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Circuits with amplifier

  1. Mar 21, 2008 #1

    I have project to design a device that measures the temperature of the brain first and then heats the blood to normal tempearture. it is used to treat hypothermia. In hypothermia, temperature of the blood drops down. i have designed a circuit for it. I have attached the pic. It is a neck patch which goes around the neck. I showd to my prof he said my circuit wont work. i need to change the circuit. i also need to show the equations for the circuit. Can someone help me with this???? Thank you

    Attached Files:

  2. jcsd
  3. Mar 21, 2008 #2


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    Gold Member

    Welcome to PF, Himansipatel.
    I'm afraid that I can be of no help to you. I'm wondering, though, if it might be worthwhile to open a post in 'Medical Sciences' directing people to this one. There's a strong possibility that someone there has experience with such things.
  4. Mar 26, 2008 #3


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    Staff: Mentor

    I may end up moving this to Medical Sciences as Danger suggests, but for now I'll keep it here.

    The circuit as you've drawn it does appear a bit odd. What is your intent with it? Are you trying to generate a voltage at the collector of the NPN transistor, based on the variable resistance (is that your temperature measuring element?)?

    Also, have you done much reading about treatment for hypothermia? Do you know what the contraindications are for active heating? What is the traditional method of active heating, and when is it indicated over passive heating?
  5. Mar 30, 2008 #4
    Where is the Vcc source?
    Which resistor is gonna heat the blood?
    It seems your transistor is the wrong type.
    Your circuit should have a kind of negative feedback (to keep things in control).
    Last edited: Mar 30, 2008
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