated. As a result, the change in capacitance can be measured more accurately.
- the sensor device of the present invention may include a display as in the example shown in FIG. Thereby, the user of the sensor device can check information based on the change of the capacitance C related to the movement information of the living body in real time.
- the display includes a monitor, an arithmetic circuit, an amplifier circuit, a power supply circuit, and the like necessary for that purpose.
- the display device may include a storage unit such as a RAM, a ROM, and an HDD in order to store the measurement result of the capacitance C as in the example shown in FIG.
- a storage unit such as a RAM, a ROM, and an HDD in order to store the measurement result of the capacitance C as in the example shown in FIG.
- the display can check information based on a change in capacitance C related to biological exercise information and the like after training. Therefore, the practitioner can check the achievement level of the training, and it is also encouraging. Also, by confirming the degree of achievement of training, the information can be used to create a new training menu.
- the storage unit may be included in the measuring instrument.
- a terminal device such as a personal computer, a smartphone, or a tablet may be used.
- the measuring device 3 and the display device 4 are wired.
- these connections are not necessarily made in a wired manner, and may be connected wirelessly. Depending on how the sensor device is used, it may be easier to use if the measuring device and the display device are physically separated.
- the sensor device described above is used for measuring heart rate and respiratory rate, measuring momentum during sports training and rehabilitation training, evaluating motor functions, measuring stretch characteristics of sewn sportswear and supporters, and body movements. It can be used in various fields such as the evaluation of the follow-up quietness and the assistance of information transmission by conversation.
- the said sensor element can be utilized as a substitute of the interface of the myoelectric sensor of an electric prosthetic leg prosthesis.
- the sensor element can also be used as an input terminal of an input interface for a severely handicapped person.
- FIG. 5 is a perspective view for explaining a manufacturing process of the sensor element in the embodiment.
- Preparation of sensor element A with adhesive layer> For 100 parts by mass of polyol (Pandex GCB-41, manufactured by DIC), 40 parts by weight of plasticizer (dioctyl sulfonate) and isocyanate (Pandex GCA-11, manufactured by DIC) 17 .62 parts by weight were added and stirred and mixed with an agitator for 90 seconds to prepare a raw material composition for a dielectric layer. Next, the raw material composition is poured into the molding apparatus 30 shown in FIG. 4 and transported in a sandwich form with a protective film 31, and is cured by crosslinking under the conditions of a furnace temperature of 70 ° C. and a furnace time of 30 minutes.
- a roll-wound sheet with a predetermined thickness with a film was obtained. Then, after cross-linking in a furnace adjusted to 70 ° C. for 12 hours, a sheet made of a polyether urethane elastomer was produced. The obtained urethane sheet was cut into a size of 14 mm ⁇ 74 mm ⁇ thickness 70 ⁇ m, and one corner was cut off at a size of 7 mm ⁇ 7 mm ⁇ thickness 70 ⁇ m to produce a dielectric layer.
- the elongation at break was 505% and the relative dielectric constant was 5.8.
- the elongation at break was measured according to JIS K 6251.
- the dielectric constant is measured by measuring the capacitance at a measurement frequency of 1 kHz using an LCR high tester (manufactured by Hioki Electric Co., Ltd., 3522-50) after sandwiching a dielectric layer between 20 mm ⁇ electrodes, and then measuring the electrode area and the thickness of the measurement sample. From the above, the relative dielectric constant was calculated.
- Electrode layer material Highly oriented carbon nanotubes manufactured by Taiyo Nippon Sanso Co., Ltd., which are multi-walled carbon nanotubes manufactured by the substrate growth method (4 to 12 layers, fiber diameter 10 to 20 nm, fiber length 150 to 30 mg of 300 ⁇ m, carbon purity 99.5%) is added to 30 g of methyl isobutyl ketone (MIBK), and wet dispersion is performed using a jet mill (Nanojet PAL JN10-SP003, manufactured by Joko), and diluted 10 times. Thus, a carbon nanotube dispersion liquid having a concentration of 0.01% by weight was obtained.
- MIBK methyl isobutyl ketone
- the obtained mixture was formed on a PET film (50E-0010KF, manufactured by Fujimori Kogyo Co., Ltd.) having a release treatment on the surface with a wet film thickness of 100 ⁇ m using an applicator. And cured at 100 ° C. for 30 minutes to prepare an adhesive layer having a thickness of 25 ⁇ m after curing.
- a PET film 50E-0010KF, manufactured by Fujimori Kogyo Co., Ltd.
- FIGS. 5 (a) to 5 (d) Fabrication of sensor element A sensor element was fabricated through the fabrication steps shown in FIGS. 5 (a) to 5 (d).
- a mask (not shown) in which an opening having a predetermined shape was formed on a PET film that had been subjected to a release treatment was attached to one surface (front surface) of the back-side protective layer 25B produced in the step (3).
- the mask is provided with openings corresponding to the back electrode layer and the back wiring, and the size of the opening is 10 mm wide ⁇ 60 mm long corresponding to the back electrode layer, and the portion corresponding to the back wiring. It is 5 mm wide x 10 mm long.
- the dielectric layer 21 produced in the step (1) was laminated on the back side protective layer 25B so as to cover the entire back side electrode layer 22B and a part of the back side wiring 23B. Further, the front side electrode layer 22A and the front side wiring 23A were formed on the front side of the dielectric layer 21 using the same method as the formation of the back side electrode layer 22B and the back side wiring 23B (see FIG. 5B).
- the front side prepared in the step (3) so that the front side of the dielectric layer 21 on which the front side electrode layer 22A and the front side wiring 23A are formed covers the entire front side electrode layer 22A and a part of the front side wiring 23A.
- the protective layer 25A was laminated by lamination. Furthermore, copper foil was attached to the respective end portions of the front side wiring 23A and the back side wiring 23B to form the front side connection portion 24A and the back side connection portion 24B (see FIG. 5C). Thereafter, lead wires 29 serving as external wirings were fixed to the front side connection portion 24A and the back side connection portion 24B with solder.
- an acrylic adhesive tape (manufactured by 3M, Y-4905 (thickness 0.5 mm)) is applied to the PET film 27 having a thickness of 100 ⁇ m on the portion of the front side connecting portion 24A and the back side connecting portion 24B located on the back side protective layer 25B. ) 26 for reinforcement.
- the adhesive layer 28 produced in (4) above was attached to the back side of the back side protective layer 25B with a hand roller to complete the sensor element 222 (see FIG. 5D).
- the dielectric layer 21 corresponds to the first dielectric layer
- the front electrode layer 22A corresponds to the first electrode layer
- the back electrode layer 22B corresponds to the second electrode layer.
- the sensor element 222 manufactured through the above (1) to (5) was connected to an LCR meter (manufactured by Hioki Electric Co., Ltd., LCR HiTester 3522-50) via a lead wire to obtain a sensor device. Examples 1 to 4 were performed as operation verification of the manufactured sensor device.
