Brown's device is a device for the study and diagnosis of cardiovascular diseases. This device is one of the most modern methods in the diagnosis of coronary heart disease, which leads to the widespread use of instrumental examination of such pathologies as various forms of angina pectoris, arterial hypertension, and cardiac arrhythmias. This method was first introduced in the 70s of the last century. It is highly accurate and is the gold standard for instrumental diagnostics for diseases of the cardiovascular system (in particular, coronary artery disease). Thus, research indicates the need to improve the structure of the service and technology of cardiac diagnostics.