April 22, 2026 | It is notoriously difficult to detect ovarian cancer early, particularly aggressive high-grade serous types that often originate as precursor lesions in the fallopian tubes. The cancer quietly spreads at a microscopic level within the abdomen, defying discovery until symptoms emerge in advanced stages of the disease when it becomes hard to treat and difficult to cure.
Colon cancer has a similar story, which starts as harmless polyps that grow into tumors over many years without causing symptoms and when left undiagnosed and untreated eventually progress into malignant tumors. But, unlike ovarian cancer, it has a highly effective screening tool that can prevent cancer by removing precancerous polyps, according to Dominique “Nikki” Galvez, Ph.D., who spent her doctoral years at the University of Arizona working on endoscopes designed to detect precursor lesions in the fallopian tubes.
The cell-acquiring fallopian endoscope (CAFE) is sub-millimeter medical device capable of making the journey through the tight and winding fallopian tubes to capture optical signals and cytology samples associated with early disease, as covered in her capstone paper that was published recently in Biophotonics Discovery (DOI: 10.1117/1.BIOS.3.2.025001). It’s a flexible instrument purpose-built for real-time internal visualization and diagnostic sampling, but that’s where the similarities with a colonoscope end.
The anatomical characteristics of the fallopian tubes demand a built-from-scratch technology accommodating an environment where the inner diameter is less than a millimeter and can collapse around the device, she explains. CAFE performs multispectral tissue analysis using a high-density fiber bundle and a custom close-focus lens to maintain sharp images at extremely short distances.
Optically, the device combines white light imaging for navigation and to reveal structural features and small blood vessels with blue light reflectance and fluorescence imaging to probe tissue properties. CAFE also includes a working channel for “scoop” style cell collection directly into the endoscope tip to reduce the risk of tissue injury.
The long-term goal is a screening device for women with a predisposition to ovarian cancer, notably those with a BRCA1 or BRCA2 genetic mutation, says Galvez. A bilateral salpingo-oophorectomy, meaning total removal of both ovaries and fallopian tubes, is typically advised for high-risk women.
While generally considered safe, the surgery comes with bleeding and infection risks and has long-term health consequences related to the abrupt loss of ovarian hormones that can be substantially greater for women who undergo the procedure before natural menopause, she notes. By using CAFE as a screening device, such women might one day have the alternative of a minimally invasive procedure to quickly determine the presence of early signs of trouble while allowing them to hold onto their ovaries for as long as possible.
CAFE is a developing technology and the result of decades of work in the lab of Jennifer Barton, Ph.D., biomedical engineering professor at the University of Arizona and director of UArizona’s BIO5 Institute. It is a direct evolution of earlier research prototypes and falloposcopes intended to search for signs of early-stage ovarian cancer. The targets are abnormal cells that alter the metabolism, tissue structure, and blood supply of their surrounding environment as they develop, thereby affecting how light gets reflected and emitted.
Galvez was a Ph.D. student of Barton’s and only recently transitioned to a position with Ansys, part of the engineering simulation software company Synopsys with many tools for optical simulation. The two first met because of a STEM class assignment to write a bio on a woman working in the optical sciences at the university.
“I was totally blown away because I didn’t know there was a biomedical aspect to optics,” says Galvez, who initially intended to study holograms. After firing off an email to Barton in a quest to learn more, Galvez was invited to apply her optics and electrical engineering know-how to help further development of the cancer-seeking device.
Previously developed endoscopes have used microbrushes to blindly collect cells from the fallopian tubes for purposes of diagnosing conditions that affect fertility, says Galvez. Different specialized instruments were then used to remove any tubal occlusions. “They never really incorporated the optical aspect; that’s what’s special about our device.”
