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EKG/ECG electrode

Electrocardiography (EKG, ECG) is a medical test for recording the electrical activity of the heart. Electrocardiograph (EKG) machines are used as a diagnostic tool in medicine, and measure electrical activity in the heart muscle. After each contraction of the heart, an electrical impulse is generated in the sinoatrial node (SA) of the heart. The EKG machine traces the path of the impulse as it spreads though the heart, and produces a graph or trace of the electrical impulses often referred to as an electrocardiogram (ECG). The electrocardiogram (ECG/EKG) is a valuable diagnostic tool used extensively by cardiologists worldwide. ECG signals are commonly detected by an ECG signal detection device that includes a pair of electrodes each incorporated into an adhesive pad designed to be placed on a patient's chest. Leads connect the electrodes to the inputs of a differential input amplifier. The differential amplifier detects the slight ECG signals associated with the contraction of the heart and amplifies the ECG signals so that the ECG signals can be analyzed and/or displayed for analysis by a medical instrument such as a defibrillator. Typically a technician will place sensors on a patient's chest. The sensors are electrodes having an adhesive gel for adhering to the skin of the patient as well as for providing electrical conductivity. The ECG records the electrical activity of the heart detected through small electrodes (leads) placed on the patient's chest, wrists and ankles. The ECG monitors voltage signals appearing between various pairs of the electrodes and performs a vector analysis of the resultant signal pairs to prepare various two-dimensional voltage-time graphs indicative of internal cardiac activity. ECG electrodes employed in clinical use typically require skin preparation to achieve low impedance electrode coupling. Low impedance electrode coupling facilitates minimizing the variation of DC coupled ECG input amplifiers. A basic ECG electrode system generally includes the use of at least two electrodes and corresponding electrical lead wires. These lead wires transfer electrical energy from the electrodes, in position upon a patient, to a monitoring apparatus. The electrodes are typically small, round or square, electrically conductive patches, which can be attached to the patient's skin with an adhesive, or with suction, to make electrical contact with the patient's skin.

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