Limb prosthetics

Other artificial muscle applications have been demonstrated as well. Carpi et al. used helical contractile linear actuators and buckling actuators to actuate eyeballs for use in an android face [258, 268, 269]. Another eyeball actuator has been developed by Liu et al. based on their inflated actuator design their actuator is capable of generating eyeball rotations from —50 to 50 [241]. Kombluh et al. have also reported on a mouth driven by a DE actuator [4]. Biddis and Chau have provided a good review on the challenges and opportunities of DE actuators for upper limb prosthetics [270]. 

Biddis E, Chau T (2008) Dielectric elastomers as actuahus fOT upper limb prosthetics challenges and opportunities. Med Eng Phys 30 403... 

Schmidl, H., The importance of information feedback in prostheses for the upper limbs. Prosthet. Orthot Int, 1977.1 21-24. 

Murdoch, G. and Donovan, R.G. (Eds.). 1988. Amputation Surgery and Lower Limb Prosthetics. Boston, Blackwell Scientific Pubhcations. 

Schuch, C.M., A guide to lower limb prosthetics. Part I— Prosthetic design Basic concepts. From www.amputeecoalition.orq/inmotion/mar apr 98/pros primer/paqe2.html... 

The major factors limiting prosAeses to tools are practical ones due to the severe weight, power, and size constraints of hand/atm systems as well as the difficulty in finding a sufficient number of appropriate control sources to control the requisite number of degrees of freedom. Of these, it is the lack of independent control sources that imposes the most severe impediment to the development of today s prosthetic hand/atm systems. As a result, upper-limb prosthetics research is somewhat dominated by considerations of control. Still, the importance of better actuators and better multifunctional mechanisms must not be ignored. Control is useless if effective hand and arm mechatusms are not available. 

Second, this fitting demonstrates the highly modular nature of upper-limb prosthetics today— components from many different manufacturers were used in a mix-and-match approach to obtain the most functional set of prostheses for the user. 

Although the physical design constraints of weight, volume, and power are severe, they are not so severe that multifunctional arms and hands cannot be built that would be of acceptable weight and size. The real problem is, as has been alluded to before, the issue of how to interface a multifunctional arm or hand to an amputee in a meaningful way. It is for this reason that upper-limb prosthetics is often dominated by consideration of control. That is, how can the prosthesis be controlled in such a fashion that it will be an aid rather than a burden to the user ... 

Blair S. J., and Kramer, S. (1981). Partial-hand amputation. Atlas of Limb Prosthetics Surgical and Prosthetic Principles, chap. 10, American Academy of Orthopaedic Surgeons (AAOS.), C. V. Mosby Co., St. Louis, pp. 159-173. 

Bowker, J. H., and Michael, J. W. (eds.) (1992). Atlas of Limb Prosthetics, Surgical, Prosthetic, and Rehabilitation Principles, 2d ed., Mosby-Year Book, Ine., Sl Louis, Mo. 

Childress, D. S. (1985). Historical aspects of powered limb prosthetics. Clinical Prosthetics and Orthotics, no. 9,pp. 2-13. 

Several groups have used computer models of the residual limb to investigate the residual limb-prosthetic socket interface. Many investigators have also used finite-element modeling of the residual limb and the prosthetic socket of lower extremity amputees to investigate residual limb-prosthetic socket biomechanics and to estimate the interface stress distribution (for review, see refs. 38, 46, and 47). 

Finally, finite-element models have potential sqiplicability in CAD of prosthetic sockets. Current prosthetic CAD systems emulate the hand-rectification process, whereby the socket geometry is manipulated to control the force distribution on the residual limb. Incorporation of the finite-element technique into future CAD would enable prescription of the desired interface stress distribution (i.e., based on tissue tolerance). The CAD would then compute the shape of the new socket that would theoretically yield this optimal load distribution. In this manner, prosthetic design would be directly based on the residual limb-prosthetic socket interface stresses. 

The residual limb-prosthetic socket stresses are influenced by the fit of the socket and the alignment of the prosthesis. For transdbial amputees, medial-lateral stability is influenced by foot placement. Foot inset (or outset) may result in varas (or valgus) moments applied to the limb. Similarly, anterior-posterior stability is influenced by the fore-aft position (extension-flexion moment) of the foot, foot plantarflexion/dorsiflexion (extension-flexion moment), and heel durometer (soft heel increases foot plantarflexion). For transtibial amputees with normal knee extensors, knee flexion moments on heel strike are desired, as for individuals without amputation. 

Lower- and Upper-Limb Prosthetics and Orthotics, 1992, Northwestern University Medical School, Prosthetic Orthotic Center, Chicago. 

American Academy of Orthopedic Surgeons, (1981), Atlas of Limb Prosthetics Surgical and Prosthetic Principles, Mosby, St Louis. 

Biddiss, E. and Chau, T. (2008). Dielectric elastomer as actuators for upper limb prosthetics Challenges and opportrmities, Medical Engineering Physics 30, pp. 403-418. 

Biddiss E, Chau T, Upper-limb prosthetics Critical factors in device abandonment, American Journal of Physical Medicine Rehabilitation, vol. 86, p>p. 977-987,2007. 

Pitkin, Mark R. Biomechanics of Lower Limb Prosthetics. New York Springer, 2010. Looks at the design of prosthetic devices from a biomechanical approach. 

Application of EPAM for limb prosthetics and orthotics still requires significant further development of the EPAM technology in order to address issues in scaling up stroke and force, as well as packaging issues related to reliability and safety at relatively high power levels (compared to most other applications discussed here). However, the fundamental demonstrated performance of EPAM in smaller devices shows the promise of this artificial muscle technology. The performance on a per mass and per volume basis demonstrated in smaller devices is sufficient to create actuators that can replace or augment the function of natural muscle. Other characteristics of EPAM that make EPAM well suited for such limb prosthetic and orthotic applications include ... 

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