FLUIDIC HEART SOUND SYNTHESIZING TECHNIQUES AND APPARATUS

• US 3,732,631 A
• Filed: 09/16/1971
• Issued: 05/15/1973
• Est. Priority Date: 09/16/1971
• Status: Expired due to Term

• Current Assignee: Mathew L. Petrovick
• Original Assignee: Mathew L. Petrovick
• Inventors: Petrovick, Mathew L.
• Primary Examiner(s): Skogquist, Harland S.
• Application Number:
  US05/181,004
• Time in Patent Office: 607 Days
• Field of Search: 35/17 137/81.5 235/2PF
• US Class Current: 434/266
• CPC Class Codes: F15C 1/008 Other applications, e.g. for air conditioning, medical applications, other than in respirators, derricks for underwater separation of materials by coanda effect, weapons
• CPC Class Codes: G09B 23/28 for medicine

Abstract

A novel method and apparatus for synthesizing the sound of a heart is disclosed. In the preferred structural embodiment, fluidic principles are employed and a fluidic system is constructed so as to include an oscillator, a controllable amplifier or wave shaping device, and a filling capacitance sound chamber or bladder, all interconnected one to the other by means of flexible and pliable tubing and impedance elements. Audible noise is generated in the system by periodically filling and discharging the sound chamber. Normal and clinical syndrome heart sounds can be synthesized from the audible noise by selectively varying switching of the Coanda air bubble within the fluidic amplifier, the flow rate, volume, and wave shape of the air or other fluid filling into and discharging from the chamber in a predetermined manner by means of adjusting system parameters. The sounds so produced can be monitored and utilized in medical training programs relating to cardiovascular sound diagnosis.

Claims

1. A method of synthesizing the sound of a human heart utilizing pure fluidic system components including an oscillator, a controllable amplifier, and a filling capacitance sound chamber interconnected one to the other, said method comprising the steps of:

generating audible noise by periodically filling and discharging the chamber;

synthesizing normal and critical syndrome heart sounds from the audible noise by selectively varying the Coanda pressure gradient/bubble, flow rate, volume, and wave shape of the fluid filling and discharging from the sound chamber in a predetermined manner; and

monitoring the heart sounds so produced at the sound chamber.

2. A method as defined in claim 1, including the step of utilizing a fluid selected from the group Consisting of milk, hydraulic fluid, oil, blood, water, saline, reagents, and combinations of biological fluids.

3. A method as defined in claim 1, further including the step of utilizing a fluid selected from the group consisting of gas, air, oxygen, and combinations thereof.

4. A method as defined in claim 1, further including the step of coating inner surfaces of selected elements within the fluidic system with an oil and water repellant compound so as to reduce static potential and enhance acoustic properties.

5. A method as defined in claim 4, wherein the coating comprises Zepel.

6. An apparatus for synthesizing the sound of a heart, said apparatus defining a fluidic system comprising:

a fluid oscillator means having a controllable rate;

a controllable wave shaping fluidic amplifier means coupled to said fluid oscillator means;

a fluidic capacitance sound chamber means;

variable impedance means including orifice means coupled between said amplifier means and said chamber means; and

monitoring means for monitoring audible sound generated in said chamber, the audible sound varying in accordance with the Coanda effect, fluid flow rate, volume, wave shape and orifice profile within said fluidic system.

7. An apparatus as defined in claim 6, wherein said orifice means of said variable impedance means comprises a plurality of orifices and restrictions of different shape and size selectively insertable into a fluid feed line coupled between said amplifier means and said chamber means.

8. An apparatus as defined in claim 6, further including a feedback fluid line coupled between said chamber means and said amplifier means so as to allow said chamber means to discharge, said feedback fluid line controlling operation of said amplifier means.

9. An apparatus as defined in claim 8, wherein said chamber means is elastic.

10. An apparatus as defined in claim 7, wherein fluidic lines couple said elements of the fluidic system together, said fluidic lines being constructed of resilient and flexible material to thereby simulate the hemodynamic effect of vaso-constriction and vasodilation, cause wave form changes in the fluid, and to create acoustic variability.

11. An apparatus as defined in claim 10, wherein said fluidic oscillator means comprises a fluidic flip-flop whose rate of oscillation is controlled by fluidic resistance-capacitance feedback loops.

12. An apparatus as defined in claim 11, wherein said controllable wave shaping fluidic amplifier means comprises a fluidic logic element.

13. An apparatus as defined in claim 12, wherein said fluidic logic element comprises a NOR gate.