A target feedback device for ventilatory muscle training.

In a previous study, we successfully used a target feedback device, together with an external resistor, to train the ventilatory muscles of patients with chronic obstructive pulmonary disease. In this article, we describe the details of the design and function of the target feedback device. When used in conjunction with an external resistance, the target feedback device provides timing and pressure targets, together with feedback information, on whether these targets are achieved. The target feedback device consists of readily available electronic components and is relatively simple to construct. Adjustment of an external pressure knob permits setting of pressure targets. Adjustment of internal components is possible and allows control of breathing frequency, inspiratory time, and breathing waveform.