Electrocardiographic detection device

Abstract

In this electrocardiographic detection device, an occupant grips a rim part of a steering wheel and comes into contact with a left electrode and a right electrode of the rim part. The detection unit then outputs an electrocardiographic waveform of the occupant. The left electrode and the right electrode are provided on an upper portion of the rim part on the upper side and the lower side of the steering wheel. Thus, the occupant comes into contact with the rim part due to the load of their arm, and the occupant can therefore stably come into contact with the left electrode and the right electrode even when a vehicle is vibrating.

Description

electrocardiogram detector

[0001] The present invention relates to an electrocardiogram detection device for detecting an electrocardiogram waveform of a driver gripping a contact portion of a steering wheel.

[0002] In the grip detection device described in JP 2016-203660 A, a first electrode and a second electrode are provided at grip portions on the left and right sides of a vehicle steering wheel, respectively, and a driver grips the grip portions of the steering wheel to contact the first electrode and the second electrode. Furthermore, a heartbeat detection unit is connected to the first electrode and the second electrode, and the heartbeat detection unit detects the heartbeat of the driver who is in contact with the first electrode and the second electrode.

[0003] Here, in such a grip detection device, it is preferable that the driver can stably contact the first electrode and the second electrode even when the vehicle is vibrating.

[0004] In consideration of the above, an object of the present invention is to provide an electrocardiogram detecting device that allows an occupant to stably contact the left and right electrodes even when the vehicle is vibrating.

[0005] The electrocardiogram detection device of a first aspect of the present invention comprises a steering wheel having a contact portion that is steered by an occupant gripping and operating the contact portion to steer the vehicle; a left electrode provided on the left, upper, and lower sides of the steering wheel above the contact portion and that is contacted by an occupant gripping the contact portion; a right electrode provided on the right, upper, and lower sides of the steering wheel above the contact portion and that is contacted by an occupant gripping the contact portion; and a detection unit connected to the left and right electrodes and that detects the electrocardiogram waveform of the occupant contacting the left and right electrodes.

[0006] The electrocardiogram detection device of a second aspect of the present invention is the electrocardiogram detection device of the first aspect of the present invention, and further includes a DRL electrode that is provided in a portion of the contact portion different from the left electrode and the right electrode, and that comes into contact with an occupant gripping the contact portion, and in-phase signal noise that has entered the left electrode and the right electrode via the occupant is inverted and fed back to the occupant.

[0007] An electrocardiogram detection device according to a third aspect of the present invention is the electrocardiogram detection device according to the second aspect of the present invention, wherein the DRL electrode is provided on the opposite side of the contact portion to the left electrode or the right electrode.

[0008] The fourth aspect of the electrocardiogram detection device of the present invention is an electrocardiogram detection device of any one of the first to third aspects of the present invention, in which at least one of the left electrode and the right electrode is provided in a front portion of the contact portion at the middle of the steering wheel in the vertical direction.

[0009] The electrocardiogram detection device of the fifth aspect of the present invention is an electrocardiogram detection device of any one of the first to fourth aspects of the present invention, in which at least one of the left electrode and the right electrode is provided in an upper part of the contact portion, which is a connection portion that connects the central portion and the peripheral portion of the steering wheel.

[0010] In the electrocardiogram detection device of the first aspect of the present invention, a vehicle is steered by an occupant gripping a contact portion of the steering wheel and operating the steering wheel. A left electrode and a right electrode are provided on the contact portions on the left and right sides of the steering wheel, respectively, and the occupant gripping the contact portions contacts the left electrode and the right electrode. Furthermore, a detection unit is connected to the left electrode and the right electrode, and the detection unit detects the electrocardiogram waveform of the occupant who is in contact with the left electrode and the right electrode.

[0011] Here, the left and right electrodes are provided above the contact portions on the upper and lower sides of the steering wheel, so that when an occupant grips the contact portion on the upper side of the steering wheel or the contact portion on the lower side of the steering wheel, the occupant's hands come into contact with the contact portions due to the weight of their arms, allowing the occupant to stably contact the left and right electrodes even when the vehicle vibrates.

