Section: New Results

Respiratory detection and monitoring

Participants : Xinyue Lu, Christine Azevedo Coste, David Guiraud, David Andreu, Serge Renaux [Neuroresp] , Thomas Similowski [Groupe Hospitalier Pitié-Salpêtrière] .

This work is conducted within a CIFRE PhD thesis. The general subject is the respiration induced by implanted stimulation for the tetraplegic and syndrome of Ondine. In France, every year, there is approximately 90 new spinal cord injuries who have a ventilatory dependence due to a high cervical involvement. The prevalence of syndrome of Ondine (central sleep apnea) would be 25.5 per million inhabitants. Because of many disadvantages of mechanical ventilation, the technique of implanted electrical stimulation to restore the respiratory function of the patients can be proposed. But existing systems are based on open-loop controllers, i.e. the phrenic nerve is stimulated with the same intensity, at the same frequency for the whole time, even when the patients can breathe spontaneously. The principle aim of the work is to develop a respiratory detection/monitoring module in this context.

We have developped a first solution bases on a microphone. The signal is processed in order to determine the spectral power between 400Hz and 600Hz (the band of respiratory sounds) and a threshold detection applied to detect respiration.

Preliminary recordings on healthy individuals have been perfomed. Advance signal processing techniques are now under study.