Home telemonitoring is of great interest in respiratory medicine where large numbers of people have long term conditions. We developed a telemedicine instrument for home monitoring of patients with disturbed respiratory muscles. The instrument measures the maximum inspiratory pressure (Pimax), the inspiratory time constant (τ(i)) and connects to the Internet through TCP/IP protocol. The instrument was evaluated by means of a comparative analysis in 18 normal individuals and 15 COPD patients. In close agreement with the pathophysiology, a reduction in Pimax (p < 0.0001) and an increase in τ(i) (p < 0.001) was observed in COPD patients. We concluded that the developed system could be a useful tool for the evaluation of inspiratory muscle and for the implementation of telemedicine services, contributing to reduce the costs of the assistance offered to patients with respiratory diseases.