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Covid-19 update: 02 July 2020

02 Jul 2020

A round-up of this week's coronavirus-related news and countermeasures from the photonics industry.

Currently, there are no specific guidelines on the most effective materials and designs for facemasks to minimize the spread of droplets from coughs or sneezes to mitigate the transmission of Covid-19. While there have been prior studies on how medical-grade masks perform, data on cloth-based coverings used by the vast majority of the general public are sparse.

Using flow visualization of emulated coughs and sneezes, researchers at Florida Atlantic University’s College of Engineering & Computer Science (FAU) assessed the efficacy of facemasks in obstructing droplets. One of the group’s conclusions is that “loosely folded facemasks and bandana-style coverings provide minimal stopping-capability for the smallest aerosolized respiratory droplets.”

Research from FAU, just published in the journal Physics of Fluids, demonstrates through visualization of emulated coughs and sneezes, a method to assess the effectiveness of facemasks in obstructing droplets.

Laser light sheet

The researchers employed flow visualization in a laboratory setting using a laser light sheet and a mixture of distilled water and glycerin to generate the synthetic fog that made up the content of a cough-jet. They visualized droplets expelled from a mannequin’s mouth while simulating coughing and sneezing. They tested masks that are readily available to the general public, which do not draw away from the supply of medical-grade masks and respirators for healthcare workers.

Results showed that loosely folded facemasks and bandana-style coverings stop aerosolized respiratory droplets to some degree. However, well-fitted homemade masks with multiple layers of quilting fabric, and off-the-shelf cone style masks, proved to be the most effective in reducing droplet dispersal. These masks were able to limit the speed and range of the respiratory jets significantly, albeit with some leakage through the mask material and from small gaps along the edges.

Significantly, uncovered emulated coughs were able to travel noticeably farther than the currently recommended 6ft / 2m distancing guideline. Without a mask, droplets traveled more than 8 feet; with a bandana, they traveled 3 ft7in / 1.1m; with a folded cotton handkerchief, they traveled 1ft3iin / 0.4m; with the stitched quilted cotton mask, they traveled 2.5in / 0.1m; and with the cone-style mask, droplets traveled about 8in / 0.2m.

“In addition to providing an initial indication of the effectiveness of protective equipment, the visuals used in our study can help convey to the general public the rationale behind social-distancing guidelines and recommendations for using facemasks,” said Siddhartha Verma, Ph.D., lead author and an assistant professor who co-authored the paper with Manhar Dhanak, Ph.D., department chair, professor, and director of SeaTech; and John Frakenfeld, technical paraprofessional, all within FAU’s Department of Ocean and Mechanical Engineering.

When the mannequin was not fitted with a mask, they projected droplets much farther than the 6ft /2m distancing guidelines currently recommended by the United States Centers for Disease Control and Prevention. The researchers observed droplets traveling up to 12ft / 3.7m within approximately 50s.

“We found that although the unobstructed turbulent jets were observed to travel up to 12 feet, a large majority of the ejected droplets fell to the ground by this point,” said Dhanak. “Importantly, both the number and concentration of the droplets will decrease with increasing distance, which is the fundamental rationale behind social-distancing. Promoting widespread awareness of effective preventive measures is crucial at this time as we are observing significant spikes in cases of Covid-19 infections in many states, especially Florida.”

'Space-enabled' Covid-19 tests

So-called “space-enabled” Covid-19 tests are underway in Italy to empower healthcare workers, civil protection volunteers and members of the emergency services to help other people safely. As the immediate crisis caused by the coronavirus pandemic fades in Europe, system developer the European Space Agency (ESA) says “extensive testing systems are needed to enable the vital economic recovery.”

An ESA-backed mobile field laboratory set up at Piedmont is enabling the Italian authorities to test thousands of key workers for Covid-19. Some of the tests carried out there now take just a few minutes, instead of a few hours. Staff use the lab to perform and analyze nasopharyngeal swabs to identify whether or not a person has the coronavirus, as well as to conduct antibody tests to demonstrate whether a person who has been infected has an immune response to the virus. Key workers who have a negative antibody test or a positive antibody test followed by a negative swab can then return to work quickly, supporting the economic recovery.

Jean-Luc Gala, director of the Centre for Applied Molecular Technologies at the Université Catholique de Louvain (UCLouvain) in Belgium, developed the lab and is operating it in Piedmont. “In this lab, we can do also molecular testing, to see if the virus is present in patients and to analyze the immunity as well,” he said. “This is the type of quick answer that we can provide very rapidly.”

Called B-LiFE, short for “a biological light fieldable laboratory for emergencies”, the system comprises: tents for the laboratory and command-and-control units; specialized equipment to rapidly analyze samples; an information and management system to collect and store all the results; and dedicated satellite communication systems for reliable and secure communication.

Earth observation

Roland Gueubel, B-LiFE director at UCLouvain, commented, “The satellite telecommunications are crucial for the autonomy of the B-LiFE laboratory, for logistics support and for the real-time data transfer to health authorities. Furthermore, Earth observation imagery is a key resource for mapping the crisis area, for situational awareness tools, for the geolocation of sampling and for real-time epidemiological mapping.”

Arnaud Runge, medical engineer overseeing the mission at ESA, added, “B-LiFE has demonstrated that it can bring solutions to crisis situations anywhere in the world, in a very fast and reliable way. Any country could make use of B-LiFE – if you trigger requests, Europe will be able to offer an answer.”

