Medical Device Equipment Calibration is a procedure for detecting and fixing the uncertainties in measurements and bringing them to an acceptable level.
The accuracy of the device has a great deal of importance, as it can seriously affect the diagnostic procedure and endanger patients’ life.
The deviation in output is not necessarily the fault of the device itself, nor can it represent the manufacturer’s incompetence. Most commonly, it results from continuous device usage, which over time affects its internal components, resulting in a deviation from the device standard measurement output.
This article discusses:
- What is Medical Device Test Equipment Calibration?
- Equipment Calibration Related Regulations and Standards
- Why is Medical Device Test Equipment Calibration Important?
- Medical Equipment Calibration Requirements
What is Medical Device Test Equipment Calibration?
There is a difference between medical device test equipment calibration and maintenance activities. Maintenance removes fault in a device, whereas calibration helps to detect the defective instrument that has failed to output values according to the manufacturer’s standard baseline readings.
The calibration activity varies from instrument to instrument. The manufacturer, in most cases, provides a built-in system for performing calibration processes. The manufacturer also recommends calibration frequency, although the user itself can devise its frequency, depending on the instrument application and frequency of use.
Every device has its tolerance limit, as defined by the manufacturer.
If the testing device’s calibration results fall within the tolerance limit, the device can be used further. On the other hand, if the calibration fails the device cannot be used for any process.
Corrective actions are required for devices that fail the calibration.
Such actions can either be performed in-house or the device can be sent to device specialists. Upon successful corrective actions, the device is again calibrated for verification. If results are satisfactory, the device is allowed to be used again. However, if the defect cannot be fixed, the instrument is permanently damaged and cannot be used further.
The calibration cycle is followed by complete documentation.
Common documentation includes:
- Calibration Plan, divided into monthly, quarterly, and yearly basis
- Calibration steps or a Standard Operating Procedure (SOP)
- Calibration Results Sheet indicating the actual results and tolerance limits
Calibration status is also indicated on the device, showing the calibration status, date of calibration, and next due date for calibration.
For example, MRI scanners are regularly calibrated for different sections, including the Imaging Gradients. It allows to keep the imaging output according to standard measurements and helps to accurately detect any changes in tissue structure up to the microscopic level.
Equipment Calibration Related Regulations and Standards
ISO 13485:2016
ISO 13485 is a standard for medical device manufacturers developed by the International Organization for Standardization (ISO). It was reviewed and updated in the year 2016. The number 2016 comes with its terminology.
ISO 13485:2016 is the set of requirements for a Quality Management System (QMS) in the medical device industry.
This standard covers all life cycle stages of the medical device, including manufacturing, storage, distribution, installation, and servicing.
Why is Medical Device Test Equipment Calibration Important?
Medical devices can drift away from the measurements due to their internal components. This phenomenon is common among all manufacturers, even with the most advanced ones. Over time, the internal components – both mechanical and electronics wear and tear. As a result, their performance starts to decrease and results in erratic readings. These erratic readings can directly affect the patient life, such as in the case of ultrasound units.
Secondly, as mentioned above, regulatory bodies such as the FDA in the US have made it mandatory for the manufacturers to perform routine calibration and maintain calibration records. Otherwise, the manufacturer is not granted accreditation and is not allowed to start or continue its operations.
The calibration process is necessary to detect these erratic readings and comply with the regional regulatory bodies. The calibration must be regularly performed, and documentation maintained for presenting during a routine inspection.
Medical Equipment Calibration Requirements
The calibration is critical in the medical device industry and must be performed according to regulatory requirements.
Considering its importance and significance, manufacturers prefer to dedicate separate resources for calibration activity such as:
- Establishing a department
- Hiring skilled personnel
- Implementing an Equipment Calibration Management Software
Procedures and Instructions
It is the manufacturer’s responsibility to develop procedures for regular calibration of each device. The procedure should contain tolerance limits that help in qualifying instruments (fail or pass). In case the device calibration fails, the procedures should guide how to meet the acceptable limit.
Secondly, procedures should document what to do if the device completely fails the calibration.
For example, if a department replaces a device due to fault, it cannot use the new device without calibration and verification from relevant departments such as the Quality Assurance Department. In this scenario, the procedure for a new device calibration is required and should be developed by the device user department. The procedure should also contain steps to replace and update the relevant documents.
Regulatory Standards
This includes the applicable standards for performing routine equipment calibration. The calibration standards should be traceable to national and international standards such as the ISO 13485:2016.
In the absence of available standards, the manufacturer shall establish its own, in-house standards.
Documentation and Records
The calibration activities must be documented and calibrations record well-maintained. A proper calibration plan should be in place, indicating each device’s calibration frequency, i.e., weekly, monthly, quarterly, or yearly. All the calibration records should be readily available during an inspection.
The calibration records should contain the following information:
- Equipment identification number
- The date when calibration was performed
- Name of the person performing the calibration
- The due date for the next calibration
In addition to records, the calibration status or tag should be indicated on the individual device, including the calibration date, the next calibration due date, and the name of the person performing the calibration.
Final Thoughts
Calibration is becoming an important tool for the regulatory bodies to gauge medical device manufacturer compliance adherence. It sometimes becomes difficult to track calibration of all devices, for example, due to human negligence error.
In large manufacturing facilities, some devices are left without their documentation, although they have undergone proper calibration procedures. Sometimes due to equipment or area shifts, device identification is not updated.
All the problems mentioned above can be effectively solved by using digital tools like the Sante Istanbul Calibration Management Software. It helps the manufacturer to adhere to regulatory body requirements streamline various calibration processes.