RR - Draft 2

The webpage "Hero Arm" from Open Bionics (n.d.) introduces the Hero Arm prosthetic. The Hero Arm is a bionic upper-limb prosthetic that emulates the abilities of a regular human arm. Operating using myoelectric control, the Hero Arm uses electromyographical (EMG) electrode sensors to pick up tiny electrical signals from the user’s arm muscles. "Muscle contractions of different strengths, as reflected by different amplitudes", can differentiate between actions to be performed, such as "hand closing and opening or elbow flexion and extension" (Sörnmo & Laguna, 2005). Using the amplitude of the signals received, the Hero Arm translates these into coded instructions, which dictate its movement and actions. About its features, according to Open Bionics (n.d.) the Hero Arm is can perform a multitude of different grips, allowing users to perform actions such as eating with utensils, brushing their teeth, and much more. It also features a 180° rotatable wrist for added flexibility, as well as a "Freeze Mode" which locks the arm in place and disables muscle control, allowing the user to relax without fear of misinput or accidentally releasing their grip. While there are other bionic prosthetics in the medical field that are more technically advanced, the Hero Arm still shines in comparison due to its comfort, intuitive use, accessibility and affordability.

When considering a prosthetic, one major factor that comes to mind is comfort, which the Hero Arm achieves. In terms of build quality, the Hero Arm's liner is 3D printed using "a soft, flexible elastomer", enabling it to adapt seamlessly to the contours of any users' arms. It also has a fluted design, allowing for easy donning and doffing. Breathable vents are also implemented along the liner, enabling air circulation and helping the user stay cool. The liner is fully detachable from the arm's electronic components, which allows for ease of washing. The integral BOA™ fit adjustment dial allows the user to tighten and loosen the arm to their preferences and comfort. Most excitingly, the Hero Arm features MagSwap™ Removable Covers, which are magnetic covers that allow users to change the design of their arm in a flash, giving them great customisability and an outlet for self-expression. Regarding intuitive use, the myoelectric control of the Hero Arm allows it to be controlled by the user’s mind, which would allow the user to control it as if it were their biological arm. Additionally, Open Bionics made the code open source, allowing users to customise the controls of the Hero Arm according to their preferences.

Besides the Hero Arm's ease of use, its main advantages lie in its accessibility and affordability. Consumers can simply visit the Open Bionics website and register to get one, with its dimensions being tailor-made to suit their arm size. As for the Hero Arm's price, while there are no official prices as each custom-made arm will have its own costs, users of a Hero Arm based in the US recalled that it would cost approximately 12000 USD, but may be cheaper in other locations. Considering the prices of other upper limb bionic prostheses range between 15000-20000 USD, the Hero Arm is definitely more affordable while maintaining its functionality and reliability.

- mention affordability

- mention competition, compare to more medically professional models

- compare EMG to better methods

- why is it still good despite its shortcomings

 Thesis: The Hero Arm is amongst the best bionic prosthetics available to the public, being adeptly functional and affordable.

https://openbionics.org/affordableprosthetichands/

https://www.sciencedirect.com/topics/medicine-and-dentistry/myoelectric-control#:~:text=Myoelectric%20signals%20are%20typically%20measured,the%20process%20producing%20additive%20noise.