Tracking the wave of success for Team GB's swimmers

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Training sessions for Team GB's swimmers have been getting a helping hand from a new system incorporating cutting-edge movement tracking and sensor technologies.

From starting dives to tumble turns the state-of-the-art coaching aid is the first of its kind to be able to track movement wirelessly through water.

The system has been developed at Loughborough University's Sports Technology Institute in conjunction with British Swimming, with funding from the EPSRC. Other partners are UK Sport, Imperial College London and Queen Mary University of London.

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[Narrator]

Tumble turns, dives, glides and stroke technique. Every aspect of movement is crucial for elite swimmers. For their coaches, training athletes for a sport where most of the activity takes place in water is obviously a challenge. However, a pioneering wireless tracking system developed by UK researchers has been helping some of team GB's swimmers prepare for London 2012. It brings existing sensing and motion tracking technologies together into one system. Crucially, the researchers have also developed revolutionary technology that enables data to be transmitted wirelessly through water. The research has been taking place at Loughborough University led by Paul Conway, Professor of Manufacturing Processes.

Professor Paul Conway, Professor of Manufacturing Processes Loughborough University [PC]

This came about really from a challenge from British Swimming who had tried a number of times in the past to understand a bit more about how their swimmers performed and how they might measure their performance. Because a swimming pool is quite a challenging environment - there's lots of water and the human body is mostly water - it makes tracking things wirelessly very, very difficult. And doing things like measuring in real time, things like speed, number of strokes, how they move in the water and how they turn, or how they start is very difficult because there's a lot of water. And that's a noisy environment in terms of the signal noise and the amount of interference you have.

[Narrator]

Professor Mike Caine is Director of Loughborough's world leading Sports Technology Institute. Along with Paul Conway, he explained more about the new system.

Professor Mike Caine, Director of Loughborough's Sports Technology Institute [MC]

It's a small box of electronics that's worn on the small of the back, and sends wireless signals that are picked up by a laptop receiver on the poolside. The laptop then displays the various measures that are of interest to the athlete and the coach.

[PC]

And then on each end of the pool, we have a pressure mat essentially stuck to the wall. It's a very thin pressure mat which, when you touch it, measures pressure, essentially force. Also, we've got some underwater high speed video cameras and on the swimmers we have some LED markers which are quite unique - waterproof markers that they wear on their hip.

[MC]

The idea was that we would utilise technology. Things like accelerometers, gyroscopes, motion tracking techniques that we'd either directly developed ourselves, within the research group, or we were taking those technologies as they were emerging elsewhere and integrating them into a package that would support the swimmers and their coaches. Effectively, an accelerometer allows you to derive speed/velocity. Of course, you can also derive acceleration, so the rate of change in velocity and that can be just as interesting. A gyroscope is important because as the swimmer turns at the end of each length, you're able to characterise the position through the tumble turn and you can then analyse the technique. We can then look at the biomechanics or the kinematics, the human motion relative to their position in 3D space. And it's important to understand the orientation of the athlete so that you can make some meaningful analysis from those data.

[Narrator]

Innovative projects underway at the Institute's research labs range from the development of new materials for sports footwear to tailor-made handle grips for rackets. Paul and Mike say a significant aspect of this research has been developing a way of transmitting wireless signals underwater.

[MC]

Wireless technologies are part of our everyday life now, but you'll appreciate that the vast majority of transmissions are through air. There are very, very few everyday applications that require transmission through water and so it's not surprising that the transmission of wireless information through water has received less attention. And that really meant that all of the everyday commercially available protocols just didn't work in that environment.

[PC]

I can disclose that we've optimised the frequencies of our transmission, the antenna design on the swimmer and also on the base station beside the pool and the arrangement of the equipment on the swimmer and beside the pool. Also we have put intelligence in the software so it knows what's happening and can interpret if a signal drops out, what to do and how you can account for that. Building redundancy as well, so we can still get the data if we lose it for a few seconds. Putting that together with other things around the pool such as video, force sensors in starting blocks, pressure pads at each end of the pool for measuring the turn, into one integrated system is the unique thing. You can actually watch it on high-speed video and also see what's happening with the inertial sensors showing in real time so each frame of the video is synchronised with what's happening on all the other sensors. And that's probably the key step, bringing it altogether, integrating the various sensor modes.

[MC]

So, we were having to genuinely invent new ways to transmit data that would be successful whilst in the pool environment. I can't describe exactly how we have done that because it is subject to a patent - it is an inventive step and it is one that has commercial value. But hopefully you get a sense of how different water as a medium and air as a medium are and the need for a radically different approach to the same problem.

[Narrator]

The new system enables coaches to give much quicker feedback to the swimmers.

[PC]

They will see simultaneously on the computer screen the video as well as the data that's coming off the node, synchronised. They'll also see from the turn, the data we're getting from the pressure mat presented in a way that it's understandable. In terms of the time, a nice colour map of when the feet touch the wall, how hard they touch the wall and how long they're on the wall - some will bend their legs a bit longer so they're pushing longer on the wall. The coaches will also see some of the measurements we get from the node the swimmers wear on their backs. We can pick up stroke rate, the velocity, how quickly they turn, how quickly they tumble in almost real time.

[Narrator]

Beyond swimming and London 2012, the system is already being looked at by industry to track components in factories for instance where there are wet and noisy environments. The project is supported by the Engineering and Physical Sciences Research Council (EPSRC). Other partners are British Swimming, UK Sport, Imperial College London and Queen Mary University of London.