Increased capabilities of additive manufacturing technologies have opened up numerous possibilities in mandibular reconstruction surgery. For example, 3D scans can be used to design patient-specific reconstruction plates, resulting in designs that are tailored to prevent plate fracture, wound dehiscence, and malocclusion. However, screw loosening as a result of stress shielding is still an issue. This phenomenon is caused by the mismatch in stiffness between the bone and implant material. The stiff- ness of the titanium in these reconstruction plates can be reduced by using porous microstructures in the proximity of the remaining mandible. However, this makes intuition-based design impossible. This work applies computational tools to optimize the design of a mandibular reconstruction plate with varying microstructure porosity. To achieve this, Topology Optimization (TO) is used that accurately re- solves boundaries utilizing the Interface-enriched Generalized Finite Element Method (IGFEM), which results in a smooth representation of the design. In this work, this methodology is enhanced to result in an even smoother and more accurate boundary. Moreover, additions are made to account for varying material properties in the analytical sensitivities of the compliance objective. The functionally graded designs exhibit significantly higher compliance that should reduce stress shielding. Also, they feature a more porous microstructure near the bone, providing a basis for bone ingrowth. Thus, it is established that enriched TO can be used to optimize the design of mandibular reconstruction plates made out of functionally graded materials that could reduce the risk of screw loosening.

In recent years, there has been growing interest in the magnetocaloric effect (MCE) which is a magneto-thermodynamic phenomenon observed in certain magnetic materials. MCE materials undergo temperature changes when subjected to magnetic fields. Researchers are now exploring the possibilities of utilizing this material in biomedical application technologies, as they offer the potential for non-invasive control of their properties through external magnetic fields. However, there is a lack of research on suitable magnetic compositions that exhibit desired magnetic properties for medical purposes, while ensuring no adverse effects on the cells.

This master project explores the potential of a magnetocaloric (Mn,Fe)2(P,Si)-based compound as a biodegradable membrane for multi-cell separation in organ-on-chip platforms. Mn0.65Fe1.30Si0.37P0.65 compound was selected due to its sharp phase transition characteristics and tunable Curie temperature (Tc), which enable self-regulation of temperature within the therapeutic range, thus preventing potential damage to living cells. The synthesized Mn0.65Fe1.30Si0.37P0.65 compound exhibited a transition temperature of 316 K (43°C) with particle sizes ranging from 1-5 µm. A magnetocaloric wax-based composite was synthesized by integrating these particles with a wax component. Characterization under alternating magnetic fields (AMF) showed a significant temperature rise with higher magnetic concentrations and field amplitudes. At an applied AMF of 9 mT and a frequency of 244 kHz, a sample containing 15 vol.% magnetic particles stabilized at 44°C, effectively maintaining controlled temperatures within the therapeutic range (42-47°C) and efficiently melting the wax without harming living cells. Water absorption tests and SEM imaging further demonstrated the composite's low water permeability and minimal development of microcracks over time. These findings validate the potential of magnetocaloric materials with adjustable Curie temperatures for precise self-regulation of temperature in biomedical applications. The observed high heating efficiency and prevention of overheating offer promising opportunities for controlled thermal activation processes across various biomedical fields.

The dorsal root ganglion (DRG) is an interesting target for neurosurgical pain treatments since it contains the somata of sensory neurons and is relatively accessible, just outside of the central nervous system. Current interventions, such as radiofrequency ablation or neurostimulation, target the DRG with rigid instruments, only tangenting the structure. The goal of this project was to increase the area of influence for neurosurgical instruments by expanding the contact area between the instrument and the DRG. A mechanical solution was designed, consisting of a pre-bend nitinol leaf spring and a rigid injection needle as delivery device. Multiple prototypes were made with various pre-bend diameters and tip shapes. The prototypes with a backbend at the tip and a pre-bend diameter of 5-6 mm were the most successful in curving around a phantom of the L5 DRG in an experimental setup. Future research is needed to incorporate treatment modalities such as neurostimulation and radiofrequency ablation into the mechanical design.

