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Portable Glucose Meter

Aditya Ayachit1
Prodigy 50 points

I am in the process of designing a portable glucose meter for my customer. By the basics that I have read I find that amperometry is one of the solutions. Using this solution I would like to implement a Single IC solution using an MSP430.

According to the preliminary data with me the max full scale current to be measured in 3000 nA. Is it possible to measure this small current using the FG series? Please let me know.

I have worked on Low Power instruments using MSP430F44X series before so memory (Flash), display, digital IO and Low power modes are something I am comfortable with.  

Thanks in advance.

 Aditya Ayachit 

  • 0
    Guru 227245 points

    well 3000nA over a 1MOhm resistor gives 3V :)

    However, you have a significant input current into the MSP. Significant if the signal source has an output impedance on the Mohm range.

    I suggest using an OpAmp as pre-amplifier and impedance changer. Create an output voltage by loading the sensor output with 10k or 100k and source it into an OpAmp with J-Fet inputs (several MOhm input impedance) and amplify it by 10 or 100.

    For the SAR converters (ADC10/ADC12) you could try to directly soure the sensor output into the ADC input buffer. Given a long enough sampling time, this should give an acceptable result (capacitor charge by current). With the Delta-Sigma converters (SD16/SD24) with continuous input comparison, this won't work.

  • 0
    Prodigy 30 points

    Hi,

    I think you have researched much in making glucose meter. Can you help me regarding, what type of sensor should be used in making the device?

    Can you provide data-sheet?

    Thank You.

  • 0 in reply to Vishvesh Shah
    Prodigy 10 points

    Hello,


    I am in a stage of development glucometer, please, Can you help me regarding, what type of   Blood Glucometer test strips  should be used ?

    Can you provide data-sheet?

    Thank you,

    Cordially,


  • 0
    Genius 4090 points

    The MSP430F44x supports ADC with 12 bit resolution.

    Now using an low voltage operational amplifier with appropriate gain settings you can limit the measurement current and the resolution of measurable  current.

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