Preventive Maintenance


Preventive Maintenance (PM) is an ingrained term. PMs have been around for so very long in our industry no one stops to consider them or how they are developed or what they really mean within the industry. The PM has to be done, so there is a schedule to ensure they are performed when they are required per the manufacturer. There is a procedure that the manufacturer has created that is followed and the work is recorded. This allows everyone a sense of security and it protects the hospital or imaging center in case of an audit by licensing, insurance or legal parties. But what is a PM really?

The PM is maintenance that is designed to prevent premature failure and ensure safety. There is no argument that PMs have value. From a purely legal point of view they provide a valid service in protecting from unwarranted litigation. The question is, “Are preventive maintenance procedures really designed to prevent premature failure and ensure safety?”

Preventing premature failure is questionable. There are a number of checks and tests on various machines made by all of the major manufacturers that seem to put more wear on the equipment without any measurable benefit of preventing an early failure. These typically come from one of two origins. A manufacturer builds a CT. They start their PM procedures with all of the basic tests that they have done on all of the CT models they have ever built. There is no consideration from the ground up if the new model needs a specific test. This may be that there simply isn’t enough performance data to result in a true indication of what the highest failure points on the system will be. This leads to the mindset of doing it the way it has always been done being the safe way to go. The people that might have to review the procedure are used to seeing that test on a CT and will ask why it is not there. In a legal contest a lawyer may portray that test as an industry standard, or point out that it has existed on previous models and attempt to make points in a court room. Even if the test isn’t warranted, because of these reasons it may be required.

An example of such a test might be a balance test on a CT unit. If the balance is monitored real time on the unit as a constant, a balance test or a balance calibration being required is simply stress on the CT without any real in performance or safety. Checking the logs and verifying proper balance can serve the same purpose. If the logs report a need for calibration, then the stress of a calibration would be warranted.

Typically, the answer to the safety question is, “yes.” The safeguards, collision sensors and movement limit tests are part of preventive maintenance. However, this can get out of control. In the last 10 years a nuclear medicine camera had a head fall off and crush a patient. Unfortunately, the patient did not survive. What followed was controlled by politics and media spin instead of science and logic. The manufacturer handled it the only way they could. A massive recall and turning a semi-annual 6-8 hour PM into a semi-annual 12-16 hour PM. They now require that all of the bolts that support the detector heads be checked for proper torque.

The reality of the situation was that if proper monthly checks of the center of rotation had been done, there would have been a continual drift. This should have alerted the team that there was a problem in advance. The visual inspections that were to be done semi-annually would have produced the same results. As a result of people that do not understand that there was an individual or group that did not ensure that proper PMs were completed, and that individual or group not being held responsible the manufacturer had to do something. The result is that the manufacturer had to incur a huge expense over the incident, including marketing damage to the brand, and a PM that does not increase safety and increases the cost to maintain the equipment.

What considerations should manufacturers make when creating PMs? If you have ideas of what should and should not be in the PMs, use the feedback mechanisms with the manufacturer. That will have limited impact, but it is still a good place to start. More importantly, become part of your local HTM association. Be active and participate and create a voice that can be heard by the industry. Remember, the laws that are being put into place are done so by elected officials that do not understand medical imaging or medical imaging service. Currently, they rely on the manufacturer for information. To change that, people in the industry will have to participate in creating a group of professionals who can help lawmakers understand the realities of the industry.


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