RESUMEN
This study investigated the force-frequency characteristics of quartz wafers inside a cantilever beam frame. Firstly, the force-frequency coefficient formula of quartz wafers with fixed ends under axial force was analyzed. Firstly, the formula for the force-frequency coefficient of quartz wafers with fixed ends under axial force was analyzed. A force-frequency coefficient formula suitable for cantilever beam structures was derived by considering the changes in surface stress and stiffness of quartz wafers with fixed ends and one end under force on the other. Subsequently, the formula's accuracy was verified by experiments, and the accuracy was more than 92%. In addition, strain simulation analysis was performed on three different shapes of quartz wafers, and experimental verification was carried out on two of them. The results revealed that trapezoidal quartz wafers and cantilever beam structures exhibited superior stress distribution to rectangular chips. Furthermore, by positioning electrodes at various locations on the surface of the quartz chip, it was observed that, as the electrodes moved closer to the fixed end, the force-frequency coefficient of the rectangular quartz chip increased, along with an increase in chip strain under the cantilever structure. In summary, this study provides a new approach for designing cantilever quartz resonator sensors in the future.
RESUMEN
OBJECTIVE: To discuss the feasibility of water infusion colonoscopy and its difference with traditional air insufflation colonoscopy in application value. METHODS: A prospective randomized controlled clinical study was designed to include 200 patients who underwent sedation-free diagnostic colonoscopy. Among them, 100 patients were treated with water infusion colonoscopy (observation group) and 100 patients were treated with air insufflation colonoscopy (control group). All operations were performed independently by the same experienced physician. The differences in colonoscopy related values, colon adenoma detection rate, and follow-up findings between the patients of two groups were compared. RESULTS: There was no significant difference in the Boston bowel preparation scale (BBPS) score of the left hemicolon, transverse colon, right hemicolon, total BBPS scores, and bubble amount between the two groups (P>0.05). In the observation group, the scope-forward time, the time to reach the ileocecal junction, and the total operation time were significantly longer than that of the control group (P<0.01). The proportion of patients in whom the ileocecal junction was successfully reached was significantly higher in the observation group. The intraoperative abdominal pain visual analog scale (VAS) score, abdominal distension VAS score, the proportion of postural change, and the proportion of abdominal compression were all significantly lower in the observation group (P<0.05). There were no significant differences in the endoscope hardness adjustment rate, the scope withdrawal time, total detection rate of adenomas, and the size or location of colon adenomatous lesions between the two groups (P>0.05). Compared with control group, the incidence of abdominal pain and VAS scores were significantly lower in the observation group (P<0.05), and the willingness of patients to perform colonoscopy again was significantly higher (P<0.01). CONCLUSION: Patients' tolerance and examination satisfaction are significantly better when using water infusion colonoscopy compared with traditional air insufflation colonoscopy, but the operation times are longer.
