Integrative rehabilitation of residents chronic post-stroke in skilled nursing facilities: the design and evaluation of the BrightArm Duo.

PURPOSE: To describe the novel BrightArm Duo bimanual upper extremity (UE) rehabilitation system; to determine its technology acceptance and clinical benefit for older hemiplegic participants. METHODS: The system table tilted to adjust arm gravity loading. Participants wore arm supports that sensed grasp strength and wrist position on the table. Wrist weights further increased shoulder exertion. Games were designed to improve UE strength, motor function, cognition and emotive state and adapted automatically to each participant. The system underwent feasibility trials spanning 8 weeks in two skilled nursing facilities (SNFs). Participants were evaluated pre-therapy and post-therapy using standardized clinical measures. Computerized measures of supported arm reach, table tilt and number of arm repetitions were stored on a remote server. OUTCOMES: Seven participants had significant improvements in their active range of shoulder movement, supported arm reach, shoulder strength, grasp strength and their ability to focus. The group demonstrated higher arm function measured with FMA (p = 0.01) and CAHAI (p = 0.05), and had an improvement in depression (Becks Depression Inventory, II). BrightArm Duo technology was well accepted by participants with a rating of 4.4 out of 5 points. CONCLUSIONS: Given these findings, it will be beneficial to evaluate the BrightArm Duo application in SNF maintenance programs. Implications for Rehabilitation Integrative rehabilitation that addresses both physical and cognitive domains is promising for post-stroke maintenance in skilled nursing facilities. Simultaneous bilateral arm exercise may improve arm function in older hemiplegic patients several years after stroke. Virtual reality games that adapt to the patient can increase attention and working memory while decreasing depression in elderly.

Dual Stewart platform mobility simulator.

A robotic mobility simulator is being developed to allow training on various hapticly simulated surfaces while still being in the safe clinical environment. The simulator is integrated with a rich virtual environment displayed in front of the patient. The system uses two Stewart platform robots to render the walking surface geometry and condition. The hardware components of the platforms and the considerations behind their design are presented here. In addition, the nine state algorithm used for simulating the treadmill functioning is described along with the procedure used to transform the motion of the robots into walking in the virtual environment.

A virtual reality based exercise system for hand rehabilitation post-stroke: transfer to function.

We present preliminary results from a virtual reality (VR)-based system for hand rehabilitation that uses a CyberGlove and a Rutgers Master II-ND haptic glove. This system trains finger range of motion, finger flexion speed, independence of finger motion and finger strength. Eight chronic post-stroke subjects participated. In keeping with variability in both the lesion site and in initial upper extremity function, each subject showed improvement on a unique combination of movement parameters in VR training. These improvements transferred to gains on clinical tests, as well as to significant reductions in task completion times for the prehension of real objects. These results are indicative of the potential feasibility of this exercise system for rehabilitation in patients with hand dysfunction resulting from neurological impairment.

Virtual rehabilitation--benefits and challenges.

OBJECTIVES: To discuss the advantages and disadvantages of rehabilitation applications of virtual reality. METHODS: VR can be used as an enhancement to conventional therapy for patients with conditions ranging from musculoskeletal problems, to stroke-induced paralysis, to cognitive deficits. This approach is called "VR-augmented rehabilitation." Alternately, VR can replace conventional interventions altogether, in which case the rehabilitation is "VR-based." If the intervention is done at a distance, then it is called "telerehabilitation." Simulation exercises for post-stroke patients have been developed using a "teacher object" approach or a video game approach. Simulations for musculo-skeletal patients use virtual replicas of rehabilitation devices (such as rubber ball, power putty, peg board). Phobia-inducing virtual environments are prescribed for patients with cognitive deficits. RESULTS: VR-augmented rehabilitation has been shown effective for stroke patients in the chronic phase of the disease. VR-based rehabilitation has been improving patients with fear of flying, Vietnam syndrome, fear of heights, and chronic stroke patients. Telerehabilitation interventions using VR have improved musculo-skeletal and post-stroke patients, however less data is available at this time. CONCLUSIONS: Virtual reality presents significant advantages when applied to rehabilitation of patients with varied conditions. These advantages include patient motivation, adaptability and variability based on patient baseline, transparent data storage, online remote data access, economy of scale, reduced medical costs. Challenges in VR use for rehabilitation relate to lack of computer skills on the part of therapists, lack of support infrastructure, expensive equipment (initially), inadequate communication infrastructure (for telerehabilitation in rural areas), and patient safety concerns.

Virtual reality-based post-stroke hand rehabilitation.

