Band 61, Heft 2 - Special issue: Risk Management in Medical Human-Machine Systems / Guest Editors: Wolfgang Lauer and Klaus Radermacher

The number and complexity of user interfaces in the OR has been considerably increasing during the last years. Moreover, increasing cost and time pressure force surgeons and surgical nurses to perform different tasks in parallel. We analyzed the workflow of 25 neurosurgical procedures with a workflow analysis tool in order to analyze the present situation in the neurosurgical OR and to identify potential use-oriented risks and to develop first proposals for respective countermeasures. Application of the navigation system, the CUSA ultrasonic aspirator, and the PACS-PC was associated with errors and resulting potential risks. A number of different disruptive factors have been identified, the most prominent of those being intraoperative duty phone calls, longer absence of the circulating nurses or slipped off foot switches. Furthermore, the identified problems may lead to risks for patient, and also for staff by use errors, associated with an inappropriate cognitive workload of the surgeon or nurses. Organizational and technical countermeasures are necessary: to enhance communication, team trainings could be helpful, and the setup of a mailbox could reduce the number of intraoperative duty phone calls. Technical deficiencies have to be reduced, e.g. with more user-oriented design of devices, such as foot switches, or standard design for user interfaces. For further risk reduction in the case of use deficiencies, we propose the implementation of device interoperability and the use of a sterile integrated user interface in a networked OR.

Medical devices emit alarms when a problem with the device or with the patient needs to be addressed by healthcare personnel. At present, problems with device alarms are frequently discussed in the literature, the main message being that patient safety is compromised because device alarms are not as effective and safe as they should – and could – be. There is a general consensus that alarm-related hazards result, to a considerable degree, from the interactions of human users with the device. The present paper addresses key aspects of human perception and cognition that may relate to both operating alarming devices and responding to device alarms. Recent publications suggested solutions to alarm-related hazards associated with usage errors based on assumptions on the causal relations between, for example, alarm management and human perception, cognition, and responding. However, although there is face validity in many of these assumptions, future research should provide objective empirical evidence in order to deepen our understanding of the actual causal relationships, and hence improve and expand the possibilities for taking appropriate action.

Studies regarding adverse events with technical devices in the medical context showed, that in most of the cases non-usable interfaces are the cause for use deficiencies and therefore a potential harm for the patient and third parties. This is partially due to the lack of suitable methods for interlinking usability engineering and human-centered risk management. Especially regarding the early identification of human-induced errors and the systematic control of these failures, medical device manufacturers and in particular the developers have to be supported in order to guarantee reliable design and error-tolerant human-machine interfaces (HMI). In this context, we developed the HiFEM methodology and a corresponding software tool (mAIXuse) for model-based human risk analysis. Based on a two-fold approach, HiFEM provides a task-type-sensitive modeling structure with integrated temporal relations in order to represent and analyze the use process in a detailed way. The approach can be used from early developmental stages up to the validation process. Results of a comparative study with the HiFEM method and a classical process-failure mode and effect analysis (FMEA) depict, that the new modeling and analysis technique clearly outperforms the FMEA. Besides, we implemented a new method for systematic human risk control (mAIXcontrol). Accessing information from the method’s knowledge base enables the operator to detect the most suitable countermeasures for a respective risk. Forty-one approved generic countermeasure principles have been indexed as a resulting combination of root causes and failures in a matrix. The methodology has been tested in comparison to a conventional approach as well. Evaluation of the matrix and the reassessment of the risk priority numbers by a blind expert demonstrate a substantial benefit of the new mAIXcontrol method.

Severe bottlenecks in usability and human technology interaction (HTI) of existing surgical workplaces and operating room (OR) equipment can occur today: lack of space, cable as trip hazard, communication problems between sterile and non-sterile staff, and operating errors in the handling of the medical devices. In fact, risks that are caused by poor usability can be critical, and studies show that most are preventable. This issue gets even more challenging in the context of open-OR networks regarding consistent and usable integration of user interfaces (UIs) of independently designed systems in one integrated surgical work system. In this work, a concept of generic UI profiles for the modular integration of a UI has been developed and first prototypes have been implemented. The concept is essentially based on the approach of device profiles developed in the context of the Bundesministerium für Bildung und Forschung project OR.NET (www.ornet.org). We developed generic UI profiles to map the different interfaces of the medical devices on an integrated surgical UI. The integrated UI design shall be automatically verified according to agreed usability criteria, guidelines, and human error taxonomies.

