Which of the following describes a common mechanical failure in medical devices?

A common mechanical failure in medical devices refers to issues related to the physical components of the device rather than software or procedural problems. When it is said that "parts not moving as intended" is the correct choice, it highlights how mechanical failures can seriously impact the functionality of medical equipment. For instance, if a critical component like a pump or a valve fails to operate properly, it can lead to inadequate therapy delivery, which is critical in patient care.

This option emphasizes the essential nature of mechanical integrity in medical devices. Devices often rely on moving parts to function optimally, and any failure in this mechanical operation can lead to malfunctioning equipment, which can jeopardize patient safety and successful outcomes.

Other options address different types of failures or issues that may arise. Persistent alarm notifications relate more to alert systems that may be triggered by software or mechanical issues but do not specifically indicate a mechanical failure. Improper sensor calibration pertains to the accuracy of readings and does not directly involve mechanical components. Software updates required imply a need for improved system performance or security but again, it is not a mechanical issue. Thus, the focus on mechanical operations makes the correct answer pertinent to understanding common failures in medical technology.