[0012] In the electrocardiogram detection device of the second aspect of the present invention, the DRL electrodes are provided at positions different from the left and right electrodes of the contact portion, and an occupant gripping the contact portion comes into contact with the DRL electrodes. Furthermore, common-mode signal noise that has entered the left and right electrodes via the occupant is inverted and fed back to the occupant from the DRL electrodes. This reduces the common-mode signal noise that has entered the left and right electrodes via the occupant.

[0013] In the electrocardiogram detection device according to the third aspect of the present invention, the DRL electrode is provided on the side of the contact portion opposite the left or right electrode, so that an occupant gripping the contact portion can easily come into contact with the left or right electrode and the DRL electrode.

[0014] In the electrocardiogram detection device of the fourth aspect of the present invention, at least one of the left electrode and the right electrode is provided in a front portion of the contact portion at the vertical middle of the steering wheel, so that an occupant gripping the contact portion at the vertical middle of the steering wheel can easily contact at least one of the left electrode and the right electrode.

[0015] In the electrocardiogram detection device of the fifth aspect of the present invention, at least one of the left electrode and the right electrode is provided on an upper portion of a contact portion which is a connection portion that connects the central portion and the peripheral portion of the steering wheel, so that when an occupant grips the connection portion, the occupant can bring their hand into contact with at least one of the left electrode and the right electrode due to the weight of their arm.

[0016] FIG. 1 is a diagram showing an electrocardiogram detection device according to a first embodiment of the present invention; FIG. 2 is a front view showing an upper portion of a steering wheel in the first embodiment of the present invention, as seen from the front; FIG. 3 is a front view showing a lower portion of a steering wheel in the first embodiment of the present invention, as seen from the front; FIG. 4 is an electrocardiogram waveform detected by the electrocardiogram detection device according to the first embodiment of the present invention, showing a case where an occupant grips the upper portion of the steering wheel; FIG. 5 is an electrocardiogram waveform detected by the electrocardiogram detection device according to the first embodiment of the present invention, showing a case where an occupant grips the lower portion of the steering wheel; FIG. 6 is an electrocardiogram waveform detected by an electrocardiogram detection device of a comparative example, showing a case where an occupant grips the upper portion of the steering wheel; FIG. 7 is an electrocardiogram waveform detected by an electrocardiogram detection device of a comparative example, showing a case where an occupant grips the lower portion of the steering wheel; FIG. 8 is a front view showing a steering wheel of an electrocardiogram detection device according to a second embodiment of the present invention, as seen from the front; FIG. 9 is a front view showing a steering wheel of an electrocardiogram detection device according to a third embodiment of the present invention, as seen from the front; FIG. 10 is a front view showing a steering wheel of an electrocardiogram detection device according to a fourth embodiment of the present invention, as seen from the front; FIG. 11 is a front view showing a steering wheel of an electrocardiogram detection device according to a fifth embodiment of the present invention, as seen from the front.

[0017] 1 shows an electrocardiogram detection device 10 according to a first embodiment of the present invention, and in FIG. 1, a front view of a steering wheel 12 of the electrocardiogram detection device 10 is shown. In the drawing, the arrow UP indicates the top of the steering wheel 12, and the arrow RH indicates the right side of the steering wheel 12.

[0018] The electrocardiogram detection device 10 according to this embodiment is installed in a vehicle. As shown in Fig. 1, the electrocardiogram detection device 10 is provided on a steering wheel 12 of the vehicle, and the front, upper, and right sides of the steering wheel 12 are directed obliquely upward and rearward, obliquely upward and forward, and rightward, respectively. The steering wheel 12 faces the front side of the driver's seat of the vehicle, and is disposed in front of an occupant (driver, human body) seated in the driver's seat.

