The Experts below are selected from a list of 129 Experts worldwide ranked by ideXlab platform
Tim Horeman - One of the best experts on this subject based on the ideXlab platform.
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Reprocessing Filtering facepiece respirators in primary care using medical autoclave: prospective, bench-to-bedside, single-centre study.
BMJ open, 2020Co-Authors: Ralf E. Harskamp, Bart Van Straten, Jonathan Bouman, Bernadette Van Maltha-van Santvoort, John J. Van Den Dobbelsteen, Joost Rm Van Der Sijp, Tim HoremanAbstract:OBJECTIVE: There are widespread shortages of personal protective equipment as a result of the COVID-19 pandemic. Reprocessing Filtering facepiece particle (FFP)-type respirators may provide an alternative solution in keeping healthcare professionals safe. DESIGN: Prospective, bench-to-bedside. SETTING: A primary care-based study using FFP-2 respirators without exhalation valve (3M Aura 1862+ (20 samples), Maco Pharma ZZM002 (14 samples)), FFP-2 respirators with valve (3M Aura 9322+ (six samples) and San Huei 2920V (16 samples)) and valved FFP type 3 respirators (Safe Worker 1016 (10 samples)). INTERVENTIONS: All masks were reprocessed using a medical autoclave (17 min at 121°C with 34 min total cycle time) and subsequently tested up to three times whether these respirators retained their integrity (seal check and pressure drop) and ability to Filter small particles (0.3-5.0 µm) in the laboratory using a particle penetration test. RESULTS: We tested 33 respirators and 66 samples for Filter Capacity. All FFP-2 respirators retained their shape, whereas half of the decontaminated FFP-3 respirators showed deformities and failed the seal check. The Filtering Capacity of the 3M Aura 1862 was best retained after one, two and three decontamination cycles (0.3 µm: 99.3%±0.3% (new) vs 97.0±1.3, 94.2±1.3% or 94.4±1.6; pl0.001). Of the other FFP-2 respirators, the San Huei 2920 V had 95.5%±0.7% at baseline vs 92.3%±1.7% vs 90.0±0.7 after one-time and two-time decontaminations, respectively (pl0.001). The tested FFP-3 respirator (Safe Worker 1016) had a Filter Capacity of 96.5%±0.7% at baseline and 60.3%±5.7% after one-time decontamination (pl0.001). Breathing and pressure resistance tests indicated no relevant pressure changes between respirators that were used once, twice or thrice. CONCLUSION: This small single-centre study shows that selected FFP-2 respirators may be reprocessed for use in primary care, as the tested masks retain their shape, ability to retain particles and breathing comfort after decontamination using a medical autoclave.
Ralf E. Harskamp - One of the best experts on this subject based on the ideXlab platform.
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Reprocessing Filtering facepiece respirators in primary care using medical autoclave: prospective, bench-to-bedside, single-centre study.
BMJ open, 2020Co-Authors: Ralf E. Harskamp, Bart Van Straten, Jonathan Bouman, Bernadette Van Maltha-van Santvoort, John J. Van Den Dobbelsteen, Joost Rm Van Der Sijp, Tim HoremanAbstract:OBJECTIVE: There are widespread shortages of personal protective equipment as a result of the COVID-19 pandemic. Reprocessing Filtering facepiece particle (FFP)-type respirators may provide an alternative solution in keeping healthcare professionals safe. DESIGN: Prospective, bench-to-bedside. SETTING: A primary care-based study using FFP-2 respirators without exhalation valve (3M Aura 1862+ (20 samples), Maco Pharma ZZM002 (14 samples)), FFP-2 respirators with valve (3M Aura 9322+ (six samples) and San Huei 2920V (16 samples)) and valved FFP type 3 respirators (Safe Worker 1016 (10 samples)). INTERVENTIONS: All masks were reprocessed using a medical autoclave (17 min at 121°C with 34 min total cycle time) and subsequently tested up to three times whether these respirators retained their integrity (seal check and pressure drop) and ability to Filter small particles (0.3-5.0 µm) in the laboratory using a particle penetration test. RESULTS: We tested 33 respirators and 66 samples for Filter Capacity. All FFP-2 respirators retained their shape, whereas half of the decontaminated FFP-3 respirators showed deformities and failed the seal check. The Filtering Capacity of the 3M Aura 1862 was best retained after one, two and three decontamination cycles (0.3 µm: 99.3%±0.3% (new) vs 97.0±1.3, 94.2±1.3% or 94.4±1.6; pl0.001). Of the other FFP-2 respirators, the San Huei 2920 V had 95.5%±0.7% at baseline vs 92.3%±1.7% vs 90.0±0.7 after one-time and two-time decontaminations, respectively (pl0.001). The tested FFP-3 respirator (Safe Worker 1016) had a Filter Capacity of 96.5%±0.7% at baseline and 60.3%±5.7% after one-time decontamination (pl0.001). Breathing and pressure resistance tests indicated no relevant pressure changes between respirators that were used once, twice or thrice. CONCLUSION: This small single-centre study shows that selected FFP-2 respirators may be reprocessed for use in primary care, as the tested masks retain their shape, ability to retain particles and breathing comfort after decontamination using a medical autoclave.
