Innovative intelligent insole system reduces diabetic foot ulcer recurrence at plantar sites: a prospective, randomised, proof-of-concept study

Monitoring of Dynamic Plantar Foot Temperatures in Diabetes with Personalised 3D-Printed Wearables

Diabetic foot ulcers (DFUs) are a life-changing complication of diabetes that can lead to amputation. There is increasing evidence that long-term management with wearables can reduce incidence and recurrence of this condition. Temperature asymmetry measurements can alert to DFU development, but measurements of dynamic information, such as rate of temperature change, are under investigated. We present a new wearable device for temperature monitoring at the foot that is personalised to account for anatomical variations at the foot. We validate this device on 13 participants with diabetes (no neuropathy) (group name D) and 12 control participants (group name C), during sitting and standing. We extract dynamic temperature parameters from four sites on each foot to compare the rate of temperature change. During sitting the time constant of temperature rise after shoe donning was significantly (p < 0.05) faster at the hallux (p = 0.032, 370.4 s (C), 279.1 s (D)) and 5th metatarsal head (p = 0.011, 481.9 s (C), 356.6 s (D)) in participants with diabetes compared to controls. No significant differences at the other sites or during standing were identified. These results suggest that temperature rise time is faster at parts of the foot in those who have developed diabetes. Elevated temperatures are known to be a risk factor of DFUs and measurement of time constants may provide information on their development. This work suggests that temperature rise time measured at the plantar surface may be an indicative biomarker for differences in soft tissue biomechanics and vascularisation during diabetes onset and progression.

In-shoe pressure thresholds for people with diabetes and neuropathy at risk of ulceration: A systematic review

INTRODUCTION

In-shoe pressure thresholds play an increasingly important role in the prevention of diabetes-related foot ulceration (DFU). The evidence of their effectiveness, methodological consistency and scope for refinement are the subject of this review.

METHODS

1107 records were identified (after duplicate removal) based on a search of five databases for studies which applied a specific in-shoe pressure threshold to reduce the risk of ulceration. 37 full text studies were assessed for eligibility of which 21 were included.

RESULTS

Five in-shoe pressure thresholds were identified, which are employed to reduce the risk of diabetes-related foot ulceration: a mean peak pressure threshold of 200 kPa used in conjunction with a 25% baseline reduction target; a sustained pressure threshold of 35 mm Hg, a threshold matrix based on risk, shoe size and foot region, and a 40-80% baseline pressure reduction target. The effectiveness of the latter two thresholds have not been assessed yet and the evidence for the effectiveness of the other in-shoe pressure thresholds is limited, based only on two RCTs and two cohort studies.

CONCLUSIONS

The heterogeneity of current measures precludes meta-analysis and further research and methodological standardisation is required to facilitate ready comparison and the further development of these pressure thresholds.

Effect of tap dance on plantar pressure, postural stability and lower body function in older patients at risk of diabetic foot: a randomized controlled trial

INTRODUCTION

To examine the effects of tap dance (TD) on dynamic plantar pressure, static postural stability, ankle range of motion (ROM), and lower extremity functional strength in patients at risk of diabetic foot (DF).

RESEARCH DESIGN AND METHODS

A randomised, single-blinded, two-arm prospective study of 40 patients at risk of DF was conducted. The intervention group (n=20) received 16 weeks of TD training (60 min/session×3 sessions/week). The control group attended four educational workshops (1 hour/session×1 session/month). Plantar pressure, represented by the primary outcomes of peak pressure (PP) and pressure-time integral (PTI) over 10 areas on each foot, was measured using the Footscan platform system. Secondary outcomes comprised static postural stability, ankle ROM and lower extremity functional strength.

RESULTS

Reductions in intervention group PP (right foot: mean differences=4.50~27.1, decrease%=25.6~72.0; left foot: mean differences=-5.90~6.33, decrease%=-22.6~53.2) and PTI at 10 areas of each foot (right foot: mean differences=1.00~12.5, decrease%=10.4~63.6; left foot: mean differences=0.590~25.3, decrease%=21.9~72.6) were observed. Substantial PP and PTI differences were noted at the second through fourth metatarsals, medial heel and lateral heel in the right foot. Substantial PP and PTI differences were detected at metatarsals 1 and 2 and metatarsal 2 in the left foot, respectively. Moderate training effects were found in plantar flexion ROM of both feet, lower extremity functional strength, and length of center-of-pressure trajectory with eyes closed and open (r=0.321-0.376, p<0.05).

