A medical physical examination of a patient is first and foremost performed through touch, yet doctors can only learn a limited amount of information from what they feel. Temple University researchers have now developed a prototype device that will not only emulate human tactile sensation, but also quantify it.
Chang-Hee Won, an associate professor of electrical and computer engineering at Temple, who developed the tactile imaging sensor explained:
“The human hands have this amazing ability to touch something and tell if it’s soft or hard, if it’s wet, or even its temperature. 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.”
The tactile imaging sensor could assist doctors during patients’ physical examinations when feeling for lesions, lumps or tumors by identifying the size and shape of the lesion or tumor, as well as its elasticity and mobility.
Won, who is also director of the Control, Sensor, Network and Perception Laboratory in Temple’s College of Engineering said:
“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 states that studies have demonstrated that cancerous lesions and tumors are likely to be larger, more irregular in shape or have harder elasticity, saying:
“Using the information gleaned by our device, we can determine the probability of this lesion or tumor being either malignant or benign.”
Any desktop or laptop computer with a Fire wire cable port can support the portable tactile imaging sensor, which is equipped with four LED lights and a camera. On the end of the 4.5-inch device is a flexible transparent elastomer cube into which light is injected. The sensor can then be placed against the patient’s skin on the area where the doctor felt an irregularity during a physical examination.
The device uses the total internal reflection principle, which contains the injected light within the elastomer cube apart from when an intrusion from a lesion or tumor changes the contour of the elastomer’s surface. In this case the light will reflect out of the cube.
The sensor’s camera subsequently captures the lesion or tumor images caused by the reflected light, which are processed with a novel algorithm developed by the CSNAP Lab for calculating the lesion’s mechanical properties.
Won warns that the device is not designed to replace tests like a mammography to detect breast tumors, but to help primary doctors in initially getting key information. He states:
“Most primary physicians’ offices are not equipped to perform tests such as mammograms. 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.”
According to Won the device is non-invasive and is able to identify lumps or tumors up to 3 centimeters under the skin. He said:
“If you can feel it with your finger, you can see it with this device.”
The advantage of the tactile imaging sensor is not only that it is portable and non-invasive; it is also inexpensive with the prototype costing around $500.
Written by Petra Rattue