Nicho G. Bouma - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear Preprocessing for Improved Filter Capacity of an Optical Correlator
Integrated Computer-Aided Engineering, 1996Co-Authors: Elizabeth C. Botha, Nicho G. BoumaAbstract:Optical correlation is an efficient parallel implementation of image classifiers. One formulation of the holographic Filter in the optical correlator is the least squares discriminant function LSDF, wherein the shape of the whole correlation function is specified when training the Filter. An issue of particular interest is the Capacity of the Filter, or the number of training images that can be used while still retaining discrimination capability. To investigate the Capacity of an LSDF Filter, and to be more general than just testing on a particular type of image, the fractal dimension of the images was used as an objective complexity measure of the images that the Filter is trained with. Nonlinear preprocessing, specifically edge detection, was used to increase the Filter Capacity and the discriminatory capabilities of the correlator. Simulation experiments of these issues are described and the results are discussed.
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Determining optical-correlator Filter Capacity using fractal dimension as a complexity measure
International Conference on Optical Information Processing, 1994Co-Authors: Elizabeth C. Botha, Nicho G. BoumaAbstract:ABSTRACT Optical correituon is an efficient parallel implementation of image classifiers. One formulation of theholographic Filter in the optical correlator is the Least Squares Discriminant Function (LSDF), whereinthe shape of the whole correlation function is specified when training the Filter. An issue of particular interest is the Capacity of the Filter, or the number of training images that can be used while stillretaining discrimination capability. To investigate the Capacity of an LSDF Filter, and to be more general than just testing on a particular type of image, the fractal dimension of the images was used asan objective complexity measure of the images that the Filter is trained with. Non-linear preprocessing,specifically edge detection, was used to increase the Filter Capacity and the discriminatory capabilities ofthe correlator. Simulation experiments of these issues are described and the results are discussed. 1 INTRODUCTION Optical correlation using a matched spatial Filter[1] was one of the first parallel image recognition systems.In its initial formulation, the optical correlator can only discriminate between the presence (indicated bya peak in the output image) or absence (derived from the absence of a peak) of an object. Since theseearly days, several extensions of the original formulation have been employed [2, 3, 4, 5, 6, 7, 8], of whichthe most important aspects are. incorporating several training images per class, by formulation of the concept synthetic discriminantfunction (SDF)• a formulation for multi-class problems, by specifying a different peak value for each class whentraining the Filter• methods to compensate for possible distortions of the input images, e.g. scale and rotation varia-tions.One of the most recent techniques to combine training images in the holographic Filter of the correlatoris the Least Squares Discriminant Filter (LSDF) formulation of Barnard and Vermeulen[9] wherein theshape of the whole correlation function (output) is specified when training the Filter. We chose thiscorrelation Filter formulation for our experiments, due to its excellent performance.The LSDF Filter was originally formulated as an alternative to the naive "peak vs. no peaK" technique,and a special case of the SDF wherein the shape of the output correlation plane is partially restricted.
Bart Van Straten - One of the best experts on this subject based on the ideXlab platform.
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Reprocessing Filtering facepiece respirators in primary care using medical autoclave: prospective, bench-to-bedside, single-centre study.
