WPI Research is the research magazine of Worcester Polytechnic Institute. It contains news and features about graduate research in the arts and sciences, business, and engineering, along with notes about new grants, books, and faculty achievements.
Issue link: http://wpiresearch.epubxp.com/i/90696
the same basic idea employed in the pulse oximeters that are clipped onto hospital patients' fingers to measure blood oxygen levels, but taken to a far more sophisticated level. Proof-of-concept studies with healthy patients donating blood have shown the light-based sensor system can detect early signs of a reduction in blood volume. Chon and Mendelson speculate that the same system may also be able to detect dehydration in patients not suffering from blood loss. In addition to the wearable sensors, the WPI team will adapt the technology for use on a smartphone, with the built-in video camera providing light and then recording the reflections for processing. The UMass Medical team will develop decision-support tools to be embedded in the smartphone application, so when the device is deployed in the field it will not only measure vital signs, but also prompt the medic or civilian first-responder with information to guide treatment. The blood loss sensor project, one of many collabora- tions ongoing between faculty at WPI and the University of Massachusetts Medical School, highlights the value of bringing engineers and clinicians together. "Having the opportunity to collaborate with the trauma team at UMass Medical is extremely important for our work," Mendelson says. "This is not a case of our developing the technology and handing it over for their use. It is a collaborative pro- cess. The physicians' clinical understanding and experience helps us refine the technology." Helping Physicians Target Cancer With cancer, early detection is often the key. The sooner a malignancy is found and characterized, the better the chances are for effective treatment. For many cancers, a needle biopsy is the first invasive step in the diagnosis, but results can be inconclusive when the targeted tissue is small or otherwise difficult to access through the skin. Researchers at WPI are helping to improve those odds by developing a robotic system that will allow doctors to  precisely position a biopsy needle as it is guided by live MRI images. The system, designed to work inside the bore of an MRI machine, will soon be tested in a clinical trial at Brigham and Women's Hospital (BWH) in Boston. "Our first clinical goal is to improve the efficacy of needle biopsies for prostate cancer diagnosis, but we know there are many other applications for this technology," says Gregory Fischer, assistant professor of mechanical engineering and director of the Automation and Interventional Medicine (AIM) Lab at WPI. "The system gives a surgeon real-time images and the control to move the needle through and around tissues in ways that cannot be done so accurately by hand and without image guidance." To build a robot capable of working within the small confines and intense mag- netic field of an MRI machine, Fischer and the AIM team had to use materials without ferrous metal parts and with components designed to not emit electrical signals that could interfere with the quality of MRI images. Years of testing and development have yielded a system composed of specialized robot control electronics, fiber-optic sensors, ceramic piezoelectric actuators, engineered robot modules, and other components that are compatible with the MRI environment. Fischer worked closely with the Advanced MRI Center at UMass Medical School in Worcester to test prototypes of his robotic system using tissue analogues and non-human biologic samples. "We have answered the tough engineering questions," Fischer says. "The system works. We can put a needle or a probe wherever the surgeon wants it." In addition to the needle biopsy trial, Fischer and his colleagues at BWH hope to use the system for prostate brachytherapy, which is the placement of small radioactive particles within tumors to kill the cancer. Colleagues at Harvard Medical School are testing one of Fischer's systems for kidney cryoablation. Fischer is also working with a med- ical device company that builds high-energy ultrasound systems that ablate cancer cells. They are planning to adapt wpi.edu/+research