Sports Engineering | Re-Engineering Labs

Developing IMU Sensors For Capturing Motion In Sports

Posted on August 4, 2018 by Julian Chua

IMU sensors are pretty useful because when strapped to the right location and given the right context they can provide very insightful information about an athlete’s (or anyone’s) movements. In this post, we are going to look at a couple of options in the market that allows us to skip the hardware development and jump right into the application development. Feel free to skip to the different sections that interest you:

[ Intro To IMUs – mbientlabs – Notch Sensor – Notch Mocap Test – Custom Sensors]

Intro To IMUs

In case this is the first time you are hearing about IMU, here’s a brief intro. IMU stands for Inertial Measurement Unit; it is an electronic device that typically has accelerometers, gyroscopes and magnetometers, and it measures its own acceleration, angular rate (or spin rate) and surrounding magnetic field. IMUs are not only used in sports, in fact, it is used in many consumer electronic devices. Our smartphones for one has IMUs for detecting the orientation of the phone and changing the display to portrait or landscape. The IMUs also allows for functions such as undoing texting errors, a spirit level and motion sensor games. If a user carries the phone with them in their pockets most of their waking hours, it can act as a pedometer counting steps and detect when the user is sedentary. For runners who use running apps to track their runs, IMUs enable some apps to track indoor runs and cadence. Sports Engineering Researchers have used smartphones for tracking wheelchair rugby activities and classifying different sporting activities.

As great as the smartphones are with inbuilt IMU, GPS and processing power to give us real-time analysis, we don’t really want to strap an expensive smartphone onto a football player’s calf to monitor their kicking or tape an iPhone to a tennis racket to measure swing metrics. That’s why companies like Qlipp has developed sensors for tennis or Zepp which has sensors for a number of bat-and-ball or swing type sports. Then there are sensors for rowing, running, surfing, mountain biking and more. There are also different sports equipment that has in-built IMU sensors. Like smart balls (basketball, football, cricket ball etc), smart shoes, smart helmets, smart rackets etc, it could go on and on.

But sometimes we might still not find a sensor product on the market that is right for our sports or health application. So we explore the option of developing something on our own. Fortunately, we don’t necessarily have to start from scratch* because these days there are generic IMU sensor platforms that are designed and built for people who want to develop a sensor for a custom application. They often have the standard 9-DOF (degree of freedom) sensor setup and come with software SDK that allows developers to build their own applications for processing and analysing the data. Let’s look at a couple of options below.

[*when I say scratch, I mean getting sensor boards from SparkFun, Adafruit, Seeedstudio, Tindie etc]

mbientlab

mbientlab successfully launched their first Bluetooth IMU sensor on Kickstarter. They pitched it as a development and production platform for wearables with simple API for iOS and Android. There was some simple soldering required when people bought the first product. I didn’t get one from that campaign but I did get a later updated version which they called MetawearRG. What impressed me when I first got it was the size of it – it’s small and compact and I could use it to build/redesign a smart basketball prototype for a client. Then when I started testing it, I found that their API was really easy to use and I could use their sample iOS app to build a custom app for testing within a (reasonably) short time.

: Smart Basketball Prototype and Watch app for tracking optimal shots

Since then, they have made many other versions of sensors with:

slightly different sensor configurations,
options of coin cell or rechargeable lithium battery,
accessories such as cases, clips or wristbands,
sensor fusion firmware,
cloud services, and
hubs to manage multiple sensors.

: Metawear RG with custom 3d printed sleeve/case (L) and Metamotion (R)

I haven’t had the chance to try everything but I have to say, I have had a good experience using their Metawear and Metamotion sensors to build various proof of concepts and I am still using them for a number of projects. The sensor data can be streamed to your smartphone or logged on the device. In terms of API support, on top of iOS and Android, they have added Python, C, C# and Javascript, so developers can build stuff on various platforms.

Sample/Template Metawear iOS app for testing

Looking at their new website revamp and some recent emails they sent out about new platform developments, they seem to be putting more focus into the allied health space, in particular, measuring range-of-motion (ROM). They are currently beta testing an app called the MetaClinic and it looks like they are using skeleton-tracking the likes of motion capture systems which would probably mean we need to use multiple sensors. That should be interesting.

MetaClinic App by mbientlab

Notch Sensors

Notch also launched on kickstarter, in fact slightly earlier than mbientlabs’ campaign. They had an interesting concept of integrating individual IMUs into custom designed clothing using pockets in discreet locations. Unfortunately, they weren’t successful at that instance. Their initial use case probably wasn’t strong enough. So I guess the founders went back to the drawing board, revamped it all and went with the “motion capture” approach for developers.

Notch sensor with elastic band and clip

With the new design, the shape of the IMU sensor is essentially the same but they have ditched the micro-usb in each IMU for contact pins and made it water-resistant (IP67). They also designed elastic bands of varying lengths with a sensor clip and a user can secure each sensor up to 15 different locations on their body including head, chest, upper arms, wrists, hands, waist, thighs, ankles and feet. So instead of selling individual IMUs, they sell a kit of 6 IMUs with a set of elastic bands, and if a user wants to do a full (body) setup, they will need 3 kits.

The Pioneer Kit: 6 IMUs with charging case and elastic bands with clips.

A quick test and review (for biomechanics)

I had the opportunity to run a short pilot test with one (the pioneer) kit in a biomechanics lab. I used the lower body setup which used all 6 IMUs strapped on my chest, waist, thighs and shins/ankles. In terms of setting up, it was pretty straightforward. After following an initial calibration procedure of all the IMUs in the case, I put on the bands and clipped each IMU to the right location according to the different colours as indicated on the app. The only thing is putting on the bands takes a bit of practice and I had to swing around to check that the bands are not too tight and restricting movement. Even though I don’t have muscly quads, I felt that the bands were somewhat tight and needed adjusting after a while.

Setting up the Notch IMUs for lower body measurements

For testing, I did a simple protocol of walking, stopping and doing 3 squats of varying depths. Then I compared my knee angles measured on the notch and the motion capture system. A few quick things that I took out of the knee angle measurements were:

The angle measured by Notch is the exterior angle while the motion capture system looks at the interior angle. So it needs a quick recalculation before comparison.
Assuming the motion capture system is the more accurate measurement, Notch had a larger error as squats went deeper.
But for walking, the knee angles measured were quite close.

It’s wasn’t a very elaborate test but even from this simple outcome, I can safely say it’s probably not the best tool for accurate joint angle measurements. Although for a quick 3D visual feedback on movements, it might work. Here’s the clip of me doing the test described above (feel free to rotate the video to get different perspectives):

Further to that, I could only download angle data. If I wanted the raw sensor (acceleration and gyro) data, I would need to pay for an extended license that is renewed annually.

In terms of custom development support, they used to have support for iOS but they seem to have taken that off now and only have support for Android which I thought is a bummer. I am guessing they have some issues with getting it right on iOS. Hopefully, it is just temporal and they will resolve it soon. For Android developers, it looks like they have pretty good support and even provides a template app. I have to add that there is a fair bit of fine print I need to agree to before I can get access to their SDK. If I read it right, they basically want a licensing fee for using/commercialising their SDK.

