Absorbent mats, abundantly used in hospitals, are integral to maintaining hygiene and cleanliness by effectively collecting and retaining patient's bodily fluids. absorbent mats are available as disposable and reusable products. In the Netherlands, predominantly disposable products are used, and approximately 23 million absorbent mats are employed each year. The abundant use contributes to the Dutch healthcare sector’s substantial impact to the country’s greenhouse gas emissions, waste generation, material extraction, water consumption, and land use. Hospitals and policy makers within the healthcare sector striving to implement environmentally sustainable practices, require current data for informed decision-making. Yet, only two studies have determined the environmental impact of absorbent mats; however, critical environmental metrics are lacking and detail on the contributions of life cycle stages are insufficient. This study addresses these issues by conducting a comparative Life Cycle Assessment, examining eighteen environmental metrics of both disposable and reusable absorbent mats. The primary objective is to not only assess the environmental impact across all their life cycle stages but also to facilitate the redesign of these absorbent mats to reduce their environmental impact. An in-depth cradle-to-grave Life cycle Assessment, utilizing the ReCiPe impact assessment method, was conducted to compare and evaluate the environmental impact of three different disposable absorbent mats and one reusable absorbent mat. The identification of major contributors to their environmental impact, combined with the application of eco-design strategies, facilitated the sustainable absorbent mat redesign. The Life Cycle Assessment findings indicate that reusable absorbent mats are environmentally superior compared to their disposable counterparts, even if the impact of disposable absorbent mats is mitigated by sustainable product redesign. The reusable absorbent mat demonstrates a lower environmental impact score in fifteen out of eighteen environmental metrics when compared to the disposable absorbent mats. The environmental impact of absorbent mats is largest in the use stage for reusable absorbent mats, and in the material production and manufacturing stage for disposable absorbent mats. The redesigned disposable and reusable absorbent mat concepts exhibit a reduced environmental impact, among other factors, attributed to product recycling. Both concepts facilitate recycling by utilizing a single material for the entire absorbent mat, namely wood-derived materials for the disposable redesign and polyethylene terephthalate-derived materials for the reusable redesign. This study has demonstrated the versatility of Life Cycle Assessment in aiding informed decisions-making and providing valuable insights for sustainable product redesign. The outcomes of the Life Cycle Assessment suggest that hospitals should transition to the use of reusable absorbent mats. Furthermore, the redesign findings offer valuable insights into the environmental benefits achievable through the recycling of medical products.

Introduction
Pancreatic cancer is currently the fourth leading cause of cancer death in the United States and has only a 5-year survival rate of 10%. Pancreatoduodenectomy is the cornerstone of curative treatment for patients diagnosed with pancreatic head cancer. Only 20% of the patients are candidate for surgery since many patients present with distant metastases or locally advanced tumours with vascular involvement. Whether tumours are amendable for resection is based on potential vascular involvement with the surrounding vasculature. Assessment of vascular involvement, mainly based on multi-phase computed tomography (CT) scans, requires specific expertise and can be challenging. Computer-aided detection (CAD) and autostereoscopic three-dimensional (3D) patient models might improve accuracy in predicting vascular involvement and improve overall surgical planning. This graduation project aims to assess the added value of autostereoscopic three-dimensional patient models and computer-aided detection for decision support in pancreatic cancer care.

Technical methods
An integrated medical imaging workstation was developed based on the clinical needs of clinicians regarding key concepts of the preoperative planning of pancreatoduodenectomy. This workstation is a hardware and software combination that consists of three main components; 1) a medical imaging viewer showing CT scan with basic imaging functionalities, 2) annotations outlining the tumour and anatomical structures (to simulate segmentations generated by CAD algorithms) that are translated to 3D patient models displayed on an autostereoscopic display, and 3) CAD-derived metrics (degrees and length contact) regarding vascular involvement of the tumour.

