Ventilators are typically used by ALS patients having difficulty breathing. There are several kinds of non-invasive ventilators, such as small devices that fit over the nose and mouth. Patients may also opt for a tracheostomy, a surgical procedure in which a tube is placed into the throat.
3. Counters. A counter is a digital sequential logic device that will go through a certain predefined states (for example counting up or down) based on the application of the input pulses. They are utilized in almost all computers and digital electronics systems [1].
It is a measure of the number of digits in the reading of the signal frequency. Most frequency counters are what are termed direct reading counters, and the resolution is determined by the gate time. This is the time for which the counter is counting the number of pulses or transition crossings.