Preliminary Results of Lidar Technology in Hand Surgery

Abstract

Introduction: LiDAR is a method for measuring the distance by illuminating the target with laser light and measuring the reflection with a sensor. Differences in laser return times and wavelengths can then be used to make digital 3D representations of the target. The authors used LIDAR technology to scan patient´s hands before surgery to determine baseline values for the range of motion of small hand joints. Materials and Methods: The study involved 10 patients (8 men and 2 women) between the ages of 51-81 years with a median age of 63 years. None of the patients had a thumb or index finger contracture. The most often contracted was IV. finger - in 7 cases, V. finger in 6 cases and III. finger in 1 case. The evaluation was performed with the assistance of experienced physiotherapists, who measured the extent of contracture of individual fingers using a goniometer (accuracy calibrated at 5 °) before surgery. Results: Evaluation was finished on 8 fingers (7 patients) out of a total of 14 fingers (10 patients). The differences between the results using the goniometer and the LiDAR technology are as follows. Difference in MCP: 2°-24° with median of 9°, difference in PIP: 4°-23 ° with median of 6.5°. Different values in the results might be due to inexperience in taking LiDAR scans or incorrect evaluation of the angles on the individual joints of the fingers. Conclusion: A pilot study confirmed the applicability of LiDAR technology for measuring trigonometric functions of small hand joints. In our opinion the biggest disadvantage of LiDAR technology is time delay in obtaining results compared to goniometer measurements. The biggest advantage is the accuracy of measurement to individual degrees. If the evaluation software can be implemented in a scanning application, this will lead to significant increase in speed of results acquisitions.