A key part of a medical patient’s physical examination is performed through touch, but the doctor can only glean so much information from what he feels. That’s why Temple University researchers have created a prototype device that will not only emulate human tactile sensation, but quantify it as well.

The tactile imaging sensor has been developed by Chang-Hee Won, an associate professor of electrical and computer engineering at Temple.

“The human hands have this amazing ability to touch something and tell if it’s soft or hard, if it’s wet, or even it’s temperature,” said Won, who is also director of the Control, Sensor, Network and Perception Laboratory in Temple’s College of Engineering. “We’re trying to emulate this tactile sensation with a device that will actually quantify this by giving us the mechanical properties of what we are feeling.”

Won said the tactile imaging sensor could aid doctors when they feel lesions, lumps or tumors while doing physical exams on patients by detecting the size and shape of the lesion or tumor, as well as its elasticity and mobility.

“Once a doctor feels a lesion, lump or tumor, they can use this device to actually characterize the mechanical properties of the irregularity that they have felt,” he said.

Won said that studies have shown that cancerous lesions and tumors tend to be larger, more irregular in shape or have harder elasticity. “Using the information gleaned by our device, we can determine the probability of this lesion or tumor being either malignant or benign.”

The portable tactile imaging sensor can be attached to any desktop or laptop computer that has a Firewire cable port. Equipped with four LED lights and a camera, the 4.5-inch device has a flexible transparent elastomer cube on the end, into which light is injected.

When the doctor feels an irregularity while giving a patient a physical exam, he or she can place the sensor against the skin where the irregularity was felt. The sensor uses the total internal reflection principle, which keeps the injected light within the elastomer cube unless an intrusion from a lesion or tumor changes the contour of the elastomer’s surface, in which case the light will reflect out of the cube.

The sensor’s camera will then capture the lesion or tumor images caused by the reflected light and they are processed with a novel algorithm developed by the CSNAP Lab to calculate the lesion’s mechanical properties.

Won stressed that the device is not designed to replace such tests as mammograms for breast tumors, but to assist the primary doctor in initially obtaining key information.

“Most primary physicians’ offices are not equipped to perform tests such as mammograms,” he said. “This device would provide the doctor key information by allowing them to quantify and display the lesion or tumor. With this information, they can decide whether to monitor it or send the patient to a specialist or hospital for a more definitive diagnosis.”

Won said that the device is non-invasive and can detect lumps or tumors up to 3 centimeters under the skin. “If you can feel it with your finger, you can see it with this device,” he said.

In addition to the advantages of being portable and non-invasive, the devise is also inexpensive. Won said the prototype cost approximately $500.