The Force Shoe by Xsens

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

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 PlatformsPressure SensorsSmart InsolesSummaryMore 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.

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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 JournalSports 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.

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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).

Single Sensor Nodes Vs Arrays 2

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.

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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!


Other related articles:

Accelerating Sports Technology Development And Innovation

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.

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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.

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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.

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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.

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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.

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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. So this is something I would like to explore a little more. 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!

Other related readings:


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

A new Journal, the rise and rise of sport technology

journal of advanced sport technology.jpgCongratulations to Abbas Meamarbashi and colleagues on the founding of the Journal of Advanced Sports Technology, servicing the middle east as well as the international community, it so exciting to see it developing everywhere. Sports Technology really has exploded in the past decade becoming a mainstream role in many sporting organisations and popular through consumer devices. It also offers unparalleled opportunities for sports scientists and allied health researchers and professionals to ask and answer many more interesting research questions that can ultimately benefit humanity.

 

Its a delight to see Griffith SABEL director David Rowlands amongst the editorial board too. Thanks for the invitation to publish the guest piece “Wearable Technology in sport, a convergence of trends” as well. I quite enjoyed exploring the underlying trends that have created the opportunities today and some pointers for the way forward.

 

You can read the entire first issue here

Design Tech and coding – How I got owned by high school students!

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Joining the Cavendish Road SHS year 10 coding class with Mr. Thomson

Well I got to be a school boy again earlier this week. Having had something of a collaboration with the Head of Business and Technology – David Thomson at Cavendish Road High School I was delighted to be invited to share some of of the joys of working with coding, sensors and more recently wearable technologies with STEM students. Sport is a great hook for engagement and SABEL’s success in a wide range of elite sports made for some great conversation. It was a great opportunity to interact with his Yr10 Digital Technology and the Yr 11 Technology Studies students under the watchful eye of Don Markovic. I was impressed with the coding abilities of the students and the delivery of the programme though a mixture of fun, experimentation to build real skills.

The Tech Studies students who are undertaking a project of their choice were an inquisitive bunch often getting the gist of why we might want to measure stroke rate in a rower or jump height of a snowboarder and asking so many insightful questions. Under Don’s tutelage I was able to talk about the importance of lowing project risk, getting that early win (which we call MVP- minimum viable product in the game) rather than creating the dream feature rich technology straight up. I’m looking forward to seeing how their projects progress over the break and through term 2. Well done Cavendish Rd SHS I could clearly see where their motto of tradition meets innovation at work.

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Talking about the value of iteration in the design and execution process

This article also appears as an Advance Queensland Community Digital Champion article

Sport 2.0, where are we heading?

sport 2-0 andy miah.jpgSometime ago I had the opportunity to review an interesting book for MIT press entitled SPORT 2.0 with a complimentary copy turning up in the mail just recently. As someone working in advancing the use of technology in sport this book provided a refreshing viewpoint of what is happening from a grander perspective. It speaks to the way we think and do sport as the world changes before our very eyes with almost no aspect of sport left untouched. In my own little niche it reminds me of Porters work for HBR on Smart devices (How smart connected devices are transforming competition). Andy Miah, the author takes us on a tour deforce of what we might think sport is through looking at what games are culturally as well as in the more traditional sporting context. He considers Sport 2.0 in the context  of the digital environment, gaming and augmented reality as progressive and at times disruptive innovations. The history and ensuing evolution of the Olympic games makes for a very interesting case study and is a major focus. An entire section of the book looks at the development of the games in modern times with the influence of media, social media, citizen journalism and what mobile technologies are doing in this arena. If your so deeply into your sport or technology such that you can’t see the wood for the trees this one might give you a grander perspective, all for not much more than a paperback  price.

https://mitpress.mit.edu/books/sport-20

@andymiah

# Sport 2.0

iMOVE CRC bid success

imovecrc-logo-260.pngEarly last year SABEL Labs and colleagues were pleased to work with several Universities in the preperation of a CRC bid, the iMOVE CRC. Happily the bid was successful and we congratulate Dr Jim Lee of Charles Darwin University  for his efforts in leading their institutional success. iMOVE CRC is focused on intelligent transport systems and cuts across almost every facet of Australian life.

Whats that got to do with Sports Technology you ask? Well we reckon wether two legs or four the technologies are about the same and we can apply what we know about human locomotion to that of cattle as they make their journey from the paddock to the plate. A happy cow, that grazes just enough, is great for the Australian economy and given that 80% of export cattle pass through the port of Darwin there is a natural nexus there. Of course this is just the beginning as the integration with other parts of the value chain lead to some quite exciting analytics, fusion of data and applying our wireless technologies in new and interesting ways.

Looking forward to what comes next Jim!

Heres the press release in full!

MEDIA RELEASE  (from http://www.imovecrc.com )

$55 million federal grant for ten-year intelligent transport R&D centre will deliver better transport systems for Australia 

More productive and safer transport systems country-wide are an important step closer with today’s announcement that the federal government is supporting a new intelligent transport cooperative research centre (iMOVE CRC) with a $55 million R&D grant.

The iMOVE CRC has been in development for over 18 months and is strongly supported by industry, technology innovators, state road authorities, federal and state government departments and industry associations. These partners are complemented by Australia’s best research talent in fields relating to the development of intelligent transport systems.

