<var>Through a complete review of published research over the last 60 years, researchers aim to propel development of new head injury metrics forward.</var>

Metrics that help engineers design safer helmets and vehicles to prevent fatalities went mostly unchanged for about 50 years. Now, researchers are looking for better metrics to help prevent brain injuries&mdash;from mild concussions to traumatic damage.

In &ldquo;A Review of Head Injury Metrics Used in Automotive Safety and Sports Protective Equipment,&rdquo; published in the ASME Journal of Biomedical Engineering, authors Stefan Duma and Bethany Rowson examined every major metric that has been published over the past 60 years, including some of the original work done at Wayne State University in the 1960s and 1970s that examined skull fractures and were used for early football helmet and vehicle design standards. This effort summarizes existing head injury metrics and their applications for head and brain injuries.

Duma is Harry C. Wyatt Professor of Engineering and director of the Institute for Critical Technology and Applied Science (ICTAS) at Virginia Tech and Rowson is a former Virginia Tech research assistant professor. The team defined a metric as any variable or combination of variables that is &ldquo;used to assess injury severity, while a criterion is any quantitative value that is considered a threshold for injury or is assigned a predicted risk of injury.&rdquo;

The Virginia Tech team has about 30 years of history in automobile safety. About 20 years ago, they started working more in the sports and football area. Today, about 40 faculty and students at Virginia Tech work on brain-related research.
<img alt="" src="~/getmedia/03352d6a-8cb5-41f8-aedf-96603cdaf6a8/brain-img1.jpg" />
&ldquo;When you look at brain injury, a lot of the same tools are used when we evaluate vehicle safety as well as athletic player safety,&rdquo; Duma said. &ldquo;So, it made a lot of sense for us to do a detailed systematic review of brain injury criteria and head injury criteria that are used in both auto safety and sports biomechanics.&rdquo;

According to the review, the first head injury metrics to be included in safety standards were meant to reduce severe head injuries and fatalities. After the National Operating Committee on Standards for Athletic Equipment implemented football helmet standards in 1974, fatal head injuries in football dropped by approximately 74 percent, the authors noted. Similarly, with the implementation of mandatory Federal Motor Vehicle Safety Standards in 1968, the fatality rate of motor vehicle occupants dropped by 81 percent. Implementation of both standards saved thousands of lives, Duma added.

&ldquo;When we started using some of these metrics, we had a big reduction in injury rates. But there was not a lot of change for about 50 years, so it kind of stayed steady,&rdquo; he said. &ldquo;And now we&rsquo;re in a much more dynamic time where people are looking at much more complex and effective injury criteria. And the ultimate hope is that we can reduce more brain injuries.&rdquo;

Duma and Rowson noted that injury metrics are based on translational motion, rotational motion, or a combination of the two, and figuring out how to limit the amount of energy that is transferred during an event to an individual&rsquo;s head. Once metrics have been tested, evaluated, and analyzed, engineers are able to use them to better design cars and helmets that minimize injury and fatality risks.

While there have been numerous proposed brain injury metrics, the authors stated that few have been implemented in safety standards for vehicles or sports protective equipment. And those are still based off experimental data collected in the 1950s and 1960s, which was used to develop the Wayne State Tolerance Curve, which is the relationship between linear head acceleration, duration of acceleration, and incidence of head injury.
<img alt="" src="~/getmedia/358e7bd2-da97-4ca8-a6c8-620b30021700/brain-img2.jpg" />
&ldquo;If you start with reducing fatalities, which a lot of the initial work has done, now what we want to do is reduce concussions and brain injuries,&rdquo; he said. &ldquo;So, the real focus now and into the future is what metric is going to be best to help designers reduce concussion.&rdquo;

A tremendous amount of research is already underway worldwide into concussions, but &ldquo;there&rsquo;s a great deal still to be discovered in that space and a lot of questions to answer, [such as] why there are different injury rates,&rdquo; Duma said. &ldquo;This paper can help provide the foundation to examine some of these trends by using some of these different metrics.&rdquo;

But one major drawback to existing research is how limited the data is for different populations. Historically, most brain injury analysis in sports focused on male football players, Duma noted.

&ldquo;For about the past five years, we&rsquo;ve begun to focus much more on gender and sex differences in brain injury,&rdquo; he said. &ldquo;We&rsquo;ve really expanded that effort into women&rsquo;s lacrosse, rugby and soccer, really looking at understanding brain injury differences between men and women. And that&rsquo;s where a lot of the research is right now.&rdquo;

Duma and Rowson cautioned that as these new metrics are developed, they must be effectively evaluated against real world datasets without sampling bias, such as actual injury rates from a population, and head impact data from both high- and low-risk individuals.

&ldquo;The thing that I&rsquo;m really interested in is a simple question, which is how much is too much? How many times, how often, what&rsquo;s the frequency, what&rsquo;s the magnitude? We really just don&rsquo;t know [the answer to] that simple question,&rdquo; Duma explained. &ldquo;So, the idea is if we can better determine that, then we can really start to scope firm limits on head impact exposure for all sports and all activities.&rdquo;

Through a complete review of published research over the last 60 years, researchers aim to propel development of new head injury metrics forward.

