We worked with medical device company Ingeneus and the Royal Eye and Ear Hospital in Melbourne, Australia to develop a sterile low-cost tonometer to measure eye pressure. Tonometers are traditionally complex devices used by ophthalmologists and optometrists to detect eye conditions such as glaucoma.

Ingeneus wanted to develop a low cost single use tonometer that could be easily used by primary health care workers to measure eye pressure.


18 months

We researched potential mechanical and electronic systems for the tonometer design. We measured the performance of existing professional gold standard tonometers to use as a benchmark through the development process.

Our team pursued a mechanical design option and developed a precision micro-moulded spring mechanism that provides the sensitivity and accuracy required by applying ultra-low pressure on the surface of the eye.

We created high-precision prototype parts and tested and refined the tonometer’s performance on ocular models. The tonometer was tested by specialists at the Royal Eye and Ear Hospital. outerspace designed the tonometer so it can be used on a patient when they are upright or reclining.

We engineered a micro-moulding has a counterbalance element that finely controls the pressure applied to the eye. The tonometer is small and lightweight. A plunger activates the micro-moulded spring, when applied to the eye, which in turn activates the indicator needle. A disc behind the plunger wets out on contact with the surface of the eye to indicate to the operator that the tonometer is in the correct position for a reading.

We designed an easily viewed traffic light system colour band display where the needle indicates the pressure level. Green indicates normal pressure, orange, is medium pressure and indicates a need for further investigation and red is high pressure which indicates that the patient needs urgent medical attention.

We refined the ergonomics of the tonometer to make sure the device is easily and safely used by untrained medical operators.

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Brody Payne

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