Dialyser

Part of speech: noun

Definitions

1. A medical device or laboratory apparatus that separates dissolved substances from a fluid through a semipermeable membrane, as in kidney treatment
2. An apparatus used to remove waste and excess solutes from blood or other liquids by passing them across a selective membrane
3. A machine that filters out impurities from a liquid by diffusion through a membrane, commonly used to clean the blood of patients with kidney failure

Etymology: The word is built from "dialyse" with the agent suffix "-er", so it names the device that performs dialysis. The root of "dialyse" is the Greek "dialusis", meaning a separation or dissolving apart, formed from "dia" (through, apart) and "lysis" (loosening). That Greek sense of coming apart is the key to the term: the process separates dissolved substances from one another by letting small molecules pass through a membrane while larger ones stay behind. The noun's logic is therefore simple. A dialyser is any apparatus that carries out this separation, and in everyday use the word most often refers to the filter component of an artificial kidney machine, where a patient's blood is cleaned of waste products. The name describes what the device does rather than how it looks, which is typical of technical coinages built from an existing verb.

Synonyms: dialyzer