Custom Sensors

Both of the above IMU sensors have similar specifications when it comes to measuring acceleration (using accelerometers) and angular velocity (using gyroscopes). The typical measurement range for accelerometers is +/-16g (that’s 16 times of gravitational acceleration), and for gyroscopes, it’s +/- 2000 degrees per sec. For many applications, this configuration is fine. But there might be some cases where higher acceleration needs to be measured and that goes beyond 16g, like shocks or high impact collisions. Or I might need high-speed rotations to be tracked and 2000 degrees per sec is too low, like measuring the spin of a cricket ball or gridiron football (which can come close to 3600 degrees per sec or 600rpm as demonstrated here by Drew Brees).

Spin rates of a gridiron football during a throw test

As briefly mentioned earlier, hobby electronics stores like SparkFun, Adafruit, or Tindie would be a good place to start when looking for accelerometers and gyroscopes of different specifications. There are also lots of microcontrollers with Bluetooth Low Energy (BLE) built-in that are Arduino compatible so we can program them with the Arduino software. One that I found pretty handy is this one called Blueduino which comes with a Lipo charger add-on (and add-ons are great) and that can be found on Tindie.

The gridiron football sensor prototype using the Blueduino

Final Word

For those who are in research and possibly need Matlab and software support for building custom Matlab programs, definitely check out Sabel Sense sensors (Australia). Else, I reckon the mbientlab sensors would be a great option for starting a custom development. If I get a chance to trial their Metaclinic platform, I will put up another post. Meanwhile, do drop me a message here if you need assistance or advice in any of the options above and feel free to leave a comment if you know of better/different solutions out there. With that, thanks for reading!

The Kayak Tech Survey Outcome

Posted on June 30, 2018 by Julian Chua

Almost 6 months ago, I wrote a short post about (what I thought was) a lack of technologies for monitoring training in flatwater or sprint kayaking. To make sure that it wasn’t just me thinking that way, I created a survey and sent it to a couple of kayaking friends who graciously helped spread the word. I also posted a link to the survey on social media (i.e. Twitter) which I think wasn’t quite as effective. Overall, I didn’t get a big response but it still gave me a peek into things. So let’s dive into it and see what it’s telling us.

Key Stats

So here are some key stats as captured by Typeform:

There were a total of 120 visits, of which 101 were unique and out of the 101, there were 37 responses. This means a 36.6% response rate. Among the 37 responses, 14 were done on Laptops, 23 on Smartphones, and none on Tablets.

Screenshot of Typeform Key stats

Some Details

Then onto the 6 questions:

Training frequency per week – 30 out of the 37 responses said they train at least 2 times a week or more.
Yes/No to use of technology during training – 30 out of 37 use some form of technology to track their training
Regarding the type of technologies they use – 29 use a GPS watch, 19 use a heart rate strap, 8 use a smartphone app, 3 use Motionize, 3 use Vaaka Cadence, 2 use a SmartWatch, and 1 uses a GPS + IMU unit. (note that some people use more than 1 piece of technology)
The number who do not use technology – 5 responded that they do not use any technology and the most popular reason is that they have not tried them
What they liked about their current technologies – Being able to track Heart Rate (n=18) is the top thing that people liked. This is followed by Pace (14), Speed (11), Distance (8) and Stroke Rate (4) (or cadence).
Regarding improvements they would like to see, everyone had slightly different preferences. But in essence, 9 said they would like a kayaking specific device or app, 6 wanted stroke rate available in their existing devices, 6 wants some form of power monitoring (that is affordable), 4 would like to see stroke/technique analysis, 3 wants greater accuracy and reliability in their tracking, and 2 would like a better visual of their data.

[If you would like to see it on Typeform, here’s an overview of responses to the first 4 questions: link]

Even though I only had 37 responses, there was a good mix of opinions; and I take away 3 key things out of the above data:

The GPS watch is the most commonly used tech. It makes sense because it is a multi-functional device – it can be used for running, riding, swimming or just for everyday use as a watch.
More than half (19) of the people use a heart rate strap and it seems most of them value the heart rate data.
Although there are technologies out there that can be used/adapted, 23 out of the 30 still wants some form of improvement to their devices. The most common feedback is there isn’t a kayak specific device or app.

I reckon most people would have a similar setup as the athlete in his Instagram image below – wearing a heart rate strap and with a GPS watch mounted onto the kayak in front of the cockpit.

Tom Liebscher’s Instagram photo (link to original photo)

Additional Info

Also from the few conversations I had with some of the kind people who did the survey, most (if not all) GPS watches don’t track stroke rate, and the accuracy of the speed measurement during short distances/sprints/intervals are not very good.

What I didn’t get a lot of information or feedback about are those kayak specific technologies that are actually in the market like Vaaka Cadence, Motionize and Kayak Power Meter. It seems like not many people have used them. This could be because of the price or a lack of opportunity to try it. I will be digging a little bit deeper into that.

What next

The main outcome I took out of this little exercise is that my initial hypothesis has its merits, and it’s worth pursuing this further. The few options that I am exploring further going forward are (in that order):

Smartphone app (likely iOS)
A kayak specific device like a kayak computer
Garmin Connect app

As this is really just a side project here at ReEngineering Labs, the progress might not be as quick. Nevertheless, it will be moving forward and I will be posting updates every 3 months.

If you are reading this for the first time, please do check out the earlier post here, and have a go at the survey here. If you would like to give your input on kayak technologies or even be part of this project, drop me a message here. To get notifications about this project, simply subscribe on the right.

With that, thanks for reading!

Customising What Athletes Wear And Use – 3D Scanning And Other Tech

Posted on March 2, 2018 by Julian Chua

The term bespoke or tailor-made brings to mind an image of a tailor measuring up a customer with a measuring tape so that he can make a suit that fits the customer. Four things typically happen in the whole suit-making process: 1) measuring the customer, 2) picking the preferred materials, 3) making the first fitting and 4) making adjustments based on the first fitting and customer’s feedback. The fourth step might repeat if the subsequent fittings are still not satisfactory. It is a tedious process but the outcome is getting the perfect fit for the customer.

In sports, athletes can have custom made helmets, shoes, protective gear, mouth guards, seats, suits, prosthetics and other adaptive equipment. We are not talking about just having custom aesthetic designs that are unique and represents the athlete. Custom made apparel or equipment that fits a specific athlete’s shape and style can not only improve comfort, protection, their range of movement, aerodynamics and overall performance. Let’s have a look at what technologies or methods are involved in customising them.

3D scanning

3D scanning is able to capture a lot more detailed measurements including curves (down to the millimetres) which standard ‘straight-line’ measurement tools like the measuring tape or vernier callipers are not quite capable of doing. Here are some parts of the body that are 3D scanned in order to be fitted:

The athlete’s head; it can be scanned to create a 3D model, which is then used to design and make a custom fit helmet liner for football players.
The feet are also commonly scanned to produce custom orthotics or high-performance athletic footwear.
The lower body where athletes need to be seated or positioned in a certain way during competition; and it helps with designing custom-fit equipment, enhancing comfort and aerodynamics. (e.g. slalom kayak seat or racing wheelchair seats or a luge)
Stumps (amputations or limb difference) are scanned to help design better fitting prosthesis.

