Vital signal detecting apparatus

• US 6,608,562 B1
• Filed: 08/30/2000
• Issued: 08/19/2003
• Est. Priority Date: 08/31/1999
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ito, Masahiko, Yamada, Seiichi, Kodama, Satoru, Koumura, Tsukasa, Hasegawa, Masao, Takeuchi, Satoshi, Nanba, Shinji, Kimura, Teiyuu, Ohsaki, Rie
• Primary Examiner(s): Lee, Benjamin C.
• Application Number:
  US09/651,078
• Time in Patent Office: 1,084 Days
• Field of Search: 340/573.1, 340/573.4, 340/539, 600/502, 600/503, 600/344, 600/300, 600/309, 600/485, 600/500, 600/508, 600/310, 600/549, 600/323, 600/521, 128/903, 988/411
• US Class Current: 340/573.1
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A vital signal detecting apparatus comprises an attachable device to be attached to a finger, a sensor having a light-emitting device and a light-receiving device, and a transmitting circuit for transmitting a signal waveform as a pulse wave from the sensor to a pulse wave monitoring unit. The pulse wave detecting unit also has an attachment detecting circuit for detecting whether or not the attachable device is in an attached state by comparing a signal waveform obtained when the light-emitting device is on with a signal waveform obtained when the light-emitting device is off and an operation control circuit for controlling the operation of the sensor, the transmitting circuit and the attachment detecting circuit. Preferably, the light-transmitting plate is disposed above the light-emitting device and the light-receiving device to pass light therethrough, and the light transmitting plate may be an IR-cut filter capable of blocking light of wavelengths greater than 700 nm.

Claims

1. A vital signal detecting apparatus, comprising:

an attachable device to be attached to a human body;

vital signal detecting means, disposed on the attachable device on a side thereof to be attached to the body, for detecting a vital signal of the body the vital signal detecting means including a light-emitting device for emitting light through skin into the body and a light-receiving device for receiving light returning from inside the body and outputting a signal corresponding to the amount of light received;

attachment state detecting means for detecting a state of attachment/detachment of the attachable device to the body for detecting the state of attachment/detachment of the attachable device to the body on the basis of a signal outputted by the light-receiving device when the light-emitting device is on and a signal outputted by the light-receiving device when the light-emitting device is off; and

processing alteration means for, on the basis of a detection result of the attachment state detecting means, altering detection processing for detecting the vital signal of the body.

2. The vital signal detecting apparatus of claim 1, wherein:

the attachment state detecting mean compares the signal outputted by the light-receiving device when the light-emitting device is on with the signal outputted by the light-receiving device when the light-emitting device is off and detects that the attachable device is detached when the two signals are of substantially the same level and detects that the attachable device is attached when there is a difference in level between the two signals.

3. The vital signal detecting apparatus of claim 1, wherein:

the attachment state detecting means detects the state of attachment/detachment of the attachable device to the body by comparing a d.c. component of the signal outputted by the light-receiving device when the light-emitting device is on with a d.c. component of the signal outputted by the light-receiving device when the light-emitting device is off.

4. A vital signal detecting apparatus of claim 1, wherein:

the processing alteration means stops the detection of the vital signal effected by the vital signal detecting means, when the attachment state detecting means detects that the attachable device is detached from the body.

5. A vital signal detecting apparatus of claim 4, wherein:

the processing alteration means restarts the detection of the vital signal or restarts a supply of operating power when a predetermined time has elapsed from a stopping of the detection of the vital signal effected by the vital signal detecting means or a stopping of a supply of operating power to the vital signal detecting means.

6. A vital signal detecting apparatus of claim 1, wherein:

the processing alteration means stops a supply of operating power to the vital signal detecting means when the attachment state detecting means detects that the attachable device is detached from the body.

7. A vital signal detecting apparatus of claim 1, further comprising:

a vital signal processing unit to which the vital signal is transmitted and which computes a parameter manifesting a state of the body on the basis of this vital signal,

wherein data relating to the state of attachment/detachment of the attachable device to the body is also transmitted to the vital signal processing unit and, while it is detected that the attachable device is not attached to the body, the processing alteration means stops the computing of the parameter based on the vital signal in the vital signal processing unit.

8. A vital signal detecting apparatus of claim 7, wherein:

the vital signal processing unit comprises reporting means for reporting to that effect, when data indicating a state of detachment of the attachable device to the body is transmitted to the vital signal processing unit.

9. A vital signal detecting apparatus of claim 1, wherein:

the attachment state detecting means includes a pushable part to be pushed by the body as the attachable device is attached to the body, and a detecting part for detecting whether or not the pushable part is being pushed.

10. A vital signal detecting apparatus of claim 1, wherein:

the attachment state detecting means has a temperature-sensitive device which responds to the body temperature when the attachable device is attached to the body.

11. A vital signal detecting apparatus of claim 1, wherein:

the attachment state detecting means has an electric circuit which incorporates the body as a part of the circuit when the attachable device is attached to the body; and

the attachment state detecting means detects attachment of the attachable device to the body by detecting a change in a resistor, a static capacitance or a potential occurring when the attachable device is attached to the body.

12. A vital signal detecting apparatus comprising:

a light-emitting device;

a light-receiving device; and

a light-transmitting plate disposed above the light-emitting device and the light-receiving device to pass light therethrough, and used with the surface of the light-transmitting plate in contrast with the skin surface of a human body,

wherein the light-receiving device is disposed in a position lowered by a predetermined distance with respect to the light-transmitting plate, and wherein

the light-emitting device is disposed closer than the light-receiving device to the light-transmitting plate.

13. A vital signal detecting apparatus comprising:

a light-emitting device;

a light-receiving device; and

a light-transmitting plate disposed above the light-emitting device and the light-receiving device to pass light therethrough, and used with the surface of the light-transmitting plate in contrast with the skin surface of a human body,

wherein the light-receiving device is disposed in a position lowered by a predetermined distance with respect to the light-transmitting plate, and

a window formed in a light-blocking layer that covers the surface of the light-transmitting plate and provided above the light-receiving device, the window for limiting the angle of incidence at which light can enter the light-receiving device.