- Example 1 Measurement of bending and stretching of elbow
- the sensor element 222 was attached to the elbow portion of the left hand of the subject via the adhesive layer 28. Thereafter, while the sensor element was attached, bending of the left elbow was performed so that the bending amount gradually increased, and the change in capacitance at that time was measured.
- the results are shown in FIG.
- the graph of FIG. 6B it has been clarified that in the bending and stretching motion of the elbow joint, the capacitance gradually increases as the bending amount gradually increases.
- Example 2 Respiration measurement
- the sensor element 222 was attached to the left chest of the subject via the adhesive layer 28. Then, with the sensor element attached, three types of operations were performed: (1) stop breathing for 10 seconds, (2) perform natural breathing for 10 seconds, and (3) perform large breathing for 10 seconds.
- the electrostatic capacity was measured. The results are shown in FIG. As shown in the graph of FIG. 7B, the electrostatic capacity hardly changes in the operation (1), and in the operations (2) and (3), the electrostatic capacity varies depending on the magnitude of respiration. It became clear that capacity increased. Further, in the operations (2) and (3), it was estimated that about 2.5 breaths were performed in 10 seconds.
- Example 3 Measurement of vocal sound
- the sensor element 222 was attached to the left cheek of the subject via the adhesive layer 28.
- the results are shown in FIG.
- the capacitance changes according to the type of the utterance sound “Ai, U, E, O”.
- Example 4 Measurement of pulse rate (heart rate)
- the capacitance for 10 seconds was measured in an unstretched state.
- the sensor element 222 was attached to the subject's carotid artery (where the pulse touches) via the adhesive layer 28.
- the capacitance for 10 seconds was measured in a normal state.
- the subject performed a stepping exercise (200 times / 60 seconds) for 60 seconds while sitting on a chair.
- the breath was adjusted for 10 seconds, and then the capacitance was measured for 10 seconds. .
- FIG. 9 (b) The results are shown in FIG. 9 (b).
- the pulse for 10 seconds was counted with the left wrist. (2) 12 times in normal times, (3) 17 times after exercise, which is the same as the result of FIG. 9B. I did it. From these, it became clear that the heart rate can be measured from the change in capacitance.
- the sensor element B produced by the following method is connected to a measuring instrument using any one of an automatic balanced bridge circuit (LCR meter), an inverting amplifier circuit, a Schmitt trigger oscillation circuit, and a half-wave voltage doubler rectifier circuit. Or a voltage having a correlation with capacitance). Based on the measurement results, the influence on the measurement accuracy by the type of measuring instrument and the connection method between the sensor element and the measuring instrument was evaluated.
- LCR meter automatic balanced bridge circuit
- inverting amplifier circuit a Schmitt trigger oscillation circuit
- a half-wave voltage doubler rectifier circuit or a half-wave voltage doubler rectifier circuit. Or a voltage having a correlation with capacitance
- a sensor element B was prepared in the same manner as the sensor element A described above except that the dielectric layer had a thickness of 100 ⁇ m and no adhesive layer was formed. Therefore, in the sensor element B, the back side protective layer (50 ⁇ m), the back side electrode layer, the dielectric layer (100 ⁇ m), the front side electrode layer, and the front side protective layer (50 ⁇ m) are laminated in this order from the back side to the front side. Yes.
- the sensor element was placed on a polypropylene plate and placed on a polypropylene plate and connected to each measuring instrument. Normal measurement) and measurement with three fingers placed on the surface of the front protective layer (measurement with fingers placed) were performed. Then, the percentage (%) of the absolute value of the difference between the measurement value of the normal measurement and the measurement value of the measurement with the finger placed on the measurement value of the normal measurement was calculated as an error (%).
- Example 5 An automatic balancing bridge circuit (LCR meter: manufactured by Hioki Electric Co., Ltd., LCR HiTester 3522-50) was used as a measuring instrument, and a four-terminal probe (manufactured by Hioki Electric Co., model number 9140) was used as a measuring probe. This was connected to a sensor element and the capacitance was measured. At this time, the wiring condition in which the front electrode layer is connected to the Lo terminal and the back electrode layer is connected to the Hi terminal is positively connected, and conversely, the front electrode layer is connected to the Hi terminal and the back electrode layer is connected to the Lo terminal. The condition was reverse connection. Under the respective wiring conditions of the normal connection and the reverse connection, the normal measurement and the measurement with the finger placed thereon were performed. The results are shown in Table 1.
- Example 6 An inverting amplifier circuit 300 as shown in FIG. 10 was used as a measuring instrument, and this was connected to the sensor element 310 to measure the capacitance.
- the oscillation frequency of the AC applying device 311 is 5 kHz
- the capacitance of the feedback capacitor 313 is 329.2 pF
- the resistance value of the feedback resistor 314 is 4.7 M ⁇ .
- reference numeral 315 denotes a BEF (band elimination filter).
- the front electrode layer is connected to the AC applying device 311
- the wiring condition in which the back electrode layer is connected to the operational amplifier 312 is positively connected
- conversely, the front electrode layer is connected to the operational amplifier 312 and the back electrode layer is AC applied.
- the wiring condition connected to the device 311 was reverse connection. Under the respective wiring conditions of the normal connection and the reverse connection, the normal measurement and the measurement with the finger placed thereon were performed. The results are shown in Table 1.
- Example 7 A Schmitt trigger oscillation circuit 400 as shown in FIG. 11 was used as a measuring instrument, and this was connected to the sensor element 410, and the capacitance was measured from the Schmitt trigger 412 from the output frequency.
- the resistance value of the variable resistor 413 was adjusted so that the oscillation frequency was 5 kHz in the normal connection of normal measurement.
- the wiring condition in which the front electrode layer is grounded and the back electrode layer is connected to the Schmitt trigger 412 side is normally connected, and conversely, the wiring condition in which the front electrode layer is connected to the Schmitt trigger 412 side and the back electrode layer is grounded is Reverse connection was used. Under the respective wiring conditions of the normal connection and the reverse connection, the normal measurement and the measurement with the finger placed thereon were performed. The results are shown in Table 1.
- Example 8 A half-wave voltage doubler rectifier circuit 500 as shown in FIG. 12 was used as a measuring instrument, and this was connected to the sensor element 510 to measure the output voltage.
- the oscillation frequency of the AC applying device 511 is 5 kHz
- the capacitance of the capacitor 512 is 0.1 ⁇ F
- the resistance value of the resistor 513 is 470 k ⁇ .
- the diodes 514 and 515 Schottky diodes were used as the diodes 514 and 515.
- the front side electrode layer is connected to the AC applying device 511, the wiring condition in which the back side electrode layer is connected to the OUTPUT side is positively connected, and conversely, the front side electrode layer is connected to the OUTPUT side, and the back side electrode layer is connected to the AC applying device 511.
- the wiring condition connected to was defined as reverse connection. Under the respective wiring conditions of the normal connection and the reverse connection, the normal measurement and the measurement with the finger placed thereon were performed. The results are shown in Table 1.