This study explores the impact of different bicycle saddle designs on saddle pressure distribution and comfort in female cyclists suffering from medical conditions affecting the groin area, including Lichen Sclerosus, Lichen Planus, and Vulvar Carcinoma. These conditions can cause discomfort and pain during cycling, leading to a decrease in physical activity and quality of life. The research involved a comparison of four distinct saddle designs, each aimed at reducing pressure in specific areas through partial cutouts or surface depressions. Participants were divided into a case group, comprising 23 women with the aforementioned medical conditions, and a control group of 50 women with no such conditions. Pressure measurements were collected using a stationary bicycle and a pressure mapping saddle cover containing 64 sensors. Additionally, participants completed questionnaires to evaluate perceived comfort and symptom severity. The quality of life (QoL) score was significantly lower in the case group (0.83 ± 0.09) compared to the control group (0.96 ± 0.09, p < 0.001). No significant differences were found between the case and control group in terms of cycling habits. Complaints during cycling were reported by 100% of the participants in the case group and only 8% of the participants in the control group. Pain and numbness were the most reported symptoms for cycling at home. The results indicated significant differences in loaded weight per saddle between the case and control groups (p = 0.001, p = 0.010, p = 0.003 & p = 0.013). In the case group, participants experienced higher pressure. Saddle 2 was favored by 44% of the case group participants for home testing. These findings underscore the need for specialized saddle designs to improve cycling comfort and potentially alleviate pain for women with medical conditions in the groin area.

Treatment methods for spinal disorders involving spinal fusion surgery often entail lengthy and expensive procedures, with a risk of damage to surrounding tissues. Breach detection tools aid in precise pedicle screw placement, thereby reducing the risk of complications or misalignment, and minimizing the need for follow-up surgeries. Accurate placement of pedicles in the vertebrae is crucial in spinal fusion surgery, as improper positioning can result in breaches that potentially harm neural tissues. This study proposes a handheld bone sensing device capable of measuring real-time reflected light from tissue using carefully selected optical elements. The selection of these optical elements was guided by analyzing porcine absorption spectra and conducting Monte Carlo light reflectance simulations. The device is designed to provide consistent real-time feedback by incorporating an electronic circuit optimized to minimize environmental signal interference. A prototype, named the optics-based bone quality sensing device, was developed using electrical discharge machining parts, 3D printed parts, an Arduino Uno, a custom-made printed circuit board (PCB), and off-the-shelf optical components such as laser and photodiodes coupled into optical fibers. Experimental validation with ex vivo porcine vertebrae revealed that the device could not detect sufficient reflected light to differentiate between cortical and cancellous bone. Despite this, the study marks significant progress in creating a handheld bone sensing device that utilizes real-time reflected light sensing minimizing interference. This device represents an important step towards developing tools to assist in precise pedicle screw placement for the treatment of spinal disorders.

