5 Critical Factors Important To Medical Device Risk Assessment

Medical device manufacturers must deal with numerous government regulatory organisations whose primary responsibility is to enforce factors such as product safety, effectiveness and proper record keeping. When it comes to medical device risk assessment, experience indicates 5 critical factors that relate to both the medical device and its usage.

I. Design and manufacturing

The medical device risk management should determine if the hazards are caused by omission or commission. In this regard, a medical device can present a hazard in the following cases:

• If it is poorly manufactured - For example, failing to design a structural component that resists the expected stress may lead to its fracture. Such a problem may not be easily fixed with good manufacturing practices, such as quality control or quality assurance. On the opposite, it may simply ensure that a product with a bad design is faithfully produced.
• If inadequate attention is paid to the design elements influencing its performance - Inattention to manufacturing quality assurance may accidentally cause a device defect. For example, improper stressing on a product’s part during the manufacturing phase may result in weakening that part, which subsequently, during the product’s application, may end up with a fracture.
• The medical device does something that can cause harm – E.g. health professionals, using the product, may be harmed by an electric shock from a supposedly well-insulated device.
• It fails to provide its intended benefit - For instance, an error in a patient’s diagnosis may lead to incorrect therapy or no therapy at all, causing severe consequences for the patient.

II. Human Factors

Human factors are the medical device design elements and use conditions that influence the way the device and the user interact. This interaction places an extra complexity on the ability to recognise the hazards that might be associated with a specific device. It would be problematic to have a proper risk management approach without considering the human factors as part of the product’s risk assessment.

III. Materials Toxicity and Degradation

An element of a good design of a medical device is the appropriate material selection. In this regard, toxicity is a crucial element in determining how suitable a material is for a specific medical device. However, it can be challenging to determine all the materials used in medical technology given that the product might contain the following:

• Contaminant material
• Catalytic material used in the synthesis
• Residual material to which the product became exposed during its manufacturing process

A way to deal with such a problem is to use a good manufacturing practice, which includes process validation for ensuring that the selected materials are not compromised. Moreover, it is also imperative that manufacturers of medical devices take into consideration the way the device will be used, i.e. whether will be applied to the body or implanted in the body, and the effect its materials will have on the body and the body on them.

IV. Device Users

Experience shows that the way a medical device is used affects its overall safety and effectiveness. Users of medical devices can be healthcare professionals, patients or family members of patients. Furthermore, some users might be more skilled with a specific medical device than others due to, for example, their different level of training or motivation. In this regard, if the user misuses a medical device, severe consequences may follow. Hazards resulting from user error are not unusual, but sometimes their occurrence can vary from non-existent to frequent, depending on the user’s influence. As overall, when performing risk assessment, all said above must be taken into consideration.

V. Interaction with Other Devices

Sometimes, under specific circumstances, many medical devices may be used within close proximity to one another. The manufacturer of the device usually considers such a case at the design stage, but the ingenuity of device users to devise new systems may outstrip the manufacturer’s expectations. What users normally don’t consider, especially when connecting a number of devices, is the electromagnetic interference of one device with another which could be very hazardous to patients. Moreover, users may even attempt to interchange incompatible parts to repair the device, thus causing a risk to the patient.

The user behaviour is unpredictable, and manufacturers of medical devices must consider factors, related to the interaction of devices, during the risk assessment.

Source:

1. Dhillon, B.S. (2000). “Medical device reliability and associated areas”, CRC Press LLC

2. Fries, R. (2006). “Reliable design of medical devices”, 2^nd, CRC Press