Multi-Room Intercom

The client has been designing and supplying products to enhance the independence and quality of life for people with special needs for more than forty years. They are regarded as leaders in Electronic Assistive Technology (EAT), Alternative and Augmentative Communication (AAC) and Environmental Control Systems (ECS) and are approved suppliers of Electronic Assistive Technology products and services to the NHS. 

The brief was to work alongside the clients own software and electronic design team and to develop a mechanical design for an entirely new multi-room intercom and door release system. The key requirements were flexibility, portability and ease of installation. The user unit had to mount on a wheelchair or in its own docking station. 

The system consists of three modules. User Intercom unit, External Intercom unit and a Door Entry Control unit. Each has different requirements such as weather proofing for external use, ease of wiring and ruggedness to resist deliberate attack. The functions are controlled via infrared, radio transmitted from ECS units or by using the integral push buttons or an external switch input. The project was strongly supported by the client who contributed experience gained from evaluation of previous models. 

The first stage was to prepare a full specification for the product including a user methodology. This stage was followed by an extensive concept design stage where several different internal arrangements were explored with the client to achieve a compact design. Once the build was agreed, drawings of the PCBs were issued to the clients own engineers for simultaneous development. The external enclosure was developed using 3D CAD and several concepts presented as 3D visualisations. 

The project required close collaboration with the clients own engineers to resolve issues with component placing as they developed the PCBs. The final design was achieved using rapid prototypes and prototype PCBs prior to commissioning all tooling from 3D data and control drawings.

Rapid prototypes were invaluable in resolving issues of audio separation and the design of the wheelchair and docking station mounting mechanism which was engineered for robustness and ease of operation.