The more common 3D scanners are hand-held scanners like the Artec3D Eva or Creaform3D. They are typically portable and great for scanning around an object or body part. One of the downsides I find is the person doing the scan needs to have steady hands to maintain continuation/tracking and it takes some practice to get a scan right. There are measuring arm scanners that are basically a robotic arm that moves in multiple axes and has a laser scanner or touch probe at the end. The user moves the scanner/probe at the end of the arm around the object and translates the coordinates to a 3D model. It helps with the problem of shaky hands but it might take longer for the probe to travel around the object. Terrestrial laser scanners are capable of scanning an entire stadium but might be an overkill to scan a wrist or a hand. There are also laser scanners built specifically for the foot where the foot is placed into the scanner and the scanning is done in just 15 seconds or less. Another increasingly popular 3D scanning method is photogrammetry. It is a good and cheap option that allows ‘scanning’ to be done with just a smartphone camera and the key factor is really the software.

Kayak Athlete (Jess Fox) being scanned with a Creaform scanner (source: 3D systems)

Moulds

Before 3D scanning, moulds were probably the next best thing to getting the shape of a foot or stump or mouth. In some cases, moulds are still used due to a lack of access to 3D scanning and it is an effective low-cost solution in developing countries. In the case of the mouth guard, getting the mould or impression of the athlete’s teeth and gums is still the best if not the only way to make a custom mouth guard. Athletes can get the impressions themselves using a DIY kit or go to a dental clinic and have the dentist or dental prosthetist ensure that everything is aligned properly. There is also this custom ski boot liner that is designed to be fitted while the user is wearing it and the ski boot liner is injected with polyurethane foam that moulds around the wearer’s feet and solidifies after a short time. If you find it hard to imagine how that works, check out this video about the custom ski boot fitting process that also includes foot scanning and assessment:

3D Motion Capture

Motion capture or MoCap for short is typically used for biomechanical analysis. The typical ‘gold-standard’ MoCap systems are the optical systems. Athletes are (sometimes) made to put on compression garments and have markers placed on the joints that need to be analysed. Then multiple cameras set up around the athletes capture their movement. An example of customisation using Mocap is bike fitting systems. MoCap based bike fitting systems by STT Systems or Retul analyse the athlete’s posture and various biomechanical parameters and recommend an ideal configuration and position. It results in a combination of improved ergonomics as well as performance. Another application that utilises MoCap is golf fitting. The athlete’s golf swing is analysed during the MoCap session and the software breaks down the data and looks at key swing characteristics of the athlete. Then with reference to a huge database of golf swing profiles, a recommendation is generated for the clubs best suited to the athlete’s swings.

Note: There are many other optical (MoCap) systems out there for bike or golf fitting and some of their technology vary and some of them incorporate high-speed cameras. There are also inertial sensing systems and different products will have different levels of accuracy but they all track 3D motion.

An example of a bike fitting mocap system from Bioracer Motion.

Other Complementary Tech

Sometimes, applying any of the above technologies alone is not enough to complete the customisation process and they are complemented with other measurements or sensing technologies.

Pressure sensing technologies are often used for gait analysis and customising footwear. It gives the podiatrist a better idea of how the athlete walks/runs, where the pressure points are and which parts of the sole require more support. They are also used in golf fitting clinics together with Mocap to provide data on the golfer’s balance and pressure distribution during each swing.

3D printing almost goes hand in hand with 3D scanning and we will find in many links or examples above where 3D printing has been utilised to prototype the equipment and sometimes even used as the final product in competition as seen in this paracyclist’s prosthetic leg.

With customisations that are trying to improve aerodynamics, they usually need to perform wind tunnel tests (or aero tests) or simulations. The results of the wind tunnel tests will provide feedback for further design optimisations such as the cycling helmet. And the team at NTNU has even gone to the extent of 3D printing a model of Chris Froome to test and optimise his time trial suit.

Luca Oggiano and the Chris Froome 3D replica in the NTNU wind tunnel (source: NTNU)

Final word

We are in a period where customisation of sportswear and equipment is slowly becoming a norm. Other than the improvement of technologies and processes involved in customisation, the mindsets of athletes have also shifted to see the benefits of wearing and using tailor-made equipment. With major shoe companies like Nike, adidas and New balance partnering with technology companies to further explore performance centred customisation, it will be interesting to see how the technologies will progress and what boundaries can be pushed with customisation.

What else do you think could be or should be customised for an athlete? Would you like to explore making something unique or bespoke? Do leave a comment or feel free to reach out. With that thanks for reading!

Technologies Used To Monitor Training In Sprint Kayaking [Survey]

Posted on January 20, 2018 by Julian Chua

What is Sprint (or Flatwater) Kayaking

In case you are haven’t heard of the sport, Sprint Kayaking isn’t the most popular sport in the world. In fact, it isn’t a very easy sport to get into. For example, if I am new to the sport, I might need to join a club to get access to the equipment and training programs. Then I would sign up for an introductory course of sorts to learn the basics of kayaking on the water and safety in the water. After I sort out the basics, which is probably done on more stable kayaks, I will try to move into the kayaks designed for sprints. These sprint kayaks will be a lot more tippy but they allow the trained paddler to go on the water really quickly – hence the name sprint kayak. The length of the process from being new to the sport to being able to comfortably paddle on a sprint kayak will vary between individuals but I would say it is between a few months to a year. Then to be really good in the sport will take years of training or 10,000 hours as Malcolm Gladwell popularised in his book Outliers. [There are many debates on the actual number of hours (to become an expert in anything) but the point is: it’s hard work.]

My own brief experience in the sport

Years ago when I was in the sport as a teenager, the only technology we used was the stop-watch that took the time of our 200m/500m/1000m sprints or it was used as a timer for doing interval sessions. Back then, I only competed at the national level and never went further. Work and life commitments took over and I even moved to a different city. Now with a young family, having time to go flatwater kayaking is quite the luxury.

my first kayaking session of 2018

Here comes the “tech” bit

But being a sports engineer, I recently revisited the use of technology in sprint kayaking training and was thinking of a couple of ideas of adopting technologies that are available in the market to help with training. I did a bit of research and it seems like most kayaking people use products that were designed for runners or cyclists to track their training. A commonly used product is the running/cycling app Strava. I know a handful of people who secure their Garmin (or other fitness) watches onto their boat and simply start a “run” to track the session. The data then goes onto the Strava platform or any other platform they use.

my “run” on Strava

Nelo has a training app that paddlers can use by securing their Android phone onto their kayaks and it uses GPS and the motion sensors on their phone to track their training. The great thing about their app is that it incorporates a Coach’s app that monitors up to 6 different paddlers. There are also a couple of iOS apps on the market that tracks water sports of various kinds including waterspeed app or paddle logger. These ones are a bit more generic.