B-LiFE is certified under the EU’s civil protection mechanism, which aims to enable national authorities to exchange information to identify best practice and work interchangeably in the field when disaster strikes. It was developed as part of ESA’s Space Solutions program, which provides funding and business support to hasten the development of new products and services that use space assets.

Lighting group Signify together with the US National Emerging Infectious Diseases Laboratories (NEIDL) at Boston University, MA, US, have conducted research that validates the effectiveness of Signify’s UV-C light sources on the deactivation of SARS-CoV-2, the virus that causes Covid-19.

Since the start of the pandemic, Dr. Anthony Griffiths, Associate Professor of Microbiology at Boston University School of Medicine and his team have been working on developing tools to support scientific advancement in this field.

During their research the team has treated inoculated material with different doses of UV-C radiation coming from a Signify light source and assessed the inactivation capacity under various conditions. The team applied a dose of 5mJ/cm2, resulting in a reduction of the SARS-CoV-2 virus of 99% in 6s. Based on the data, it was determined that a dose of 22mJ/cm2 will result in a reduction of 99.9999% in 25s.

Dr. Griffiths commented, “Our test results show that above a specific dose of UV-C radiation, viruses were completely inactivated: in a matter of seconds we could no longer detect any virus. We’re very excited about these findings and hope that this will accelerate the development of products that can help limit the spread of Covid-19.”

Signify supplies a range of UV-C light sources and has been working in UV technology for more than 35 years. It has a proven track record of innovation in UV-C lighting, which is designed, manufactured and installed in line with the highest safety standards. Eric Rondolat, CEO of Signify, added, “I’m very happy about the fruitful cooperation with Boston University in the fight against the coronavirus. The university has validated the effectiveness of our light sources as a preventive measure for companies and institutions as they seek ways to provide virus-free environments.”

Photonics-based Covid-19 test

Covid-19 screening can soon be conducted directly at various testing stations, and patients can get their test results in about an hour from the time they get a nasal swab.

A team of researchers at NUS, Singapore, has developed a portable Covid-19 micro-PCR diagnostic system, called Epidax, which enables rapid and accurate on-site screening of infectious diseases and significantly reduces the time required to analyse patient samples. The viral nucleic acid detection, which uses an LED light driven system yields results within one hour.

Conventional polymerase chain reaction testing currently being used for Covid-19 diagnosis has to be carried out in specialised testing facilities, and takes a few hours or a few days for results to be made known. A 10-member team from the NUS Institute for Health Innovation & Technology (iHealthtech), led by Director Professor Lim Chwee Teck, has developed a novel diagnostic system from scratch in a record time of two months.

“Until a vaccine against the coronavirus becomes available, ramping up testing is a critical first step to curb the spread of Covid-19 and to provide appropriate medical care for those tested positive. If we can quickly detect the coronavirus, we can better contain it. Epidax provides an effective solution to address these limitations,” said Prof Lim.

Epidax, which is a microfluidics-based PCR diagnostic system, uses a specially designed microfluidic chip that comprises micro-channels where samples are processed. By employing microfluidic technology, the system is able to process a smaller amount of sample for quicker detection of Covid-19 infection.

Organizations worldwide are using thermal cameras and have applied this methodology to screen people entering and leaving certain premises, says camera developer Thermavis. This approach is a quick, non-contact method that is safe for both the camera operator and the people being screened, reducing the risk of the spread of Covid-19.

Thermavis is a division of Transputec, based in Wembley, London, UK, which is focused on providing thermal vision solutions for the detection and controlled access of people using a blend of innovative technology combined with AI based software.

Thermavis thermal cameras are sensitive devices capable of measuring small temperature differences. The technology has been tuned to be most sensitive and accurate to the range of human body temperatures, from 36°C (96.8°F) to 42°C (107.6°F). Thermavis cameras display a subject’s temperature visually, and can be set to sound alarms that alert when a certain temperature threshold is exceeded.

The handheld and individual cameras can record and store the thermal data of subjects, for audit or regulatory purposes. Thermavis has solutions designed for rapidly screening large number of people as well as screening on an individual basis.

Quanergy Systems, a developer of LiDAR sensors and smart perception solutions, has announced the first commercial integration of 3D AI-powered LiDAR solutions with Genetec’s Security Center unified security platform. The integrated solutions will provide “advanced people flow and occupancy management in smart spaces as well as enhanced threat detection and surveillance in high-security environments.

In relation to the ongoing pandemic, target applications include restricted security areas, passenger flow analytics, and occupancy management to help automate security, people counting and social distancing applications. Enzo Signore, CMO at Quanergy, commented, “Our integration with the Genetec platform enables a unique level of automation of many applications across retail, critical infrastructure, airport, seaport, enterprise, and smart cities.”

David Lenot, Airport Product Leader at Genetec, added, “By bringing their 3D LiDAR sensor data into the traffic and passenger flow modules in our unified platform, we’re helping airports and other organizations address pressing needs while also unlocking new insights into their security operations.”

LaCroix Precision OpticsABTechCHROMA TECHNOLOGY CORP.Universe Kogaku America Inc.LASEROPTIK GmbHMad City Labs, Inc.SPECTROGON AB
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