Development and clinical testing of a concept for a medical device is a good start. DEMCON is also deployed for the other half of the work – realising a product that is ready for the market and organising serial production. Hemics in Eindhoven did this for a non-invasive imaging system that can visualise inflammation activity in rheumatoid arthritis. The use of the system can help to improve quality of life for patients and to reduce treatment costs. Hemics approached DEMCON for the step to practical application.
Benefits of the HandScan
The HandScan measures blood flow in joints in the hands and wrists through diffuse optical transmission in combination with blood flow modulation. Optical technology makes the system safe for the patient and cheap and fast to use: a session lasts only 2.5 minutes. A cuff temporarily cuts off the blood flow in the patient’s lower arm, leading to blood accumulation. The hand is lit from below, and with the transmitted light a camera records a series of grey scale images of the back of the hand, which are translated into special measurement values. By measuring two wavelengths, red and infra-red, subtle differences in blood flow in the joints can be accurately determined. These differences provide information on the degree of inflammation.
Hemics markets the HandScan as a compact, user-friendly and affordable appliance. It is itself responsible for the data algorithm that translates the measurement data from the scanner into clinical information for the rheumatologist. DEMCON provides for the systems engineering, electronics, mechanics, optics and the embedded software. In addition to the lighting module, an intuitive user interface and the industrial design require special attention, with a view to acceptance of the appliance in day-to-day rheumatology practice.
The first option for the lighting was a matrix of high-power LEDs, but preference was given to the alternative scanning laser concept of DEMCON, based on rotating mirrors, due to its greater suitability for production and greater flexibility in the design of the functionality. For an acceptable signal/noise ratio, the light intensity below the hand must be stable. Reflections and ‘leakage’ of light between the fingers must be ruled out. For this reason, the moving laser beam is continually switched on and off, on the basis of a virtual mask generated from pre-recorded images of the hand and wrist. The main technical design challenge lay in the interaction of the camera and the control/synchronisation of the two lasers.
DEMCON realised a prototype, together with partners for the optical and the industrial design. A line for serial production was then set up. The first HandScans from the pre-production run were used for clinical trials. The market was already enthusiastic and now, partly thanks to the deployment of DEMCON, the system is ready to prove itself in day-to-day practice.