Improved interaction methods for medical visualization with floating images

Earlier we have reported on developing new medical visualization technology with floating images using the new optical device 'DCRA'. Experience with prototype systems has demonstrated the feasibility of easy visualization of complex spatially distributed data, such as MRI or CT data sets; but also indicated the need for better interaction methods. Here we introduce new developments in interaction with floating image visualization systems. A new method improves the sensing of hand position and gestures for the flexible manipulation of the floating images without holding any devices. Another method uses a simple but robust method to sense directly the users' finger when touching the floating image, to give a natural interactive experience. Still another new method uses the 'Phantom' haptic device to give the user a tactile feedback on the position of the floating image in the air, as a help for the accurate positioning of markers. We describe the structure and operation of our interactive methods, and discuss the possibilities of their practical application.