Final Design

Below is a C.A.D drawing showing the final design set up:

Below is an explosion schematic showing  the neoprene layers and push button alignment of the cushion.

Instruction Manual

For more information on how to operate the Auto-PRT click here.

Final Design Evaluation

Conclusions and Recommendations

The 10 pushbutton multi-sensor Auto PRT meets all sponsor design specifications and has proven to be an effective tool for the prevention of pressure sores. It is a valuable advancement from the former single-sensor design because it accommodates side-to-side partial pressure-relief exercises in addition to full-pressure relief exercises for patients that are not physically capable of completing the full-pressure relief exercise. Most notably, the Auto PRT has the capability to track how long a patient has held an acceptable pressure-relief exercise and will prompt subsequent alarms if a patient sits down too quickly until a summation of 15 seconds is achieved. This ensures that the patient completes an acceptable exercise, even if he/she does not achieve it in one attempt. The device has proven to be robust under fatigue testing. Its timing system has demonstrated a high degree of accuracy and precision in all test trials regardless of patient-size or type of pressure-relief exercise performed. In addition, the total cost of making this device was $107.39, and thus is feasible to produce on a large scale.


Additional considerations that have been made for patient-convenience include an easy-to-clean vinyl casing that provides protection from liquids/incontinence and the incorporation of a toggle switch that allows the user to choose between an auditory and visual alarm. Moreover, the entire device is easily detachable for convenience during travel and transferable between multiple chairs.


Future amendments that would be valuable to this design would be the incorporation of a vibrating alarm to use in environments that do not elicit the use of auditory or visual alarms such as movie theaters, concerts, etc. In addition, sealing the vinyl cover material as well as the small and large electrical enclosures would further enhance the water and incontinence resistance. Another aspect of the system that deserves attention is the inability to troubleshoot maintenance issues that occur with the push buttons. Currently the buttons are tightly pressed in between cemented layers of rubber and connected to the main circuit through long wires that cannot be accessed unless the system is completely taken apart. To amend this issue, wireless technology can be incorporated to eliminate all wiring from the cushion to the circuitry.

The Final Budget

Gant Chart