Detection of inflammation from finger temperature profile in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory tissue disease that leads to cartilage, bone, and periarticular tissue damage. This study aimed to investigate whether the use of infrared thermography and measurement of temperature profiles along the hand fingers could detect the inflammation and improve the diagnostic accuracy of the cold provocation test (0 °C for 5 s) and rewarming test (23 °C for180 s) in RA patients. Thirty RA patients (mean age = 49.5 years, standard deviation = 13.0 years) and 22 controls (mean age = 49.8 years, standard deviation = 7.5 years) were studied. Outcomes were the minimal and maximal: baseline temperature (T1), the temperature post-cooling (T2), the temperature post-rewarming (T3), and the Tmax-Tmin along the axis of each finger. The statistical significance was observed for the thumb, index finger, middle finger, and ring finger post-cooling and post-rewarming. Receiver operating characteristics (ROC) analysis to distinguish between the two groups revealed that for the thumb, index finger, middle finger, and ring finger, the area under the ROC curve was statistically significantly (p < 0.05) post-cooling. The cold provocation test used in this study discriminates between RA patients and controls and detects an inflammation in RA patients by the measurement of temperature profiles along the fingers using an infrared camera.

Interactions of mild hypothermia and hypoxia on finger vasoreactivity to local cold stress

We examined the interactive effects of mild hypothermia and hypoxia on finger vasoreactivity to local cold stress. Eight male lowlanders performed, in a counterbalanced order, a normoxic and a hypoxic (partial pressure of oxygen: ~12 kPa) hand cold provocation (consisting of a 30-min immersion in 8°C water), while immersed to the chest either in 21°C [cold trials; 0.5°C fall in rectal temperature (Trec) from individual preimmersion values], or in 35.5°C water, or while exposed to 27°C air. The duration of the trials was kept constant in each breathing condition. Physiological (Trec, skin temperature, cutaneous vascular conductance, oxygen uptake) and perceptual (thermal sensation and comfort, local pain, affective valence) reactions were monitored continually. Hypoxia accelerated the drop in Trec by ~14 min ( P = 0.06, d = 0.67). In the air-exposure trials, hypoxia did not alter finger perfusion during the local cooling, whereas it impaired the finger rewarming response following the cooling ( P < 0.01). During the 35.5°C immersion, the finger vasomotor tone was enhanced, especially in hypoxia ( P = 0.01). Mild hypothermia aggravated finger vasoconstriction instigated by local cooling ( P < 0.01), but the response did not differ between the two breathing conditions ( P > 0.05). Hypoxia tended to attenuate the sensation of coldness ( P = 0.10, r = 0.40) and thermal discomfort ( P = 0.09, r = 0.46) in the immersed hand. Both in normoxia and hypoxia, the whole body thermal state dictates the cutaneous vasomotor reactivity to localized cold stimulus.

Evaluation of Perfusion and Thermal Parameters of Skin Tissue Using Cold Provocation and Thermographic Measurements

Measurement of the perfusion coefficient and thermal parameters of skin tissue using dynamic thermography is presented in this paper. A novel approach based on cold provocation and thermal modelling of skin tissue is presented. The measurement was performed on a person’s forearm using a special cooling device equipped with the Peltier module. The proposed method first cools the skin, and then measures the changes of its temperature matching the measurement results with a heat transfer model to estimate the skin perfusion and other thermal parameters. In order to assess correctness of the proposed approach, the uncertainty analysis was performed.

Raynaud's Phenomenon in a Slap Bass Player: A Case Report

OBJECTIVE: Secondary Raynaud’s phenomenon is a frequent condition related to occupational exposure to local vibration but has not been described in musicians. This study aims to describe cold-induced blanching of the right second and (in particular) third digits in a 67-year-old double bass player following decades of cumulative repetitive blunt trauma to the fingers from slapping the strings. METHODS: A physical examination was undertaken and systolic blood pressure measured before and after cold provocation. RESULTS: At 10ÅãC the brachial systolic blood pressure was 156 mm Hg while blood pressure was immeasurable at the finger level, corresponding to a finger/brachial index of 0% of the second and third fingers. CONCLUSION: This is the first reported case of objectively verified, playing-related Raynaud’s phenomenon in a musician.