CONCLUSIONS

A 16-week TD training program can significantly improve ankle ROM, lower extremity functional strength, and static postural stability. To attain greater improvements in plantar pressure, a longer training period is necessary.

TRIAL REGISTRATION NUMBER

ChiCTR1800014714.

A Novel Low-Cost Wireless Footwear System for Monitoring Diabetic Foot Patients

Diabetic foot is one of the main complications of diabetes with the characteristics of high incidence and difficulty in treatment. Diabetic patients with peripheral neuropathy may develop foot ulcers, and in severe cases amputations are required and some may even die. Plantar pressure can be used to assess the risk of developing diabetic foot, but the existing plantar pressure monitoring methods are not suitable for long-term monitoring in daily life. This study presents a novel low-cost shoe system for daily monitoring of plantar pressure in diabetics. It includes an insole with pressure sensor array, which can dynamically monitor the plantar pressure and display the changes of plantar pressure in real time in the mobile phone to provide early warning for patients with high risk of diabetic foot. As for the sensor, copper and carbon black were adopted as the electrode and conductive filler respectively, enabling a mass production with low price. It was soft and bendable, meeting the performance needs of daily plantar pressure monitoring. All devices were encapsulated in shoes, and the data was transmitted wirelessly through Bluetooth, which did not affect the user's walking. After using random forest for feature selection, five classifiers were used to classify the plantar pressure of healthy people, diabetic patients without peripheral neuropathy, and diabetic patients with peripheral neuropathy collected by this system. The experimental results showed that the accuracy of the random forest classifier was the highest, reaching 94.7%, which indicated that the system could be useful for daily plantar pressure monitoring of diabetic patients.

Footwear and insole design features for offloading the diabetic at risk foot-A systematic review and meta-analyses

The aim of this systematic review was to identify the best footwear and insole design features for offloading the plantar surface of the foot to prevent foot ulceration in people with diabetic peripheral neuropathy. We searched multiple databases for published and unpublished studies reporting offloading footwear and insoles for people with diabetic neuropathy and nonulcerated feet. Primary outcome was foot ulcer incidence; other outcome measures considered were any standardized kinetic or kinematic measure indicating loading or offloading the plantar foot. Fifty-four studies, including randomized controlled studies, cohort studies, case-series, and a case-controlled and cross-sectional study were included. Three meta-analyses were conducted and random-effects modelling found peak plantar pressure reduction of arch profile (37 kPa (MD, -37.5; 95% CI, -72.29 to -3.61; P < .03), metatarsal addition (35.96 kPa (MD, -35.96; 95% CI, -57.33 to -14.60; P < .001) and pressure informed design 75.4 kPa (MD, -75.4 kPa; 95% CI, -127.4 to -23.44 kPa; P < .004).The remaining data were presented in a narrative form due to heterogeneity. This review highlights the difficulty in differentiating the effect of different insole and footwear features in offloading the neuropathic diabetic foot. However, arch profiles, metatarsal additions and apertures are effective in reducing plantar pressure. The use of pressure analysis to enhance the effectiveness of the design of footwear and insoles, particularly through modification, is recommended.

A smart wearable device for monitoring and self-management of diabetic foot: A proof of concept study

BACKGROUND AND OBJECTIVE

Diabetic foot is one of the important complications of diabetes, which is occurred due to the destructive parameters in different anatomical sites of feet. Management and monitoring of these parameters are very important to decrease or prevent foot ulcers. We aimed to develop a smart wearable device to monitor these parameters to prevent diabetic foot.

METHODS

Following literature review and expert panel discussions, we considered pressure, temperature and humidity to develop the system. During these sessions, we also developed the system architecture and determined the required technologies. We also developed a mobile application. Finally, all sensors were evaluated for accurate monitoring of pressure, temperature and humidity. A standard protocol was used to evaluate each of these sensors. To this end, five people (four with diabetes and one healthy person) participated. They did a series of movements including walking, sitting, and standing. We considered the pressure measured by Pedar system as the gold standard. Furthermore, we changed the environment temperature and humidity during several experiments and considered the environment temperature and humidity as gold standard. We compared the measured values by sensors with these gold standards.

