ULTRASONIC DOPPLER BODY SURFACE MOVEMENT DETECTOR

• US 3,601,120 A
• Filed: 04/14/1969
• Issued: 08/24/1971
• Est. Priority Date: 04/14/1969
• Status: Expired due to Term

• Current Assignee: Kontron Inc (Roche Holding AG)
• Original Assignee: Harold Lee Massie
• Inventors: Massie, Harold Lee
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US04/815,724
• Time in Patent Office: 862 Days
• Field of Search: 128/2.5A,2.5R,2.5V,2.5S,2.6AR
• US Class Current: 600/453
• CPC Class Codes: A61B 8/04 Measuring blood pressure
• CPC Class Codes: G01S 7/52023 Details of receivers

Abstract

A device for utilization with an ultrasonic system for internal exploration of living organisms, enabling improved measurement of low blood pressure values by audible monitoring including modulating an audible tone frequency with the signals to be detected to generate a distinct audible signal rhythm which can directly be detected by human ear and distinguished from noise.

Claims

1. In a system for audibly indicating the movement of surfaces in living organisms by emitting ultrasonic energy and receiving the ultrasonic doppler energy reflected from a moving surface and detecting from the reflected ultrasonic energy electrical doppler signals containing amplitude information and frequency information representative of said surface movement, the combination comprising filter means for receiving said doppler signals to avoid low frequency base line drift, frequency generating means for providing an audio frequency carrier having a higher frequency than said detected doppler signals suppressed carrier modulating means connected from said filter means and provided with said audio frequency carrier to modulate said audio frequency carrier with said doppler signals for generating a distinct rhythmical audio frequency burst pattern which has effectively the same amplitude and is directly related in frequency to said detected doppler signals.

2. The combination according to claim 1 wherein said suppressed carrier modulating means includes a balanced modulator.

3. The combination according to claim 1 wherein said suppressed carrier modulating mans includes:

a modulator unit, full wave rectification means connected to said modulation unit.

4. The combination according to claim 3 wherein said means for generating said pattern further comprises gain control means connected with said filter means to set the noise level of the incoming signals, automatic gain control means connected from said filter means and to said rectification means to maintain constant signal level, amplifying means connected from said modulating means for providing an output signal, and feedback mans connecting the output of said amplifying means to said automatic gain control means.