Respiratory Aid Device
A portable device which uses in-phase vibration to bring relief to patients with respiratory diseases.
In-phase vibration of the chest wall has been shown to have effects on ventilation and dyspnoea. In-phase vibration is applied by a vibratory pad to the inspiratory intercostal muscles during inspiration and to the expiratory intercostal muscles during expiration.
Both inspiratory and expiratory in-phase vibration have been noted to decrease shortness of breath, and increase tidal volume, respiratory flow rates and minute ventilation in normal subjects and patients with COPD, in addition to increasing arterial oxygenation in patients with COPD.
Two studies have noted that in both spinal cord injured (lower cervical - below C4) and COPD patients functional residual capacity decreased with in-phase vibration. There are no known complete stand-alone devices that can provide this functionality.
RAD is a ambulatory device that delivers a mechanical vibration to the wearer’s respiratory muscles in-phase with respiration.
In its current embodiment RAD consists of a system controller, respiration sensor, vibrator controller and a vibrator. Respiration is detected by the respiration sensor.
The sensor data is input to the System Controller executing an algorithm that identifies the inspiration and expiration components of the respiration cycle.
During inspiration the System Controller switches on vibrators attached to the wearer's inspiratory intercostal muscles and switches off vibrators attached to the wearer’s expiratory intercostal muscles.
During expiration the System Controller switches on vibrators attached to the wearer's expiratory intercostal muscles and switches off vibrators attached to the wearer’s inspiratory intercostal muscles.
The frequency of vibration of the vibrators is controlled at 100Hz by a Vibrator Controller executing a control algorithm.
The management of patients with respiratory disorders including asthma cystic fibrosis, COPD and lung cancer. Some specific applications include: during exercise training of patients with respiratory disorders; during the long-term end-stage at home management of patient with chronic respiratory disorders; during exercise training to improve fitness in healthy persons and elite athletes (possible); and the device could be interfaced to a mechanical ventilator to decrease shortness of breath in these patients breathing on the ventilator.
- Dr Bredge McCarren
- John Eisenhuth
- Dr Lyndal Maxwell