[show abstract][hide abstract] ABSTRACT: Many applications use electrostimulation of the human skin to provide tactile sensation. The effect of electrotactile stimulations were studied on a 6x6 matrix of tactile electrodes placed on the anterior part of the tongue. The liminary threshold with continuous or discontinuous waveform and patterns with 2 or 4 electrodes was investigated. The result suggest that for energy saving and to improve the yield, it would probably be better to use discontinuous stimulation with two electrode patterns.
[show abstract][hide abstract] ABSTRACT: Under conventional "open-" surgery, the physician has to take care of the patient, interact with other clinicians and check several monitoring devices. Nowadays, the computer assisted surgery proposes to integrate 3-D cameras in the operating theatre in order to assist the surgeon in performing minimally invasive surgical punctures. The cameras localize the needle and the computer guides the surgeon towards an intracorporeal clinically defined target. A visualization system (screen) is employed to provide the surgeon with indirect visual spatial information about the intracorporeal positions of the needle. The present work proposes to use another sensory modality to guide the surgeon, thus keeping the visual modality fully dedicated to the surgical gesture. For this, the sensory substitution paradigm using the Bach-y-Rita's "Tongue Display Unit" (TDU) is exploited to provide to the surgeon information of the position tool. The TDU device is composed of a 6 x 6 matrix of electrodes transmitting electrotactile information on the tongue surface. The underlying idea consists in transmitting information about the deviation of the needle movement with regard to a preplanned "optimal" trajectory. We present an experiment assessing the guidance effectiveness of an intracorporeal puncture under TDU guidance with respect to the performance evidenced under a usual visual guidance system.
[show abstract][hide abstract] ABSTRACT: Performing minimal-invasive surgical punctures require guiding a needle toward an intracorporeal clinically-defined target. As this technique does not involve cutting the body open, a visualization system is employed to provide the surgeon with indirect visual spatial information about the intracorporeal positions of the tool. One may consider that such systems reduce the ergonomics of the situation as they generate a decorrelation between the actual movement of the needle and the displayed information about this movement. The present study aims at assessing the guidance of an intracorporeal puncture under a lingual electrotactile sensory substitution device - the Tongue Display Unit (TDU) - with respect to the performance evidenced under a computer-rendered visualization system. The TDU device provides information about the deviation of the needle movement with regard to a pre-planned "optimal" trajectory. Experimental results show that - (1) the stimulations furnished by the TDU are efficient enough to guide accurately one's puncture, - and (2) that previous training using the visualization system does not improve performances obtained under subsequent TDU guidance. Finally, results are discussed in terms of efficiency and usability of the TDU in the context of guiding minimally-invasive surgical gesture.
[show abstract][hide abstract] ABSTRACT: Pressure ulcers are recognized as a major health issue in individuals with spinal cord injuries and new approaches to prevent this pathology are necessary. An innovative health strategy is being developed through the use of computer and sensory substitution via the tongue in order to compensate for the sensory loss in the buttock area for individuals with paraplegia. This sensory compensation will enable individuals with spinal cord injuries to be aware of a localized excess of pressure at the skin/seat interface and, consequently, will enable them to prevent the formation of pressure ulcers by relieving the cutaneous area of suffering. This work reports an initial evaluation of this approach and the feasibility of creating an adapted behavior, with a change in pressure as a response to electro-stimulated information on the tongue. Obtained during a clinical study in 10 healthy seated subjects, the first results are encouraging, with 92% success in 100 performed tests. These results, which have to be completed and validated in the paraplegic population, may lead to a new approach to education in health to prevent the formation of pressure ulcers within this population. Keywords: Spinal Cord Injuries, Pressure Ulcer, Sensory Substitution, Health Education, Biomedical Informatics.