7th Dutch Bio-Medical Engineering Conference
January 24th & 25th 2019, Egmond aan Zee, the Netherlands
10:30   Medical devices & safety
Chair: Ingrid Koopmans
15 mins
The Risk of Sawing in Bone
Jip Pluim, Lucas Jimenez-Bou, Reza Gerretsen, Arjo J. Loeve
Abstract: INTRODUCTION When sawing during autopsies on human remains, fine dust is produced, which consists of particles of sizes that may fall within the human respirable range, and can act as vectors for pathogens, but may also be mechanically harmful. Similar risks may emerge in clinical practice during many kinds of surgical procedures. As adequate protective measures are not always available, it would be worthwhile to know if risks could be reduced by the choice of the saw used. The goal of this study was to explore the potential effects of saw blade frequency and saw blade contact load on the number and size of airborne bone particles produced. METHODS An oscillating saw was applied with various saw blade frequencies and saw blade contact loads on dry human femora at the Netherlands Forensic Institute. A custom-built setup was used to apply continuous and controlled contact loads. Released airborne particles were counted per diameter by a particle counter inside a closed and controlled environment. RESULTS Results corroborated with the hypotheses: higher frequencies or lower contact loads resulted in higher numbers of aerosol particles produced. However, it was found that even in the best-case scenario tested on dry bone, the number of aerosol particles produced was still high enough to provide a potential health risk to the saw operator and anyone assisting in the procedure. CONCLUSION Protective breathing gear such as respirators and biosafety protocols are recommended to be put into practice to protect medical and forensic practitioners from acquiring pathologies, or from other biological hazards when sawing bone or assisting in such procedures.
15 mins
User and context framework to develop new diagnostic devices in the low-resource setting
GYoung Van, Jan-Carel Diehl, Jo M.L. van Engelen
Abstract: Parasitic diseases are the main cause of the global health burden which accounts for over 30% of the Disability-Adjusted Life Years and 15 million deaths annually [1]. Accurate and timely diagnosis is essential to reliable medical treatment that can significantly reduce the risk. However, in low-resource settings, diagnostic tests are usually unavailable or inaccessible [2]. There have been previous researches to deploy new technologies to develop new point-of-care devices or alternative laboratory equipment to increase accessibility of diagnostic tests. While existing approaches put more emphasis on optimising the technical performance, there is a tendency to neglect the different types of end-users and usage contexts. Evidently, disseminating new diagnostic technologies does not ensure the adoption of it. [3]. Without profound user- and context-of-usage analysis, there is a high risk of failure in the adoption and scale-up of the new diagnostic devices. This was shown in the case of malaria rapid diagnostic tests which were developed for the community and primary healthcare level but remained unused in these settings [4]. Amongst different barriers identified in the previous research [4], involving end-users in the research process was considered critical to strengthening innovation and successful adoption [5]. Therefore, we focused our research on the issues related to the end-users and usage contexts to create a user and context framework. The framework will provide a basis for understanding the user and context related barriers and opportunities. Based on the beliefs and behaviours of the end-users [5] and limitations from the infrastructure [6], the findings will be used to draw out inclusive user specifications for a new diagnostic device. We believe that putting additional efforts upfront to user and context analysis will significantly raise the probability of success.
15 mins
3D Printing of Highly Complex Medical Instruments
Costanza Culmone, Paul WJ Henselmans, Gerwin Smit, Paul Breedveld
Abstract: Additive manufacturing (AM), also known as 3D printing, is a technology to directly transform a computer-aided design (CAD) model into a 3D object. This technology is rapidly changing the production methods of medical devices. The additive manufacturing technology enables short-time and low-cost production avoiding the long process of conventional fabrication methods. Fields of applications vary from artificial tissues and organ transplant to the development of personalized orthoses and prostheses. Since the last decades, the interest in producing instruments for diagnostic and surgery is increasing. Using additive manufacturing technologies gives a considerable freedom in terms of complexity of the design. Hence, several research groups are trying to push the potential to the extreme. In the same time, due to the inexpensiveness of such technologies, the additive manufacturing is opening the door to an easier access to the healthcare in remote areas and in the developing countries as well as to a new class of customized disposable instruments for rare diseases and complex anatomies. In our group, we focus on design medical instruments with highly complex functionality for minimally invasive surgery to use in both the laparoscopic and endoscopic procedures. By using additive manufacturing, we are able to manufacture elaborate structures by reducing the number of components and increasing the complexity of the single element. Moreover, by using both vat photopolymerization (VP) and polyjet (PJ) technologies we can play with the thickness of the elements and create flexible structures. For these reasons, we are contributing to a new generation of steerable instruments which can be printed in one printing step in order to reduce the assembly time and the manufacturing cost, increasing functionality and performance.
