Abstract-The Rutgers Master II-ND glove is a haptic interface designed for dextrous interactions with virtual environments. The glove provides force feedback up to 16 N each to the thumb, index, middle, and ring fingertips. It uses custom pneumatic actuators arranged in a direct-drive configuration in the palm. Unlike commercial haptic gloves, the direct-drive actuators make unnecessary cables and pulleys, resulting in a more compact and lighter structure. The force-feedback structure also serves as position measuring exoskeleton, by integrating noncontact Hall-effect and infrared sensors. The glove is connected to a haptic-control interface that reads its sensors and servos its actuators. The interface has pneumatic servovalves, signal conditioning electronics, A/D/A boards, power supply and an imbedded Pentium PC. This distributed computing assures much faster control bandwidth than would otherwise be possible. Communication with the host PC is done over an RS232 line. Comparative data with the CyberGrasp commercial haptic glove is presented.

A PC-based orthopedic rehabilitation system was developed for use at home, while allowing remote monitoring from the clinic. The home rehabilitation station has a Pentium II PC with graphics accelerator, a Polhemus tracker, and a multipurpose haptic control interface. This novel interface is used to sample a patient's hand positions and to provide resistive forces using the Rutgers Master II (RMII) glove. A library of virtual rehabilitation routines was developed using WorldToolKit software. At the present time, it consists of three physical therapy exercises (DigiKey, ball, and power putty) and two functional rehabilitation exercises (peg board and ball game). These virtual reality exercises allow automatic and transparent patient data collection into an Oracle database. A remote Pentium II PC is connected with the home-based PC over the Internet and an additional video conferencing connection. The remote computer is running an Oracle server to maintain the patient database, monitor progress, and change the exercise level of difficulty. This allows for patient progress monitoring and repeat evaluations over time. The telerehabilitation system is in clinical trails at Stanford Medical School (CA), with progress being monitored from Rutgers University (NJ). Other haptic interfaces currently under development include devices for elbow and knee rehabilitation connected to the same system.

Stroke is one of the leading causes of death and disability worldwide. Its prevalence calls for innovative rehabilitation methods. The Rutgers Arm is a novel upper extremity rehabilitation system consisting of a low-friction table, three-dimensional (3D) tracker, custom forearm support, PC workstation, library of Java 3D virtual reality (VR) exercises, clinical database module, and a tele-rehabilitation extension. The system was tested on a chronic stroke subject, under local and tele-rehabilitation conditions, over 5 weeks of training. Results show improvements in arm motor control and shoulder range of motion, corresponding to improved Fugl-Meyer test scores. Exercise duration, level of difficulty, and patient motivation were maintained under tele-rehabilitaion. A 1-week retention trial showed that gains were maintained.

The paper presents the simulation and modeling of gait on a system using two prototype compact Stewart platforms. Control issues raised by the reduced size of the robots and hence their lower power output are discussed. The flexible haptic material concept is introduced and used to realistically model heterogeneous haptic surfaces simulating the virtual ground. An algorithm for virtual foot/virtual surface contact modeling and transforming the platform motion into walking in VEs is also presented.