Development of a sterile Interaction Device during Image guided minimal-invasive Interventions

For correct setting and control of imaging during image-guided Magnetic Resonance (MR) procedures (e.g. changing the slice orientation), the radiologist currently depends heavily on the assistants in the control room. The communication between the surgeon and the assistant is difficult due to acoustic noise generated by the MR gradients. The development for a dedicated interventional interaction device is addressed in this work, which includes the development and evaluation of a sterile, MR-compatible capacitive gesture controller. The gesture controller consists of a surgical drape with four capacitive sensors, that are made of conductive fabric. These sensors are based on the principle of electrical capacitance between isolated conductive structures. Measurements of these capacitances are exploited to calculate the distance of a hand to one of the sensors. By comparing the distances of the hand to each sensor, simple swipe gestures can be detected. The sensor unit is connected to a micro-controller, which allows direct and fast processing of the incoming data. To evaluate the prototype, a user study with 25 participants took place. Each user had to perform the four swiping gestures and the hold gesture in a specific order. The gesture controller is capable of registering five different gestures (left-right, right-left, up-down, down-up, hold). A survey of the second prototype showed, that in 92,4% of cases, the correct gesture was registered. Clinical relevance This interaction device allows the practicing physician to manipulate the imaging independently and in a sterile manner, thus enabling a significant improvement in work-flow.