Electronic stereophonic amplifier

• US 6,219,424 B1
• Filed: 04/16/1999
• Issued: 04/17/2001
• Est. Priority Date: 05/04/1998
• Status: Expired due to Fees

• Current Assignee: Hunter Area Health Service
• Original Assignee: Hunter Area Health Service
• Inventors: Murphy, Edward John
• Primary Examiner(s): Mei, Xu
• Application Number:
  US09/293,359
• Time in Patent Office: 732 Days
• Field of Search: 381/67, 381/1, 381/28, 381/120, 600/528, 600/586, 181/131, 181/137, D24/134, 330/301, 333/4
• US Class Current: 381/67
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R

Abstract

A device for use in a stethoscope, the device including two diaphragm-type sound accumulator chambers, one microphone located in each accumulator chamber and one amplification stage connected to each microphone for electronically amplifying audio signals received by the microphones, and an output connector for outputting the amplified audio signals.

Claims

1. A device for use in a stethoscope, the device including:

two diaphragm-type sound accumulator chambers;

one microphone located in each accumulator chamber;

one amplification stage connected to each microphone of electronically amplifying audio signals received by the microphones; and

an output connector for outputting the amplified audio signals, wherein the amplification stages are connected to one common earth potential and the output connector is arranged in a manner such that negative inputs of sound transducers which are in use connected to the connector are connected to the common earth potential via an impedance.

2. A device in accordance with claim 1 wherein the impedance is chosen to be substantially the same as the impedances of the sound transducers which are in use connected to the output connector.

3. A device in accordance with claim 2 wherein the impedance is a resistor.

4. A device in accordance with claim 2 wherein each amplification stage includes a variable gain control.

5. A device in accordance with claim 4 wherein the variable gain controls of the amplification stages can be adjusted simultaneously and in a manner such that the variation is the same for each amplification stage.

6. A device in accordance with claim 4 wherein the variable gain control of each amplification stage is independently adjustable.

7. A device in accordance with claim 2, wherein the accumulator chambers are located on a housing and separated by a distance, and wherein diaphragms of the accumulators are facing outwardly from the housing.

8. A device in accordance with claim 7, wherein the distance is fixed.

9. A device in accordance with claim 7, wherein the distance is variable.

10. A device in accordance with claim 2, further including a power-on indicator which includes a high brightness blue light emitting diode (L.E.D.).

11. A stethoscope including:

two diaphragm-type sound accumulator chambers;

one microphone located in each accumulator chamber;

one amplification stage connected to each microphone for electronically amplifying audio signals received by the microphones;

and a transducer connected to each amplification stage for transducing the amplified audio signals as a sound signal, wherein the amplification stages are connected to one common earth potential and the negative inputs of the transducers are connected to the common earth potential via an impedance.

12. A stethoscope in accordance with claim 11, wherein the impedance is chosen to be substantially the same as the impedances of the transducers.