Introduction- The global incidence of thyroid cancer has risen significantly, prompting the development of innovative surgical techniques. Transoral thyroidectomy offers a scarless alternative, with the transoral endoscopic thyroidectomy vestibular approach (TOETVA) showing promising results. However, CO2 insufflation during TOETVA can lead to fatal complications. To address these issues, researchers have explored gasless TOETVA methods. Our study introduces a modular articulating retractor integrated with a 5mm camera system, aimed at minimizing CO2-related complications while preserving the benefits of the conventional procedure.
Method- Through a design process comprising problem definition, ideation, and solution creation. A detailed digital CAD design is developed based on force measurements obtained from a preliminary cadaver study. Subsequently, a functional prototype is created and subjected to pre-clinical testing using Thiel-embalmed and fresh frozen cadavers.
Result- Force tests determined a mean force of 4.73N across cadavers, with 5.29N necessary for optimal skin elevation. SolidWorks simulation indicated maximum stresses of 128.10 MPa and 113.80 MPa in articulated and horizontal positions. Backdrivability of articulation occurred at approximately 4N applied force. Assembly and disassembly tasks demonstrated mostly normal distribution, with significant differences observed between initial and final assembly attempts. Despite successful procedure performance, challenges included endoscope removal limitations and partial functionality constraints during articulation within cadavers. Overall removal time averaged 3.2s, with a maximum of 4.1s.
Conclusion- The gasless TOETVA procedure was performed successfully with sufficient visualization for the surgeon. While achieving three of our four objectives, including the design and compatibility with standard endoscopic cameras, limitations prevented direct comparison with conventional CO2-based TOETVA methods. Despite this setback, the initial incorporation of our instrument into surgical procedures demonstrates promise. However, further research is imperative to compare its performance against conventional methods, validating its efficacy and potential in clinical practice.

Accurate placement of screws in spinal surgery is vital to mitigate risks like instability, nerve damage, or spinal cord injury, which can lead to various complications such as pain, sensory loss, muscle weakness, or paralysis below the injury site [33]. However, success rates in screw placement vary widely, ranging from 27.6% to 100% [56].

Advanced techniques, like pedicle screw placement (PSP) with enhanced guidance systems, aim to provide surgeons with better spatial awareness to prevent cortical breaches. Various guidance methods,
such as fluoroscopy, computer-assisted techniques, neurophysiological monitoring, and Electrical Impedance Spectroscopy (EIS) enabled by the PediGuard, have been developed and utilized in spinal fusion surgeries [18]. Despite their efficacy in reducing complications, these systems have limitations such as increased radiation exposure, prolonged surgery time, or lack of real-time feedback.

This study compares two sensing techniques, Electrical Impedance Spectroscopy (EIS)) and Diffuse Reflection Spectroscopy (DRS), for spinal fusion surgery. Both methods are employed to detect cortical
breaches during PSP by distinguishing between cancellous and cortical bone. Before experimentation, certain gaps in understanding must be addressed, including exploring the working principle of EIS for
vertebrae tissue and developing classifiers for both single and multiple frequencies. Additionally, efforts are made to create a vertebrae phantom with realistic electric and optical properties. EIS demonstrates an increase in impedance for cortical bone compared to cancellous bone due to the latter’s weblike structure with highly vascularized yellow bone marrow. Single-frequency analysis outperforms multiple-frequency analysis in distinguishing between vertebrae tissues. However, the development of a better model or the use of multiple single-frequency classifiers may enhance predictive
accuracy. Despite attempts to create an accurate vertebrae phantom, limitations in adjusting dielectric properties result in the utilization of the best-fit recipe.

Comparison between EIS and DRS reveals both are effective in detecting cortical breaches and tissues, with DRS exhibiting a longer look-ahead distance. EIS operates more like a step function, making it susceptible to distortions, suggesting DRS outperforms EIS in spinal fusion surgeries.

Minimally invasive medical procedures often require catheters, endoscopes and other devices to maintain position at a specific site in the body, to cut and remove tissue or for diagnostic purposes. Due to tool force exerted by the surgeon or the natural processes of the body, such as the activity of the heart or the lungs, the inserted device can dislodge or migrate from its intended location. Existing solution focus on stabilizing the tip, following high localized pressure, this can create tissue damage or even perforation. Hence, it can be beneficial to create stabilization over the full length of the catheter. I investigated the use of electroadhesion i.e. using electricity to adhere to the tissue wall. I created a scaled-up, flexible, electroadhesion stabilization proof of concept, consisting of two opposite-charged electrodes in a helical pattern, embedded in silicone rubber. Friction experiments were performed on the catheter proof of concept on two copper half-tube substrates. One of the three flexible scaled-up catheter samples showed an increase in the average dynamic friction coefficient of 10.2% between 0 and 2500 V for the 22 mm diameter substrate. The two other samples showed no or limited increase in friction, attributable to manufacturing differences. Predicting coating thickness is essential, as the coating is the determining factor for the performance of the electroadhesion device. The catheter showed potential, however, improved adhesion performance is required for feasibility on a smaller scale.

