Editing Prosthesis (section)

=====Microprocessor control=====
To mimic the knee's functionality during gait, microprocessor-controlled knee joints have been developed that control the flexion of the knee. Some examples are [[Otto Bock]]'s C-leg, introduced in 1997, [[Ossur]]'s Rheo Knee, released in 2005, the Power Knee by Ossur, introduced in 2006, the Plié Knee from Freedom Innovations and DAW Industries' Self Learning Knee (SLK).<ref>[http://www.daw-usa.com/Pages/SLK3.html "The SLK, The Self-Learning Knee"] {{Webarchive|url=https://web.archive.org/web/20120425081600/http://www.daw-usa.com/Pages/SLK3.html |date=2012-04-25 }}, DAW Industries. Retrieved 16 March 2008.</ref>

The idea was originally developed by Kelly James, a Canadian engineer, at the [[University of Alberta]].<ref>{{Cite news|url= https://www.nytimes.com/2005/06/20/health/menshealth/20marrbox.html |title = Titanium and Sensors Replace Ahab's Peg Leg |access-date=2008-10-30 |work= The New York Times |date= 2005-06-20 | first=Michel | last=Marriott}}</ref>

A microprocessor is used to interpret and analyze signals from knee-angle sensors and moment sensors. The microprocessor receives signals from its sensors to determine the type of motion being employed by the amputee. Most microprocessor controlled knee-joints are powered by a battery housed inside the prosthesis.

The sensory signals computed by the microprocessor are used to control the resistance generated by [[hydraulic cylinders]] in the knee-joint. Small valves control the amount of [[hydraulic fluid]] that can pass into and out of the cylinder, thus regulating the extension and compression of a piston connected to the upper section of the knee.<ref name=PikeAlvin>Pike, Alvin (May/June 1999). "The New High Tech Prostheses". InMotion Magazine 9 (3)</ref>

The main advantage of a microprocessor-controlled prosthesis is a closer approximation to an amputee's natural gait. Some allow amputees to walk near walking speed or run. Variations in speed are also possible and are taken into account by sensors and communicated to the microprocessor, which adjusts to these changes accordingly. It also enables the amputees to walk downstairs with a step-over-step approach, rather than the one step at a time approach used with mechanical knees.<ref name=MartinCraigW>Martin, Craig W. (November 2003) [http://www.ibrarian.net/navon/paper/Evidence_Based_Practice_Group__EBPG_.pdf?paperid=2575568 "Otto Bock C-leg: A review of its effectiveness"] {{Webarchive|url=https://web.archive.org/web/20161228231356/http://www.ibrarian.net/navon/paper/Evidence_Based_Practice_Group__EBPG_.pdf?paperid=2575568 |date=2016-12-28 }}. WCB Evidence Based Group</ref> There is some research suggesting that people with microprocessor-controlled prostheses report greater satisfaction and improvement in functionality, residual limb health, and safety.<ref name="Kannenberg 2014 1469–1496">{{cite journal |last1=Kannenberg |first1=Andreas |last2=Zacharias |first2=Britta |last3=Pröbsting |first3=Eva |title=Benefits of microprocessor-controlled prosthetic knees to limited community ambulators: Systematic review |journal=Journal of Rehabilitation Research and Development |date=2014 |volume=51 |issue=10 |pages=1469–1496 |doi=10.1682/JRRD.2014.05.0118 |pmid=25856664 |s2cid=5942534 }}</ref> People may be able to perform everyday activities at greater speeds, even while multitasking, and reduce their risk of falls.<ref name="Kannenberg 2014 1469–1496"/>

However, some have some significant drawbacks that impair its use. They can be susceptible to water damage and thus great care must be taken to ensure that the prosthesis remains dry.<ref>{{cite journal |last1=Highsmith |first1=M. Jason |last2=Kahle |first2=Jason T. |last3=Bongiorni |first3=Dennis R. |last4=Sutton |first4=Bryce S. |last5=Groer |first5=Shirley |last6=Kaufman |first6=Kenton R. |title=Safety, Energy Efficiency, and Cost Efficacy of the C-Leg for Transfemoral Amputees: A Review of the Literature |journal=Prosthetics and Orthotics International |date=December 2010 |volume=34 |issue=4 |pages=362–377 |doi=10.3109/03093646.2010.520054 |pmid=20969495 |s2cid=23608311 }}</ref>