The Digital Breathing Machine has been developed to provide an accurate method of reproducing human respiration. A standard breathing machine uses a simple motor driven cam to drive a piston, and is therefore limited to producing a sine wave breathing pattern. This machine uses an electric actuator to directly control the precise position of the piston, enabling any breathing waveform to be reproduced. Human breathing can be recorded using an optional measurement system, and then the machine can reproduce this accurately and repeatably in the laboratory. The machine has been designed to be capable of exceeding the breathing performance of even the fittest human.

The machine has been recently re-designed to use a high quality PTFE/rubber seal around the piston edge, enabling the direct use of the machine as part of the pressure circuit for leak tests etc. The piston seal is capable of seals pressures in excess of 50 bar, though at these elevated pressures the piston needs pressure balancing to reduce the load on the actuator for greater accuracy of reproduction. Contact us for more information on the use and configuration of the machine.

The crux of the system is not the hardware itself, but the software that drives it. The system uses the LabVIEW data acquisition and control software from National Instruments. The control PC is fitted with a low cost data acquisition card and this interfaces with the Breathing Machine, passing data and control signals to and fro as required. A new version of the machine is now available which uses a USB interface unit built into the Breathing Machine, merely requiring a spare USB port on the controlling PC.

Custom software is supplied to drive the Digital Breathing Machine. This is able to reproduce any breathing waveform the human lung can perform. Software is supplied to create waveform files as simple sinewaves or complex described waveforms, or even live subject tests (this needs a suitable flow measurement device). Once a waveform file is created it is stored in the computer to be called up and reproduced as required.

The system is capable of recording and reproducing real life human breathing patterns, when used in conjunction with suitable breathing recording equipment (which can be supplied). Up to one hours subjective flow measurement can be recorded and then reproduced as required. Again, these files are stored on the computer for reproduction as needed.

Software can also be supplied to utilise the other data acquisition functions of the LabVIEW hardware and software, adding continuous monitoring of other data devices such as pressure transducers, flow sensors etc. along with driving the Breathing Machine itself.