[0019] The central portion of the steering wheel 12 is a boss portion 12A, and the peripheral portion of the steering wheel 12 is a rim portion 12B that is annular in front view and has a circular cross section and that forms a contact portion. Three spoke portions 12C are provided between the boss portion 12A and the rim portion 12B as connecting portions that form the contact portion, and the spoke portions 12C extend leftward, rightward, and downward from the boss portion 12A and are connected to the rim portion 12B.

[0020] The boss portion 12A is fixed to the rear end (upper end) of a cylindrical steering shaft 14 serving as a support member for the vehicle, and the steering shaft 14 is disposed coaxially with the rim portion 12B. The steering wheel 12 is supported by the steering shaft 14 so as to be rotatable integrally with the steering shaft 14, and when an occupant grips the rim portion 12B in particular and rotates the steering wheel 12 in the circumferential direction, the steering shaft 14 rotates about the central axis, thereby steering the vehicle.

[0021] A left electrode 16 (left detection electrode) and a right electrode 18 (right detection electrode) are provided on the left and right sides of the steering wheel 12, and the left electrode 16 and right electrode 18 are arranged on the circumferential surface of the rim portion 12B. On the upper side of the steering wheel 12, the left electrode 16 and right electrode 18 are arranged on the upper portion (outer peripheral portion) of the rim portion 12B, and the left electrode 16 and right electrode 18 on the upper side of the steering wheel 12 extend from near the upper end of the rim portion 12B to the connection portions with the left and right spoke portions 12C of the rim portion 12B, respectively. On the lower side of the steering wheel 12, the left electrode 16 and right electrode 18 are arranged on the upper portion (inner peripheral portion) of the rim portion 12B, and the left electrode 16 and right electrode 18 on the lower side of the steering wheel 12 extend from the left and right ends of the connection portions with the lower spoke portions 12C of the rim portion 12B to the lower ends of the connection portions with the left and right spoke portions 12C of the rim portion 12B, respectively.

[0022] At the vertical center of the steering wheel 12, the left electrode 16 and the right electrode 18 are respectively formed as a left conductive portion 16A and a right conductive portion 18A, with the left conductive portion 16A extending in the front portion of the rim portion 12B to provide electrical continuity between the left electrodes 16 on the upper and lower sides of the steering wheel 12, and the right conductive portion 18A extending in the front portion of the rim portion 12B to provide electrical continuity between the right electrodes 18 on the upper and lower sides of the steering wheel 12.

[0023] The steering wheel 12 is provided with a DRL electrode 20 (Driven Right Leg electrode), which is disposed on the circumferential surface of the rim portion 12B. On the upper side of the steering wheel 12, the DRL electrode 20 is disposed on the lower portion (inner peripheral portion) of the rim portion 12B, and the upper DRL electrode 20 of the steering wheel 12 extends from near the upper end of the rim portion 12B to the upper ends of the connection portions with the left and right spoke portions 12C of the rim portion 12B on the left and right sides of the steering wheel 12. On the lower side of the steering wheel 12, the DRL electrode 20 is disposed on the lower portion (outer peripheral portion) of the rim portion 12B, and the lower DRL electrode 20 of the steering wheel 12 extends from the left and right ends of the connection portions with the lower spoke portions 12C of the rim portion 12B to the lower ends of the connection portions with the left and right spoke portions 12C of the rim portion 12B on the left and right sides of the steering wheel 12.

[0024] At the vertical center of the steering wheel 12, the DRL electrode 20 is formed as a left intermediate portion 20A and a right intermediate portion 20B on the left and right sides of the steering wheel 12, respectively. The left intermediate portion 20A extends from the front portion of the rim portion 12B, providing electrical continuity between the DRL electrodes 20 on the upper and left sides of the steering wheel 12 and the DRL electrodes 20 on the lower and left sides of the steering wheel 12, and the left intermediate portion 20A is insulated from the left conductive portion 16A of the left electrode 16. The right intermediate portion 20B extends from the front portion of the rim portion 12B, providing electrical continuity between the DRL electrodes 20 on the upper and right sides of the steering wheel 12 and the DRL electrodes 20 on the lower and right sides of the steering wheel 12, and the right intermediate portion 20B is insulated from the right conductive portion 18A of the right electrode 18.