15 mins
Detecting Magnetic Particles in a Patient, in a Regular Operating Room
Bennie ten Haken
Abstract: Superparamagnetic iron oxide nanoparticles (SPIONs) are used as a tracer to find sentinel nodes in vivo. The principle that we use to locate them is Differential Magnetometry (DiffMag). In DiffMag, the nonlinear magnetic properties of SPIONs are used, enabling selective detection in the diamagnetic patient. We developed a prototype detector for surgical applications that is working with extremely small magnetic fields (~1 mT) and can detect the SPIONs in small quantities (~0.1 mg) inside patient tissue with the diamagnetic properties. We realized a novel magnetic technique to detect particles deep in the patient body, that is usable by the surgeon in a regular operating room. With this novel magnetic technique we aim to enable the application of the sentinel node procedure, in a much broader patient group.
15 mins
Uniforming the Route Around CE Issues in Healthcare Institutions in the Netherlands
Herke Jan Noordmans
Abstract: The new medical device regulation sets additional requirements not only for manufacturers and suppliers but also for healthcare institutions. In the Netherlands, we started from the Dutch Association of Clinical Physics, in consultation with adjoining professional associations, to define a uniform route how to deal with issues related to CE / non-CE status of medical devices or whether it is used within intended use. In this route it is agreed under which circumstances a medical device may be used (regular care, medical research, unique patient, or self-development without alternative). In this route the Medical Device File (MDF) is an essential element to record the design, develop, tests, use and their associated risks. Within this route it is also proposed who or which committee should assess this file at which stage in the route. The CE route is followed by the regular Convenant Medical Technology process. Risks from the CE process should be included or mitigated in this convenant process. Through this CE route we want to clarify for manufacturers outside a hospital but also for self-developed tools within a healthcare institution how to deal with issues around CE. In this way we hope to maximize both quality and safety without losing too much time in bureaucracy due to lack of clarity of procedures or duplication of information within documents.
15 mins
Faltering Medical Instruments and Suboptimal Situation Awareness as Risk-Factors for Surgery
Linda Wauben, Connie Dekker-van Doorn, Johan Lange, Jan Klein
Abstract: Introduction: Despite decreasing rates of healthcare-related avoidable harm, unintended events still occur, especially in the complex-dynamic environment of the operating room (OR). To prevent unintended events from occurring, a Time Out Procedure plus debriefing (TOPplus) was designed and implemented. The goal of this study was to establish risk-factors for avoidable harm and adapt TOPplus accordingly to prevent future unintended events. Methods: OR team members were asked to self-report ‘details’ (remarks and unintended events) about the surgical procedure before introduction of TOPplus (T0 baseline measurement) and six months after introduction (T1). Hospitals joined the TOPplus study voluntarily over time (not pre-selected). Details were registered via paper registration forms and were digitalised and categorized into remarks and incidents (unintended events). Both remarks and incidents where subdivided in subcategories relating to: anaesthesia, surgery, communication, instruments and equipment, leadership, situation awareness, teamwork, perfusion, and TOPplus. Results: In total 8 out of 15 participating hospitals in the TOPplus project completed T0 and T1: 3 academic, 2 teaching and 3 general hospitals. Figures 1 and 2 show the results. Figure 1: Number of self-reported remarks and incidents (unintended events). Figure 2: Situation awareness and instruments; main self-reported incidents (unintended events). Discussion & Conclusion: Defect and incomplete instruments and equipment and suboptimal situation awareness were the main causes of unintended events in the OR and therefore the main risk-factors for patient harm. The number of incidents most probably was higher due to underreporting. Although unintended events relating to a lack of situation awareness can be addressed and prevented by TOPplus, the ‘defect’ instrument and equipment need redesign to further improve patient safety.