Manipulation Practice for Upper-Limb Amputees Using Virtual Reality

Abstract

We developed a novel interface that gives upper-limb amputees a virtual hand that can manipulate objects in a challenging environment. The interface registers specific myokinetic activity of the residual limbs, and encodes the intended voluntary movements that are then actualized as virtual hand motions. The composite myokinetic interface-virtual reality (MKI-VR) system consists of an array of pressure sensors mounted in an arm sleeve, sensors of elbow-and shoulder-joint angles, a trained filter derived from the pseudoinverse of a response matrix, and a virtual hand model, programmed in Java 3D. Users can manipulate virtual objects such as balls and pegs in a 3D training environment, while their performance at various difficulty levels is scored. In preliminary tests, upper-limb amputees readily gained the ability to grasp and release virtual objects. We propose the utility of the MKI-VR system both as an assessment tool for rehabilitation engineers, and as a motivator for amputees to exercise and thereby maintain their residual motor ability.

Pressure signature of forearm as predictor of grip force

“…Although we report on only nondisabled subjects, the results may apply to the transradial amputee population, since previous studies have shown that the amplitude of single-finger volitions can by extracted via FMG [15,17]. Test conditions were limited to the arm and wrist in a fixed neutral position in the horizontal plane.…”

“…The ability of FMG to resolve hand postures and individual finger motions has previously been demonstrated in transradial amputees, some of whom were >15 years postamputation and had relatively poor residua [14][15]17]. More recently, it has been shown that six different grip types can be classified with considerable accuracy when FMG is used to measure intact forearms [21].…”

“…Volitions concerning the hand, such as individual finger flexions, are encoded in the forearm FMG as characteristic force images that can be readily decoded for multifinger biomimetic control of robotic and virtual hands by amputees [1,[13][14][15][16]. To date, FMG is the only neuromuscular imaging modality that has demonstrated simultaneous multifunctional and multiple degrees-of-freedom control of prosthetic hands [13][14][15]17], including multifinger operation by amputees. Previous results with amputees suggested the potential of FMG as a register of force magnitude volition [13].…”

Towards the implementation of natural prosthetic elbow motion using upper limb joint coordination

“…Arm amputation level has a strong influence on the affected person's ability to perform ADLs, and compared to lower amputation levels, the compensatory strategies developed by transhumeral amputees to overcome the impairment involve significantly more the rest of the body, causing shoulder, back, and contralateral limb disorders [4]. Numerous studies have investigated alternatives to bi-electrodes myoelectric control, such as solutions based on ultrasound signal [5], myokinemetric signal [6], myokinetic signal [7], mechanomyographic signal [8], and residual limb motion [9], [10]. One possible and yet less explored solution relies on the use of residual limb motion and the knowledge of human upper limb motor control to design a more natural control strategy.…”

Development of on-bed lower extremity exercise system for use with networked virtual space

“…Manfuladevi et.al. developed another VR training system to train artificial hand control for amputee [2].…”