Bicycle Helmet Impact Sensors: Revolutionizing Rider Safety or Overrated Technology

Are bicycle helmet impact sensors truly effective in detecting concussions. How do these devices work and what are their limitations. Can impact sensors accurately measure the force experienced by a rider’s head during a crash. What do experts say about the reliability of helmet-mounted impact sensors. Is investing in an impact sensor for your bicycle helmet worth it.

The Rise of Bicycle Helmet Impact Sensors: A Closer Look

In recent years, the cycling world has seen a surge in the development and marketing of impact sensors designed to be attached to bicycle helmets. These devices, primarily accelerometers, aim to detect and measure the force of impacts during crashes or collisions. However, the effectiveness and reliability of these sensors have been subjects of debate among experts in the field of helmet safety and concussion research.

Impact sensors for helmets gained prominence around 2005 when they were first introduced for football players. Since then, numerous companies have entered the market, offering various devices claiming to enhance rider safety. But do these sensors live up to their promises? Let’s delve deeper into the world of bicycle helmet impact sensors to understand their potential benefits and limitations.

How Do Bicycle Helmet Impact Sensors Work?

Bicycle helmet impact sensors typically utilize accelerometers to measure the force of an impact. These devices are designed to be attached to the helmet’s exterior or integrated into its structure. When a significant impact occurs, the sensor registers the force and provides some form of alert or data readout.

Most commercially available sensors use one to three accelerometers to capture impact data. However, experts argue that this may not be sufficient for accurate measurements. To capture the full spectrum of forces involved in an impact, a minimum of seven accelerometers, oriented in different planes, would be necessary. For even greater accuracy, eleven accelerometers would be ideal.

Types of Impact Sensors

• Single-accelerometer devices
• Multi-accelerometer systems
• Helmet-mounted sensors
• Mouthguard-integrated sensors

While helmet-mounted sensors are the most common, some researchers have explored alternative placement options, such as mouthguard-integrated sensors. These aim to measure forces closer to the head itself, potentially providing more accurate data.

The Limitations of Helmet-Mounted Impact Sensors

Despite their popularity, helmet-mounted impact sensors face several significant limitations that call into question their effectiveness in accurately assessing the risk of concussion or head injury.

Measuring Helmet Impact vs. Head Impact

One of the primary concerns with helmet-mounted sensors is that they measure the force experienced by the helmet itself, not the force transmitted to the rider’s head. This discrepancy is crucial because the helmet’s primary function is to absorb and dissipate impact energy.

As a result, the force recorded by the sensor on the helmet’s exterior can be significantly higher than what the rider’s head actually experiences. This disparity can lead to false alarms or, more concerningly, a failure to detect potentially concussive impacts that may not register as severe on the helmet’s surface.

Limited Directional Sensitivity

Most commercially available impact sensors use only one or three accelerometers. This limited number of sensors can only measure forces in specific directions, potentially missing crucial data from impacts occurring at different angles.

To capture a comprehensive picture of an impact’s force and direction, experts recommend using a minimum of seven accelerometers oriented in various planes. Some researchers even suggest that eleven accelerometers would provide optimal accuracy.

The Complexity of Concussion Diagnosis

While impact sensors can provide valuable data on the forces involved in a crash or collision, it’s important to understand that they cannot diagnose concussions on their own. The relationship between impact force and concussion risk is complex and not fully understood by medical professionals.

Variability in Concussion Thresholds

Research has shown that there is no universal threshold for concussive impacts. Some athletes have experienced peak forces of 140 g’s without sustaining a clinically diagnosable injury, while others have suffered concussions from impacts below 80 g’s. This variability makes it challenging to establish definitive guidelines for concussion risk based solely on impact force measurements.

Multiple Factors Influencing Concussion Risk

The likelihood of sustaining a concussion depends on various factors beyond just the peak force of an impact. These include:

• Direction of the impact
• Area of impact on the head
• Rotational forces
• Individual physiology and susceptibility
• Previous history of concussions

Impact sensors, particularly those mounted on helmets, cannot account for all these factors, limiting their ability to accurately predict concussion risk.

Expert Opinions on Bicycle Helmet Impact Sensors

The scientific and medical communities have expressed mixed views on the effectiveness and reliability of bicycle helmet impact sensors. While some see potential benefits in certain applications, many experts urge caution in relying too heavily on these devices for concussion detection or helmet damage assessment.

FDA Warning

In April 2019, the U.S. Food and Drug Administration (FDA) issued a warning to the public regarding the use of medical devices marketed to consumers for assessing, diagnosing, or managing head injuries, including concussions and traumatic brain injuries (TBI). This warning underscores the limitations of current technology in accurately diagnosing concussions and highlights the importance of seeking professional medical evaluation following a head impact.

Research Perspectives

Researchers studying impact sensors, such as the Simbex HIT system used in football, have gathered extensive data on head impacts. However, they have found that correlating impact data with concussion occurrence remains challenging. While these systems can alert coaches to players experiencing numerous hard hits, they cannot definitively diagnose concussions or predict their likelihood based solely on impact force.

Potential Applications of Impact Sensors in Cycling

Despite their limitations, bicycle helmet impact sensors may still have valuable applications in certain contexts. Understanding these potential uses can help cyclists and teams make informed decisions about incorporating this technology into their safety protocols.

Tracking Cumulative Impact Exposure

One promising application of impact sensors is in tracking cumulative impact exposure over time. This data could be particularly useful for professional cyclists or those who frequently participate in high-risk cycling disciplines. By monitoring the number and intensity of impacts a rider experiences, coaches and medical professionals can better assess potential risks and adjust training or racing strategies accordingly.

Identifying High-Risk Behaviors

Impact sensors can help identify patterns of high-risk behavior or situations that lead to frequent impacts. This information can be used to develop targeted training programs or make course adjustments in racing scenarios to reduce the likelihood of crashes and collisions.

Research and Development

The data collected by impact sensors can contribute to ongoing research in helmet design and safety standards. By analyzing real-world impact data, manufacturers and researchers can work towards developing more effective protective gear and refining safety guidelines for cyclists.

Alternative Approaches to Assessing Helmet Damage

While impact sensors aim to provide objective data on crash forces, many experts still advocate for traditional methods of assessing helmet damage. These approaches focus on visual inspection and physical examination of the helmet following a crash or impact.

Visual Inspection Techniques

Experienced helmet technicians and safety experts recommend a thorough visual inspection of a helmet after any significant impact. This process involves carefully examining the helmet’s exterior and interior for signs of damage, such as:

• Cracks or deformations in the outer shell
• Compressed or crushed foam liner
• Separation between the shell and liner
• Damage to straps or retention systems

While this method requires some expertise to identify subtle signs of damage, it remains one of the most reliable ways to assess a helmet’s integrity after a crash.

Measuring Foam Crush

Another effective technique for evaluating helmet damage involves measuring the thickness of the foam liner at various points. By comparing these measurements to the original specifications, technicians can determine if the foam has been permanently compressed or damaged during an impact.

This method can reveal internal damage that may not be visible from the exterior, providing a more comprehensive assessment of the helmet’s protective capabilities.

The Future of Bicycle Helmet Safety Technology

As research in the field of head injury prevention continues to advance, we can expect to see further developments in bicycle helmet safety technology. While current impact sensors have limitations, ongoing studies and technological innovations may lead to more accurate and reliable systems in the future.

Integrated Sensor Networks

Future helmet designs may incorporate more comprehensive sensor networks, combining multiple types of sensors to provide a more holistic view of impact forces and head movement during a crash. These integrated systems could potentially overcome some of the limitations of current single-sensor designs.

Machine Learning and AI Applications

As more data is collected from impact sensors and clinical concussion research, machine learning algorithms and artificial intelligence could play a role in improving the accuracy of impact analysis. These technologies may help identify subtle patterns or combinations of factors that are more predictive of concussion risk than simple force measurements alone.

Personalized Risk Assessment

Advancements in biomedical research may eventually lead to more personalized approaches to concussion risk assessment. By combining impact sensor data with individual physiological factors and medical history, future systems could provide more accurate and tailored risk evaluations for each rider.

In conclusion, while bicycle helmet impact sensors represent an intriguing development in cycling safety technology, their current limitations and the complexity of concussion diagnosis necessitate a cautious approach to their use and interpretation. As research progresses and technology evolves, we may see more effective and reliable systems emerge. In the meantime, cyclists should continue to prioritize proper helmet fit, regular inspections, and prompt medical evaluation following any significant head impact.

Bicycle Helmet Impact Sensors

Impact Sensors for Helmets

Summary: Many brands of impact sensors are being sold to be added to helmets to detect hard impacts. They have limited usefulness for bicycle helmets, and limited accuracy at best. Most measure blows to the helmet, not the g’s the head inside experienced after the helmet’s energy management. The biggest risk is that they will fail to signal a concussive event or fail to signal damage to the helmet. Researchers believe they can signal hard impacts but can not diagnose concussions. They are primarily useful in multi-impact sports for tracking sub-concussive blows.

You should read this cautionary announcement from the FDA “warning the public not to use medical devices marketed to consumers that claim to help assess, diagnose or manage head injury, including concussion, traumatic brain injury (TBI) or mild TBI. “

Impact sensors (usually accelerometers) attached to football players’ heads made news about 2005, and devices to attach to helmets have been marketed by a number of companies since.