Introduction: Alarm conditions of the technical equipment in operating rooms represent a prevalent cause for interruptions of surgeons and scrub nurses, resulting in an increase of workload and potential reduction of patient safety. In this work, an alarm concept for an integrated operating room system based on open communication standards is developed and tested. Methods: In a laboratory experiment, the reactions of surgeons were analysed, comparing the displaying of alarms on an integrated workstation and on single devices: disruptive effects of alarm handling on primary task (ratings of perceived distraction, resumption lag, deterioration of speed, accuracy, and prospective memory), efficiency and effectiveness of identification of alarms, as well as perceived workload were included. Results: The identification of the alarm cause is significantly more efficient and effective with the integrated alarm concept. Moreover, a slightly lower deterioration of performance of the primary task due to the interruption of alarm handling was observed. Conclusion: Displaying alarms on an integrated workstation supports alarm handling and consequently reduces disruptive effects on the primary task. The findings show that even small changes can reduce workload in a complex work environment like the operating room, resulting in improved patient safety.

The inadequate use of syringe pumps can jeopardize patient safety, and syringe pump trainings are conducted to manage this risk. A critical step in this risk management process is the learning success of trainees. In the present paper, we compared an e-learning approach with standard classroom training in learning success effectives, trainees’ opinion on the trainings, and investigated the relation between technological affinity and learning success. The results showed that e-learning was as effective as classroom training but nursing students’ confidence in using the pump and satisfaction with the training was decreased for e-learning compared with classroom training. We discuss the results in context of the nursing e-learning literature. Finally, we discuss the literature for risk identification, risk analysis, risk treatment, and risk monitoring and control in the context of syringe pump training and add the lessons learned from the evaluated e-learning program.

A safe application of modern surgical technology and computer-assisted surgery devices is based on an operation by adequately trained surgeons who are familiar with the benefits and limitations of the devices. We analyzed the in-depth interviews with seven Spanish and 10 German surgeons. Together with other studies, this analysis highlights the need for specific training in technological competence for surgeons. One way to train technological competence is to help surgeons understanding the basic principles of medical devices as well as explaining the basic concepts of risk analysis and risk management. Based on this premise, a stage model for risk assessment was developed and adapted for the training of surgeons. This was developed further into a train the trainer (TTT) concept, which was then evaluated for two example cases. During TTT-training, the trainers (expert surgeons) performed a risk analysis for several medical devices. Afterwards, the trainers organized a surgical workshop for surgical trainees (resident surgeons), in which high-fidelity simulators and the original medical devices were used. The results showed that the surgeons performed the risk analysis correctly with the stage model and afterwards were able to successfully apply the results in the workshop context.

Registries are powerful tools to support manufacturers in the fulfilment of their obligations to perform post-market surveillance and post-market clinical follow-up of implantable medical devices. They are also a valuable resource for regulators in support of regulatory action as well as in providing information around the safety of new and innovative technologies. Registries can provide valuable information on the relative performance of both generic types and manufacturer’s individual products and they complement other sources of information about device performance such as post-market clinical studies and adverse incident reporting. This paper describes the experience of the UK medical device regulator – the Medicines and Healthcare Products Regulatory Agency (MHRA) – of working with registries to monitor the safety and performance of medical devices. Based upon this experience, the authors identify a number of attributes for a registry which they consider to be key if the registry is to contribute effectively to the work of regulators on patient safety monitoring and medical device regulation.

Medical devices are manifold and one of the most innovative fields of technology. As technologies advance, former limits cease to exist and complex devices become reality. Medical devices represent a very dynamic field with high economic relevance. The manufacturer of a medical device is obliged to minimize product-related risks as well as to demonstrate compliance with the so-called “essential requirements” regarding safety and performance before placing the device on the market. Any critical incident in relation to the application of a medical device has to be reported to the competent authority for risk assessment, which in Germany is either the Federal Institute for Drugs and Medical Devices (BfArM) or the Paul Ehrlich Institute (PEI) depending on the type of device. In this article, the German regulatory framework for medical devices and the resulting tasks for BfArM are described as well as the topics of its recently installed research and development group on prospective risk identification and application safety for medical devices. Results of failure mode and root cause analyses of incident data are presented as well as further data on cases with the result “root-cause analysis not possible”. Finally an outlook is given on future challenges regarding risk assessment for medical devices.