This graduation project is part of a double degree program for the master’s in Biomedical Engineering and Communication Design for Innovation, conducted at the Cardio-Respiratory Engineering And TEchnology laboratory (CREATElab) in Melbourne, Australia.

Cardiovascular diseases remain the leading cause of death globally, with out-of-hospital cardiac arrests often resulting in poor outcomes due to prolonged periods of compromised blood flow. Prehospital extracorporeal cardiopulmonary resuscitation (pECPR) offers a promising rescue intervention to reduce treatment delays. This design study improved the RApidly DEployable (RADE) ECPR kit prototype 1.0, which demonstrates full ECPR equipment compatibility for prehospital settings while streamlining the treatment workflow. Based on clinical insights, prototype 2.0 aimed to optimize the RADE ECPR kit’s speed and performance. Testing with clinicians at the Alfred Hospital in Melbourne showed significant improvements in deployability, equipment organization, and overall usability compared to the conventional pECPR suitcase and prototype 1.0.

Additionally, this study examined the impact of leadership absence on innovative scientific performance. While the effects of leadership gaps on research teams remain underexplored, the departure of the CREATElab’s Director provided a unique opportunity to evaluate the challenges and consequences of such disruptions. Using a mixed-method approach, the findings revealed that leadership absence hindered collaboration and motivation, shifting lab dynamics toward task-oriented isolation. Shared decision-making and distributed leadership were identified as communication strategies to sustain innovation during such gaps, with The CREATElab Challenge offering a gamified solution to strengthen connectivity and morale.

The studies highlight the critical role of engineering design optimization in improving outcomes for cardiac arrest patients and underscore the importance of adaptive communication strategies in sustaining scientific innovation, particularly in challenging circumstances.

Background: Laparoscopic surgery has improved patient outcomes and reduced healthcare costs in high-income countries but faces implementation barriers in low -and middle-income countries due to reliance on carbon dioxide insufflation, expensive equipment, and specialized personnel. Gas Insufflation-Less Laparoscopic Surgery (GILLS) provides an alternative by lifting the abdominal wall without carbon dioxide; however, expensive laparoscopes and assisting staff to operate those remain necessary. Hence, the need for a device that substitutes for the gas insufflation and laparoscope was identified.

Methods: This thesis aimed to integrate an abdominal wall lift (AWL) device and imaging system to enhance GILLS and Single-Incision Laparoscopic Surgery (SILS). Using a context-driven approach, the design focused on surgeon visibility, patient safety, cost-effectiveness, and user-friendliness. The device was developed using inexpensive, readily available components and conventional production techniques. The validation included seven verification tests and an expert user evaluation.

Results: The lifting device consists of a stainless steel tubular hook with LED lighting and a $5$ MP camera module. It can be inserted in the abdomen through a small incision, lifts the abdominal wall, and creates a clear view inside the abdominopelvic cavity. An aluminum prototype had sufficient structural strength, was cost-effective, lightweight, and compatible with existing AWL systems, but it generated excessive heat, was not waterproof, and lacked a functional imaging system. Evaluation by a GILLS expert highlighted design strengths while emphasizing three areas for improvement: the frame's shape, the imaging system, and the sealing technique.

Conclusion: This study illustrated the potential of integrating an abdominal wall lift device and imaging system despite the substantial constraints of the current tubular design. The cost-effective alternative eliminates the reliance on carbon dioxide gas, expensive laparoscopes, general anesthesia, and untrained assisting staff. Therefore, development should continue to improve access to laparoscopic surgery worldwide.

