Patent ID: 8233585

Claim:
An X-ray diagnostic device comprising: an X-ray irradiation means; an X-ray image detection means; a first holding means for holding the X-ray irradiation means and the X-ray image detection means to oppose each other; a second holding means for rotatably holding the first holding means about a first axis; a first driving means for rotatably driving the first holding means; a third holding means for rotatably holding the second holding means about a second axis that is orthogonal to the first axis; a second driving means for rotatably driving the second holding means; and a drive control means for controling the driving speed of the first driving means and the second driving means; wherein the drive control means controls the first driving means and the second driving means so that: (A) one of the holding means, either the first holding means or the second holding means, rotates in steady-state with an angular velocity of a·sin(t) and the other holding means rotates with an angular velocity of b·cos(t) so that the X-ray irradiation means and the X-ray detection means move in a precession motion along a circular or an elliptical orbit; and (B) one of the holding means engages in a run time, ΔT 1 from an initial angle φ 1 using an angular velocity f(t) and the other holding means engages in a run time, ΔT 2 from an initial angle φ 2 using an angular velocity g(t) so that, assuming that a steady-state is reached at time t =T, all of the following equations are satisfied with respect to the parameter ΔT: ∫ t = T - Δ ⁢ ⁢ T 1 T ⁢ f ⁡ ( t ) ⁢ ⁢ ⅆ t = ∫ t = T - Δ ⁢ ⁢ T T ⁢ a · sin ⁡ ( t ) ⁢ ⁢ ⅆ t ⁢ ⁢ ∫ t = T - Δ ⁢ ⁢ T 2 T ⁢ g ⁡ ( t ) ⁢ ⅆ t = ∫ t = T - Δ ⁢ ⁢ T T ⁢ b · cos ⁡ ( t ) ⁢ ⅆ t ⁢ ⁢ f ⁡ ( T ) = a · sin ⁡ ( T ) , f ⁡ ( T - Δ ⁢ ⁢ T 1 ) = 0 ⁢ ⁢ g ⁡ ( T ) = b · cos ⁡ ( T ) , g ⁡ ( T - Δ ⁢ ⁢ T 2 ) = 0 ⁢ ⁢  ⅆ ⅆ t ⁢ f ⁡ ( t )  ≤  a  ⁢ ⁢ ( T - Δ ⁢ ⁢ T 1 ≤ t ≤ T ) ⁢ ⁢  ⅆ ⅆ t ⁢ g ⁡ ( t )  ≤  b  ⁢ ⁢ ( T - Δ ⁢ ⁢ T 2 ≤ t ≤ T ) ⁢ ⁢ ϕ 1 = - a · cos ⁡ ( T - Δ ⁢ ⁢ T ) ⁢ ⁢ ϕ 2 = b · sin ⁡ ( T - Δ ⁢ ⁢ T ) , Equation ⁢ ⁢ 1 wherein a and b are maximum angular velocities, t is time and ΔT is the time of rotation from angles φ 1 and φ 2 to reach an angle under a steady-state angular velocity based on a·sin(t) and b·cos(t).