Tactile optical sensor for use in minimal invasive surgery.

In minimal invasive surgery high sensory palpation of the organs is largely lost. It is the purpose of this work to recover tactile sensing for the surgeon. To achieve this goal, a new tactile optical pressure sensor has been developed which allows to display 64 measuring points on a 0.64 cm2 surface area with a digital resolution of 12 bits. The sensor has been conceived for application in laparoscopic grasping forceps and can also be integrated into a sensing rod, both 15 mm in outside diameter. This optical sensor allows us to display graphically indurations spread in the tissue. Furthermore, the measured values serve to activate a vibrotactile display unit for tactile feedback onto the surgeon's fingertip. In order to obtain further information about the requirements for an analog tactile display, an actuatorarray with 144 pins on a 4 cm2 surface area was built. The array allows various test objects to be recognized in a true scale presentation by exploratory movements of the fingers.