<var>Through a complete review of published research over the last 60 years, researchers aim to propel development of new head injury metrics forward.</var>

Metrics that help engineers design safer helmets and vehicles to prevent fatalities went mostly unchanged for about 50 years. Now, researchers are looking for better metrics to help prevent brain injuries&mdash;from mild concussions to traumatic damage.

In &ldquo;A Review of Head Injury Metrics Used in Automotive Safety and Sports Protective Equipment,&rdquo; published in the ASME Journal of Biomedical Engineering, authors Stefan Duma and Bethany Rowson examined every major metric that has been published over the past 60 years, including some of the original work done at Wayne State University in the 1960s and 1970s that examined skull fractures and were used for early football helmet and vehicle design standards. This effort summarizes existing head injury metrics and their applications for head and brain injuries.

Duma is Harry C. Wyatt Professor of Engineering and director of the Institute for Critical Technology and Applied Science (ICTAS) at Virginia Tech and Rowson is a former Virginia Tech research assistant professor. The team defined a metric as any variable or combination of variables that is &ldquo;used to assess injury severity, while a criterion is any quantitative value that is considered a threshold for injury or is assigned a predicted risk of injury.&rdquo;

The Virginia Tech team has about 30 years of history in automobile safety. About 20 years ago, they started working more in the sports and football area. Today, about 40 faculty and students at Virginia Tech work on brain-related research.

Advancing Head Injury Metrics Research

<var>Researchers at Vanderbilt University have invented a nitrogen gas-powered thruster that is worn on the back that can correct falls as they start, restoring balance and averting potential injury.</var>

Falls can lead to severe and fatal injuries, particularly for elderly people. According to the U.S. Centers for Disease Control and Prevention, millions of people fall each year, with one in five suffering serious injury.

Michael Goldfarb, a professor of mechanical engineering at Vanderbilt University, has first-hand experience dealing with this health risk. &ldquo;As my parents grew older, both had experiences with fall risk that really limited their quality of life,&rdquo; he said. &ldquo;My father, in particular, had Parkinson&rsquo;s disease.&rdquo;

Goldfarb began thinking about new ways to correct occasional states of imbalance. Robotic exoskeletons can offer balance assistance, but have design challenges, such as having to coordinate a recovery response with the user. To avoid requiring a large frame or other structure (which would impede independence), he decided to focus on building a backpack-worn system that can apply forces directly to a person&rsquo;s body using a thruster.

&ldquo;This research challenge seemingly has not received much attention and therefore there were a lot of unknowns,&rdquo; Goldfarb said. &ldquo;Correcting a fall is a shared task between the person falling and the device helping to arrest the fall. What is the distribution of shared effort? How much force is appropriate to correct an impending fall? For how long is the force required? Can the magnitude of assistance required be provided by a compact cold-gas thruster?&rdquo;

Goldfarb and fellow researchers Almaskhan Baimyshev and Michael Finn-Henry then set out to create a lightweight, cold-gas thruster (CGT) jetpack that senses when a fall has been initiated and can provide a restoring force to help the person recover his or her balance. 
 
<img alt="" src="~/getmedia/5f7e2c63-99d6-45e1-9aef-b2ae61af4793/fall-img1.jpg" /> 
 
The prototype consists of four key features:

<ul>
	<li>Gas thruster subsystem: The compressed gas tank and converging-and-diverging nozzle use nitrogen because the non-toxic gas has a high molecular weight (which increases thrust) and is available at a low cost.</li>
</ul>
&nbsp;

<ul>
	<li>Gas valve subsystem: A custom high-throughput, fast-acting solenoid valve activates the CGT in the event of an impending fall.</li>
</ul>
&nbsp;

<ul>
	<li>Nozzle servo subsystem: A servo system controls the angle of the nozzle (and therefore the thrust vector) about the axis of rotation.</li>
</ul>
&nbsp;

<ul>
	<li>Cold-gas thruster embedded system and control hardware: The embedded system provides sensing and control of the CGT prototype, including a microcontroller and six-axis inertial measurement unit.</li>
</ul>
&nbsp;

To test the system, the team created a &ldquo;rocking block&rdquo; model as a simple approximation of a standing human. The CGT was able to restore the rocking block to its original stability when released from all initial angles well outside of its unassisted basin of stability, indicating promise as a wearable device for preventing or mitigating falls for people at fall risk.

Among the design challenges the team faced was developing a low-power, compact, very-high-throughput, fast-acting valve that can release 1,500-psi cold gas with a response time of a few milliseconds. Another challenge was detecting the onset of a fall and predicting when (and eventually in what direction) to fire the thruster to arrest the fall.

&ldquo;We also wanted to confine the sensing and actuation elements of the system to the backpack,&rdquo; said Goldfarb. &ldquo;All sensing required to make these decisions should ideally be on the backpack&mdash;for example, detection should not depend on external cameras or sensors worn on other parts of the body.&rdquo;

The CGT is a first-of-its-kind device. The team was pleasantly surprised by the control authority the thruster provides (the ability to provide substantial corrective assistance) and its soft but firm correction when arresting a fall.