Then there’s also sensor products specific for paddling sports such as the Vaaka Cadence sensor, the Motionize sensor, and the Kayak Power Meter.

There might be some more that I haven’t come across or they are only used in research labs at the moment. But even with what seems like a good range of training products, I still feel that there is something missing with all these different products. Maybe it is just the sports engineer in me that thinks that way. I am keen to speak to other canoeists/kayakers/paddlers out there who may or may not use technology in their training and get some feedback.

So if you are a canoeist/kayaker/paddler, could you please fill out this survey: link. Your time and input will be much appreciated and will help shape the future of any tech that’s developed! If what I talked about here interests you, leave your email at the end of the survey and I will keep you posted on future developments. Lastly, please also forward this to your fellow canoeist/kayaker/paddler friends. Thanks!

Do Force Platforms, Pressure Sensors And Smart Insoles Do The Same Thing?

Posted on May 26, 2017 by Julian Chua

Force platforms, pressure sensors and smart insoles are all devices that a person can step on and get some insight related to their weight or the pressure they are exerting on those devices with each step. Other than that, they are quite different and can have very different applications. This post is just an attempt to break that down. Feel free to jump to the different sections that are of interest:

[Force Platforms – Pressure Sensors – Smart Insoles – Summary – More on Smart Insoles]

Force platforms

A Force Platform (FP) is an equipment that you would typically find in a lab – an engineering lab, a biomechanics lab, gait analysis lab, ergonomics lab.. you get the idea. They are great for measuring forces applied directly onto its surface. So when a force platform is placed on the ground, you could step on it to find out how much force you are exerting on the platform. For those platforms that measure multiple axes, you could also slide an object across the platform to measure resistance forces between the surfaces. In sports engineering, FPs enable studies in walking/running gait, jumping (and landing), friction measurements in water polo balls or shoes or gloves, the coefficient of restitution of balls, aerodynamic drag (when placed in a wind tunnel), and more.

An example of a Kistler Force Platform (blue) set up in a wind tunnel

For anyone keen to explore what else is done with force platforms in sports engineering, feel free to do a quick search on these journals: Sports Engineering Journal, Sports Technology Journal or Journal of Sports Engineering & Technology.

Inside Force Platforms

The majority of Force Platforms in the market are set up with multiple Strain gauges or Piezoelectric sensors/elements that deform proportionally to the applied load. There is also the not so common Hall Effect sensing Force Platform which doesn’t require an external signal amplifier/conditioner like the strain gauges and piezoelectric sensors do. They are typically quite expensive and their prices vary with the number of sensors, size, construction, and additional data acquisition (or signal amplifier) systems.

For those who can’t afford the expensive systems and is adventurous enough to try and build something, a sports physics researcher from the University of Sydney wrote a paper providing details of a cheaper home made force plate. Essentially he used Piezos that were manufactured for sonar applications and they cost $25 each. A quick search on Instructables also showed one DIY instruction on making a strain gage force plate. For the slightly less adventurous, there is also the option of the Wii Balance Board as a cheap force plate alternative. There have been some validations of the gaming platform as a standing balance assessment tool, a golf swing analysis tool, and for use in other medical applications. The only downsides of the Wii Balance Board are the user weight limitation and that a custom software is required to access and read the data.

Pressure sensors

There are three main differences between Pressure sensors and Force platforms. Pressure sensors are typically flexible and can be placed on flat or curved surfaces, unlike Force platforms that have to be mounted rigidly. The other difference is pressure sensors do not measure force vectors. Thirdly (or a slight extension of the second), Pressure sensors only quantify pressure that is perpendicular to it (single axis) so it cannot determine shear forces or friction between two surfaces. Due to their flexibility, pressure sensors have been used to determine comfort and fit in aircraft seats for Paralympians, analyse medical mattresses, measure the pressure of grip during a golf swing, pressure distribution on bicycle handlebars, and more.

Single force sensitive resistor (FSR) from interlink electronics

Pressure sensors are mostly made out of either resistive sensors or capacitive sensors. The main differences between them are the sensing material used and their electrodes. They can be constructed as single sensing nodes or they can also be constructed in a row-column array fashion. The advantage of the array or matrix construction (over single nodes) is that it requires fewer connections. In an array, the intersection between each row and column is a sensing node. So a 3 by 3 array creates 9 sensing nodes while only needing 6 connections. On the other hand, 9 single sensing nodes will need 9+1 connections where the +1 is the common ground. The difference becomes much bigger as the number of sensing nodes increases (For example 100 sensing nodes can be achieved using a 10 by 10 array that needs 20 connections or 100 single sensing nodes that need 101 connections).

A simple illustration of Single sensing node Vs Sensor Matrix/Array

However, the matrix construction is not without its challenges. The matrix sensor circuit is prone to parasitic crosstalk (capacitive or resistive). This means when pressure is applied on one node or multiple nodes, the electrical readings for other (unactivated) nodes might be affected. This is also known as “ghosting”. Unless some correction is applied, the measurements/readings become inaccurate and potentially useless. Also, the bigger the matrix, the more complex the correction. But if accurate absolute readings are not required, then it’s fine.

A related side story

I have been following the development of this smart yoga mat that was successfully crowdfunded on Indiegogo back in Dec 2014. Fast forward to 2017, they are still struggling to deliver the product. Looking through their updates, we can see they had to deal with sensor accuracy (possibly the crosstalk or ghosting issue); and on top that, some other issues they had include sensor durability, mat materials suitability, and accuracy of their tracking algorithms (which they are using some form of AI). Having prototyped a smart exercise mat around the same time they started, I can fully understand the challenges and why it is taking that long. Then again I am not sure it is worth all that effort. Personally, I think that simply relying on a pressure sensing mat to monitor and give (technique) feedback on yoga poses (or any exercises) has its limitations. Adding camera tracking (possibly utilising the camera on the tablet) might help. That saying, it is not stopping others from developing similar products as seen in this video.

Smart Insoles

Smart Insoles or Instrumented Insoles are essentially pressure sensors made in the shape of a shoe sole. The sensors are usually made in a similar fashion described earlier. Most of the Smart Insoles are also built with IMUs so that it adds a bit more context to the pressure data such as whether the wearers are standing, walking, running or jumping. The greatest advantage of Smart Insoles is they allow feet pressure mapping and measurement on-the-go. Things like continual gait analysis and activity monitoring, and it even has medical application likes foot ulcer prevention and falls prevention.

Source: Footlogger.com

There are a couple of shoemakers that designed their shoes with the Smart Insole embedded within the shoe like the Altra IQ for running and the Iofit for tracking golf swing stance. The good thing about them is they have designed everything to fit properly into a shoe, made for a specific function. So users don’t run the risk of their Smart Insole not fitting properly into their shoes and collecting inaccurate measurements. On the other hand, users are restricted with specific shoes for pressure monitoring or activity analysis. But at the end of the day, the pros and cons are really dependent on the individual.

