PULSE WAVE VELOCITY MEASURING DEVICE AND PULSE WAVE VELOCITY MEASUREMENT METHOD

• US 20130079648A1
• Filed: 05/10/2012
• Published: 03/28/2013
• Est. Priority Date: 09/27/2011
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: FUKUZAWA, Hideaki, Hara, Michiko, Fuji, Yoshihiko, Suzuki, Takehiko, Nishimura, Osamu
• Granted Patent: US 9,445,731 B2
• Time in Patent Office: Days
• US Class Current: 600/500
• CPC Class Codes: A61B 2562/0223 Magnetic field sensors
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/02141 Details of apparatus construction, e.g. pump units or housings therefor, cuff pressurising systems, arrangements of fluid conduits or circuits A61B5/02233, A61B5/0235 take precedence
• CPC Class Codes: A61B 5/68335 including release sheets or liners

Abstract

According to one embodiment, a pulse wave velocity measuring device includes a first sensor, a second sensor, a base body and a calculation unit. The first sensor is configured to sense a pulse wave propagating through an interior of a vessel. The second sensor is separated from the first sensor and is configured to sense the pulse wave. The base body is configured to hold the first sensor and the second sensor and regulate a distance between the first sensor and the second sensor. The calculation unit is configured to derive a difference between a time of the sensing of the pulse wave by the first sensor and a time of the sensing of the pulse wave by the second sensor.

Claims

1. A pulse wave velocity measuring device, comprising:

a first sensor configured to sense a pulse wave propagating through an interior of a vessel;

a second sensor separated from the first sensor and configured to sense the pulse wave;

a base body configured to hold the first sensor and the second sensor and regulate a distance between the first sensor and the second sensor; and

a calculation unit configured to derive a difference between a time of the sensing of the pulse wave by the first sensor and a time of the sensing of the pulse wave by the second sensor.

2. The device according to claim 1, wherein the first sensor and the second sensor include a magnetic material.

3. The device according to claim 1, wherein

the first sensor includes a first ferromagnetic layer, a second ferromagnetic layer, and a first intermediate layer provided between the first ferromagnetic layer and the second ferromagnetic layer, the first intermediate layer being nonmagnetic, and

the second sensor includes a third ferromagnetic layer, a fourth ferromagnetic layer, and a second intermediate layer provided between the third ferromagnetic layer and the fourth ferromagnetic layer, the second intermediate layer being nonmagnetic.

4. The device according to claim 3, wherein the first intermediate layer and the second intermediate layer include at least one of Cu, Au and Ag, and a thickness of the first intermediate layer and a thickness of the second intermediate layer are not less than 1 nanometer and not more than 7 nanometers.

5. The device according to claim 3, wherein the first intermediate layer and the second intermediate layer include at least one of a magnesium oxide, aluminum oxide, titanium oxide and zinc oxide, and a thickness of the first intermediate layer and a thickness of the second intermediate layer are not less than 0.6 nanometers and not more than 2.5 nanometers.

6. The device according to claim 1, wherein electrical resistances of the first sensor and the second sensor change due to a change of a magnetization direction due to an inverse magnetostrictive effect corresponding to stress applied to the first sensor and the second sensor by the pulse wave.

7. The device according to claim 1, wherein the first sensor and the second sensor further include diaphragms.

8. The device according to claim 1, wherein the base body includes an adhesive layer.

9. The device according to claim 1, wherein the calculation unit is provided on the base body.

10. The device according to claim 1, wherein the deriving of the difference by the calculation unit includes autocorrelation signal processing of a signal of the sensing of the pulse wave by the first sensor and a signal of the sensing of the pulse wave by the second sensor.

11. The device according to claim 1, wherein the base body includes at least one of a silicon substrate and a printed circuit board.

12. The device according to claim 1, wherein the base body includes a plastic substrate.

13. The device according to claim 1, wherein the base body is flexible.

14. The device according to claim 1, wherein the distance is not less than 1 mm and not more than 5 cm.

15. The device according to claim 1, wherein the distance is not less than 5 mm and not more than 2 cm.

16. The device according to claim 1, wherein a size of the first sensor and the second sensor is not less than 100 nm×

100 nm and not more than 10 μ

m×

10 μ

m.

17. A pulse wave velocity measurement method, comprising:

sensing a pulse wave propagating through an interior of a vessel of a sense object by causing a measurement sensor to contact the sense object, the measurement sensor including a base body, a first sensor, and a second sensor, the pulse wave being sensed using the first sensor and the second sensor, the first sensor being held by the base body, the second sensor being held by the base body to be separated from the first sensor, a distance between the first sensor and the second sensor being regulated by the base body; and

deriving a pulse wave velocity based on a difference between a time of the sensing of the pulse wave by the first sensor and a time of the sensing of the pulse wave by the second sensor.

18. The method according to claim 17, wherein the measurement sensor is disposed on a skin in contact with the skin.

19. The method according to claim 17, further comprising disposing the measurement sensor on a position of at least one of a medial bicipital groove (brachial artery), between a flexor carpi radialis tendon and a brachioradialis tendon at an outer lower end of a forearm (radial artery), between a flexor carpi ulnaris tendon and a superficial digital flexor tendon at an inner lower end of a forearm (ulnar artery), an ulnar side of an extensor pollicis longus tendon (first dorsal metacarpal artery), an axilla (axillary artery), a femoral triangle (femoral artery), an outer side of a tibialis anterior tendon at a lower portion of an anterior surface of a leg (anterior tibial artery), a posterior lower portion of a medial malleolus (posterior tibial artery), an outer side of an extensor pollicis longus tendon (dorsalis pedis artery), a carotid artery triangle (common carotid artery), in front of a masseter insertion (facial artery), behind a sternocleidomastoid insertion between a trapezius muscle origin and the sternocleidomastoid insertion (lateral occipital artery), and in front of an external acoustic opening (superficial temporal artery).

20. The method according to claim 17, wherein the distance is not less than 1 mm and not more than 5 cm.