[0025] When the occupant's hands 22 grip the rim portion 12B of the steering wheel 12 (see Figures 2A and 2B), the occupant's left hand 22 typically contacts the left electrode 16 and DRL electrode 20 on the left side of the steering wheel 12, and the occupant's right hand 22 typically contacts the right electrode 18 and DRL electrode 20 on the right side of the steering wheel 12.

[0026] A detection unit 24 is connected to the left electrode 16 , the right electrode 18 and the DRL electrode 20 of the steering wheel 12 .

[0027] The detection unit 24 is provided with a differential amplifier 26 (detection circuit). The left electrode 16 of the steering wheel 12 is connected to a non-inverting input terminal (+) of the differential amplifier 26 via a buffer amplifier 28A, and the right electrode 18 of the steering wheel 12 is connected to an inverting input terminal (-) of the differential amplifier 26 via a buffer amplifier 28B, and a differential voltage between the left electrode 16 and the right electrode 18 is output from the differential amplifier 26. A processing circuit 30 is connected to the output terminal of the differential amplifier 26, and the processing circuit 30 performs filtering, amplification, and AD conversion on the output signal from the differential amplifier 26, and outputs the electrocardiographic waveform (electrocardiographic signal) of the occupant as the detection output of the detection unit 24.

[0028] The differential amplifier 26 is connected to the input side of a DRL amplifier 32 (Driven Right Leg amplifier), and the left and right DRL electrodes 20 of the steering wheel 12 are connected to the output side of the DRL amplifier 32 in a mutually conductive state. Therefore, common-mode signal noise that enters the left electrode 16 and the right electrode 18 via the occupant is inverted and amplified in the DRL amplifier 32 and fed back to the occupant via the DRL electrodes 20.

[0029] Furthermore, as described above, by providing the buffer amplifiers 28A and 28B between the left electrode 16 and the right electrode 18 and the differential amplifier 26, respectively, a measure is taken to prevent a decrease in gain from the occupant to the differential amplifier 26. This prevents deterioration of the electrocardiogram signal output from the detector 24 and also prevents common-mode signal noise from entering the detection output of the detector 24 due to an imbalance between the left electrode 16 and the right electrode 18.

[0030] Next, the operation of this embodiment will be described.

[0031] In the electrocardiogram detection device 10 configured as described above, when the occupant's hands 22 grip the rim portion 12B of the steering wheel 12, the left hand 22 typically contacts the left electrode 16 and DRL electrode 20 on the left side of the steering wheel 12, and the right hand 22 typically contacts the right electrode 18 and DRL electrode 20 on the right side of the steering wheel 12. The detection unit 24 then outputs the occupant's electrocardiogram waveform based on the differential voltage between the left electrode 16 and the right electrode 18 output from the differential amplifier 26.

[0032] When the occupant's hands 22 grip the steering wheel 12 , the occupant tends to place the weight of their arms on the steering wheel 12 .

[0033] Here, a left electrode 16 and a right electrode 18 are provided on the upper portion of the rim portion 12B on the upper and lower sides of the steering wheel 12.

[0034] Therefore, when the occupant's hand 22 grips the rim portion 12B on the upper side of the steering wheel 12, the occupant's arm weight brings the hand 22 into contact with the rim portion 12B, and even during vibrations caused by the vehicle traveling, the portion 22A of the occupant's palm near the four fingers (four fingers other than the thumb) can stably contact the left electrode 16 and the right electrode 18 (see FIG. 2A ). This makes it possible to prevent noise caused by vehicle vibrations from being introduced into the occupant's electrocardiogram waveform output by the detection unit 24, and the occupant's pulse can be clearly detected from the occupant's electrocardiogram waveform (see FIG. 3A ).

