|
It has been reported that a spring arm for the monitor holder in the operating room has come loose on the extension arm.The tension ring / locking ring has slipped out of the groove.The spring arm did not fall off.No injuries to the patient or user were reported.There was also no indication that an ongoing or had to be interrupted.Nevertheless, in case of recurrence, there is a risk of injury due to a possibly falling ceiling construction.
|
|
For the investigation, the reported case was analyzed including the provided photos, email correspondence as well as test and acceptance protocols.The affected spring arm, with its groove for the seat of the affected retaining ring, was inspected on site by a dräger service technician.The retaining ring and the associated shim were shipped to lübeck and examined by a team of engineers from the manufacturer.Detailed information and photos requested were only partially provided for a root cause analysis.The affected spring arm was installed by a contracted outside company on aug.26, 2020.Since then, no further inspection of the arm system has taken place.Apart from the indication that factual installations were carried out on site, no further details are discernible in the inspection and acceptance records provided.It can be assumed that the relevant dräger installation instructions were available to the company at the time of installation.The complainant confirmed that during the on-site troubleshooting, the exact retaining ring that had previously slipped out of the groove in the spring arm pin was repositioned and mounted.The reason given for this procedure was that it would not have been possible to replace the old circlip directly with a new one due to the cable package from storz that had been pulled into the spring arm.The technical support of the storz company was required for the replacement of the spring arm and thus also the use of an unused retaining ring, since the retracted cables have pressed-on plugs which cannot be remounted on the dräger side and generally also cannot be measured.Consequently, the retaining ring that had slipped out of the spigot groove was remounted as a direct and transitional troubleshooting measure.Based on the description and examination results, it can be confirmed that the affected circlip and the associated shim showed significant plastic deformation.This excessive deformation of the retaining ring beyond the elastic range allows the assumption that the ring was already overstretched during the last or initial installation and thus mechanically pre-damaged.The deformation may have been additionally increased by active forces at the time the ring was released from the groove, i.E.When the spring arm was lowered with the system components attached.It can be assumed that the retaining ring used during initial installation was not correctly positioned in the intended mortise and that this encouraged the ring to come out of the mortise.The detachment of the circlip cannot be technically assessed on the spring arm pivot groove itself, as no corresponding photographic or complaint material is available.Weight information on the connected end devices (display support system, displays, possibly other components) is also not known and therefore cannot be evaluated with regard to a possible system overload.Based on all available information and investigation results, it can be assumed that the visible gap formation between the central axis cantilever and the spring arm is due to the retaining ring slipping out of its seat in the spring arm journal at the upper outlet.No design or manufacturing defect could be identified.To avoid such assembly or consequential errors, specific warnings are given in the associated assembly instructions and relevant inspection instructions are included in the operating instructions.The central axle and spring arm manufacturer responsible for the design also assumes that this case involves an assembly error.The affected spring arm including retaining ring and shim must always be replaced with a new retaining ring in compliance with relevant assembly and safety instructions.The necessary support from storz has already been organized.The retaining rings of other spring arm installations were checked on site by colleagues from dräger montage to ensure that they were correctly seated before being handed over to the customer.No comparable events were found in the period under review.The number of similar cases due to the same cause is within the expected range of the respective risk assessment and is therefore accepted.
|
|
It has been reported that a spring arm for the monitor holder in the operating room has come loose on the extension arm.The tension ring / locking ring has slipped out of the groove.The spring arm did not fall off.No injuries to the patient or user were reported.There was also no indication that an ongoing or had to be interrupted.Nevertheless, in case of recurrence, there is a risk of injury due to a possibly falling ceiling construction.
|
