Precision multi-degree-of-freedom laser therapy system for excision of eschar over burn wound

Early escharotomy in cases of severely burned patients can reduce infection and shorten the course of treatment. From the treatment effect, the quality of escharotomy operation is critical to the postoperative recovery of burn patients. However, the traditional burn wound escharotomy surgery easily causes bleeding as well as other related complications. Applying high-energy laser cutting can effectively reduce bleeding. Moreover, its treatment cycle is short, and it is highly precise, less prone to related complications, and leads to fast postoperative recovery. Considering that the mechatronics of medical equipment can greatly improve the treatment effect and combining the multi-degree-of-freedom motion platform with laser cutting is more convenient, accurate, and effective, this paper focuses on the key technical issues of normal automatic focusing and cutting in complex space wounds. Considering the advantages of multi-degree-of-freedom motion platform, a set of laser escharotomy control system composed of five-degrees-of-freedom motion platform and two-degrees-of-freedom laser optical path control mechanism was proposed. The degree of freedom of the parallel mechanism was analyzed and coordinate system of the whole mechanism was established. Second, inverse kinematic analysis of the laser eschar cutting parallel mechanism was carried out. Last, the position correspondence between the motion platform and the laser light path control mechanism was derived. The system could realize automatic planning of the laser trajectory and complete the automatic laser cutting by combining the derived corresponding position and the 3D scanning result of the complex wound contour. Based on the proposed laser cutting system, an eschar cutting experiment was carried out, and the experimental test results show that the laser escharotomy system can complete the 3D contour scanning and reconstruction of the human hand region well, and it can also automatically plan the laser focus spot motion track and complete the escharotomy.