Stethoscope

Discussion in 'The Projects Forum' started by Mr.Smoke, Jun 2, 2006.

  1. Mr.Smoke

    Thread Starter Member

    May 26, 2006
    12
    0
    I have a question about the construction of stethoscope, basically stethoscope is an instrument by which one can hear his/her/others heart beats.
    from overview of it, I found that it consist of 2 ear piece( containing speakers ) like headphone, two wires which merge into 1, and get connected to a mic ( Peizo Crystal )
    As all the external structure of stethoscope is same as headphone.

    Now my question is that if I buy a headphone from market, and cut its connector and repalace it with peizo crystal, do it work? or I have to use something more? i.e. Amplifier if amplifier than what type of amplifier and how can one construct it.
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    Not sure if there is any advantage to a piezo xtal for the sound pickup. They have poor wide-band response.

    For the function, you need a mechanical isolator to screen out ambient noise and a pickup. A small funnel will serve the first purpose - you can cut a plastic one down to a reasonabel size easily. Modern stethoscopes have a mylar film across the bell, but it's not necessary, although saran wrap might do.

    For more accurate reproduction, though, a small microphone would be the thing to use. They are quite inexpensive, easy to mount in the stem of the funnel, and have outputs that go straight into sound card jacks or an audio amplifier. Ear buds might work, but at a lower sensitivity.
     
  3. Mr.Smoke

    Thread Starter Member

    May 26, 2006
    12
    0
    thanks
     
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