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2.
Crit Care ; 26(1): 338, 2022 11 04.
Article in English | MEDLINE | ID: covidwho-2108872

ABSTRACT

We conducted a proof of concept study where Anapnoguard endotracheal tubes and its control unit were used in 15 patients with COVID-19 acute respiratory distress syndrome. Anapnoguard system provides suction, venting, rinsing of subglottic space and controls cuff pressure detecting air leakage through the cuff. Alpha-amylase and pepsin levels, as oropharyngeal and gastric microaspiration markers, were assessed from 85 tracheal aspirates in the first 72 h after connection to the system. Oropharyngeal microaspiration occurred in 47 cases (55%). Episodes of gastric microaspiration were not detected. Patient positioning, either prone or supine, did not affect alpha-amylase and pepsin concentration in tracheal secretions. Ventilator-associated pneumonia (VAP) rate was 40%. The use of the AG system provided effective cuff pressure control and subglottic secretions drainage. Despite this, no reduction in the incidence of VAP has been demonstrated, compared to data reported in the current COVID-19 literature. The value of this new technology is worth of being evaluated for the prevention of ventilator-associated respiratory tract infections.


Subject(s)
COVID-19 , Pneumonia, Ventilator-Associated , Respiratory Distress Syndrome , Humans , Intensive Care Units , Pepsin A , Pronation , Equipment Design , Pneumonia, Ventilator-Associated/etiology , Intubation, Intratracheal/adverse effects , alpha-Amylases
3.
Sensors (Basel) ; 22(15)2022 Aug 08.
Article in English | MEDLINE | ID: covidwho-1994141

ABSTRACT

The development of MEMS acoustic resonators meets the increasing demand for in situ detection with a higher performance and smaller size. In this paper, a lithium niobate film-based S1 mode Lamb wave resonator (HF-LWR) for high-sensitivity gravimetric biosensing is proposed. The fabricated resonators, based on a 400-nm X-cut lithium niobate film, showed a resonance frequency over 8 GHz. Moreover, a PMMA layer was used as the mass-sensing layer, to study the performance of the biosensors based on HF-LWRs. Through optimizing the thickness of the lithium niobate film and the electrode configuration, the mass sensitivity of the biosensor could reach up to 74,000 Hz/(ng/cm2), and the maximum value of figure of merit (FOM) was 5.52 × 107, which shows great potential for pushing the performance boundaries of gravimetric-sensitive acoustic biosensors.


Subject(s)
Acoustics , Biosensing Techniques , Electrodes , Equipment Design , Vibration
4.
Nat Med ; 28(8): 1538, 2022 08.
Article in English | MEDLINE | ID: covidwho-1991644
5.
PLoS One ; 17(6): e0268542, 2022.
Article in English | MEDLINE | ID: covidwho-1987130

ABSTRACT

Proper respiratory tract protection is the key factor to limiting the rate of COVID-19 spread and providing a safe environment for health care workers. Traditional N95 (FFP2) respirators are not easy to regenerate and thus create certain financial and ecological burdens; moreover, their quality may vary significantly. A solution that would overcome these disadvantages is desirable. In this study a commercially available knit polyester fleece fabric was selected as the filter material, and a total of 25 filters of different areas and thicknesses were prepared. Then, the size-resolved filtration efficiency (40-400 nm) and pressure drop were evaluated at a volumetric flow rate of 95 L/min. We showed the excellent synergistic effect of expanding the filtration area and increasing the number of filtering layers on the filtration efficiency; a filter cartridge with 8 layers of knit polyester fabric with a surface area of 900 cm2 and sized 25 × 14 × 8 cm achieved filtration efficiencies of 98% at 95 L/min and 99.5% at 30 L/min. The assembled filter kit consists of a filter cartridge (14 Pa) carried in a small backpack connected to a half mask with a total pressure drop of 84 Pa at 95 L/min. In addition, it is reusable, and the filter material can be regenerated at least ten times by simple methods, such as boiling. We have demonstrated a novel approach for creating high-quality and easy-to-breathe-through respiratory protective equipment that reduces operating costs and is a green solution because it is easy to regenerate.