RESULTS

The evaluation indicated the accurate performance of pressure, humidity and temperature sensors. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the system to provide alarms based on the pressure measured using Pedar were 100, 50, 92.5, 91.8, and 100 %, respectively. The performance of temperature sensors in smart shoes was confirmed by slight differences compared to thermometers. Relatively equal values of humidity measured by two sensors on the left and right feet and the increased difference with the environment humidity showed the exact humidity measured using these sensors.

CONCLUSION

This smart shoes monitors pressure, humidity, and temperature of patients' feet and sends this data to their smart phone by the Bluetooth module. Furthermore, it controls these parameters; as each of these parameters exceeds the defined threshold, alerts are given to patients for self-management.

Armstrong D. The Potential Role of Sensors, Wearables and Telehealth in the Remote Management of Diabetes-Related Foot Disease

Diabetes-related foot disease (DFD), which includes foot ulcers, infection and gangrene, is a leading cause of the global disability burden. About half of people who develop DFD experience a recurrence within one year. Long-term medical management to reduce the risk of recurrence is therefore important to reduce the global DFD burden. This review describes research assessing the value of sensors, wearables and telehealth in preventing DFD. Sensors and wearables have been developed to monitor foot temperature, plantar pressures, glucose, blood pressure and lipids. The monitoring of these risk factors along with telehealth consultations has promise as a method for remotely managing people who are at risk of DFD. This approach can potentially avoid or reduce the need for face-to-face consultations. Home foot temperature monitoring, continuous glucose monitoring and telehealth consultations are the approaches for which the most highly developed and user-friendly technology has been developed. A number of clinical studies in people at risk of DFD have demonstrated benefits when using one of these remote monitoring methods. Further development and evidence are needed for some of the other approaches, such as home plantar pressure and footwear adherence monitoring. As yet, no composite remote management program incorporating remote monitoring and the management of all the key risk factors for DFD has been developed and implemented. Further research assessing the feasibility and value of combining these remote monitoring approaches as a holistic way of preventing DFD is needed.

Factors influencing Australian podiatrists' behavioural intentions to adopt a smart insole into clinical practice: a mixed methods study

BACKGROUND

Diabetes is the leading cause of lower limb amputation in Australia, costing the Australian health care system an estimated A$1.6 billion annually. Podiatrists are the primary foot health care provider in Australia. Research suggests that health professional attitudes can impact patient utilisation of e-health technologies, such as wearable foot monitoring devices aimed at preventing foot ulceration. The aim of this study was to explore factors that impact the intentions of Australian podiatrists to adopt smart insole foot monitoring technology.

METHODS

A mixed methods explanatory sequential design was undertaken. One hundred and eleven Australian podiatrists completed an online version of the validated Unified Theory of Acceptance and Use of Technology (UTAUT) questionnaire. Multiple regression analysis was used to determine the strongest predictive model of podiatrists' behavioural intention to adopt technology. Additionally, two focus groups were conducted, and thematic analysis was performed to explore podiatrists' perceived barriers and enablers to smart insole adoption.

RESULTS

One hundred and eleven Australian podiatrists completed the online UTAUT questionnaire. The majority of respondents practiced in the private sector (58.6%) and were female (50.5%), with Victoria the most common practice location (39.6%). Significant positive correlations existed between behavioural intention and six psychosocial domains including performance expectancy (r = 0.64, p < 0.001), effort expectancy (r = 0.47, p < 0.001), attitude (r = 0.55, p < 0.001), social influence (r = 0.45, p < 0.001), facilitating conditions (r = 0.36, p < 0.001), and self-efficacy (r = 0.30, p < 0.002). Multiple regression analysis determined that performance expectancy alone was most predictive of behavioural intention to adopt a smart insole into clinical practice (adjusted R2 = 42%, p < 0.001). Qualitative analyses revealed that podiatrists believed that the insole would increase patient knowledge, engagement and self-efficacy. However, concerns were raised about cost, footwear issues and the device's utility with elderly and remote populations.

