Guoqiang Yu, an associate professor in the Center for Biomedical Engineering, has devoted years of research to developing novel diffuse optical devices that can noninvasively measure the blood flow, oxygenation and metabolic rate of a tumor. By placing a foam pad containing several optic fibers onto a patient’s neck to establish contact, doctors can learn critical information about the head and neck tumor, whether its aggressiveness or the effectiveness of the radiation treatments. When scanned using Yu’s device, the vasculature of the tumor can reveal a noticeable difference in blood flow and oxygenation when compared to non-tumorous tissue.
“Radiation doesn’t only destroy the tumor cells, but it also causes many side effects throughout the body,” Yu explains. “Because we can monitor changes in the tumor more safely, easily, continually and less expensively than with magnetic resonance imaging (MRI) or computed tomography (CT), we can give clinicians timely feedback on whether the treatment is effective.”
While Yu’s scanner has shown success when measuring neck tumors, which are hard and allow for evenly distributed contact, a system relying on contact probes may not be effective when attempting to measure tumors in soft breast tissue or pressure ulcers. Probe contact on ulcer tissue can cause infections and, because breast tissue is soft, it is nearly impossible to consistently apply the right amount of pressure and achieve even coverage of the tumor.
So how can one collect the measurements typically provided through a contact probe system without applying pressure to the tumor or affected area? Yu’s solution has been to develop a non-contact probe device that yields blood flow, oxygenation and metabolic rate measurements without ever touching the skin.
“We have developed a prototype that we are adjusting based on our early testing and have published one paper on using the non-contact probe to measure blood flow,” says Yu. “Our goal is to take our findings, show funding agencies that we can accomplish something no one has ever done before in creating a non-contact probe to functionally image tumors and then get the product to the market.”
While Yu has seen success in early experiments using the device, unanticipated technical challenges have required him and his graduate students to make adjustments.
“What we have discovered is that even subject’s breathing can alter the readings, something that doesn’t occur with contact probes on neck tumors,” he recounts. “Also, simple things like room light can affect the scan and distort the measurements.”
The need for such a device, which has potential to substantially increase the percentage of breast cancer survivors, as well as minimize debilitating side effects of treatment, is immense. Yu is eager to meet the need.
“From early detection of breast tumors or pressure ulcers to frequent, inexpensive monitoring of treatment effectiveness, a non-contact probe system can significantly advance the way we diagnose and treat them.”
For more information on Guoqiang Yu’s Biomedical Optics Lab, visit http://bioptics.engineering.uky.edu/.