Graduation Semester and Year




Document Type


Degree Name

Master of Science in Biomedical Engineering



First Advisor

Hanli Liu


Pain is a sensory and emotional experience as a result of possible or definite tissue damage. The level of pain is subjective to the individual's consciousness of sensory stimuli. Pain stimuli can be noxious (i.e., potentially damaging) or innocuous (i.e., normally not painful). Therefore, pain perception can be based on the degree of the stimuli. Studies have been done using brain imaging modalities to assess pain. Functional Near-infrared spectroscopy (fNIRS) is a noninvasive imaging tool and has been used to study the hemodynamic variations in the brain induced by a variety of activations. This research was a feasibility study to implement a Pressure Pain Generator (PPG) and test its success in creating controlled pain at an intensity that can be associated with the hemodynamic measures by fNIRS. First, the PPG was built and calibrated, demonstrating its feasibility in creating mechanical pain through pressure-voltage relationship. Second, the calibrated PPG was used with a human subject to rate pain from low to high level using the visual analog pain scale. The subject could differentiate different degrees of mechanical pain as the voltage was varied. Third, PPG was utilized in conjunction with an fNIRS brain imager to study hemodynamic responses in the prefrontal cortex area when two levels of pain were induced by the PPG. The results of fNIRS were used to correlate the hemodynamic response with the intensity of the pain stimuli. The results revealed significant changes in concentration of oxygenated hemoglobin during post-stimulation in the prefrontal cortex area. It is clear that the PPG can generate well controlled pain stimuli, which can also be evaluated by fNIRS for pain perception. This feasibility study demonstrates a methodology that can be used to understand the hemodynamic response to pain and correlate it to the perception of pain.


Biomedical Engineering and Bioengineering | Engineering


Degree granted by The University of Texas at Arlington