Auscultatory training system

• US 7,209,796 B2
• Filed: 04/29/2002
• Issued: 04/24/2007
• Est. Priority Date: 04/30/2001
• Status: Expired due to Term

• Current Assignee: United States Department Of Health And Human Services (Government of the United States of America)
• Original Assignee: The United States of America As Represented By The Secretary of Agriculture
• Inventors: Frazer, David G., McKinney, Walter G., Goldsmith, William T., Friend, Kimberly A., Reynolds, Jeff S.
• Primary Examiner(s): Tran; Sinh
• Assistant Examiner(s): Sellers; Daniel R.
• Application Number:
  US10/135,964
• Publication Number:
  US 20020183874A1
• Time in Patent Office: 1,821 Days
• Field of Search: 700/94, 434/266, 600/528, 600/586, 381/67, 381/71.1, 381/71.6, 381/71.7, 381/94.1, 381/94.2
• US Class Current: 700/94
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: G09B 23/28 for medicine

Abstract

According to a disclosed embodiment, an auscultatory training apparatus includes a database of pre-recorded physiological sounds stored on a computer for playing on a playback system. A user-friendly, graphical user interface software program is stored on the computer for use with a conventional computer mouse. The program allows a user to select one of the pre-recorded sounds for playback. In addition, the program is operable to generate an inverse model of the playback system in the form of a digital filter. If employed by the user, the inverse model processes the selected sound to cancel the distortions of the playback system so that the sound is accurately reproduced in the playback system. The program also permits the extraction of a specific sound component from a pre-recorded sound so that only the extracted sound component is audible during playback.

Claims

1. An auscultatory training apparatus comprising:

a playback system;

a computer having memory means for digitally storing a database of pre-recorded, physiological sounds for playing on the playback system, means for selecting one of the pre-recorded sounds for playback, means for generating an input digital signal of the sound selected for playback, a digital to analog converter for converting the digital signal into an input analog signal, an analog to digital converter to receive an analog output signal from the playback system and convert the output signal to a digital signal, and reconstruction means for reconstructing the input digital signal so as to cancel the distortions of the playback system for accurate audible reconstruction of the sound in the playback system, wherein the reconstruction means comprises an inverse model of the playback system in the form of a digital infinite impulse response filter; and

the playback system including an amplifier for receiving and amplifying the input analog signal from the digital to analog converter, an output speaker connected to the amplifier for converting the analog signal received from the amplifier into an audible reconstruction of the selected sound, an elongate tubular member positioned proximate the speaker so that sound from the speaker travels through the tubular member, a listening mechanism operatively coupled to the tubular member to enable a user to listen to the reconstructed sound, and a microphone mounted on the tubular member and connected to the analog to digital converter, the microphone operable to convert the audible sound into an output analog signal and transmit the output signal to the analog to digital converter.

2. The apparatus of claim 1 further comprising display means for displaying a time signal of the selected sound and a time signal of the reconstructed sound to provide a visual indication of the fidelity of the reconstructed sound.

3. The apparatus of claim 1 further comprising means for selecting a specific sound component of the selected pre-recorded sound for playing in the playback system.

4. The apparatus of claim 3 further comprising display means for displaying a spectrogram of the sound selected for playback, means for selecting a region of the spectrogram corresponding to a specific component of the sound, and means for filtering the selected component from the sound so that only the selected component of the sound is audible during playback.

5. The apparatus of claim 1 wherein the listening mechanism comprises a stethoscope comprising a pair of earpieces and a tube acoustically coupled to the earpieces and having an input end disposed inside the tubular member at a location adjacent the microphone so that the microphone and the input end of the stethoscope obtain approximately the same sound pressure wave.

6. The apparatus of claim 5, wherein the speaker is located at one end of the tubular member spaced from the microphone and the input end of the stethoscope.

7. An auscultatory training apparatus comprising:

a playback system;

memory means for digitally storing a database of pre-recorded, physiological sounds for playing on the playback system;

means for selecting one of the pre-recorded sounds for playback;

display means for displaying a spectrogram of the sound selected for playback;

means for selecting a region of the spectrogram corresponding to a specific component of the sound;

means for filtering the selected component from the sound so that only the selected component of the sound is audible during playback; and

reconstruction means for reconstructing the selected sound component so as to cancel the distortions of the playback system for accurate audible reconstruction of the sound component in the playback system;

wherein the playback system comprises an output speaker for producing an audible form of the selected sound component, an elongate tubular member coupled to the speaker so that sound from the speaker travels through the tubular member, and a listening mechanism operatively coupled to the tubular member to enable a user to listen to the reconstructed sound component.

8. The apparatus of claim 7 wherein the reconstruction means comprises an inverse model of the playback system in the form of a digital infinite impulse response filter.

9. The apparatus of claim 7, wherein the speaker is located at one end of the tubular member and the listening mechanism comprises a stethoscope having an end portion disposed in the tubular member at a location spaced from the speaker.