Engineering Insight

ENGINEERING INSIGHT

When a spin-off of Finnish firm Nokia had the idea to develop a new type of multifunctional digital camera for clinical diagnostic procedures, they enlisted the help of optical specialist Wild GmbH (Völkermarkt, Austria). With more than 35 years of experience in the field of optomechatronics, the Austrian company has substantial experience in the fields of technical optics and medical technology.

The instrument is designed to offer much greater imaging capabilities than the manual instruments traditionally used by general medical practitioners. The camera can image the skin, inner ear, retina and other parts of the eye to detect conditions such as melanoma, ear infections, damage to the eardrum, glaucoma, and macular degeneration. Its multifunctionality is made possible by ophthalmoscopic, otoscopic, and dermatoscopic lens attachments. Thanks to a simple bayonet closure, the lenses are easy to exchange.

Overcoming Obstacles

Owing to the limited amount of space in the auditory canal, it can be difficult to illuminate and record images of the inner ear at the same time. A similar problem arises when imaging the inside of the eye, which can be further complicated because high levels of light can cause the pupil to contract. In addition, lighting used for diagnostics can create glare that interferes with imaging. One of the main challenges in designing the device therefore was developing a camera that could provide clear images using limited amounts of light. In the end, the company chose to use photoconductors and autofocus functionality to help accomplish this.

Determining an appropriate image resolution was also a challenge because the higher the resolution is, the darker the resulting image will be. Wild GmbH found a compromise by which both resolution and brightness were sufficient to create a clear image suited for diagnostic purposes.

Imaging skin with the device was not without its own challenges. Dermatologists frequently use glass plates to press the area of skin flat for it to be examined. A so-called immersion fluid is applied between the skin and the glass plate, which causes the uppermost layer of skin to appear transparent, enabling more details to be detected. But the glass plate also can cause reflections that can im­pair image quality. Wild GmbH used a computer-optimized reflector and a special arrangement of light sources to obtain bright, clear, reflection-free images.

Available from between € 2000 and € 5000, the camera is designed to perform similarly to floor-mounted imaging systems costing approximately € 30,000, according to the firm. Project director Peter Reiter believes that, because of its advanced imaging and relative affordability, the camera could revolutionize the diagnostic capability of hospitals and clinics in third-world countries. “Our product could lead to a massive reduction of deaths due to diseases of the eye and skin,” he says. Reiter explains that the high-quality images greatly improve the accuracy of diagnosis, which can help make early detection of diseases possible.