Piezo element stethoscope

• US 8,320,576 B1
• Filed: 11/06/2009
• Issued: 11/27/2012
• Est. Priority Date: 11/06/2009
• Status: Active Grant

• Current Assignee: Rudolf Riester GmbH (Halma PLC)
• Original Assignee: Charles Richard Abbruscato
• Inventors: Abbruscato, Charles Richard
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): Fahnert, Friedrich W
• Application Number:
  US12/590,362
• Time in Patent Office: 1,117 Days
• Field of Search: 381/67, 381/71.5, 381/190, 600/498, 600/586, 600/528
• US Class Current: 381/67
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R

Abstract

A passive stethoscope chest piece has a chest piece housing containing a passive piezoelectric (piezo) element mounted within a metal housing. The piezo element converts body signals to an electrical representation. A pair of electrical connections attached to the metal plate and the piezoelectric layer of the piezo element pass the electrical representation outside the housing for processing by external circuitry. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Claims

1. A passive stethoscope chest piece, comprising:

a chest piece housing containing;

a passive piezoelectric (piezo) element with a metal plate;

a pair of electrical connections at the metal plate and a piezoelectric layer of the piezo element so that the piezo element serves to pick up body sounds and provides an electrical representation of the body sounds to the electrical connections and pass the electrical representation outside the housing for processing by external circuitry; and

where the housing includes a backstop comprising a post affixed to the housing and protruding toward a central area of the piezo element with their being a gap between the backstop and the piezo element so that the backstop contacts the piezo element if the piezo element is flexed toward the backstop by a distance equal to the gap.

2. The chest piece according to claim 1, where no active electronic components are disposed within the housing.

3. The chest piece according to claim 1, where the housing and metal plate are made from an inert or stable metal that can be sanitized in an autoclave or liquid sanitizing solution without degradation of operation.

4. The chest piece according to claim 1, where the housing is unsealed.

5. The chest piece according to claim 1, where the piezo element has approximately 570 mm squared of surface area.

6. The chest piece according to claim 1, where the piezo element has series capacitance of at least 10,000 pF.

7. The chest piece according to claim 1, where the electrical connectors connect to a cable and an external circuit, and wherein the capacitance of the piezo element is at least ten times the combined capacitance of the cable and external circuit.

8. The chest piece according to claim 1, where the back stop is situated so as to prevent the piezo element from flexing beyond a point that would damage the piezo element.

9. The chest piece according to claim 1, where the back stop is situated approximately 5-7 mm from a center of the piezo element.

10. A passive stethoscope chest piece, comprising:

a chest piece housing containing;

a passive piezoelectric (piezo) element with a metal plate and a piezoelectric layer;

a pair of electrical connections at the metal plate and ceramic disk of the piezo element so that the piezo element serves to pick up body sounds and provides an electrical representation of the body sounds to the electrical connections and pass the electrical representation outside the housing for processing by external circuitry, where no active electronic components are disposed within the housing; and

the housing having a back stop situated so as to prevent the piezo element from flexing beyond a point that would damage the piezo element, where a gap is provided between the backstop and the piezo element so that the backstop contacts the piezo element if the piezo element is flexed toward the backstop by a distance equal to the gap.

11. The chest piece according to claim 10, where the housing and metal plate are made from an inert or stable metal that can be sanitized in an autoclave or liquid sanitizing solution without degradation of operation.

12. The chest piece according to claim 10, where the housing is unsealed.

13. The chest piece according to claim 10, where the piezo element is approximately 570 mm square in surface area.

14. The chest piece according to claim 10, where the piezo element has series capacitance of at least 10,000 pF.

15. The chest piece according to claim 10, where the piezo element has a series capacitance of between 10,000 pF and 40,000 pF.

16. The chest piece according to claim 10, where the electrical connectors connect to a cable and an external circuit, and wherein the capacitance of the piezo element is at least ten times the combined capacitance of the cable and external circuit.

17. The chest piece according to claim 10, where the back stop is situated approximately 5-7 mm from a center of the piezo element.

18. The chest piece according to claim 10, where the backstop comprises a post affixed to the housing and protruding toward a central area of the piezo element.

19. A passive stethoscope chest piece, comprising:

an unsealed chest piece housing, where the housing and metal plate are made from an inert or stable metal that can be sanitized in an autoclave or liquid sanitizing solution without degradation of operation, the housing containing;

a passive piezoelectric (piezo) element with a ceramic disk and a metal plate having at least 10,000 pF in series capacitance;

a pair of electrical connections at the metal plate and ceramic disk of the piezo element so that the piezo element serves to pick up body sounds and provides an electrical representation of the body sounds to the electrical connections and pass the electrical representation outside the housing for processing by external circuitry, where no active electronic components are disposed within the housing;

where the electrical connectors connect to a cable and an external circuit, and where the capacitance of the piezo element is at least ten times the combined capacitance of the cable and external circuit; and

a post affixed to a top piece of the housing and forming a back stop situated approximately 5-7 mm from a central area of the piezo element so as to prevent the piezo element from flexing beyond a point that would damage the piezo element, with the top piece having a mass between 9 and 20 grams.

20. The chest piece according to claim 19, where the post is integral to a portion of the top piece of the housing.