The accuracy of medical monitoring equipment must be discussed for a specific parameter, range, patient category and operating condition. A claim of absolute accuracy without these conditions is not meaningful.

Pulse oximetry uses light to estimate arterial oxygen saturation. The FDA states that SpO2 readings have a range of uncertainty and that accuracy generally decreases as true oxygenation falls. It also identifies low perfusion, movement, cold skin, ambient light, nail polish and skin pigmentation as possible influences.

Non-invasive blood pressure is also an estimate rather than a direct intravascular measurement. Automatic modules commonly use oscillometry. A cuff that is too large or too small, incorrect placement, an unsuitable arm position, talking or movement can affect the result.

ECG signal quality depends on skin preparation, electrode placement, electrode condition, lead wires and the electromagnetic environment. Temperature measurement must also use the correct probe type and measurement site. The performance of a monitoring system therefore depends on the main unit, parameter module, algorithm, sensor, accessories and operating method.

A product evaluation should cover at least five areas: the declared range and accuracy, the intended patient categories, the validation method and conditions, the approved accessory list, and the limitations and warnings in the instructions for use. If the product is intended for a specific market, the applicable regulatory and standards requirements must also be considered.

OEM and ODM projects need particular care. A change to the sensor, parameter board, software version or critical material may affect performance and risk controls. A matching connector does not prove compatibility. JONSEN's technical information emphasizes early confirmation of parameter modules, LCD, main board, GUI and technical requirements. Moving compatibility checks and validation to the beginning of the project can reduce rework and registration risk.