Osmium is used to produce very hard alloys for fountain pen tips, instrument pivots, and needles: Osmium alloy (1926), and electrical contacts: Alloy Of Platinum And Osmium (1913).
It is also used in the chemical industry as a catalyst:
Osmium filaments have been used in incandescent lamps: Improvements in Electrical Incandescence Lamps with Osmium Filaments (1900).
Osmium compounds have been claimed as a treatment for cancer: Compositions And Methods Comprising Osmium For The Treatment Of Cancers (2019).
References:
All patent information has been obtained from Espacenet (European Patent Office).