Numerical simulation is one of the most significant methods to predict the temperature distribution in high-intensity focused ultrasound (HIFU) therapy. In this study, the adopted numerical simulation was used based on a transcranial ultrasound therapy model taking a human skull as a reference. The approximation of the Westervelt formula and the Pennes bio-heat conduction equation were applied to the simulation of the transcranial temperature distribution. According to the temperature distribution and the Time Reversal theory, the position of the treatable focal region was corrected and the hot spot existing in the skull was eliminated. Furthermore, the influence of the exposure time, input power and the distance between transducer and skull on the temperature distribution was analyzed. The results showed that the position of the focal region could be corrected and the hot spot was eliminated using the Time Reversal theory without affecting the focus. The focal region above 60 degrees C could be formed at the superficial tis sue located from the skull of 20 mm using the hot spot elimination method and the volume of the focal region increases with the exposure time and the input power in a nonlinear form. When the same volume of the focal region was obtained, the more power was inputted, the less the exposure time was needed. Moreover, the volume of the focal region was influenced by the distance between the transducer and the skull.
Computer Simulation ; High-Intensity Focused Ultrasound Ablation ; Hot Temperature ; Humans ; Neoplasms ; therapy ; Skull

The clinical practice guidelines for prevention and treatment of postoperative gastrointestinal disorder with Integrated Traditional Chinese and Western Medicine (2023) issued by the Anaesthesia Committee and Perioperative Medicine Committee of the Chinese Society of Integrative Medicine is the first evidence-based guideline for postoperative gastrointestinal disorder in China. It covers the definition, aetiology and pathogenesis, diagnosis and treatment of postoperative gastrointestinal disorder. Compared with previous expert consensus, this guideline has advantages in terms of scientific and rigorous methodology and is quite representative. Interpreting this guideline can help strengthen clinicians′ understanding of postoperative gastrointestinal disorder and enhance clinical practitioners′ understanding of the methodology of this guideline, thus enabling a better integration of recommendations and evidence for clinical practice and hastening the implementation of the guidelines. It also accelerates the dissemination of the methodological development of guidelines in China, helps clinicians understand the connotation and value of the guidelines, and provides methodological guidance and references for formulating clinical practice guidelines based on the current situation in China and involving other clinical disciplines.

Objective To evaluate the efficacy of preoperative electroacupuncture intervention in promoting postoperative gastrointestinal functional recovery by meta-analysis.Methods The databases of PubMed,Cochrane Library,Web of Science,Embase,CBM,CNKI,VIP,and WanFang were searched systematically.The search period ranged from the inception of the databases to March 2024.Two researchers screened the literature independently,extracted the data,used Cochrane Risk of Bias tools to evaluate the quality of the inclusion study,and used RevMan 5.3 software for meta-analysis.Results Twelve RCTs were included,with 773 patients.There were 421 patients in the preoperative electroacupuncture group and 352 patients in the control group.The results of the meta-analysis showed that,time to first flatus(SMD=-0.56,95%CI-0.84 to-0.28,P＜0.001),time to first defecation(MD=-6.40 hours,95%CI-9.27 to-3.53,P＜0.001),time to bowel sound recovery(MD=-8.45 hours,95%CI-10.37 to-6.52,P＜0.001),time to first oral feeding(MD=-16.88 hours,95%CI-23.92 to-9.83,P＜0.001),the incidence of PONV(RR=0.75,95%CI 0.57 to 0.98,P=0.04)and length of hospital stay(MD=-0.78 d,95%CI-1.38 to-0.19,P=0.010)were significantly lower than the control group.Conclusion Electroacupuncture intervention before operation can effectively promote the recovery of post-operative exhaust,defecation,and bowel sound,shorten the time of fasting and drinking,reduce the inci-dence of PONV,shorten the length of hospital stay,and has good clinical value in promoting the recovery of postoperative gastrointestinal function.