&ldquo;One thing I really appreciate about it is that it combines what are sometimes considered disparate fields of mechanical engineering, including fluid mechanics, nozzle design, electropneumatic valve design, dynamics of multi-link rigid-body systems, and control theory,&rdquo; Goldfarb said. &ldquo;The work has also entailed substantial aspects of mechatronic design, particularly associated with the onboard sensing and control of the CGT.&rdquo;

The team published their results in the paper, &ldquo;Feasibility of a Wearable Cold-Gas Thruster for Fall Prevention&rdquo; in the August 2022 issue of the ASME Journal of Dynamic Systems, Measurement, and Control.
<img alt="" src="~/getmedia/2bac9e64-c06b-4fdd-b9dc-780f84efafab/fall-img2.jpg" />
<h5>Future Development</h5>

Goldfarb is currently developing a single degree-of-freedom system, which is directed at arresting backward falls.&nbsp;

&ldquo;For what it&rsquo;s worth, we were told by people who are experts in satellite thrusters that we would never be able to get the magnitude of thrust we were seeking,&rdquo; said Goldfarb. &ldquo;Our experiments proved them wrong.&rdquo;&nbsp;

The team recently tried the device on human subjects and it was effective in correcting balance. A current challenge is determining what algorithm to use for detecting an impending fall in a human. &ldquo;Much research has been conducted to detect a fall that has occurred, but almost none for how to detect an impending fall,&rdquo; said Goldfarb. &ldquo;We have enjoyed this research to date and will be delighted if our work eventually contributes to interventions that improve independence and quality of life for people who are at fall risk.&rdquo;

Researchers at Vanderbilt University have invented a nitrogen gas-powered thruster that is worn on the back that can correct falls as they start, restoring balance and averting potential injury.

<var>Researchers at Vanderbilt University have invented a nitrogen gas-powered thruster that is worn on the back that can correct falls as they start, restoring balance and averting potential injury.</var>

Falls can lead to severe and fatal injuries, particularly for elderly people. According to the U.S. Centers for Disease Control and Prevention, millions of people fall each year, with one in five suffering serious injury.

Michael Goldfarb, a professor of mechanical engineering at Vanderbilt University, has first-hand experience dealing with this health risk. &ldquo;As my parents grew older, both had experiences with fall risk that really limited their quality of life,&rdquo; he said. &ldquo;My father, in particular, had Parkinson&rsquo;s disease.&rdquo;

Goldfarb began thinking about new ways to correct occasional states of imbalance. Robotic exoskeletons can offer balance assistance, but have design challenges, such as having to coordinate a recovery response with the user. To avoid requiring a large frame or other structure (which would impede independence), he decided to focus on building a backpack-worn system that can apply forces directly to a person&rsquo;s body using a thruster.

&ldquo;This research challenge seemingly has not received much attention and therefore there were a lot of unknowns,&rdquo; Goldfarb said. &ldquo;Correcting a fall is a shared task between the person falling and the device helping to arrest the fall. What is the distribution of shared effort? How much force is appropriate to correct an impending fall? For how long is the force required? Can the magnitude of assistance required be provided by a compact cold-gas thruster?&rdquo;

Goldfarb and fellow researchers Almaskhan Baimyshev and Michael Finn-Henry then set out to create a lightweight, cold-gas thruster (CGT) jetpack that senses when a fall has been initiated and can provide a restoring force to help the person recover his or her balance.

Backpack Could Reduce the Risk of Fall

Paul P. Palies, director of the Combustion and Propulsion for Aviation Research Center at the University of Tennessee Space Institute, discusses the prospects for fueling aircraft with hydrogen.

Flying with Hydrogen

Ro-Bats, Bat-Bots, and Other Bat-like Robots

&nbsp;
<div class="infogram-embed" data-id="1b84054c-e967-4c9d-8c33-068ada31088e" data-title="Ro-Bats, Bat-Bots, and Other Bat-like Robots" data-type="interactive">&nbsp;</div>

For these engineers, the allure of biologically inspired flight still remains strong.

January-March 2023

<var>What if your car was as vulnerable to hack into as your laptop? The reality is cars today are basically a computer on wheels. According to Car and Driver, 40 percent of a new car&rsquo;s cost is driven by electronic components. The New York Times reported that a modern vehicle could contain more than 3,000 computer chips. Electronics are such an essential part of a car&rsquo;s design that the shortage of semiconductors due to supply chain disruption from the pandemic has impacted auto assembly lines worldwide, creating a lack of new vehicles on the market.</var> 
 
By introducing computer systems into vehicles, hackers have found ways to exploit their vulnerabilities. In 2015, Black Hat security researchers Charlie Miller and Chris Valasek hacked a Jeep Cherokee via its infotainment system. Miller and Valasek exploited how the vehicle autogenerated its Wi-Fi password based on the time when the car&rsquo;s multimedia system would turn on. Through the infotainment system, the hackers could manipulate the air conditioner, the radio, the windshield wipers, and even the transmission. On a road test with Wired magazine, the hackers cut the transmission as the vehicle was driving 70 mph on the highway. This past February, German teenager David Colombo identified a vulnerability in the TeslaMate, a third-party application used by Tesla owners to analyze car performance. By hacking the app, Colombo was able to unlock doors, turn on and off the headlights, and control the radio. He was even able to track in real-time the location of the car. 
 
