Multiple-Input Single-Output Closed-Loop Isometric Force Control Using Asynchronous Intrafascicular Multi-Electrode Stimulation

作者：Frankel Mitchell A^*; Dowden Brett R; Mathews V John; Normann Richard A; Clark Gregory A; Meek Sanford G

来源：IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2011, 19(3): 325-332.

DOI：10.1109/TNSRE.2011.2123920

• Control strategies
• medical robotics
• peripheral nerve
• neuro-motor interfaces

Although asynchronous intrafascicular multi-electrode stimulation (IFMS) can evoke fatigue-resistant muscle force, a priori determination of the necessary stimulation parameters for precise force production is not possible. This paper presents a proportionally-modulated, multiple-input single-output (MISO) controller that was designed and experimentally validated for real-time, closed-loop force-feedback control of asynchronous IFMS. Experiments were conducted on anesthetized felines with a Utah Slanted Electrode Array implanted in the sciatic nerve, either acutely or chronically (n = 1 for each). Isometric forces were evoked in plantar-flexor muscles, and target forces consisted of up to 7 min of step, sinusoidal, and more complex time-varying trajectories. The controller was successful in evoking steps in force with time-to-peak of less than 0.45 s, steady-state ripple of less than 7% of the mean steady-state force, and near-zero steady-state error even in the presence of muscle fatigue, but with transient overshoot of near 20%. The controller was also successful in evoking target sinusoidal and complex time-varying force trajectories with amplitude error of less than 0.5 N and time delay of approximately 300 ms. This MISO control strategy can potentially be used to develop closed-loop asynchronous IFMS controllers for a wide variety of multi-electrode stimulation applications to restore lost motor function.

• 出版日期2011-6