Method and apparatus for correlating respiration and heartbeat variability

• US 5,105,354 A
• Filed: 01/23/1989
• Issued: 04/14/1992
• Est. Priority Date: 01/23/1989
• Status: Expired due to Term

• Current Assignee: Toshihiro Nishimura
• Original Assignee: Nippon Kayaku Company Limited
• Inventors: Nishimura, Toshihiro
• Primary Examiner(s): Shaw, Dale M.
• Assistant Examiner(s): Huntley, David
• Application Number:
  US07/299,140
• Time in Patent Office: 1,177 Days
• Field of Search: 364/413.03, 364/413.06, 128/670, 128/671, 128/700, 128/702, 128/703, 128/706
• US Class Current: 600/484
• CPC Class Codes: A61B 2503/06 Children, e.g. for attention deficit diagnosis
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/344 Foetal cardiography
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: G16H 15/00 ICT specially adapted for medical reports, e.g. generation or transmission thereof
• CPC Class Codes: G16H 40/63 for local operation

Abstract

An evaluation method of respiration and heart beat and its apparatus which permits one to forecast sudden infant death syndrome by investigating correlation between respiration and heart beat in the normal state and sleep-apnea of a newborn.

Claims

1. A method of evaluating respiration and heart beat comprising:

detecting cardio-electric information from an organism;

calculating the variation of waveform interval for heart beat from the detected cardio-electric information;

detecting respiratory information from the above-mentioned organism;

calculating the envelope of the waveform of the detected respiratory information;

sampling said envelope information at a rate equal to the interval of the detected cardio-electric information;

calculating cross correlation between the variation of waveform interval of said cardio-electric information and the sampled envelope information of respiration;

identifying the highest value of cross-correlation; and

evaluating the degree of advancement or retardation between respiration and heart beat from said highest value of cross-correlation.

2. Apparatus for evaluating respiration and heart beat comprising:

means for detecting cardio-electric information from an organism;

means for detecting respiratory information from the above-mentioned organism;

means for calculating variation of waveform interval for heart beat from the detected cardio-electric information;

means for calculating the variation of waveform interval for heart beat from the detected cardio-electric information;

means for calculating the envelope of the waveform of the detected respiratory information;

means for sampling the envelope information at a rate equal to the interval of cardio-electric information;

means for calculating cross-correlation between the variation of waveform interval of said cardio-electric information and the sampled envelope information of respiration;

means for identifying the highest value of cross-correlation; and

means for evaluating the degree of advancement or retardation between respiration and heart beat from said highest value of cross-correlation.