An introduction to the classified management of such trials and clinical application,documents submission for ethical review,operating procedures and review key points,as well as the problems found in the review.These efforts aim to provide guidance to the review of medical technique clinical trials,and to promote ethical supervision for new medical techniques.

To understand the local hemodynamics of modified TF-AHCB carotid bifurcation model, using particle image velocimetry technique to measure the instantaneous velocity distribution of the model attatched to a circuit. The velocity was controlled by regulating the height of the reservoir. The working fluid consists of glycerine and water mixture with viscosity of 3.75 mPa.s similar to human blood. Instantaneous velocity fields were obtained by PIV and the shear stresses were calculated according to the velocity. The results showed that inside the model, there were a large flow separation and an anticlockwise rotating vortex on the lateral wall of ICA, The location and distance of the vortex changed with the flow velocity. The higher the flow velocity, the smaller the vortex distance, and the farther the location. The shear stresses on the lateral wall were significantly lower in all work condition. And there a low shear stress kernel when the velocity was lower than 0.839 m/s. The location of the low shear stress was just the position of atherosclerosis. The flow pattern inside the model consists of large flow separation and vortex zones. And there are low shear stress zones at the lateral wall of ICA, Where are thought to be associated with the genesis of atherosclerosis.
Blood Flow Velocity ; Carotid Arteries ; physiology ; Models, Cardiovascular ; Pulsatile Flow ; Regional Blood Flow ; physiology ; Rheology ; methods ; Stress, Mechanical

Objective:To monitor intra-fractional set-up errors in tumor radiotherapy using a real-time intelligent capture system for precision displacement.Methods:A simulated radiotherapy environment was created in both the laboratory and the treatment room. A three-axis ( xyz) displacement platform (LD60-LM) and dial gauges were used as displacement measurement tools. Moreover, a real-time intelligent capture system for precision displacement was developed for displacement monitoring. With 23 patients treated with radiotherapy enrolled in this study, the above system was employed to monitor their intra-fractional set-up errors in fractionated radiotherapy. Descriptive analyses were conducted on the deviations between the data captured by cameras and the actual displacement, obtaining the mean values and standard deviation. Results:The monitoring calibration data from the laboratory revealed displacement differences of ≤ 0.5 mm within 20 mm and a maximum displacement difference of 1.47 mm for 50 mm. In contrast, the calibration result from the treatment room exhibited deviations of ± 0.2 mm on the y- z axes, as displayed by both the left and right cameras, and ± 0.31 mm on the x- z axes, as displayed by the middle camera. During 37 radiotherapy sessions in 23 patients, the monitoring result from the middle camera revealed five deviations exceeding the threshold of 5 mm, with the maximum deviation duration and displacement of 57.2 s and 9.24 mm, respectively. Conclusions:The real-time intelligent capture system for precision displacement based on machine vision can achieve real-time monitoring of set-up errors during tumor radiotherapy. Nevertheless, further improvements and service testing are necessary for this system.