Subject(s)
COVID-19 , Respiratory Protective Devices , Aerosols , COVID-19/prevention & control , Equipment Design , Filtration/methods , Humans , Masks , Materials Testing/methods , Polyesters
7.
PLoS One ; 17(6): e0254736, 2022.
Article in English | MEDLINE | ID: covidwho-1933199

ABSTRACT

In bioinformatics, alignment is an essential technique for finding similarities between biological sequences. Usually, the alignment is performed with the Smith-Waterman (SW) algorithm, a well-known sequence alignment technique of high-level precision based on dynamic programming. However, given the massive data volume in biological databases and their continuous exponential increase, high-speed data processing is necessary. Therefore, this work proposes a parallel hardware design for the SW algorithm with a systolic array structure to accelerate the forward and backtracking steps. For this purpose, the architecture calculates and stores the paths in the forward stage for pre-organizing the alignment, which reduces the complexity of the backtracking stage. The backtracking starts from the maximum score position in the matrix and generates the optimal SW sequence alignment path. The architecture was validated on Field-Programmable Gate Array (FPGA), and synthesis analyses have shown that the proposed design reaches up to 79.5 Giga Cell Updates per Second (GCPUS).


Subject(s)
Algorithms , Computational Biology , Computational Biology/methods , Databases, Factual , Equipment Design , Sequence Alignment , Software
8.
Am J Med ; 135(11): 1280-1281, 2022 11.
Article in English | MEDLINE | ID: covidwho-1926170

Subject(s)
Masks , Policy , Humans , Equipment Design
9.
Nat Commun ; 13(1): 513, 2022 01 26.
Article in English | MEDLINE | ID: covidwho-1915267

ABSTRACT

Loss of photoreceptors in atrophic age-related macular degeneration (AMD) results in severe visual impairment. Since the low-resolution peripheral vision is retained in such conditions, restoration of central vision should not jeopardize the surrounding healthy retina and allow for simultaneous use of the natural and prosthetic sight. This interim report, prespecified in the study protocol, presents the first clinical results with a photovoltaic substitute of the photoreceptors providing simultaneous use of the central prosthetic and peripheral natural vision in atrophic AMD. In this open-label single group feasibility trial (NCT03333954, recruitment completed), five patients with geographic atrophy have been implanted with a wireless 2 x 2 mm-wide 30 µm-thick device, having 378 pixels of 100 µm in size. All 5 patients achieved the primary outcome of the study by demonstrating the prosthetic visual perception in the former scotoma. The four patients with a subretinal placement of the chip demonstrated the secondary outcome: Landolt acuity of 1.17 ± 0.13 pixels, corresponding to the Snellen range of 20/460-20/565. With electronic magnification of up to a factor of 8, patients demonstrated prosthetic acuity in the range of 20/63-20/98. Under room lighting conditions, patients could simultaneously use prosthetic central vision and their remaining peripheral vision in the implanted eye and in the fellow eye.


Subject(s)
Electric Stimulation Therapy/instrumentation , Electric Stimulation Therapy/methods , Geographic Atrophy/therapy , Macular Degeneration/therapy , Vision Disorders/therapy , Visual Perception , Visual Prosthesis , Aged , Aged, 80 and over , Electric Stimulation , Equipment Design , Eyeglasses , Humans , Retina , Treatment Outcome , Visual Acuity
10.
Sensors (Basel) ; 22(13)2022 Jun 27.
Article in English | MEDLINE | ID: covidwho-1911522

ABSTRACT

The recent SARS-CoV2 pandemic has put a great challenge on university courses. Electronics teaching requires real laboratory experiences for students, which cannot be realized if access to physical infrastructures is prohibited. A possible solution would be to distribute to students, at home, electronics equipment suitable for laboratory experiments, but no reasonable product is currently available off-the-shelf. In this paper, the design and development of a very-low-cost experimental board tailored to these needs is presented. It contains both programmable prototyping circuitry based on a microcontroller and an FPGA and a set of measurement instruments, similar to the ones found on a typical lab desk, such as a digital storage oscilloscope, multimeter, analog signal generator, logic state analyzer and digital pattern generator. A first board, suitable for analog and digital electronics experiments, has been designed and manufactured, and is described in this paper. The board has been successfully used in master's degrees and PhD courses.