A sensor attached to a helmet can only record the g’s that the helmet sees, not what the head inside experienced. Since the helmet is managing the energy, there will be a huge difference, with the head seeing far less shock. The original Simbex HIT system for football players mounts an array of accelerometers against the player’s head, not on the outside shell of the helmet.

Accelerometers are linear, registering g’s in only one direction. To capture all of the energy in an impact, seven is the minimum number of accelerometers to use, oriented in different planes. Eleven would be more accurate. Most of the devices marketed now use only one accelerometer, or at most three.

The Simbex product uses multiple accelerometers held against the head, and gathers the data on the sidelines of a game through a wireless connection. It works, and can alert the coach when a player takes a very hard hit. Simbex and the college football researchers using the system have gathered millions of hits in their data collecting. But correlating the hits and concussions has proven elusive. There is still no agreement on the exact profile of a concussive hit. Some players have experienced 140 peak g’s without an injury that can be diagnosed clinically. Some have been concussed at levels below 80 g’s. Results vary depending on the direction of the blow, area of the impact and other factors. There is no precise way yet to define the characteristics of the hit that produces a concussion. Peak g has to be important, and rotational energy is believed to be another key element. Even a straight linear hit involves some rotational component. But what is happening inside the head as the brain moves, as different brain components with different densities and placement move in different ways, contributes to the nerve and blood vessel strain that is thought to be a big determinant of concussion. Simbex says their system is best used by coaches to identify players who are experiencing many hard hits and permit the coach to train that player to avoid them in the future.

Back in 2006 we bought some samples of a device called the Shok-SpotR and asked experts for an evaluation. The device is designed to be added to a hard shell helmet, and registers g’s above a certain level by turning a spot red. We got mixed feedback from the lab techs and other experts, who saw it as a device to register helmet damage, since it did not register g’s to the head. Some felt that even assuming it functioned correctly, the spot might not change in some crashes that would damage the helmet. Most believed that visual inspection and measuring for foam crush after a crash is the best way to determine if a helmet has been damaged. But since many consumers are not experienced in looking at damaged helmets and may not recognize damage under a shell, there may still be a place for this product if you wear a helmet with a rigid hard shell. Our samples were $25 plus shipping, from a supplier we found with Google.

As concern about concussions has grown in recent years other devices have come on the market, including Impact Alert, Shockbox, the Stabilizer First Alert (attaches to a hockey face mask) and many others. There are also sensors with electronics in a mouth guard. Those at least try to measure g’s to the head, not the helmet, but must assume that the jaw remains firmly clamped on the mouthguard through the impact sequence. We found all of those and more with this Google search. It will be more current than any list we post here would be. We know nothing of the effectiveness of any of the devices except the Simbex HIT system, a reliable indicator of hits on a sports field.

In April of 2019 the US Food and Drug Administration (FDA) issued a press release”warning the public not to use medical devices marketed to consumers that claim to help assess, diagnose or manage head injury, including concussion, traumatic brain injury (TBI) or mild TBI. ” The only devices the FDA has cleared must be used by a health care professional, and “there are currently no devices to aid in assessing concussion that should be used by consumers on their own.” That is expert advice that none of us should ignore.

This mid-2018 post on the web by child athlete advocate Brooke de Lench represents a good review of the sensor field, except that it does not distinguish between sensors mounted on a helmet and those mounted against the head. She does make the point well that the sensors are primarily useful in multi-impact sports for tracking sub-concussive blows, not for diagnosing a concussive impact.

In 2016 the F08.53 Helmet and Headgear subcommittee of ASTM began developing a standard for the performance of sensors used to track head impacts. CPSC chairs the task group. The task group will have a difficult job, and the development of the standard may take some time. There has not been much progress as of late-2020. But eventually you may be able to buy an impact device with confidence that it meets a performance standard.

Bottom line: many of the sensors are designed for use with hard shell helmets. Most will not tell you much about how hard an impact your brain actually took or whether an injury has occurred. We do not know of a consumer product that will tell you if you have a concussion, and for bike riders a medical diagnosis of the symptoms you are experiencing will always be your best indicator. If you are crashing repeatedly and need to track the number of hits your helmet experiences, there are products to do that.

Football helmet sensors monitor impact of collisions, tackles

The problem of concussions in football players arising from helmet-to-helmet collisions is receiving attention on a number of levels. According to an article in the Hendersonville Lightning, high schools in Hendersonville, North Carolina, are outfitting helmets with sensors that measure the G-force of hits on the field, in an effort to gauge the impact of collisions or tackles and flag possible concussions.

With donations from the Pardee Hospital Foundation, all four of the Hendersonville public high school football teams have helmets that a few athletes playing the more vulnerable positions will wear this season. According to the Hendersonville Lightning report, North Henderson has 12 sensor-equipped helmets and West Henderson, East Henderson and Hendersonville have four each.

“Our goal was to get 12 for each school,” Karen Yagerhofer, of the Pardee Foundation, was quoted as saying. The helmets cost $500 each, compared to $300 for regular helmets. Pardee Hospital Foundation raised $8,600 in its cornhole tournament and used the proceeds to buy helmets. 

The dime-sized sensors are fitted within the helmets and measures the G-force of hits on the field. The program’s proponents hope this information can help warn of potentially damaging hits. According to the article, an objective cognition test is used to complement what can be a subjective opinion on whether the player has a concussion.

The program is connected to the leading research program in the country into football concussions. The program has been used by the NCAA and the NFL to establish concussion treatment policies.

Dwayne Durham, director of Pardee’s sports medicine program, said in the report that the helmets neither prevent nor diagnose a concussion, but they can be valuable in alerting athletic trainers to high-impact hits that could result in a concussion.

“We’re going to be using this for data collection because what it does is whenever a player receives a hit the athletic trainer will have this sensor that is actually programmed to that helmet and it will tell us how many G-forces. It doesn’t mean the kid has a concussion, but if it rings the buzzer, we’re going the stop kids from playing just to make sure they’re OK.”

Pardee added that any hit over 90 G-force can potentially cause injury to the brain leading to a concussion, and early detection is critical to better treatment.  “If they’re OK, we let ‘em go back,” he said. “If they’re not OK, they’re subject to a five-day treatment program.”

Jim Sosebee, the head football coach at Hendersonville High School, said in the report he’s glad the school will be able to test the extra protection. “If players take a big hit “we can check on them using the tracker that reads the G-force. I’m guessing some of the biggest hits will be when they hit the ground.”

RELATED:

Vibration meter measures frequencies to 4800 Hz

New Smart Helmet Could Spot Concussions in Real Time

David Butler II / USA TODAY Sports

This fall, tens of thousands of American football players, from grade-schoolers on up to the pros, will be treated for concussions. Experts suspect that for every player who is pulled from a game and diagnosed, another will have his or her injury go unnoticed, since only those who report feeling ill or display the most conspicuous signs of traumatic brain injury — such as losing consciousness or acting disoriented — are likely to be examined by a neurologist.

In order to detect concussions as they occur, and to help coaches determine quickly and conclusively when players should be taken off the field, a team of Columbia researchers is developing what would be the first wearable diagnostic device for traumatic brain injury. Called the NoMo, the device incorporates electroencephalography (EEG) sensors of the type commonly used in hospitals to measure a patient’s brain activity. The sensors, which would ordinarily be taped to the scalp, are instead tucked in between the pads of a football helmet. Upon detecting the distinct electromagnetic wave patterns of a traumatic brain injury, they will send an alert to a computer on the sidelines.

“Within seconds of a player being hit, everyone will know whether or not he’s suffered a concussion,” says James Noble ’08PH, a Columbia neurologist who designed the technology with Columbia biomedical engineer Barclay Morrison. “This will eliminate a lot of the problems you have now with coaches, athletic trainers, and team physicians having to make fairly subjective judgments about who should be removed from a game to receive a full neurological evaluation. ”

The idea for the NoMo was inspired by Noble’s experiences serving as a neurological consultant to collegiate and professional football teams. In that role, he helps the teams’ doctors determine if and when players who have been benched for concussions are fully recovered and battle-ready again. This is a critical decision, since a player who returns to the field and takes additional hits too soon after suffering a concussion is more likely to incur long-term neurological damage.

“Everybody involved in football wants a more reliable way of identifying when these injuries happen,” Noble says. “The culture of the game, at any level, is such that the players are often reluctant to volunteer that they’re hurt. Plus, the symptoms of a concussion can be subtle and hard to spot.” 

Over the past decade, several other research teams have attempted to create wearable devices to detect concussions. Some have developed accelerometers that, when implanted in football helmets, measure the physical intensity of hits that players endure. The jostling of a player’s helmet has proved to be an imperfect proxy for concussions, though, and the NFL, after initially planning to use such devices in the 2016 season, ultimately shelved the idea.

EEG sensors inside a football helmet can detect concussions in real time. Photo courtesy of NoMo Diagnostics.

“One problem with accelerometers is that a concussion may result from an accumulation of hits rather than from one big one,” says Noble. “Our device is more reliable because it monitors the brain’s actual physiological activity in response to these hits. It will provide a real medical diagnosis.”

Noble and Morrison conducted a preliminary test of the NoMo at a Columbia football practice last year. They found that it successfully recorded the players’ brain waves, but that it must be made smaller to fit comfortably into a helmet. They are currently working on a new version of the device.

Eventually, they say, the NoMo could be adapted for use in a number of contact sports, including hockey, wrestling, lacrosse, and, if the sensors can be made small enough to slip into a headband, soccer and basketball. Furthermore, they say, the device could be inserted into military helmets to detect when soldiers suffer concussions, either from being knocked off their feet or from enduring the shock waves caused by explosions.

