CHEST M.I. INC. was founded in Tokyo in 1965 as Sanwa Seiki Corp., which developed a water-sealed spirometer. The company was re-named CHEST M.I. (Medical Instruments) INC to clarify its specialty in 1974 and began to export into international market. In 1971, they developed the Japan’s first computerized Spirometer, DISCOM. In 1976, the comprehensive pulmonary function testing system, CHESTAC was released.

CHEST have been successively developing new products, such as ASTOGRAPH, airway hyper reactivity test using Forced Oscillation in 1978 (the first of its kind), RHINOGRAPH, a computerized nasal resistance meter in 1980. In 1982, innovative portable, calibration-free spirometer, HI-498 was developed. This product enjoyed big success in Europe and the US, and built-up the company reputation in global market. APNOMONITOR, sleep apnea monitor at home was developed in 1982, PEAKMAN, the handheld electronic Peakflow meter in 1993 (the first of its kind), HOTMATE, 24hr respiratory condition monitor (the first of its kind) in 1998, APNOMONITOR NEURO, Polysomnograph in 2002. More recently, they have succeeded in developing MostGraph, the colored 3D analyzer of respiratory resistance & reactance in COPD and Asthma (the first of its kind). This new method without patient cooperation is expected to improve the diagnosis of respiratory disease.