Developed in the 1980s, non-invasive ventilatory assist machines differed from traditional ventilation machines in that they didn't require tubing to enter the body in order to provide forced air into a person's airway. They were initially manufactured to offer relief to individuals with sleep apnea, a condition in which the airways become blocked or narrowed during sleep, causing a person to stop breathing for periods of 10 seconds or longer. This cessation of breath can happen five to 50 or possibly more times per hour. Non-invasive ventilatory assist machines, known as CPAP (Continuous Positive Airway Pressure) machines, were the first noninvasive ventilation machines to have a constant pressure of forced air that traveled into the airway, thus keeping it open and preventing narrowing or blockage for the duration of each breath.
Bi-Level Positive Airway Pressure (BiPAP) machines are non-invasive machines that provide positive pressure while a person breathes in and lowers the air pressure when a person breathes out. Thus, the BiPAP has preset pressures: EPAP (exhalation pressure) and IPAP (inhalation pressure). The machine may also have a timing feature for breaths per minute (BPM). If the sleeping person doesn't take a breath, the BiPAP machine increases pressure, forcing the sleeping person to take a breath. The air pressure then decreases, allowing the person to work less against the airflow pressure to exhale. Because the sleeper's breathing varies, so does the BiPAP's pressure, allowing the pressure drop to vary according to the needs of the sleeping individual. This ability to vary air pressure allows the sleeper to exert less energy to exhale and sleep deeper.
The BiPAP machine is similar to a CPAP machine in that the machine runs quietly and is small enough to fit on a nightstand or small table. BiPAP machines can come equipped with heated or non-heated humidifiers. The masks offered are either nasal pillow masks or full face masks. Nasal pillow masks are lightweight and offer reduced pressure points and limited facial contact. They are available with or without chin support. Some are very easy to use and can be applied with one hand. Full face masks cover both the nasal cavity and the mouth. Some include foam inserts for added comfort and pressure point elimination. Typically, a sleep study--which helps determine the cause of sleep apnea--and physician's order are needed to receive a BiPAP machine. When you're fitted for your machine, the technician will help you determine which face mask is best for you. Tubing options vary from 1 1/2 feet to 10 feet in length and have smooth insides to help reduce noise and air resistance.