<img alt="" src="~/getmedia/5329b926-0216-4ace-bdb7-ec2d9631e42a/cyber1@2x.jpg" /> 
<var>&ldquo;We have connected vehicles today that exposed multiple internet access points to the internet. There is the infotainment system, but also smart sensors and various devices connected to smart roads and smart cities,&rdquo; said Francesco Pascale, solution lead of embedded IIoT and device management at Almaviva Digitaltec.</var> 
 
Pascale, along with Marco Lombardi and Domenico Santaniello, professors at the Department of Industrial Engineering at the University of Salerno, recently authored a study on how cyberattacks can be detected in connected vehicles. The study &ldquo;Two-Step Algorithm to Detect Cyber-Attack Over the Can-Bus: A Preliminary Case Study in Connected Vehicles&rdquo; was published in the ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part B: Mechanical Engineering. The paper highlights how connected vehicles today receive over-the-air updates, transmit diagnostic information, and provide streaming entertainment options. These vehicle-to-everything connections make many cars vulnerable to being hacked. &ldquo;Some types of cyberattacks can be targeted to take possession of sensitive data, but the most dangerous ones, as seen in past years, can aim to compromise the car motor functions or, even worse, to take possession of it while driving. It is not difficult to think that autonomous vehicles can become attractive targets for hackers in the not-too-distant future,&rdquo; Pascale said. Last year, the European Union Agency for Cybersecurity (ENSIA) published the Cybersecurity Challenges in the Uptake of Artificial Intelligence in Autonomous Driving report, highlighting the security challenges future autonomous vehicles face and how the artificial intelligence systems can be exploited. Possible attack scenarios include tampering with the car&rsquo;s computer vision, jamming or blinding the sensors, hijacking communication channels, and information disclosure. To help identify these attacks, Pascale, Lombardi, and Santaniello propose to analyze the data flow that moves via the communication channels between various electronic control units (ECUs) inside the vehicle CAN-Bus, the internal communication system. Using a two-step algorithm that first performs a spatial-temporal analysis of the data and then a probabilistic analysis, the algorithm can understand if a given stream of data in a particular time box can be considered an attack or not with a certain probability. 
 
<img alt="" src="~/getmedia/f2df193b-96e5-44bb-a29b-ed7445863ad5/cyber2@2x.jpg" /> 
 
&ldquo;This methodology has been expanded to include the recognition of real-world scenarios, such as city traffic, driving on a motorway, extra-urban roads with animals, etc., in order to have even more precision and accuracy in the analysis,&rdquo; Pascale said. The current algorithm is part of the Italian patent n.102021000009548, soon extending internationally. The patent will become part of MinervaS, a startup organization creating solutions for vehicles and energy systems, promoted by the University of Salerno. The global market for automotive cybersecurity is expected to increase significantly over the next decade. The projected market value will reach $5.3 billion by 2026. Drivers want smart and connected cars, providing detailed information about their trips and entertainment while driving. Companies such as SafeRide and Synopsys offer cybersecurity suites that help protect vehicles from cyber threats. According to Pascale, dealing with cyberattacks is a delicate approach. &ldquo;An immediate solution could be to exclude the node that generated the attack from the system (virtually disconnect the ECU from the CAN-Bus). However, this solution is not always applicable because, at times, it could be a node belonging to a critical system such as everything concerning the mechanics of the vehicle; if the attack is carried out while driving, this would involve a risk for the health of people at the internal of the same,&rdquo; Pascale said. Another approach could be to block the vehicle to avoid possible damage automatically. However, the problem with this approach is that if the attack targets a non-critical part, blocking the car may not be warranted. According to Pascale, &ldquo;the right approach would be to consider the weight of the attack with respect to the node that is attacked and evaluate the risk associated with each and on the basis of that foresee targeted actions.&rdquo; As cars become smarter and more connected, cybersecurity will continue to play an essential role in vehicles and their safety. 
 
&nbsp;

New research from the University of Salerno provides methods on how to detect and protect connected vehicles from cyberattacks.

<var>What if your car was as vulnerable to hack into as your laptop? The reality is cars today are basically a computer on wheels. According to Car and Driver, 40 percent of a new car&rsquo;s cost is driven by electronic components. The New York Times reported that a modern vehicle could contain more than 3,000 computer chips. Electronics are such an essential part of a car&rsquo;s design that the shortage of semiconductors due to supply chain disruption from the pandemic has impacted auto assembly lines worldwide, creating a lack of new vehicles on the market.</var> 
 
By introducing computer systems into vehicles, hackers have found ways to exploit their vulnerabilities. In 2015, Black Hat security researchers Charlie Miller and Chris Valasek hacked a Jeep Cherokee via its infotainment system. Miller and Valasek exploited how the vehicle autogenerated its Wi-Fi password based on the time when the car&rsquo;s multimedia system would turn on. Through the infotainment system, the hackers could manipulate the air conditioner, the radio, the windshield wipers, and even the transmission. On a road test with Wired magazine, the hackers cut the transmission as the vehicle was driving 70 mph on the highway. This past February, German teenager David Colombo identified a vulnerability in the TeslaMate, a third-party application used by Tesla owners to analyze car performance. By hacking the app, Colombo was able to unlock doors, turn on and off the headlights, and control the radio. He was even able to track in real-time the location of the car.

