Using clinical thermography as diagnostic complementary procedure for Hand Arm Vibration Syndrome

Introduction: Hand-Arm Vibration Syndrome is an occupational condition that affects people exposed to vibrating tools in the workplace and needs an accurate quantitative and objective diagnostic test to aid clinicians in the judgment of the degree of injury and correspondent treatment. An objective assessing method is needed to provide a permanent evidence record of the degree of injury. Methods: Medical thermography was used with a developed objective mechanic provocation test involving vertical vibration exposure of hands, for 2 minutes at 31.5Hz of vibration frequency and 36 mm/s2 of vibration magnitude, which was followed by a vascular provocation challenge of the hand for a period of 1 minute at 20°C. Images were taken during the whole procedure. In order to assess the peripheral temperature changes of the hand a computational model was developed and the images standardised and analised. Results: It was possible to discriminate between degrees of injury groups (p<0.05) but not individuals. It was possible to identify through medical thermography the affected fingers and its temperature changes quantified assessing objectively the stage of the injury. Conclusion: The proposed method is objective and repeatable, can provide information of the evolutionary stage of the condition. Medical thermal imaging can be used as diagnostic tool to provide evidence of occupational condition affecting upper limbs in support to medical history in medico-legal liabilities.