bIoMeDiCaL EnGiNeErInG - PaTiEnT MoNiToR

Patient Monitor or “Multiparameter monitor” or also referred to as “Physiological Monitor” is a clinical use electronic machine designed to display and minimally interpret, a person’s vital signs. Some monitors can warn of pending fatal cardiac conditions before visible signs are noticeable to clinical staff ( PVC , the premature contraction of the heart ventricle).

The parameters (or measurements) usually consist of pulse oximetry (measurement of the saturated percentage of oxygen in the blood referred to as SpO2), ECG (electro-cardiograph of the p-QRS-t wave of the heart w/wo pacemaker), blood pressure (either invasively through an inserted blood pressure-to-transducer assembly or non-invasively with an inflatable blood pressure cuff) ,and temperature (usually skin temperature through an adhesive pad. There are more parameters such as Cardiac output, CO2 measurement (referred to as EtCO2 or end-tidal carbon dioxide), respiration (through ECG channel or via EtCO2, when it is called AWRR or airway respiratory rate), anaesthetic gas measurement, etc.

Patient monitors can be broadly categorized as standalone or multiparameter. Standalone monitors continue to be used in developing countries like India mainly due to cost restraints and also because they are easy to manufacture and maintain. In developed part of the world, multiparameter monitors have supplanted them, in some cases because of statutory requirements (for example the US FDA) and also because if a clinician requires to monitor one channel then other channels are also needed to complement the data and get a fuller picture of the patient’s vital signs (for example: ECG+SpO2+Respiration or SpO2+ NIBP or ECG+SpO2+Resp or ECG+SpO2+Resp+NIBP+Temp+Pressure with our without EtCO2).

Companies are working to integrate the physiological data from the isolated patient monitoring networks into the emerging hospital digital charting systems using HL7. This newer method of charting patient data reduces the likelihood of human documentation error and will eventually reduce overall paper consumption.