Risk Management for Medical Devices

Transcription

1 Risk Management for Medical Devices CĂLIN CORCIOVĂ, MARIUS TURNEA, RADU CIORAP Department Biomedical Science Faculty of Medical Bioengineering, Grigore T. Popa University of Medicine and Pharmacy - Iasi M. Kogalniceanu Street, No 9-13, Iasi ROMANIA calin.corciova@bioinginerie.ro, Abstract: - Medical devices developed for human application are used for diagnostic or treatment purposes. They may either be an instrument, an apparatus or a material. Moreover, these devices can be used for daily patient care as well as for medical scientific purposes. Risk management involves the identification, understanding, control, and prevention of failures when the medical devices are connected to the patient and also for the people who use these medical devices. In this paper, we present a multi-criteria decision-making model to prioritize medical devices according to their criticality. Devices with higher criticality scores can be assigned a higher priority in a maintenance management program. A computerized medical management system is described. The results demonstrate that it is a useful tool in tracking device inventory and maintenance history. Also risk classes have been designed for medical devices based on the time of testing, risk must be identified in relation to patient and personal staff. The results of this paper take into consideration the advances in device reliability, reduced preventive maintenance requirements, and internal device surveillance (self test) along with changes in standards. Key-Words: - criticality prioritization, medical devices, models, maintenance requirements, risk, software 1. Introduction The globalization of the medical device market place, combined with the growth of medical device usage, has led to a significant increase of the complex task of making a medical device safe for human use activity among device manufacturers. Risk management has become an important competitive tool to gain access to foreign markets. As clinicians, patients, regulators, and litigators become more sensitive to safety issues related to human factors, the importance of appropriate translation and safety controls will increase [1]. Risk management is necessary to ensure device usability, safety, and regulatory compliance. In some cases, critical human factors and risk management decisions are made that depend on specific language in the user interface or labeling. For instance, hazardous situations can arise based on improper interpretation of date/time information or units of measurement displayed. Risk management involves the identification, understanding, control, and prevention of failures that can result in hazards when people use medical devices. Manufacturers are expected to identify possible hazards associated with the design in both normal and faulty conditions. The risks associated with the hazards, including those resulting from user error, should be calculated in both normal and faulty conditions. If any risk is judged unacceptable, it should be reduced to acceptable levels by appropriate means. An overall risk management process involves the essential steps in Fig 1 [3]. In order to manage risk, hazards must first be identified. By evaluating the potential consequences of hazards and their likelihood, a measure of risk can be estimated. Fig. 1. Risk Management Flow Chart This paper presents a software system, integrating a number of software packages, serving specific management processes, each of them able to work either as a stand alone application, or ISBN:

2 interlinked between each other through properly designed communication tools and facilities. 2. Problem Formulation The risk assessment should be done for each new device type during the incoming inspection when the device is added to the inventory. The device will then have a testing frequency assigned. After this is done, the maintenance history of the device should be monitored in order to evaluate the effectiveness of the maintenance program (Fig.2). Fig. 2 Logical diagram for assessing medical equipment The main objective of this software system is to assist the biomedical engineer or clinical engineer in performing tasks, concerning the assurance of safety and efficiency in use of medical equipment. Requirement analysis resulted in the following features, which the system should include: - Management of data for medical devices, manufactures and suppliers; - purchasing procedures; - Implementation and management of the quality and safety protocols and procedures, including the necessary documentation and data; - Corrective maintenance activities; - Scheduling of all the routine procedures, like acceptance testing, preventive maintenance, quality and safety inspections; - Management and monitoring of the training provided by the manufactures or technical staff include biomedical engineer or clinical engineer; - Monitoring of the quality of the overall performance of the department, using quality and cost indicators; - Report generation predefined or customized by the users. Medical equipment should be evaluated to determine how often testing should be performed. If a device is not tested often enough, it may fail before the next scheduled maintenance or give erroneous results. If a device is tested too frequently, time that could be better spent maintaining other equipment is wasted. The biomedical professional s job is to achieve a balance between the time and effort needed for periodic functional testing and the safe use of medical equipment. In order to maintain an efficient maintenance program, the frequency of inspection must be determined [4]. Effort should be spent on equipment where testing is likely to have an impact on the continued safe operation of the medical device. The software has developed to a risk-based system for determining the maintenance frequency. Intervals are established for equipment inspection based on risk, requirements, logistics, and history. Written criteria are used to identify risks associated with medical equipment per the maintenance strategy. The risks include equipment function, physical risks associated with use, and equipment history as it relates to patient safety. Life support equipment is specifically identified and receives the highest priority for actions. The risk criterion is divided into four categories: clinical function, problem avoidance probability, incident history, and regulatory or manufacturer requirements. Devices are given a score for each of these categories. The scores for each category are added up and a total score is given for each device type. Maintenance strategies are determined based on the total score. A combined score of 12 or more is justification for semiannual testing, a score of 9-11 is justification for annual testing, and a score of 8 or less is justification for less than annual testing, either bi-annual or no scheduled testing, depending on clinical application. The result is a more cost- ISBN:

