High Speed Photographic Detection of Particle Distribution During Aerosol and Smoke Generating Surgical Procedures: Effects of Surgical Site Evacuation

Objective: Determine the effectiveness of evacuation systems designed to clear bioaerosols and smoke from the surgical field. Study design: High-speed photographic evaluation of aerosol and smoke generated in simulated surgical fields. Materials and methods: Surgical site aerosol clearance was evaluated using a model of the anterior neck and prototypes for surgical site evacuator ports created using 3D printing. A commercially available electrocautery handpiece fitted with an evacuator was tested on animal tissue for smoke clearance. Both systems were connected to a commercial vacuum powered evacuation system. High speed photography was used to record videos of the aerosols and plumes. Fields were recorded with and without evacuation. Results: Efficient aerosol clearance from an open surgical field using an evacuator port is dependent upon the port design, airflow velocity, and placement relative to the aerosol generating site. The size and surface geometry of the surgical field are also important. Surgical smoke generated with electrocautery is cleared from the field by the evacuation enclosure around the handpiece, even at high electrocautery power settings. Except for device noise, there appears to be no reason for using evacuator flow rates below the maximum setting. Conclusions: Bioaerosol and smoke generated during surgery are potential sources of respiratory pathogens and pose a threat to operating room personnel. Surgical site evacuation can significantly reduce the volume of airborne particles in the field but requires careful design and deployment considerations.

Влияние рассеянных электронов на коэффициент шума циклотронных защитных устройств

The influence of the scattered electrons of the beam on the noise parameters of cyclotron protective devices (CPD) of the microwave range is experimentally investigated. It is shown that the beam electrons scattered by the residual gas particles are a source of additional device noise. As an object of research we used commercially available samples of the CPD.

Noise test method for dual-gate MOSFET device

In recent years, with the development of mesoscopic physics and nanoelectronics, the research on noise and testing technology of electronic components has been developed. It is well known that noise can characterize the transmission characteristics of carriers in nanoscale electronic components. With the continuous shrinking of the device size, the carrier transport of nanoscale MOSFET devices has been gradually transformed from the traditional drift-diffusion to become the quasi-ballistic or ballistic transport, and its current noise contains granular and thermal noise. The paper by Jeon et al. [The first observation of shot noise characteristics in 10-nm scale MOSFETs, in Proc. 2009 Symp. VLSI Technology (IEEE, Honolulu, 2009), pp. 48–49] presents the variation relation of 20 nm MOSFET current noise with source–drain current and voltage, and its current noise characteristic is between thermal noise and shot noise, so 20 nm MOSFET current noise is shot noise and thermal noise. The paper by Navid et al. [J. Appl. Phys. 101 (2007) 124501] shows through simulation that the 60 nm MOSFET current noise is suppressed shot noise and thermal noise. At present, the current noise has seriously affected the basic performance of the device, thus the circuit cannot work normally. Therefore, it is necessary to study the generation mechanism and characteristics of current noise in electronic components so as to suppress device noise, which can not only realize the reduction of device noise, but also play a positive role in the work-efficiency, life-span and reliability of electronic components.