Britton, David

Campbell, Gavin

Cleland, I

Cundell, Jill

Graham, Lorraine

Harting, Margit

Lee, Bernard

O'Connor, Goretti

Schofield, Trevor

Vincent, Jordan

English

Ulster University's Research Portal

                      Initial Trial of a Telemetric Monitoring System for Prosthesis Use following Lower LimbAmputationSchofield, T., Harting, M., Britton, D., Graham, L., Campbell, G., Lee, B., Cundell, J., Vincent, J., Cleland, I., &O'Connor, G. (2023). Initial Trial of a Telemetric Monitoring System for Prosthesis Use following Lower LimbAmputation. Poster session presented at 9th International Symposium on the Diabetic Foot, The Hague,Netherlands.Link to publication record in Ulster University Research PortalPublication Status:Published (in print/issue): 01/05/2023Document VersionPublisher's PDF, also known as Version of recordGeneral rightsCopyright for the publications made accessible via Ulster University's Research Portal is retained by the author(s) and / or other copyrightowners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with theserights.Take down policyThe Research Portal is Ulster University's institutional repository that provides access to Ulster's research outputs. Every effort has beenmade to ensure that content in the Research Portal does not infringe any person's rights, or applicable UK laws. If you discover content inthe Research Portal that you believe breaches copyright or violates any law, please contact pure-support@ulster.ac.uk.Download date: 01/07/2023The temperature profiles weredetermined by both the large areasensor close to the skin (externalsensor) and a sensor on the circuitboard inside the pod (internal sensor).The time scale is expressed as thepercentage (0 – 100) of the day frommidnight-to-midnight UTC.• Results of this Phase I study have indicated that the sensing platform is robust, and the data collected is reliable. Using the system, it is possible to obtain unbiased information concerning prosthesis wear.• Data from the study confirmed that, although a rule-based alerting strategy can be the same for all participants, each has their own baseline behaviour and characteristics. Hence the algorithms need to be personalised by implementing adaptive adjustment of the thresholds. • Predictive analysis techniques can highlight trends that may enable timely intervention.• Further developments will focus on applying machine learning to data collected in a Phase II trial to testa new provision of care for amputees.Affiliations1 Bioflex Yarns Ltd, Belfast N Ireland, United Kingdom2 Dept of Physics, University of Cape Town, Rondebosch 7701 Cape Town, South Africa3 Belfast Heath & Social Care Trust, Musgrave Park Hospital, Belfast N Ireland, United Kingdom4 Opcare Ltd, Belfast N Ireland, United Kingdom5 Ulster University, Belfast N Ireland, United Kingdom6 PST Sensors Europe Ltd, Sedgefield England, United KingdomIntroductionFor lower limb amputees, prosthesis use is critical for achievingindependent mobility and enhancing quality of life. However, use of aweight-bearing prosthesis is commonly associated with shear stresstrauma, inflammation, infection, and residual limb ulceration. Each year, upto 75% of amputees experience skin complications leading to cessation ofuse, often requiring clinical intervention. At 5 years, there is a 17% re-amputation rate. Diabetes affects up to 75% of amputees, with resultantsensory and immunological impairment, and is associated with latepresentation with advanced skin complications. Identification of skincomplications is currently based on subjective self-inspection, or routinely-scheduled clinical visits.In the residual limb, local temperature and moisture changes areassociated with the development of skin trauma and infection. In diabeticfoot studies, temperature changes have been shown to precede skinbreakdown. Potentially, changes in local temperature and moisture withinthe socket of a prosthesis can identify early skin inflammation, before theonset of ulceration. This may create the opportunity for an ‘early warning’indicator, to limit the progression of skin damage and to inform limbmanagement and rehabilitation planning. Direct skin monitoring of the limbwithin the prosthesis during use has proven problematic, and potentiallyunsafe.This study was developed to assess the feasibility of a prosthesis-basedsensor using standard communication protocols in transmitting real-timeanalysis of the socket environment.Objectives• To assess the functionality of the multimodal sensor system embedded in a polyethylene closed-cell foam (Pelite) liner in a lower limb prosthesis, during routine use.