"Up until now the pool environment with the swimmer moving through both air and water, and splashing and bubbles, has made it difficult to see what is going on to optimise a swimmer's performance," he said.
"Encapsulating the printed circuit board of the IMU in waterproof materials opens it up to all sorts of new applications."
The device creates no drag and would enable swimmers to recognise fluctuations in speed and the orientation of their body, Besier said.
"As you go through the stroke cycle, you have a burst of speed but then you slow down. When you get fatigued you get different performances."
Inertial measurement units (IMU) developed by Thor Besier and Mark Finch.
The development of the waterproof sensors was being carried out with funding from the Australian Institute of Sport (AIS).
The AIS were solely interested in the gains for its athletes, not in owning the intellectual property, Besier said.
"They haven't cared about the commercialisation aspect. They just want something that will help their athletes and they leave the IP to us."
Besier and Finch have formed a new start-up company called IMeasureU to commercialise the tiny units.
"We'd like to have something you could buy by the end of the year. We'll test it with them (AIS) and their swimmers will use it, and if they like it we might push it out ourselves or find a partner to do the path to market."
The pair aimed to develop a Bluetooth version which could communicate with a smartphone.
They intended to create other sensors which measured the number of strokes taken, and a software program that integrated both video and the IMU data.
Besier said the IMU would in the future be just as applicable for use in medical research and other sports.