IBOT PMD

Description of Event or Problem

USER STATED SHE WAS IN STANDARD MODE LEANING HER ELBOW ON THE ARMREST. THE DEVICE WAS STATIONARY ON LEVEL GROUND. THE USER HEARD A CLICK AS OF THE BRAKES RELEASING, AND THE IBOT MOVED AS IF TO TRANSITION MODES (INTO 4-WHEEL OR BALANCE MODE) AND THEN FELL OVER BACKWARDS. USER REPORTED THAT SHE DID NOT INTENTIONALLY COMMAND A MODE TRANSITION. USER WAS NOT WEARING THE POSITIONING BELT. SHE LANDED ON HER BACK, WITH HER HEAD ON THE HEADREST, AND SLID OUT OF THE SEAT. SHE DID NOT SUSTAIN ANY INJURIES.

Additional Manufacturer Narrative

THE USER STATES THAT SHE DID NOT INTENTIONALLY COMMAND MODE TRANSITION, BUT NEVERTHELESS, THE DATA SHOWS THE COMMANDS WERE RECEIVED. THE USER CONTROLLER WAS RETURNED FOR EVALUATION, AND NO ISSUES WERE IDENTIFIED WITH THE USER CONTROLLER. WHEREAS THE USER STATED SHE WAS LEANING HER ELBOW ON THE ARMREST, IT IS POSSIBLE SHE ACCIDENTALLY PRESSED THE MODE TRANSITION SHORTCUT AND SEAT ADJUSTMENT SHORTCUT. AS TO WHY THE DEVICE FELL, INVESTIGATION FOUND A SOFTWARE ISSUE IN THE RECENTLY-RELEASED SOFTWARE VERSION RUNNING ON THIS DEVICE. IF A SEAT ADJUSTMENT IS COMMANDED DURING A 24 MILLISECOND WINDOW OF A SELF-TEST WHICH OCCURS APPROXIMATELY 1 SECOND AFTER TRANSITION TO BALANCE MODE OR AFTER A SEAT ADJUSTMENT IN BALANCE MODE, TWO SELF-TESTS WILL INTERFERE WITH EACH OTHER, LEADING TO A TIP-OVER.