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A DSP-based Neural Controller for a Multi-degree Prosthetic Hand
Published in Hongxing Li, C.L. Philip Chen, Han-Pang Huang, Fuzzy Neural Intelligent Systems, 2018
Hongxing Li, C.L. Philip Chen, Han-Pang Huang
The myoelectrically controlled prostheses provide amputees extra prosthetic options. However, most commercial prosthetic hands (e.g., Steeper Electric Hand, Otto Bock System Electric Hand, Swedish Systemteknik Hand) [2] are one degree of freedom grippers that are controlled by one or two channels of electromyographic (EMG) signals. Their surface electrodes were placed on the antagonist muscles. When the muscle tension reaches a threshold value, the prosthetic hands generate a digital on/off switch to control a motor to direct the hand in one direction or another. An alternate way is simple proportional control in terms of EMG signal [16]. The proportional control provides the user less sensitive and faster control of the hand, depending on the strength of muscle contraction. Proportional myoelectric control has been used in the Utah artificial arm [9]. Those EMG controlled systems mentioned above limit the ability of manipulation. Recently, a number of advanced dexterous robot hands have been successfully developed. A few of them can be used in prosthetics [8, 12, 13, 17]. A modular prosthetic hand was developed by [5, 13]. They are multi-fingered prosthetic hands capable of performing a variety of prehensile postures, including different grasp modes (e.g., power grasp, hook grasp, cylindrical grasp, three-jaw chuck, etc.). Nevertheless, how to control a multifunctional prosthetic hand using an EMG signal is the most difficult problem.
Prosthetic and orthotic devices
Published in Alex Mihailidis, Roger Smith, Rehabilitation Engineering, 2023
Joel Kempfer, Renee Lewis, Goeran Fiedler, Barbara Silver-Thorn
Recent advances in upper extremity componentry include externally powered prosthetic hands that incorporate independent finger movement and variable grasp patterns, with proportional myoelectric control (Segil 2013; Al-Timemy et al. 2015). These devices include the i-Limb (Touch Bionics), Bebionic (RSL Steeper), and Michelangelo (Otto Bock) hands. Recent versions may also be fitted on partial hand amputees.
A review on the advancements in the field of upper limb prosthesis
Published in Journal of Medical Engineering & Technology, 2018
Nilanjan Das, Nikita Nagpal, Shailee Singh Bankura
A simple example of proportional myoelectric control is a system in which the EMG from flexors and extensors of the user’s forearm is measured, amplified, filtered and smoothed by two active electrodes. This provides estimates of EMG amplitudes that can be sent to a hand controller. After applying thresholds to remove uncertainty at low contraction levels, the controller sets a voltage applied to the motor that is proportional to the contraction intensity (Sears and Shaperman 1991) [70]. This functionality is essentially offered by several manufacturers of commercial prostheses. Simultaneous control, as opposed to sequential control, is hypothesised to be the most intuitive control system to handle for the prosthesis user. Sequential control is, on the other hand, deemed as slow and inconvenient by many users, but it is today the only method available in commercial multifunction prostheses. A real-time implementation of a control system with simultaneous proportional myoelectric control is associated with dual function prosthesis. The method includes prosthesis-guided training, and the assessment required development of a novel prosthesis socket equivalent for use by normally-limbed subjects.