SCHOTT solutions no. 1/2009 > Fiber Optics

Photo: MBR Optical Systems

Revolution in Medical Technology

Thanks to a unique new measurement technique, blood test results can be obtained non-invasively in the future. Highly precise fiber optic light conductors from SCHOTT play a key role.

Christoph Hadnagy

It sounds like a scene from a science fiction movie: While giving first aid to an injured person, a paramedic holds a sensor next to that person’s arm for a short moment. Seconds later, an exact analysis of the most important blood parameters is shown on a display – free of pain and without having to draw blood. These values are immediately sent to the hospital, where the appropriate measures can be initiated without delay. What sounds like a vision for the future is actually very real. Based in Wuppertal, Germany, MBR Optical Systems has developed a unique device in recent few years that represents a revolution in the area of medical measurement technology. The instrument called “Haemospect” was introduced to the public at the world’s largest medical exhibition “Medica” in Düsseldorf in 2008. The measuring principle is ingeniously simple, yet very complex. It is based on the analysis of the spectral characteristics of blood components. This allows for incredibly exact measurements to be made of the hemoglobin value that is of relevance to the oxygen content in blood or for vasomotion, in other words the inherent movements of the capillary vessels in transporting blood. The physicist and mathematician Holger Jungmann and the physician Michael Schietzel have been working on a solution for measuring blood with the help of light already since the beginning of the 1990s. This not only makes it much easier to obtain measurement values, it also lowers the risk of infection.

The main pieces of “Haemospect” include fiber optic light conductors that are manufactured by SCHOTT Lighting and Imaging. A sensor head placed on the skin projects a white light into the underlying tissue via a waveguide. Some of the projected light is absorbed by the various components of tissue, much like a defined fingerprint, while some of it is reflected. This method is referred to as reflection spectrometry. Another waveguide transmits the light reflected as a result of the physical conditions back to the device. Then, a spectrometer breaks the light down into its separate wavelengths and an electronic evaluation unit connected to the system analyzes it. The resulting data is then processed using an algorithm developed by MBR and visualized on the display of the device in the form of quantitative values.
Apply the sensor, that’s it ! “Haemospect” painlessly measures blood values directly through the skin. Photo: SCHOTT/A. Sell
The demands placed on the fiber optic components are complex. “With medical applications, biocompatibility is the main catchword,” explains Florence Buscke, Sales Manager for the product group Medical at SCHOTT Lighting and Imaging. This means that none of the materials used are allowed to have negative effects on an organism. In the area of fiber optics, this is a relatively easy problem to solve, unlike the other materials that are needed. “Many of the traditional polymer and adhesive materials with which we join the light conductors with the head of the sensor, for example, either do not meet these demands or do not fit in well with the final product from an esthetic standpoint. For this reason, we had to find substitutes in a short time,” says Florence Buscke in providing insights into the challenges of the development process. The stability of the fiber optic light guides is yet another important criterion for quality. Even the slightest deviations and damages to the material would make correct measurement impossible. For this reason, a great deal of importance is placed on durability and reliability. However, SCHOTT still succeeded in developing and manufacturing the right solution in only a few months. Dr. Holger Jungmann, one of the developers of the “Haemospect” hand probe and a partner in MBR Optical Systems, also praised the collaboration: “By involving all of the important areas – from design to construction and quality control – the development process went very quickly and remained quite flexible,” the physicist explains. The possibilities that this hand-held measurement device offers are plentiful. In addition to obtaining other blood test results in adults, the focus is also on developing special devices for quick and easy examination of newborns and premature babies, as well as in prenatal diagnostics. Other treatment fields include the treatment of fire victims, monitoring bypass operations or skin and tissue transplantations. <|