Detection of biological potential in ECG Electrode application

ECG, EMG and EEG measurement instrument through living tissue on the surface of the potential to measure the heart, muscles and brain.

The biological potential measurement, clinicians need to face the challenges in practice. This article will explore the related solutions.

ECG (ECG), electromyography (EMG) and for Electroencephalograph (EEG), respectively, by measuring the electric potential of the surface of the living donor organizations to measure the heart, muscles and brain.

By measuring the flow of ions flow in the body can detect nerve stimulation and muscle contraction, this measurement using bio-potential electrode can be completed.

The biological potential measurement, clinicians need to face the challenges in practice.

Because of the time, an often missing steps is well prepared for patients with skin, so that the electrode through improved access to patients, doctors in acquisition signals will experience problems. Different races, different age levels of patient impedance. In the ECG in the widespread use of the gold electrode, than EMG instrument and EEG instrument usually silver/silver chloride electrode produced higher impedance. Interference signals such as ablation, electrical cauterization, cardiac defibrillator, in vivo in vitro pacing, pacing, pacemaker H field telemetry, as well as various other signals, will have an impact on measurement accuracy.

Solution

The challenges faced by patients and system design.

In the design of the signal conditioning circuits, will ensure high long-term reliable measurement and save labor force and electrode replacement costs. If the skin is bad, front-end amplifiers input bias current allows the electrode polarization. AD8625/AD8626/AD8627 series junction field effect transistor (JFET) input operational amplifier input bias current of less than 1pA. AD8220 and AD8224 junction field effect transistor (JFET) input instrumentation amplifier input bias current below 20pA.

The wide supply voltage range of the amplifier has a wide input voltage range and big gain advantages.

They are able to respond to the emergency room and operating room noise environment. AD8625/AD8626/AD8627 Series IC with 5V ~ 26V single supply. AD8220 and adopt ± AD8224 18V dual supply, or you can use 5V single supply, both devices are available with maximum dynamic range of rail-to-rail output. AD8220 and AD8224 internal each amplifier quiescent current is A 750 μ, is ideal for battery-powered devices. In addition, the AD8224 can also be configured as single-channel, difference output instrumentation amplifier with high resistance to noise-induced.