A Measuring Medical Pocket Calculator

A measuring medical pocket calculator is presented. The hardware is built around a BASIC-Stamp microcontroller and includes a keyboard, a liquid crystal display, a dual analogue-to-digital converter, digital outputs and a serial port for data exchange with a personal computer. The software is based on a generic programmable calculator and can be adapted to suit specific applications. As an example, a dedicated audiologic calculator is presented. It features one-key conversions between different measures of acoustic levels, a hearing aid battery tester, automated calculation of percent hearing loss, and frequency specific, age-corrected comparisons (percentiles) to hearing thresholds of the general population.