A spirometer market is an instrument used to measure the air capacity of the lungs. It measures the volume of air expired by the lungs and entering the apparatus. Spirometer is used to monitor various respiratory diseases such as asthma, emphysema, and bronchitis, among others. Moreover, an incentive spirometer can be used after the surgery, in order to keep the respiratory system healthy. It is used by patients recovering from cardiac surgeries and other related illnesses.