Advancing Cybersecurity in Connected Vehicles

<var>Lidar, or light detection and ranging, is a popular remote sensing method used for measuring the exact distance to an object. These imaging systems are increasingly used in the development of autonomous vehicles (AVs). However, final technology implementation cannot yet be achieved because major AV manufacturers are only now starting to select providers for data collection units that can be introduced in commercial vehicles.</var>

One of the biggest unknowns in the development of AVs is how adverse weather conditions challenge the development of safe and reliable advanced autonomous systems for sensing and perception. How does the diffraction of light through rain, fog, and snow limit lidar performance? 
 
Although many AV developers are hopeful that automotive lidar sensors will be safe and effective in all weather conditions, a quantitative analysis of these effects is lacking. Currently, testing for autonomous vehicles is primarily performed in sunny environments. Testing conducted in good weather cannot be assumed to correlate directly with performance quality under extreme weather conditions, which could result in false detection caused by the backscattered intensity, thereby reducing the reliability of the sensor. Thus, the sensitivity of lidar to weather is a major drawback to commercialization. 
 
To help resolve this issue, researchers at Frostburg State University in Frostburg, Md., led by Jamil Abdo, associate professor of mechanical engineering and department chair, tested lidar sensors in adverse weather to understand how extreme weather impacts lidar performance. 
 
<img alt="" src="~/getmedia/b2a54a21-306a-4e32-ba61-9b2045095f9a/selfdriving1@2x.jpg" /> 
<var>The results were presented in &ldquo;Effective Range Assessment of Lidar Imaging Systems for Autonomous Vehicles Under Adverse Weather Conditions with Stationary Vehicles&rdquo; in ASME&rsquo;s Journal of Risk and Uncertainty in Engineering Systems.</var>

<h4>Approach and Methodology</h4>

Abdo and his team designed an experiment to evaluate lidar performance under adverse weather conditions. Data sets were recorded under these conditions to determine the effective range to estimate the maximum range at which the lidar sensors can return points. 
 
The testing set-up and algorithms were developed for two commercial lidar sensors&mdash;Velodyne VLP-32 and Ouster OS1-32. Weather resistance of the set-up was an important consideration. The weatherproof platform was designed so that the sensors units were located about three feet high off the ground. 
 
We wrote programs to interface with these lidar units and to analyze the data,&rdquo; Abdo said. &ldquo;These programs allowed us to count the number of points in a region of space.&rdquo; 
 
The team selected a remote area for testing to ensure that other cars did not drive by, affecting the data. The test was also designed to meet the goals of ease of testing and reproducibility in testing locations. 
 
&ldquo;Even though the western Maryland area around Frostburg is a great location for testing, it was very hard to have a reproducible weather condition,&rdquo; Abdo said. &ldquo;We had to use design-of-experiment techniques to account for nondesirable factors such as noise during the testing.&rdquo; 
 
Abdo decided the best way to test the lidar units was in a worst-case scenario with two cars heading directly toward each other, recreated by driving a car straight toward the test platform. &ldquo;This is the worst-case scenario for car detection as when the car faces the lidar sensor, its cross-section is the smallest with respect to the sensor,&rdquo; Abdo said. 
 
Two types of tests were performed under various weather conditions. The first involved stationary tests where the car stopped every 7.5 meters for a few seconds before driving forward another 7.5 meters. The second method conducted testing with the car moving toward the lidar units at varying speeds of five mph, 10 mph, and 20 mph. 
 
Test results showed that both dense fog and heavy rain severely impacted lidar sensors&rsquo; object detection and operating range detection. Light rain had minimal effect on lidar performance, and snow had no negative impact. 
 
<img alt="" src="~/getmedia/37843adc-af7c-457e-b410-f484b00c2f6c/selfdriving2@2x.jpg" />

<h4>Moving Forward</h4>

Determining the influence of weather on lidar sensor performance is a critical step toward improving the safety levels for autonomous driving under adverse weather conditions &ldquo;because such analyses provide reliable information for adapting vehicle behavior,&rdquo; Abdo said. 
 
The AV industry has already taken notice of Abdo&rsquo;s work. Three major lidar manufacturers have contacted Abdo since he published the team&rsquo;s research/findings in September 2021, he said. The team has also received funds from Maryland Industrial Partners (MIPS) and Intelligent Fusion Company to support the second phase of research activities. 
 
For this work, &ldquo;Lidar performance in rain, snow, fog, smog, and dust will be investigated using dynamic sensors and moving targets,&rdquo; Abdo stated. &ldquo;We also plan to explore object tracking&mdash;for example, other vehicles and any potential obstacles&mdash;with lidar systems.&rdquo;

Explore how adverse weather conditions can impact autonomous vehicles&rsquo; lidar cameras.

