a device that requires skill for proper use

a medical instrument that measures the mechanical force of cardiac contractions and the amount of blood passing through the heart during a specified period by measuring the recoil of the body as blood is pumped from the ventricles

a slender tubular instrument used to examine the bronchial tubes

medical instrument that records electric currents associated with contractions of the heart

a medical instrument for separating substances in solution by unequal diffusion through semipermeable membranes

a medical instrument for local heating of bodily tissues for medical purposes