These instruments are divided into domestic and medical, there are many types, monitoring 1-6 parameters. Including the parameters of the blood samples, oximeters will only determine the oxygen saturation of a parameter. Electrocardiographs are generally used in outpatient hospitals with 3-lead, 6-lead and 12-lead.
Domestic three major brands: Baolite, Myriad, Jinkewei; imports of Philips, GE, optoelectronics, etc.