Positioning Alert

Project  / Project number: CB1818  /  Status:

Positioning Alert 1

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The challenge

The client, who has cerebral palsy, did not have the core stability to maintain an upright posture whilst seated. This resulted in the client overcompensating by leaning heavily on her left forearm, placing excessive load through the left shoulder. The client was thus concerned about the long term impact on her shoulder joint and the other knock-on consequences of sustained poor posture.

The challenge was to create a device which would alert the client to poor posture – leaning excessively on her left forearm – and provide a suitable stimulus to encourage the client to maintain better posture. The solution had to be sufficiently sophisticated that the client was able to place a normal load on her left arm and would only be alerted if a suitable threshold was crossed. The initial client meeting revealed the following requirements for the project/solution:

• Investigate and quantify load threshold above which the client should be alerted
• Sense excessive load placed on the underside of the left forearm
• Provide discreet stimulus to alert client to poor posture
• Suitable for all scenarios where the client may adopt a leaning posture
• Comfortable to interact with, ideally being ‘invisible’ when correct posture adopted by client

The solution

A lightweight, rechargeable electronic armband which produces a sound when it detects that the user is leaning continuously with a pressure above a threshold value for longer than five seconds. The incorporation of a programmable microcontroller enabled bespoke threshold values for leaning pressure and duration to be set, reducing the risk of the device providing false alerts.

The device consists of the following components:
• Force Sensitive Resistor – thin membrane which acts as the pressure sensor
• Arduino Gemma – miniature wearable microcontroller board
• Software
• Rechargeable battery
• Recharging board
• Buzzer
• Armband

The benefit

There are a few key ways in which this project has benefited the client in the short term and will hopefully provide significant benefit long term.

During the course of this project, the process of engagement with the panel has provided the client with greater motivation and focus to make other positive changes. A clear example of this being a subsequent project that the panel has undertaken for this client to make a lightweight mobility scooter seat which is easier for the client to lift whilst assembling/disassembling the mobility scooter. Therefore, as well as providing an alert to poor posture and excessive joint load, we have tackled another source of high strain which was causing the client great stress.

In the longer term, the leaning alert device will avoid the client placing excessive load on her left shoulder joint, thus hopefully improving the long term health of her left shoulder. Moreover, as the client is encouraged to adopt a better posture, it is hoped that the clients core strength will increase, providing her with the confidence and motivation to take other measures to improve her general health – such as once again going to the gym, something which the client is regretful she no longer does.

Finally, the challenge of poor posture is not limited to the client of this project. The panel believes that this solution, which is relatively low-cost and simple in its final architecture and programmable to be bespoke to each end user, could benefit a lot of people suffering with the impacts of poor posture.

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