NewScITech

Patients with sleep disorders will soon be able to undergo medical examinations at home: Vital physiological functions are monitored by a “portable sleep lab”, which transmits the data directly to the physician.Sleep disorders are common in the industrialized world, but it is often difficult to identify the reason. Anyone who wants to find out why they are sleeping so badly has only one recourse: an overnight stay in a sleep laboratory, where up to 24 vital parameters are monitored during the night, including the patient’s breathing pattern, sleeping position, blood oxygen concentration, and the brain (EEG), heart (ECG), eye (EOG) and muscle (EMG) functions. These data allow the underlying cause of the disorder to be diagnosed and an appropriate treatment to be prescribed. The complex differential diagnosis that this involves makes a visit to the sleep laboratory a costly affair – quite apart from the discomfort to the patient of being tied up to innumerable sensors and wires, an unnatural situation that could falsify the measurement results.

The Fraunhofer Institute for Integrated Circuits IIS has developed a low-cost, patient-friendly alternative in collaboration with industrial and clinical partners. The “portable sleep laboratory” was unveiled to the public at the Medica trade fair in Düsseldorf on November 15-18 (Hall 10, Stand F05). The novel monitoring instrument can be strapped on unassisted by patients at home, and does not restrict their freedom of movement. Only four sensors are needed to collect data on sleeping position, pulse rate, heartbeat and blood oxygen concentration. Christian Weigand, who heads the IIS research group for medical communication and sensor systems, confirms that this is sufficient to produce a diagnosis of equal quality to that obtainable from a conventional sleep laboratory: “We have observed more than 50 patients under the usual sleep laboratory conditions, who at the same time were connected to our device. In this way, we were able to collect two sets of data and compare the results.”

The “bedside sleep laboratory” is strapped to the patient’s chest and transmits the recorded data over a standard wireless Bluetooth connection to a local base station in the patient’s home. This terminal automatically processes the data and transmits them via a custom-designed server over a secure, encrypted link to a terminal in the doctor’s office. The device is currently being tested at the university hospitals of Marburg and Nürnberg on a total of 30 sleep-disorder patients. Meanwhile, Christian Weigand is sufficiently confident to embark on a second stage: “We are working on a device that can operate with even fewer parameters, for instance just the ECG”.

Fraunhofer-Gesellschaft