Whether a comparative analysis of execution methods should focus solely on pre-stimulus psychological pain, and whether Alabama's nitrogen hypoxia protocol constitutes cruel and unusual punishment under the Eighth Amendment

When performing a comparative analysis to determine whether an alternative means of execution would significantly reduce a substantial risk of severe physical and psychological pain, should the comparison focus only on fear and anxiety experienced after the introduction of the fatal stimulus , such as the years, months, weeks, days, or hours during which an inmate knows that their death will happen ? Does the State of Alabama’s nitrogen hypoxia execution protocol, which causes a human to consciously experience symptoms of asphyxiation (air hunger, shortness of breath, aching lungs, elevated heart rate, blood pounding in the ears, the feeling of conscious suffocation or of being trapped deep underwater) for two to seven minutes, constitute cruel and unusual punis hment in violation of the Eighth Amendment where a feasible and readily implemented alternative exists and where that alternative causes a rapid death in which the inmate feels an impact, shock, and numbness, but not pain ?