Accurate tissue flap reconstruction method based on the quadratic surface developability for head and neck soft tissue defects / 生物医学工程学杂志

Soft tissue defects resulting from head and neck tumor resection seriously impact the physical appearance and psychological well-being of patients. The complex curvature of the human head and neck poses a formidable challenge for maxillofacial surgeons to achieve precise aesthetic and functional restoration after surgery. To this end, a normal head and neck volunteer was selected as the subject of investigation. Employing Gaussian curvature analysis, combined with mechanical constraints and principal curvature analysis methods of soft tissue clinical treatment, a precise developable/non-developable area partition map of the head and neck surface was obtained, and a non-developable surface was constructed. Subsequently, a digital design method was proposed for the repair of head and neck soft tissue defects, and an in vitro simulated surgery experiment was conducted. Clinical verification was performed on a patient with tonsil tumor, and the results demonstrated that digital technology-designed flaps improved the accuracy and aesthetic outcome of head and neck soft tissue defect repair surgery. This study validates the feasibility of digital precision repair technology for soft tissue defects after head and neck tumor resection, which effectively assists surgeons in achieving precise flap transplantation reconstruction and improves patients' postoperative satisfaction.

Analysis on therapeutic effect of radiofrequency ablation on discogenic lumbar spinal nerve posterior branch neuralgia after vertebral endoscope surgery / 中国中西医结合急救杂志

Objective To observe the clinical efficacy of radiofrequency ablation for treatment of discogenic lumbar spinal nerve posterior branch neuralgia after vertebral column endoscope operation. Methods Thirty-six patients with discogenic lumbar spinal nerve posterior branch neuralgia after vertebral column endoscope surgery admitted to the Affiliated Hospital of Logistics University of People's Armed Police from December 2011 to December 2017 were enrolled. According to difference in therapeutic methods, they were randomly divided into two groups, 18 cases in each group. The radiofrequency ablation group was treated with X-ray imaging guided lumbar spinal nerve posterior branch radiofrequency thermo-coagulation; the drug group received oral diclofenac sodium conservative treatment, 75 mg twice daily for 3 weeks. Both groups were followed up for 6 months, visual analogue scores (VAS) were used to evaluate the pain before and after treatment, the Oswestry dysfunction index was used to assess the degree of lumbar function recovery, and the surgical complications and adverse drug reactions were observed. Results The VAS scores in the two groups were similar before treatment; after treatment for 1 month, the VAS scores in both groups were significantly lower than those before treatment (radiofrequency ablation group: 1.83±0.71 vs. 5.67±0.77; drug group: 2.22±0.43 vs. 5.28±0.67, both P < 0.05); after treatment for 3 months and 6 months, the VAS scores were increased gradually, however, the scores of radiofrequency ablation group were significantly lower than those in the drug group (3 months was 2.00±0.59 vs. 3.39±0.70, 6 months was 2.17±0.51 vs. 3.61±0.50, both P < 0.05), moreover, the excellent and good rates of postoperative pain efficacy and of Oswestry dysfunction index improvement in the radiofrequency ablation group were significantly higher than those in the drug group [excellent and good rates of postoperative pain efficacy: 94.44% (17/18) vs. 22.22% (4/18), excellent and good rates of Oswestry dysfunction index improvement: 77.78% (14/18) vs. 44.44% (8/18), both P < 0.05]. There were no complications of infection and spinal nerve anterior branch injury in the radiofrequency ablation group, and 6 patients in the drug group presented mild gastric discomfort, which was relieved after symptomatic treatment. Conclusion The radiofrequency ablation is an effective method for treatment of discogenic lumbar neuralgia after vertebral column operation, compared with the conservative therapy, the ablation is more effective to relieve pain for a long time, promote the recovery of neural function, and the operation is safe with very few adverse reactions.

Simulation prediction of bone defect repair using biodegradable scaffold based on finite element method / 生物医学工程学杂志

Aiming at the problem of scaffold degradation in bone tissue engineering, we studied the feasibility that controlls bone defect repair effect with the inhomogeneous structure of scaffold. The prediction model of bone defect repair which contains governing equations for bone formation and scaffold degradation was constructed on the basis of analyzing the process and main influence factors of bone repair in bone tissue engineering. The process of bone defect repair and bone structure after repairing can be predicted by combining the model with finite element method (FEM). Bone defect repair effects with homogenous and inhomogeneous scaffold were simulated respectively by using the above method. The simulation results illustrated that repair effect could be impacted by scaffold structure obviously and it can also be controlled via the inhomogeneous structure of scaffold with some feasibility.

Examining method and equipment of ultrasonic knife frequency / 医疗卫生装备

Objectives To detect ultrasonic knife frequency and correct the result.Methods Oscillography analysis law was adopted to determine the frequency.Results Oscillography analysis law was practical for the determination of ultrasonic knife frequency.Conclusion This paper realizes the quantitative detection of ultrasonic knife frequency without related national standard and industrial standard.