Personal Dose Meter (Raysafe)

The Challenge

The Unfors RaySafe dosimeter is used in the healthcare sector to continuously measures the radiation dose that personnel are exposed to when carrying out various X-ray examinations. Updates are sent via radio link to a monitor system to control current doses and levels.

One major challenge in this project was battery life, as this was required to cope with at least five years of continuous operation. Another challenge was the requirement for high sensitivity measurement, down to individual X-ray photons. The dosimeter also had to be easy to wear and use.

The Solution

Thanks to our system design process we were able to create a product based on the requirements, both in terms of cost and performance. In order to fulfill the technical requirements, our only option was an ASIC solution. The extreme demands on low noise input and high sensitivity in combination with extremely low power consumption were impossible to achieve with standard components. A customized radio protocol was also developed that could connect to base stations and Internet, and which made possible the extreme demands on battery life possible.

Our ASIC solution made it possible to detect individual photons during continuous measurement while consuming only a few microamps of electricity. We implemented several radio and EMC measurements (known as pre-compliance) during the work, and were able to solve EMC-related problems early in the development process.

We collaborated closely with our Test Center, ShortLink Compliance, which was also responsible for the final EMC and radio testing, so that the customer was able to simply apply the CE mark to the product.

The Result

We have been deeply involved in developing a unique product; a product that did not previously exist on the market and which now protects healthcare personnel by continuously measuring the radiation doses they are exposed to, and giving them early warning of potentially harmful levels.

Relevant competencies: Wireless: Protocol design, ASIC development, Test Center.