Electrocardiograph is an instrument used in the detection and diagnosis of heart abnormalities. It measures electrical potentials on the body surface and generates a record of the electrical currents associated with heart muscle activity. It produces an electrocardiogram that shows the electrical activity of the heart over time. Analysis of the various waves and normal vectors of depolarization and repolarization yields important diagnostic information. It is also called cardiograph.

Epilation forcep is small, stout and has blunt ends whose inner surfaces are flat and smooth. It is necessary for epilation of the offending eyelashes as in trichiasis. It is more commonly known as tweezers.

Electrooculography is a method for measuring the resting potential of the retina. The resulting signal is called the electrooculogram. It is used to assess the function of the pigment epithelium. During dark adaptation, the resting potential decreases slightly and reaches a minimum after several minutes. When the light is switched on, a substantial increase of the resting potential occurs, which drops off after a few minutes when the retina adapts to the light. The patient is asked to switch the eye position repeatedly between two points (usually to the left and right of the center). Since these positions are constant, a change in the recorded potential originates from a change in the resting potential.