IMPORTANCE Face paralysis remains one of the most challenging conditions to

IMPORTANCE Face paralysis remains one of the most challenging conditions to successfully manage often leading to life-altering deficits in both function and appearance. Individuals 24 healthful volunteers. MAIN Final result MEASURE Video-quantified blinking was weighed against both IR sensor indication magnitude and price of transformation in healthy individuals using their gaze in repose while they shifted gaze from central to far peripheral positions and during the production of particular facial expressions. RESULTS Blink detection based on signal magnitude achieved Pifithrin-beta 100% sensitivity in forward gaze but generated false-detections on downward gaze. Calculations of peak rate of signal change (first derivative) typically distinguished blinks from gaze-related lid movements. During forward gaze 87 of detected blink events were true positives 11 were false positives and 2% false negatives. Of the 11% false positives 6 were associated with partial eyelid closures. During gaze changes false blink detection occurred 6.3% of the time during lateral eye movements 10.4% during upward movements 46.5% during downward movements and 5.6% for movements from an upward or downward gaze back to the primary gaze. Facial expressions disrupted sensor output if they caused substantial squinting or shifted the glasses. CONCLUSION AND RELEVANCE Our blink detection system provides a reliable noninvasive indication of eyelid closure Pifithrin-beta using an invisible light beam passing in front of the eye. Future versions will aim to mitigate detection errors by using multiple IR emitter/detector pairs mounted on the glasses and alternative frame designs may reduce shifting of the sensors relative to the eye during facial movements. INTRODUCTION Facial paralysis affects up to 0.3% of the population every year in Western Europe and the United States.1 People usually experience unilateral facial paralysis with preserved contralateral facial movement. One of the most bothersome issues is loss of vision blink due to paralysis of the orbicularis oculi muscle around the affected side. The perpetually Mouse monoclonal to SARS-M open vision is at risk for exposure to debris and drying and results in chronic irritation and pain. Additionally the loss of vision blink may lead to permanent corneal damage from ulceration or contamination. Aside from the functional impairment in blinking and other facial movements facial paralysis is also a major psychological barrier to a healthy social life and low thresholds for observer detection of blink asymmetry have been exhibited.2 3 One possible way to restore blink is through a closed-loop neural prosthesis (facial pacing device) that detects normal blinking on one side of the face and simultaneously stimulates blinking around the paralyzed side. Since blinking is typically symmetrical the healthy vision blink may serve as an appropriate trigger for prosthetically-assisted blink around the contralateral side in facial paralysis. One of the challenges in using healthy blinking as a trigger for induced blinking in facial palsy is usually to rapidly and accurately detect healthy blinks in a noninvasive and non-disruptive manner. The most frequently proposed method for non-invasively detecting blink around the intact side is through skin surface electromyographic (EMG) recording of the orbicularis oculi muscle4-7 followed by detection of periocular tissue movements through gyroscopes8 or accelerometers.9 Although these approaches demonstrate promise for accurately detecting blinks they require placement of sensors on the face surface which complicates device use and potentially influences dynamics of healthy blinks. We have developed a novel approach to eye blink detection utilizing infrared (IR) emission/detection as a safe noncontact invisible and inexpensive indicator of Pifithrin-beta eyelid Pifithrin-beta closure over the eye. Our prototype system employs an IR light-emitting diode (LED) and an IR detector mounted on a pair of glasses. The LED and detector components are positioned at the nasal and temporal aspects of one eye causing the infrared beam to pass horizontally across the central portion of the palpebral fissure just anterior to the corneal surface (i.e. the pupil location when looking straight Pifithrin-beta ahead). The beam remains unbroken when the eye is open but is interrupted by the eyelashes and/or lid tissue when the upper lid descends causing the circuit receiving the IR.