US Patent 7811230 Expansion mechanism for minimally invasive lumbar operation

An expansion mechanism for minimally invasive lumbar operation has a support member, a plurality of sliders movably assembled on the support member, at least a couple of outside muscle hook members mounted on adjacent sliders, an inside muscle hook member assembled on the slider, and a nerve hook member assembled on the slider. The expansion mechanism for minimally invasive operation makes small incisions and hurts less tissues. Furthermore, the expansion mechanism protects nerve tissues from repeated stirring. Muscles can be drawn apart without the need of removing ligament, obtaining clear and large operation vision.