“The beauty of our design is that it doesn’t matter what causes the concussion,” says Morrison. “If you experience a traumatic brain injury, a red light will go off on a computer and tell someone you need help.”

RF Wireless Vendors and Resources

About RF Wireless World

The RF Wireless World website is a home of RF and Wireless Vendors and Resources.
The site covers articles, tutorials, vendors, terminology, source code (VHDL, Verilog, MATLAB,Labview), test and measurement,
calculators, news, books, downloads and more.

The RF Wireless World site covers resources on various topics such as RF, wireless, vsat, satellite, radar, fiber optics, microwave, wimax, wlan, zigbee,
LTE, 5G NR, GSM, GPRS, GPS, WCDMA, UMTS, TDSCDMA, bluetooth, Lightwave RF, z-wave, Internet of Things(IoT), M2M, Ethernet etc.
These resources are based on IEEE and 3GPP standards.It also has academic section which covers colleges and universities in engineering and MBA disciplines.

Articles on IoT based Systems

IoT based Fall detection system for elderly: The article covers architecture of the Fall detection system used for elderly people.
It mentions benefits or advantages of IoT Fall detection system.
Read More➤

Also refer other articles on IoT based systems as follows:

• AirCraft Lavatory Cleanliness System
• Collision Impact Measuring System
• Perishable Food and Vegetables Tracking System
• Driver Assistance System
• Smart Retail System
• Water Quality monitoring System
• Smart Grid System
• Zigbee based Smart Lighting System
• Zigbee based smart parking system
• LoRaWAN based smart parking system

RF Wireless Articles

This Articles section covers articles on Physical layer(PHY), MAC layer, protocol stack and network architecture based on WLAN, WiMAX, zigbee, GSM, GPRS, TD-SCDMA, LTE, 5G NR, VSAT, Gigabit ethernet based IEEE/3GPP etc. standards.
It also covers test and measurement related articles on compliance testing used for device RF/PHY conformance tests. REFER ARTICLES INDEX >>.

5G NR physical layer: The physical layer processing for 5G NR PDSCH channel and 5G NR PUSCH channel have been covered stepwise.
This 5G physical layer description is as per 3GPP physical layer specifications.

Read More➤

Repeater basics and repeater types:
It explains functions of different types of repeaters used in wireless technologies.
Read More➤

Fading basics and types: This article covers small scale fading, large scale fading, slow fading, fast fading etc. used in wireless communication are explained.
Read More➤

5G Cell Phone architecture: This article covers 5G Cell Phone Block diagram with internal modules of 5G
Cellular phone architecture.
Read More➤

Interference basics and Interference types: This article covers adjacent channel Interference, co-channel Interference,
EM Interference, ICI, ISI, light Interference, Sound Interference etc.
Read More➤

5G NR Section

This section covers 5G NR (New Radio) features, numerology, bands, architecture, deployment, protocol stack (PHY, MAC, RLC, PDCP, RRC) etc.
5G NR Quick reference Index >>

• 5G NR Mini Slot  
• 5G NR Bandwidth Part  
• 5G NR CORESET  
• 5G NR DCI Formats  
• 5G NR UCI  
• 5G NR slot formats  
• 5G NR RRC IEs  
• 5G NR SSB, SS, PBCH  
• 5G NR PRACH  
• 5G NR PDCCH  
• 5G NR PUCCH  
• 5G NR Reference Signals  
• 5G NR m-Sequence  
• 5G NR Gold Sequence  
• 5G NR Zadoff Chu Sequence  
• 5G NR Physical layer  
• 5G NR MAC layer  
• 5G NR RLC layer  
• 5G NR PDCP layer

Wireless Technology tutorials

This section covers RF and Wireless tutorials. It covers tutorials on topics such as
cellular communication, WLAN (11ac, 11ad) , wimax, bluetooth, zigbee, zwave, LTE, DSP, GSM, GPRS,
GPS, UMTS, CDMA, UWB, RFID, radar, VSAT, satellite, wlan, waveguide, antenna, femtocell, test and measurements, IoT etc.
Refer TUTORIALS INDEX >>

5G tutorial-This 5G tutorial also covers following sub topics on the 5G technology:
5G basics tutorial  
Frequency Bands  
millimeter wave tutorial  
5G mm wave frame  
5G mm wave channel sounding  
4G Vs 5G  
5G test equipments  
5G network architecture  
5G NR network interfaces  
channel sounding  
Channel types  
5G FDD vs TDD  
5G NR network slicing  
What is 5G NR  
5G NR deployment modes  
What is 5G TF  

This GSM tutorial covers GSM basics, network architecture, network elements, system specifications, applications,
GSM burst types, GSM frame structure or frame hierarchy, logical channels, physical channels,
GSM physical layer or speech processing, GSM mobile phone network entry or call setup or Power ON procedure,
MO call, MT call, VAMOS, AMR, MSK, GMSK modulation, physical layer, protocol stack, mobile phone basics,
RF planning, PS call downlink and PS call uplink.

➤Read more.

LTE Tutorial covering LTE system architecture covering LTE EUTRAN and LTE Evolved Packet Core(EPC) basics.
It provides link to LTE system overview, LTE air interface, LTE terminology, LTE UE categories, LTE frame structure, LTE physical layer,
LTE protocol stack, LTE channels (logical, transport, physical), LTE throughput, LTE carrier aggregation, Voice Over LTE, LTE advanced,
LTE vendors and LTE vs LTE advanced.➤Read more.

RF Technology Stuff

This page of RF wireless world covers step by step design of RF frequency converter with example of 70 MHz to C band RF UP converter
for microstrip board using discrete RF components viz. Mixers, Local oscillator, MMICs, synthesizer, OCXO reference oscillator,
attenuator pads. ➤Read more.

➤RF Transceiver Design & Development   
➤RF Filter design   
➤VSAT System   
➤Types & basics of microstrip   
➤Waveguide basics   

Test and Measurement Section

This section covers T&M resources, test and measurement equipments for testing DUTs based on
WLAN, WiMAX, Zigbee, Bluetooth, GSM, UMTS, LTE standards.
Test and Measurement INDEX >>

➤PXI system for T&M.
➤Signal generation and analysis 
➤PHY layer measurements 
➤WiMAX device conformance test 
➤Zigbee conformance test 
➤LTE UE conformance test 
➤TD-SCDMA conformance test

Fiber Optic Technology

Fiber optic component basics including detector, optical coupler, isolator, circulator, switches, amplifier,
filter, equalizer, multiplexer, connectors, de-multiplexer etc. This components are used in fiber optic communication.
Optical Components INDEX >>

➤Fiber optic communication tutorial 
➤APS in SDH 
➤SONET basics 
➤SDH Frame structure 
➤SONET vs SDH

RF Wireless Vendors, Manufacturers

RF Wireless World site covers manufacturers and vendors of various Rf components, systems and subsystems for vivid applications,
refer Vendors INDEX >>.

RF Component vendors covering rf isolator, rf circulator, rf mixer, rf amplifier, rf adapter, rf connector, rf modulator, rf transceiver, PLL, VCO, synthesizer, Antenna, oscillator, power divider, power combiner, filter, attenuator, diplexer, duplexer, chip resistor, chip capacitor, chip inductor, coupler, EMC stuff, RF Design Software, dielectric material, diode etc.
RF Components Vendors >>

➤LTE Base station 
➤RF Circulator 
➤RF Isolator 
➤Crystal oscillator 

MATLAB, Labview, Embedded Source codes

The RF Wireless World’s source code section covers MATLAB, VHDL, VERILOG and LABVIEW Programming languages related codes.
These codes are useful for beginners in these languages.
REFER SOURCE CODE INDEX >>

➤3 to 8 decoder VHDL code 
➤Scrambler descrambler MATLAB code 
➤32 bit ALU Verilog code 
➤T,D,JK,SR flipflop labview codes

*General public health information*

Do these five simple things to help stop coronavirus (COVID-19).

DO THE FIVE

1. HANDS: Wash them often

2. ELBOW: Cough into it

3. FACE: Don’t touch it

4. FEET: Stay more than 3ft (1m) apart

5. FEEL: Sick? Stay home

Use Contact Tracing Technology >> , Follow social distancing >> guidelines and
install data surveillance system >>
to save hundreds of lives.
Use of Telemedicine concept has become very popular in
countries such as USA and China to stop the spread of COVID-19 as it is contagious disease.

RF Wireless Calculators and converters

The calculators and converters section covers RF calculators, wireless calculators as well as unit converters.
These covers wireless technologies such as GSM, UMTS, LTE, 5G NR etc.
REFER CALCULATORS Index >>.

➤5G NR Throughput calculator  
➤5G NR ARFCN vs frequency conversion  
➤LoRa Data Rate Calculator 
➤LTE EARFCN to Frequency conversion 
➤Yagi Antenna Calculator 
➤5G NR sampling time calculator

IoT-Internet of Things Wireless Technologies

The section on IoT covers Internet of Things wireless technologies such as WLAN, WiMAX, Zigbee, Z-wave, UMTS, LTE, GSM, GPRS, THREAD, EnOcean, LoRa, SIGFOX, WHDI, Ethernet,
6LoWPAN, RF4CE, Bluetooth, Bluetooth Low Power(BLE), NFC, RFID, INSTEON, X10, KNX, ANT+, Wavenis, Dash7, HomePlug and more.
It also covers IoT sensors, IoT components and IoT companies.

