A wireless power transmission method based on electromagnetic coupling was proposed for gastrointestinal microsystems. We analyzed the coupling coefficient, taking coils' misalignments into account by calculating mutual inductance. A power transmission model was built up. And based on this model, the electric parameters of maximizing the received power were deducted under weakly coupling condition. From the transmitting efficiency formula, we found two ways to enhance the efficiency. The transmission power was more than 200mW in our experiments when the receiving coil was located at the center of transmitting coil. This validated the method feasibility.
Capsule Endoscopes ; Capsule Endoscopy ; methods ; Electric Power Supplies ; Electromagnetic Fields ; Equipment Design ; Gastrointestinal Diseases ; diagnosis ; Humans ; Miniaturization

OBJECTIVE To evaluate the post-marketing safety of Compound porcine cerebroside and ganglioside injection in patients with ischemic stroke. METHODS A drug-induced， prospective， non-controlled clinical study design was conducted. Using the patients with ischemic stroke who received Compound porcine cerebroside and ganglioside injection at least once in 46 secondary class A and above medical institutions across the country from April 2020 to May 2021 as the monitoring objects， and their basic data， medication information and the occurrence of adverse drug reactions were analyzed. RESULTS Among 13 514 patients with ischemic stroke， the incidence of adverse events was 10.01%， and the incidence of adverse reactions related to Compound porcine cerebroside and ganglioside injection was 0.33%. Drug-related adverse drug reactions were mild or moderate， concentrated in the gastrointestinal system （18 cases）， skin and subcutaneous tissue （10 cases）， nervous system （7 cases） and other systems/organs， mainly including constipation， abdominal pain， diarrhea， rash， pruritus， dizziness and other symptoms. Most of the patients （91.03%） recovered or improved after treatment， and 2 patients died. Among the 45 patients with adverse drug reactions， 84.44% were cured or improved after drug withdrawal or symptomatic treatment， and 15.56% had no significant change. The incidence of adverse drug reactions in tertiary hospitals was significantly higher than that in secondary hospitals， and the incidence of adverse drug reactions in patients with allergic history was significantly higher than that in patients without allergic history （P＜0.05）. Irrational drug use was found in 2.76% of patients， and the incidence of adverse drug reactions（2.95%） was significantly higher than that in patients without irrational drug use（0.26%，P＜0.05）. CONCLUSIONS The adverse drug reaction symptoms of ischemic stroke patients treated with Compound porcine cerebroside and ganglioside injection are relatively common， the incidence rate is generally low， and it is related to the patients’ physique and whether the drug use is standardized.