[0035] Furthermore, when the occupant's hand 22 grips the rim portion 12B on the underside of the steering wheel 12, the weight of the occupant's arm brings the hand 22 into contact with the rim portion 12B, which allows the thumb portion 22B of the occupant's palm to stably contact the left electrode 16 and the right electrode 18 even during vibrations caused by the vehicle moving (see FIG. 2B). This makes it possible to prevent noise caused by vehicle vibrations from being introduced into the occupant's electrocardiogram waveform output by the detection unit 24, and the occupant's pulse can be clearly detected from the occupant's electrocardiogram waveform (see FIG. 3B).

[0036] Additionally, the DRL electrode 20 is provided on a portion of the rim portion 12B different from the left electrode 16 and right electrode 18, and as described above, an occupant gripping the rim portion 12B comes into contact with the DRL electrode 20. Furthermore, common-mode signal noise that enters the left electrode 16 and right electrode 18 via the occupant is inverted and amplified by the DRL amplifier 32 of the detection unit 24 and fed back to the occupant via the DRL electrode 20. This reduces common-mode signal noise that enters the left electrode 16 and right electrode 18 via the occupant.

[0037] Furthermore, a DRL electrode 20 is provided on the opposite side of the rim portion 12B from the left electrode 16 and the right electrode 18 (opposite side in the circumferential direction of the rim portion 12B (direction around the steering wheel 12)). This allows an occupant gripping the rim portion 12B to easily come into contact with the left electrode 16, the right electrode 18, and the DRL electrode 20.

[0038] Furthermore, the left conductive portion 16A of the left electrode 16 and the right conductive portion 18A of the right electrode 18 are disposed in front of the rim portion 12B at the vertical center of the steering wheel 12. Therefore, when an occupant's hand 22 grips the rim portion 12B at the vertical center of the steering wheel 12, the occupant can easily bring the hand 22 into contact with the left electrode 16 (left conductive portion 16A) and the right electrode 18 (left conductive portion 16A). Furthermore, by bringing the hand 22 into contact with the rim portion 12B due to the weight of the occupant's arm, at least one of the thumb and the thumb-proximal portion 22B of the palm of the occupant's hand 22 can stably contact the left electrode 16 (left conductive portion 16A) and the right electrode 18 (left conductive portion 16A) even during vibrations caused by the vehicle traveling.

[0039] (Comparative Example) In the electrocardiogram detection device of the comparative example, a DRL electrode 20 and a left electrode 16 are arranged at the positions of the left electrode 16 and the DRL electrode 20 on the left side of the steering wheel 12 in the first embodiment, respectively, and a DRL electrode 20 and a right electrode 18 are arranged at the positions of the right electrode 18 and the DRL electrode 20 on the right side of the steering wheel 12 in the first embodiment, respectively.

[0040] In the electrocardiogram detection device of the comparative example, when an occupant's hand 22 grips the rim portion 12B on the upper side of the steering wheel 12, the occupant's hand 22 cannot stably contact the left electrode 16 and the right electrode 18 when the vehicle vibrates while traveling. As a result, it is not possible to prevent noise caused by vehicle vibration from being introduced into the occupant's electrocardiogram waveform output by the detection unit 24, and the occupant's pulse cannot be clearly detected from the occupant's electrocardiogram waveform (see FIG. 3C ).

[0041] Furthermore, when the occupant's hands 22 grip the rim portion 12B on the underside of the steering wheel 12, vibrations caused by the vehicle traveling prevent the occupant's hands 22 from stably contacting the left electrode 16 and the right electrode 18. As a result, noise caused by vehicle vibrations cannot be prevented from entering the occupant's electrocardiogram waveform output by the detection unit 24, and the occupant's pulse cannot be clearly detected from the occupant's electrocardiogram waveform (see FIG. 3D).

