Advanced Cyclotron Systems, Inc. (ACSI) is a company based in Richmond, British Columbia, Canada that supplies and services cyclotrons predominantly used for the production of medical isotopes by hospitals for nuclear medicine. The company was a spin-off of the research program at TRIUMF. The machines are used for the production of isotopes used in Positron emission tomography (PET), Single-photon emission computed tomography (SPECT) or production of technetium-99 for molecular imaging. ACSI controls approximately half the world market for such machines,
Four models of cyclotrons are offered: