Maintaining a fixed distance during coating of drug coated balloon

A system for coating an expandable member of a medical device that is expandable between an inflated configuration and a deflated configuration, the system comprising:

• a support structure to support an expandable member of a medical device;
• an applicator in fluid communication with a fluid source, the applicator having at least one outlet for applying fluid of the fluid source therefrom, the applicator positioned with the at least one outlet proximate a surface of the expandable member in at least a partially inflated configuration supported by the support structure;
• a drive assembly to establish relative movement between the at least one outlet and the surface of the expandable member to apply fluid on the surface of the expandable member along a coating path;
• and
• a guide to maintain a substantially fixed distance between the at least one outlet and the surface of the expandable member during relative movement therebetween, the guide comprising a channel having at least two constraining members contacting generally opposing sides of the expandable member, the at least two constraining members including a leg of the channel disposed on each of the opposing sides of the expandable member.