[0042] 1, in an electrocardiogram detection device 40 of this modification, a left additional portion 16B (see two-dot chain line in FIG. 1) of the left electrode 16 is provided in an upper portion near the rim portion 12B of the left spoke portion 12C of the steering wheel 12 in the first embodiment, and the left additional portion 16B is electrically connected to other portions of the left electrode 16. Furthermore, a right additional portion 18B (see two-dot chain line in FIG. 1) of the right electrode 18 is provided in an upper portion near the rim portion 12B of the right spoke portion 12C of the steering wheel 12 in the first embodiment, and the right additional portion 18B is electrically connected to other portions of the right electrode 18.

[0043] Here, this modified example can also achieve the same functions and effects as the first embodiment.

[0044] Furthermore, the left additional portion 16B of the left electrode 16 and the right additional portion 18B of the right electrode 18 are disposed on the left side and above the left spoke portion 12C at the vertical center of the steering wheel 12. Therefore, when an occupant's hand 22 grips the rim portion 12B and the spoke portion 12C at the vertical center of the steering wheel 12, the occupant can easily bring the thumb of the hand 22 into contact with the left electrode 16 (left additional portion 16B) and the right electrode 18 (right additional portion 18B). Moreover, by bringing the thumb of the hand 22 into contact with the spoke portion 12C due to the weight of the occupant's arm, the thumb of the occupant's hand 22 can stably contact the left electrode 16 (left additional portion 16B) and the right electrode 18 (right additional portion 18B) even during vibrations caused by the vehicle traveling.

[0045] Second Embodiment FIG. 4A shows a front view of a steering wheel 12 of an electrocardiogram detection device 50 according to a second embodiment of the present invention.

[0046] The electrocardiogram detection device 50 according to this embodiment has almost the same configuration as that of the first embodiment, but differs in the following respects.

[0047] As shown in FIG. 4A, in an electrocardiogram detection device 50 according to this embodiment, the steering wheel 12 does not have a lower spoke portion 12C.

[0048] The lower end of the rim portion 12B of the steering wheel 12 extends in the left-right direction, and the rim portion 12B is D-shaped when viewed from the front.

[0049] The left electrode 16 and right electrode 18 on the underside of the steering wheel 12 extend from near the center of the lower end of the rim portion 12B to the lower ends of the connecting portions with the left and right spoke portions 12C of the rim portion 12B. The DRL electrodes 20 on the underside of the steering wheel 12 extend from near the center of the lower end of the steering wheel 12 to the lower ends of the connecting portions with the left and right spoke portions 12C of the rim portion 12B on the left and right sides of the steering wheel 12.

[0050] Here, this embodiment can also achieve the same functions and effects as the first embodiment.

[0051] Third Embodiment FIG. 4B shows a front view of the steering wheel 12 of an electrocardiogram detection device 60 according to a third embodiment of the present invention.

[0052] The electrocardiogram detection device 60 according to this embodiment has almost the same configuration as that of the first embodiment, but differs in the following respects.

[0053] 4B , in the electrocardiogram detection device 60 according to this embodiment, the rim portion 12B of the steering wheel 12 does not have an upper end portion, and the rim portion 12B is generally C-shaped in a front view. The lower end portion of the rim portion 12B extends in the left-right direction.

[0054] The left electrode 16 and right electrode 18 on the upper side of the steering wheel 12 extend from the upper end of the rim portion 12B to the connection portions with the left and right spoke portions 12C of the rim portion 12B, respectively. The DRL electrodes 20 on the upper side of the steering wheel 12 extend from the upper end of the rim portion 12B to the upper ends of the connection portions with the left and right spoke portions 12C of the rim portion 12B, respectively, on the left and right sides of the steering wheel 12.

[0055] Here, this embodiment can also achieve the same functions and effects as the first embodiment.

[0056] In the second and third embodiments, as in the above-described modified examples, a left additional portion 16B of the left electrode 16 and a right additional portion 18B of the right electrode 18 may be provided on the left side of the steering wheel 12 and the upper portion of the left spoke portion 12C, respectively.

[0057] Fourth Embodiment FIG. 5A shows a front view of a steering wheel 12 of an electrocardiogram detection device 70 according to a fourth embodiment of the present invention.

