Micromodular implants to provide electrical stimulation of paralyzed muscles and limbs

Cameron, Tracy; Loeb, Gerald E.; Peck, R.A.; Schulman, Joseph H.; Strojnik, P.; Troyk, Philip R.

doi:10.1109/10.623047

Cited by 123 publications

(43 citation statements)

References 31 publications

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“…in conclusion, as FED implantation technology continues to advance (PERKINS et al, 1996;CAMERON et al, 1997), and developments in natural sensors persist (HAUGLAND and SINKJAER, 1995), there appears to be an overall evolutionary process towards the ideal of a neural prosthesis which is seamlessly integrated with the human motor system. Based on experiences to date, it is justifiable to anticipate that finite state control, or a descendant thereof, will play an important role in the control of these systems.…”

Section: Discussionmentioning

confidence: 94%

“…These developments, coupled with those in natural sensors (HAUGLAND and SINKJAER, 1995) and implanted stimulators (STROJNIK et at., 1990;PERKINS et at., 1996;CAMERON et at., 1997), are driving an overall evolutionary process towards automatically controlled neural prostheses, whose characteristics are approaching those of the natural human neuro-motor system, it is proposed that this evolution is following the ideal of a 'human' controller, a fully implanted control system which operates seamlessly and symbiotically with the human neuromotor system to compensate for any pathologies present.…”

Section: Introductionmentioning

confidence: 93%

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Finite state control of functional electrical stimulation for the rehabilitation of gait

Sweeney

Lyons

Veltink

2000

Med. Biol. Eng. Comput.

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Finite state control is an established technique for the implementation of intention detection and activity co-ordination levels of hierarchical control in neural prostheses, and has been used for these purposes over the last thirty years. The first finite state controllers (FSC) in the functional electrical stimulation of gait were manually crafted systems, based on observations of the events occurring during the gait cycle. Subsequent systems used machine learning to automatically learn finite state control behaviour directly from human experts. Recently, fuzzy control has been utilised as an extension of finite state control, resulting in improved state detection over standard finite state control systems in some instances. Clinical experience over the last thirty years has been positive, and has shown finite state control to be an effective and intuitive method for the control of functional electrical stimulation (FES) in neural prostheses. However, while finite state controlled neural prostheses are of interest in the research community, they are not widely used outside of this setting. This is largely due to the cumbersome nature of many neural prostheses which utilise externally mounted gait sensors and FES electrodes. FES-based control of movement has been subject to the constraints of artificial sensor and FES actuator technologies. However, continued advances in natural sensors and implanted multi-channel stimulators are broadening the boundaries of artificial control of movement, driving an evolutionary process towards increasingly human-like control of FES-based gait rehabilitation systems.

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Section: Discussionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 93%

Finite state control of functional electrical stimulation for the rehabilitation of gait

Sweeney

Lyons

Veltink

2000

Med. Biol. Eng. Comput.

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“…1 A number of approaches, including gene and drug therapies, are currently being pursued in the hope of preventing blindness. 2,3 in paraplegics and quadriplegics [9][10][11] as well as to suppress intractable pain 12 and Parkinsonian tremor. 13 …”

Section: Historical Overview and Current Approachesmentioning

confidence: 99%

Intraocular retinal prosthesis

Weiland

Humayun

2006

IEEE Eng. Med. Biol. Mag.

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Purpose: An electronic implant that can bypass the damaged photoreceptors and electrically stimulate the remaining retinal neurons to restore useful vision has been proposed. A number of key questions remain to make this approach feasible. The goal of this thesis is to address the following 2 specific null hypotheses: (1) Stimulus parameters make no difference in the electrically elicited retinal responses. (2) Just as we have millions of photoreceptors, so it will take a device that can generate millions of pixels/light points to create useful vision.Methods: For electrophysiologic experiments, 2 different setups were used. In the first setup, charge-balanced pulses were delivered to the retinal surface via electrodes inserted through an open sky approach in normal or blind retinal degenerate (rd) mice. In the second setup, the rabbit retina was removed under red light conditions from an enucleated eye and then maintained in a chamber while being superfused with oxygenated, heated Ames media. In both setups, stimulating electrodes and recording electrodes were positioned on the retinal surface to evaluate the effect of varying stimulation parameters on the orthodromic retinal responses (ie, recording electrode placed between stimulating electrodes and optic nerve head).For psychophysical experiments, visual images were divided into pixels of light that could be projected in a pattern on the retina in up to 8 sighted volunteers. Subjects were asked to perform various tasks ranging from reading and face recognition to various activities of daily living.Results: Electrophysiologic experiments: In a normal mouse, a single cycle of a 1-kHz sine wave was significantly more efficient than a 1-kHz square wave (P <.05), but no such difference was noted in either of the 8-or 16-week-old rd mouse groups (8-week-old, P =.426; 16-week-old, P =.078). Charge threshold was significantly higher in 16-week-old rd mouse versus both 8-week-old rd and normal mouse for every stimulus duration (P <.05). In all groups, short duration pulses (40, 80, and 120 s) were more efficient in terms of total charge (the product of pulse amplitude and pulse duration) than longer (500 and 1,000 s) pulses (P <.05). In all groups, applying a pulse train did not lead to more efficient charge usage (P <.05).Psychophysical experiments: In high-contrast tests, facial recognition rates of over 75% were achieved for all subjects with dot sizes of up to 31.5 minutes of arc when using a 25 x 25 grid with 4.5 arc minute gaps, a 30% dropout rate, and 6 gray levels. Even with a 4 x 4 array of pixels, some subjects were able to accurately describe 2 of the objects. Subjects who were able to read the 4-pixel letter height sentences (on the 6 x 10 and 16 x 16 array) seemed to have a good scanning technique. Scanning at the proper velocity tends to bring out more contrast in the lettering. The reading speed for the 72-point font is a bit slower than for the next smaller font. This may be due to the limited number of letters (3) visible in the window with t...

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“…Coordination of movements by FES requires electronic stimulators that are self-contained with a low power consumption, small, and light and must have the simplest possible interface [e.g., [16][17][18][19][20][21][22][23][24]. The stimulator should be programmable.…”

Section: Electronic Nerve Stimulatorsmentioning

confidence: 99%