Sizing of airborne particles in an operating room

Medical procedures that produce aerosolized particles are under great scrutiny due to the recent concerns surrounding the COVID-19 virus and increased risk for nosocomial infections. For example, thoracostomies, tracheotomies and intubations/extubations produce aerosols that can linger in the air. The lingering time is dependent on particle size where, e.g., 500 μm (0.5 mm) particles may quickly fall to the floor, while 1 μm particles may float for extended lengths of time. Here, a method is presented to characterize the size of <40 μm to >600 μm particles resulting from surgery in an operating room (OR). The particles are measured in-situ (next to a patient on an operating table) through a 75mm aperture in a ∼400 mm rectangular enclosure with minimal flow restriction. The particles and gasses exiting a patient are vented through an enclosed laser sheet while a camera captures images of the side-scattered light from the entrained particles. A similar optical configuration was described by Anfinrud et al.; however, we present here an extended method which provides a calibration method for determining particle size. The use of a laser sheet with side-scattered light provides a large FOV and bright image of the particles; however, the particle image dilation caused by scattering does not allow direct measurement of particle size. The calibration routine presented here is accomplished by measuring fixed particle distribution ranges with a calibrated shadow imaging system and mapping these measurements to the in-situ imaging system. The technique used for generating and measuring these particles is described. The result is a three-part process where 1) particles of varying sizes are produced and measured using a calibrated, high-resolution shadow imaging method, 2) the same particle generators are measured with the in-situ imaging system, and 3) a correlation mapping is made between the (dilated) laser image size and the measured particle size. Additionally, experimental and operational details of the imaging system are described such as requirements for the enclosure volume, light management, air filtration and control of various laser reflections. Details related to the OR environment and requirements for achieving close proximity to a patient are discussed as well.

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Streulicht-Partikelgrößen-Zählanalyse als Methode für In-situ- Messungen in Gas-Partikel-Strömungen/ Scattered light particle size counting analysis - a technique for true in situ measurement within gas-particle flows

tm - Technisches Messen ◽

10.1524/teme.1989.56.jg.213 ◽

1989 ◽

Vol 56 (JG) ◽

pp. 213-221

Author(s):

H. Umhauer

Keyword(s):

Particle Size ◽

Scattered Light ◽

In Situ Measurement ◽

Light Particle ◽

Particle Flows

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A mobile high-field magnetic resonance imaging system for neurosurgery

Neurosurgical FOCUS ◽

10.3171/foc.1999.6.3.9 ◽

1999 ◽

Vol 6 (3) ◽

pp. E8 ◽

Cited By ~ 8

Author(s):

Garnette R. Sutherland ◽

Taro Kaibara ◽

Deon Louw ◽

John Saunders

Keyword(s):

Magnetic Resonance ◽

Mr Imaging ◽

Operating Room ◽

Imaging System ◽

Standard Of Care ◽

Anesthetic Techniques ◽

Magnetic Resonance Imaging System ◽

Operating Table ◽

High Definition ◽

Neurosurgical Patients

The authors' goal was to place a mobile, 1.5 tesla magnetic resonance (MR) imaging system into a neurosurgical operating room without adversely affecting established neurosurgical management. The system would help to plan accurate surgical corridors, confirm the accomplishment of operative objectives, and detect acute complications such as hemorrhage or ischemia. The authors used an actively shielded 1.5 tesla magnet, together with 15 m tesla/m gradients, MR console computers, gradient amplifiers, a titanium, hydraulic-controlled operating table, and a radio frequency coil that can be disassembled. The magnet is moved to and from the surgical field by using overhead crane technology. To date, the system has provided unfettered access to 46 neurosurgical patients. In all patients, high-definition T1- and/or T2-weighted images were rapidly and reproducibly acquired at various stages of the surgical procedures. Eleven patients underwent craniotomy that was optimized after pre-incisional imaging. In four patients who harbored subtotally resected tumor, intraoperative MR imaging allowed removal of remaining tumor. Interestingly, the intraoperative administration of gadolinium in the management of patients with malignant glioma demonstrated a dynamic expansion of enhancement beyond the preoperative contrast contour. These zones of new enhancement proved, on examination of biopsy sample, to be tumor. The authors have demonstrated that high-quality MR images can be obtained within reasonable time constraints in the operating room. Procedures can be conducted without compromising or altering traditional neurosurgical, nursing, or anesthetic techniques. It is feasible that within the next decade intraoperative MR imaging may become the standard of care in neurosurgery.

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A mobile high-field magnetic resonance system for neurosurgery

Journal of Neurosurgery ◽

10.3171/jns.1999.91.5.0804 ◽

1999 ◽

Vol 91 (5) ◽

pp. 804-813 ◽

Cited By ~ 207

Author(s):

Garnette R. Sutherland ◽

Taro Kaibara ◽

Deon Louw ◽

David I. Hoult ◽

Boguslaw Tomanek ◽

...