[0058] The electrocardiogram detection device 70 according to this embodiment has almost the same configuration as that of the first embodiment, but differs in the following respects.

[0059] As shown in FIG. 5A, in an electrocardiogram detection device 70 according to this embodiment, the steering wheel 12 is not provided with spokes 12C.

[0060] The rim portions 12B of the steering wheel 12 are U-shaped in front view on the left and right sides of the steering wheel 12, and the upper ends of the rim portions 12B are connected to the left and right sides of the boss portion 12A on the left and right sides of the steering wheel 12, respectively, and the lower ends are connected to each other, with the connecting portion being connected to the underside of the boss portion 12A. Furthermore, the left and right ends of the rim portions 12B are inclined downward, inclining outward in the left-right direction of the steering wheel 12.

[0061] On the upper side of the steering wheel 12, the left electrode 16 and the right electrode 18 are arranged on the upper portion (outer peripheral portion) of the rim portion 12B, and the left electrode 16 and the right electrode 18 on the upper side of the steering wheel 12 extend from the upper end portions of the left and right sides of the rim portion 12B to the left and right ends, respectively. On the lower side of the steering wheel 12, the left electrode 16 and the right electrode 18 are arranged on the upper portion (inner peripheral portion) of the rim portion 12B, and the left electrode 16 and the right electrode 18 on the lower side of the steering wheel 12 extend to the lower ends of the left and right sides of the rim portion 12B, respectively.

[0062] On the upper side of the steering wheel 12, the DRL electrode 20 is disposed in the lower portion (inner peripheral portion) of the rim portion 12B, and the DRL electrode 20 on the upper side of the steering wheel 12 extends from the upper end portions of the left and right sides of the rim portion 12B to the left and right ends, respectively, on the left and right sides of the steering wheel 12. On the lower side of the steering wheel 12, the DRL electrode 20 is disposed in the lower portion (outer peripheral portion) of the rim portion 12B, and the DRL electrode 20 on the lower side of the steering wheel 12 extends to the lower ends of the left and right sides of the rim portion 12B, respectively, on the left and right sides of the steering wheel 12.

[0063] Here, this embodiment can also achieve the same functions and effects as the first embodiment.

[0064] Fifth Embodiment FIG. 5B shows a front view of the steering wheel 12 of an electrocardiogram detection device 80 according to a fifth embodiment of the present invention.

[0065] The electrocardiogram detection device 80 according to this embodiment has almost the same configuration as that of the first embodiment, but differs in the following respects.

[0066] As shown in FIG. 5B, in an electrocardiogram detection device 80 according to this embodiment, the steering wheel 12 is not provided with spokes 12C.

[0067] The rim portions 12B of the steering wheel 12 are U-shaped in front view on the left and right sides of the steering wheel 12, and the lower ends of the rim portions 12B are connected to the left and right sides of the boss portion 12A on the left and right sides of the steering wheel 12, respectively, and the upper ends are connected to each other, with the connecting portion being connected to the upper side of the boss portion 12A. Furthermore, the left and right ends of the rim portions 12B are inclined inward in the left-right direction of the steering wheel 12 as they extend downward.

[0068] On the upper side of the steering wheel 12, the left electrode 16 and the right electrode 18 are arranged in the upper portion (outer peripheral portion) of the rim portion 12B, and the left electrode 16 and the right electrode 18 on the upper side of the steering wheel 12 extend from the upper ends of the left and right sides of the rim portion 12B, respectively. On the lower side of the steering wheel 12, the left electrode 16 and the right electrode 18 are arranged in the upper portion (inner peripheral portion) of the rim portion 12B, and the left electrode 16 and the right electrode 18 on the lower side of the steering wheel 12 extend from the lower ends of the left and right sides of the rim portion 12B to the left and right ends, respectively.