<var>Lidar, or light detection and ranging, is a popular remote sensing method used for measuring the exact distance to an object. These imaging systems are increasingly used in the development of autonomous vehicles (AVs). However, final technology implementation cannot yet be achieved because major AV manufacturers are only now starting to select providers for data collection units that can be introduced in commercial vehicles.</var> 
One of the biggest unknowns in the development of AVs is how adverse weather conditions challenge the development of safe and reliable advanced autonomous systems for sensing and perception. How does the diffraction of light through rain, fog, and snow limit lidar performance?

How Self-Driving Cars See in Extreme Weather

Interview with Luca Capriotti

Luca Capriotti, former president of the International Youth Nuclear Congress, shares his passion for nuclear energy and beliefs that it can become a viable, safe power source to be used globally and responsibly in the future.

The Future of Power is Nuclear

Infographic: Sodium-Cooled Fast Reactor

&nbsp;
<div class="infogram-embed" data-id="_/GNZqhKYA24E6kz9OqOfZ" data-title="Infographic-RD Pulse-v02" data-type="interactive">&nbsp;</div>

<var>Most nuclear reactors in operation today use water as a coolant, but one promising alternative looks to replace water with liquid sodium. Sodium can be heated to high temperatures before boiling, which means that a sodium-cooled reactor can operate at atmospheric pressure and can use a thinner reactor vessel. These reactors also will produce less radioactive waste. Explore the diagram of a sodium-cooled fast reactor below.</var>

Sodium-Cooled Fast Reactor

July-September 2022

<var>Using 3D scanning, 3D simulation, and CAD, engineers at the Queensland University of Technology have created a patient-specific contoured mattress that successively supports patients in the operating room.</var>
Paige Little is an expert on using state-of-the-art imaging technology to understand ideal body position and support for enhancing the quality of sleep. It&rsquo;s the kind of research used to improve beds for the home. But in 2018, Little was contacted by a consultant who asked for something more serious. Could she design a customized, patient-specific surgical mattress for a 10-year-old about to undergo spinal surgery?

The patient had Morquio syndrome, a disorder that causes skeletal abnormalities and neuromuscular scoliosis. She would need to lie safely on her stomach and the front of her body for the duration of the surgery.

&ldquo;Intraoperative patient position is always a critical factor in spinal surgery, particularly in the case of prone patient positioning, where the anatomy and physiology of the torso is such that additional pressure may have adverse effects on the cardiopulmonary system as well as causing skin and muscle necrosis,&rdquo; Little said. &ldquo;Optimal patient positioning for spine surgery is vital for surgical success and the minimization of complications intra and postoperatively.&rdquo;

Little, an associate professor at the school of mechanical, medical, and process engineering at Queensland University of Technology, is up to the challenge. Using an innovative digital workflow involving 3D surface scanning, 3D simulation and computer-aided design (CAD), she successfully created a customized theater mattress with the patient&rsquo;s specific body-contour requirements. The operation was a success, and the surgical team praised the mattress and its positive impact on patient outcome.
<img alt="" src="~/getmedia/3cd9331a-8fc6-47de-8bf9-c54a38524afa/patient-img1.jpg" /> <var>Dr Paige Little at Research Centre Qld Children&rsquo;s Hospital.</var>

<h5>Patient-specific design</h5>

Little&rsquo;s goal was to create a customized mattress to hold the patient safely and reduce possible skin damage during the surgery procedure. By using digital simulation tools and CAD, she was able to create a patient-specific surgical mattress that fit the contours of the patient&rsquo;s body. This made it easier for the surgeon to relieve load bearing on prominent anatomical features during the surgery because the support surface was tailored to the patient&rsquo;s anatomy for the lengthy procedure.

&ldquo;The design process is based in CAD, and for many of the mattresses I have designed, I use Solidworks to create the mattress contours,&rdquo; Little said. &ldquo;We have recently explored the use of CNC machining to create the surface contours in the polyurethane foam, and with high spindle speeds it is possible to machine this foam using standard tooling. The machining is very successful with well-defined surface contours, and relatively little post-process cleaning is needed to remove dust waste. The foams do not require freezing to machine them. They also do not release toxic fumes or particulate matter.&rdquo;

Topographic scanning of the entire patient was required to create a mattress contour. &ldquo;The contour is not a replica of the patient&rsquo;s anatomy, but rather is custom-designed using the topographic scan as a basis,&rdquo; Little said. &ldquo;The design process cannot be parameterized&mdash;the design is created for each patient using CAD methods to alleviate pressure on the skin surface over areas that are delicate, or regions of the anatomy that cannot bear load for long periods of time. For some corrective surgeries, the patient may be lying stationary for many hours.&rdquo;

Manufacture is currently a manual, just-in-time process. The process may benefit from CNC machining or robotic manufacturing, especially for mattress contours that are for large or tall individuals or have deep cutouts and/or overhangs.

Sealy of Australia then manufactured the final mattress product. Technicians used the 3D model to hand-cut and piece together multiple layers of soft hypo-allergenic foam to conform exactly to the patient&rsquo;s anatomy.