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Abstract
Description
また、医療の分野においても、患者や介護を要する高齢者の心拍数や呼吸数をモニタリングすることが日常的に行われている。
しかしながら、これらの方法では、肘や膝の関節の曲り具合は計測できても、例えば肩甲骨の動きや臀部の動き、表情の動きなど計測が困難な部位も多く存在する。
また、より大きな身体の動きを計測する方法としてモーションキャプチャーを利用した計測方法も提案されている(例えば、特許文献1参照)。しかしながら、モーションキャプチャーを利用した方法は、計測システム全体として大がかりなシステムが必要であるため計測システムの携帯が困難で、かつ、測定前の準備が煩雑であり、更に、撮像手段(カメラ)の陰になる部分の運動は計測することができないとの課題があった。
また、静電容量型圧力センサは、誘電層の厚さ方向の変形による静電容量に変化を計測するセンサであるため、そもそも誘電層の面方向の変形を計測することは困難であり、身体の運動状態を計測することができなかった。
本発明のセンサ装置は、エラストマー組成物からなるシート状の第1誘電層と、カーボンナノチューブを含有する導電性組成物からなり、上記第1誘電層の表面及び裏面のそれぞれに上記第1誘電層を挟んで少なくとも一部が対向するよう形成された第1電極層及び第2電極層とを有し、上記第1電極層及び第2電極層の対向する部分を検出部とし、上記第1誘電層の表裏面の面積が変化するように可逆的に変形するセンサ素子と、
上記検出部における静電容量の変化を計測する計測器とを備え、
生体に貼り付けて使用され、生体表面の変形の追跡に用いられることを特徴とする。
また、上記センサ装置は、上記センサ素子が上記生体表面に被覆材を介して貼り付けられ、上記生体表面の変形に基づいて、生命活動情報、生体の運動情報及び上記被覆材の変形情報のうちの少なくとも1つを計測するものであることも好ましい。
また、上記センサ装置では、上記計測器が、反転増幅回路、半波倍電圧整流回路又は自動平衡ブリッジ回路を用いて静電容量の変化を計測する計測器であり、上記センサ素子が、裏面側が生体に近接するように貼り付けられ、上記第1誘電層の裏面に形成された第2電極層が、上記計測器の交流信号を生成する側に接続されることも好ましい。
本発明のセンサ装置は、センサ素子と計測器とを備え、生体に貼り付けて使用され、生体表面の変形の追跡に用いられる。
上記センサ素子は、エラストマー組成物からなるシート状の第1誘電層と、カーボンナノチューブを含有する導電性組成物からなり、上記第1誘電層の表面及び裏面のそれぞれに上記第1誘電層を挟んで少なくとも一部が対向するよう形成された第1電極層及び第2電極層とを有し、上記第1電極層及び第2電極層の対向する部分を検出部とし、上記第1誘電層の表裏面の面積が変化するように可逆的に変形する。
上記計測器は、上記検出部における静電容量の変化を計測する。
図2(a)は本発明のセンサ装置を構成するセンサ素子の一例を模式的に示す斜視図であり、(b)は(a)のA-A線断面図である。
計測器3は、静電容量Cを周波数信号Fに変換するためのシュミットトリガ発振回路3a、周波数信号Fを電圧信号Vに変換するF/V変換回路3b、電源回路(図示せず)を備える。計測器3は、センサ素子2の検出部で検出された静電容量Cを周波数信号Fに変換した後、更に電圧信号Vに変換し、表示器4に送信する。
表示器4は、モニター4a、演算回路4b、記憶部4cを備える。表示器4は、計測器3で測定された上記静電容量Cの変化をモニター4aに表示させるとともに、上記静電容量Cの変化を記録データとして記憶する。
本発明において、センサ素子が備える表側電極層と裏側電極層とは、必ずしも誘電層を挟んでその全体が対向している必要はなく、少なくともその一部が対向していればよい。
センサ素子2では、誘電層11が第1誘電層に、表側電極層12Aが第1電極層に、裏側電極層12Bが第2電極層に、それぞれ相当する。
そして、センサ装置1では、センサ素子2の変形に伴い、上記検出部の静電容量が誘電層11の変形量と相関をもって変化する。よって、静電容量の変化を検出することで、センサ素子2の変形量を検出することができる。
本発明のセンサ装置では、上記センサ素子を生体に貼り付けた状態で上記検出部の静電容量を測定すると、生体表面の変形に応じて上記検出部の静電容量の値が変化する。そのため、上記静電容量の変化に基づいて生体表面の変形を追跡することができ、その追跡結果から種々の情報を取得することができる。
以下、上記センサ装置の使用態様について説明する。
本発明のセンサ装置は、上記センサ素子を皮膚等の生体表面に直接貼り付けて使用することができる。
この場合、上記センサ素子は、上記生体表面の変形(伸長・萎縮、膨張・収縮など)に追従して伸縮するため、生体表面の変形量に応じて検出部の静電容量が変化することとなる。そのため、上記検出部の静電容量を計測することにより、生体表面の変形量を測定することができる。そして、生体表面の変形量を測定することにより、生体表面の変形と相関する生命活動情報や生体の運動情報を取得することができる。
また、上記センサ装置が取得することのできる上記生体の運動情報は特に限定されず、運動時の筋肉の収縮によって、生体表面が伸縮する運動であればその運動状態を測定することができる。上記生体の運動情報としては、例えば、関節を曲げた際の曲げ量(曲げ角度)や、発音・発声時の頬の動き、表情筋の動き、肩甲骨の動き、臀筋の動き、背中の動き、腰の曲がり具合、胸の膨らみ、筋肉の収縮による太ももやふくらはぎの収縮の大きさ、飲み込み時の喉の動き、足の動き、手の動き、指の動き、足裏の動き、まばたきの動き、皮膚の伸び易さ(しなやかさ)等が挙げられる。
表情筋のトレーニングとして、例えば、左右対称にセンサ素子を貼り付けることで、皮膚の動きを定量的に計測したり、リアルタイムに可視化したりすることができる。その結果、左右の信号波形を見ながら、信号が重なるように意識してトレーニングしたり、左右対称な自然な表情に機能回復させるリハビリトレーニングをしたりすることが可能となる。
本発明のセンサ装置は、上記センサ素子を生体表面に被覆材を介して貼り付けて使用することもできる。
ここで、上記被覆材としては、例えば、衣類、サポーター、包帯やテーピングテープ等が挙げられる。上記衣類としては、着用時に皮膚に密着するタイプのものが好ましく、具体例としては、例えば、トレーニング用アンダーウエアやスイムウエア等が挙げられる。
上記センサ装置では、上記センサ素子を生体表面に被覆材を介して貼り付けて使用する場合にも、上記センサ素子を生体表面に直接貼り付けて使用する場合と同様、生命活動情報や生体の運動情報を取得することができる。
例えば、上記センサ素子をトレーニング用アンダーウエアに貼り付け、その状態で運動を行った場合、身体の動きに追従してトレーニング用アンダーウエアの生地が伸ばされたり元の状態に戻されたりと生地が変形する。そのため、この生地の変形(伸縮)に応じて静電容量が変化することとなる。よって、静電容量の値や変化の仕方に基づいてトレーニング用アンダーウエア(被覆材)の変形を計測することができる。
