There is no direct equivalent—watts are units of power and joules are units of energy.
1 joule = 1 watt∙second,
so 360 joules would be 360 watts flowing for one second, or 3600 watts flowing for 0.1 second, et cetera.
Applying Ohm's Law to human organs to determine voltage for a given current through human tissue gets complicated quickly.
A capacitor can store and release joules {energy} but watts are a unit of power, so with watts you have to define a time interval to derive/equate energy.