Subject(s)
COVID-19 , Signal Processing, Computer-Assisted , Electronics , Equipment Design , Humans , RNA, Viral , SARS-CoV-2
11.
Sensors (Basel) ; 22(10)2022 May 19.
Article in English | MEDLINE | ID: covidwho-1875743

ABSTRACT

The computation efficiency and flexibility of the accelerator hinder deep neural network (DNN) implementation in embedded applications. Although there are many publications on deep neural network (DNN) processors, there is still much room for deep optimization to further improve results. Multiple dimensions must be simultaneously considered when designing a DNN processor to reach the performance limit of the architecture, including architecture decision, flexibility, energy efficiency, and silicon cost minimization. Flexibility is defined as the ability to support as many multiple networks as possible and to easily adjust the scale. For energy efficiency, there are huge opportunities for power efficiency optimization, which involves access minimization and memory latency minimization based on on-chip memory minimization. Therefore, this work focused on low-power and low-latency data access with minimized silicon cost. This research was implemented based on an ASIP (application specific instruction set processor) in which an ISA was based on the caffe2 inference operator and the hardware design was based on a single instruction multiple data (SIMD) architecture. The scalability and system performance of our SoC extension scheme were demonstrated. The VLIW was used to execute multiple instructions in parallel. All costs for data access time were thus eliminated for the convolution layer. Finally, the processor was synthesized based on TSMC 65 nm technology with a 200 MHz clock, and the Soc extension scheme was analyzed in an experimental model. Our design was tested on several typical neural networks, achieving 196 GOPS at 200 MHz and 241 GOPS/W on the VGG16Net and AlexNet.


Subject(s)
Neural Networks, Computer , Silicon , Equipment Design , Models, Theoretical
12.
Respir Care ; 67(8): 899-905, 2022 08.
Article in English | MEDLINE | ID: covidwho-1863113

ABSTRACT

BACKGROUND: Methacholine challenge testing (MCT) is a common bronchoprovocation technique used to assess airway hyper-responsiveness. We previously demonstrated that the addition of a viral filter to the nebulizer exhalation limb substantially reduced expelled particles during MCT. Our aim was to evaluate whether this modification affects the delivered dose of methacholine. METHODS: A mechanical ventilator was connected to a lung simulator with breathing frequency 15 breaths/min, tidal volume 500 mL, inspiratory-expiratory ratio 1:1, with a sinusoidal waveform. We compared methacholine dose delivery using the Hudson Micro Mist or AeroEclipse II BAN nebulizers powered by either a dry gas source or a compressor system. A filter placed in line between the nebulizer and test lung was weighed before and after 1 min of nebulized methacholine delivery. Mean inhaled mass was measured with and without a viral filter on the exhalation limb. Dose delivery was calculated by multiplying the mean inhaled mass by the respirable fraction (particles < 5 µm) and inhalation time. Unpaired t test was used to compare methacholine dose delivery with and without viral filter placement. RESULTS: The addition of a viral filter did not significantly affect methacholine dose delivery across all devices tested. Using a 50-psi dry gas source, dose delivered with or without a viral filter did not differ with the Hudson (422.3 µg vs 282.0 µg, P = .11) or the AeroEclipse nebulizer (563.0 µg vs 657.6 µg, P = .59). Using the compressor, dose delivered with and without a viral filter did not differ with the Hudson (974.0 µg vs 868.0 µg, P = .03) or the AeroEclipse nebulizer (818.0 µg vs 628.5 µg, P = .42). CONCLUSIONS: The addition of a viral filter to the nebulizer exhalation limb did not affect methacholine dose during bronchoprovocation testing. Routine use of a viral filter should be considered to improve pulmonary function technician safety and infection control measures during the ongoing COVID-19 pandemic.