Brief Summary

Going back to the question: “Do Force Platforms, Pressure Sensors and Smart Insoles do the same thing?”; there are some things that they are all capable of performing (e.g. gait analysis), but they all do it in a different way. Also, there are certain measurements or monitoring that are unique for each sensor. Here’s a simple table that sums it up:

Sensors	Measures shear force	Measures Pressure	Doesn’t require rigid mounting	Portable	Tracks Motion
Force Plates	✔	✔	X	X	✔/X
Pressure Sensors	X	✔	✔	✔/X	X
Smart Insoles	X	✔	✔	✔	✔

More about Smart Insoles

Personally, I feel that Smart Insoles is a great idea, with many useful applications in sports and health. Over the last few years, there has been an increase in research and development in this area with many patents generated in the process; and companies around the world have come up with commercial products around the concept of Smart Insoles. It is definitely still in its early stages and I am not sure if it has even reached Early Adopters yet. Sadly, one company that I followed (Kinematix) has already closed shop due to a lack of funding. Perhaps it is ahead of its time like the adidas intelligent running shoe with intelligent active cushioning. Nevertheless, I believe the potential (of Smart Insoles) is there and I think targeting specific niches/problems will probably have a better outcome than designing for a generic application.

If you have an idea or project needing a smart insole or custom pressure sensor, feel free to contact us or leave a comment. We might be able to help you with it or at least point you in the right direction. As always, thanks for reading!

This post also appears on sportstechnologyblog.com: link.

Accelerating Sports Technology Development And Innovation

Posted on April 14, 2017 by Julian Chua

Roughly 4 years ago, I wrote a post about crowdsourcing sports innovation – how sports companies and organisations were inviting people with ideas to step forward and pitch their innovations. Fast forward to 2017, the ways of generating new sports tech ideas have grown and evolved. From sports hackathons to accelerators, incubators, and Meetups, and online communities and invite-only/secret-squirrel investment funds or a mash-up of 2 or more of the above. I am definitely no expert in this area but based on my very limited experience, here’s a look at a few of the possible ways to accelerate sports technology development and innovation.

Hackathons

One way of defining hackathons* (from HackathonAustralia) is this: “Hackathons are competitions that challenge people to create something over a set time period using technologies.”. So in the case of a sports hackathon, that “something” created would be an innovative sports tech solution that meets an existing need/pain. It could be a hardware solution or a software solution or both.

[Themes] Depending who is organising or sponsoring the hackathon, events could have a specific theme/focus like the Western Bulldogs hackathon that provided participants with their athletes’ GPS data to do further analysis or the Future Of Sports Tech Hackathon by Enflux that allowed participants to use their motion capture technology or the Hack4Sports that had a focus on building sports tech startups.

[Needs Assessment] Whichever the theme, the participants would require some guidance/directions on real needs vs good-to-haves. That’s where industry experts and end-users (sports clinicians/analysts/coaches etc) who are at the event, can offer that perspective. This could be through talks or interactive workshops on specific areas such as improving performance or injury prevention or increasing participation etc.

[Forming teams] Following that, teams need to be formed to design the solutions. Some participants might have already formed teams prior to signing up to hackathons. But it is quite common for people to rock up by themselves. So hackathons might dedicate a session for team-forming. Typically people who have a passion in the same area would team up. Other than that, it is also helpful to have a good mix of hackers, hipsters and hustlers in the team.

Hustler, Hipster and Hacker

[Pitching Comp] Most hackathons involve a pitching competition which means the solution (created within that 1 or 2 days of hacking) has to be validated with real life users/customers and has a potential market fit. The team with the winning pitch usually wins something that can help them take their idea further. That could be prize money or often they get to be part of an accelerator program to develop that Lo-fi prototype into a minimum viable product (MVP). Else they at least have bragging rights.

[If you are interested in a sports hackathon, please complete this SURVEY]

Meetups

Sports Tech Meetups (literally on the Meetup site) are to some extent scaled down versions of hackathons and/or pitching competitions. It is usually a local group of sports tech-minded people getting together once in a while to do stuff such as pitch nights or show-and-tell or have people already in the industry sharing their insights and experience. There are no fixed rules and format which makes it quite casual and there are no barriers to joining a meetup other than geography. All you need is an interest in sports technology.

[Here’s a couple of examples: Melbourne Sports Analytics Meetup, Seattle Sports Tech Meetup]

This makes Meetups a good platform for people who are new to sports tech to come explore the field, network and learn more. It is also good for people who have developed a concept or MVP to come and get feedback from others (through pitch nights or show-and-tells). The next steps for these people could be to take part in a hackathon or join an accelerator program or incubator.

Online Communities

I believe this is quite plain and doesn’t require much explanation. There are quite a number of online platforms that allow people with an interest or a stake in sports technology to be a part of. From Google Groups to LinkedIn Groups to Facebook Pages. But what I observed (at least on LinkedIn Groups) is that there are very little open discussions within the groups/pages. In most cases, article posts get “Likes” or 1 or 2 Comments. Sometimes the posts are just companies trying to promote their products and services which often gets no “Reactions” whatsoever. So I am not sure if these groups are any good at promoting or even accelerating innovations in sports tech.

There is another online platform that has been growing in popularity (in the last few years) especially in the startup community – it is an invite only platform called Slack. Basically, it is meant to be an internal chat system for team members of an organisation to have work/project discussions. But one sports technology startup group that call themselves Starters decided to jump on this platform and allowed anyone who is in a sports tech startup (or trying to build one) to sign up to be part of the group. Though there is a fee to get in, it’s mostly to ensure that only people who are seriously interested join.

But what is happening within this Starters Slack group is quite phenomenal. Ideas are exchanged, there are open discussions, Ask Me Anything (AMA) sessions, connections and introductions are made online, followed with meet-ups in real life, actual events (hackathons, accelerator programs & meetups) are organised and promoted, and I am sure there is more happening between individuals through direct messages (DMs). What’s amazing is that though it’s mainly based in the US, there are individuals and companies participating from all over the world.

Starters – a global sports tech startup community

Slightly similar to Starters is a SportsBiz slack group started by the SportsGeek from Melbourne.The main difference is that there is slightly less emphasis on startups or sports technology and more on sports business in general. But the objective is not that different – to use the platform for sharing ideas, finding collaborators and opportunities, and ultimately pushing the sports industry forward.

Some Key Points

So there are a few key points that I take out of this. One of it is, we need to collaborate. No one can build anything great on their own. Not only do we need a diverse team with different skill sets, we need input from other people (locally & globally) or run the risk of tunnel vision. Secondly, competition spurs innovation. Which is quite apt since we are talking about sports technology here, where one of the aims of it is to help athletes perform better and win the competition. Lastly, none of the avenues on its own can be the be-all, end-all of this topic. Especially if we are talking about building successful long-term sports tech enterprises. People at different stages of their ideas or development would probably go through a different process. What may work for some may not work for others. We may need to change from something that doesn’t work anymore (e.g. LinkedIn Groups) to something else that does (e.g. Slack).

I know I haven’t commented much about accelerators and incubators. That’s mainly because I have not had any personal experience with them. What I do know is that you need to at least have a team (and not just a great idea) to be part of an accelerator and preferably an MVP to join an incubator.