CAFE represents the latest iteration of the technology, effectively turning the falloposcope into a device that optically highlights potential precancerous sites within the fallopian tubes, and collects suspicious cells to confirm the presence of a precancerous lesion. Along with fluorescence imaging, earlier endoscopes used optical coherence tomography (OCT), which is analogous to a light-based ultrasound, for seeing structural differences inside the walls of the fallopian tubes, she says. Instead of OCT, the redesigned version explores the cell-collection method, to take advantage of the target precancerous lesions’ distinct molecular signature.
Performance of CAFE was initially evaluated on intact and benign ex vivo fallopian tubes removed during surgery from three patients at New York Presbyterian Queens Hospital. A pilot in vivo study of the device is now underway at Banner – University Medical Center Tucson on women scheduled to have their tubes removed during surgery.
For many of the Ph.D. students who have successively worked in Barton’s lab, including a young man whose mother had ovarian cancer while pregnant with him, the drive for answers is personal. Dealing with tiny optics and lenses can be physically painful, but as he has aptly pointed out, the suffering pales in comparison to that endured by people with cancer, says Galvez.
It has been a little over a decade now since many types of ovarian cancer have been hypothesized to originate in the fallopian tubes as precancerous lesions before developing into cancer over the course of several years, Galvez says. Evidence quickly emerged that high-grade serous ovarian carcinoma, which make up most epithelial ovarian malignancies, usually starts in the fallopian tubes.
Biomedical and optical engineers at the University of Arizona wasted no time in leveraging that knowledge to build an anatomically-suitable endoscope. The “chip-on-tip” technology of modern colonoscopes, which combined an objective lens and a complementary metal-oxide-semiconductor (CMOS) imaging sensor at its distal tip along with bright LED lights, is simply too big, as of now, for the relatively confined space within the fallopian tubes, she explains. This is how digital signals get captured and transmitted to an external video processor as the long, flexible tube navigates the curves of the colon.
In lieu of the CMOS sensor, the redesigned endoscope features a flexible fiber bundle comprised of 10,000 pieces of rod-shaped glass fibers about 2 microns in diameter where each fiber acts as a single pixel in the image, Galvez continues. The fibers collectively serve as a temporary sensor, transmitting the signal from one side of the bundle to the other outside of the body to the control rack of the endoscope, where lenses focus the image of the fiber bundle onto the actual camera sensor.
The fiber bundle also presents a lot of physical constraints due to its stiffness and imaging constraints as it suffers from “honeycombing,” a well-known issue with this type of imaging, says Galvez. It’s a noise pattern that appears as a superimposed grid-like structure on the final image.
Among the other design challenges with this micro-endoscopic application was devising the objective lens, she adds. Compared to gradient refractive index (GRIN) rod lenses typically used in micro-endoscopes, Galvez previously tested 3D-printed lenses using a “two-photon polymerization” process providing the design degrees of freedom typical, or even exceeding, that of larger, more commonplace optical systems. Although the close-focus GRIN lens chosen for the CAFE performed better than the additive manufacturing approach, Galvez says she believes 3-D printing is the next frontier in micro-endoscopy given constant advancement in the field she witnessed just during the multi-year endoscope project.
Safety is of course a key concern when utilizing the CAFE in patients, says Galvez. The development teams must ensure the CAFE meets the American National Standard Institute’s (ANSI) standards, she says, meaning that the light being delivered to the tissue is radiometrically safe and won’t cause thermal injury. All the component materials also need to be biocompatible to avoid triggering immune responses, inflammation, or toxicity, and the cell collection feature can’t cause injury to the epithelial surface of the fallopian tubes.
How to comfortably insert the device into the body also needs to be nailed down before it would be suitable for clinical outpatient use, says Galvez. Currently, this is done under general anesthesia because device testing is on women undergoing a salpingo-oophorectomy. A hysteroscope is used to enter the vaginal canal to get to the uterotubal ostia, the pinhead-sized openings at the lateral upper corners of the uterine cavity where the fallopian tubes meet the uterus.
Patents are held by the University of Arizona, and Barton is the listed inventor on the falloposcope technology. A commercialization partner is currently being sought.