また、上記センサ装置が、上記センサ素子を2個以上備える場合には、例えば、身体に左右対称(例えば、右足の甲と左足の甲)にセンサ素子を貼り付け、その状態で足踏みを行うことにより、左右の足の動きのバランスを計測することができる。
また、例えば、左右の足首、膝関節、股関節にそれぞれセンサ素子を貼り付け、その状態で歩行を行うことにより、左右の足の動きのバランス、各可動部位の曲げ量、各可動部位の動きのリズムを測定することができる。更には、例えば、靴形状やマット形状の圧力分布センサ製品等の既存の歩行計測機器と併用して用いることで、より高度な歩行運動の情報を得ることもできる。
これらの情報はスポーツトレーニングやリハビリトレーニングのメニューを決定する情報として有効である。
図3(a)は、本発明のセンサ装置を構成するセンサ素子の別の一例を模式的に示す斜視図であり、(b)は、(a)のB-B線断面図である。
図3(a)及び(b)に示すセンサ素子2′は、エラストマー組成物からなるシート状の第1誘電層41Aと、第1誘電層41Aの表面(おもて面)に形成された第1電極層42Aと、第1誘電層41の裏面に形成された第2電極層42Bと、第1誘電層41Aの表側に第1電極層42Aを覆うように積層された第2誘電層41Bと、第2誘電層41Bの表面に形成された第3電極層42Cとを備える。更に、センサ素子2′は、第1電極層42Aに連結された第1配線43Aと、第2電極層42Bに連結された第2配線43Bと、第3電極層42Cに連結された第3配線43Cと、第1配線43Aの第1電極層42Aと反対側の端部に取り付けられた第1接続部44Aと、第2配線43Bの第2電極層42Bと反対側の端部に取り付けられた第2接続部44Bと、第3配線43Cの第3電極層42Cと反対側の端部に取り付けられた第3接続部44Cとを備える。また、センサ素子2′では、第1誘電層41Aの裏側及び第2誘電層41Bの表側のそれぞれに裏側保護層45B及び表側保護層45Aが設けられている。
なお、センサ素子2′は、図2に示したセンサ素子2と同様、粘着層を備えていてもよい。
本発明のセンサ装置は、センサ素子を生体に貼り付けて使用し、生体表面の変形を追跡するセンサ装置である。上記センサ素子を生体に貼り付けた場合、生体表面は導体であるため、生体表面が電極層に直接接触した場合は勿論のこと、保護層を介して接触した場合も、生体と接触又は近接していること自体がノイズの発生原因となる。
これに対して、第1電極層及び第2電極層を計測器と適切に接続することにより、ノイズによる測定誤差を排除し、正確に静電容量の変化を測定することができる。更に、図3に示したような、第1誘電層、第1電極層及び第2電極層に加えて、第2誘電層及び第3電極層を有するセンサ素子では、表裏面の区別なく測定誤差を排除したり、両面からのノイズによる測定誤差を排除したりすることができる。
その結果、生命活動情報や生体の運動情報、被覆材の変形情報をより正確に計測することができる。なお、センサ素子と計測器の接続方法については後述する。
<センサ素子>
<<誘電層(第1誘電層及び第2誘電層)>>
上記誘電層はエラストマー組成物からなるシート状物であり、その表裏面の面積が変化するように可逆的に変形することができる。本発明において、シート状の誘電層に表裏面とは、誘電層の表(おもて)面及び裏面を意味する。
上記エラストマー組成物としては、エラストマーと、必要に応じて他の任意成分とを含有するものが挙げられる。
上記エラストマーとしては、例えば、天然ゴム、イソプレンゴム、ニトリルゴム(NBR)、エチレンプロピレンゴム(EPDM)、スチレン・ブタジエンゴム(SBR)、ブタジエンゴム(BR)、クロロプレンゴム(CR)、シリコーンゴム、フッ素ゴム、アクリルゴム、水素添加ニトリルゴム、ウレタンゴム等が挙げられる。これらは単独で用いてもよいし、2種以上併用してもよい。
これらのなかでは、ウレタンゴム、シリコーンゴムが好ましい。永久歪み(または永久伸び)が小さいからである。更に、シリコーンゴムに比べ、カーボンナノチューブとの密着性に優れる点から、ウレタンゴムが特に好ましい。
上記エステル系ポリオールとしては、例えば、ポリライト8651(DIC社製)等が挙げられる。
上記エーテル系ポリオールとしては、例えば、ポリオキシテトラメチレングリコール、PTG-2000SN(保土谷化学工業社製)、ポリプロピレングリコール、プレミノールS3003(旭硝子社製)、パンデックスGCB-41(DIC社製)等が挙げられる。
また、上記ウレタンゴムを合成する際には、その反応系中に必要に応じて、鎖延長剤、架橋剤、触媒、加硫促進剤等を加えてもよい。
ここで、30%以上増大するように変形可能であるとは、荷重をかけて面積を30%増大させても破断することがなく、かつ、荷重を解放すると元の状態に復元する(即ち、弾性変形範囲にある)ことを意味する。上記誘電層の表裏面の面積の増大するように変形可能な範囲は、50%以上であることがより好ましく、100%以上であることが更に好ましく、200%以上であることが特に好ましい。
なお、上記誘電層の面方向の変形可能な範囲は誘電層の設計(材質や形状等)により制御することができる。
誘電層が軟らかすぎると高品質な加工が難しく、充分な測定精度を確保することができない場合がある。一方、誘電層が硬すぎると、生体表面の変形を阻害するおそれがある。
上記電極層(表側電極層及び裏側電極層)は、カーボンナノチューブを含有する導電性組成物からなるものである。
上記カーボンナノチューブとしては公知のカーボンナノチューブを使用することができる。上記カーボンナノチューブは、単層カーボンナノチューブ(SWNT)であってもよいし、2層カーボンナノチューブ(DWNT)又は3層以上の多層カーボンナノチューブ(MWNT)であってもよい(本明細書では、両者を合わせて単に多層カーボンナノチューブと称する)。更に、本発明では、層数の異なるカーボンナノチューブを2種以上併用してもよい。
また、各カーボンナノチューブの形状(平均長さや繊維径、アスペクト比)も特には限定されず、センサ装置の使用目的や、センサ素子に要求される導電性や耐久性、更には電極層を形成するための処理や費用を総合的に判断して適宜選択すればよい。
これに対し、カーボンナノチューブの平均長さが10μm未満では、電極層の変形に伴って電気抵抗が増大したり、電極層を繰返し伸縮させた際に電気抵抗のバラツキが大きくなったりする場合がある。特に、センサ素子(誘電層)の変形量が大きくなった場合にこのような不都合が発生しやすくなる。
また、上記カーボンナノチューブの平均長さは、例えば、カーボンナノチューブの観察画像から無作為に選んだ10箇所のカーボンナノチューブの繊維長さに基づき平均値を算出すればよい。
上記繊維径が0.5nm未満では、カーボンナノチューブの分散が悪くなり、その結果、導電パスが広がらず、電極層の導電性が不充分になることがある。一方、30nmを超えると、同じ重量でもカーボンナノチューブの本数が少なくなり、導電性が不充分になることがある。カーボンナノチューブの平均繊維径は5~20nmがより好ましい。