The custom mattress is effectively contoured to the patient&rsquo;s anterior anatomy during surgery. Intraoperative monitoring indicated the patient was not under undue cardiovascular strain over the course of the operation &ldquo;and she successfully remained in the prone position for the entire eight-hour operation,&rdquo; Little said. &ldquo;Immediately postoperatively, there was no evidence of excessive interface pressure between the patient and the support, suggesting the custom-fit mattress successfully distributed the patient&rsquo;s body weight, alleviating regions of excessive pressure.&rdquo;
<img alt="" src="~/getmedia/a3cf9bdb-f951-4224-a7dc-5c8ec7269b24/patient-img2.jpg" /><var>Sealy of Australia R&amp;D manager Daniel Green exams form that contours to the patient&rsquo;s torso.</var>

<h5>Moving Forward</h5>

Since the first use of the surgical mattress, Little has designed 11 other supportive mattresses for pediatric patients with unique anatomies requiring support during surgery&mdash;all with successful results.

The next step is to continue showcasing the mattresses to a broader clinical audience so other patients can benefit from the use of customized body supports during surgery. &ldquo;Their surgical teams will also gain confidence in reducing the risks of complications due to extended periods of weight-bearing in patients with unique conditions,&rdquo; Little said.

The digital workflow she used to design the mattresses can also be applied to the design and advanced manufacturing of other custom-fit devices to assist in treatment and/or rehabilitation of patients. &ldquo;These same techniques&mdash;3D topographic scanning, 3D simulation, and CAD methods&mdash;can be applied to the design of customized corrective/rehabilitation orthoses,&rdquo; Little said, &ldquo;or to the custom design of supports for radiation therapy to ensure the patient is positioned in a repeatable position between treatment appointments.&rdquo;

Using 3D scanning, 3D simulation, and CAD, engineers at the Queensland University of Technology have created a patient-specific contoured mattress that successively supports patients in the operating room.

<var>Using 3D scanning, 3D simulation, and CAD, engineers at the Queensland University of Technology have created a patient-specific contoured mattress that successively supports patients in the operating room.</var>

Paige Little is an expert on using state-of-the-art imaging technology to understand ideal body position and support for enhancing the quality of sleep. It&rsquo;s the kind of research used to improve beds for the home. But in 2018, Little was contacted by a consultant who asked for something more serious. Could she design a customized, patient-specific surgical mattress for a 10-year-old about to undergo spinal surgery?

The patient had Morquio syndrome, a disorder that causes skeletal abnormalities and neuromuscular scoliosis. She would need to lie safely on her stomach and the front of her body for the duration of the surgery.

&ldquo;Intraoperative patient position is always a critical factor in spinal surgery, particularly in the case of prone patient positioning, where the anatomy and physiology of the torso is such that additional pressure may have adverse effects on the cardiopulmonary system as well as causing skin and muscle necrosis,&rdquo; Little said. &ldquo;Optimal patient positioning for spine surgery is vital for surgical success and the minimization of complications intra and postoperatively.&rdquo;
Little, an associate professor at the school of mechanical, medical, and process engineering at Queensland University of Technology, is up to the challenge. Using an innovative digital workflow involving 3D surface scanning, 3D simulation and computer-aided design (CAD), she successfully created a customized theater mattress with the patient&rsquo;s specific body-contour requirements. The operation was a success, and the surgical team praised the mattress and its positive impact on patient outcome.

Patient Support Via Customized Surgical Mattresses

<var>Hydrogen seems like an ideal fuel, but a feasibility analysis reveals the factors that will determine its success.</var>
Hydrogen has the highest energy density by weight of any fuel. So it only makes sense that compressed hydrogen gas is being considered as a carbon-free replacement for diesel in heavy-duty trucks. A hydrogen-fueled truck fleet would substantially reduce greenhouse gas emissions and other pollutants from the freight industry.

Before that can happen, engineers need to work out the optimum technology to make hydrogen economical as well as clean.

​&ldquo;Hydrogen technology is currently expensive because of relatively low deployment. Once it is more common, the refueling infrastructure cost should decrease significantly. Hydrogen refueling infrastructure can be implemented immediately. It has the potential to be very economical,&rdquo; said Wahiba Yaici, a research scientist at the CanmetENERGY Research Centre, Natural Resources Canada in Ottawa, Ontario.

The cost of hydrogen itself looms as the main element in the acceptance of compressed hydrogen. It is rarely found isolated and must go through processes to extract it. Each hydrogen production method involves separating hydrogen from some compound. Common extraction processes include natural gas reforming, biomass gasification, and coal gasification. So-called green hydrogen is produced by using renewable energy such as solar and wind to power the electrolysis of water or other hydrogen-making reactions.
<img alt="A truck cab with visible hydrogen fuel tank" src="~/getmedia/c92a71b0-061d-466a-b7d5-8b3ffeabf1ff/hydrogen-img1.jpg" /><var>Generally, green hydrogen is more expensive than hydrogen produced by other methods, but it also has the advantage of producing zero carbon emissions.</var>

Storing hydrogen is another issue. Hydrogen at a fueling station can be stored either as a gas or a liquid. Storing hydrogen as a gas typically requires high-pressure tanks at 5,000 to 10,000 psi. Storage as a liquid requires cryogenic temperatures, as the boiling point of hydrogen at one atmosphere pressure is &minus;252.8 &deg;C (-423 &deg;F).

