A chest compression apparatus for use by patients with cystic fibrosis, the preferred apparatus including an air flow generator component, a pulse frequency control component having a fan blade valve for producing a sinusoidal wave form, an optional pressure control component, and a patient vest. The apparatus can be used to apply sharp compression pulses to the entire thorax via the inflatable vest worn by the patient. The optional modular nature of the present apparatus provides particular benefits in the manufacture and use of the present apparatus. The modular nature, in essence, provides even greater portability since one or more modules can be individually replaced or repaired as needed, thereby lessening the overall cost and inconvenience to the patient.