1980s, DLCO, Helium Dilution FRC, Spirometer Collins DS II, 1986 June 23, 2014 Richard Johnston Leave a comment The DS-II performed spirometry, helium dilution lung volumes and single-breath DLCOs. Photo is from a sales brochure courtesy of James Sullivan, BA, RPFT, Supervisor, Pulmonary Laboratories, Memorial Sloan Kettering Cancer Center