The prevalence of chronic and complex wounds is high in low- and middle-income countries (LMICs). Due to the lack of adequate treatment wound conditions are likely to worsen. Improving access to wound care in LMICs is crucial for enhancing the quality of life for the people living there. Vacuum- assisted closure (VAC) therapy is an effective treatment for chronic and complex wounds. By applying a negative pressure to the wound the healing process is promoted. However, due to the high cost of VAC devices, their availability in LMICs is limited. A. Knulst works as a biomedical engineer at GPH and recognized this problem. In GPH the AquaVAC, a converted aquarium pump, is used to be able provide VAC therapy to patients. The use of the AquaVAC is not meeting the users’ requirements. Recognizing this problem, A. Knulst initiated the WOCA project to develop a VAC device tailored for LMICs. Over the past three years, the project has progressed to creating three simple yet functional prototypes using locally available materials in GPH. Based on the findings of A. Knulst a suitable next step for the WOCA is determined to conduct a clinical trial to evaluate the WOCA’s effectiveness in wound healing.
Designing the goal of this graduation project; preparation of the WOCA for the performance of a clinical trial conducted in GPH. Based on analysation of this goal preparation of the WOCA consists of veri- fication, and validation of the design requirements, verification of the applicable ISO-criteria, and the performance of a risk assessment. By making a redesign the current WOCA at GPH will also be made compatible with these stated requirements.
By making a redesign during this graduation project the canister is implemented and the noise is re- duced for the WOCA. This new version of the WOCA is verified for its design requirements as well as validated, also the applicable ISO-norms are verified and a risk assessment is performed.
Based on this performed effort it is shown that the WOCA is exceeding the allowed noise level deter- mined to be reached before the WOCA can start the clinical trial. Furhtermore, recommendations have been given for additional validation and verification of the WOCA before conducting the clinical trial.
Steps have been taken during this graduation project to improve the access to wound care in LMICs by a contribution to the open-source-publication of the WOCA device, and the development of a study protocol for the performance of a clinical trial.

Introduction - Surgical robotic systems are increasingly valued for their precision and benefits to patients and surgeons, yet traditional designs rely on costly, limited-use, cable-driven instruments that require frequent replacement and specialised cleaning equipment. To address these issues, the Sustainable Surgery & Translational Technology group MI & BITE developed the Advanced Laparoscopy Robotic System (AdLap-RS) with modular shaft-actuated tip articulation (SATA) instruments. Their modular design allows for disassembly, easy cleaning, and part replacement, enhancing reuse potential and lowering operational costs. With the substantial environmental impact of surgical activities, reusable SATA instruments also offer promising sustainability benefits. However, inconsistencies in life cycle assessments (LCAs) applied within the surgical field raise concerns about their reliability, complicating accurate environmental assessments of this innovative technology.
Goal - This research aims to assess the environmental impact of the reusable SATA instrument technology for robotic surgery through a robust comparative LCA while simultaneously informing sustainable design choices during the SATA instrument technology’s ongoing development.
Method - The initial phase of this research included a literature review and a survey among European Association of Endoscopic Surgery (EAES) members to identify reliability challenges in applying LCAs to surgical instruments. Insights from this phase informed a robust comparative LCA, assessing the environmental footprint of one of the reusable SATA instruments against its traditional limited-use counterpart, which also functioned as an eco-design evaluation by applying a circular eco-design approach.
Results - Findings from the first part showed a significant gap in LCA usage in surgical decision-making, largely due to limited familiarity and trust in LCA findings. The absence of a standardised, user-friendly LCA methodology tailored to the complexities of surgical instruments further complicates accurate assessments in this specialised domain. Comparative LCA results revealed that the reusable SATA instrument reduces climate change and energy impacts by over 50% compared to its limited-use counterpart. For both instruments, the use phase represented the largest contributor to environmental impact, primarily due to the energy-intensive disinfection and sterilisation cycles required before each reuse. The eco-design evaluation recommends prioritising modularity and disassembly improvements to optimise tray load capacity and reduce reprocessing impacts.
Conclusion - While this study robustly indicates the sustainability benefits of the innovative reusable SATA instrument technology for robotic surgery, capturing the full complexity of surgical instruments in LCAs remains challenging. Addressing this will require stakeholder engagement, targeted LCA training, refined LCA methodologies, and comprehensive review processes tailored to this specialised field.

