Figure 1 - available via license: Creative Commons Attribution 4.0 International
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Schematic illustration of a typical (a) jet nebulizer; (b) ultrasonic nebulizer (adapted from O'Callaghan and Barry (1997)).
Source publication
Introduction
Optical microscope images can be useful to evaluate nebulizers considering the size of droplets produced by these devices. From this perspective, the proposed method was compared to the classic concept of Mass Median Aerodynamic Diameter (MMAD) for the ideal droplet size between 0.5-5.5 µm.
Methods
We tested a sample of five home nebu...
Context in source publication
Citations
... In our study the AeroEclipse as an intermittent nebulizer had the highest MMAD. Variation in MMAD values between nebulizers can be related to the differences in design between each nebulizer [35]. That could be the reason the even though it delivered higher TED there was no significant difference in the FPD, and the FPF [33,34]. ...
Objective
Nebulizers can be divided according to their functional principle into jet, ultrasonic and vibrating mesh nebulizers with intermittent or continuous aerosol delivery and may be used with many different adapters and connections and all can influence their efficiency. The aim of the present work was to evaluate the effect functional principle, delivery technique, and connection used on aerosol delivered from four different nebulizers.
Methods
Four nebulizers were used in the study; three of them were jet nebulizers (JNs; AeroEclipse, NebuTech, En ful Kit) and one of them was Aerogen Solo vibrating mesh nebulizers (VMN). AeroEclipse and NebuTech are intermittent output nebulizers, while the rest are continuous output nebulizers. Aerogen Solo was used with either a standard T-piece or Aerogen Ultra holding chamber, and En ful Kit was used with a standard T-piece or Circulaire II holding chamber. 2ml of salbutamol was nebulized to determine the total emitted dose (TED) and aerodynamic droplet characteristics of the emitted aerosol from the 6 different sets (4 nebulizers with T-piece and 2 holding chambers).
Results
The mean±SD TED from VMN was significantly higher than all the JNs (p<0.05). Aerogen Ultra with VMN did not show a significant effect on TED compare to T-piece, but it significantly increased (p<0.05) fine particle dose (FPD; 3091.5±189.4 μg) and fine particle fraction (FPF; 72.7±3.6%). However, the Circulaire II with En ful Kit had significantly higher TED, FPD, and FPF compared to T-piece (p<0.05). Intermittent JNs (AeroEclipse and NebuTech) had significantly higher TED (p<0.05) compared to the continuous JNs (En ful Kit) with no significant effect on the other parameters studied. AeroEclipse had the highest MMAD and Aerogen Solo Ultra has the lowest in MMAD.
Conclusions
The functional principle, delivery technique, and connection used had a significant effect on aerosol delivered from nebulizers. VMNs are significantly better than JNs. Intermittent delivery has significantly better TED than continuous delivery. Holding chamber with both VMNs and JNs improved aerosol delivery compared to standard T-piece.
... The non-diffracted light is focused on the central detector. In this way, a diffraction pattern of all contributing particles is recorded as a function of the dispersion angle [24], [25]. ...
Currently, several drugs are being used systemically to treat Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). However, few studies discuss the possibility of using the inhalation route for this treatment. Pneumatic and ultrasonic nebulizers are increasingly used due to the ease with which these media deliver drugs through an aerosol suspension to deliver drugs in a localized manner in the respiratory tract, providing greater efficiency of absorption. This study aims to characterize the droplet diameters by bands of "breathable particles" generated by nebulizers commercialized in Brazil (2 pneumatic and 1 ultrasonic), using the direct laminar incidence (DLI) technique. In addition, to discuss the use of drugs by inhalation based on the physicochemical and pharmacology properties. In the nebulization procedure, the images of the dispersed aero droplets were captured using the DLI technique. Droplet diameter distribution histograms were elaborated, emphasizing the range of droplets with diameters between 1.0 to 5.0 µm. The results attested that each nebulizer has its own characteristic of delivering the aerodynamic suspension in the nebulization process. In this study, DLI represents a viable alternative for characterization of the aero dispersed droplets, of drugs used worldwide to treat SARS-CoV-2 signs and symptoms.
Objective
To create an aerosol containment mask (ACM) for common otolaryngologic endoscopic procedures that also provides nanoparticle-level protection to patients.
Study Design
Prospective feasibility study .
Setting
In-person testing with a novel ACM.
Methods
The mask was designed in Solidworks and 3D printed. Measurements were made on 10 healthy volunteers who wore the ACM while reading the Rainbow Passage repeatedly and performing a forced cough or sneeze at 5-second intervals over 1 minute with an endoscope in place.
Results
There was a large variation in the number of aerosol particles generated among the volunteers. Only the sneeze task showed a significant increase compared with normal breathing in the 0.3-µm particle size when compared with a 1-tailed t test ( P = .013). Both the 0.5-µm and 2.5-µm particle sizes showed significant increases for all tasks, while the 2 largest particle sizes, 5 and 10 µm, showed no significant increase (both P < .01). With the suction off, 3 of 30 events (2 sneeze events and 1 cough event) had increases in particle counts, both inside and outside the mask. With the suction on, 2 of 30 events had an increase in particle counts outside the mask without a corresponding increase in particle counts inside the mask. Therefore, these fluctuations in particle counts were determined to be due to random fluctuation in room particle levels.
Conclusion
ACM will accommodate rigid and flexible endoscopes plus instruments and may prevent the leakage of patient-generated aerosols, thus avoiding contamination of the room and protecting health care workers from airborne contagions.
Level of evidence
2
Objective
To create an aerosol containment mask (ACM) that contains aerosols during common otolaryngologic endoscopic procedures while protecting patients from environmental aerosols.
Study Design
Bench testing.
Setting
Mannequin testing.
Methods
The mask was designed in SolidWorks and 3-dimensional printed. Mannequins were fitted with a nebulizer to generate aerosols. Commercial particle counters were used to measure mask performance.
Results
The ACM has 2 ports on either side for instruments and endoscopes, a port for a filter, and a port that can evacuate aerosols contained within the mask via a standard suction pump. The mask contained aerosols on a mannequin with and without facial hair when the suction was set to 18.5 L/min. Other types of masks demonstrated substantial aerosol leakage under similar conditions. In a subsequent experiment, the ACM contained aerosols generated by a nebulizer up to the saturation of the particle detector without measurable leakage with or without suction.
Conclusion
The ACM will accommodate rigid and flexible endoscopes plus instruments and prevent leakage of patient-generated aerosols, thus avoiding contamination of the room and protecting health care workers from airborne contagions.
Level of evidence
2.