Refer IoT main page>> and following links.

➤THREAD   
➤EnOcean   
➤LoRa tutorial  
➤SIGFOX tutorial  
➤WHDI   
➤6LoWPAN  
➤Zigbee RF4CE  
➤NFC  
➤Lonworks  
➤CEBus  
➤UPB  

RELATED POSTS

RF Wireless Tutorials

Different types of sensors

Share this page

Translate this page

Impact Sensors: Brain Sentry | MomsTeam

In addition to being field tested by MomsTEAM during the 2013 football season by the Newcastle (OK) High School football team, the Brain Sentry Impact Sensor is currently endorsed or mandated by over 25 leagues, schools and other organizations representing over 100,000 athletes.

For 2014 the Brain Sentry sensors are the required for participants in several football, lacrosse and hockey programs ranging from youth to the pros including the following:

• Arena Football League (AFL)
• U. S. Army All American Bowl
• Eastbay Youth All American Bowl 
• FBU National Championship 
• Indiana Football Coaches Association Grange All-Star Classic
• Baltimore Touchdown Club High School Senior All-Star Game

Why Brain Sentry for contact sports?

Athletes don’t want to be pulled off the field. They hide symptoms of concussion. They might not even know they have one, and knowing is critical because many catastrophic brain injuries are the result of second impacts to already concussed athletes. Brain Sentry monitors impacts and helps identify athletes that should be assessed for concussion. Brain Sentry helps coaches identify players with techniques that include excessive head/helmet contact. 

The Brain Sentry Impact Counter^TM is calibrated to alert when the helmet experiences rapid acceleration or deceleration. It is not a diagnostic device. Concussions and other brain injuries can occur at levels that will not trigger an alert. Do not depend on these sensors as a sole screening method for possible injury. Ignoring this warning may lead to serious or fatal brain injury.

How it works

• Price: Brain Sentry provides its sensors as an annual subscription. First year is $75 and subsequent years are $55. The sensor is guaranteed to last the full year without any battery charging.
• Install: Easy peel-and-stick application to the back of the helmet
• Easy: They sensor is motion activated – turning itself on and off to conserve power – there is no on/off switch
• Impact Counter: Brain Sentry Impact Counter Plus^TM has a display that shows the number of head impacts for the day, the week, and the year and the number of alert level hits for the year
• Alert indicator: If an athlete experiences an unusually hard hit to the head a bright red light provides an indication that the player should be assessed for injury.

Brain Sentry took significant efforts in designing a system that accurately measures appropriate impact forces, is affordable, is safe, and does not burden coaches and team staff that run youth sports leagues. There is nothing to maintain. Batteries don’t require recharging. There is nothing to remember to turn on or off. Brain Sentry sensors just work all season. Period.

At the beginning of the season simply activate the sensor and peel and stick it to the back of each helmet. The sophisitcated battery life management system allows the sensor to never need to be turned on or off. The battery never needs to be charged or changed. The sensor is fully sealed and waterproof. At the end of the season it can be simply removed and returned to Brain Sentry for recycling.

Understanding concussions: Testing head-impact sensors

James Eckner, assistant professor of Physical Medicine and Rehabilitation poses in a Michigan football helmet as he gets ready to test helmet collision on a crash test dummy. Researchers in the Biomechanics Research Lab in the Department of Mechanical Engineering test new sensors that are designed to tell players and their coaches how hard they’re hit. Such information can help in concussion diagnosis. Photo by Marcin Szczepanski, Michigan EngineeringANN ARBOR—The head of a crash-test dummy wore a football helmet as it hung upside down on a laboratory drop tower.

Dr. James Eckner stood on a ladder next to it holding its tether. He counted to five and let go.

The bust smacked into another just like it three feet below—with about the force of two linemen colliding at the start of a play.

How hard was the hit? Where was it centered? And what reactions did it cause in the defensive dummy head? Sensors sent answers to a laptop across the room.

It’ll take weeks for the researchers to analyze the data from several days of drops—part of an effort in the University of Michigan’s Biomechanics Research Lab to help improve understanding of how the head and brain react to impacts. It’s a ripe field, as the sports and science communities are becoming aware of the devastating long-term effects that decades’ worth of concussions and head hits can have on players.

“There’s a growing number of athletes that seem to be affected by these later on in life,” said Eckner, assistant professor of physical medicine and rehabilitation at the U-M Medical School. “But most athletes don’t seem to have these problems as they age, and so the tricky thing is to figure out what is causing this in one athlete, but not in another.”

Chronic traumatic encephalopathy, a progressive and degenerative disease that involves early-onset dementia, depression and trouble controlling impulses, has been found in the autopsied brains of more than 50 former NFL players. The league has agreed to a hefty settlement with thousands of former players who say officials hid the dangers.

This U-M experiment won’t immediately address the question of why some exhibit symptoms down the road and others don’t, but the researchers are laying groundwork for finding the answer. They’re comparing two high-profile head-impact monitoring systems—Riddell’s Head Impact Telemetry System (HITS) and the newer X2 Biosystems’ X-Patch. Their goal is to see if the readings match up so researchers can better interpret the data the newer system provides.

“There are a lot of papers written using the HITS, but there really aren’t papers written yet that use the X-Patch system. When they start to be written, we want to make sure we’re comparing apples to apples,” Eckner said.

The trouble is, the helmet’s not firmly attached to the head. It can slide. James Ashton-Miller

Neither system purports to be a concussion catch-all, but they can serve as another set of eyes to alert coaches and trainers to potentially harmful hits. HITS, developed in 2002, studs a football helmet with a handful of accelerometers that measure motion in a straight line. It can say where a blow falls and measure how fast the head accelerates as a collision pushes and twists it. It gets at the twist indirectly with an algorithm that uses the accelerometer data. X-Patch is a fingertip-sized device worn behind the ear.

It also uses accelerometers to measure linear motion, but tracks rotation speed more directly with a gyroscope similar to the ones that help iPhones calculate their orientations. In recent years, researchers have come to suspect that head rotation may play an important role in concussions and so this direct measurement could prove valuable.

Because the X-Patch is applied right on the skin, the researchers say it could offer athletes more versatility and give the research community a clearer picture of how the head moves in space.

“The trouble is, the helmet’s not firmly attached to the head. It can slide,” said James Ashton-Miller, research professor of biomedical engineering and mechanical engineering and director of the Biomechanics Lab. “So you get slippage between the helmet and the head, making it more difficult to predict how the brain moves inside the skull.”

In the U-M experiments, the stationary dummy wore both systems, and it contained sensors of its own for another point of comparison. The team mimicked a variety of impacts that could happen during a football game—hits from the front, back and side, and from different heights to simulate different impact velocities.

“The smaller impacts would have been on the order of linemen coming out of their stance and colliding with each other,” Eckner said. “The bigger ones would have been more like the ones that make the crowd go ‘ooh’ and ‘ahh’ during a football game—when two players running really fast collide with each other.”

I think the ultimate goal is still that one could predict which hits are going to cause concussions based on the biomechanics of the impact. James Eckne

By helping to identify more concussions—more points when players should be sidelined for a game or even a season—tools like these stand to make football and other sports safer when coupled with trained experts, the researchers say. They might also be used to keep track of wallops over a player’s career and raise flags as they rack up. And more immediately, they could help researchers test whether wearing certain equipment or strengthening particular muscles could help players protect themselves.

Using the sensors, Ashton-Miller, Eckner and their colleagues on the Michigan NeuroSport team in kinesiology and neurology are studying differences in head impact exposure in men’s and women’s ice hockey. And they’re doing some of the first studies on how neck strength influences head motion after collisions in young people.

“I think the ultimate goal is still that one could predict which hits are going to cause concussions based on the biomechanics of the impact,” Eckner said. “We’re a long way away from that goal, but it would be the greatest benefit that these systems could provide to help players, coaches, team doctors and athletic trainers.”

Related Link:

Michigan Engineering:
The University of Michigan College of Engineering is ranked among the top engineering schools in the country. At more than $130 million annually, its engineering research budget is one of largest of any public university. Michigan Engineering is home to 11 academic departments and a National Science Foundation Engineering Research Center. The college plays a leading role in the Michigan Memorial Phoenix Energy Institute and hosts the world class Lurie Nanofabrication Facility. Michigan Engineering’s premier scholarship, international scale and multidisciplinary scope combine to create The Michigan Difference. Find out more at http://www.engin.umich.edu/.

The Future of Impact and Concussion Monitoring

This four-part series examines the NFL’s $60 million investment in the Engineering Roadmap to develop research and technology to make football safer. Part one discusses the data behind the controversial helmet rule. Part two outlines the engineering work supporting the roadmap. Part three discusses the crowdsourcing of innovative solutions. This part looks at the future of the program and a new data collection device.

The University of Virginia football team’s season-opening 42-13 victory over Richmond seemed like just an unremarkable rout of a much smaller program. Hidden from public view, however, was something quite noteworthy: at least two-dozen Virginia players were wearing a new sensor technology embedded in their mouthguards that had been developed by NFL-commissioned engineers.

When the NFL allocated $60 million to its Engineering Roadmap of health and safety initiatives in 2016, the league selected the leaders of Virginia’s Center for Applied Biomechanics to head the effort. The center’s director, Jeff Crandall, and his deputy, Richard Kent, have overseen that research from their Biocore consulting lab in Charlottesville.