CONCLUSIONS

Performance expectancy was the most important psychosocial factor predicting the intentions of Australian podiatrists to adopt smart insole foot monitoring technologies. While Australian podiatrists are open to adopting smart insoles into clinical practice, evidence of the device's efficacy is a precursor to adoption. Other perceived barriers to adoption including device cost, compatibility with off-loading, footwear issues and patient age also need to be addressed prior to implementation and clinical adoption.

Facilitators and barriers of using digital technology for the management of diabetic foot ulcers: A qualitative systematic review

The use of digital technology has been shown to be effective in managing chronic conditions. Telemedicine and mobile application are two common applications of digital technology in managing diabetic foot ulcers (DFU). The facilitators and barriers of using it for DFU management are yet to be explored. This is a qualitative systematic review. Five bibliography databases and grey literature sources were searched (2000‐2019). Two reviewers independently screened the citations, extracted the data, assessed the quality of the included studies, and performed thematic synthesis. Three studies on patients and five studies on healthcare practitioners (HCPs) were included. Two studies focused on the use of mobile applications and six on telemedicine. In studies on patients, four analytical themes were generated: the relationships with HCPs; the attitude towards the usage of digital technology; the role of wound image taking; and impact of digital technology on DFU care, encompassing 15 facilitators (eg, enabling community support, improving wound care knowledge) and 12 barriers (eg, lack of technological savviness, difficulty reading on smartphones). Three analytical themes were generated from studies on HCPs: the impact of digital technology on HCPs; the role of digital technology in DFU care; and organisation of DFU care delivery, encompassing 17 facilitators (eg, adequate wound care training, digital technology enables holistic care) and 16 barriers (eg, lack of multidisciplinary approach in caring for DFU, lack of direct contact in care provision). Patients and HCPs reported various barriers and facilitators relating to different aspects of using digital technology in DFU management. Our findings can help inform future research as well as the adoption of digital technology in DFU management.

The role of foot pressure measurement in the prediction and prevention of diabetic foot ulceration-A comprehensive review

The predominant risk factor of diabetic foot ulcers (DFU), peripheral neuropathy, results in loss of protective sensation and is associated with abnormally high plantar pressures. DFU prevention strategies strive to reduce these high plantar pressures. Nevertheless, several constraints should be acknowledged regarding the research supporting the link between plantar pressure and DFUs, which may explain the low prediction ability reported in prospective studies. The majority of studies assess vertical, rather than shear, barefoot plantar pressure in laboratory-based environments, rather than during daily activity. Few studies investigated previous DFU location-specific pressure. Previous studies focus predominantly on walking, although studies monitoring activity suggest that more time is spent on other weight-bearing activities, where a lower "peak" plantar pressure might be applied over a longer duration. Although further research is needed, this may indicate that an expression of cumulative pressure applied over time could be a more relevant parameter than peak pressure. Studies indicated that providing pressure feedback might reduce plantar pressures, with an emerging potential use of smart technology, however, further research is required. Further pressure analyses, across all weight-bearing activities, referring to location-specific pressures are required to improve our understanding of pressures resulting in DFUs and improve effectiveness of interventions.

Leveraging smart technologies to improve the management of diabetic foot ulcers and extend ulcer-free days in remission

The prevalent and long neglected diabetic foot ulcer (DFU) and its related complications rank among the most debilitating and costly sequelae of diabetes. Management of the DFU is multifaceted and requires constant monitoring from patients, caregivers, and healthcare providers. The alarmingly high rates of recurrence of ulcerations in the diabetic foot requires a change in our approach to care and to the vernacular in the medical literature. Our efforts should be directed not only on healing of open wounds, but also on maximizing ulcer-free days for the patient in diabetic foot remission. The increasing development and use of technology within every aspect of our lives represents an opportunity for creative solutions to prevent or better manage this devastating condition. In particular, recent advances in wearable and mobile health technologies appear to show promise in measuring and modulating dangerous foot pressure and inflammation to extend remission and improve the quality of life for these most complex patients. This review article discusses how harnessing wearables and digital technologies may improve the management and optimize prevention of DFUs by identifying high-risk patients for triage and timely intervention, personalizing prescription of offloading, and improving adherence to protective footwear. While still in their infancy, we envisage a future network of skin-worn, jewellery-worn, and implantable sensors that, if allowed to effectively communicate with one another and the patient, could dramatically impact measuring, personalizing, and managing how we and the patients we serve move through our collective world.