• To assess the transmission and communication of sensor data in routine prosthesis use.• To assess the correlation of the monitored sensor  parameters with the socket environment changes within the prosthesis.Methods20 established amputees recruited to a one-month trial. The wearable electronics sensor was built into the pelite liner, and had no direct skin contact. Participants were requested to provide daily socket comfort scores and report on difficulties concerning system or prosthesis.• 20 established transtibial amputees, living independently, requiring renewal of a patella-tendon bearing pelite socket liner. Enrolment for 4-week study period.• Multimodal sensor was embedded in the liner base, with a perforated pelite separator.• No direct skin contact.• Sensor data recorded at 10 minute intervals:o read-on-demand system, interrogated by the mobile phone, equipped with a multimodal sensing capabilityo large area temperature sensor, directly measuring the socket temperature, o environment reference temperature sensor o humidity sensor, o three-axis accelerometero raw data in native format transmitted in the Bluetooth.o mobile phone provides a time-stamp and GPS information.• Bluetooth data communication to mobile phone app and cloud.• Daily Socket Comfort Score and ‘problem’ record.• Offline Post-study exploratory data analysis.ResultsConclusionsInitial Trial of a Telemetric Monitoring System for Prosthesis Use following Lower Limb Amputation.20 participants recruited:• 3 participants withdrew – (study coincided with Covid pandemic).• 1 participant deceased prior to commencement.• 1 sensor system malfunction – use of concurrent silastic liner.15 participants studied: • 4 experienced data loss due to mobile phone signal interruption• During study, 2 had prosthesis discomfort + 2 had skin inflammation leading to cessation of use.• In total, 66 weeks of data were obtained for analysis. Sensor Data Reliability:• Sensor ‘drop-out’ rates and missing data values averaged 5-6% overall. • The battery level of all sensors was stable over the course of the study.Enhanced activity in the afternoon, until 18:00, iscorrelated with the change in temperature. Themobility, defined as the total distance travelled inthe last hour determined from cell phone GPS,shows a similar behaviour indicating walkingactivity. Exercise is accompanied by a steadyincrease in humidity. As expected, activity leadsto an increase in limb temperature, and henceincreased socket temperature. Ten participantsshowed a temperature rise, lagging behindactivity, which continued at least 30 minutes afteractivity ceased. In contrast eight participantsexhibited a considerable temperature increase,independent of activity. Of these, five haddiscontinued prosthesis wear within two daysafter that event, citing SKIN PROBLEMS.These observations have allowed thedevelopment of other performance metrics,including the lag between activity and sockettemperature and the lag between the referenceand socket temperatures, both derived fromnormalised differences. The latter also proved tobe an excellent indicator of whether theprosthesis is being worn or not.Figure 1. a) temperature averaged for individual days in the week over the entire monitoring time, b) activity throughout the day, averaged over all days. a) b)INDIVIDUAL DATAPatterns of temperature, humidity, mobility and activity were obtained for each participant. Below is a sample analysis from one participant chosen at randomDATA ANALYSIS   ACTIVITY & TEMPERATURE data reflected the different patterns of prosthetic use, and the pattern of diurnal variation. Examples:This study is supported by Innovate UK project “Non-Invasive Telemetric Sensing for Lower Leg Amputee Surface Skin Management” (project number 103947)Figure 2: Participant P05 (chosen at random as anexample): Temperature, humidity, activity, and mobilityfor a 24-hour period.Schofield T 1, Harting M 2,6 , Britton D 2,6 , Graham L 3 , Campbell G 3,4 , Lee B 1,5 , Cundell J 3,5 , Vincent J5 , Cleland I 5 , O'Connor G 1

Initial Trial of a Telemetric Monitoring System for Prosthesis Use following Lower Limb Amputation

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Initial Trial of a Telemetric Monitoring System for Prosthesis Use following Lower Limb Amputation

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