Modernising trans-radial prosthetic socket creation with digital methods

Lead Research Organisation: Newcastle University
Department Name: Sch of Engineering

Abstract

It is estimated that globally 20-25% of all amputations are upper-limb, and approximately 1 in every 2500 children are born with upper-limb deficiency. Despite this, advances in upper-limb prosthetics, in particular the socket, have been slow and currently patients are often left with unsatisfactory and unreliable devices. The socket is a crucial part of the prostheses - it must be unique, comfortable and appropriate for the amputee's lifestyle. Socket-fitting is time-consuming and requires several visits to specialised clinics, often far from home. Currently, manufacturing sockets is extremely laborious and takes up lots of clinician time.
Myoelectric (electronically operated) devices are a sub-type of upper limb prostheses that are not currently funded on the NHS. To use a myoelectric hand, the prosthetic socket must have electrodes which detect nerve impulses under the skin. The signals from the nerves are the 'instructions' to the prosthetic hand. Short term illnesses and water retention can cause significant changes in limb volume and therefore poor-fitting sockets; this contributes to low-quality signals and unpredictable reactions from the prosthetic hand, which can cause amputees to abandon their devices entirely.
Multiple systematic reviews of the prosthetics field have highlighted a need for more clinically validated studies into novel socket designs. Several novel upper-limb socket designs exist, but often have only been tested for their effect on the factor they were designed to improve, or not tested clinically at all.

Research Aim: The aim of this research is to take a holistic approach to creating and testing a novel design of upper limb socket. The research goals of the project can be categorised to:
I. Use modern manufacturing methods to create a novel upper-limb socket that includes adjustability, myoelectric control and anatomical contouring.
II. Test the socket with volunteers to see its effect on the electrode-body and socket-body interfaces.
III. Incorporate a feedback mechanism into the socket using sensor technology, to assess and quantify the effects on the remaining limb of having an adjustable and optimised socket design.
Objectives: A digital method of creating sockets will be devised utilising 3D scanning, 3D printing and modern materials to reduce the time and cost it takes to create a socket using traditional processes such as casting and lamination. The effects of different socket modifications will be assessed for their impact on control, comfort and patient satisfaction through a series of prototype designs and test rigs. A prototype adjustable socket will be created based on various existing socket designs and tested with volunteers experiencing trans-radial limb loss/deficiency. Using the feedback from the volunteers, the design will be refined and adapted to include electrodes for myoelectric control. Volunteers will be recruited for a study to compare the novel socket against a traditional socket to show whether myoelectric control reliability, comfort and other factors are improved with the novel design. After refining the myoelectric socket, various sensors will be included in the design as a feedback mechanism to help quantify the effect the novel socket has on the limb.

Publications

10 25 50

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Olsen J (2022) Does Trans-radial Longitudinal Compression Influence Myoelectric Control? in Canadian prosthetics & orthotics journal

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Olsen J (2021) 3D-Printing and Upper-Limb Prosthetic Sockets: Promises and Pitfalls. in IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society

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Olsen J (2021) Remote creation of clinical-standard myoelectric trans-radial bypass sockets during COVID-19. in Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference

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Olsen J (2022) The Impact of Limited Prosthetic Socket Documentation: A Researcher Perspective. in Frontiers in rehabilitation sciences

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509528/1 30/09/2016 30/03/2022
2281137 Studentship EP/N509528/1 30/09/2019 30/03/2023 Jennifer Olsen
EP/R51309X/1 30/09/2018 29/09/2023
2281137 Studentship EP/R51309X/1 30/09/2019 30/03/2023 Jennifer Olsen
 
Title Sea-bed 3D prints created for the "Seascapes" project 
Description A national heritage lottery funded project ("seascapes") required 3d printed sea-bed scans, which had been acquired by their divers. I took the scans, generated a model which is now on display at Hartlepool museum and was displayed at the tall ships race, and showed the team how to generate their own models. I was able to do this thanks to the additive manufacturing skills I had acquired through my award. 
Type Of Art Artefact (including digital) 
Year Produced 2023 
Impact My contribution helped the scans go on display at a large public event and are now live-3d printed in the museum, engaging members of the public. 
 