The centre’s establishment is well-timed due to the challenges currently faced by Australia’s transport systems and the rapidly evolving development of technologies and business models that can help solve these issues.

“Transport is the backbone of our economy. As a country we will fall behind if we cannot move our people and goods effectively and efficiently,” says bid lead for iMOVE CRC, Ian Christensen.

“Our roads are congested and our transport systems are not co-ordinated and it’s getting worse in many cases. The establishment of the iMOVE CRC gives us an immediate opportunity to tackle this situation, by harnessing the power of ‘big data’, developing smarter solutions and engaging with the community to trial and deploy new technologies.”

The CRC funding and ten-year timeframe will enable the 46 partners to develop technology outcomes that will benefit the whole of Australia. It will deliver better options and experiences for individual travellers, much-needed productivity improvements in logistics and access to new markets for business.

Says iMOVE CRC Bid Chair, Ian Murray AM, “As a country, we lose around $16.5 billion a year because of congestion. When you also factor in the human and financial losses due to accidents, we are looking at a phenomenal social and economic cost. We will now have the technology and smarts available to significantly alleviate these problems.

“The iMOVE CRC has a research program and experienced people ready to start work immediately. I am tremendously excited by the opportunities we have in front of us with this funding.”

The introduction of connected and intelligent transport systems also requires national coordination mechanisms. The iMOVE CRC will play a role alongside other national bodies in assisting states, territories and peak industry bodies to collaborate and deliver cohesive national outcomes.

“The current explosion of data, the computing power of mobile phones, and the increasing automation of vehicles creates a vast range of opportunities to improve the range, safety, convenience and effectiveness of peoples’ travel options. Mobility and transport is one of the most exciting and dynamic aspects of urban and economic development. With its broad range of partners the iMOVE CRC will enable Australian organisations to develop world leading products and services.

“As well as with our partners we will be working in consultation with numerous other stakeholders, such as the Australian Logistics Council and the National Transport Commission. This will enable us to get the best possible outcomes for Australia,” says Mr. Christensen.

MEDIA RELEASE

“We are eager to get things happening
and look forward to working closely with all our partners and stakeholders over the next ten years.”

About iMOVE CRC 

The iMOVE CRC is a new national intelligent transport R&D centre funded through the Co-operative Research Centres programme. It is supported by 46 industry, government and research partners including the federal departments of ‘Industry Innovations and Science’ and ‘Infrastructure and Regional Development’, state road authorities, retailers, logistics and insurance companies, technology developers, automobile clubs and many of Australia’s top universities.

The ten-year centre will undertake industry-led research that uses emerging technologies to improve Australian transport systems nationally. It will deliver fast and predictable freight systems and enhanced mobility for Australians on the roads and public transport.

http://www.imovecrc.com 

Contacts 

Ian Christensen, Bid Lead

ichristensen@imovecrc.com

0411 276 104

Jacqueline King, Bid Secretariat jking@imovecrc.com
0404 045 293

Congratulations James Lee

jimssportslab-smallCongratulations to our SABEL NT director James Lee (and founder of Jim’s Sports Lab) on his recent promotion to Senior Lecturer at Charles Darwin University and recent publication.

Dr. Lee has never been shy to follow his passion for sports technology a journey that has taken him to Japan for a year with Ohgi laboratory, and several teaching and research positions at a number of leading Austrlian universities. Since landing at Chares Darwin university just a few years ago he has transformed their teaching programmes through the adoption of online and social media technologies to create a more engaging programme, led several research initiatives to help solve problems unique to the Northern areas, coordinated the areas participation in a CRC bid (fingers crossed) and continued to collaborate widely.

Recently this has also leading to a publication on cloud based wearable sensor technologies and data analytics platform, as a partnership between SABEL Labs members and the Kanoya National Institute of Sports and Fitness.

An Architectural Based Framework for the Distributed Collection, Analysis and Query from Inhomogeneous Time Series Data Sets and Wearables for Biofeedback Applications

James Lee 1,* David Rowlands 2, Nicholas Jackson 2, Raymond Leadbetter 2, Tomohito Wada 3 and Daniel A. James

Abstract: The increasing professionalism of sports persons and desire of consumers to imitate this has led to an increased metrification of sport. This has been driven in no small part by the widespread availability of comparatively cheap assessment technologies and, more recently, wearable technologies. Historically, whilst these have produced large data sets, often only the most rudimentary analysis has taken place (Wisbey et al in: “Quantifying movement demands of AFL football using GPS tracking”). This paucity of analysis is due in no small part to the challenges of analysing large sets of data that are often from disparate data sources to glean useful key performance indicators, which has been a largely a labour intensive process. This paper presents a framework that can be cloud based for the gathering, storing and algorithmic interpretation of large and inhomogeneous time series data sets. The framework is architecture based and technology agnostic in the data sources it can gather, and presents a model for multi set analysis for inter- and intra- devices and individual subject matter. A sample implementation demonstrates the utility of the framework for sports performance data collected from distributed inertial sensors in the sport of swimming.

You can download the full version Here PDF Version: http://www.mdpi.com/1999-4893/10/1/23/pdf