A portable in-shoe measurement system to acquire dense continuous foot temperature maps
Technical lead: Dr Owen Falzon
, Centre for Biomedical Cybernetics
Clinical lead: Dr Stephen Mizzi
, Deptartment of Podiatry, Faculty of Health Sciences
Technical development: Inġ Josef Grech, Centre for Biomedical Cybernetics
Knowledge Transfer Executive: Inġ. Michelle Cortis, Knowledge Transfer Office
Externally funded: MCST-CVP R&I-2018-016-V (2018) EUR 17,000
Foot temperature is an important measure to consider when assessing the perfusion and general health condition of the healthy foot and more importantly the foot in disease, namely diabetes [1, 2]. While thermography can nowadays allow for the acquisition of a dense temperature map from bare feet, the technology cannot provide in-shoe temperature readings which are particularly of interest since these provide a more accurate picture of foot temperature evolution during normal walking or exercise conditions.
While a number of in-shoe temperature measurement systems have been developed, these are typically limited to a few localised temperature sensors within the shoe  and no setups that provide a dense in-shoe temperature map have been developed.
We are developing a portable in-shoe monitoring system that can be used to acquire dense temperature maps from the foot during normal daily activities and over extended periods of time. The acquired data can in turn be utilised to more reliably assess the suitability of footwear, therapeutic footwear in diabetes, foot regions prone to ulceration, or other abnormal conditions.
While some studies have proposed in-shoe temperature measurement systems that provide readings from a few locations on the foot, these systems do not provide sufficient information on the temperature dynamics and variations across the entire foot during ambulation [3, 4]. Therefore, up to now there are no studies or products that consider long-term in-shoe temperature variations, neither in healthy individuals nor in individuals living with diabetes mellitus or other conditions that may affect the lower limb perfusion. Therefore, acquiring this information reliably during ambulation can allow for enhanced patient monitoring with a minimal intrusion, in order to provide a better understanding of the risk associated with these conditions which in turn can lead to improved preventive and treatment plans.
In this project the aim is to develop a portable dense temperature sensing array that can provide reliable continuous measurements of in-shoe foot temperature. This in-shoe system will also be designed to allow for long-term temperature recording allowing for seamless monitoring of temperature during a patient’s daily activities.
In addition to the hardware components of the proposed in-shoe temperature monitoring system, a software application that provides patients and clinicians with easy access, automated analysis and visualisation of the recorded data will be provided thereby allowing for improved assessment, prevention and treatment plans for patients.
 Armstrong, D. G., Holtz-Neiderer, K., Wendel, C., Mohler, M. J., Kimbriel, H. R., & Lavery, L. A. (2007). 'Skin temperature monitoring reduces the risk for diabetic foot ulceration in high-risk patients.' The American Journal of Medicine, 120(12), 1042-1046.
 Gatt, A., Formosa, C., Cassar, K., Camilleri, K. P., De Raffaele, C., Mizzi, A., ... & Chockalingam, N. (2015). 'Thermographic patterns of the upper and lower limbs: baseline data.' International Journal of Vascular Medicine, 2015.
 Morley, R. E., Richter, E. J., Klaesner, J. W., Maluf, K. S., & Mueller, M. J. (2001). 'In-shoe multisensory data acquisition system.', IEEE Transactions on Biomedical Engineering, 48(7), 815-820.
 Maluf, K. S., Morley, R. E., Richter, E. J., Klaesner, J. W., & Mueller, M. J. (2001). 'Monitoring in-shoe plantar pressures, temperature, and humidity: reliability and validity of measures from a portable device.' Archives of physical medicine and rehabilitation, 82(8), 1119-1127.