Comparison and Clinical Utility of the Portable Pressure Measuring Device for Garment Pressure Measurement on Hypertrophic Scar by Burn Injury During Compression Therapy

The investigators developed a portable pressure measuring device using silicon piezoresistive pressure sensors. As PicoPress® is the most accurate (i.e., lowest variation and error) manometric sensor for pressure measurement, the investigators used it to compare and examine the accuracy of the proposed device regarding in vitro pressure measurements. The purpose of this study was to determine the effectiveness of pressure garment therapy using proposed device with objective data obtained with a randomized within wound comparison. Pressure measurements were acquired through a readout circuit consisting of an analog-to-digital converter, a microprocessor, and a Bluetooth transmission module for wireless data transmission to an external device. The mean pressure values measured by the sensors were compared to those obtained from PicoPress®. This was a double-blinded, randomized, controlled trial of patients with hypertrophic scars. In the pressure monitoring group, garment pressures were monitored using the portable pressure measuring device, and the compression garment was adjusted so that the pressure was maintained at the therapeutic range of 15 - 25 mmHg. In the control group, non-surgical standard treatment of burn scars except for pressure monitoring was performed in the same manner. To evaluate the effect of a pressure monitoring device, the investigators compared the skin test results (thickness, melanin, erythema, TEWL, and skin elasticity levels) between the two groups, from baseline measures immediately before the treatment and measures immediately after 2 months. The participants were made comfortable and acclimatized to room conditions. Room temperature was maintained at 20-25'C and relative humidity at 40-50 %. In the supine position, skin properties were measured. The thickness was measured with a ultrasonic wave equipment (128 BW1 Medison, Korea). Mexameter® (MX18, Courage-Khazaka Electronics GmbH, Germany) was used to measure melanin levels and the severity of erythema. The higher values indicating a darker and redder skin. Transepidermal water loss (TEWL) was measured with a Tewameter® (Courage-Khazaka Electronic GmbH, Germany), which is used for evaluating water evaporation. Elasticity was measured using Cutometer SEM 580® (Courage-Khazaka Electronic GmbH, Cologne, Germany), which applies negative pressure (450 mbar) on the skin. The numeric values (mm) of the skin's distortion is presented as the elasticity. Two seconds of negative pressure of 450 mbar is followed by 2 s of recess, and this consists of a complete cycle. Three measurement cycles were conducted, and the average values were obtained. The parameters consist of the following biomechanical skin properties: distenstibility, elasticity, and viscoelasticity. Distensibility means the length of total displacement from initial postion at maximum negative pressure. Gross elasticity means the ability of the skin to return to its initial position following displacement. Biologic elasticity means the ratio of immediate retraction to total displacement. Viscoelasticity means the ratio of delayed distension of immediate distension. Outcome measurements and data analyses were performed by a trained and blinded outcome assessor who was not involved in the intervention. Possible complications (pain, ecchymosis, pain, skin abrasion, and swelling) were observed.