Description This award investigates upper limb prosthetic sockets, particularly those myoelectric devices (bionic arms) - the current key findings are:

1) The current methods used to create prosthetic limbs are not adequately documented.
2) Digital methods (i.e. 3D scanning and 3D printing) are misrepresented in the media and literature, and are not currently capable of directly replacing traditional socket manufacturing methods.
3) Upper limb prosthetics can be created remotely with the involvement of a trained clinician.
4) There is a need for comprehensive published documentation concerning the aspects of socket design and construction that presently rely on tacit knowledge. There is a necessity for a precise, universally acknowledged definition of what constitutes an optimal socket fit, distinguishing it from just "comfort", grounded in a thorough comprehension of both clinician and user perspectives. A universally accepted criteria for assessing the fit of a prosthetic socket and promoting improved data exchange between clinical settings and research is currently not available.
5)In a uniformly distributed 4-bar socket simulator, longitudinal compression neither hindered or enhanced single-channel EMG or fatigue resistance of wrist extensors during intense, brief contractions. When applied tangentially to the muscle, longitudinal compression aids in sustaining consistent contact between the skin and the socket on opposing sides. Consequently, sockets with longitudinal compression may enhance multi-channel EMG control, particularly in a configuration where EMG sensors are integrated into the compression struts.
6)Before digital scanning to capture tissue compliance, longitudinal compression can be applied via the use of an external device. Subsequently, custom-made devices (e.g. prosthetic sockets) can be crafted using these scans, aligning pre-made components in CAD software with reference points from longitudinal compression hardware, allowing custom medical devices made using a "hands-off" method which also take into account tissue compliance. In a preliminary study, it was discovered that high-pressure longitudinal compression of the forearm surpassed low-pressure longitudinal compression in reducing electromyography disturbances that trigger false activations of a prosthetic device. This effect was particularly notable when the device operated at the extremities of the arm's range of motion, suggesting that this socket style could prevent or reduce the "limb position effect" (where bionic limbs no longer function as expected when used in certain positions). While wearing the high-pressure cuff, the maximum recorded muscle amplitude (target muscle) during contraction decreased, whereas the antagonist (opposing muscle) activity slightly increased. This suggests that longitudinal compression devices may influence the exertion required by wearers to perform contractions, yet they also pose the potential to inadvertently heighten the risk of co-contractions (where both muscles are classed as "active" at once).

For non technical audiences, electromyography/emg is the detection of electrical activity in our muscles which can be turned into a control signal for various devices, including prosthetic devices (e.g. bionic hands). Longitudinal compression is where depressor bars run parallel to the radius/ulna of the forearm and depress the soft tissue underneath, to stabilise the limb.
Exploitation Route In relation to the findings above:
1) A uniform, systematic method of reporting prosthesis creation could be created, to assist sharing of techniques and knowledge.
2) Investigating digital methods for creating prosthetic sockets which incorporate the 'feel' of the limb, instead of hands-off scanning.
3) The development of a home-based socket creation system for patients who cannot travel.
4) Further resesarch into the effects of longitudinal compression on the reliability of EMG control
5) Socket creation systems that rely on pre-fabricated depressor blocks + digital scanning.
Sectors Healthcare

Other

 
Description UKCAS Travel Award
Amount £300 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start  
End 12/2019
 
Description Appeared in Dr Shini Somara's podcast (eSTEAMd) and youtube channel 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Featured on Dr Shini somara's podcast and youtube channel discussing my PhD work.
Year(s) Of Engagement Activity 2021
URL https://www.facebook.com/drshinisomara/videos/this-week-i-chat-with-jenny-olsen-a-biomedical-enginee...
 
Description Created an educational video about prosthetics with Dr Shini Somara for youtube 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Created a youtube video to educate the public about prosthetics (my PhD work) which was shared on several social media platforms.
Year(s) Of Engagement Activity 2023
URL https://www.youtube.com/watch?v=yz4GMd8Tisw
 
Description Featured in "Engineers making a difference" book 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact I was featured in a book for the work I did during my PhD which was distributed to every secondary school in the UK.
Year(s) Of Engagement Activity 2023
URL https://www.amazon.co.uk/Engineers-Making-Difference-Technicians-Entrepreneurs/dp/1804660272
 
Description Interviewed for local news after winning a WE50 award 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact I was interviewed by local news outlets after winning a top 50 women in engineering award as a result of my PhD work.
Year(s) Of Engagement Activity 2021
URL https://www.sunderlandecho.com/news/people/sunderland-engineer-dedicates-top-engineering-award-to-he...
 
Description School visits, online "visits" and panel talks about my PhD research (several) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact I spoke at several schools, museum events, science events/festivals and online events regarding my PhD work, engaging members of the public of all ages.
Year(s) Of Engagement Activity 2019,2020,2021,2022,2023
 
Description spoke at several open days about life as a PhD student 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I spoke at several open days about my life as a PhD student and why I enjoy my work, and then directly spoke to many open day attendees. This helped them decide whether they would also like to study a research degree.
Year(s) Of Engagement Activity 2019,2020,2021