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Telerehabilitation system using haptic interfaces and virtual reality techniques (TELEDOC)

Deliverables

This project intends the development of a complete system for telerehabilitation making also use of VR techniques. The use of VR applications provides the capability to create an environment in where the intensity of feedback and training can be systematically manipulated and enhanced in order to create the most appropriate, individualized motor learning paradigm. In addition VR-based rehabilitation systems have several other advantages. Similar to computer games, VR rehabilitation exercises can be made to be engaging which is important in terms of patient motivation. VR sensor technology can also be used to fully quantify any progress made by the patient, especially in terms of motor control improvement. The VR-based telerehabilitation application supports online interaction between therapist and a VR-enabled patient site. The shared VR-based telerehabilitation system is a software platform for real-time patient-therapist interactions. Its two sites are each equipped with a PC, a video camera and the corresponding haptic interface. Data transmitted between the two sites include audio, video, forces, images, graphs and control commands. Additionally, the forces displayed to the patient's hand are sent over the network to the clinic site. The VR application contains graphic elements (push buttons) which allow either the therapist or the patient to open a video consultation channel. TELEDOC project has developed up to 10 different videogames. Although they are all indicated to be integrated in this rehabilitation device, the testers of the system chose only 3 of them as really useful: - PING-PONG Game objective: To hit the ball as many times as possible. Control: The player/patient moves vertically the red or the blue piece in order to hit the ball. Characteristics: The speed of the ball increases as the game goes on. The ball bounce depends on the incidence angle. - LABYRINTH Game objective: To take the ball to the end of the board and avoid falling in the holes. Control:The player/patient controls the labyrinth inclination making the ball rolling in the desired direction. Characteristics: The ball bounces off the walls and has inertia. - FISHERMAN Game objective: To fish 25 fish as fast as possible. Control: The player/patient can take up and down the fish hook. Characteristics: When the player picks up a fish, he has to put it inside the little boat. Blue fish are worth 3 points, green ones are worth 2 points and orange ones are worth 1 point. Fish have different speed and little vertical movement. A short introductory video should be included to explain how to use the system. As TELEDOC is addressed to the general public, it cannot be taken for granted the fact that users have any previous knowledge in computer science. Furthermore, target population sector of this project are rural areas distant from main cities. Under these circumstances only very simple videogames are effective. Ping-Pong is the simplest and easiest videogame. It is the only one that can be used by the vast majority of public. The other two videogames (Fisherman and Labyrinth) are also very simple, but some users need quite a lot of time to understand the rules of the game. From the side of the specialist, the setting of the operational parameters of the Ping-Pong videogame is extremely easy. On a general basis, TELEDOC users will use the system for the first time, so it would be advisable to include a screen displaying a short introductory video giving instructions on how to grip the joystick and how to play the videogame. The socio-economical assessment has been made by the consortium members and by more than 35 rehabilitation specialists who attended the IX Jornadas sobre Avances en Medicina Física y Rehabilitación (IX Congress on Advances in Physical Medicine and Rehabilitation) , held from the 13th to the 17th of February 2005 in Sallent de Gallego (Spain). A multimedia video containing TELEDOC characteristics, use and demonstration was played in the above- mentioned congress. After watching the video, the rehabilitation specialists answered a survey and gave their opinions on TELEDOC technology. From the technical point of view, the specialists expressed their favourable opinions. From the socio-economical point of view, they pointed out the following items regarding the VR application: -The developed system can be used in a wide range of applications. -The use of this technology will increase the number of patients each specialist can supervise. The quality of the rehabilitation treatment will be better. -The system should be as simple as possible, so both patients and specialists can make use of it. Industrial partners in the consortium have expressed their satisfaction with the obtained results.
The system developed in TELEDOC project consists of a pair of PC's one at the patient's site (home or satellite assistance centre) and the other at the specialist site (clinic or central assistance centre), connected over the Internet or local network. The home rehabilitation station in turn consists of a haptic interface, a multipurpose control interface connected to the PC, a net camera, and a microphone array. The different subsystems are briefly described in the following paragraphs: 1) The haptic device. It is specific for the rehabilitation of the upper limb (wrist, elbow, shoulder) and can operate in two modes: - active mode, for mobilisation of patient's articulation in case of patients with serious impairment. - passive mode, where the patient performs exercises moving the device. Maximum force, excursion ranges, number of repetitions, safety aspects, are set by the therapy expert. 2) The VR-based tele-rehabilitation application. The haptic interface is equipped with a screen in which the patient can watch the video games he is playing with. It is a 15- standard flat screen. The images are generated by a PC also integrated in the haptic interface. In the project, more than 14 video games have been created whose performance (range and speed of movements) can be adjusted by the specialist according to every patient's needs. To play the videogames, instead of a conventional joystick, the two handles in the haptic interface are used: the X-Y table handle and the spherical system handle. 3) The multipurpose control interface is self-configurable software detecting which device is connected to it at any given time. This eliminates the need for reprogramming every time a rehabilitation device is plugged in. 4) A database. A PC is used as a server that reads patient's exercise data, stores it in a database, and analyses the patient's progress. Communication between the home and clinic stations will be done over the Internet, while lower bandwidth telephone lines could also be used.