In any medical malpractice liability action, as defined in Kan. Stat. Ann. §§ 60-3401 and amendments thereto, in which the standard of care given by a practitioner of the healing arts is at issue, no person shall qualify as an expert witness on such issue unless at least 50% of such person’s professional time within the two-year period preceding the incident giving rise to the action is devoted to actual clinical practice in the same profession in which the defendant is licensed.