Everyday, in hospitals around the world, the electrical activity of humans and animals is measured by countless doctors and veterinarians through the use of electrodes. In some instances, an ECG of the heart is taken to monitor or measure heart abnormalities. Other patients have brainwaves monitored or measured through an EEG. Still other patients require stress tests. Additionally, defibrillators apply electricity to patients through electrodes to stimulate the patient's heart. Through all these procedures and tests, the interface between the patient and the electrode, the electrode-body interface, controls the quality of the signal transferred through the interface. High impedance, i.e. high resistance to the flow of electricity at the electrode-body interface may result in poor signal transmission.
The quality of the electrical signal transferred through the electrode-body interface affects each one of the above mentioned procedures. For an ECG measurement, whether the measurement is simply to monitor the patient's heart cycle or to trigger or gate a device, such as a gamma camera, to record an image of the heart, noise in the signal can negatively affect the results. Noise in the signal can cause improper triggering of the gamma camera and require multiple tests. Additionally, poor electrical signal transfer through the electrode-body interface can cause burning of the skin during defibrillation.
Currently, medical staff attempt to reduce the impedance at the electrode-body interface by eliminating all interfering substances from the skin surface. Medical staff, including nurses and technicians, scrub and cleanse the skin's surface to remove excess debris, oil, hair and any other particles that could raise the impedance at the electrode-body interface. However, without measuring the impedance at the electrode-body interface, the medical staff have no concrete indicator of the impedance of the interface.
Most medical staff use hand-held impedance measurement devices that can measure the impedance at the electrode-body interface. However, these devices are clumsy and time consuming. Each electrode has to be measured individually and each medical staff member has to carry an electrode impedance measuring device.
An early warning system is needed to alert medical technicians that the patient preparation is not finished, and that preparation needs to be continued until an acceptable electrode-body impedance is reached. Therefore, a need exists to automate and facilitate the process of measuring the impedance at the electrode-body interface and provide an early warning system of improper electrical impedance.