Teaching medical physics experiment with the history of physics has a uniquely important effect on raising students'interests and scientific spirit,helping then understand physics knowledge,and strengthening their experiment ability and comprehensive quality.

Objective To vividly display the forming principle of anthropometric ECG by using mannequin.Methods A mannequin was made using conductive paper with"heart" designed in left chest and its ECG was measured.Results The forming principles of ECG from mannequin and real people were identical.Mannequin had the same physical characteristics as real human body.Conclusion The change of ECG caused by pure physical factors can be studied by using the mannequin,which helps doctors properly analyze ECG and make accurate diagnosis.

By using the image processing function and programming tomography,the following functions are realized: the contour line,edge line and gradation histogram of medical images are displayed;the selected regions of medical images are freely zoomed;the gray level of discretional regions is displayed using medical image processing tool and the distance of the given points is freely measured.

Objective To evaluate the effects of different right ventricular pacing sites on left ventricular systolic synchrony using tissue Doppler imaging(TDI).Methods A tota[of sixty-nine patients with indications for permanent pacemaker implantation were enrolled sequentially by Pace-ROAD study(Pacemaker-right ventricular outflow tract and apex study,a randomized control study).They were randomized to RVOT pacing group(group A)or RVA pacing group(group B).Echocardiographic study with TDl was performed before and after 3 month follow up,and the data were analysed off-line.The peak velocity(Vs),the time to the peak of S wave(Ts)of all 12 basal and middle segments of left ventricle were measured,and then the standard deviation of Ts(Ts-SD),the average of Vs(Vs-M)were calculated.Results Thirty-six patients were randomized to group A,while the other 33 patients to group B.In each group,one patient was rejected due to non-pacing rhythm during follow-up.After 3 month pacing,the Ts-SD of group A was significantly shorter than that of group B[(23.63±2.32)ms vs(31.54±2.93)ms.P=0.0387-].In the patients with the basal Ts-SD longer than 32.6 ms(group A2 and group B2),the Ts-SD was significantly shortened than the baseline in group A2 during follow-up,while no significant difference was found in group B2.And the follow-up Ts-SD of group B2 was significantly longer than that of group A2 r(38.19±18.34)ms vs(28.55±16.93)ms,P=0.0290].Conclusions RVOT pacing is associated with favorable left ventricular systolic synchrony than RVA pacing,especially in patients with worsened baseline systolic synchrony.