Finally, I think for someone who: has a few good ideas, is passionate about (or has some exposure to) sports technology and doesn’t quite have a clear direction or built a team yet, a sports hackathon can be a good place to start. This is something I would like to explore a little more. So if you think the same way and would like to take part in a sports hackathon (or not), or if you have other thoughts on accelerating sports technology innovation, do help me out and complete this SURVEY or leave a comment or drop me a message on Twitter or LinkedIn. With that, thanks for reading!

This post can also be found here

*Hackathons have also been known as hack days, hackfests, startup weekends, makeathons, design-athons etc.

Tracking & Managing Anxiety in Athletes Using Wearables

Posted on August 31, 2016 by Julian Chua

The 2016 Rio Olympic games as with the previous games was a great platform for many tech companies to showcase their latest developments. There are radar and camera technologies that capture motion/biomechanics of an athlete on the field and in the pool. There are wearable devices that (also) track motion plus monitor physiological parameters 24/7. They aim to positively alter athlete behaviour and optimise performance. There are also sports apparel and equipment that were designed and developed (after much R&D) to enhance athlete performance. But we will leave that for another time.

Wearables for tracking performance

Going back to wearables and tracking systems; they often look at (somewhat) straightforward parameters – joint positions, speed (or velocity), height, acceleration, impact, angles, rotation rate, heart rate, heart rate variability, sleep and other physiological stuff. Sometimes coaches and athletes only need to look at a single parameter while other times they may need to examine a combination of variables and find correlations or visualise them over time to identify trends. Some companies go further by processing the above data and coming up with (trademarked) indexes such as Player-Load (Catapult), Windows of Trainability (Omegawave) and Recovery Score (Whoop). What they are trying to achieve is break down all the data that is being collected and deliver one metric that simplifies things and make it easy for coaches and athletes to measure performance (and recovery) .

In major games like the Olympics, where athletes trained years to prepare and qualify for that one event and possibly one moment, there can be a lot of anxiety and pressure to perform. Even if all the physical preparation has been done right, the results could still boil down to how well those emotions are managed; the difference could be between a podium finish or not performing as well as expected. So are there wearable technologies that monitor an athlete’s emotions and maybe warn the athlete of dangerous anxiety levels that can lead to choking or panic?

Wearables for tracking anxiety

Turns out there are a number of wearables in the market that do that. Here are three different types:

Head-worn wearables that measure EEG signals (or brain activity) like the Emotive Insight and Muse. Although the Muse is designed as an aid for meditation and relaxation, it is basically monitoring four EEG channels to see how excited or relaxed a person’s brain is. The Emotive Insight has five EEG channels and looks at the user’s cognitive performance in areas such as Engagement, Focus, Interest, Relaxation, Stress, and Excitement. Emotive also has a higher spec neuroheadset that can look at fourteen EEG channels and goes into much more depth of what’s going on in a person’s mind and how he/she is feeling.
Emotiv Epoc+: 14 channel wireless EEG system
Wrist-worn devices that measure electrodermal activity (or EDA), blood volume pulse, skin temperature and motion; like the Feel and Empatica E4 wristbands. Based on research, measurements of EDA strongly reflect sympathetic activation which is linked to stress levels and excitement. Measuring heart rate variability through the blood volume pulse sensor also reflects sympathetic and parasympathetic activation. Skin temperature is another reliable measure of stress levels as shown in this research. Finally, motion tracking with inertial measurement units (or IMUs) helps identify the user’s activity and tries to place a connection between anxiety levels and what the user might be doing at that time.

The Empatica E4 and Feel: 4 sensors packed on a wrist device
Clipped-on devices that measure breathing frequency like the Spire. The Spire is built with force sensors; when it is secured onto the user’s waistband or bra, it detects the expansion/contraction of the user’s torso and diaphragm during breathing, thus deriving the breathing rate. Then algorithms are used to determine from the breathing waveforms whether the user is calm, tensed or focused.

Spire: Breathing frequency tracker

Most of these devices also provide an accompanying app to monitor anxiety levels, and they prompt users to meditate or do breathing exercises. On a side note, a breathing exercise for lung patients was adapted for training athletes’ breathing technique and also focuses on dealing with anxiety. Athletes could also listen to brain.fm music that either helps them relax or stay focused. In a way, managing stress levels on a day-to-day basis can be beneficial for athletes because stress levels can increase the likelihood of an athlete falling sick or getting injured, and it also affects recovery.

Emotion Profiling for Performance

On the other hand, when it comes to performing well during competitions/races, some athletes actually perform better with some amount of anxiety. In fact, different athletes in different sports may perform better at varying levels of anxiety. In other words, some athletes perform well at high levels of arousal while others may perform better at lower levels of anxiety. It’s all about finding a sweet spot. As mentioned in this article, one widely used tool by coaches/athletes to identify that sweet spot or optimal performance zone is the individual zones of optimal functioning (IZOF) model. This is a qualitative analysis approach that involves the athlete recounting the emotional experiences related to successful and/or poor performances. All the emotions are then labelled and rated as described here, and this creates an individualised emotion profile showing which emotions are helpful for performance and which ones are unhelpful. Of course, this would only work if athletes have competed for a number of times previously and came out with different outcomes (winning or losing or setting new personal bests).

Individualised emotion profiling (source: sportlyzer)

Ultimately we could utilise all the different wearables (and tools) mentioned above and somehow piece all that data together to shed some light on the inner workings of each individual athlete. Then the data could be used to “pivot” them in the optimal direction. But at the end of the day, its really down to the athletes themselves pushing hard every day and fighting battles with their body, mind and soul to get to where they would be. So let’s just salute the Olympic athletes for what they do and what they have achieved. And while we await the start of the Paralympics, I leave you with this video below by Under Armour and Michael Phelps. Thanks for reading!

Some thoughts and takeaways from #SAC16

Posted on July 26, 2016 by Julian Chua

The 2016 Asia-Pacific Sports Analytics Conference took place recently at the NAB Village. Its only the second time this conference is held and I have to say it has done really well. The numbers prove it – 865 attendees (according to the Whova app), 33 sessions that ran concurrently in 3 different rooms, 45 Speakers (all experts in their fields) representing 57 organisations, and 12 startups that pitched their innovative ideas/products/services. There was even a waitlist 2 weeks before the event. This goes to show the ~~growing~~ booming popularity of data analytics, and the potential impact it could have on the different aspects of sports.

You know it’s a serious conference when it has its own coffee cup

Unfortunately, as with any great conference where there are sessions running at the same time, people would be torn between 2 (or possibly 3) presentations they are keen to attend. Fortunately, from what I heard, videos of all the sessions will be uploaded in a few weeks and we will be able to catch up with every single one that we missed. Just keep a lookout on the conference website here. In the meantime, here are some of my takeaways from the few sessions I managed to attend.