単層カーボンナノチューブを用いた場合、上述した好ましい範囲の平均長さを有するカーボンナノチューブを用いた場合でも、電気抵抗が高くなったり、伸長時に電気抵抗が大きく増大したり、繰り返し伸縮時に電気抵抗が大きくばらついたりすることがある。
これについては次のように推測している。即ち、単層カーボンナノチューブは、通常、金属性カーボンナノチューブと半導体性カーボンナノチューブとの混合物として合成されるため、この半導体性カーボンナノチューブの存在が、電気抵抗が高くなったり、伸長時に電気抵抗が大きく増大したり、繰り返し伸縮時に電気抵抗が大きくばらついたりする原因となっていると推測している。
なお、金属性カーボンナノチューブと半導体性カーボンナノチューブとを分離し、平均長さの長い金属性の単層カーボンナノチューブを用いれば、平均長さの長い多層カーボンナノチューブを用いた場合と同様の電気特性を備えた電極層を形成することができる可能性がある。しかしながら、金属性カーボンナノチューブと半導体性カーボンナノチューブとの分離は容易ではなく(特に、繊維長さの長いカーボンナノチューブにおいて)、両者の分離には煩雑な作業が必要となる。そのため、電極層を形成する際の作業容易性、及び、経済性の観点からも上述した通り、上記カーボンナノチューブとしては多層カーボンナノチューブが好ましい。
基板成長法は、CVD法の1種であり、基板上に塗布した金属触媒に炭素源を供給することで成長させてカーボンナノチューブを製造する方法である。基板成長法は、比較的繊維長さが長く、かつ、繊維長さの揃ったカーボンナノチューブを製造するのに適した製造方法である。そのため、本発明で使用するカーボンナノチューブの製造方法として適している。
上記カーボンナノチューブが基板製造法により製造されたものである場合、カーボンナノチューブの繊維長さは、CNTフォレストの成長長さと実質的に同一である。そのため、このカーボンナノチューブの繊維長さを電子顕微鏡を用いて測定する場合は、CNTフォレストの成長長さを測定すればよい。
上記バインダー成分はつなぎ材料として機能し、上記バインダー成分を含有させることにより、電極層と誘電層との密着性、及び、電極層自体の強度を向上させることができる。更に、上記バインダー成分を含有する場合、後述の方法で電極層を形成する際にカーボンナノチューブの飛散を抑制することができるため、電極層形成時の安全性も高めることができる。
また、上記バインダー成分としては、生ゴム(天然ゴム及び合成ゴムの加硫させていない状態のもの)も使用することができる。生ゴムのように比較的弾性の弱い材料を用いることで、誘電層の変形に対する電極層の追従性も高めることができる。
上記バインダー成分は、特に、誘電層を構成するエラストマーと同種のものが好ましい。誘電層と電極層との密着性を顕著に向上させることができるからである。
上記センサ素子では、電極層が実質的にカーボンナノチューブのみで形成されていてもよい。この場合も誘電層との間で充分な密着性を確保することができる。この場合、カーボンナノチューブと誘電層とはファンデルワールス力等により強固に密着している。
また、カーボンナノチューブの含有量を高めれば、電極層の導電性を向上させることができる。そのため、電極層を薄くしても要求される導電性を確保することができ、その結果、電極層を薄くしたり、電極層の柔軟性を確保したりすることがより容易になる。
一方、上記平均厚さが0.1μm未満では、導電性が不足し、センサ素子としての測定精度が低下するおそれがある。一方、上記平均厚さが、10μmを超えるとカーボンナノチューブの補強効果によりセンサ素子が硬くなり、センサ素子の伸縮性が低下する。その結果、上記センサ素子を生体表面に直接又は被覆材を介して貼り付けた際に生体表面の変形が阻害されることがある。
上記センサ素子は、図2、3に示した例のように、必要に応じて、電極層と接続された第1配線(表側配線)や第2配線(裏側配線)、第3配線が形成されていてもよい。
これらの各配線は、誘電層の変形を阻害せず、かつ、誘電層が変形しても導電性が維持されるものであればよい。具体例としては、例えば、上記電極層と同様の導電性組成物からなるものが挙げられる。
更に、上述した各配線それぞれの電極層と反対側の端部には、図2、3に示した例のように、必要に応じて、外部配線と接続するための第1接続部(表側接続部)、第2接続部(裏側接続部)、第3接続部が形成されていてもよい。これらの各接続部としては、例えば、銅箔等を用いて形成されたものが挙げられる。
上記保護層の材質は特に限定されず、その要求特性に応じて適宜選択すればよい。その具体例としては、例えば、上記誘電層の材質と同様のエラストマー組成物等が挙げられる。
上記粘着層としては特に限定されず、例えば、アクリル系粘着剤、ゴム系粘着剤、シリコーン系粘着剤等からなる層が挙げられる。
ここで、各粘着剤は、溶剤型であってもよいし、エマルジョン型であってもよいし、ホットメルト型でもよい。上記粘着剤は、センサ装置の使用態様等に応じて適宜選択して用いればよい。ただし、上記粘着層は、上記誘電層の伸縮を阻害しない柔軟性が必要である。
(1)エラストマー組成物からなる誘電層を作製する工程(工程(1))、及び、
(2)カーボンナノチューブ及び分散媒を含む組成物を誘電層に塗布し、電極層を形成する工程(工程(2))、
を経ることより製造することができる。
本工程では、エラストマー組成物からなる誘電層を作製する。
まず、原料組成物としてエラストマー(又はその原料)に、必要に応じて、鎖延長剤、架橋剤、加硫促進剤、触媒、誘電フィラー、可塑剤、酸化防止剤、老化防止剤、着色剤等の添加剤を配合した原料組成物を調製する。次に、この原料組成物を成形することにより誘電層を作製する。なお、成形方法としては従来公知の手法を採用することができる。
まず、ポリオール成分、可塑剤及び酸化防止剤を計量し、加熱、減圧下において一定時間撹拌混合し、混合液を調製する。次に、混合液を計量し、温度を調整した後、触媒を添加しアジター等で撹拌する。その後、所定量のイソシアネート成分を添加し、アジター等で撹拌後、即座に混合液を図4に示す成形装置に注入し、保護フィルムでサンドイッチ状にして搬送しつつ架橋硬化させ、保護フィルム付きの所定厚みのシートを得る。その後、炉で一定時間後架橋させることで誘電層を製造することができる。
本工程では、カーボンナノチューブ及び分散媒を含む組成物(カーボンナノチューブ分散液)を塗布し、その後、乾燥処理にて分散媒を除去することにより、上記誘電層と一体化された電極層を形成する。
次に、カーボンナノチューブを含む各成分を湿式分散機を用いて分散媒中に分散(又は溶解)させることより塗布液(カーボンナノチューブ分散液)を調製する。具体的には、例えば、超音波分散機、ジェットミル、ビーズミルなど既存の分散機を用いてカーボンナノチューブを含む各成分を分散させればよい。
上記塗布液の乾燥条件は特に限定されず、分散媒の種類やエラストマー組成物の組成等に応じて適宜選択すればよい。