A VR-based system using a CyberGlove and a Rutgers Master II-ND haptic glove was used to rehabilitate four post-stroke patients in the chronic phase. Each patient had to perform a variety of VR exercises to reduce impairments in their finger range of motion, speed, fractionation and strength. Patients exercised for about two hours per day, five days a week for three weeks. Results showed that three of the patients had gains in thumb range (50-140%) and finger speed (10-15%) over the three weeks trial. All four patients had significant improvement in finger fractionation (40-118%). Gains in finger strength were modest, due in part to an unexpected hardware malfunction. Two of the patients were measured against one-month post intervention and showed good retention. Evaluation using the Jebsen Test of Hand Function showed a reduction of 23-28% in time completion for two of the patients (the ones with the higher degrees of impairment). A prehension task was performed 9-40% faster for three of the patients after the intervention illustrating transfer of their improvement to a functional task.

Virtual reality-enhanced stroke rehabilitation.

A personal computer (PC)-based desktop virtual reality (VR) system was developed for rehabilitating hand function in stroke patients. The system uses two input devices, a CyberGlove and a Rutgers Master II-ND (RMII) force feedback glove, allowing user interaction with a virtual environment. This consists of four rehabilitation routines, each designed to exercise one specific parameter of hand movement: range, speed, fractionation or strength. The use of performance-based target levels is designed to increase patient motivation and individualize exercise difficulty to a patient's current state. Pilot clinical trials have been performed using the above system combined with noncomputer tasks, such as pegboard insertion or tracing of two-dimensional (2-D) patterns. Three chronic stroke patients used this rehabilitation protocol daily for two weeks. Objective measurements showed that each patient showed improvement on most of the hand parameters over the course of the training. Subjective evaluation by the patients was also positive. This technical report focuses on this newly developed technology for VR rehabilitation.

Virtual reality-based orthopedic telerehabilitation.

Rehabilitation interventions in remote areas are problematic because of distance and available resources. Orthopedic impairments acquired by individuals in remote areas can then lead to permanent disabilities/loss of function because of lack of appropriate rehabilitation. A system being developed by Rutgers and Stanford Universities provides therapy at the patient's home, with remote monitoring and periodic re-assessment. This telerehabilitation system uses virtual reality and haptic interfaces, and a pair of networked PCs. It is intended for rehabilitation of patients with hand, elbow, knee and ankle impairments. Data from the first patient treated with the telerehabilitation system is encouraging.

Orthopedic rehabilitation using the "Rutgers ankle" interface.

A novel ankle rehabilitation device is being developed for home use, allowing remote monitoring by therapists. The system will allow patients to perform a variety of exercises while interacting with a virtual environment (VE). These game-like VEs created with WorldToolKit run on a host PC that controls the movement and output forces of the device via an RS232 connection. Patients will develop strength, flexibility, coordination, and balance as they interact with the VEs. The device will also perform diagnostic functions, measuring the ankle's range of motion, force exertion capabilities and coordination. The host PC transparently records patient progress for remote evaluation by therapists via our existing telerehabilitation system. The "Rutgers Ankle" Orthopedic Rehabilitation Interface uses double-acting pneumatic cylinders, linear potentiometers, and a 6 degree-of-freedom (DOF) force sensor. The controller contains a Pentium single-board computer and pneumatic control valves. Based on the Stewart platform, the device can move and supply forces and torques in 6 DOFs. A proof-of-concept trial conducted at the University of Medicine and Dentistry of New Jersey (UMDNJ) provided therapist and patient feedback. The system measured the range of motion and maximum force output of a group of four patients (male and female). Future medical trials are required to establish clinical efficacy in rehabilitation.

A virtual-reality-based telerehabilitation system with force feedback.

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.

PC-based telerehabilitation system with force feedback.

A PC-based orthopedic rehabilitation system was developed for use at home, while allowing for remote monitoring from the clinic. The home rehabilitation station has a Pentium II PC with graphics accelerator, Polhemus tracker, and a novel Multipurpose Haptic Control Interface with its own Pentium board. This interface is used to sample 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 two physical therapy exercises (DigiKey and Ball) and two functional rehabilitation exercises (Peg Board test and Ball game). All VR 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 running Oracle server is used to maintain the patient database, monitor progress and change exercise level of difficulty. This allows for timely patient progress monitoring and repeat evaluations over time from the Clinic. The system will soon start clinical trails at Stanford Medical School, with progress being monitored remotely from Rutgers University. Other rehabilitation haptic interfaces under development include devices for elbow, and knee rehabilitation connected to the Multipurpose Haptic Control Interface.

Virtual reality-based training for the diagnosis of prostate cancer.