[0069] On the upper side of the steering wheel 12, the DRL electrode 20 is disposed in the lower portion (inner peripheral portion) of the rim portion 12B, and the DRL electrode 20 on the upper side of the steering wheel 12 extends from the upper end portions of the left and right sides of the rim portion 12B on the left and right sides of the steering wheel 12, respectively. On the lower side of the steering wheel 12, the DRL electrode 20 is disposed in the lower portion (outer peripheral portion) of the rim portion 12B, and the DRL electrode 20 on the lower side of the steering wheel 12 extends from the lower end portions of the left and right sides of the rim portion 12B to the left and right ends, respectively, on the left and right sides of the steering wheel 12.

[0070] Here, this embodiment can also achieve the same functions and effects as the first embodiment.

[0071] In the first to fifth embodiments, the DRL electrodes 20 are separated into the left and right sides of the steering wheel 12. However, the DRL electrodes 20 may be integrated into one on the left and right sides of the steering wheel 12.

[0072] The disclosure of Japanese Patent Application No. 2023-147123, filed on September 11, 2023, is incorporated herein by reference in its entirety.

[0073] 10... electrocardiogram detection device, 12... steering wheel, 12A... boss portion (central portion), 12B... rim portion (circumferential portion, contact portion), 12C... spoke portion (connection portion, contact portion), 16... left electrode, 18... right electrode, 20... DRL electrode, 24... detection portion, 40... electrocardiogram detection device, 50... electrocardiogram detection device, 60... electrocardiogram detection device, 70... electrocardiogram detection device, 80... electrocardiogram detection device

Claims

1. An electrocardiogram detection device comprising: a steering wheel having a contact portion, the vehicle being steered when an occupant grasps and operates the contact portion; a left electrode provided on the left side, upper and lower sides of the steering wheel, above the contact portion, and contacted by an occupant grasping the contact portion; a right electrode provided on the right side, upper and lower sides of the steering wheel, above the contact portion, and contacted by an occupant grasping the contact portion; and a detection portion connected to the left and right electrodes, for detecting the electrocardiogram waveform of the occupant contacting the left and right electrodes.

2. An electrocardiogram detection device as described in claim 1, further comprising a DRL electrode which is provided at a portion of the contact portion different from the left electrode and the right electrode, and which is contacted by an occupant gripping the contact portion, and which inverts common-mode signal noise which has entered the left electrode and the right electrode via the occupant and is fed back to the occupant.

3. An electrocardiogram detection device as claimed in claim 2, wherein the DRL electrode is provided on the opposite side of the contact portion to the left electrode or the right electrode.

4. An electrocardiogram detection device according to claim 2 or 3, wherein the DRL electrodes are provided over the entire circumferential position of the steering wheel where the left electrode or the right electrode is provided.

5. An electrocardiogram detection device as described in any one of claims 2 to 4, wherein the DRL electrode is provided on an inner circumferential portion of the contact portion on the upper side of the steering wheel, and the DRL electrode is provided on an outer circumferential portion of the contact portion on the lower side of the steering wheel.

6. An electrocardiogram detection device as claimed in claim 2 or 3, wherein the DRL electrode is provided at a front portion of the contact portion at the vertical middle of the steering wheel.

7. An electrocardiogram detection device as claimed in any one of claims 1 to 6, wherein at least one of the left electrode and the right electrode is provided in a front portion of the contact portion at the vertical middle of the steering wheel.

8. An electrocardiogram detection device as claimed in any one of claims 1 to 7, wherein at least one of the left electrode and the right electrode is provided on the upper part of the contact portion, which is a connection portion connecting the central portion and the peripheral portion of the steering wheel.

9. An electrocardiogram detection device as described in any one of claims 1 to 8, wherein the left electrode and the right electrode are provided on the outer circumferential portion of the contact portion on the upper side of the steering wheel, and the left electrode and the right electrode are provided on the inner circumferential portion of the contact portion on the lower side of the steering wheel.

10. An electrocardiogram detection device according to any one of claims 1 to 9, wherein the left electrode and the right electrode extend in the circumferential direction of the steering wheel.

Images