また、上記塗布液を塗布する方法は、スプレーコートに限定されるわけではない。他の塗布方法としては、例えば、スクリーン印刷法、インクジエット印刷法等も採用することができる。
上記電極層と接続された配線の形成は、例えば、上記電極層の形成と同様の方法を用いて、所定の箇所に上記カーボンナノチューブ分散液(塗布液)を塗布し、乾燥させること等により行うことができる。また、上記配線の形成は上記電極層の形成と同時に行ってもよい。
上記接続部の形成は、例えば、上記配線の所定の端部に銅箔等を取り付けること等により行うことができる。
上記保護層の形成は、例えば、上記(1)の工程と同様の方法を用いてエラストマー組成物からなるシート状物を作製した後、所定のサイズに裁断し、それをラミネートすること等により行えばよい。
また、保護層を備えたセンサ素子を作製する場合は、裏側の保護層から出発し、その上に順次構成部材(第2電極層、第1誘電層、第1電極層、(第2誘電層、第3電極層)、表側保護層)を積層することにより、センサ素子を作製してもよい。
このような工程を経ることにより、上記センサ素子を製造することができる。
複数の検出部を備えたセンサ素子の具体例としては、例えば、表側電極層及び裏側電極層として複数列の帯状の電極層が誘電層の表面及び裏面に形成され、かつ、平面視した際に、表側電極層の列と裏側電極層の列とが直交するように配置されたセンサ素子が挙げられる。このようなセンサ素子では表側電極層及び裏側電極層が誘電層を挟んで対向する複数の部分が検出部となり、その検出部が格子状に配置されていることとなる。
上記計測器は、上記センサ素子と電気的に接続されている。上記計測器は、上記誘電層の変形に応じて変化する上記検出部の静電容量Cを測定する機能を有する。上記静電容量Cを測定する方法としては従来公知の方法を用いることができる。そのため、上記計測器は、必要となる静電容量測定回路、演算回路、増幅回路、電源回路等を備えている。上記静電容量Cを測定する方法(回路)としては、例えば、自動平衡ブリッジ回路を利用したCV変換回路(LCRメータなど)、反転増幅回路を利用したCV変換回路、半波倍電圧整流回路を利用したCV変換回路、シュミットトリガ発振回路を用いたCF発振回路、シュミットトリガ発振回路とF/V変換回路とを組み合わせて用いる方法等が挙げられる。
(1-1)上記センサ素子が、図3に示したような2層の誘電層(第1及び第2誘電層)と各誘電層の両面に電極層(第1~第3誘電層)を有するセンサ素子であり、計測器がシュミットトリガ発振回路のような、検出部の静電容量Cと抵抗Rで発振して静電容量の変化を計測するCF発振回路を用いた計測器である場合。
この場合には、第1電極層を発振ブロック(検出ブロック)に接続し、第2電極層及び第3電極層を接地する(GND側に接続する)ことが好ましい。
このようにセンサ素子と計測器とを接続することにより、センサ素子の表側及び裏側のいずれを生体に近接するように接続してもノイズの影響を排除することができる。その結果、より正確に静電容量の変化を計測することができる。
この場合には、第1電極層を検出ブロックに接続し、第2電極層及び第3電極層を交流信号を生成するブロックに接続することが好ましい。
このようにセンサ素子と計測器とを接続することにより、センサ素子の表側及び裏側のいずれを生体に近接するように接続してもノイズの影響を排除することができる。その結果、より正確に静電容量の変化を計測することができる。
この場合には、表側電極層を計測器内の発振ブロック(検出ブロック)に接続し、裏側電極層を接地し(GND側に接続し)、かつ、上記センサ素子を裏面側が生体に近接するように貼り付けることが好ましい。
このような向きでセンサ素子を生体に貼り付け、上記のようにセンサ素子と計測器とを接続することにより、ノイズの影響を排除することができる。その結果、より正確に静電容量の変化を計測することができる。
この場合には、表側電極層を計測器内の検出ブロックに接続し、裏側電極層を交流信号を生成するブロックに接続し、かつ、上記センサ素子を裏面側が生体に近接するように貼り付けることが好ましい。
このような向きでセンサ素子を生体に貼り付け、上記のようにセンサ素子と計測器とを接続することにより、ノイズの影響を排除することができる。その結果、より正確に静電容量の変化を計測することができる。
本発明のセンサ装置は、図1に示した例のように表示器を備えていてもよい。これにより上記センサ装置の使用者は、生体の運動情報等に関する静電容量Cの変化に基づく情報をリアルタイムで確認することができる。上記表示器は、そのために必要となるモニター、演算回路、増幅回路、電源回路等を備えている。
上記表示器は、例えば、本発明のセンサ装置をスポーツトレーニングやリハビリトレーニングの実施者に使用する場合、生体の運動情報等に関する静電容量Cの変化に基づく情報をトレーニング後に確認することができる。そのため、実施者はトレーニングの達成度を確認することができ、実施者の励みにもなる。また、トレーニングの達成度を確認することにより、その情報を新たなトレーニングメニューの作成に生かすことができる。
なお、上記記憶部は、上記計測器が備えていてもよい。
上記表示器としては、パソコン、スマートフォン、タブレット等の端末機器を利用してもよい。
また、本発明のセンサ装置では、上記センサ素子が、重度心身障害者の入力インターフェースの入力端末としても使用することができる。
図5は、実施例におけるセンサ素子の作製工程を説明するための斜視図である。
(1)誘電層の作製
ポリオール(パンデックスGCB-41、DIC社製)100質量部に対して、可塑剤(ジオクチルスルホネート)40重量部と、イソシアネート(パンデックスGCA-11、DIC社製)17.62重量部とを添加し、アジターで90秒間撹拌混合し、誘電層用の原料組成物を調製した。次に、原料組成物を図4に示した成形装置30に注入し、保護フィルム31でサンドイッチ状にして搬送しつつ、炉内温度70℃、炉内時間30分間の条件で架橋硬化させ、保護フィルム付きの所定厚みのロール巻シートを得た。その後、70℃に調節した炉で12時間後架橋させ、ポリエーテル系ウレタンエラストマーからなるシートを作製した。得られたウレタンシートを14mm×74mm×厚さ70μmに裁断し、更に、角部の一か所を7mm×7mm×厚さ70μmのサイズで切り落とし、誘電層を作製した。
ここで、上記破断時伸びは、JIS K 6251に準拠して測定した。上記比誘電率は、20mmΦの電極で誘電層を挟み、LCRハイテスタ(日置電機社製、3522-50)を用いて計測周波数1kHzで静電容量を測定した後、電極面積と測定試料の厚さから比誘電率を算出した。
基板成長法により製造した多層カーボンナノチューブである、大陽日酸社製の高配向カーボンナノチューブ(層数4~12層、繊維径10~20nm、繊維長さ150~300μm、炭素純度99.5%)30mgをメチルイソブチルケトン(MIBK)30gに添加し、ジェットミル(ナノジェットパル JN10-SP003、常光社製)を用いて湿式分散処理を施し、10倍に希釈して濃度0.01重量%のカーボンナノチューブ分散液を得た。
