Oncological safety of use of ultrasonic activated shears in gastric cancer surgery: Long-term results of randomized controlled trial

Objective： Ultrasonically activated shears （UAS） have been applied in open gastric surgeries with no or little evidence. It was previously reported about the surgical outcome and effectiveness of UAS based on a randomized controlled trial of 256 patients with gastric cancer. We aimed to clarify the long-term oncological safety of the use of UAS in the aspect of overall survival and recurrence.Methods： Gastric cancer patients who underwent gastrectomy with D2 lymph node dissection were enrolled and randomly assigned to either the conventional surgery group （n=125） or the UAS group （n=128）. Survival, recurrence and long-term postoperative complications were compared between the two groups. The median follow-up period was 56 months.Results： Gastric cancer-related death was higher in patients of the UAS group compared with the conventional group （P=0.019）. Overall survival rates stratified by stage were not significantly different between the two groups （P=0.170）. Disease-free survival rates stratified by stage and recurrence-free survival rates of gastric cancer were similar between the conventional group and the UAS group （P=0.313 and 0.199, respectively）. The postoperative complication rate was not significantly different between the groups （P=1.000）. Conclusions： It is suggested that the use of UAS in gastrectomy for gastric cancer showed oncologically acceptable safety compared with conventional electric instruments even in long-term period.

Application of Piezoelectric Materials in a Novel Linear Ultrasonic Motor based on Shear-induced Vibration Mode

A novel linear ultrasonic motor based on d15 effect of piezoelectric materials was presented. The design idea aimed at the direct utilization of the shear-induced vibration modes of piezoelectric material. Firstly, the inherent electromechanical coupling mechanism of piezoelectric material was investigated, and shear vibration modes of a piezoelectric shear block was specially designed. A driving point’s elliptical trajectory induced by shear vibration modes was discussed. Then a dynamic model for the piezoelectric shear stator was established with finite element（FE） method to conduct the parametric optimal design. Finally, a prototype based on d15 converse piezoelectric effect is manufactured, and the modal experiment of piezoelectric stator was conducted with laser doppler vibrometer. The experimental results show that the calculated shear-induced vibration modes can be excited completely, and the new linear ultrasonic motor reaches a speed 118 mm/s at noload, and maximal thrust 12.8 N.

Application of Shear Wave Elastography and Contrast-Enhanced Ultrasound in Transrectal Prostate Biopsy

Objective To explore the clinical value of ultrasound shear wave elastography(SWE)and contrast-enhanced ultrasound(CEUS)in transrectal prostate biopsy.Methods A total of 54 patients(average age:67.79±12.01 years)in the experimental group underwent transrectal prostate biopsy under the guidance of SWE,while 46 patients(average age:69.22±11.54 years)in the control group underwent transrectal prostate biopsy guided by CEUS.Results There were a total of 451 needles,with an average of 8.35±1.67 needles per patient in the experimental group,and a total of 462 needles,with an average of 10.04±1.33 needles per patient in the control group.The difference in puncture times between the two groups was statistically significant(P<0.05).There was no significant difference in the positive detection rate,sensitivity or specificity between the two groups(P>0.05),but there was a significant difference in the diagnostic accuracy between the two groups(P<0.05).The E_(mean)and E_(max)of prostate cancer were significantly higher in the experimental group than in benign prostatic hyperplasia(P<0.05).The receiver operating characteristic curve(ROC)analysis showed that the area under the ROC curve(AUC)of E_(mean)was 0.752(S.E.=0.072,95%CI=0.611-0.894,P=0.007),and the best cutoff value was 47.005 kPa.Conclusion In summary,both SWE-and CEUS-guided transrectal prostate biopsy can help find the focus and guide the puncture,and improve the positive detection rate.

Non-destructive Evaluation of Absolute Stress in Steel Members Using Shear-Wave Spectroscopy

Non-destructive measurement of absolute stress in steel members can provide useful information to optimize the design of steel structures and allow the safety of existing structures to be evaluated.This paper investigates the non-destructive capability of ultrasonic shear-wave spectroscopy in absolute stress evaluation of steel members.The effect of steel-member stress on the shear-wave amplitude spectrum is investigated,and a method of absolute stress measurement is proposed.Specifically,the process for evaluating absolute stress using shear-wave spectroscopy is summarized.Two steel members are employed to investigate the relationship between the stress and the frequency in shear-wave echo amplitude spectrum.The H-beam loaded by the universal testing machine is evaluated by the proposed method and the traditional strain gauge method for verification.The results show that the proposed method is effective and accurate for determining absolute stress in steel members.