Background: The global overuse of Caesarean sections (C-sections), especially in high-resource settings, and the underuse of assisted vaginal deliveries in low-resource regions highlight the need for improved Vacuum-Assisted Delivery (VAD) training tools. Existing phantoms, such as "Lucy and Lucy’s Mum," suffer from anatomical inaccuracies and limited biomechanical realism, restricting their effectiveness. This project aimed to design a new, cost-effective VAD training phantom that addresses these limitations by providing more accurate anatomical structures and biomechanical responses.

Design and Manufacturing: The final phantom design utilised Polylactic Acid (PLA) and FDM 3D printing techniques for solid parts and Ecoflex™ 00-30 silicone reinforced with 20 Denier nylon fabric for simulating the pelvic floor muscles and their biomechanical behavior during childbirth. The fetal head was constructed using PlatSil® Gel-25 silicone for the inner deformation core, and Ecoflex™ 00-30 reinforced with 80 Denier nylon fabric for realistic scalp deformation. Additionally, the phantom's modular design and aluminum-made supporting frame allowed easy replacement of parts for long-term use and more flexible phantom deployment.

Validation Results: Two validation phases were conducted. In the first phase, 5 gynecologists provided feedback, identifying issues with vacuum cup application and some biomechanical behaviors. These issues were fully addressed in the final design. The final validation, conducted by one single expert, confirmed that the vacuum cup application issue had been resolved. However, a new issue related to the palpation of the ischial spine was identified. Quantitative testing measured traction forces and pulling angles during VAD, confirming that the phantom accurately replicated clinical behaviors. The overall performance was highly rated.

Conclusion: This newly developed VAD training phantom mostly overcomes the critical limitations of existing models by enhancing both anatomical accuracy and biomechanical realism. The modular and cost-effective design ensures flexibility and allows for use in a wide range of obstetric training settings. However, the cost per training has yet to be fully evaluated, and further research is needed in this regard. Both qualitative expert feedback and quantitative testing confirmed the phantom’s effectiveness in improving VAD training. While the palpation issue identified in the final validation remains to be addressed, the lack of comprehensive data on specific anatomical and biomechanical properties continues to hinder the development of even more accurate models.

Background:
An endomyocardial biopsy (EMB) is an invasive procedure where biopsy samples are taken from within the heart for diagnosis of different myocardiopathies and or heart transplant rejection monitoring. During EMB procedures, a minimum of five tissue samples are required to be taken from the heart wall for investigation.
Current bioptomes are not able to retrieve more than one sample at a time and therefore need to be re-inserted at least four times. This can lead to complications such as air embolisms. The goal of this design study was to develop a novel cardiac bioptome for endomyocardial biopsies that can take and store multiple biopsy samples during a single insertion.

Design:
The bioptome developed in this study had two major functionalities, resection of myocardial tissue and storage of multiple tissues. Each functionality could be divided into multiple sub-functionalities. From these functionalities the design requirements followed. Afterwards, the alternatives for each subfunctionality
were explored. For the tissue resection, different possibilities for the method of resection, position of the resection tool, direction of resection forces, and motion of resection, were explored. For tissue storage, different possibilities for the storage system, tissue transportation, and sample loss prevention were explored. Following this exploration, multiple design concepts were devised. Two of these concepts, the ’corer’ concept and ’ovipositor’ concept were developed further. These two concept were compared and the ’corer’ concept was chosen as the most viable option. Prototypes of this concept were developed and tested for the functioning of its working principle for tissue resection and storage and for the functioning of the actuation mechanism.

