The ideal treatment of localized cancer should directly cause an irreversible and complete death of tumor cells without damage to surrounding normal tissue. High intensity focused ultrasound (HIFU) is such a potential treatment, which induces a complete coagulative necrosis of a tumor at depth through the intact skin. The idea that using an extracorporeal source of therapeutic ultrasound was introduced more than 50 years ago [J. Gen. Physiol. 26 (1942) 179]. However, up to now, most of the studies on HIFU have been dealing with animal experiments because this extracorporeal technique is very complicated in clinical applications. The purpose of this study is to introduce Chinese clinical experience of using extracorporeal HIFU for the treatment of patients with various kinds of solid tumor. From December 1997 to October 2001, a total of 1038 patients with solid tumors underwent HIFU ablation in China. Among them, 313 patients were treated at the Chongqing University of Medical Sciences, China. Pathological examination showed that the target region presented clear evidence of cellular destruction. Small blood vessels less than 2 mm in diameter were severely damaged. Follow-up diagnostic imaging revealed that there was no, or reduced, blood supply, and no uptake of radioisotope in the treated tumor after HIFU, both indicating a positive therapeutic response and an absence of viable tumor. Imaging at 6-12 months showed obvious regression of the lesion. Four-year follow-up data were significantly observed in patients with hepatocellular carcinoma, osteosarcoma, and breast cancer. An extremely low major complication rate was noted. It is concluded that HIFU ablation is a safe, effective, and feasible modality for the ablation of carcinomas.

To explore the impact of high-intensity focused ultrasound (HIFU) ablation of uterine fibroids in nulliparous women on subsequent pregnancy and delivery. A retrospective analysis was conducted of nulliparous women who received HIFU treatment at Chongqing Medical University, Chongqing,China, from January 1, 2010, to January 1, 2015. A total of 189 cases were enrolled, the median follow-up time was three years. Among them,there were 131 cases pregnancy with a total of 133 times,the pregnancy rate was 69.3% (131/189),and the spontaneous conception rate was 95.4% (125/131). Of 131 pregnant women, 19 were on-going pregnancy, terminated pregnancy 114 times,which include 93 times successfully delivery with a 76.3% (87/114) full-term birth rate,and the cesarean section rate was 72.0% (67/93). Of 94 newborns,the average birth weight was (3.3 ± 0.4)kg (range:1.5–4.8 kg), and a pair of them were identical twins. The incidence of complications during pregnancy and delivery were 10.8% (10/93) and 7.5% (7/93),respectively,except one woman failed on-going pregnancy and one woman suffered hysterectomy due to the complications,others all successful pregnant and delivered. Multiple-factor regression analysis found that age and infertility history were the important factors that may affect pregnancy after HIFU (P < 0.01). Nulliparous women who undergo HIFU treatment for uterine fibroids can subsequently have successful pregnancy and delivery safely.

FCD-based traffic navigation system is getting more and more attention from countries all over the world. Shortest path algorithm is one of the key techniques of a traffic navigation system. Since classical Dijkstra algorithm and heuristic A* algorithm cannot support some constrained conditions in practice, and existing algorithms supporting constraints require the road network to be modified ahead and have low efficiency. The paper studies the model of road network, and analyzes two types of constraints, one-way street and intersection turning prohibitions, then proposes the constrained A* algorithm and gives the Heuristic function. Finally, the paper tests and analyzes the algorithm, and evaluation performance of the prototype system which employs it. The result shows that the algorithm’s efficiency is fairly good.