march22meeting

March 22, 2007

 

I.  Reports

    A.  Lloyd +Jeff - The transmitter design has been switched with a more pre-optimized solution.  

          The current design of the device is as follows:

                  -Variable inductor strap varies the generated frequecny of the variable oscillator.
                  - A high frequency OP amp is used to digitize the signal from the variable oscillator as well as from

                    crystal oscillator( this will be used later as a clock signal).

                  - The digitized variable oscillator signal will be input to a Programmable Logic Device(PLD).

                     The PLD will utilize the digitized crystal oscillator signal as a clock signal to sample the                                  variable oscillator signal every #(x)ms.

                  - The sampled frequency will be converted to a 32 bit binary number and sent to the Xbee                              transmitter in two 16 bit packets, (as is  required by the Xbee)

                  - The Xbee will then transmit the data packets and the corresponding receiver unit will pick up the data
                  -The data will then be processed with a digital filter to eliminate inconsistencies generated by                     noise.  An average will be deduced and sent into the control unit. 

 

II.  New Business.

    A.  New shirt design idea - utilizes an elongated section of flexible material  to connect the sides of a         "sandwitch board" section of inflexible material.   Wires can be run along the seam where the two             materials meet.

    B.  Injection Molding - Keep looking at our options.  

 

III.  Considerations for future.

    A.  If transmitting circuitry is to be attached to the bottom of the foot, what maximum weight would               we be comfortable with for the the circuitry unit?

   B.  It should not take much extra effort to turn the monitor into an audio monitor as well.

   C.  Allthough it will increase the complexity of the controller unit by a factor of 10, it should not cost              much more in space or money to allow the monitor to activate an alarm upon detecting a                          significantly decreased rate of breathing. 

    D.  There should be a built in function to deactivate the alarm if  breathing starts again.

    E.  To conserve power, the transmitter should only transmit when a problem is detected.

  
 

IV.  Action Items

    A. Lloyd- Design digital interfacing circuitry to be used with Xbee. 

    B.  Jennifer, Colby, Bart, Chris, - Meeting with Laila 1:30 sunday to work on the shirt and inductor.

    C.  Jeff- Develop PCB layout