Previous efforts to monitor head impacts focused primarily on sensors built into helmets, but tests of those systems showed that the head often moves differently than an exterior shell. Mouthguards are preferable because the upper jaw is part of the skull. The league has tested a number of commercial and research sensor-laden mouthguards, but Biocore has also developed its own version under the stewardship of senior research scientist Nate Dau. If the pilot test with Virginia goes well, the goal will be to provide the mouthguards to NFL players on a handful of teams on a limited basis in 2019.

“We’ve been focusing heavily on the technology,” Crandall said. “What we’ve done is invested into a new technology that has very high accuracy, very small, fits into a package into a mouthguard. It’s much smaller than what was available on the market. It’s a completely new line of sensor technology.”

Few specifics are available about the device or the trial. Crandall said the Biocore product uses minimal power, is of minimal size, and was built in coordination with a sensor partner and a boutique electronics partner. He added that the device was custom-built to measure head kinematics during typical NFL impacts and that there has been significant feedback from the NFLPA about the size and fit.

The league will spend this college football season monitoring the performance of the technology before deciding on its future. NFLPA consultant Kristy Arbogast, who is also the director of engineering for the Center for Injury Research and Prevention at The Children’s Hospital of Philadelphia, has consulted closely with Biocore on the project and said there have been three points of emphasis: data accuracy, minimal intrusion into an NFL team’s routines and workflow; and comfort and usability for the players. (“I can design the most accurate sensor in the world,” she said, “but if I can’t get a player to wear it, I won’t have advanced anything.”)

Accurate and more granular data is needed to quantify the impact forces on the field, and is critical for the NFL to improve player safety and reverse the trend of concussions—which reached a record high in 2017. Crandall has said there is a goal of introducing position-specific helmets to protect against the particular types of collisions each player typically endures.

“That will really tell us on each and every play the types and severities of impacts that players at a given position are experiencing,” Crandall said, “and really help us convert that information into a helmet that’s really tuned at a position-specific level.”

All NFL players wear Zebra athlete tracking chips in their shoulder pads, recording location and velocity, but there are no impact sensors on the field of play. The league and the NFLPA are collaborating closely on mouthguard development because it would provide the best data source yet to understand hits. In conjunction with the Engineering Roadmap’s forensic video reviews and other tests using crash-test dummies, the NFL will release that information to spur innovation.

“The outcome of that is going to be a level of detail and specificity that’s going to help an entrepreneur come up with an idea that’s going to address a specific problem,” said NFL EVP of health and safety Jeff Miller.

Prevent Biometrics’ mouthguard uses four accelerometers to quantify head impacts. (Courtesy of Prevent Biometrics)

The NFL has not disclosed the results of its evaluation of the previously developed mouthguard sensors. Crandall said those products’ maturity and experience are beneficial for evaluation as his team pursues a parallel path. One of those mouthguards is produced by Prevent Biometrics. Its device will be available to thousands of high school and college football players this fall, according to chief science officer Adam Bartsch. He said Prevent continues to prove out its product as the company builds a robust system to support data collection and instant analysis. Prevent has begun syncing video footage with real-time hit data for evaluations.

“What everyone’s working on fundamentally is just trying to monitor the impacts that are worth monitoring and getting trustworthy information as fast as possible,” Bartsch said, adding later: “After one creates a gadget that you do some lab testing on, the challenge is then to build a system that can actually handle all that data and do it fast enough for all the clinicians.”

To further support the advancement of new ideas, the Engineering Roadmap had four finite element models of different helmet designs built. These complex digital models are a helpful tool for early-stage computer simulation testing of innovations. That in itself was a major undertaking, with each of four universities tasked with one helmet apiece.

“A lot of the design evolution of helmets has been, I guess I would call it, ad hoc,” Kent said. “Try something and see how it works, and it’s not very systematic. What you end up getting is very complex geometries and complex materials, like foams that are interacting with plastics.”

Finite element model of the Xenith X2E helmet created by the University of Waterloo in Ontario. (Courtesy of the NFL)

The process of shepherding an idea from initial concept through prototype, testing, and development to commercial viability can take three to six years. The NFL hopes the supply of data from all sources can expedite that process.

“Importantly though, too, as we provide that community the tools and data, their designs and their products are going to become more sophisticated,” Miller said. “They’re going to become more representative of things that can protect against specific events, which is the goal. You may see some level of acceleration there because you’re going to have a more specific target for them to shoot at.”

Other avenues of head impact screenings are in development as well. In February, the FDA approved its first concussion-related blood test. Banyan Biomarkers can test for two protein biomarkers that can eliminate the need for a costly and time-consuming CT Scan. Baynan and Quanterix, both former GE Head Health Challenge grant recipients, have begun partnering on some tests, and Quanterix CEO Kevin Hrusovsky believes his company’s technology will offer enough detail to one day make a more definitive concussion test—perhaps even on a sideline.

Earlier this year, Quanterix released a benchtop instrument that is more compact and portable than its signature wardrobe-sized Simoa machine. Hrusovsky said the process of taking blood and analyzing the specimen for the biomarkers that are indicative of a concussion currently takes about 10 minutes. But he sees a clear path to expediency by producing dedicated machines that hone in on particular biomarkers. “We probably can get this down to a few minutes,” he said.

The ultimate goal of all of this research and data collection is protecting player health. Whether monitoring for dangerous impacts through a mouthguard sensor or screening for a possible concussion via a blood test, the aim is to find ways to decrease the risk and seriousness of head injuries.

“The real question ultimately becomes,” Hrusovsky said, “‘How can a test of our objectivity get further involved and integrated into various sports to try to help protect the safety of others? What does the test do to the culture of the game when it provides a more objective measure of whether or not someone’s brain needs rest?’”

NFL commissioner Roger Goodell pledged that the league will “let science lead the way.” At some point, science will produce results. Then, the onus will be on the sport to heed them.

90,000 Motocross vs. Downhill – Which Helmet is Safer?

There is a general perception among many gravity riders that a motocross helmet is safer than a full face bike. On the surface it looks like it is reasonable. Motocross helmets are larger and heavier than full mtb, they have more material between your head and the ground when dropped, which is good, right?

– Downhill and motocross helmets look similar, but they have key differences.

Unfortunately, not everything is so simple. There is an ongoing debate in the motocross industry about how stiff a helmet should be to provide maximum protection. A number of critics point out that many helmets, especially helmets made to meet the stringent SNELL certification requirements, are designed to be so stiff that they offer less protection in most typical falls.

Which test is better?

To understand why the motorcycle helmet controversy worries cyclists, one must realize that helmets are designed for the conditions they will encounter in testing. A typical test procedure for a motorcycle helmet is to simulate accidents that can occur on the road. Testers in laboratories methodically drop helmets onto objects of various shapes from significant heights.

This intense impact makes sense given the kinetic energy with which the rider’s head strikes the road surface or car at typical highway speeds.

Testing used by the SNELL Memorial Foundation (an independent motorcycle helmet certifying group for decades) includes an even harsher helmet than the standard Department of Transportation (DOT) testing that a helmet must pass to be marketed in the United States. The latest SNELL certification standard (M2010) requires the helmet to transmit less than 275 g of overload to the dummy head inside the helmet in any part of testing involving very strong impacts on the helmet.

– Helmet testing at Moelfre Hall. Aaron Hilton breaks the rule: the bike must be on the bottom. Photo by Turnip Towers.

Critics say the problem stems from the substantial stiffness of the helmets that they have to use to withstand the hard impacts in SNELL testing. The EPS foam inside the helmet, which absorbs impact energy, works in a way like the harness on a mountain bike.Just as the suspension on your bike absorbs shock from bumps and drops, so the helmet is made to absorb the energy from head bumps in a fall.

In most falls, the main task of the helmet is to slow your head down immediately at the moment of impact, so that it is not immediately affected by large kinetic energy.

This is more of an EPS foam inside the helmet than a hard outer shell. The foam is made to compress on impact and slow your head down.If the foam does not significantly slow down the movement of your head, your brain will hit the inner wall of your skull, causing a concussion. And if the helmet did not cope with this task, the consequences are usually sad.

The problem with helmets that are overly rigid is that they are designed to withstand the harsh impacts of potential motorcyclist accidents on the road – a similar problem when the suspension of a downhill bike is tuned to withstand a 3m drop on the plane. A helmet with its super stiff shell will not be able to handle small bumps in the same way that a downhill bike with a super stiff suspension will not handle medium bumps and small bumps.

– The Kali Prana Downhill Helmet meets the American DOT safety standard and the European ECE 22.05 safety standard, but does not pass the SNELL tests. Recent evidence proves that this can be a good thing. Photo by Ian Hylands.

When it comes to brain injury, small to medium strokes make the difference. Neurologists have studied the many effects associated with concussions in recent years, and the news will not be good for those who have suffered.Repeated blows to the head have sometimes led to chronic traumatic encephalopathy, a brain condition associated with the deaths of some former NHL (National Hockey League) players. All this led the researchers to the conclusion that concussions can be much more dangerous than previously thought.

Critics also point to the fact that you don’t have to get a lot of concussions, even one can make a big difference in your life. And a single shake can cause attention and memory problems that will continue indefinitely.James Newman, a former head of the SNELL Foundation, has calculated that exposures of 200g or even 75g (which is less than the values ​​figured in the SNELL M2010 certification tests) usually lead to brain injury or more serious consequences.