Subject(s)
COVID-19 , Exhalation , Administration, Inhalation , Aerosols , Albuterol , Bronchodilator Agents , Equipment Design , Humans , Methacholine Chloride , Nebulizers and Vaporizers , Pandemics
13.
JASA Express Lett ; 2(5): 055202, 2022 05.
Article in English | MEDLINE | ID: covidwho-1854216

ABSTRACT

Medical masks have become necessary of late because of the COVID-19 outbreak; however, they tend to attenuate the energy of speech signals and affect speech quality. Therefore, this study proposes an optical-based microphone approach to obtain speech signals from speakers' medical masks. Experimental results showed that the optical-based microphone approach achieved better performance (85.61%) than the two baseline approaches, namely, omnidirectional (24.17%) and directional microphones (31.65%), in the case of long-distance speech and background noise. The results suggest that the optical-based microphone method is a promising approach for acquiring speech from a medical mask.


Subject(s)
COVID-19 , Hearing Aids , Speech Perception , COVID-19/prevention & control , Equipment Design , Humans , Masks , Speech , Vibration
14.
Clin Oral Investig ; 26(9): 5741-5749, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-1826515

ABSTRACT

OBJECTIVES: The aim of this in vitro study was to investigate viruses' stabilities on manual toothbrushes using feline coronavirus (FeCoV) as representative of coronaviruses and an Avian influenza A virus H1N1 for influenza viruses. MATERIAL AND METHODS: Two viruses, FeCoV (Strain Munich; titer 107.5 TCID50/ml) and H1N1 (RE 230/90; titer 106.5 TCID50/ml), were used in this study. Manual toothbrushes were disassembled into bristles, bristle fixation, and back of the toothbrush head, contaminated with the viruses and air-dried for 24 h. In a second experiment, whole toothbrush heads were contaminated, rinsed with water (5 ml for 15 s) and then air-dried. RESULTS: For FeCoV, immediately after contamination, the following average titers were recovered: fixation: 106.41, back of head: 106.81 and bristles: 106.63 TCID50/ml. Following air-drying of 12 (fixation) and 24 h, titers of ≤ 102.5, 103.75, and 102.72 TCID50/ml were found in the respective groups, with a detection limit of 102.5 TCID50/ml. For H1N1, immediately after contamination, the following average titers could be recovered: fixation: 105.53, back of head: 105.97 and bristles: 105.75 TCID50/ml. Following air-drying of 8 (fixation) and 24 h, titers were ≤ 102.5, 103.63, and 103.53 TCID50/ml in the respective group, again with 102.5 TCID50/ml being the detection limit. In case of water rinse, no infectious virus could be recovered after 12 h. CONCLUSION: Viral load of both viruses is reduced by air-drying, especially following water rinsing. Clinical relevance The toothbrush itself plays an insignificant role in the self-transmission of coronavirus and influenza virus.


Subject(s)
Influenza A Virus, H1N1 Subtype , Equipment Design , Toothbrushing , Water
15.
J Natl Med Assoc ; 114(2): 121-122, 2022 04.
Article in English | MEDLINE | ID: covidwho-1814780
16.
J Mech Behav Biomed Mater ; 131: 105248, 2022 07.
Article in English | MEDLINE | ID: covidwho-1804572

ABSTRACT

The respirator as one of the personal protective equipment is essential for industrial activities (e.g., mining, painting, woodcutting, manufacturing) for protection from contaminants in the air and during the Covid-19 pandemic to protect the wearer from infection. The respirators nowadays are commonly made of rigid plastic. They are expensive, cumbersome, and not comfortable to wear. The many components with complex structures prevent it from cleaning and reusing. We develop a practical and scalable strategy to create customized respirators with durability using computational modeling and 3D printing. It is shown that by morphing the shape according to the user's photo, the respirator is designed to fit a user's face without air leaks. Using a printing-mold-casting method, this respirator can be manufactured by silicone rubber with accuracy, which is highly durable, with its mechanics primarily not affected by sterilization. These features provide the current respirator adaptivity and convenience in carrying and storing, as well as more comfort for long-time wearing.


