|A hyperspectral imaging system based on DLP chip technology can provide real-time mapping and visualization data to surgeons to reduce the risk of complications.|
By applying an optical semiconductor technology commonly used in digital color projectors to an imaging technique employed by the defense industry, Karel Zuzak, senior biomedical research engineer at Digital Light Innovations (Austin, TX), has shed light on an array of potential optical medical imaging applications. The resulting hyperspectral imaging system could help reduce the risk of complications during various medical procedures and associated liability.
Providing chemical information about an imaged object, hyperspectral imaging entails the collection and processing of data from across the electromagnetic spectrum. Although proven useful in military air surveillance and other sectors, this particular ability to obtain information based on chemical data had not previously been explored in terms of potential medical applications. "The National Institutes of Health (NIH) had an interest in applying technology that had been used for defense to medical applications," Zuzak says. "It is of interest for using taxpayers' hard-earned money toward technology that is used to defend the nation as well as to bring better health to everyone."
Tasked with this ambitious research mission as a postdoctoral fellow at the NIH, Zuzak was able to develop a hyperspectral imaging technology using off-the-shelf components and by figuring out the math required for doctors to see better in the body. At the heart of the system, however, is the Digital Light Processing (DLP) development kit from Texas Instruments (Dallas), which features a DLP chip, software, and board electronics. Consisting of an array of tiny micromirrors mounted on a hinge that rocks back and forth like a seesaw, the DLP chip technology serves to control the different rainbow of colors in light or the spectrum in order to illuminate objects and determine their chemical composition, according to Zuzak.
"The DLP hyperspectral imaging method is a reflectance measure," Zuzak explains. "What this system does is actually illuminate a patient's tissue and collect information that is reflected back." Unlike the multispectral imaging technology at the heart of pulse oximeters, for example, the DLP hyperspectral imaging system does not require physical contact with the patient to gather information, Zuzak states. In fact, he adds, it can capture an image from a far-off distance or from mere inches away; however, a distance of two feet is typical. This ability is advantageous because the system does not need to compromise a sterile surgical area. In addition, it obtains chemically encoded images at a near-video rate of about four frames per second.
As a result, the platform-like imaging technology can provide real-time mapping and visualization data to assist surgeons with performing difficult procedures. Recent changes to reimbursement policy related to complications during gallbladder surgery, for instance, have created an increased demand for tools that help to reduce risk, according to Zuzak. Catering to this need, the DLP hyperspectral imaging system can act as an anatomical GPS of sorts, helping the surgeon to better navigate inside the body to avoid complications and risks.
"Surgeons are experts in anatomy from the textbook, which is the ideal case. But we're all different, and sometimes the vasculature just isn't laid out nicely; [vessels] will be twisted around each other, and the structures are embedded in connective tissue and fat," Zuzak notes. "Being able to identify the anatomical structures based on their chemical composition rather than just appearance is helping surgeons to see better inside the body."
In addition to aiding in gallbladder surgery, hyperspectral imaging technology is suited for a multitude of medical applications, including tissue oxygenation monitoring, wound healing, drug therapy monitoring, laparoscopic video imaging, noninvasive optical biopsies, diabetic retinopathy, retinal imaging, postoperative care, and personalized medicine. Zuzak and Digital Light Innovations are currently seeking OEM partnerships for implementation and commercialization of the technology into such applications.