Smart equipment:

Professor Tino Fuss presented some of the research and development that was going on at RMIT including a smart cricket ball, a smart soccer boot and smart compression garment. With the advancement of inertia sensing microtechnology and novel pressure sensing technology, sensors can be placed unobtrusively on the athlete and equipment, measuring a range of parameters at much higher magnitudes. No doubt that the sensor data that’s acquired has to be analysed to solve a problem or confirm a hypothesis. That’s where analytics play an important role. But applying the appropriate sensor technology does open up opportunities to analyse new parameters like the sweet-spot on a soccer boot that increases the chance of a goal.

Wearable tech for rehab:

Shireen Mansoori is a doctor in physical therapy who applies wearable technology in her practice with elite athletes. She presented a model where she combined physiotherapy and data analytics for athlete optimisation. She uses Catapult units for monitoring an athlete’s Player Load & Hi Deceleration efforts to find trends that lead to injury. But she also uses other wearable tracking devices such as the Misfit shine on the athletes, health/wellness monitoring apps, and an athlete sleep screening questionnaire to monitor an athlete’s sleep and daily activities. Having other forms of data paints a much clearer picture of what an athlete is going through, and allows her to find out why the athlete is recovering faster or performing below expectations.

Video analysis & Artificial intelligence:

In cases where it is still obtrusive to place sensors on athletes (for example in swimming competitions); or where wearable sensors can’t provide specific activity/events information (for example attack, pass or steal events in hockey), sports analysts turn to video analysis/coding. However, much of the video analysis work involves a sports scientist (or two) manually tagging/coding every event during the competition. Stuart Morgan, sports analyst at AIS, talked about developing computer vision algorithms to detect patterns and features and somehow automate the tagging. But this approach (human engineered method) has lots of limitations including it being non-transferrable and not very adaptable (for use in different sports). So AIS is collaborating with researchers at La Trobe Uni to apply deep learning (using Convolutional Neural Networks) to process the video images and work out whats happening. The advantage of deep learning is that it’s adaptable and it automatically creates new features. It still has some way to go as it’s not error free and users can’t really tell what logic led to the decisions.

Stuart Morgan talking about AI in sports analytics

From elite to grassroots:

Most of the stuff mentioned above happens in the professional/elite athlete space. However there is also an increased trend of sports tech/analytics companies developing products for athletes and coaches who participate in their local leagues. Hudl‘s video analysis software was first developed for professional teams. But today, their software caters to high school teams and their requirements. They have developed mobile apps that allows video recording and editing directly from the coaches’ mobile device, and there’s even a platform for sharing videos and facilitating talent identification.

Athlete tracking wearables have also moved in the same direction. Startup companies like Essential GPS and Sports Performance Tracking have developed more affordable tracking solutions so that teams with lower budgets can also track and monitor their players. Although it seems to be purely GPS data (without motion data), and only post game/training analysis (not real-time), it is still a good start. Or maybe a simplified, cost reduced system is all that is required?

From the startup community:

So there were 12 startups showcased in the conference. Other than the 2 mentioned above, there were 4 other startups that have built hardware in areas of performance tracking, drone racing, rehabilitation, and custom protective gear. The others were mainly software based, providing services and platforms in media, news, sales, marketing, VR and team management. They have all developed solutions hoping to fill a gap identified in the sports industry. Personally I am just amazed at some of the novelty and innovation they have come up with; and as this blog post says it, they are all innovators.

Bottom line:

I think what sums up this conference for me is that sports analytics is all about adapting and innovating. Everyone in their own ways are trying to fix a problem (or come up with a better solution) or improve work flow or even create new opportunities (e.g. esports and fantasy league). But the process is never a straight line from point A to B. The solutions need to be adapting over and over (almost like deep learning). Sometimes there needs to be collaborations and sometimes the end solution needs to be a combination of solutions. Whichever the case, iterate the process as quickly as possible till an optimum outcome is reached.

@HPSportNZ Innovation manager talks about successful #innovation thru quick iterations of solutions dev #sac16 pic.twitter.com/1gsRm4mVpw

— Julian Chua (@reengineerlabs) July 22, 2016

The”one-size-fits-all” solution doesn’t work very well anymore and mass customisation is becoming the norm. As mentioned by John Eren MP and Laura Anderson during their welcome addresses, we are slowly moving away from economies of scale and towards economies of scope.

Group photo after welcome address. From John Eren Mp’s facebook page (link)

Anyway, congrats again to PSCL and KPMG for another successful event and thanks for reading!

Dealing with the Heat

Posted on November 15, 2015 by Julian Chua

A while back, I wrote a post about overheating in the iPad – how too much heat renders the iPad useless because it just shuts down. When that happens, you could either remove the iPad from an external heat source (e.g. direct sunlight), allowing it to cool passively; or apply some form of active cooling to it (chemically, mechanically, or electronically). Then once the internal temperature has dropped below the “shut-down threshold”, the iPad usually performs normally again.

Athletes can also suffer from an ‘overheating’ type of situation and in some cases can lead to hyperthermia. Due to an extended period of high intensity physical exertion, and/or being in hot and humid conditions, an athlete’s core body temperature could go up to say 40 degrees C. Lots of studies have shown that this (excessive heat) can have a negative impact on the athletes’ exercise performance (or muscular endurance) and possibly some adverse effects on certain cognitive abilities.

So how do we deal with this heating issue that affects athletic performance? On top of ensuring proper hydration and sticking to safety guidelines (mostly common sense), there are a number of cooling strategies and technologies that could keep athletes cool, which then prevents heat illnesses, and ultimately helps maintain performance.

Heat Acclimatisation

Although not exactly a cooling strategy, heat acclimatisation is a common practice for athletes living in cooler climates and preparing to compete in warmer and humid climates. The acclimatisation process might involve moving to another location with similar weather to live and train, or it could be training in an indoor controlled environment where heating and humidifiers are applied. Basically, the aim is to get the athletes accustomed to the higher air temperatures and so reduce the impact of heat on their performance. In some cases, heat chambers are also designed to be hypoxic chambers so athletes can also be conditioned for high altitudes (which would be handy for events like the 2010 football World Cup).

An example of PAFC players training in a heat chamber in UniSA (source: perthnow.com.au)

Cooling Strategies

Pre-cooling is the process of cooling athletes before performing any exercise. There is evidence to show that pre-cooling procedures benefits athletes in endurance sports, and to some extent athletes in team-sports that require high-intensity repeated sprints (study link). It was gathered from this article that whole body pre-cooling is the more effective cooling procedure compared to only upper body cooling using cooling vests such as the adidas adipower or game ready vests. Although logistically, preparing the equipment for whole body cooling may take a bit more effort, compared to just distributing a bunch of cooling vests to the athletes.

An Example of a Portable Ice Bath from icoolsport

This article looked at a half-time cooling strategy that involves getting the soccer players to immerse their forearms and hands in 12 degrees water and putting a cold wet towel (that was previously soaked in 5 degrees water) around their neck. Their results showed that this primitive active cooling method significantly reduced the athletes’ body core temperature in 15 minutes.

