Case Study: Developing a punch tracker for boxers
May 9, 2017
Hykso is a new venture founded by CEO Khalil Zahar, who has a master’s degree in MEMS, and is also a successful boxer who trained with the top coaches in Toronto. Zahar reached a high level of proficiency through his training, so high in fact that it became difficult to discern further improvements in his performance, and so came the idea for a device that could measure a boxer’s punches with a high degree of precision and track his or her progress in training.
Hykso was formed to develop that product, and the company is now a hot young start-up in California’s wearable technology sector.
Hykso’s product is a wrap that the boxer wears around the wrist, with sensors that detect the force of the physical effort in each blow, then the data from the punch speed and punch count are combined to create an accurate measurement of the blow.
The punch tracker was a particularly difficult product to develop. The first challenge was to develop the algorithm that calculates the data. It is far more complex than just a punch counter. As with a lot of wearable technologies, a boxer is always on the move, so the product’s sensors have to measure the super-acceleration of the punch – most wearable devices move far more slowly. Each Hykso unit contains two sensors and two antennas to track the movement.
It’s also in the nature of boxing that the movements are not clean. The algorithm has to determine what comprises a punch and what does not, and the device needs to be mechanically strong, which is a challenge for such a tiny device.
To measure the speed and power of a punch, it pinpoints the position of the device precisely in 3D free space and uses advanced statistics to determine an accurate measure of the speed. The company uses its mathematical capabilities to achieve this feat of calculation. Then the data are translated into results that can help a coach to train better boxers.
Incorporating the antennas into the design was another challenge. Hykso was aiming for a range of 10m, but the first antenna tried always seemed to be out of range. Then when the antenna seemed OK, performance tailed off when the product was worn on the wrist, and it was not clear why. Electronic designer Alex Marcotte realised that the human body could absorb radiation and decided ro look for a small antenna with a long range.
It was at this time that Hykso first talked with the people at Arrow Electronics who introduced them to Antenova. Antenova’s local technical support team in Northern California helped with the selection of a different antenna, and a better PCB layout that would achieve a longer range.
The Antenova team explained how the antenna works, and how the energy dissipates away like a car headlight reflecting away from the car. The space for the antenna on Hykso’s PCB was very small, its position was restricted, so it chose the company’s chip antenna, Comata, which measures 12.8 by 3.6 by 3.3mm.
With such a device, there was no way of estimating its range – the only way was to build one and test it. A few questions arose. How would the board perform with the hand-loading effect? Would the antenna perform any differently on the left or the right corner of the board? With advice from the technical support team, and using the guidelines on Antenova’s datasheets, the board was re-designed, and the Gerber files were forwarded to Antenova for testing.
The tests had to replicate the sensors as they would be used in situ inside the boxing wrap and a boxing glove, so Antenova used a phantom arm. The firm’s standard tests include a matching service, 3D gain patterns and an efficiency test. These are all part of the process of fine-tuning an antenna. The tests were completed very quickly and the device immediately achieved a range of 50 per cent further than with the previous antenna.
“I am not really familiar with RF, so the results from this antenna seemed like pure magic,” said Marcotte. The initial tuning of the antenna was organised through Arrow Electronics.
This is the first product of its kind in the market. The beta stage, where a number of coaches and fighters, including some Olympian boxers, tried it and gave their feedback, is complete, and Hykso has invested time in perfecting the product. It is now ready to ship the first few thousand deliveries to customers this year.