Drip Rate Counter

Discussion in 'General Electronics Chat' started by OSOO, Mar 5, 2014.

  1. OSOO

    Thread Starter Member

    Feb 19, 2014
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    I am trying to design a circuit that counts the drops of the intravenous infusion pump using ir led , what is better to use in the receiver a phototransistor or photodiode ?? and why ?
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    What is the nature of the pump, does it operate on pulses?
    Or is it a peristaltic type pump?
    Max.
     
  3. crutschow

    Expert

    Mar 14, 2008
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    3,233
    A phototransistor is generally better for low speed signals since it has a much higher gain than a photodiode although its frequency response is lower.
     
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  4. #12

    Expert

    Nov 30, 2010
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    If it drips, you can count them.
     
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  5. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    If the drip tube is IR transparent, IR emitter VSMB2020X01, sm, gull wing would be a good match to transistor, also sm gullwing, VEMT2020X01, both by Vishay. I bought mine from Digi-key. Receiver body filters out daylight, operates around 940 nm.
     
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  6. wayneh

    Expert

    Sep 9, 2010
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    I'm pretty sure that the sensor clip they place on your finger to watch your pulse (and oximetry?) could easily sense IV drips. Just clip it on the IV tube and plug into your counter. The benefit of using a sensor that's already in the field appeals to me.
     
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  7. OSOO

    Thread Starter Member

    Feb 19, 2014
    34
    0
    Hi,



    I want to design a circuit that especially made to sense the drops of fluids in the medical infusion pump ,this is done by using of an ir led as a transmitter and phototransistor as a reciever , and whenever the drops pass between them , the light is interrupted ,then the voltage variations goes to microcontroller in order to calculate the drip rate of the infusion pump.


    This my circuit:


    [​IMG]

    What do you think? would it satisfy my purpose? ,do I need to add or remove any component ?

    I want to simulate it using isis proteus program but I couldn't find the phototransistor in the components library ,why !!? is there a way to simulate this circuit and how it's affected when drops falls down ?
     
  8. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    I merged the thread, as one thread per subject is enough.

    Bertus
     
  9. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
    783
    If the drips are in an expanded drip tube, aiming the beam could be tricky.

    I'm sort of thinking suggesting a reflective opto on the side of the plastic tube maybe.
     
  10. OSOO

    Thread Starter Member

    Feb 19, 2014
    34
    0

    I see,
    thanks
     
  11. OSOO

    Thread Starter Member

    Feb 19, 2014
    34
    0
    iv infusion pump

    a peristaltic pump based infusion pump operates via a stepper motor
     
  12. OSOO

    Thread Starter Member

    Feb 19, 2014
    34
    0

    Yes true , the same principle !
     
  13. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    If drip allignment is too critical, multiple IR receivers can be used. I stacked 5 surface mounts to give a 5 mm trap zone. Outputs fed into 8 in NOR IC. Tx- Rx spacing was 20 in.
     
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  14. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    As I remember, the IV drip sensors that we had contained 3 IR LEDs and 3 photo transistors. The LEDs were arranged in an arc of about 90° on one side of the chamber clamp. The photo-transistors were in a similar arc on the opposite side. There were thin, plastic, honeycomb, optical collimator sheets and IR filter film in front of the photo transistors. And collimators over the LEDs. The LEDs were electrically in series, and the photo-transistors had their collectors and emitters in parallel.

    Ken
     
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