| Achalasia is a rare primary esophageal neuromuscular disorder termed as the absence of peristalsis.Clinical symptoms include slowly progressive dysphagia for solid and liquid,regurgitation of bland undigested food,chest pain and so on.As a common symptom of achalasia,Gastroesophageal reflux disease(GERD)is the most common disease of functional gastrointestinal disorder.Clinical symptoms include heart burn,acid regurgitation and so on.These two diseases bring a lot inconvenience to the daily life of patients.The treatments of achalasia and GERD aim at changing the pressure of the lower esophageal sphincter(LES),and can’t improve the esophageal peristalsis.So the long-term curative effect of the surgical intervention is not ideal.Research on functional electrical stimulation(FES)has been introduced in the treatments of GERD and functional gastrointestinal disorder.Multi-points sequential FES has been proved effective in provoking sequential movement of intestinal smooth muscle,and FES on LES has been proved effective in GERD.So some researcher proposed to apply FES in the treatment of achalasia and GERD.Thus,aiming at realizing the application of FES in the treatment of achalasia and GERD,this study designed a FES system based on swallow perception and GERD monitoring technology.The main contribution of this paper summarized below.1.Completed the designation of the system structure of implantable esophageal electrical stimulation system,and completed the division of functional modules.2.Completed the designation of GERD monitoring module.Designed an impedance analysis module based on AD5933 chip,monitoring the impedance of esophagus,realizing the recognition of GERD symptom and controlling the implantable device generating a certain stimulation.3.Completed the designation of the acquisition of swallowing signal module.Applied the bend sensor and analog circuit to acquire the swallowing signal,controlling the implantable device generating a certain stimulation.4.Applied CC2530 chip as the main controller of wireless communication module,realizing the cooperation of outside controller and inside stimulator,and the adjustment of the parameters of stimulation.Meanwhile,Man-machine interaction was designed based on LCD and keys to bring convenience to users.5.High degree integrated and low power chip MSP430 was adopted as the core controller.By-phase voltage controlled constant-current sources and stimulation output circuit were adopted in the system to generate the by-phase constant current stimulation which has two modes and adjustable parameters.6.Built the esophagus pacing experiment system and completed the stimulation parameters test,wireless communication test,swallowing signal acquisition experiment and GERD monitoring experiments to verify the feasibility of the system. |
