Orchid Technologies was approached by a leading medical device company to take-over the electronics design of their cough-assist machine. In development for three years, our client’s original design team got boxed in through a series of poor architectural choices.
Orchid studied and reevaluated the entire electronics design. Making radical changes, we executed the delivery of working prototype units in four months. Cough-assistance requires the production of pressurized air. That air pressure must be controlled with great accuracy throughout the cough-event. During the cough-assisting process, airflow through the motor system changes rapidly. These changes cause large, step-function changes in the motor’s load.
To function correctly, motor control electronics must rapidly adjust to these rapid changes in motor load. PID motor speed control with advanced feed-forward control techniques permits precise motor speed control. The design was divided into three different circuit boards: the main controller responsible for the keypad input and driving the display electronics.
A motor-controller circuit board responsible for all the input power, battery power, external communications and driving the low back-emf, high speed DC brushless motor that runs the air impellor. And lastly, the small air-pressure sensor board that reports back to the main controller. One of the challenges of this design was consistently starting the low back-emf brushless DC motor. High-pressure air is developed using a very low back-EMF brushless DC motor – running at a maximum speed of 12,000rpm, this motor moves air very efficiently. “We were very pleased to develop a coughing machine that would help individuals who suffer from Cystic Fibrosis, ALS, and other muscular diseases, that prevent individuals from coughing on their own,” says Paul Nickelsberg, President and Senior Engineer at Orchid Technologies. “
During the design process we realized the impact this device this would have on people’s lives. Quality of life is important to everyone and our cough-assist design is a miraculous aid for people in need of help.” The development of custom electronics technology solutions for our OEM clients is Orchid’s entire business. High-performance custom medical electronics with rapid design cycles, demanding technical requirements and unforgiving schedules set us apart.