– Alex Mancini makes Superman to the stone section in Contermanskloof, South Africa. Maybe he’s glad that his helmet is certified to withstand such hard impacts.

Photo by Steven Morrow.

Experts calm down

As a result, SNELL helmets are too tough?

In a 2005 article from Motorcyclist magazine, DOT helmets outperformed their SNELL counterparts in independent tests that simulated crashes at low to medium speeds. This was especially surprising given that the DOT helmets were not designed fleshy enough to pass the SNELL tests.This means that, in theory, they behave better in minor accidents.

Surprisingly, DOT helmets delivered less peak acceleration than SNELL certified helmets at high impact. Raising the question that SNELL testing has indeed become too stringent. Funnily enough, in Motorcyclist magazine’s 32 helmet test, the winner was a $ 79.95 DOT certified helmet that transmitted 67g less peak G in impact than a $ 400 SNELL certified helmet.

After the article was published, SNELL issued a rebuttal expressing doubts about Motorcyclist magazine’s test methods (however, SNELL shifted towards lower requirements for helmet shells – one of the key points in the Motorcyclist article.) But the rebuttal did not diminish the discussion on the topic. The debate reached a boiling point in 2009 when Dexter Ford, author of a 2005 article in Motorcyclist magazine, wrote an article on the subject for the New York Times. Shortly after this article was published, Motorcyclist kicked out Ford, a veteran of three decades with the magazine, allegedly over the threat of a boycott by the helmet makers.

The 2005 story no longer appeared on the Motorcyclist website.

– Kali Protectives founder Brad Waldron at work with one of his DH helmets. Photo by Ian Hylands.

Helmet talk with Brad Waldron

Brad Waldron, a longtime helmet designer and tester, agrees that the softer shell provides more protection in low speed (relative to moto) falls, more typical of Downhill and park riding.We asked Brad ‘ a to clarify the difference between moto and dx helmets, and the possible benefit of a less rigid shell design.

Yes, on average HH helmets are softer. One of the big reasons for this is that the DOT test for motorcycle helmets includes a penetration test, which forces a hard shell to be used. The test basically consists of hitting the shell with a pointed anvil.

SNELL believes that a tougher shell will save lives in peak crashes while sacrificing concussions in less severe crashes.I had this discussion with SNELL at the Indy motorcycle show. I think there are arguments for this, but arguing with SNELL’s arguments is not what I want from this discussion.

Rigid casings are worse when hitting at low speeds. I believe you would like the shell to deform as much as possible. Remember, the body is in motion, remains in motion until force acts on it. If your head hits a hard shell, your brain still moves until it hits the wall of your skull.On the other hand, if the shell begins to break and the foam is soft enough, then the impact energy is dissipated more efficiently and your brain moves more slowly. Slowing down the movement of the brain in your head is a good thing.

Our technology is a casing filled with molded foam, the rigidity of the casing did not change, we did not see any particular benefit in this. When we made the shell much less rigid, we reduced the g force by 20% or more. So I’m a fan of softer shells.Although there are limits here too. It is necessary to look for balance and adjusting the hardness of the shell to be sure that it is not too soft. This type of testing takes a lot of time and effort. Not everyone is willing to put in so much effort

All of these facts raise a number of concerns for mountain bikers who have opted for motorcycle helmets. If this is true and many motorcycle helmets are too stiff to even hit at highway speeds, what does this mean for riders using them in downhill where the typical speeds are much slower? Wouldn’t it be better for riders to choose helmets designed for their typical crashes than helmets designed to hit cars at 120 km / h?

In any case, the choice is yours, but it is worth thinking twice before choosing a helmet or a helmet designed for a bicycle.Since the introduction of ASTM F1952 – the special standard for the safety certification of downhill helmets – many bicycle helmets have met it. Regardless of the debate on the topic, choosing the right helmet for your riding style remains your prerogative, depending on how much you value your head.

Adapted from pinkbike.com

Accelerometer Sensor Helmet Impact Absorption Testing Machine

& Acy; & kcy; & scy; & iecy; & lcy; & iecy; & rcy; & ocy; & mcy; & iecy; & tcy; & rcy; & icy; & chcy; & iecy; & scy; & kcy; & icy; & jcy; & dcy; & acy; & tcy; & chcy; & icy; & kcy; & shcy; & lcy; & iecy; & mcy; & tcy; & iecy; & scy; & tcy; & icy; & rcy; & ocy; vcy; & acy; & ncy; & icy; & iecy; & pcy; & ocy; & gcy; & lcy; & ocy; & shchcy; & iecy; & ncy; & icy; & yacy; & ucy; & dcy; & acy; & rcy; & acy; & mcy; & acy; & shcy; & icy; & ncy; & ycy;

& Scy; & tcy; & acy; & ncy; & dcy; & acy; & rcy; & tcy; & pcy; & rcy; & ocy; vcy; & iecy; & rcy; & kcy; & icy;
& Ecy; & tcy; & ocy; & scy; & ocy; & ocy; & tcy; & vcy; & iecy; & tcy; & scy; & tcy; & vcy; & ucy; & iecy; & tcy; ECE R22 & ​​period; 05 & comma; DOT & comma; JIS & comma; & Scy; & Ncy; & IEcy; & Lcy; & Lcy; & comma; EN1078 & comma; EN1077 & Dcy; & acy; vcy; & lcy; & iecy; & ncy; & icy; & iecy; & vcy; & ocy; & comma; etc CPSC & scy; & tcy; & acy; & ncy; & dcy; & acy; & rcy; & tcy; & pcy; & rcy; & ocy; vcy; & iecy; & rcy; & kcy; & icy;

& TScy; & iecy; & lcy; & softcy;
& Ocy; & ncy; & acy; & icy; & scy; & pcy; & ocy; & lcy; & softcy; & zcy; & ucy; & iecy; & tcy; & scy; & yacy; & dcy; & lcy; & yacy; & icy; & scy; & pcy; & ycy; & tcy; & acy; & ncy; & icy; yacy; & ncy; & acy; & ucy; & dcy; & acy; & rcy; & icy; & ncy; & ocy; & scy; & icy; & tcy; & softcy; & shcy; & lcy; & iecy; & mcy; & shcy; & lcy; & iecy; & mcy; vcy; & ycy; & dcy; & iecy; & rcy; & zhcy; & acy; & tcy; & softcy; & vcy; & lcy; & icy; & yacy; & ncy; & icy; & iecy; & ncy; & acy; & pcy; & rcy; & ocy; & icy; & zcy; & vcy; & ocy; & dcy; & icy; & tcy; & iecy; & lcy; & softcy; & ncy; & ocy; & scy; & tcy; & softcy; & icy; & pcy; & rcy; & ocy; & ncy; & icy; & kcy; & ncy; & ocy; vcy; & iecy; & ncy; & icy; & iecy; & comma; & ecy; & tcy; & ocy; & jcy; & mcy; & acy; & shcy; & icy; & ncy; & ycy; & icy; & scy; & pcy; & ocy; & lcy; & softcy; & zcy; & ocy; vcy; & acy; & tcy; & softcy; HOTOTECH & icy; & scy; & scy; & lcy; & iecy; & dcy; & ocy; vcy; & ncy; & icy; & jcy; & icy; & rcy; & acy; & zcy; vcy; & icy; & tcy; & icy; & yacy; & scy; & icy; & scy; & tcy; & iecy; & mcy; & ycy; & ucy; & pcy; & rcy; & acy; vcy; & lcy; & iecy; & ncy; & icy; & yacy; & CHcy; & Pcy; & Ucy; & scy; & Zcy; & Ucy; & dcy; & icy; & scy; & pcy; & lcy; & iecy; & yacy; & rcy; & iecy; & acy; & lcy; & softcy; & ncy; & ocy; & gcy; & ocy; & vcy; & rcy; & iecy; & mcy; & iecy; & ncy; & icy; & comma; & Acy; & kcy; & scy; & iecy; & lcy; & iecy; & rcy; & ocy; & mcy; & iecy; & tcy; & rcy; & icy; & chcy; & iecy; & scy; & kcy; & icy; & jcy; & dcy; & acy; & tcy; & chcy; & icy; & kcy; & vcy; & ycy; & scy; & ocy; & tcy; & ycy; & pcy; & icy; & kcy; & ocy; & vcy; & ocy; & iecy; & zcy; & ncy; & acy; & chcy; & iecy; & ncy; & icy; & iecy; & comma; & tcy; & iecy; & scy; & tcy; & icy; & rcy; & ocy; vcy; & acy; & ncy; & icy; & iecy; & ncy; & acy; & kcy; & rcy; & icy; & vcy; & ocy; & jcy; & comma; & vcy; & lcy; & icy; & yacy; & ncy; & icy; & iecy; & scy; & kcy; & ocy; & rcy; & ocy; & scy; & tcy; & icy; & comma; & vcy; & rcy; & iecy; & mcy; & yacy; & icy; & ecy; & ncy; & iecy; & rcy; & gcy; & icy; & yucy; & ucy; & dcy; & acy; & rcy; & acy; & icy; & tcy; & period; & Dcy; & period; & Ncy; & acy; & rcy; & acy; & bcy; & ocy; & tcy; & iecy; & tcy; & icy; & ncy; & tcy; & iecy; & rcy; & fcy; & iecy; & jcy; & scy;

& Vcy; & ocy; & scy; & ncy; & ocy; & vcy; & ncy; & ocy; & mcy; & tcy; & iecy; & khcy; & ncy; & icy; & chcy; & iecy; & scy; & kcy; & icy; & iecy; & khcy; & acy; & rcy; & acy; & kcy; & tcy; & iecy; & rcy; & icy; & scy; & tcy; & icy; & kcy; & icy;

& Pcy; & rcy; & ocy; vcy; & iecy; & rcy; & kcy; & acy; & mcy; & acy; & shcy; & icy; & ncy; & ycy; & ncy; & acy; & dcy; & icy; & scy; & pcy; & lcy; & iecy; & iecy; & icy; & zcy; & ocy; & bcy; & rcy; & acy; & zhcy; & iecy; & ncy; & icy; & yacy;

& Icy; & mcy; & yacy; & kcy; & acy; & rcy; & tcy; & ycy;

Ski rental in Adler and Sochi.Snowboard Rentals

Australian Entrepreneurs Claims To Create First Smart Winter Sports Helmet

Australian Entrepreneurs claim to have created the first smart helmet for winter sports.