上述した(1)誘電層の作製と同様の方法を用いて、ポリエーテル系ウレタンエラストマー製で、14mm×74mm×厚さ50μmの裏側保護層と、14mm×67mm×厚さ50μmの表側保護層とを作製した。
粘着剤(綜研化学社製、SKダイン1720)50重量部に、メチルエチルケトン(MEK)50重量部及び硬化剤(綜研化学社製、L-45)2質量部を添加し、あわとり練太郎(Thinky社製、型番:ARE-310)で混合(2000rpm、120秒)、脱泡(2000rpm、120秒)して混合物を得た。次に、得られた混合物を、表面が離型処理されたPETフィルム(藤森工業社製、50E-0010KF)にアプリケーターを用いて100μmのウエット膜厚で成膜した後、送風式のオーブンを用いて100℃、30分間の条件で硬化させ、硬化後の厚さが25μmの粘着層を作製した。
図5(a)~(d)に示した作製工程を経てセンサ素子を作製した。
まず、上記(3)の工程で作製した裏側保護層25Bの片面(表面)に、離型処理されたPETフィルムに所定の形状の開口部が形成されたマスク(図示せず)を貼り付けた。
上記マスクには、裏側電極層及び裏側配線に相当する開口部が設けられており、開口部のサイズは、裏側電極層に相当する部分が幅10mm×長さ60mm、裏側配線に相当する部分が幅5mm×長さ10mmである。
更に、誘電層21に表側に、裏側電極層22B及び裏側配線23Bの形成と同様の方法を用いて、表側電極層22A及び表側配線23Aを形成した(図5(b)参照)。
更に、表側配線23A及び裏側配線23Bのそれぞれの端部に銅箔を取り付けて、表側接続部24A及び裏側接続部24Bとした(図5(c)参照)。その後、表側接続部24A及び裏側接続部24Bに外部配線となるリード線29を半田で固定した。
最後に、裏側保護層25Bの裏面側に上記(4)で作製した粘着層28をハンドローラーにより貼り付けてセンサ素子222を完成した(図5(d)参照)。
本実施例で作製したセンサ素子Aでは、誘電層21が第1誘電層に、表側電極層22Aが第1電極層に、裏側電極層22Bが第2電極層に、それぞれ相当する。
上記(1)~(5)を経て作製したセンサ素子222をリード線を介してLCRメータ(日置電機社製、LCRハイテスタ3522-50)と接続し、センサ装置とした。
作製したセンサ装置の動作検証として実施例1~4を行った。
図6(a)に示すように、被験者の左手の肘の部分に、粘着層28を介してセンサ素子222を貼り付けた。
その後、センサ素子を貼り付けたまま、左肘の曲げ伸ばしを曲げ量が徐々に大きくなるように行いつつ、そのときの静電容量の変化を測定した。結果を図6(b)に示した。
図6(b)にグラフで示したように、肘関節の曲げ伸ばし運動において、曲げ量が徐々に大きくなるにともない、静電容量も徐々に大きくなることが明らかとなった。
図7(a)に示すように、被験者の左胸に粘着層28を介してセンサ素子222を貼り付けた。
その後、センサ素子を貼り付けたまま、(1)10秒間呼吸を止める、(2)10秒間自然な呼吸を行う、(3)10秒間大きな呼吸を行う、の3種類の動作を行い各動作の際の静電容量を測定した。結果を図7(b)に示した。
図7(b)にグラフで示したように、(1)の動作では静電容量が殆ど変化せず、(2)及び(3)の動作では、それぞれ呼吸の大きさに応じて、静電容量が大きくなることが明らかとなった。更に(2)及び(3)の動作では、10秒間に約2.5回の呼吸が行われたことが推測できた。
図8(a)に示すように、被験者の左頬に粘着層28を介してセンサ素子222を貼り付けた。
その後、センサ素子を貼り付けたまま、日本語の発生音である「あ・い・う・え・お」の発声を行い、そのときの静電容量を測定した。結果を図8(b)に示した。
図8(b)にグラフで示したように、「あ・い・う・え・お」の発声音の種類に応じて静電容量が変化することが明らかとなった。
まず、センサ素子222を被験者に貼り付ける前に、(1)無伸長状態で10秒間の静電容量を測定した。
次に、図9(a)に示すように、被験者の頚動脈(脈のふれるところ)上に粘着層28を介してセンサ素子222を貼り付けた。
その後、(2)平常状態で10秒間の静電容量を測定した。更に、被験者に椅子に座った状態で60秒間足踏み運動(200回/60秒)を行ってもらい、(3)運動(足踏み)後に10秒間息を整えてから10秒間の静電容量を測定した。結果を図9(b)に示した。
また、静電容量の測定と同時に、左手首で10秒間の脈拍を数えたところ、(2)平常時12回、(3)運動後で17回であり、図9(b)の結果と一致していた。
これらのことから、静電容量の変化から心拍数を測定することができることが明らかとなった。
下記の方法で作製したセンサ素子Bを自動平衡ブリッジ回路(LCRメータ)、反転増幅回路、シュミットトリガ発振回路及び半波倍電圧整流回路のいずれかを用いた計測器に接続して静電容量(又は静電容量と相関のある電圧)を測定した。測定結果に基づいて、計測器の種類、及び、センサ素子と計測器との接続方式による測定精度への影響を評価した。
誘電層の厚さを100μmとし、粘着層を形成しなかった以外は、上述したセンサ素子Aの作製と同様にして、センサ素子Bを作製した。
従って、センサ素子Bでは、裏側から表側に向って、裏側保護層(50μm)、裏側電極層、誘電層(100μm)、表側電極層、及び、表側保護層(50μm)がこの順で積層されている。
そして、通常測定の測定値に対する、通常測定の測定値と指を乗せた状態での測定の測定値との差の絶対値の百分率(%)を誤差(%)として算出した。
計測器として、自動平衡ブリッジ回路(LCRメータ:日置電機社製、LCRハイテスタ3522-50)を使用し、測定プローブには4端子プローブ(日置電機製、型番9140)を用いた。これをセンサ素子と接続して静電容量を測定した。
このとき、表側電極層をLo端子に接続し、裏側電極層をHi端子に接続した配線条件を正接続、逆に表側電極層をHi端子に接続し、裏側電極層をLo端子に接続した配線条件を逆接続とした。正接続及び逆接続のそれぞれの配線条件において、通常測定、及び、指を乗せた状態での測定を行った。結果を表1に示した。
計測器として、図10に示したような反転増幅回路300を使用し、これをセンサ素子310と接続して静電容量を測定した。反転増幅回路300において、交流印可装置311の発振周波数は5kHz、帰還キャパシタ313の静電容量は329.2pF、帰還抵抗314の抵抗値は4.7MΩとした。また、図10中、315はBEF(バンドエリミネーションフィルタ)である。
このとき、表側電極層を交流印可装置311に接続し、裏側電極層を演算増幅器312に接続した配線条件を正接続、逆に表側電極層を演算増幅器312に接続し、裏側電極層を交流印可装置311に接続した配線条件を逆接続とした。正接続及び逆接続のそれぞれの配線条件において、通常測定、及び、指を乗せた状態での測定を行った。結果を表1に示した。
