Incorporating Haptic Effects Into Three-Dimensional Virtual Environments to Train the Hemiparetic Upper Extremity

 In the 12 years since this came out and and the 37 posts written in the last 10 years has your hospital done one damn thing with haptics?

• haptics (37 posts to May 2011)

  Do you prefer your hospital incompetence NOT KNOWING? OR NOT DOING?

   

Incorporating Haptic Effects Into Three-Dimensional Virtual Environments to Train the Hemiparetic Upper Extremity

2009, Ieee Transactions on Neural Systems and Rehabilitation Engineering a Publication of the Ieee Engineering in Medicine and Biology Society

  
Exoskeleton Robots provide an alternative to end effector robots in their ability to controlindividual joint torques and velocities. The ARMin system facilitates a patient interacting invirtual environments utilizing a principle described as minimal intervention [10]. The robot provides assistance only when the subject moves outside predetermined trajectories or range of joint torques. The PneuWREX is a four DOF, pneumatically actuated exoskeleton with a grip sensor that allows subjects to train the hand and arm as a functional unit in a series of complex virtual environments [11]. The RUPERT system [12] is a portable, wearable,exoskeleton robot that facilitates movement of the arm and shoulder and can facilitate interactions with real world objects.Van der Linde et al describes the Haptic Master an admittance controlled haptic robot that senses forces applied by the subject and controls motion of the subjects arms in response the applied forces. It is well suited for virtual environment interface and neurorehabilitation [13],[14]. Several robotic rehabilitation systems have been designed using the Haptic Master.Harwin et al. designed the GENTLE/S a system in which participants perform upper extremity movements using the Haptic Master, in a series of virtual environments that follow a continuum of visual complexity [15]. The robot augments the participant's movement with a haptic spring and damper system that maintains a trajectory and velocity determined by the participant's therapist. The spring and damper system control is modeled using the “bead” concept [16].The Am Coordination Training 3D Device utilizes the Haptic Master to study the kinematics of three dimensional reaching activities by persons with upper extremity hemiparesis in virtualspace [17]. The ADLER system which utilizes the Haptic Master, to facilitate real world two and three dimensional reaching and pointing activities, can also be combined with a ring gimbal, produced by Moog, [14] to add an additional 3 passive degrees of freedom to facilitate performance and measure the kinematics of more complex real world activities of daily living[18]. In a pilot study, our group utilized the Haptic Master incorporating a gimbal to facilitate training the hand and arm as a functional unit in virtual environments [19].The systems described above utilize a variety of models and technology to facilitate and augment upper extremity movement for persons with hemiparesis. One common aspect to the majority of these systems is that trajectories, velocities, and assistance levels are predetermined and maintained throughout the movement. The approach described in this paper differs in that it utilizes the Haptic Master's ability to measure forces, velocity and position in real time,allowing it to utilize on-line algorithms to adjust haptic effects such as assistance against gravity, assistance in the direction of the target, and damping. These adjustments can be applied during the movement to enable the subject to accomplish the motor task with minimal external support. In addition, the level of assistance can be varied from trial to trial depending on the subject's performance throughout a session, maximizing the participant's output while maintaining a reasonable success rate. Finally, the Haptic Master as a newer generation, admittance controlled robot combines the ability to render minimal friction with the capacity to create very rigid constraints that can be used to present haptic objects in virtual environments for the indirect shaping of arm movement trajectories.Another line of inquiry has suggested that symmetrical movements of the upper extremities may activate similar neural networks in both hemispheres and may facilitate inherent interlimb coordination resulting in improved functional therapeutic outcomes for persons with hemiplegia [20]. It is postulated that during symmetrical bilateral movements, both hemispheres are activated and abnormal interhemispheric cortical inhibition is balanced [21].Several authors cite improvements in hemiparetic upper extremity motor performance as a result of bilateral upper extremity training [22], [23], [24].This paper describes the design process and rehabilitation applications of three simulations for the Haptic Master. Using rich virtual environments, key features utilized in these simulations include, haptic effects, custom visual presentations, 3D scalable workspaces, direct motion analysis, and adaptive algorithms that modify task difficulty based on a user's success rate.One of these simulations facilitates bilateral, symmetrical movement of the two upper extremities and the other two are for unilateral training.