Forcite ™ Alpine Smart Helmet with a polystyrene shell contains an HD camera, speakers, shock sensors and a micro computer. All functions are controlled by Alpine’s AI Forcite ™ software and smartphone app.

The camera provides 1080 quality shooting at 120 frames per second, equipped with a wide-angle lens with a viewing angle of 160 degrees.

The

Helmet lets you chat with friends on the slope with its rugged, built-in noise canceling microphone. For communication, Wi-Fi and Bluetooth 4.0 technologies are used. By the way, you can listen to music and answer a call via Bluetooth.

In addition, the helmet has a built-in altimeter that works in conjunction with the Forcite ™ software.

But all this is just an addition to the main function: in case of a strong impact, the helmet activates the transmitter, which reports the GPS coordinates and the altitude of the accident site to the rescue service of the resort.Moreover, the transmitter can be turned on manually if necessary.

The more famous European manufacturer POC has created a helmet that will inform the owner himself that it needs to be replaced. Helmet with the catchy name Skull Orbic COmp H.I. MIPS awarded Popular Science magazine.

This helmet has a built-in sensor that can summarize the energy of impacts, so even if the “shell” has aged due to many relatively small impacts, the owner will be informed that it is time to buy a new helmet.Feature The Skull Orbic Comp H.I. MIPS is a set of sensors distributed inside the helmet that record, store and process any deformations. And if a blow or a series of blows exceeds a predetermined level, the green indicator changes color to red – “throw it out, master!”

90,000 Does a cyclist need a helmet? Or is it better without him?

• David Gibson
• BBC Autos

September 10, 2014

Photo by, Hovding

Why do some cyclists avoid helmets? They are supposedly hot in them, they spoil their hair and generally look ridiculous, say the haters of the helmet.The Swedish company Hövding gives another reason: a standard bike helmet is not very good protection. And the company has a solution to this problem, although with its own peculiarities, as the correspondent of found out

BBC Autos .

In 2006, industrial design students at Lund University in Sweden, Anna Haupt and Teresa Alstin, decided to develop an improved bicycle helmet as a training project. The main issue was aesthetics: not all people (including the mentioned students) like to wear a protective helmet on their heads.

In addition, after conducting research, they found that the traditional plastic foam helmet tolerates incompatible overload in too many accidents.

As a result, the companions developed an innovative, self-inflating collision helmet. It protects a much larger area of ​​the head and neck and provides improved cushioning.

The device of the Hövding company, founded by Anna and Teresa, is essentially a wearable airbag. It is produced in collaboration with Alva Sweden, a specialist in car cushions.The technological stuffing of such a “helmet” is quite similar to what protects motorists: motion sensors are hidden in the collar, which are specially tuned to respond to overloads typical for bicycle accidents.

The sensors are rechargeable via the USB port and can operate up to 18 hours on a single charge. The device turns on when the cyclist puts it on and fastens the zipper, combined with the power button. When the device predicts an imminent collision, it is inflated with helium from a built-in balloon in a split second – before the head hits the asphalt or a car – and remains inflated for a few more seconds in case of repeated impacts.

Photo author, Hovding

Photo caption,

Hovding bicycle helmet on the neck: no hairstyle problems

Independent tests carried out by the Swedish insurance company Folksam have shown that a Hövding helmet absorbs impact energy three times more effectively than conventional bicycle helmets …

What about cons? The main ones at the moment are the price and the degree of availability. The helmet costs 299 euros and is sold only in Europe, although the company plans to expand its sales geography.In addition, Hövding does not protect the rider from flying objects and may not work well on a cyclist with excessively lush hair.

Since the helmet’s sensors are only tuned for bicycle accidents, it is not suitable for skateboarders, motorcyclists or skiers.

Photo author, Hvding

Photo caption,

Unfortunately, the Hovding helmet is not suitable for skateboarders, motorcyclists or skiers

When you ask the director of the company Fredrik Karling about other potential uses of the inflatable helmet, he evasively replies: “Design research Hövding are confidential.But we can say that consumers are showing great interest in other areas of helmet use. “

More and more people on our planet are switching to bicycles. Well, now at least some of them can ride with good protection, without spoiling their hair.

Modified Drop Tower Impact Tests for American Football Helmets

Motivation
The main objective of this modified drop tower test method is to more closely represent the impact of the American football helmet system on the field of impact and to help expand safety standards.The entailed test method can provide the knowledge of systematic response helmets required for the effective development of a reinforced headgear to prevent concussion. The occurrence of concussions is plagued by contact sports such as American football. In the United States alone, sports-related concussions are estimated to occur 1.6 to 3.8 million times each year. ¹ A soccer player can have over 1500 head impacts each season. ^{2, 3} While the magnitude of most exposures can be sub-shocking, the accumulation of these exposures can lead to long-term brain damage due to exposure to an induced neurodegenerative disease known as chronic traumatic encephalopathy (CTE). ⁴ CTE is associated with the accumulation of tau protein in the brain, resulting in memory loss, behavior and personality changes, Parkinson’s syndrome, and speech and gait abnormalities that sometimes lead to suicide. ⁵ Football helmets have made several technological advances over the past 15 years, but even today the most modern helmets do not completely cushion all the falling forces on the helmet and therefore athletes still suffer concussions. A study by Barch and et al. ⁶ showed that in many cases supervisor exposure doses and traumatic brain injury risks, while dark vintage Leatherhead helmets were comparable to those worn widely used 21 – century helmets illustrating the need for improved design and testing standards of football helmets. Specifically, the NOCSAE ⁷ certification does not require a large helmet to be included in a helmet drop test. The added rigidity from the tone of a large helmet attached to the helmet would drastically change the overall mechanical response.The present study proposes a method to provide more robust helmet safety standards that will serve as a driving force to promote safer helmet design.

Background
Head Injury Metrics
The exact biological mechanisms associated with concussions remain unidentified. Although much has been done in an attempt to quantify the tolerances of head injury for various measures of injury, disagreement has arisen in the biomedical community regarding these criteria.These mechanisms of injury must relate to multiple individuals: linear acceleration, rotational acceleration, exposure duration, and impulse. ^{8, 9, 10, 11} Several Injury criteria have been used to define contusion as a measure of linear acceleration. Wayne State Tolerance Curve (WSTC) 12, ^{13, 14} was designed to predict skull fracture for frontal impact car accidents by defining the threshold curve for linear acceleration versus duration of exposure.The WSTC served as the basis for other injury criteria such as the Severity Index (SI) ¹¹ and Head Injury Criterion (HIC), ¹⁵ , which are the two most commonly used criteria. SI and HIC as a measure of severity impact based on weighted integrals of linear time acceleration profiles. While these criteria define threshold values ​​for linear acceleration, other criteria have been proposed to account for rotational acceleration, such as the head impact power index. ^{8, 10, 16} Today’s helmet testing standards often use an injury criterion based on the Wayne State to have alerance curve (namely ICC or SI), or peak acceleration criterion, or in some cases both. While some changes are needed to add angular acceleration to the standard performance criteria, linear acceleration criteria on the basis remain dominant.

In this study, the metrics used to assess the relative safety that each helmet provided were the apex of the resulting values ​​for acceleration, SI, and SVD.Of these indicators, only SI is used for evaluation in the current National Working Committee for Standards for Sports Equipment (NOCSAE) Football Helmet Standards. SI is based on the following equation,

(1)

where A is the translational acceleration of the center of gravity (CG) of the head, and T is the acceleration time. ^{11, 17} SI was calculated according to the standards NOCSAE ^18, where the calculation is limited to 4 G threshold on the resulting acceleration curve.SVD values ​​were calculated according to the following equation,

(2)

where a translational acceleration CG of the head and t ₁ and t ₂ represent the start and end times, respectively, of the interval at which the HIC reaches its maximum value. All values ​​of CTG calculated in this study were MKH _36, where the duration of the time interval is limited to 36 ms.

NOCSAE Football Helmet Test Standards
NOCSAE
Review In 1969 NOCSAE was formed to develop performance standards for American football helmets / faceguards and other sports equipment with the aim of reducing sports injuries. ¹ 7 The NOCSAE Football Helmet Standards were developed by Dr. Voigt Hodgson ⁹ Wayne State University to reduce head injuries by establishing attenuation and structural integrity requirements for football helmets / faceguards. These standards include football helmet test certification and annual recertification procedures for helmets. In 2015, NOCSAE implemented a quality assurance program requiring the use of a specific American National Standards Institute (ANSI) accredited helmet certification body.

