Timing of the intervention for intracranial hematomas is critical for its success, specifically since expansion of the hemorrhage can result in debilitating and sometimes fatal outcomes. Led by Britton Chance, we and an extended team from University of Pennsylvania, Baylor and Drexel universities developed a handheld brain hematoma detector for early triage and diagnosis of head trauma victims. After obtaining de novo Food and Drug Administration clearance, over 200 systems are deployed in all Marine battalion aid stations around the world. Infrascanner, a handheld brain hematoma detection system, is based on the differential near-infrared light absorption of the injured versus the noninjured part of brain. About 12 independent studies have been conducted in the USA, Canada, Spain, Italy, the Netherlands, Germany, Russia, Poland, Afghanistan, India, China, and Turkey. Here, we outline the background and design of the device as well as clinical studies with a total of 1293 patients and 203 hematomas. Infrascanner demonstrates high sensitivity (adults: 92.5% and children: 93%) and specificity (adults: 82.9% and children: 86.5%) in detecting intracranial hematomas >3.5 mL in volume and <2.5 cm from the surface of the brain. Infrascanner is a clinically effective screening solution for head trauma patients in prehospital settings where timely triage is critical.
Transcranial magnetic stimulation (TMS) is a noninvasive method used to excite or inhibit cortical activity for experimental, diagnostic, and therapeutic interventions. However, nonmotor regions of the brain targeted in TMS therapies, such as the dorsolateral prefrontal cortex (DLPFC), offer no extrinsic response to stimulation, resulting in a need for a practical method for the evaluation of treatment. We sought to determine the capability of a continuous-wave light emitting diodes (LED)-based functional near-infrared spectroscopy (fNIRS) system to measure evoked cortical hemoglobin changes in the DLPFC during the simultaneous application of TMS to the left-DLPFC under brief stimulation paradigms used in the clinic. Seventeen healthy participants received short TMS trains at F3 in four different stimulation conditions (single pulse, high frequency, intermittent theta burst, and sham) while adjacent fNIRS measurements were recorded. Ten 2-s trains of each stimulation type were delivered with an intertrial interval of 40 s. Results indicated that high-frequency stimulation produces a larger and more evident response than other measured conditions. These findings show that a continuous-wave LED-based fNIRS system can be used to measure TMS-evoked responses and that future TMS applications can benefit from concurrent assessment of localized cortical activation changes.