Subject(s)
COVID-19 , Respiratory Protective Devices , COVID-19/prevention & control , Equipment Design , Humans , Pandemics/prevention & control , Printing, Three-Dimensional , Ventilators, Mechanical
17.
PLoS Negl Trop Dis ; 16(3): e0010221, 2022 03.
Article in English | MEDLINE | ID: covidwho-1793647

ABSTRACT

Low-cost improvised continuous positive airway pressure (CPAP) device is safe and efficacious in neonatal respiratory distress. There is a great necessity for similar device in adults, and this has been especially made apparent by the recent Coronavirus Disease 2019 (COVID-19) pandemic, which is unmasking the deficiencies of healthcare system in several low-resource countries. We propose a simplified and inexpensive model of improvised CPAP in adults using locally available resources including aquarium air pumps and a novel pressure release mechanism. Although the safety and efficacy of improvised CPAP in adults are not established, the conceptual model we propose has the potential to serve as a lifesaving technology in many low-resource settings during this ongoing pandemic and thus calls for expedited research.


Subject(s)
COVID-19/therapy , Continuous Positive Airway Pressure/instrumentation , Equipment Design/economics , Respiratory Therapy/instrumentation , Adult , Humans , Noninvasive Ventilation/instrumentation , SARS-CoV-2
18.
Medicine (Baltimore) ; 101(9): e28890, 2022 Mar 04.
Article in English | MEDLINE | ID: covidwho-1730757

ABSTRACT

ABSTRACT: The aim of this study was to determine which of 4 laryngoscopes, including A-LRYNGO, a newly developed channel-type video-laryngoscope with an embedded artificial intelligence-based glottis guidance system, is appropriate for tracheal intubation training in novice medical students wearing personal protective equipment (PPE).Thirty healthy senior medical school student volunteers were recruited. The participants underwent 2 tests with 4 laryngoscopes: Macintosh, McGrath, Pentax Airway-Scope and A-LRYNGO. The first test was conducted just after a lecture without any hands-on workshop. The second test was conducted after a one-on-one hands-on workshop. In each test, we measured the time required for tracheal intubation, intubation success rate, etc, and asked all participants to complete a short questionnaire.The time to completely insert the endotracheal tube with the Macintosh laryngoscope did not change significantly (P = .177), but the remaining outcomes significantly improved after the hands-on workshop (all P < .05). Despite being novice practitioners with no intubation experience and wearing PPE, the, 2 channel-type video-laryngoscopes were associated with good intubation-related performance before the hands-on workshop (all P < .001). A-LRYNGO's artificial intelligence-based glottis guidance system showed 93.1% accuracy, but 20.7% of trials were guided by the vocal folds.To prepare to manage the airway of critically ill patients during the coronavirus disease 2019 pandemic, a channel-type video-laryngoscope is appropriate for tracheal intubation training for novice practitioners wearing PPE.


Subject(s)
COVID-19/prevention & control , Intubation, Intratracheal/instrumentation , Laryngoscopes , Laryngoscopy/instrumentation , Personal Protective Equipment/adverse effects , Adult , Artificial Intelligence , Equipment Design , Female , Glottis , Humans , Male , Manikins , SARS-CoV-2 , Students, Medical
20.
J Laryngol Otol ; 136(3): 265-267, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1692720

ABSTRACT

BACKGROUND: Tracheostomy, being a high aerosol-generating procedure, poses a great challenge to surgeons, especially during the coronavirus disease 2019 pandemic. It is important to preserve staff numbers as this fight may go on for a long time. Personal protective equipment plays a key role in the protection of healthcare workers. Barrier enclosure has been attempted in procedures such as intubation and tracheostomy. The use of boxes became popularised for intubation and they have been utilised in many centres. METHODS: This paper describes the box designed by our team and presents our surgical experience with the box. The box is made of transparent acrylic. It is sealed at all ends, with a negative-pressure environment. The hand ports were designed to allow maximum manoeuvrability for surgeons, without restricting hand movements. CONCLUSION: The proposed box will provide more protection to healthcare workers during tracheostomy. However, the box is yet to be validated.


Subject(s)
COVID-19/prevention & control , COVID-19/transmission , Infection Control/instrumentation , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Tracheostomy , Adult , COVID-19/epidemiology , Equipment Design , Humans , Male
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