Method for recording foetal movements during pregnancy and apparatus for carrying out the said method

• US 4,809,702 A
• Filed: 11/10/1987
• Issued: 03/07/1989
• Est. Priority Date: 11/20/1981
• Status: Expired due to Fees

• Current Assignee: Universite De Franche-Comte
• Original Assignee: Universite De Franche-Comte
• Inventors: Fabbri, deceased, Marcel, Colette, Claude, Brandon, Jean-Francois, Fabbri-Ollinger, legal representative, Marie O. P., Weichlein, Bernard
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US07/119,062
• Time in Patent Office: 483 Days
• Field of Search: 128/660, 128/661, 128/24 A
• US Class Current: 600/453
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: A61B 8/0866 involving foetal diagnosis; pre-natal or peri-natal diagnosis of the baby

Abstract

A method and an apparatus for recording foetal movements comprising a pick-up which forms part of an ultrasonic transducer connected, on the one hand, to an electric wave emitter device and, on the other hand, to a device for receiving and analyzing the electric waves obtained from the ultrasonic waves which have been reflected by the foetus and received by the transducer.

Claims

1. Apparatus for recording foetal movements during pregnancy, comprising ultrasonic transducer means connected, on the one hand, to an electric wave emitter device for emitting ultrasonic waves at an emission frequency and, on the other hand, to a device for reception and analysis of the electric waves obtained from said ultrasonic waves which have been reflected by a foetus and received by the transducer means connected to said reception and analysis device and which have a frequency different from the frequency of the emitted ultrasonic waves due to the Doppler frequency shift produced by a movement of the foetus,

wherein said reception/analysis device comprises

amplitude detector means for determining Doppler frequency shift signals having an amplitude value higher than a predetermined threshold level as significant foetal movement signals,

signal selector means responsive to any significant foetal movement signals spaced from a preceding received significant signal by a time interval greater than a predetermined value and providing an output thereof, and

a counter adapted to be incremented by the output of said signal selector means to thereby record movement of said foetus.

2. Apparatus according to claim 1, wherein said amplitude detector means comprises

a DC offset circuit adapted to DC shift the received foetal movement signals by a DC value corresponding to said threshold level, and

zero crossing detector means coupled to the output of said offset circuit for ensuring zero crossing only of signals having an amplitude greater than said threshold level.

3. Apparatus according to claim 1, wherein said signal selector means responsive to said time interval spaced signals comprises

a monostable multivibrator device adapted to be set by the beginning of a time interval spaced signal and provided with means for establishing a predetermined time constant preventing resetting of said multivibrator during said time interval after the end of said signal by which said multivibrator has been set.

4. Apparatus according to claim 3, wherein the transducer means, the reception/analysis device, and the counter are mounted in a casing which is adapted to be secured to the surface of the mother'"'"'s abdominal skin.

5. Apparatus according to claim 3, wherein the transducer means, the reception and analysis device, and the counter are mounted in a casing which is provided with a strap for securing and retaining said casing on the mother'"'"'s abdominal skin.