The leading cause of long-term disability in Europe and the United States is ischaemic stroke. Despite the success of the currently used treatment, recombinant tissue-type plasminogen activator (rtPA), about half of all patients suffer morbidity. Surgeons need immediate information on whether new paths have been created at the site of the clot, a process called recanalisation. The 'Diffuse-optical monitor of cerebral hemodynamics after rtPA administration in acute ischemic stroke' (RTPAMON) project brought together biomedical physicists and clinical neurologists to develop appropriate equipment. The researchers developed three generations of monitoring equipment. Positive results from the first established the range of healthy cerebro-vascular reactivity (CVR) index in healthy volunteers. RTPAMON compared diffuse optical measurements with those of the transcranial Doppler ultrasound instrumentation. The second phase corrected the problems apparent in the first phase from feedback. Studies using the second generation have compiled data on changes in the CVR due to lesions in carotid arteries and again compared them with healthy individuals. There were significant differences in micro- and macro-vascular response. As the second generation device is available for use in hospitals, RTPAMON have trained the collaborating neurologists in its use. The doctors collected data from a group of patients during the initial emergency room management that included administration of rtPA. Development of the third generation machine led to the formation of a spin-off company, HemoPhotonics. The new set-up will commercialise the technology for a variety of applications.
Ischaemic stroke, rtPA, recanalisation, monitoring equipment, cerebrovascular reactivity index, Doppler