Medical spectrometer with electro-optical circuit board
An electro-optical spectrometer has been miniaturised so that it can be used in the confined spaces of an intensive care unit. The device monitors vital parameters in the patient's brain. It utilises a combined circuit board for electrical and optical signals.
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Initial situation
Space is at a premium in an intensive care unit. The electro-optical device for monitoring vital parameters in patients' brains was as big as a control cabinet. Now it had to be
to the size of the palm of a hand and meet medical standards. -
SCS solution
Luciole Medical develops and markets a brain monitoring platform that monitors cerebral blood flow and oxygen metabolism.
Together with Luciole Medical, SCS has developed the miniaturised electro-optical spectrometer RheoControl. It contains four lasers, optical fibres, electrical detectors and an FPGA for control and communication with the medical computer. -
Added value
The new spectrometer takes up only a fraction of the space of the original device.
Multiple devices can be stacked to monitor vital parameters at multiple locations in the brain. They synchronise with each other.
The spectrometer complies with medical standards and has been used in hospitals since 2017.
Project insights
Brain injury is a leading cause of death and lifelong disability worldwide and one of the most common causes of admission to neurological intensive care units (ICU). Bedside real-time monitoring of vital brain parameters such as cerebral blood flow (CBF) and brain tissue oxygen saturation (SbtO2) enables medical staff to recognise warning signs early and make informed treatment decisions to protect patients from secondary brain damage.
Luciole Medical has developed a bedside neuromonitoring system that can reliably measure vital brain parameters. However, the device was installed in a trolley the size of a control cabinet. Far too big for an intensive care unit or operating theatre. They wanted to shrink it down to the size of a small box, about the size of a hand.
The solution
Luciole Medical and SCS, together with the University Hospital Zurich, the University of Zurich and ETH Zurich, have developed RheoControl: a miniaturised, laser-based neuromonitoring spectrometer. In principle, it measures the absorption of 4 infrared laser sources by haemoglobin or by a fluorescent dye injected into the brain. The spectrometer is portable, CE-certified and fully controlled via the USB interface.
Key technologies
The miniaturisation of the RheoControl unit was achieved through the use of waveguide technology. This makes it possible to combine the light from four laser diodes in a precise and economical process. The fibre-coupled and combined output light can be connected to one of the two types of Luciole’s brain sensors.
The main board consists of an analogue front-end stage, a field programmable gate array (FPGA), which controls the power and timing of the laser diodes and transmits the measurement data to the medical computer via the USB interface. A separate laser protection circuit ensures eye-safe operation of the system.
Medical development process
The spectrometer is a class IIa medical device. The main challenges are compliance with the regulations for medical devices, laser safety (laser class 1M) and electrical patient protection (4 kV). The most important development steps included a risk analysis, risk minimisation and FMEDA.
RheoControl supports both a minimally invasive probe, RheoSens, which measures intracranial pressure, brain temperature, cerebral oxygen metabolism and cerebral blood flow, and a non-invasive patch, RheoPatch, which measures cerebral oxygen metabolism and cerebral blood flow.
SCS contributed to the project with requirement engineering, system design, development of hardware, firmware/software, calibration tools, certification process and CE-compliant labelling in production.
The spectrometer has been used successfully in hospitals since 2017.