The Invivo Research model 4500 is a compact Sp02 monitor with built in printer. It is a very reliable unit that is battery powered with approximately 4 hours of battery use. The purpose and function of the pulse oximeter is to continuously and noninvasively measure functional arterial oxygen saturation of arterial hemoglobin (SpO2) and pulse rate (measured by an SpO2 sensor). The monitor is intended for use on adult, pediatric, and neonatal patients in all hospital areas, hospital-type facilities, and home environments. It may be used during intra-hospital transport when powered by its internal battery.