The main options for onboard hydrogen storage in vehicles are gaseous storage at 5,000 psi or at 10,000 psi in thermally insulated tanks or in materials with superior chemical properties, like metal hydrides or organic compounds,&rdquo; Yaici said.

To address the hydrogen refueling scenario for big trucks, Yaici teamed with Michela Longo, an associate professor at the Politecnico di Milano in Italy, to write a paper, &ldquo;Hydrogen Gas Refueling Infrastructure for Heavy-Duty Trucks: A Feasibility Analysis,&rdquo; for the ASME Journal of Energy Resources Technology. Both authors are mechanical engineers. The pair chose to pursue hydrogen because it can be used as fuel in modified internal combustion engines (ICEs), reducing the need to purchase new vehicles. Existing diesel engines can easily be modified to burn hydrogen. This is in contrast to the fuel-cell-powered vehicles most people think of when talking hydrogen; fuel cells combine hydrogen and oxygen, yielding water, heat, and electricity used to power an electric motor that drives the vehicle.

This paper investigates the feasibility of developing a nationwide network of hydrogen refueling infrastructure to help convert the long-haul, heavy-duty (LHHD) truck fleet from diesel fuel to hydrogen. Diesel is currently the main fuel used to transport freight over the road.

The team carried out a technical analysis to estimate the number of hydrogen refueling stations needed to convert the fleet of LHHD vehicles to hydrogen. They also did an economic analysis to evaluate the final selling price of hydrogen.

According to Yaici, &ldquo;Results from the techno-economic study showed that hydrogen prices can vary significantly.&rdquo; On average, they found hydrogen to cost 239 percent more than diesel due to the diverse costs of the various production methods for hydrogen. Hydrogen also has about 2.6 times the energy density of diesel fuel by weight, which serves as an equalizer. Energy density by volume is another matter because at the operating temperature of trucks, diesel is a liquid while hydrogen is a gas, giving it a lower energy density by volume if it is not liquefied by cryogenics. Regardless of the hydrogen production method, the process can occur at a central facility or locally where it is needed.

&ldquo;A central system can increase the scope of production by producing hydrogen at large facilities that take advantage of bulk processes to reduce costs per unit,&rdquo; Yaici said. &ldquo;Nevertheless, hydrogen must be transported to its destination via pipeline or trucks. This will increase the operational fees. A distributed process, one where hydrogen is produced on demand locally, eliminates the need to deliver hydrogen over long distances.&rdquo;
<img alt="A hydrogen &quot;gas&quot; pump accompanied by a small array of solar panels" src="~/getmedia/7f96ca95-97e5-4062-9f56-5da4b3d880e5/hydrogen-img2.jpg" />
Hydrogen stations are built to refuel vehicles in similar manner to those used by diesel stations. Each refueling station will consist of a compressor, storage tanks, and at least one dispenser. Yaici pointed out the versatility of the feasibility study. &ldquo;The methodology and models proposed can be used for studying the techno-economics of hydrogen refueling stations in any country and for other types of ICE fleets or fuel cell vehicles,&rdquo; he said.

This includes refueling stations for vehicle fleets powered by renewable fuels such as renewable natural gas or biofuels. Engineering analyses such as this one will help shape the future of transportation.

Hydrogen seems like an ideal fuel, but a feasibility analysis reveals the factors that will determine its success.

<var>Hydrogen seems like an ideal fuel, but a feasibility analysis reveals the factors that will determine its success.</var>
Hydrogen has the highest energy density by weight of any fuel. So it only makes sense that compressed hydrogen gas is being considered as a carbon-free replacement for diesel in heavy-duty trucks. A hydrogen-fueled truck fleet would substantially reduce greenhouse gas emissions and other pollutants from the freight industry.

Before that can happen, engineers need to work out the optimum technology to make hydrogen economical as well as clean.

Putting Hydrogen to the Economic Test

Interview with Moncef Krarti

Moncef Krarti, head of the Building System Program at the University of Colorado, Boulder, discusses ways to turn down the temperature on hot, overcrowded urban areas.

Cooling Cities by Combating Heat Islands

Infographic: Pneumatic Help for Grasping

<div class="infogram-embed" data-id="_/JNK9h2xLuaalwUNVZqrN" data-title="Pneumatically-Powered Help for Grasping" data-type="interactive">&nbsp;</div>
 
&nbsp;

Researchers hope this pneumatic grip glove could soon help relieve industrial workers of some pain.

Workers who must repeat forceful actions with their hands&mdash;whether operating industrial hand tools or typing on a keyboard&mdash;are often subject to carpal tunnel syndrome and other cumulative trauma disorders, which not only are painful but also diminish grip strength. Naveen Chandrashekar, a professor of mechanical and mechatronics engineering at the University of Waterloo in Ontario, and graduate student Daniel Loewen, now chief technology officer at ioAirFlow in Winnipeg, looked for a way to reduce the force needed by workers operating hand tools, which would lean to less wear and tear on the hands and wrists.

January-March 2023

In This Issue

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Advancing Head Injury Metrics Research

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Backpack Could Reduce the Risk of Fall

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Q & A

Flying with Hydrogen

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Ro-Bats, Bat-Bots, and Other Bat-like Robots

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