Elastic Scaling Artificial Anal Sphincter System Based On Wireless Energy Transmission Research

The patient’s normal life are seriously effected by the fecal incontinence. The colostomy are chosen by the seriously patients, while the colostomy produces heavy psychology burdens on patients and reduce the quality of patients’ life. To search the novel methods to replace the colostomy has been a diffuclt but popular research areas. As a results, the artificial anal sphincter(AAS) research has been created and has been proven to be an alternative to colostomy. However there are lots of defects in prosthesis structure, control method, defecation reconstruction, system structure. Therefore, designing the implantable AAS become an important research of biomedical engineering.Supported by the National Natural Science Fund of China(NO.31170968), the elastic scaling artificial anal sphincter system(ES-AASS) has been studied, which base on the achievements of teams’ previous reaearch. And the research work is mainly reflected in the following aspects.1. The vivo animal experiments of artificial anal sphincter system(AASS) are conducted. Two AASS are implanted in the beagles for 7 weeks. During the experiments, the feasibility, validity and safety of AASS has been proved. While three defecats in AASS has also been discovered: Firstly, to implant the AASS needs to conduct the intestinal anastomosis, which cause some bad effects of animals. To design the new prosthesis is one of the key points. Secondly, the “defecation sense” is not stable, the “defecation sense” gathering module needs to be optimized. Finally, during the charging time, the AASS appears unstable work condition. To design the wireless energy transmission(WET) system, which ensure the implantable system working stable during charging, is another key points.2. A novel elastic scaling artificial anal sphincter prosthesis is designed. Compared to the AASS, the ES-AASS has no water pump and the water bag which effectively reduce the complexity, quality of system and the leakage of water bag. And the most importantly, ES-AASS do not need to conduct the intestinal anastomosis.3. The new control modules to satify the elastic scaling prosthesis are optimized. The multi channel of pressure sensors to acquire more accurate “defecation sense” and the multi channel of temperature sensors are designed to ensure the temperature safety of system during charging.4. The more stable wireless receiver modules are designed. The power management unit based on BQ24072 are designed. Which ensure the implanted system work stablely during charging.5. To improve the WET system’s efficiency and stability, the WET system are studied. The bifurcation phenomenon are analysed. To regulate the equivalent load method, the bifurcation phenomenon can be avoided. Optimizing the material and the structure of coils in three aspects: firstly, using the litz lines instead of the copper line, which effectively reduce the skin effect. Secondly, selecting the superior litz line diameter and the bundle of litz line. Thirdly, selecting the optimal ratio between the receiver coil’s inner diamenter and the outer diameter. The optimal tansmission efficiency of WET system is 81.7%.6. The vitro experiments of ES-AASS is carried out. The functions and stability of system are verified. The control pressure threshold is achived. And the feasibility of “defecation sense” is proved.