Heartbeat synchronous information acquiring apparatus

• US 6,748,262 B2
• Filed: 08/09/2001
• Issued: 06/08/2004
• Est. Priority Date: 08/09/2001
• Status: Expired due to Fees

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Colin Medical Technology Corporation (Omron Corporation)
• Inventors: Harada, Chikao, Kawaguchi, Keizoh, Narimatsu, Kiyoyuki, Yokozeki, Akihiro
• Primary Examiner(s): Schaetzle, Kennedy
• Assistant Examiner(s): DROESCH, KRISTEN L
• Application Number:
  US09/924,512
• Publication Number:
  US 20030032887A1
• Time in Patent Office: 1,034 Days
• Field of Search: 600/300-301, 600/481, 600/483, 600/485, 600/500, 600/502, 600/504, 600/506, 600/508-510, 600/513, 600/547
• US Class Current: 600/513
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295

Abstract

The gate means 73 extracts the partial impedance pulse wave SM_IMP(P) from the thorax impedance pulse wave SM_IMP detected by the thorax impedance pulse wave detector 64. This is done over an intake period defined as a period starting from a first time T₁ after the time when the R wave of the induced electro-cardiac wave is detected to the time when a rising edge of the photoelectric pulse wave SM₂ is detected. Then, the heartbeat synchronous information determining means 74 selects a rising edge of the partial impedance pulse wave SM_IMP(P) that periodically appears as heartbeat synchronous information I_H. Thus, it is possible to accurately determine the heartbeat synchronous information I_H. Additionally, since the photoelectric pulse wave SM₂ that is detected by the photoelectric pulse wave sensor 40 is largely free of noise it is possible to accurately determine the end of the period for reading the thorax impedance pulse wave SM_IMP.

Claims

1. A heartbeat synchronous information acquiring apparatus provided with an impedance pulse wave detector for detecting an impedance pulse wave of a living body containing heartbeat synchronous components between a pair of electrodes fitted to predetermined positions of the living body with a heart interposed therebetween in order to acquire the heartbeat synchronous information generated synchronously with heartbeats of the living body based on the impedance pulse wave, said apparatus comprising:

an induced electro-cardiac wave detection device for continuously detecting an induced electro-cardiac wave of said living body;

gate means for extracting a partial impedance pulse wave from the impedance pulse wave by taking in the impedance pulse wave for an intake period based on the time of detection of a predetermined part of the induced electro-cardiac wave by the induced electro-cardiac wave detection device; and

heartbeat synchronous information determining means for determining a periodically appearing predetermined part of the partial impedance pulse wave extracted by the gate means as heartbeat synchronous information.

2. The heartbeat synchronous information acquiring apparatus according to claim 1, wherein

said intake period of said gate means is from the end of a predetermined first time period starting from the time of detection of the predetermined part of the induced electro-cardiac wave by the induced electro-cardiac wave detection device to the end of a predetermined second time period starting from the time of detection of the predetermined part, said second time period being longer than said first time period.

3. A heartbeat synchronous information acquiring apparatus according to claim 1, further comprising a photoelectric pulse wave sensor for detecting a photoelectric pulse wave at a part irradiated with light, said sensor being provided with a light source for irradiating a skin of said living body with light, and a photo detector for detecting transmitted or reflected light originating from said light source,

the intake period of said gate means being from the end of a first time period starting from the time of detection of the predetermined part of the induced electro-cardiac wave by the induced electro-cardiac wave detection device to the time of detection of the predetermined part of the photoelectric pulse wave by said photoelectric pulse wave sensor.