BMJ open, 2020Co-Authors: Ralf E. Harskamp, Bart Van Straten, Jonathan Bouman, Bernadette Van Maltha-van Santvoort, John J. Van Den Dobbelsteen, Joost Rm Van Der Sijp, Tim HoremanAbstract:OBJECTIVE: There are widespread shortages of personal protective equipment as a result of the COVID-19 pandemic. Reprocessing Filtering facepiece particle (FFP)-type respirators may provide an alternative solution in keeping healthcare professionals safe. DESIGN: Prospective, bench-to-bedside. SETTING: A primary care-based study using FFP-2 respirators without exhalation valve (3M Aura 1862+ (20 samples), Maco Pharma ZZM002 (14 samples)), FFP-2 respirators with valve (3M Aura 9322+ (six samples) and San Huei 2920V (16 samples)) and valved FFP type 3 respirators (Safe Worker 1016 (10 samples)). INTERVENTIONS: All masks were reprocessed using a medical autoclave (17 min at 121°C with 34 min total cycle time) and subsequently tested up to three times whether these respirators retained their integrity (seal check and pressure drop) and ability to Filter small particles (0.3-5.0 µm) in the laboratory using a particle penetration test. RESULTS: We tested 33 respirators and 66 samples for Filter Capacity. All FFP-2 respirators retained their shape, whereas half of the decontaminated FFP-3 respirators showed deformities and failed the seal check. The Filtering Capacity of the 3M Aura 1862 was best retained after one, two and three decontamination cycles (0.3 µm: 99.3%±0.3% (new) vs 97.0±1.3, 94.2±1.3% or 94.4±1.6; pl0.001). Of the other FFP-2 respirators, the San Huei 2920 V had 95.5%±0.7% at baseline vs 92.3%±1.7% vs 90.0±0.7 after one-time and two-time decontaminations, respectively (pl0.001). The tested FFP-3 respirator (Safe Worker 1016) had a Filter Capacity of 96.5%±0.7% at baseline and 60.3%±5.7% after one-time decontamination (pl0.001). Breathing and pressure resistance tests indicated no relevant pressure changes between respirators that were used once, twice or thrice. CONCLUSION: This small single-centre study shows that selected FFP-2 respirators may be reprocessed for use in primary care, as the tested masks retain their shape, ability to retain particles and breathing comfort after decontamination using a medical autoclave.
Joost Rm Van Der Sijp - One of the best experts on this subject based on the ideXlab platform.
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Reprocessing Filtering facepiece respirators in primary care using medical autoclave: prospective, bench-to-bedside, single-centre study.
BMJ open, 2020Co-Authors: Ralf E. Harskamp, Bart Van Straten, Jonathan Bouman, Bernadette Van Maltha-van Santvoort, John J. Van Den Dobbelsteen, Joost Rm Van Der Sijp, Tim HoremanAbstract:OBJECTIVE: There are widespread shortages of personal protective equipment as a result of the COVID-19 pandemic. Reprocessing Filtering facepiece particle (FFP)-type respirators may provide an alternative solution in keeping healthcare professionals safe. DESIGN: Prospective, bench-to-bedside. SETTING: A primary care-based study using FFP-2 respirators without exhalation valve (3M Aura 1862+ (20 samples), Maco Pharma ZZM002 (14 samples)), FFP-2 respirators with valve (3M Aura 9322+ (six samples) and San Huei 2920V (16 samples)) and valved FFP type 3 respirators (Safe Worker 1016 (10 samples)). INTERVENTIONS: All masks were reprocessed using a medical autoclave (17 min at 121°C with 34 min total cycle time) and subsequently tested up to three times whether these respirators retained their integrity (seal check and pressure drop) and ability to Filter small particles (0.3-5.0 µm) in the laboratory using a particle penetration test. RESULTS: We tested 33 respirators and 66 samples for Filter Capacity. All FFP-2 respirators retained their shape, whereas half of the decontaminated FFP-3 respirators showed deformities and failed the seal check. The Filtering Capacity of the 3M Aura 1862 was best retained after one, two and three decontamination cycles (0.3 µm: 99.3%±0.3% (new) vs 97.0±1.3, 94.2±1.3% or 94.4±1.6; pl0.001). Of the other FFP-2 respirators, the San Huei 2920 V had 95.5%±0.7% at baseline vs 92.3%±1.7% vs 90.0±0.7 after one-time and two-time decontaminations, respectively (pl0.001). The tested FFP-3 respirator (Safe Worker 1016) had a Filter Capacity of 96.5%±0.7% at baseline and 60.3%±5.7% after one-time decontamination (pl0.001). Breathing and pressure resistance tests indicated no relevant pressure changes between respirators that were used once, twice or thrice. CONCLUSION: This small single-centre study shows that selected FFP-2 respirators may be reprocessed for use in primary care, as the tested masks retain their shape, ability to retain particles and breathing comfort after decontamination using a medical autoclave.