There are currently 3 established techniques employed routinely to determine the risk of foot ulceration in the patient with diabetes mellitus. These are the assessment of circulation, neuropathy, and foot pressure. These assessments are widely used clinically as well as in the research domain with an aim to prevent the onset of foot ulceration. Routine neuropathic evaluation includes the assessment of sensory loss in the plantar skin of the foot using both the Semmes Weinstein monofilament and the biothesiometer. Thermological measurements of the foot to assess responses to thermal stimuli and cutaneous thermal discrimination threshold are relatively uncommon. Indeed, there remains uncertainty regarding the importance of thermal changes in the development of foot ulcers. Applications of thermography and thermometry in lower extremity wounds, vascular complications, and neuropathic complications have progressed as a result of improved imaging software and transducer technology. However, the uncertainty associated with the specific thermal modality, the costs, and processing times render its adaptation to the clinic. Therefore, wider adoption of thermological measurements has been limited. This article reviews thermal measurement techniques specific to diabetic foot such as electrical contact thermometry, cutaneous thermal discrimination thresholds, infrared thermography, and liquid crystal thermography.

The aim of this paper is to present a comparison of video- and sensor-based studies of swimming performance. The video-based approach is reviewed and contrasted to the newer sensor-based technology, specifically accelerometers based upon Micro-Electro-Mechanical Systems (MEMS) technology. Results from previously published swim performance studies using both the video and sensor technologies are summarised and evaluated against the conventional theory that upper arm movements are of primary interest when quantifying free-style technique. The authors conclude that multiple sensor-based measurements of swimmers' acceleration profiles have the potential to offer significant advances in coaching technique over the traditional video based approach.

Recent advances in the development of transducers for the measurement of vertical and shear forces acting on the plantar surface of the foot are reviewed. Barefoot and in-shoe discrete and matrix transducers are reviewed in terms of structure, operation, performance and limitations. Examples of capacitive, piezo-electric, optical, conductive and resistive types of transducer are presented. Where available, the current clinical status is specified.

There are, currently, 3 established clinical techniques routinely employed to determine the risk of ulceration in the diabetic foot. These are assessment of the circulation, the nervous control of sensation, and foot sensitivity to loading. Macrovascular measurements are used to assess sufficiency of the arterial supply to the foot. Evaluation of somatic neuropathy provides an indication of loss of plantar sensation. Skin pressure measurements indicate abnormalities in plantar loading. This combined approach is effective in allowing preventative measures to be applied prior to the onset of ulceration. In contrast, clinical measurement of microvascular function in the diabetic foot is uncommon. Indeed, there remains uncertainty regarding the importance of micro-vascular complications in the development of foot ulcers. This is in part due to the difficulty of making in vivo measurements of microvascular function. This article evaluates 3 noninvasive measurement techniques for routine microvascular assessment of the diabetic foot: transcutaneous oxygen tension, laser Doppler flowmetry, and near-infrared spectroscopy. These techniques can be used to obtain useful parameters of microvascular function including surface oxygen,blood flow, intracellular oxygenation, and cellular respiration. In principle, such measurements can be related to underlying pathophysiology, for example, microangiopathy or autonomic neuropathy. This article considers how these general techniques can be adapted to support routine clinical measurement of microvascular function, particularly in the neuropathic diabetic foot.