計測器として、図11に示したようなシュミットトリガ発振回路400を使用し、これをセンサ素子410と接続してシュミットトリガ412からに出力周波数より静電容量を測定した。シュミットトリガ発振回路400において、可変抵抗413は、通常測定の正接続において発振周波数が5kHzになるように抵抗値を調節した。
このとき、表側電極層を接地し、裏側電極層をシュミットトリガ412側に接続した配線条件を正接続、逆に表側電極層をシュミットトリガ412側に接続し、裏側電極層を接地した配線条件を逆接続とした。正接続及び逆接続のそれぞれの配線条件において、通常測定、及び、指を乗せた状態での測定を行った。結果を表1に示した。
計測器として、図12に示したような半波倍電圧整流回路500を使用し、これをセンサ素子510と接続して出力される電圧を測定した。半波倍電圧整流回路500において、交流印可装置511の発振周波数は5kHz、コンデンサ512の静電容量は0.1μF、抵抗513の抵抗値は470kΩとした。また、ダイオード514、515としては、ショットキーダイオードを使用した。
このとき、表側電極層を交流印可装置511に接続し、裏側電極層をOUTPUT側に接続した配線条件を正接続、逆に表側電極層をOUTPUT側に接続し、裏側電極層を交流印可装置511に接続した配線条件を逆接続とした。正接続及び逆接続のそれぞれの配線条件において、通常測定、及び、指を乗せた状態での測定を行った。結果を表1に示した。
即ち、反転増幅回路及び半波倍電圧整流回路を用いた計測器での測定では、生体に近接する側の電極層を交流印可装置(交流信号を生成する側)に接続することにより測定誤差を低減することができることが明らかとなった。また、シュミットトリガ発振回路を用いた計測器の測定では、生体に近接する側の電極層を接地する(GND側に接続する)ことにより測定誤差を低減することができることが明らかとなった。
2、2′、222 センサ素子
3 計測器
3a、400 シュミットトリガ発振回路
3b F/V変換回路
4 表示器
4a モニター
4b 演算回路
4c 記憶部
11、21 誘電層(第1誘電層)
12A、22A 表側電極層(第1電極層)
12B、22B 裏側電極層(第2電極層)
13A、23A 表側配線
13B、23B 裏側配線
14A、24A 表側接続部
14B、24B 裏側接続部
15A、25A、45A 表側保護層
15B、25B、45B 裏側保護層
18、28 粘着層
41A 第1誘電層
41B 第2誘電層
42A 第1電極層
42B 第2電極層
42C 第3電極層
43A 第1配線
43B 第2配線
43C 第3配線
44A 第1接続部
44B 第2接続部
44C 第3接続部
300 反転増幅回路
500 半波倍電圧整流回路
Claims (7)
- エラストマー組成物からなるシート状の第1誘電層と、カーボンナノチューブを含有する導電性組成物からなり、前記第1誘電層の表面及び裏面のそれぞれに前記第1誘電層を挟んで少なくとも一部が対向するよう形成された第1電極層及び第2電極層とを有し、前記第1電極層及び第2電極層の対向する部分を検出部とし、前記第1誘電層の表裏面の面積が変化するように可逆的に変形するセンサ素子と、
前記検出部における静電容量の変化を計測する計測器とを備え、
生体に貼り付けて使用され、生体表面の変形の追跡に用いられることを特徴とするセンサ装置。 - 前記センサ素子が前記生体表面に直接貼り付けられ、
前記生体表面の変形に基づいて生命活動情報及び/又は生体の運動情報を計測する請求項1に記載のセンサ装置。 - 前記センサ素子が前記生体表面に被覆材を介して貼り付けられ、
前記生体表面の変形に基づいて、生命活動情報、生体の運動情報及び前記被覆材の変形情報のうちの少なくとも1つを計測する請求項1に記載のセンサ装置。 - 前記センサ素子は、更に、第2誘電層及び第3電極層を有し、
前記第2誘電層は、前記第1誘電層の表側に、前記第1誘電層の表面に形成された前記第1電極層を覆うように積層され、
前記第3電極層は、前記第2誘電層を挟んで前記第1電極層と少なくとも一部が対向するように前記第2誘電層の表面に形成されている、請求項1~3の何れかに記載のセンサ装置。 - 計測された静電容量の変化を記憶する記憶部を更に備える請求項1~4にいずれかに記載のセンサ装置。
- 前記計測器は、シュミットトリガ発振回路を用いて静電容量の変化を計測する計測器であり、
前記センサ素子は、裏面側が生体に近接するように貼り付けられ、
前記第1誘電層の裏面に形成された第2電極層は、前記計測器のGND側に接続される、請求項1~5のいずれかに記載のセンサ装置。 - 前記計測器は、反転増幅回路、半波倍電圧整流回路又は自動平衡ブリッジ回路を用いて静電容量の変化を計測する計測器であり、
前記センサ素子は、裏面側が生体に近接するように貼り付けられ、
前記第1誘電層の裏面に形成された第2電極層は、前記計測器の交流信号を生成する側に接続される、請求項1~5のいずれかに記載のセンサ装置。
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2015
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- 2015-03-31 CN CN201910062104.8A patent/CN110031145B/zh active Active
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Also Published As
Publication number | Publication date |
---|---|
EP3130287A4 (en) | 2018-01-03 |
JP6053988B2 (ja) | 2016-12-27 |
JP6230683B2 (ja) | 2017-11-15 |
JP2017047273A (ja) | 2017-03-09 |
US20170020413A1 (en) | 2017-01-26 |
EP3130287B1 (en) | 2022-05-11 |
TWI642408B (zh) | 2018-12-01 |
TWI705797B (zh) | 2020-10-01 |
EP3130287A1 (en) | 2017-02-15 |
TW201902420A (zh) | 2019-01-16 |
EP3868295A1 (en) | 2021-08-25 |
TW201542168A (zh) | 2015-11-16 |
CN110031145B (zh) | 2021-05-04 |
CN106163395A (zh) | 2016-11-23 |
CN106163395B (zh) | 2019-06-18 |
JPWO2015156174A1 (ja) | 2017-04-13 |
CN110031145A (zh) | 2019-07-19 |
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