Tactile Sensing and Tactile Imaging in Detection of Cancer

Since Hippocrates, the human sense of touch has been the most prevalent and successful medical diagnostic technique. A great variety of diseases were diagnosed through tactile sensing including detection of malignant tumors. Hippocrates in 400 B.C. wrote as follows: “... Such swellings as are soft, free from pain, and yield to the finger, ... and are less dangerous than the others. ... then, as are painful, hard, and large, indicate danger of speedy death; but such as are soft, free of pain, and yield when pressed with the finger, are more chronic than these...” [28]. In ancient medicine, medical practitioners have used diagnostic methods based on assessment of mechanical properties of tissues for diagnosing and treating ailments without much help from other tests. During the last century, traditional physical examination techniques were becoming outmoded and were often considered of little clinical value in comparison with many other modern diagnostic technologies. Palpation is only briefly addressed in medical school, and few physicians have the tactile ability to detect subtle variations of tissue elasticity. Few physicians are willing to devote the necessary time to master the technique, despite the fact that the American Cancer Society guidelines suggest for women that clinical breast examination (CBE) be part of a periodic health examination [1] and the American Urological Association in their 2009 Best Practices Statement recommended that men who wish to be screened for prostate cancer should have both a prostate-specific antigen (PSA) test and a digital rectal examination (DRE) [2]. The development of modern diagnostic technologies has brought a decline in physical examination skills. But is this technique on the way to extinction? During the last two decades, several devices AQ1 CoNtENtS