Find variables occurring between status changes

Hello everyone,
I have attached an example workbook showing records of 2 tests carried out with outcomes of "normal" or "abnormal", and the dates of 2 variables (in reality I have 100s). I need a way of identifying which variables were present between test dates where there is an outcome change from "normal" to "abnormal" or from "abnormal" to "normal".
ie. a way of searching through the test outcomes and finding where 2 consecutive outcomes are not the same; identifying the range between the dates this change occurs; searching through the dates of Variable1,Variable2... to find if any variables are within the time range where the change occurred; outputting the direction/type of change (normal->abnormal or abnormal->normal) into a column next to the variable date

I have absolutely no idea where to start with this or if it is even possible... Any ideas??? Thanks