Force application of laparoscopic surgeons under the impact of heavy personal protective equipment during COVID-19 pandemic

Objective:Surgeons are required to wear heavy personal protective equipment while delivering care to patients during the COVID-19 pandemic.We examined the impact of wearing double gloves on surgeons’performance in laparoscopic surgery.Methods:Eleven surgeons-in-training at the Surgical Simulation Research Lab of the University of Alberta were recruited to perform laparoscopic cutting tasks in simulation while wearing none,one pair,and two pairs of surgical gloves.Forces applied to laparoscopic instruments were measured.Results:Wearing gloves prolonged task times(one pair of gloves:301.6±61.7 s;two pairs of gloves:295.8±65.3 s)compared with no gloves(241.7±46.9 s;p=0.043).Wearing double gloves increased cutting errors(20.4±5.1 mm^(2))compared with wearing one pair of gloves(16.9±5.5 mm^(2))and no gloves(14.4±4.6 mm^(2);p=0.030).Wearing gloves reduced the peak force(one pair of gloves:2.4±0.7 N;two pairs of gloves:2.7±0.6 N;no gloves:3.4±1.4 N;p=0.049),and the total force(one pair of gloves:10.1±2.8 N;two pairs of gloves:10.3±2.6 N;no glove:12.6±1.9 N;p=0.048)delivered onto lapa-roscopic scissors compared with wearing no glove.Conclusion:The combined effects of wearing heavy gloves and using tools reduced the touching sensation,which limited the surgeons’confidence in performing surgical tasks.Increasing practice in simulation is suggested to allow surgeons to overcome difficulties brought by personal protective equipment.

POWER FLOW ANALYSIS AND APPLICATION SIMULATION OF ELECTROMAGNETIC CONTINUOUSLY VARIABLE TRANSMISSION

With the structure of two air gaps and two rotors, the electromagnetic continuously variable transmission（EMCVT） is a novel power-split continuously variable transmission（CVT）. There are two kinds of power flowing through the EMCVT, one is mechanical power and the other is electric power. In the mean time, there are three power ports in the EMCVT, one is the outer rotor named mechanical power port and the other two are the inner rotor and the stator named electric power ports. The mechanical power port is connected to the driving wheels through the final gear and the electric ports are connected to the batteries through the transducers. The two kinds of power are coupled on the outer rotor of the EMCVT. The EMCVT can be equipped on the conventional vehicle being regarded as the CVT and it also can be equipped on the hybrid electric vehicle（HEV） as the multi-energy sources assembly. The power flows of these two kinds of applications are analysed. The back electromotive force（EMF） equations are illatively studied and so the dynamic mathematic model is theorized. In order to certify the feasibility of the above theories, three simulations are carried out in allusion to the above two kinds of mentioned applications of the EMCVT and a five speed automatic transmission（AT） vehicle. The simulation results illustrate that the efficiency of the EMCVT vehicles is higher than that of the AT vehicle owed to the optimized operation area of the engine. Hence the fuel consumption of the EMCVT vehicles is knock-down.