Biophysical sensor

• US 6,988,993 B2
• Filed: 06/20/2001
• Issued: 01/24/2006
• Est. Priority Date: 06/22/2000
• Status: Expired due to Term

• Current Assignee: Australian Centre For Advanced Medical Technology Pty Ltd.
• Original Assignee: Australian Centre For Advanced Medical Technology Pty Ltd.
• Inventors: Sullivan, Colin Edward, Bianchi, Ricardo
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US10/297,366
• Publication Number:
  US 20040039294A1
• Time in Patent Office: 1,679 Days
• Field of Search: 600/500, 600/528, 600/534, 737/08, 324/457
• US Class Current: 600/528
• CPC Class Codes: A61B 2562/0204 Acoustic sensors
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 7/003 Detecting lung or respiration noise
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: B06B 1/0688 with foil-type piezoelectric elements, e.g. PVDF
• CPC Class Codes: G01H 1/00 Measuring characteristics of vibrations in solids by using direct conduction to the detector G01H9/00, G01H11/00 take precedence

Abstract

A biophysical sensor including a sound vibration sensing element (12) to produce a sensed output, and two or more separate signal processing paths to process the sensed outputs to produce output signals. The output signals may reflect specific frequency bands within the raw biological signal. In a further aspect the invention concerns an electronic stethoscope in which the sound vibration sensing element (12) is a PVDF membrane, the signal processing involves an operational amplifier (OP amp) (10) connected to the PVDF membrane, and a unity gain buffer amplifier is connected to the output of the OP amp to allow the connection of headphones directly to the sensor output.

Claims

1. A biophysical sensor including a sound vibration sensing element using a PVDF membrane to produce a sensed output, and at least two separate signal processing paths to process the sensed output to produce at least two output signals;

where one signal processing path includes an operational amplifier (OP Amp) connected to the PVDF membrane and for amplifying an audible frequency range of the sensed output to an audible amplitude range, and a unity gain buffer amplifier is connected to the output of the OP Amp to allow connection of headphones directly to the sensor output.

2. A biophysical sensor according to claim 1, further including recording and display apparatus to record and display the output signals.

3. A biophysical sensor according to claim 1 or 2, where the output signals are two, or more, of heart sounds, heart movement, breathing movement and breathing sounds.

4. A biophysical sensor according to claim 1, where a silver coating on the PVDF membrane is used to take off electrical signals.

5. A biophysical sensor according to claim 1, where the signal processing includes floating amplifiers mounted on a printed circuit board inside the sensor housing.

6. A biophysical sensor according to claim 1, where the OPAmp uses the intrinsic capacitance of the PVDF together with a resistance to create a high pass filter.

7. A biophysical sensor according to claim 6, where alternatively, or in addition, an OPAmp is AC coupled directly to the PVDF membrane.

8. An electronic stethoscope, comprising a biophysical sensor including a sound vibration sensing element which uses a PVDF membrane to produce a sensed output, signal processing involving an operational amplifier (OPAmp) connected to the PVDF membrane and for amplifying an audible frequency range of the sensed output to an audible amplitude range, and a unity gain buffer amplifier connected to the output of the OPAmp to allow connection of headphones directly to the sensor output.