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Biomedical System for Monitoring Pressure Ulcer Development

— filed under:

  • PhD Defenses
When Apr 11, 2013
from 12:00 PM to 01:30 PM
Where Engr. IV Bldg., Faraday Room 67-124
Contact Name
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Frank Tinghwa Wang

Advisors:  Professors William Kaiser and M.-C. Frank Chang



Pressure ulcers (PU) are one of the leading health concerns among patients living in long-term care facilities and are a common occurrence in hospitals. In the United States alone, over 2.5 million patients will suffer from pressure ulcers each year, with over 60,000 deaths attributed to pressure ulcer related complications. The cost to treat pressure ulcers including hospitalization costs is also prohibitively expensive; just in the United States alone it is estimated that $9.2-15.6 Billion dollars are spent annually on pressure ulcer treatments.

Pressures ulcers are often preventable if the symptoms are detected early enough, yet the monitoring of skin integrity and pressure ulcer has always relied on a direct visual inspection, which has been shown to be unreliable especially for patients with darkly pigmented skin. As such, there is an urgent need for a handheld medical device to detect and monitor the early symptoms of pressure ulcer development.

The SEM Scanner was developed to address this urgent need.  The SEM Scanner is a smart compact capacitive sensing wireless handheld system which measures sub-epidermal moisture (SEM) as a mean to detect and monitor early symptoms of pressure ulcer development. The wireless handheld unit incorporates an array of bio-compliant flexible Kapton electrodes which are excited to measure and scan the SEM in a programmable and multiplexed manner. The SEM Scanner is also wirelessly enabled; allowing patient data to be wirelessly uploaded through a gateway to a remote server, where patients skin integrity can be tracked and monitored over time.

The efficacy of this system was verified through three IRB-approved clinical trials. Combined, over 100 patients participated in these trials. In one of the trials, the SEM scanner was able to accurately predict the onset of PU 1.5 days prior to the visual detection of pressure ulcer symptoms in 70% of the cases.

Expanding upon the success of the SEM Scanner, a next generation device was designed to provide spatial imaging of SEM. This device, called the SEM Imager utilizes a novel electrode array to maximize the spatial resolution. Instead of using concentric rings as used on the SEM scanner, the SEM Imager uses an array of hexagon pads, where each pad can be programmatically reconfigured for different electrode geometries. With this architecture, the electrode geometry is not limited to concentric rings, but can be of any arbitrary shape. The SEM Imager has been shown to positively image areas of tissue with higher moisture content in a healthy subject trial.


Frank Wang is a Ph.D. candidate in UCLA’s Electrical Engineering Department, conducting research with the UCLA Wireless Health Institute.  He earned his B.S. degree in Electrical Engineering and Computer Science from University of California, Berkeley, and his M.S. degree in Electrical Engineering from the University of California, Los Angeles.  His research interests are primarily focused on inventing enabling technologies to make breakthroughs in healthcare.


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