A medical ventilator (or simply ventilator in context) is a machine designed to provide mechanical ventilation by moving breathable air into and out of the lungs, to deliver breaths to a patient who is physically unable to breathe, or breathing insufficiently. It is a popular and portable ventilation support device, which is suitable for emergency vehicles application or patient transport. Its main work principle is utilizing a continuous gas flow source, then the ventilator provides smooth, reliable ventilatory support via a mask or endotracheal tube. It is widely used in emergency vehicles, and it can be applied to hospitals for emergency ventilation support and for patient transport. Furthermore, the ERS043 transport ventilator has a complete set of ventilation modes and alarms to assure the safety of the patient.