The proposed sensor for the PVAD should detect when the pump is in end-diastolic in order to achieve this goal, as specified by Dr. Weiss. However, the CardiacKids hoped also to determine end-systole position as well. Several design concepts were evaluated based on the design criteria for the PVAD. A duel approach, using an optical sensor and a contact sensor, was taken to fulfill the task. The contact sensor detected when the pump was in end-diastole and the optical sensor detected end-systole.

The main objectives of this project included:

(1).	Design and development of the sensor and output system that could designate when the blood sac of the PVAD was completely full.
(2).	Allowance of the system to be used by non-technical medical personnel.

In order to reach the first objective, we set a goal to develop sensors that would determine the position of the diaphragm. This involved the potential for the collaboration of two sensors and an output system. The sensors needed to be able to detect a rate of 0-150 beats per minute in a pulsatile flow environment.

Another requirement of the design was that it must also be user friendly. The user of the device simply needs to know when the blood sac is performing at an optimum level without having to do calculations or analyze data. Within a range of 0 to 5 volts, the change in voltage output should be proportional to the diaphragm position. This will allow the user to see when the senor has reached a calibrated voltage that represents the peak position of the diaphragm. With this information, the user can confirm that the device is working to its full potential or determine if any complications arise.