3 effective test program that will result in improved patient care through less equipment downtime and more dollars for direct patient care activities. 3. Problem solution Understanding what devices are in the facility in order to provide a quality maintenance program is critical. Inventory data is used for a variety of applications including establishing a maintenance schedule, tracking medical device hazards and recalls, and deciding when to replace aging equipment [7]. A computerized medical equipment management system is an useful tool in keeping track of the device inventory and maintenance history. Any medical equipment management software should track basic device information. At a minimum, the device type, manufacturer, model, and serial number should be tracked. This information is essential to the maintenance program. The clinical use of a device should be documented. Equipment used for life support needs to be given a higher priority for maintenance. Additionally, regulations on life support devices may be different. Our software developed in Visual FoxPro respect all these conditions above. The equipment location is used to find the equipment for maintenance. Also, the location is useful to break up the maintenance schedules by department (Fig. 3). The developed program allows user access, service employees involved, depending on the characteristics of each job description and duties (Fig.4). A record should be kept of all maintenance performed on equipment, including scheduled maintenance, repairs, software upgrades, and incident investigations (Fig.5). Dates of service should be included in this history. Fig. 5. Identification data of the medical equipment The software comprises all the information stored in predefined catalogs supported by the system (suppliers, manufactures), as well as data regarding the types of failures that have occurred, or can potentially occur to medical equipment. The Services module, concerns the system management supporting possibilities. It covers basic maintenance and management operations. It includes acquisition, concerning new device purchase, offer estimation and contract management, periodic inspections of medical devices. Fig.3 Access in to the system It also contains information about the hospital itself, its departments, personnel and specialties. Detailed hospital profile is also available, presenting an additional general hospital information, including its identity data, such as address, number of beds, number of personnel, technical staff. Fig. 6. Module record of servicing equipment Fig. 4. User access in the application Clinical function represents how invasive the equipment is to the patient. At the low end of this category is a device that does not make patient contact, for example, an exam light. The high end of ISBN:

4 this category is a device used for life support, such as a ventilator. Problem avoidance probability is based on historical data related to medical equipment repair and maintenance. The low end of this category is maintenance or inspection having no impact on the reliability of the device; the high end is common device failures are predictable and can be avoided by preventive maintenance. This category also has an additional level, specific regulatory or manufacturer s requirements that dictate preventive maintenance or testing. The device incident history is also based on historic data. This category only has two scores, and is answered as yes or no. If a device had a history of being involved in an incident resulting in patient harm, the device would score high. Otherwise, the device would score low. 4. Results and discussions To illustrate risk criteria we discussed the two types of equipment used extensively in healthcare: defibrillator and enteral feeding pump. Defibrillators deliver an electric impulse to the heart through the chest wall in order to restore a normal rhythm in patients experiencing ventricular fibrillation or ventricular tachycardia. The high electrical energy stops the independent action of the individual muscle fibers, so that the natural pacemaker of the heart can take over. A set charge is generated and is delivered through a set of paddles or disposable defibrillation electrodes through the chest wall. The defibrillator s output energy is typically selectable from 0 J to 360 J. Most defibrillators also include an electrocardiograph to monitor the patient s rhythm. Some defibrillators include a pacer function. Electrical impulses are delivered to the heart, causing the heart to contract. This is used for emergency treatment of asystole, severe bradycardia, implantable pacemaker failure, or other conditions requiring emergency cardiac pacing. For this equipment verification procedure that must contain: electrical safety - ground wire resistance, chassis leakage, and lead leakage - and performance inspection that include: measure if the energy output of the defibrillator throughout its range. At a minimum, measure the output at the lowest setting, a mid level setting, and the highest setting. The output should be within 15 % of the set energy level. At 360 J, the energy output should be between 306 J and 414 J. Another test is output energy at maximum setting for 10 charge cycles. On the tenth shock, the energy output should still be within 15 % of the setting. Charge time after 10 charge cycles should not exceed 15 s. Recommended functional test frequency: semiannual (Table 1). Table 1 Sample risk assessment for defibrillator Criteria Risk Score Clinical function No patient contact 1 Device may make contact with patient non-critical 2 Device is used for patient diagnosis or direct monitoring 3 Device is used to deliver direct treatment to the patient 4 Device is used for a life support 5 5 Problem avoidance probability Maintenance would not impact reliability of the device 1 Common device failure modes are unpredictable 2 Common device failure is predictable and can be avoided by preventive maintenance 3 Specific regulatory requirements dictate preventive maintenance or testing 4 4 Incident history No History 1 A significant history of incidents exists 2 2 Manufacturers/regulatory requirements for specific schedules No requirements 1 There are requirements for testing 2 2 TOTAL 13 Times per year tested 2 ISBN:

5 Enteral feeding pumps are used in patients without gastrointestinal complications who are unable or unwilling to consume adequate nutrients. Feeding solutions are delivered to the patient through temporary or surgically implanted feeding tubes. The pumps accurately control the flow of liquid feeding solutions that are administered enterally, through the digestive tract. These pumps will utilize a pump mechanism such as a rotary peristaltic pump, linear peristaltic pump, or a volumetric pump. Most pumps record the dose rate, dose settings, and infused volume in the memory. Audible and visual alarms alert the user to flow changes or malfunctions. The delivered volume should be within 10 % of the set volume. For a set volume of 10 ml, the measured volume should be within 9 ml and 11 ml. The measured occlusion pressure should be within 1 psi of the pump s occlusion pressure. For an occlusion pressure of 20 psi, the measured pressure should be between 19 psi and 21 psi. Recommended functional test frequency: annual (Table 2). Before returning to use, return any settings that were adjusted to their original settings. Ensure the volume of the audible alarms is loud enough to be heard in normal operating conditions. TABLE 2 Sample risk assessment for enteral feeding pump Criteria Risk Score Clinical function No patient contact 1 Device may make contact with patient non-critical 2 Device is used for patient diagnosis or direct monitoring 3 Device is used to deliver direct treatment to the patient 4 4 Device is used for a life support 5 Problem avoidance probability Maintenance would not impact reliability of the device 1 Common device failure modes are unpredictable 2 2 Common device failure is predictable and can be avoided by preventive maintenance 3 Specific regulatory requirements dictate preventive maintenance or testing 4 Incident history No History 1 1 A significant history of incidents exists 2 Manufacturers/regulatory requirements for specific schedules No requirements 1 1 There are requirements for testing 2 TOTAL 8 Times per year tested 1 The advantages of this integrated system are related to flexible management of small databases, avoiding problems with lost and corrupted records, higher system reliability, customized search engines, high record processing speed, system flexibility and real time data presentation and analysis. Furthermore, the implementation of a flexible communication connection between these specific parts carries out the data transmission to the central module, producing daily reports for medical device condition and the necessary maintenance procedures, needed to be accomplished. 4. Conclusion Quality health services involve the correct and efficient resources. A result that can not be neglected is balancing investment and equipment maintenance costs. Organization and proper use equipment carried by a clear policy, supported by technical guidance and practical tools to improve the operation of equipment. Medical will be able to significantly improve the quality of services and service efficiency. Such management practices will contribute to increased efficiency in health sector will result in improved health outcomes and a service as durable. Equipment maintenance analysis to assess the duration of life can be extended or shortened. Such equipment maintenance is crucial for life. If not is met on time and regularly, the device will deteriorate to the point at which will cost more to fix than to replace. If we do not interfere at all ISBN:

6 in the equipment maintenance, it will degrade irreparably. The importance of maintenance activities is to effectively manage the equipment; this task necessitates complex information about the medical device. Thus it is necessary to make an archive of what happened in the past, to tell if the situation improves and you learn from previous situations. Finally, record maintenance activities provide the staff valuable technical information and evidence that they can use when they need argues need help or additional resources. Data base system maintenance helps keep health service records of repairs and other actions. References: [1] T. Cohen, Computerized maintenance management system: How to match your department s needs with commercially available products, Journal of Clinical Engineering, vol. 20, No. 6, 1995, pp [2] S. Panousis, P. Malataras, C. Patelodimou, Z. Kolitsi, N. Pallikarakis, Development of a new clinical engineering management tool & information system (CLEMANTIS), Journal of Clinical Engineering, vol. 22, No. 5, pp [3] Risk management guidance, Medical Equipment Compliance Associates LLC, [4] Introduction to medical equipment inventory management, WHO Medical device technical series, [5] Medical equipment maintenance programme overview, WHO Medical device technical series, [6] P. L. Jones et all, Risk management in the design of medical device software systems, Biomedical Instrumentation & Technology, Jul./Aug., 2002, pp [7] B. J. Wood, Software risk management for medical devices, Medical Device and Diagnostic Industry, Jan., 1999, pp [8] Ganeshkumar Palanichamy, Basic principles of risk management for medical device design, Wipro Technologies, [9] H. Julian, Biocompatibility assessment of medical devices and materials, John Wiley & Sons, [10] Inspection and preventive maintenance system, ECRI Institute, ISBN: