Electrical Capacitance Tomography
This prototype was designed and built as a final project for the class Sensor Technologies For Interactive Environments [MAS836], Spring 2017.
This project is open source, fork it at Github.
The circuit uses, due to a class requirement, only analog capacitive signals and analog filters. An Arduino Uno was added merely to convert the analog signals from the OpAmps to digital readings, Sending to the graphical user interface.
The concept behind this circuit is very simple, the signal will be bounced between all sensors, in pairs. Then comparing all the radings a estimative of the fingers bone density will be generated.
The UI was created with focus in the Data Visualization for a quick prototype validation. In this case the realtionship between all sensors was necessary to a contextual sensor analysis. Using the Processing platform (Java), this software reads the output in a specific serial port and plots it in both line chart (for individual sensors signal analysis) and in a custom radial shape (for sensors group analysis).
Using rapid prototyping techniques, e.g. 3D printing, and low cost materials like hot glue and copper vinyl this prototype was built in less than 12h. From the first sketch to the final device connected with UI.