(e-book) Rehabilitation Robotics (by Sashi S _部分12(17)

康复机器人相关的论文,拆分成了13份文档,都很不错的。

Synthesis of Prosthesis Architectures and Design of Prosthetic Devices for Upper Limb Amputees 557 processed by a programmable electronic circuit which carries out the control strategy to operate the device. Rechargeable batteries power all thes e components . Some passive friction joints are sometimes included in the system and are useful to give the pros thetic limb an optimal pre-determined configuration when performing certain tas ks. The pas s ive joints are operated by applying external forces by means of the sound limb or resting the artificial segments on fixed points, before or after the action of the active joints.

Currently, the mos t common electromechanical pros thetic components available on the market are many kinds of terminal devices (each with one degree of freedom – DoF – for gras ping), the elbow joint, the wris t prono-s upination unit (which allows the terminal device to rotate around the longitudinal forearm axis ), and the wris t flexion unit. Many other active articulations have been studied and proposed as prototypes but they have not yet been dis tributed commercially. Among the recent interes ting res earch res ults , the authors would like to mention: the multi-fingered pros thetic hands (Kyberd et al., 2001; Pons et al., 2004; Yang et al., 2004), which provide the terminal device with more than one DoF, thus making different grip patterns available (one of thes e s eems ready to be commercialized 1); a powered humeral rotator (Weir & Grahn, 2005) which allows the forearm segment to rotate around the longitudinal humeral axis (this is a novelty, because most above-elbow prostheses are equipped with passive humeral rotators); a shoulder joint with one DoF for upper arm elevation (Gow et al., 2001); a s houlder joint with two DoFs which is bas ed on a differential mechanis m and provides upper arm elevation and abduction (Cattaneo et al., 2001).

There are several ways of controlling electrically-powered prostheses, the most popular being myoelectric control: electromyographic ignal (EMG, i.e. electrical ignal a ociated with the mu cle contraction ), mea ured on the kin by myoelectric electrodes located in the socket, are properly amplified and filtered, and then processed by the controller that s witches the motors on or off in the active joints to produce movement s and function s . Although theoretically po s s ible, the simultaneous and independent contraction of distinct bundles of muscles, that would generate EMG signals able to operate different functions at the same time is very difficult and stressing for the patient. The myoelectric control s cheme is therefore generally bas ed on the s equential activation of the pros thetic articulations one at a time, res ulting in a not very natural control. In this context, s ome recent res ults s eem to be promis ing to overcome this limitation (Kuiken et al., 2004).

The good qualities of this pros thes is are s ufficient functionality, good performance and a pleas ant appearance. The critical as pects are the weight and the volume of the phys ical structure, and the intricate control, due to the sequential activation of both the active and passive joints. Finally, it is proven that electrically-powered prostheses provide a high level of technology but at a high cost.

1.3 Ne w prosthesis design and overvie w of the presented method

In order to provide high level disarticulated patients with a comfortable, humanlike and user-friendly prosthesis, not all the physiological joint movements can be replicated, thus limiting the functionality of the artificial arm. When compared to the human arm, the 1 /page.php?pageid=12&section=3.