Design and build stand-up and walk aid - smartChair
Background
Ageing is a process that affects us all. In particular, when old age strikes, many of us are affected with various health issues such as arthritis, continuous back ache, knee joint pain, etc. This renders one to rely on another person for help in standing up and sometimes also walking. In the UK, around 10 million people have arthritis. And similar would be true for other illnesses that affect day-to-day activities such as standing up and walking. A device that can bear some of their body weight and support in getting up from their chair, bed, or sofa from sitting position to standing position, would greatly help in improving their well being. The same device should be able to provide support during walking to improve its usability.
In this project, my aim is to design and build a lightweight and easy to use device, a smartChair that would support sit-up by providing power assistance. The additional power will only be assistive power (similar to power assisted steering in vehicles) rather than resisting their motion, to ensure no unnecessary strain development in human body. Moreover, in standing up position, the smartChair would become slender (and stable) such that the person can use it as a walking aid. It would be beneficial to have the 'summon' functionality to call the smartChair to desired location (within indoors) so that the person can use it when their helper is not available and stored out of the way not needed. However, this may not be achievable within the project time frame. As a minimum, a webcam would be installed so that the chair can be driven by the user remotely to bring it closer to them. Consequently, the smartChair should also be able to climb the stairs up and down.
Arduino Nano 33 IoT will provide connectivity of this smartChair to the user via an application on their smartphone device, as well as positioning and orientation of smartChair by its onboard IMU. Furthermore, Bluetooth will be used for localising chair’s position indoors. The concept is shown in the picture below. However, the exact design might differ in terms of mechanical design which will emerge from the research undertaken as mentioned below.
Materials
- For mechanical build, the seat will be made from wood whereas the frame will be made from aluminium or other suitable metal. The chair would be optimised as much as possible in terms of its weight and size whilst preserving structural requirements.
- I have dismantled an old non-working office printer and some home printers which would be a source for BLDC motors with gear boxes, bearings, linear and rotary encoders, motor drivers, various proximity detectors, and various discrete electronic components. Further needed parts will be sourced accordingly.
- A suitable battery and its power management module will be sourced.
Testing
- Development testing will be done along the development and build stages as appropriate.
- Application test will be first performed by providing forces to seating surface, manually via hand pressure, etc., to avoid any mishap. Once confident on the functionality, the chair will be tested by a healthy person under supervision. The safety of the subject would be kept paramount at all times.
Expected outcomes
A functional smartChair that can be used for power assisted stand-up and provide support in walking.