Medical Pocket Calculator And Its Use In Measuring Acoustic Signals

By | February 10, 2015

A measuring medical pocket calculator is used for measuring acoustic levels, a hearing aid battery tester, percent hearing loss and frequency specific in hearing , hearing thresholds of the general population. With the usage of cheap and micro controllers it is possible to build a pocket calculator for needs in medical filed. .Since their invention pocket calculators have become routine accessories of everyday life. As it is cheaply available it can be easily developed for a particular application. Instead of using a computer screen for some medical areas the general calculators can be turned in to medical calculators. Medical personnel feel complex using with too many keys and functions, which they do not need and understand. Hence an application-specific calculator can give the desired information faster to the end user thus minimizing errors. The application specific measuring calculator was found to be helpful in everyday routine work.

Design of a basic medical pocket calculator
The hardware is built around a BASIC-Stamp micro-controller 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 programmable calculator and can be used to suit particular needs.

Steps included in designing:

1. A basic calculator will be programmed in two versions for adding 3 and 5

  • Reversed polish notation (RPN).
    • In this version for addition the operators are used in this way [3] [ENTER] [5 ] [+ ]
  • Algebraic data entry.
    • In this version of programming the addition follows to be [3 ] [+ ] [5 ] [= ]

2.Higher mathematical functions like square root and logarithm are included.

3.conditional and unconditional branching of the steps is done automatically.

All of the features mentioned take 66 % of the available memory. Thus , leaving sufficient space for specific operations.

A pocket calculator for audiology test

In this pocket calculator for audiology test the less important features like absolute values , integers are removed and other functions including the basic programmable were kept.
The following specialized calculations for audiology test are added :

• Calculation of percentage of hearing loss from hearing thresholds
• Percentage of population with poorer hearing thresholds as a function of frequency and age
• Conversion of linear amplitude to decibel (dB) and vice versa.
• Conversion of dB Sound Pressure Level to dB Hearing Level (normal) and vice versa.
• Measuring the voltage of batteries for hearing aids and speech processors for cochlear implant


  • It can be used in measuring the body mass index in general population.
  • It can be used to know the percentage hearing loss of an ear.
  • The hearing threshold level can be known.

Advantages over other non specific pocket calculators :

  • No start-up time is required to select the necessary software application.
  • It is highly portable.
  • No need to use large computer screen between the physician and the patient for displaying the results.

Hence in present days the use of pocket calculators specifically for medical use with a particular application is considered useful present days. .With its capability to measure electrical parameters directly and to download data via the personal computer, special function outside the scope of commercially available calculators can be realized.