An in-shoe laser Doppler sensor for assessing plantar blood flow in the diabetic foot. Jonathan Edwin CobbPlantar ulceration is a complication of the diabetic foot prevalent in adults with type 11 diabetes mellitus. Although neuropathy, microvascular disease and biornechanical factors are all implicated, the mechanism by which the tissue becomes pre-disposed to damage remains unclear. Recent theories suggest that the nutritional supply to the tissue is compromised, either by increased flow through the arteriovenous anastomoses ('capillary steal' theory) or through changes in the micro vascu I ature (haemodynamic hypothesis). Clinical data to support these ideas has been limited to assessment of the unclad foot under rest conditions. A limitation of previous studies has been the exclusion of static and dynamic tissue loading, despite extensive evidence that these biornechanical factors are essential in the development of plantar ulceration. The present study has overcome these problems by allowing assessment of plantar blood flow, in-shoe, during standing and walking.The system comprises a laser Doppler blood flux sensor operating at 780nm, load sensor, measurement shoe, instrumentation, and analysis software. In-vitro calibration was performed using standard techniques. An in-vivo study of a small group of diabetic subjects indicated differences in the blood flux response between diabetic neuropaths, diabetics with vascular complications and a control group. For example, following a loading period of 120s, relative increases in response from rest to peak were: Control (150% to 259%), Vascular (-70% to 242%), Neuropathic (109%-174%) and recovery times to 50% of the peak response were: Control (33s to 45s), Vascular (43s to >120s), Neuropathic (>120s). Dynamic re-perfusion rates (arbitrary units per millisecond) obtained for the swing phase of gait were: Control (6.1 a. u/ms to 7.9 a. u/ms), Vascular (4 a. u/ms to 6.2 a. u/ms), Neuropathic (2.3 a. u/ms to 4.5 a. u/ms).

Functional Electrical Stimulation (FES) is a technique that uses electricity to activate the nerves of a muscle that is paralysed due to hemiplegia, multiple sclerosis, Parkinson's disease or spinal cord injury (SCI). FES has been widely used to restore upper limb functions in people with hemiplegia and C5-C7 tetraplegia and has improved their ability to perform their activities of daily living (ADL). At the time of writing, a detailed literature review of the existing upper limb FES devices and their man-machine interfaces (MMI) showed that only the NESS H200 was commercially available. However, the rigid arm splint doesn't fit everyone and prevents the use of a tenodesis grip. Hence, a robust and versatile upper limb FES device that can be used by a wider group of people is required.

The aim of this article was to investigate the effectiveness of testing cold immersion recovery responses in the diabetic foot with neuropathy using a contact thermography system based on thermochromic liquid crystals. A total of 81 subjects with no history of diabetic foot ulceration were assigned to neuropathy, non neuropathy and healthy groups. Each group received prior verbal and written description of the test objectives and subsequently underwent a comprehensive foot care examination. The room temperature and humidity were consistently maintained at 24 degrees C and less than 50%, respectively, with air conditioning. The right foot for each subject was located on the measurement platform after cold immersion in water at 18-20 degrees C. Whole-field thermal images of the plantar foot were recorded for 10 minutes. Patients with diabetes with neuropathy show the highest 'delta temperature', that is difference between the temperature after 10-minute recovery period and baseline temperature measured independently at all the three sites tested, that is first metatarsal head (MTH), second MTH and heel. This clinical study showed for the first time the evidence of poor recovery times for the diabetic foot with neuropathy when assessing the foot under load. A temperature deficit (because of poor recovery to baseline temperature) suggests degeneration of thermoreceptors, leading to diminished hypothalamus-mediated activity in the diabetic neuropathic group.

Liquid crystal thermography (LCT) is a common surface temperature measurement technique. Typically, the colour response is calibrated against temperature by building an analytical relation between the temperature and the hue of the colour. A suitable polynomial fit is then used to describe this relation after removing the discontinuity in the hue. The variability of hue at each calibration point determines the temperature resolution. However, this technique does not take into consideration the variability in R, G and B intensities used to determine the hue, leading to uncertainty in the measured temperature. This paper describes a novel technique using neural networks to calibrate thermochromic liquid crystal (TLC) material and compensate for high variability in RGB intensities along with other sources of noise in the data. A TLC-based temperature measurement system and calibration results are presented. In our measurements, the lighting intensity (8-bit mean intensity of black surface ± standard deviation) is changed from a minimum of 16.65 ± 2.30 to a maximum of 31.41 ± 3.85. The neural networks were trained on the steady-state TLC calibration system. The results indicate that the neural networks can cope with the variation in lighting by merging the shifted hue curves into a single curve determined by the regression analysis of the test data. Performance characteristics studied on various network configurations relevant to the analysis are described. This approach may be useful in developing liquid crystal thermography for various biomedical applications.