To stop decompression sickness, spacecrafts can use simulated gravity by having large rings or discs that rotate to simulate the gravity of a celestial object (like a small planet or moon). Centripetal force utilised by these rings could solve the health problems related to long term space travel.

>>16699962 (OP)
The difference in g-forces between your head and toes is so significant in these is that it's literally shittier than zero gravity. The only feasible ones have to be tens of meters in diameter. Go ahead and calculate the g-force difference, anon. Literally hs centripetal formula.

With spin gravity your effective acceleration scales linearly with radius/diameter, and like the square of your rate of rotation, and this is further complicated by two things:
1. The presence of Coriolis acceleration in a rotating frame can cause severe nausea, disorientation, and other neurological problems. Since Coriolis acceleration scales like your rate of rotation, this sets a maximum recommended rate of rotation for a spin gravity system.
2. The presence of gradients in your centrifugal acceleration can also cause severe nausea, disorientation, and other neurological problems. Since the gradients in the acceleration scale approximately like your height over the diameter of the station, this sets a minimum recommended size for a spin gravity system.

The Coriolis condition, in particular, is annoying because it means for a particular desired acceleration, your required diameter is going to scale like one-over-the-rate-of-rotation-squared. Wanting to spin twice as slow means building a station four times bigger.

So, for example, let's impose the following limits on our hypothetical spin gravity system (which are completely fucking arbitrary, but we need to start somewhere).
a) Coriolis acceleration for a person walking perpendicular to rotation at 1 m/s cannot exceed 1% G
b) The difference in acceleration between head and feet for a person with a height of 1.8 m cannot exceed 1%

The first condition sets an upper limit on angular rotation of about 0.05 rad/s (just under half an RPM).
The second condition sets a lower limit on the radius of the station to 180 m.
But these upper and lower limits only gets you an effective acceleration of a little under 5% of normal Earth gravity. Even if you bump both limits from 1% to 5%, your max rotation goes up to 0.245 rad/s, and your minimum radius goes down to 36 m, but that only gets you about 22% G (and for all I know, 5% could be way over one or both thresholds).