lastav and the activity variance act u2014 var measurements are compared to corresponding standing thresholds respectively activity standing threshold and av standing threshold if both variables are above their corresponding standing thresholds the controller 32 continues to step 415 where the controller 32 increments a counter and adds the current digital outputs indicative of x y to an accumulated x y value then at step 420 the controller 32 determines if the counter has reached its threshold value e g 120 counts if the controller 32 has not reached its threshold value the controller 32 returns to step 405 if the controller 32 has reached its threshold value the controller 32 continues to step 425 where the controller 32 determines x c y c by averaging the accumulated x y value over the counter period afterwards in step 435 the controller 32 resets the counter to zero to prepare for another update the controller then returns to step 405 as shown in step 430 if one of these variables is not above the corresponding standing threshold then the counter and the accumulated x y values are reset to 0 and the controller 32 returns to step 405 once the controller 32 has determined what position x c y c corresponds to the patient standing the controller 32 then determines the current body position fig5 a u2013 5b sets forth an exemplary flow chart to determine the current body position of the patient to begin the process the controller 32 sets the current position code current position equal to 1 the current position code is a binary code of 1 or 0 which indicates whether the patient is standing 1 or lying down 0 additionally the controller 32 sets the time the.