Keyword(s):

Magnetic Resonance ◽

Mr Imaging ◽

Operating Room ◽

Imaging System ◽

Anesthetic Techniques ◽

Operating Table ◽

High Definition ◽

Content Type ◽

Neurosurgical Patients ◽

Fine Print

Object. The authors' goal was to place a mobile, 1.5-tesla magnetic resonance (MR) imaging system into a neurosurgical operating room without adversely affecting established neurosurgical management. The system would help to plan accurate surgical corridors, confirm the accomplishment of operative objectives, and detect acute complications such as hemorrhage or ischemia.Methods. The authors used an actively shielded 1.5-tesla magnet, together with 15 mtesla/m gradients, MR console computers, gradient amplifiers, a titanium, hydraulic-controlled operating table, and a radiofrequency coil that can be disassembled. The magnet is moved to and from the surgical field by using overhead crane technology. To date, the system has provided unfettered access in 46 neurosurgical patients.In all patients, high-definition T1- and/or T2-weighted images were rapidly and reproducibly acquired at various stages of the surgical procedures. Eleven patients underwent craniotomy that was optimized after preincision imaging. In four patients who harbored subtotally resected tumor, intraoperative MR imaging aided the surgeon in removing the remaining tumor. Interestingly, the intraoperative administration of gadolinium demonstrated a dynamic expansion of enhancement beyond the preoperative contrast contour in patients with malignant glioma. These zones of new enhancement proved, on examination of biopsy samples, to be tumor.Conclusions. The authors have demonstrated that high-quality MR images can be obtained in the operating room within reasonable time constraints. Procedures can be conducted without compromising or altering traditional neurosurgical, nursing, or anesthetic techniques. It is feasible that within the next decade intraoperative MR imaging may become the standard of care in neurosurgery.

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Planning Premises and Design Considerations for Hybrid Operating Room

International Journal of Research Foundation of Hospital and Health Care Administration ◽

10.5005/jp-journals-10035-1015 ◽

2014 ◽

Vol 2 (1) ◽

pp. 50-56 ◽

Cited By ~ 1

Author(s):

Sunil Kant ◽

Shakti Kumar Gupta ◽

V Siddharth

Keyword(s):

Operating Room ◽

Imaging System ◽

Care Delivery ◽

Cost Of Care ◽

Operating Table ◽

Hybrid Operating Room ◽

Surgical Equipment ◽

Design Considerations ◽

X Ray Imaging ◽

Operating Suite

ABSTRACT The hybrid operating room can be defined as the combination of imaging system and operating table installed in an operating theater room for, e.g. use of an angiography imaging system and operation table in an operation theatre or use of an operating table in angiography room. Shorter patient recovery time, decreased length of stay, streamlined care delivery, improvement in cross-specialty communication, minimized risk for communication-related errors across clinical specialties and lower overall cost of care are some of the advantages of the hybrid operating room. Although no/limited data exists in the literature, the potential disadvantages of hybrid operating suite are cost, infection, prolonged anesthesia and radiation exposure. The primary components of a hybrid operating suite are an imaging system and imaging compatible operation table. Area required for hybrid operating suite varies from 80 to 150 m2. The most common configuration of hybrid operating suite includes a flat panel angiographic X-ray imaging system and surgical equipment for cardiac surgery. How to cite this article Siddharth V, Kant S, Chandrashekhar R, Gupta SK. Planning Premises and Design Considerations for Hybrid Operating Room. Int J Res Foundation Hosp Healthc Adm 2014;2(1):50-56.

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Inspection of Large Droplets in Fuel Sprays Using a Gaussian Laser-Sheet: An Experimental Approach

ISRN Optics ◽

10.5402/2012/691637 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Rami Zakaria

Keyword(s):

Light Scattering ◽

Laser Beam ◽

High Speed ◽

Imaging System ◽

Scattered Light ◽

Laser Sheet ◽

Injection System ◽

High Temporal Resolution ◽

Ic Engine ◽

Fuel Sprays

A laser sheet imaging system was developed for the investigation of high-speed fuel sprays under a relatively low injection pressure (less than 1 MPa). A pulsed laser and high-resolution CCD cameras were used for the evaluation of the fuel injection system of a small IC engine. Large droplets were detected during the injection incident, with a variation in the scattered light pattern from one droplet to another. The light scattering pattern of individual droplets was investigated in order to study the interaction between the laser beam and large fluid droplets compared to the wavelength. A laser sheet, with a wide waist Gaussian profile, was used for illumination, so that the relative position of a droplet in the third dimension of the field of view (FOV) can be estimated from the 2D-image. Light scattering images were processed in order to closely investigate the structure of the fuel droplets, and the behaviour of the laser beam when encountering large droplets (0.2–1.4 mm). The Particle Image Velocimetry (PIV) method was applied on the double exposure spray images to calculate the droplet velocity distribution of the global spray, using a high temporal resolution (15 s).

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Novel Formulation Development and Evaluation of Nanoparticles Based in Situ Gelling System for The Ophthalmic Delivery of Ciprofloxacin Hydrochloride

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v5i4.8880 ◽

2015 ◽

Vol 5 (4) ◽

Author(s):

Kranti Singh ◽

Surajpal Verma ◽

Shyam Prasad ◽

Indu Bala

Keyword(s):

Particle Size ◽

Zeta Potential ◽

Drug Loading ◽

In Vitro Release ◽

Formulation Development ◽

Ciprofloxacin Hydrochloride ◽

Potential Value ◽

The Mean ◽

In Situ Gelling

Ciprofloxacin hydrochloride loaded Eudragit RS100 nanoparticles were prepared by using w/o/w emulsification (multiple emulsification) solvent evaporation followed by drying of nanoparticles at 50°C. The nanoparticles were further incorporated into the pH-triggered in situ gel forming system which was prepared using Carbopol 940 in combination with HPMC as viscosifying agent. The developed nanoparticles was evaluated for particle size, zeta potential value and loading efficiency; nanoparticle incorporated in situ gelling system was evaluated for pH, clarity, gelling strength, rheological studies, in-vitro release studies and ex-vivo precorneal permeation studies. The nanopaticle showed the mean particle size varying between 263.5nm - 325.9 nm with the mean zeta potential value of -5.91 mV to -8.13 mV and drug loading capacity varied individually between 72.50% to 98.70% w/w. The formulation was clear with no suspended particles, showed good gelling properties. The gelling was quick and remained for longer time period. The developed formulation was therapeutically efficacious, stable and non-irritant. It provided the sustained release of drug over a period of 8-10 hours.

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