The Tetra Button Pusher

Project Description:

People who are bedridden are often able to adjust the position of their medical bed using a remote control. However, some people are unable to use this remote because of additional mobility issues. Current solutions to this problem are too expensive for most people in these circumstances to afford. This has caused the Tetra Society to propose that an inexpensive voice-activated method of adjusting this type of bed be developed. Because of price constraints, the budget for this project is $500.00. The solution should also provide the ability for helpers and/or caretakers, who are aiding the bedridden person in question, to use the remote in its intended way.

The solution consisted of designing and building a mechanism that could react to voice commands issued to a Google Home to raise or lower the headrest, footrest, and height of a hospital bed. This was accomplished using an ESP32 microcontroller to process commands, and analog feedback servo motors to physically interact with the buttons on the bed remote. The device also has a setup routine where the primary user can calibrate the system, set up the positions of the buttons, and fine tune the control parameters such as what increments in percent they would like to be raised/lowered by.
Fortunately, we were actually able to develop a working prototype for our system to see how it would perform. We ended up testing the system on a calculator instead of a bed remote due to visitation and time constraint issues, but the functionality remains the same. The arm was able to be calibrated and positioned over top of buttons to save the servo angles for when they needed to be called. Then, when a Google home was issued a command like “Hey Google, Raise Head” It would turn on the calculator.

This project was an enjoyable and worthwhile learning experience that has developed a thorough understanding of engineering principles and practices. The project involved designing models on paper, creating them in 3D space within CAD software, and then bringing them to life with 3D printing; or creating custom circuit schematics and PCB layouts to be ordered; along with component lists, and bills of material; or writing user interfaceable programs that operate the system with code derived from control system; and kinematic theory. All of this and more have culminated to be a well encompassed project that has taught us what it takes to develop and construct a consumer worthy product. Though we did not fully flesh out all aspects of the project, with future time and development this project could be turned into a consumer ready device.

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