Probe
1 - A long, tube-shaped instrument, usually with a blunted/rounded tip, inserted into a body cavity to take samples, or to deliver something. E.g. a duodenal probe is swallowed and passed from the stomach to the duodenum to give drugs or nutrients that might be destroyed by the acid environment of the stomach. 2 - The part of an ultrasound scanner that contains the crystals that send out and receive the actual sound waves/echoes. The probe is usually held tightly on to the patients' skin, with only a thin layer of a water-containing gel between the probe and the skin to eliminate air from any gap between skin and probe.
GE Healthcare Glossary