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Implant provision of key, pinch and power grips in a C6 tetraplegic

  • T. A. Perkins
  • G. S. Brindley
  • N. de N. Donaldson
  • C. E. Polkey
  • D. N. Rushton
Biomedical Engineering

Abstract

An 11-channel multiplexed stimulator of nerves and muscles in the left forearm was implanted for hand control in January 1986 in a 21 year old woman who, after sustaining a C6 spinal lesion 7 years earlier, had voluntary shoulder and elbow movement but paralysed hands, trunk and legs. The patient controls the stimulation via a microcomputer control box and an RF transdermal link. We have investigated the control of her stimulated hand with a joystick under her contralateral hand which she moves from the shoulder and elbow. Since 1986, we have tried a variety of joystick control schemes involving power and key grips. Currently, for grip adjustment, forward and backward joystick movements correspond to thumb extension and abduction, respectively giving in addition both finger and wrist extension, whereas right and left joystick movements yield first closure and thumb opposition/adduction and flexion, respectively. Useful grasps are available by moving the joystick forward and then left (key grip), by moving the joystick backward and left (pinch grip), or by moving the joystick back and right (power grip). Thus, three distinct grips may be selected using these three quadrants of joystick movement. An additional control mode was found to be desirable to augment the patient's limited voluntary wrist positioning and provide wrist stability while adjusting finger grip.

Keywords

FES finite state control grip selection hand function restoration implant joystick portable microcomputer tetraplegia 

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References

  1. Andrews, B. J., Barnett, R. W., Phillips, G. F., Kirkwood, C. A., Donaldson, N. de N., Rushton, D. N., andPerkins, T. A. (1989): ‘Rule-based control of a hybrid FES orthosis for assisting paraplegic locomotion,’Automedica,11, pp. 175–199Google Scholar
  2. Brindley, G. S., Donaldson, N. de N., Perkins, T. A., Polkey, C. E., andRushton, D. N. (1989): ‘Two-stage keygrip movement by joystick from an 11-channel upper limb FES implant in C6 tetraplegia.’ Proc. Biological Engineering Society Conf. on Electrical Stimulation of Muscle, Hexham, UK, January 1989, 41Google Scholar
  3. Donaldson, N. de N., andDonaldson, P. E. K. (1986): ‘When are actively balanced biphasic (‘Lilly’) stimulating pulses necessary in a neurological prosthesis? II pH changes; noxious products; electrode corrosion; discussion,’Med. Biol. Eng. Comput.,24, pp. 50–56MathSciNetCrossRefGoogle Scholar
  4. Donaldson, N. de N. (1986): ‘A 24-output implantable stimulator for FES.’ Proc. 2nd Vienna Int. Workshop on Functional Electrical Stimulation, Department of Biomedical Engineering, University of Vienna, Austria, pp. 197–200Google Scholar
  5. Donaldson, P. E. K. (1983): ‘The Cooper cable: an implantable multiconductor cable for neurological prostheses,’Med. Biol. Eng. Comput.,21, pp. 371–4CrossRefGoogle Scholar
  6. Donaldson, N. de N. (1990): ‘A new multiplexed stimulator for FNS’in Popovic, D. B. (Ed.): ‘Advances in the external control of human extremities, X’ (Nauka, Belgrade) pp. 345–358Google Scholar
  7. Johnson, M. W., andPeckham, P. H. (1990): ‘Evaluation of shoulder movement as a command control source,’IEEE Trans. BME-37, pp. 876–885Google Scholar
  8. Keith, M. W., Peckham, P. H., Thrope, G. B., Buckett, J. R., Stroh, K. C. andMenger, V. (1988): ‘Functional neuromuscular stimulation neuroprostheses for the tetraplegic hand,’Clin. Orthop. Rel. Res.,233, pp. 25–33Google Scholar
  9. Nathan, R. H. (1990): ‘FNS of the upper limb: targeting the forearm muscles for surface stimulation,’Med. Biol. Eng. Comput.,28, pp. 249–56CrossRefGoogle Scholar
  10. Peckham, P. H., Mortimer, J. T. andMarsolais, E. B. (1980): ‘Controlled prehension and release in the C5 quadriplegic elicited by functional electrical stimulation of the paralysed forearm musculature,’Ann. Biomed. Eng.,8, p. 369CrossRefGoogle Scholar
  11. Rushton, D. N. (1990): ‘Choice of nerves or roots for multichannel leg controller implant’in Popovic, D. B. (Ed.): ‘Advances in the external control of human extremities, X’ (Nauka, Belgrade) pp. 99–108Google Scholar

Copyright information

© IFMBE 1994

Authors and Affiliations

  • T. A. Perkins
    • 1
  • G. S. Brindley
    • 1
  • N. de N. Donaldson
    • 1
  • C. E. Polkey
    • 2
  • D. N. Rushton
    • 1
  1. 1.MRC Neurological Prostheses UnitLondonUK
  2. 2.Neurosurgical Unit, Maudsley HospitalLondonUK

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