1.3.1 Inspection and preventive maintenance
As a BMET, one of your most important jobs will be inspecting and maintaining medical devices. Throughout this course, you will gain knowledge and insights on how to properly do this.
Inspection and preventive maintenance (IPM) includes all scheduled activities that ensure equipment functionality and prevent breakdowns or failures. Performance and safety inspections are straightforward procedures that verify the proper functionality and safe use of a device. Preventive maintenance (PM) refers to scheduled activities performed to extend the life of a device and prevent failure (i.e. by calibration, part replacement, lubrication, cleaning, etc). Inspection can be conducted as a stand-alone activity and in conjunction with PM to ensure functionality; this is important as PM can be fairly invasive in that components are removed, cleaned or replaced.
Instruments when used in an industrial setting are subjected to wear and tear; important resources that drive the instrument can deplete, parts of the instrument on the account of a previous use can get damaged or the calibration of the instrument may be disturbed and may need a recalibration. When the instrument is left unchecked for a longer period of time there is a high chance that it may stop functioning during use or before use. In a hospital setting, the medical instruments that are used have a direct or an indirect impact on the life of the patient who is always on the receiving end of the use of these instruments. And hence the risk that the medical device stops functioning during or before a crucial procedure is unacceptable as it may be detrimental to the life of the patient. And hence safety and functional inspections should be scheduled weekly.
Consider a scenario where a patient in an ICU ward is placed on a ventilator. The ventilator has been used on various patients before and has not been through a thorough maintenance routine. As a result of this, the ventilator’s oxygen filters have not been cleaned and can lead to contamination of the machine which in turn poses a threat to the life of the patient as he has now a probability of contracting ventilator-associated infections like Ventilator-associated-pneumonia.
Here is another example: A defibrillator is a device that generates an electric pulse that kick starts the cardiac muscles of the heart. It is used to resuscitate a non-beating heart or to cure myocardial infarction (irregular beating of the heart) and if not attended to, the patient can die within minutes. Time is key here and the physician/nurse needs to act swiftly and in time to save the life of the patient. The defibrillator needs to be checked daily to make sure that it is generating the right amount of electricity and for the right amount of time. Any changes in these parameters can be fatal to the patient. Imagine if the defibrillator was not maintained. What would happen if the device generates a wrong electrical pulse in the body of the patient? Who is to blame for such ‘accidents’?
It is essential for any healthcare facility, regardless of its size, to implement a maintenance program for medical equipment. The complexity of the program depends on the size and type of facility, its location, and the resources required. However, the principles of a good maintenance program will be the same if it is in an urban area in a high-income country or a rural setting in a low- to middle-income country.
Inventory:
Every hospital should have a preventive maintenance plan. It starts with creating an itinerary of all the instruments available in all the different wards of the hospital. These instruments based on their importance (importance can be attributed based on the risk that the device imposes on the life of the patient if it malfunctions) should be either visited daily/ biweekly/ weekly or monthly. There should be a set protocol for all the things that are needed to be checked. The protocol should involve visual inspections, functional inspections, and cleaning. This will be discussed for every device in the modules that will be covered in the course. These tests and inspections are divided into a daily, weekly, and monthly checklist. As a Biomedical Engineer, you may not have to perform the inspections and the tests mentioned in the daily or the weekly checklists yourself. This is the responsibility of the clinical users and operators. However, as a Biomedical engineer, you need to be aware of these tasks and need to instruct the end-users on how to perform these tasks. And hence, the clinical engineering department and the daily users are also responsible for developing and maintaining the inventory. They are responsible for routinely checking that all the equipment being tracked within a healthcare facility is in the inventory and that all the equipment listed in the inventory can be located. The team may find it convenient to perform an inventory while carrying out routine inspections or PM activities. Furthermore, when new equipment arrives it should be inspected and then added to the inventory.
Maintenance Methodology:
A maintenance program can be implemented in any number of ways so it is important to consider the variety of methodologies that are available. For example, it is possible for a healthcare organization to establish service contracts with device manufacturers, independent service organizations (ISOs), or a combination of both. One of the most important management activities is to decide which services should be provided by which combination of internal and external service providers, based on the capacity of the facility and its staff. The typical approach is to establish some level of management and technical capability within the health-care organization. Where as outside service providers are necessary for the maintenance of complex equipment.
Resources:
Resources needed for maintenance are difficult to project. This requires a maintenance history, calculations of the staff requirement, and knowledge of when a piece of equipment might fail. Maintenance also requires appropriate staff skills, education, and experience. Outside vendors are necessary for the maintenance of complex equipment.
A tool that can be used to measure the effectiveness of the maintenance program is the PM yield. PM yield is the percent of scheduled Inspection and Preventive Maintenace procedures performed where problems were found that affected equipment operation or safety (note: cosmetic problems which do not affect function or safety are not included). This indicator measures the general reliability of the medical equipment at the facility. When individual models of equipment are analyzed it can be useful to compare the reliability of one model against another. Furthermore, it is a measure of the effectiveness of the maintenance programme; if equipment is being well maintained the percentage will be low. Alternatively, if problems are discovered upon inspection that should have been detected by the user, the percentage will be higher.
Given below is an inventory of the equipment in a hospital. Each device is assigned a priority level based on the physical risk associated with the device’s clinical function and hence the importance of the equipment’s function, the maintenance requirement (how easily the equipment wears out or goes out of order), and the incident history of the device. Based on the priority of the device the inspection and preventive maintenance frequency can be scheduled.
Source: World Health Organization. (2011). Medical equipment maintenance programme overview. World Health Organization. https://apps.who.int/iris/handle/10665/44587