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].
A counter generally increments an internal register each time a voltage pulse is detected at the counter input. This internal register is then read periodically to determine how many events have occurred. Typically used to measure frequency or RPM, accumulate pulses from a tipping bucket precipitation (rain) gauge, and similar counting applications.