There is only one alternative to ISRG in the robotic surgery market. It is TRXC (Tranenterix) that has the FDA approved Senhance robot. It will take a long time for any competitors other than ISRG and TRXC because the FDA will only approve surgical robots using the predominately similar to an already approved device criteria. ISRG revenue growth is from selling limited use (10 times?) instruments that then expire. Senhance instruments are "open source" and reusable. ISRG advantage is that they are on hospital supply lists so there is no long sales cycle. TRXC is now an under $5 stock so maybe I am violating ET rules, but market cap is $500 million because of buy out potential.