Prostate malignancies are the second leading cause of cancer deaths among men. The most common method of detecting this disease is digital rectal examination (DRE). Current DRE training is inadequate, since the number of patients that students can practice on is limited. Furthermore, allied care personnel do not train in screening for prostate cancer. Finally, there is no objective way to follow the improvement in DRE skills for medical personnel. This paper presents a virtual reality-based simulator that addresses the above problems. The prototype consists of a PHANToM haptic interface which provides feedback to the trainee's index finger, a motion restricting board, and an SGI workstation, which renders the patient's anatomy. Four types of prostates were modeled--normal, enlarged with no tumor, incipient malignancy (single tumor), and advanced malignancy (tumor cluster). Human factors studies were conducted on both nonmedical students and urology residents in order to quantify the system usefulness. After only five minutes of training, nonmedical students had a 67% correct diagnosis rate of malignant versus nonmalignant cases. This compared with 56% for urology residents in the same trials. Subjective evaluation by the residents pointed out the need to improve the virtual prostate model realism. A control group formed of urology residents performed the same trials on a modified Merck Procar simulator. The control group scored significantly better (96% correct diagnosis of malignancies). We conclude that the virtual prostate palpation simulator, while promising, needs significant improvement in both model realism and haptic interface hardware.

Evaluation of robot-based registration for subtraction radiography.

Digital subtraction of (plane film) radiographs of an area of interest taken over time is a powerful diagnostic tool. In dentistry for example, this is used to detect and treat periodontal disease (i.e. the sequence of diseases that leads to the loss of bone supporting the teeth). A precondition of subtraction radiography is correct three-dimensional registration of the film and X-ray source, without which the subtraction images are meaningless. A small misalignment can be compensated for by post-processing of the digitized films (by correspondence and rectification) to remove artifacts due to positioning errors. This paper presents a novel approach to subtraction radiography which replaces customary mechanical alignment methods (such as a stent or cephalostat) with a robot. A mechanical stent is a short rod attached at one end to the X-ray source and at the other to a mechanical appliance protruding from the patient's mouth. An experimental system was constructed which creates a 'sensorized stent' by integrating a plastic mouth appliance (with the impression of the patient's teeth), a robot carrying an X-ray source and a host computer. Results showed that the robotic system was superior to the mechanical alignment approach, due to its excellent accuracy and repeatability. This resulted in much less variation in the non-registered X-ray images, and in a smaller standard deviation in the intensities of subtracted images overall. The results suggest that in the future, diagnostic studies including subtraction radiography will not need either mechanical alignment (which is imprecise) or post-processing registration (which is time consuming).

Computerized hand diagnostic/rehabilitation system using a force feedback glove.

This paper describes recent results of a unified computerized system for hand diagnosis and rehabilitation. Automatic diagnosis data collection and Virtual Reality rehabilitation exercises are the main characteristics of the system. The diagnosis subsystem includes a tactile sensing glove in addition to standard devices such as electronic dynamometer, pinchmeter and goniometer. Three standard rehabilitation exercises were simulated in a Virtual Reality environment, using the WorldToolKit graphics library. The first two exercises (ball squeezing and DigiKey) allow measurement of finger forces exerted during the rehabilitation routine. The third exercise (Peg board) involves the patient's visual-motor coordination. The rehabilitation subsystem uses a VPL DataGlove retrofitted with Rutgers Master (RM-I) and its interface. The exercises involve manipulation of objects with different stiffnesses and geometry. Grasping forces were modeled and fed back using the Rutgers Master worn on patient's hand. Data is gathered in real time from both diagnosis and rehabilitation subsystems. Finger specific forces recorded during rehabilitation exercises allow better diagnosis of the patient impairment. An ORACLE database is used to store and manipulate patients' records. Proof of concept trials were performed in a clinical environment. Some results of patient records analysis are presented in this paper. A new version of the system using an RM II haptic interface is presently under consideration.

Dynamic force feedback in a virtual knee palpation.

A virtual model of a knee joint with muscles, ligaments and bones has been developed. This model includes realistic 3-D surface deformation and tissue stiffnesses. Tissue and bone deformation (palpation) produces real time force feedback to the user hand wearing a DataGlove and Rutgers Master. Collision detection algorithms determine when and where the virtual hand palpates the surface model. This user interaction with the muscles and bones of a human knee model may be used as a training and planning tool for knee surgery.

Real-time sensing of tooth position for dental digital subtraction radiography.

Dental digital subtraction radiography requires accurate repositioning of the patient and X-ray source in order to facilitate correct diagnostic of bone loss. Present mechanical repositioning systems do not allow radiography of posterior teeth, and are uncomfortable for the patient. A new repositioning system that utilizes a six degrees of freedom position sensor and a robot arm with X-ray source is proposed. A mathematical model for the system is given, and the robot arm solution is obtained based on patient position. An error analysis is performed in order to determine the influence of sensor and robot errors on system accuracy. A series of experiments to determine sensor noise and accuracy are described. These tests showed relatively small errors over the work envelope of the sensor. Further tests showed that there is no adverse effect due to the presence of metal work in the patient's mouth. The high bandwidth of the sensor may allow real time tracking of small movements of the patient's head.