A Novel Cooling Tech

A company called Avacore Technologies developed a novel technology that allows an athlete to cool down by simply wearing a specialised glove. How it works relies on the fact that the palm of our hands are radiator surfaces; which means when our body temperature goes up, blood flow naturally increases through those (radiator) skin regions to dissipate heat. This is achieved through special blood vessels called arteriovenous anastomoses or AVAs.

Retia Venosa

The glove system known as Rapid Thermal Exchange (RTX) was invented by two Stanford biologists who were doing research on thermal-regulation. The system not only regulates a continuous flow of cool water through a pad (or grip/cone) which the user’s palm maintains contact with, it also creates a slight vacuum within the glove and that limits the blood vessels from constricting, which allows better blood flow and ultimately better cooling. There is a lot more explanation on their FAQ page, and links to scientific studies/evidence at the bottom of the page here. Or if you prefer to watch a video, check out this one from CNET where the presenter actually did a test herself and showed that it actually works – cooling her significantly and improving her endurance.

[A side note on the video: using an ingestible temperature sensor would have saved the presenter from that gagging experience (around 1:40 of the video)]

So not only is this glove technology keeping athletes cool and preventing diminished performance, coaches are seeing their athletes push harder and longer when the RTX is used in between training sets. The rates in gain is so dramatic that the gloves have been labelled as more effective than steroids. But even with such good reports, not everyone is rushing to purchase these gloves yet. As mentioned in their paper, the inventors recognised that there are a few barriers and one of it is people’s resistance to new views. Another challenge is to develop something more compact or even wearable, so that it increases the potential of effective application in other areas such as mining, firefighting, or emergency services.

Recently, Avacore launched an Indiegogo campaign to crowdfund their new consumer version which is just one standalone portable device instead of a few components. Looking at the number of backers, I would say it was very well received.

Different versions of the Avacore Cooling “Glove” (avacore.com)

Something for the makers and tinkers

Interestingly, someone who really liked the product but thought that the CoreControl Pro version was too expensive, decided to make a DIY version for a fraction of the price. He even made a CoreControl DIY Instructable. Based on the comments, there’s at least 2 other people who followed the instructions and built one for themselves. One other guy even made some improvements and published his own guide on how to build it.

Closer to home, a mate of mine also attempted to develop a product similar to Avacore’s hand cooling concept. One main difference is that his design does not require the use of ice and water, something that most of the methods mentioned earlier use. Instead, his entire system is electromechanical, very portable and can be easily switched between cooling or heating. If anyone in Melbourne would like to be one of the first few to trial his prototype, drop me a message/comment and I could help organise something.

Finally, with all the cooling technologies and methods out there for athletes, I think something that will really complement them, is a wearable temperature sensor (such as the cosinuss) that can constantly monitor body core temperature. That way, coaches can know exactly when to stop the athletes from their activity and stick their hand into a body cooling glove.

Versus Fitness: Developing A Smart Gym

Posted on May 4, 2015 by Julian Chua

Over a year ago, I wrote a post about developing with the Kinect and how I was working on a project that revolved around it. Fast forward to today, the project is now an officially launched gym that is also known as Versus Fitness.

What is Versus Fitness?

Versus is a system that has gamified fitness. By utilising different sensors and technologies, it is able to measure 3D motion, pressure, force, acceleration and power output of over 200 different gym exercises (and counting). With each proper repetition (or rep) that is executed, the user not only gets the rep counted by the system, a score is given based on the above measured parameters, and the score is scaled based on the user’s weight and height. In that way, 2 people of different weight and height doing the same workout can compete against each other on almost equal terms (Hence the name Versus). In case the term “wearable technology” comes to mind, no, there is nothing that the users need to wear to get their exercise tracked (maybe except a heart rate monitor, but that is purely optional). Just check out the video below.

How I got involved?

I started working on the Versus Fitness gym since late 2013 and it was purely by coincidence. Someone who knew Brad Bond (the founder of Versus Fitness) was at the RMIT Sports Engineering Lab on one of those Uni open days and he saw a novel sensor technology that would suit Versus. After a series of meetings and discussions, a research contract was set up to further develop that technology for Versus. This was partly funded by the Victorian Technology Development Voucher. At the same time, they were also looking for an additional team member to work on motion tracking algorithms. That’s where I came into the picture. Long story short I was offered a contract role on the Versus project which was partly funded by the Enterprise Connect – Researchers in Business grant (this has been replaced by the Entrepreneurs Infrastructure Programme). Kudos to Aaron Belbasis who was a key connector/initiator who brought everyone together and who was also one of the key researcher who helped develop the novel sensor tech. There’s a bit more details about the RMIT-Versus collaboration here.

What Tech are we talking about here?

One of the sensor technologies came from the research collaboration mentioned earlier. The team at RMIT calls it a “sensor-less sensing platform”. The closest thing would be Force Sensitive Resistors (FSR) like the ones from Tekscan. If you had a proper look at the video above, you will see the “sensor-less sensing platform” used in the floor exercises and some of the running exercises. Basically its a sensor that measures pressure.

There are other sensors that were developed or customised for tracking motion and a number of them are available off the shelf or at least purchasable online. In fact some of the sensors (like load cells and accelerometers) are similar ones typically used in the manufacturing, or automotive industry. A lot of custom fittings, enclosures and mechanisms were designed for the sensors before they could be installed in the gym. Majority of the design were done in-house and prototyped with the help of a MakerBot replicator.

But what really made the sensors (tracking system) worked effectively are the smart algorithms that processes all the sensor data and accurately identifies when each person is performing the exercise properly and evaluates how well he/she has done it. Initially when designing the algorithms for tracking each type of exercise, it all seemed pretty straightforward; but as things progressed, it turned out there were quite a few more considerations – e.g. filtering out “incorrect” movement data that resembled an actual rep, or profiling movement data from users of different abilities (or fitness level) etc.

Perception & Reality

Another important part of the system is the “gaming interface” or the “gaming control centre”. It is the personal trainer’s assistant. It relays to the users what exercises to do, records their performance, stores the performance data in a database, reminds the user how well they did previously (their Personal Best), manages the equipment (to some extent), and ensures that every exercise station is in sync so that the workout runs smoothly. That allows trainers to focus on one of the things they do best: ~~scream at~~ motivate people.

So with the combination of the sensors, smart algorithms and the gaming interface, this means: real-time tracking, with feedback of the users’ performance (score) or technique delivered right after each completed rep, and an overall quantified workout so users know how well they fare compared to their previous workouts (and with other users).

Future Developments?

The very first Versus Fitness gym is based in Moorabbin and that has seven different exercise stations (as seen in the video above). One could call that the full Versus experience. There are a number of possible developments in the pipeline. One is the development of new exercise stations to increase the type of exercises that can be tracked. Also, there are possible opportunities to customise the system for the elite or professional athletes, or even rehabilitation applications. Something that is definitely in the works is a “multi-station” concept – a single exercise station that has several sensor solutions allowing tracking of a few different types of exercises (e.g. dumbbell, kettlebell & floor exercises). This significantly reduces the footprint of the equipment and would suit small gym spaces. In fact this is currently on trial in a gym somewhere in Australia, and depending on how things go, you might start finding the VS logo in many more places!