Results:
The experiments showed that the end-effector of the bioptome works as expected and that thus the working principle of the ’corer’ concept for resection and storage of biopsy samples functions as intended. The experiments also validated the functioning of the actuation mechanism within the handle. The experiments however also showed that the flexible shaft was unable to correctly transfer the motion from the actuation mechanism in the handle to the end-effector.

Discussion & conclusion:
More suitable materials are required for future prototypes to improve motion transfer. Furthermore, a steerability functionality should be added to the design to make the bioptome fully functional for EMB procedures. The final design should be tested in an environment more closely resembling the clinical scenario. If these tests are successful, it can be concluded that the bioptome can indeed improve endomyocardial biopsy procedures.

The sterile packaging of instrument trays containing medical devices is a critical step in the sterilization process for various medical and industrial applications. This process involves wrapping instrument trays with nonwoven polypropylene sterilization wrap, which plays a crucial role during and after sterilization. Traditionally, the loose ends of the wrap are secured using autoclave tape. However, the presence of this tape poses a risk of recycling contamination when the wraps are disposed of for recycling. Additionally, in some cases, the autoclave tape has been found burnt at the end of sterilization due to excessive use during the packaging process. This study aims to design and develop a prototype sealing device that eliminates the need for autoclave tapes while maintaining the integrity of the sterile barrier system. During this study, two prototypes of sealing devices were developed: one utilizing ultrasonic sealing technology and the other using impulse sealing technology. The ultrasonic sealer is sourced from a cold-fusion sealer, while the impulse sealer is obtained from a plastic packaging device. Both devices are upgraded and repurposed as per the drawn-up requirement specifications and development criteria. To validate the prototypes, a product characterization test is conducted optimizing the seal time settings based on seal strength tests following ASTM F88/F88M-21. The optimum seal strength, measured using the T-peel test, is determined to be 1.21±0.05 N/mm for the impulse sealer and 0.93±0.08 N/mm for the ultrasonic sealer at the optimized seal time for a test sample width of 30 mm. This is succeeded by, a demonstration of the prototypes at Maastad CSA in Rotterdam, assessing the usability and functionality of these devices. During the demonstration sealed sterile packages were made following a standard envelope-wrapping approach. Replacing autoclave tapes with the seals at the critical points to secure the wrap. Feedback is collected from employees regarding the new method of packaging. Two sealed sterilization packages produced following the use of both prototypes are subjected to a trial run in an autoclave for sterilization testing. The seals proved to be effective in withstanding the sterilization process without compromising the package's integrity.
The results of this study contribute to sustainability efforts in the healthcare sector by offering a more efficient and environmentally friendly approach to maintaining the sterility of reusable medical devices.

Annually, around 180,000 cardiac ablation procedures are performed as a result of people experiencing cardiac arrhythmia’s. During this ablation procedure, an ablation catheter is used to scar the problematic cardiac tissue after which the arrhythmia will stop. The ablation catheter is discarded after one single use. Incineration of these ablation catheters not only means destruction of valuable product, but also additional carbon emissions and pollution. The goal of this research is to design a novel disassembly method for the Thermocool Smarttouch SF Uni-directional Catheter (TAC) to enable extraction of the most yielding parts and/or materials. By means of a Hotspot Map and a part-specific cost estimation the most yielding parts (or PoIs) of the TAC were determined to be the shell, the ring electrodes and the electronics unit. The novel disassembly method was designed with those PoIs in mind and consists of two separate entities: a disassembly prototype (designed to enable extraction of the determined PoIs) and an ultrasonic cleaning stage (to further purify the extracted PoIs). The novel disassembly method was validated and indeed proved to be extracting the PoIs in a more successful, pure, and reasonably timely way compared to a previously performed rough disassembly. Therefore, the outcome of project is successful. However, a critical note must be introduced. Sustainability-wise the outcome is promising, however, from a business standpoint this could be more difficult. Almost all extracted PoIs will be damaged to some extent, and rules say only virgin materials can be used for the development of new catheters: only the costs of the extracted raw material will be yielded. All value added during the manufacturing stage is lost. Taking into account the additional costs of disinfection, shipping, labour and further reprocessing methods, this novel disassembly method would possibly cost more than it would recover. Other opportunities like multiple uses, detachable (sub)assemblies or alternative business cases should be explored.