Test Method NOCSAE
NOCSAE Football Helmet The standard does not include testing helmets with faceguards as this requires removing them before helmet drops are carried out. NOCSAE helmet test standards ¹⁷ use a two-wire drop crusher that relies on gravity to accelerate the dummy helmet combination of required impact speeds. NOCSAE head model with instrumental shIth triaxial accelerometers at the center of gravity. The combination of a dummy head and helmet was then dropped at specified speeds onto a steel anvil covered with a 12.7 mm thick ebonite Modular Elastomer Programmer (MEP) pad.On impact, the instantaneous acceleration is recorded and the SI values ​​are calculated. These SI values ​​are compared with the pass / fail criterion for a variety of required exposure locations and speeds and temperatures, including the environment and high exposure temperatures. If the obtained SI value for any impact violates the threshold, the helmet will not pass the test.

A separate standard test method is used for the certification of the football big helmet. The NOCSAE Football Grand Slam standard includes an analysis of structural integrity, as well as an assessment of the impact of the attenuation characteristics of the helmet and chin strap of their attachment system.Each exposure measurement must be below 1200 SI in order to pass the test, without facial contact and without intermittent failure of any component as defined by the NOCSAE standard. ¹⁹

There is a proposed optional NOCSAE (Linear Impact (LI)) test ²⁰ which includes a helmet with a Grand Slam, but it is not suitable for certification of a football helmet because it cannot recognize the influence of the crown. LI uses a pneumatic ram to act on the helmet, located on the NOCSAE dummy equipped with a hybrid III dummy neck mounted on a linear bearing table in order to induce angular acceleration.For this reason, the LI test is an optional test to the current two-wire NOCSAE drop test procedures and is not a replacement. ^{20, 21} Instead of testing LI, we propose to simply add two more scenarios to the current two-wire drop test procedure.

The NOCSAE Standard Test Method for Certification of Football Helmets currently includes six Locations Prescribed Impact and one Random Impact Location.Prescribed exposure locations include the following: Front (F), Front Boss (FB), Side (S), Rear (R), Rear Boss (RB), and Top (T). The random exposure location test can select a region from anywhere within the helmet’s defined acceptable exposure area. Impact sites for our modified NOCSAE tower drop tests include replacing the previously identified Front and Front Boss impact sites with what has been named as Front Top (FT) and Front Top Boss impact sites (PTB).Our front-top and front-top Top Boss impact points are identical to the front-top and right-front Boss impact points of the NOCSAE standard for Lacrosse helmets, which also include a big helmet for drop tests. ²² The helmet shell impact locations, including the replaced front and front Boss seats, are depicted in Figure 1 In addition, the modified helmet test method of our present study includes two Impac Grand Slam seats, which were named FG front and FG to bottom.The two impact locations for the Grand Slam are identical to the required impact locations for the current NOCSAE Grand Slam certification procedures. The eight impact locations for the modified NOCSAE impact tests of this study are shown in Figure 2.

Figure 1: Approximate impact location for football helmets. Six currently required NOCSAE impact helmet drop test seats, Front (F), Front Boss (FB), Side (S), Top (T), Rear (R), and Rear Boss (RB), plus two seats the impacts are projected, Front Top (FT) and Front Top Boss (PTB).Note: The NOCSAE Standard Test Method for Safety Helmets does not include the Front Top and Front Top Boss Impact Locations (shown in red) and for this study, they replace the Front and Front Boss Impact Locations. (Image modified from NOCSAE DOC. 001-13m15b)

Figure 2: Modified NOCSAE test rig , showing eight impact locations. Front Top, Front Top Boss, Side, Grand Slam (FG) Front, Back, Rear Boss, Upper and Lower Grand Slam (FB).Note: the NOCSAE standard does not include attachments and the big helmet here is the front-top and front-top Top Boss replace the standard Front and Front Boss impact spots. (Image modified from NOCSAE DOC. 002-11m12) Please click here to view a larger version of this figure.

Helmet designs have evolved progressively over the past decade, while NOCSAE’s soccer helmet standards have never included a large helmet with the ELMET in evaluating the technical performance of a soccer helmet.Although, more recently, an amendment has been made to include a pass / fail value of 300 SI for low impact velocities (3.46 m / s), the total credit / fail limit of 1200 SI has not changed since 1997 ¹⁷ Until 1997, NOCSAE used 1500 SI Pass / Fail criterion. Hodgson and et al. (1970) showed that SI values ​​of over 1000 are life-threatening, while SI values ​​of 540 produced linear skull fractures in non-cadaveric impact test helmets. ²³ Most modern football helmets have shown to pass well below the 1200 SI limit, but not all below 540 SI.

Subscription Required. Please recommend JoVE to your librarian.

Video recorders with shock sensor | ALLO

Buy car DVRs Recording activation By shock / braking / acceleration sensor in Kiev in the ALLO.ua online store at an affordable price “as easy as shelling pears”. You need to enter the product page, having read the characteristics, descriptions and reviews – and make a purchase. Sale of car DVRs. Recording activation by shock / braking / acceleration sensor is carried out throughout Ukraine.Delivery across Ukraine: Zaporozhye, Dnipro, Nikolaev, Zhitomir, Kharkov, Chernivtsi, Odessa, Exactly, Poltava, Cherkassy, ​​Kropyvnytskyi, Kherson, Ivano-Frankovsk, Vinnitsa, Kiev and other cities of Ukraine.

product code: 843676

Video recorder 70mai Dash Cam M300 Gray

0 Add to compare

Add to wishlist

Sensor

SC3335

video

Number of cameras

1

Warranty period

12 months

product code: 668529

DDPai MOLA N3 DVR

0 Add to the list of wishes

Sensor

CMOS

Video resolution

2560×1600

Viewing angle

140 °

Number of cameras

1

5

905 914

905 Warranty 914 0517

Weight

250 g

product code: 852296

DDPai Z40 GPS video recorder

0 Add to compare

Add to wishlist

Sensor

Sony IMX535 video 2592×1944

Viewing angle

140 °

Number of cameras

1

Built-in screen

Yes

Diagonal

2.0

product code: 536587

DVR 70mai Dash Cam Lite Midrive D08

0 Add to compare

Add to wishlist

Sensor

Sony IMX 307

905 905

Viewing angle

130 °

Number of cameras

1

Integrated screen

Yes

Diagonal

2.0

product code: 852298

DVR DDPai Z40 GPS Dual

0 Add to compare

Add to wishlist

Sensor

Sony IMX335

Angle of video view

140 °

Number of cameras

2

Built-in screen

Yes

Diagonal

2.0

product code: 725817

DVR DDPai MOLA N3 GPS

0 Add to compare

Add to wishlist

Sensor

CMOS

Video resolution 256017

140 °

Number of cameras

1

Warranty period

12 months

Weight

250 g

product code: 444223

MIDR2 Camcorder

camcorder code: 444223

Dash camcorder MIDR6 SmartR 0 Add to compare

Add to wishlist

Sensor

Sony IMX 307

Video resolution

1920×1080

Viewing angle

90 °

5

905

cameras 1

Warranty period

12 months

product code: 852295

DVR DDPai Z40

0 Add to compare

Add to wishlist

Sensor

Sony 90 IMX335

video

Viewing angle

140 °

Number of cameras

1

Built-in screen

Yes

Diagonal

2.0

product code: 776405

Video recorder 70mai A800S

0 Add to compare

Add to wishlist

Sensor

Sony IMX415

Video resolution 90×514

Video resolution

140 °

Number of chambers

1

Integrated screen

Yes

Diagonal

3.0

product code: 859634

DVR 70mai A400 RED

0 Add to compare

Add to wishlist

Sensor

GC4653

51240 905 905

5 905 905 905 905 905 905 905 905 905

145 °

Number of chambers

1

Integrated screen

Yes

Diagonal

2.0

product code: 843677

DVR 70mai Dash Cam M300 Navy

0 Add to compare

Add to wishlist

Sensor

SC3335

5

video

Viewing angle

140 °

Number of cameras

1

Warranty period

12 months

product code: 852297

DVR DDPai Z40 Dual

Add to comparison Wishlist

Sensor

Sony IMX335

Video resolution

2592×1944

Viewing angle

140 °

Number of cameras

2 Built-in

Diagonal

2.0

product code: 792399

DDPAI A2

0 Add to compare

Add to wishlist

Sensor

OmniVision OV4B10

video angle

130 °

Number of cameras

1

Warranty period

12 months

product code: 859633

Video recorder 70mai A400 Ivory

0 Add to wishlist

Sensor

GC4653

Video resolution

2560×1440

Viewing angle

145 °

Number of cameras

1

a gonal

2.0

product code: 668527

DDPai Mini 3 DVR

0 Add to compare

Add to wishlist

Sensor

Omnivision OV05A10 Resolution

905 video

5

Number of cameras

1

Warranty period

12 months

Weight

48 g

Product code: 507342

oKoRador 03502 Add To compare

Add to wishlist

Sensor

CMOS

Video resolution

1920×1080

Viewing angle

170 °

Screen number

Camera

Built-in

Yes

Diagonal

4.0

product code: 633787

DVR XOKO DVR-025 Three cameras

0 Add to compare

Add to wishlist

Video resolution

1920×1080

Viewing angle 17017

Number of cameras

3

Built-in screen

Yes

Diagonal

5.0

Warranty period

12 months

12 months