HAMNET Report 4th October 2020

Amateur Radio Emergency Service (ARES) operators participated in the annual nationwide American Radio Relay League’s Simulated Emergency Test yesterday.

During the exercise, ARES groups established emergency communications to various locations throughout the counties to provide situation reports related to simulated emergencies in their states.

Voice and data communications were used by the ARES members with their portable ham radios and laptops on battery power. The annual Simulated Emergency Test exercise confirms the ability for ham radio operators to provide emergency communications to Emergency Operations Centres, the Emergency Management Agency State Operations Centres and across the counties and states during any disaster. The highly trained ARES groups volunteer their time, skills and equipment to support the citizens of their counties and Directors with the Offices of Homeland Security/Emergency Management during all types of emergencies.

Now GDACS reports that large wildfires continue to burn across California, having killed 26 people, and destroyed more than 7900 buildings. 80000 people have been evacuated to safety as of 29th September, and there were 22 separate active fires in California, covering an area of 931000 hectares. The fire danger forecast remains “extreme” over most of central and south-western USA, including California.

GDACS is also reporting an earthquake of magnitude 6.4 close to the Tonga Islands on 1st October, seriously disturbing 2000 people on the islands. No tsunami warning was issued. And in Bangladesh, heavy rains continue to affect Northern Bangladesh, resulting in overflowing rivers and triggering flooding. 125000 people have been affected, hundreds of buildings damaged, and many roads flooded. Forecasts for further heavy rain and thunderstorms have been issued.

When someone is buried by an avalanche, earthquake or other disaster, a rapid rescue can make the difference between life and death. The Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR has developed a new kind of mobile radar device that can search hectare-sized areas quickly and thoroughly. The new technology combines greater mobility with accurate detection of vital signs.

Some regions of the world record hundreds of earth tremors a day. Most of these are of a minor nature—but occasionally an earthquake of such destructive power strikes that it destroys buildings and triggers tsunamis that lay waste to huge areas. Faced with this kind of disaster, rescue crews often struggle to locate and dig out injured people quickly enough to save them. Although radar devices can provide useful assistance, current systems are limited to stationary operation. Set up in a fixed spot, they can only search up to a distance of twenty to thirty metres, depending on the radar specifications. In disasters involving large-scale destruction, this distance is simply too short.

Based in Wachtberg, Germany, Fraunhofer FHR offers a technology that aims to significantly increase the search radius. “What we’ve developed is a mobile radar system that locates people buried under rubble by detecting their pulse and breathing,” says Reinhold Herschel, a team leader at Fraunhofer FHR. “Our longer-term goal is to mount this radar device on a drone and fly it over the disaster site. This would make searches faster and more effective even in areas extending over hectares.”

In basic terms, the radar device works by emitting waves. Part of each wave is reflected by the debris, but some of the wave passes through the rubble and is reflected by people and anything else buried underneath it. The distance to an object is calculated by measuring how long the signal takes to return to the detector in the radar system. If that object is moving—even if it is just a buried person’s skin rising and falling by a few hundred micrometres with each heartbeat—this changes the phase of the signal. The same applies to the tiny movements caused by their breathing. People typically take a breath no more than 10 to 12 times a minute, while the heart beats an average of 60 times a minute, so it is relatively simple to distinguish between these different signal changes using algorithms. The researchers can also determine exactly where the buried person is located.

This is made possible by a special type of radar known as MIMO, which stands for multiple-input, multiple-output. MIMO radars use multiple transmitters and receivers to set up different “vantage points” which can then be used to identify the exact location where paramedics should dig for survivors.

What is unique about this technology is its combination of mobility and accurate detection of people’s vital signs. The mobility advantage generally refers to examples such as mounting the device on a drone and flying it over the disaster site, but it is also possible to turn this principle on its head. Set up the system in a fixed spot, for example, and it can be used to detect the vital signs of people moving around close to the radar. There are a number of situations where this could be useful, such as providing first aid to large numbers of casualties in a sports hall following an earthquake. In this case, the radar device could be used to record vital signs and assign them to each individual to determine who is in most urgent need of assistance. In this example, the algorithm focuses primarily on detecting changes such as whether someone’s heart is beating irregularly or a patient is breathing very rapidly. The radar system can distinguish the individual signals and display them separately. Accuracy is also high, with the device measuring pulse rates with 99 percent accuracy as compared to readings taken using portable heart rate monitors. More research is still needed on using the radar to find people buried under rubble, but researchers have already made significant progress in detecting vital signs close to the stationary radar system, successfully putting it to the test at distances of up to 15 meters.

Finally, a major roadblock to large scale testing for coronavirus infection in the developing world is a shortage of key chemicals, or reagents, needed for the test, specifically the ones used to extract the virus’s genetic material, or RNA.

A method of testing for the COVID-19 virus that doesn’t make use of these chemicals but still delivers an accurate result has been developed, paving the way for inexpensive, widely available testing in both developing countries and industrialized nations, where reagent supplies may again be in short supply.

The method for the test, published October the 2nd in PLOS Biology, omits the step in the widely used reverse transcription polymerase chain reaction (RT-PCR) test where the scarce reagents are needed.

The accuracy of the new test was evaluated using 215 COVID-19 samples that RT-PCR tests had shown were positive, with a range of viral loads, and 30 that were negative.

It correctly identified 92% of the positive samples and 100% of the negatives. The positive tests not detected had very low levels of virus protein.

Thank you to Medical Xpress for this excerpt from their report.

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.