Real-time Active Dosimeter (RAD)

Real-time Active Dosimeter (RAD)


Michael McRae
Biomedical Engineering

Nidaa Fawzi Bugis
Electrical & Computer Engineering

Brandon Shelby
Biomedical Engineering

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Project Description

Radiation exposure is especially hazardous to the wellness of people in certain professions (e.g., medical staff, spaceflight crewmembers, military personnel, nuclear waste management personnel, pilots, flight attendants, etc.). The widely-used method of passive dosimetry quantifies radiation exposure over a period of several months. Passive dosimeters are composed of thin sheets of film that, when exposed to radiation, develop the film. The amount of cumulative radiation absorbed by the body is directly related to the extent with which the film developed. Passive dosimetry, however, only quantifies radiation after the radiologic event has happened and the user is unaware of radiation emission. Active dosimeters, on the other hand, quantify radiation on a real-time basis and are capable of alarming the user when a high-energy radiologic event occurs. The user may then take appropriate countermeasures to reduce exposure. Therefore, a device that measures real-time and cumulative radiation doses are necessary; the Real-time Active Dosimeter (RAD) replaces the passive dosimeters currently used in professions with high risk for radiation exposure. The RAD implements a Geiger-Müller (GM) tube to sense X-ray and γ-ray emissions. The data is sampled by a microcontroller and the dose rate is stored in memory, integrating over time to acquire a cumulative dose. The user views the instantaneous dose rate and cumulative dose on an LCD screen and an alarm rings when a certain cumulative dose threshold is reached in accordance with National Council on Radiation Protection and Measurements (NCRP) standards.

Our team considered the following when designing the RAD:

  • An active dosimeter that quantifies both instantaneous dose and cumulative dose.
  • A dosimeter that can measure γ-ray and X-ray emissions.
  • A microdosimeter for personal-use (i.e., dimensions approximately 100 x 80 x 30 mm).
  • A battery-powered dosimeter with low operating voltage.
  • An LCD display of cumulative and instantaneous dose.
  • An audible alarm programmed to notify user when a certain dose threshold has been encountered.
  • A durable but radiation transparent plastic outer-casing.

The functions of the device are broken into four components: detection, data acquisition, algorithms, and display/alarm.  A conceptual image of the proposed design is shown in FIGURE 2.