Brachytherapy is a type of internal radiation therapy that is used to treat cervical cancer. It involves the application of a radioactive source in close proximity to the tumour. This can be done either by directly inserting the source into (or close to) the tumour using interstitial hollow needles, or by loading the source into an intracavitary applicator that is placed in the vaginal cavity. Standard applicator types may lead to suboptimal radioactive source placement, possibly resulting in underexposure of target volumes and overexposure of organs at risk, especially in advanced cancers. Customised applicators and optimised needle channels based on the patient's MRI/CT data could enhance conformity between target volumes and prescribed isodose. Hence, the goal of this project was to develop and validate a design for a 3D-printed brachytherapy applicator which geometry is based on the patient's vaginal cavity and which features optimised interstitial needle channels based on the patient's anatomy and tumour location.

Various analyses have been conducted which have led to the establishment of a list of requirements for the applicator design. Based on this list of requirements, two conceptual designs have been presented: one fully 3D-printed design and one design that is clicked on the Geneva ovoid tubes. Through the creation of prototypes, these conceptual designs have been refined into two final designs which were manufactured in PA12 using selective laser sintering. The dose attenuation properties of PA12 were evaluated and compared to that of water. Furthermore, the potential needle positions within the proximal end of both designs have been analysed. For both designs, a final prototype based on a phantom's vaginal cavity geometry has been created. The usability of these prototypes has been tested by three radiotherapist-oncologists, who also provided feedback on the designs. Upon analysing their feedback and the outcomes of the other evaluations, recommendations for future designs have been formulated.

The conducted dosimetry experiment yielded a maximum difference of 0.8% between the average percent dose depth curves of water and PA12, which can be considered a water-equivalent response. This allows PA12 to be used as the material for the applicator. The result of the potential needle position analysis suggest that the first design provides more space for personalised needle channels in the top of the applicator compared to the second design. The three radiotherapist-oncologists validated the usability of both final prototypes.

Two designs of a patient-tailored 3D-printed brachytherapy applicator containing optimised interstitial needle channels based on the patient's anatomy and tumour location have been presented, produced and validated. Based on the outcomes of the conducted evaluations, there can be concluded that the first concept shows the most promise to be used as a design for a patient-tailored 3D printed brachytherapy applicator. However, to ensure the proper functioning of the working principles, further development is required. If the recommended improvements are implemented, the design has the potential to be used as applicator in the treatment of cervical cancer.

Models for oxygen transport in preterm infants can aid the development and evaluation of automated oxygen controllers by providing insight into the FiO2-SpO2 response and enabling virtual trials. A computer simulation model of oxygen transport in preterm infants is developed and FiO2-SpO2 responses in preterm infants are investigated. The model consists of a respiration and circulation submodule, interconnected by a pulmonary gas exchange submodule. Literature-based parameter ranges are provided. The model's ability to reproduce a patient's FiO2-SpO2 response, be generalised to different FiO2-SpO2 responses, and replicate physiological shunting and apnea scenarios is investigated. FiO2-SpO2 responses in preterm infants exhibit high variability and few responses are found stable. The model could be calibrated to specific FiO2-SpO2 responses using literature-based parameter ranges and could replicate physiologically expected shunting and apnea scenarios. The calibrated model could not be generalised to another FiO2-SpO2 response. The developed model for oxygen transport in preterm infants is a useful, modular, well-documented framework that can be used to develop and evaluate automated oxygen controllers.