Clinical methods
This integrated medical imaging workstation was evaluated in a multi-centre study including 13 expert hepatopancreatobiliary surgeons and one abdominal radiologist. All participants assessed pancreatic tumours in a simulated setting under 3 different test conditions; assessment using only the regular CT scan (CT-condition), assessment using CT and 3D patient models (3D-condition), assessment using CT, 3D patient models and CAD-derived metrics regarding vascular involvement (CAD-condition). A total of 6 patient cases were evaluated, of which 3 radiologically resectable cases (simple) and 3 radiologically borderline resectable cases (complex) with pancreatic tumours near to major vessels. Perceived fulfilment of clinical needs regarding the preoperative assessment, differences in surgical planning decisions compared to baseline, and confidence in clinical decision-making were evaluated.

Results
Clinicians experienced an improved ability to accurately detect pancreatic tumours and determine the degrees and length of tumour-vessel contact under the 3D- and CAD-condition compared to the CT-condition. Additionally, clinicians reported a higher perceived ability to identify, localize and understand anatomical relationships when supported by autostereoscopic 3D models. Lower degrees of tumour-vessel contact were reported under the CAD-condition compared to the CT-condition. Furthermore, clinicians had higher confidence in assessing the need for a vascular resection under the 3D-condition than the CT-condition.

Conclusion
CAD and 3D might improve the accuracy of pancreatic tumour detection and reduce the overestimation of degrees of vascular involvement on radiological imaging. The risk of over-trust in CAD mandates thorough evaluation of the accuracy and use of CAD in prospective studies.

Climate change is a large and global concern. The healthcare sector contributes between 6% and 10% to national carbon emissions in developed countries. Within the healthcare sector, operation rooms are very resource-intensive. A lot of energy, medical products, equipment and pharmaceuticals are required to perform surgery on a daily basis. This report explores methods to calculate the carbon footprint of Dutch operation rooms. Based on these, a tool is developed to calculate total carbon footprint and identify contributing processes. A data collection trial is completed during this development, identifying difficulties in the data collection and calculation process as well as generating some emission results. A tool is designed from the results of this trial. It is based on life cycle analysis, while also including emission factors calculated from sector carbon disclosures. Differences from either one of these carbon emission calculation methods are evaluated and if possible, compared. A final selection of calculation methods for each process is selected and used in the tool. The tool is capable of both internally monitoring carbon emissions over different time periods and comparing emission results with other hospitals. Both these functions can be used to identify emission hotspots, inspire improvements and monitor changes in emissions. Sensitivity of the model to different characterization methods and scope definitions is tested. Ultimately, this tool is aimed to aid in reducing CO2-eq emissions within operation rooms. Recommendations are made to further improve this tool and its data collection procedure.

The operating room and central sterile supply department (CSSD) are two
resource-intensive healthcare departments. Reducing the environmental and financial impact of these departments is of great importance in the global debate on sustainability. Removing unnecessary items from instrument trays may provide a partial solution. However, improvements to tray compositions are often time-consuming, not permanent and not using the full reduction potential. This research compares different methods of medical instrument tray optimization and combines different aspects to create a new methodology. Three models compared and evaluated objective and subjective instrument use percentages and different suggestions for tray optimizations. New tray compositions, based on objective use rates, were discussed with the medical specialists and attuned to their requirements. The result
was then reviewed by the OR-assistants, before making any final adjustments. This methodology is tested for abdominal instrument trays at the gynaecology department of the Leiden University
Medical Center (LUMC). The new trays were evaluated over a test period and missing items were registered during follow-up. Risks to patient safety as a result of missing individual instruments
and chances of missing instruments for different reduction methods are discussed and quantified. Mean use rates of the designated instrument sets are 28.4% (SD=6.43%) for open surgery (n=16) and 47.6% (SD=8.16%) for minimally invasive procedures (n=12). A 37% reduction of instruments is reached across three abdominal trays by removing unnecessary items. Weight of the tray contents is reduced by 31%. During the evaluation (n=7 procedures), mean instrument use for abdominal procedures increased from 28.4% (SD=6.43%) to 46.47% (SD=10.96%) after tray optimization. A reduction based on use rates with a 10% cut-off or based on the recommendations of the medical specialists, induces an 8.7% or 3.9% chance of missing any instrument during the procedure, respectively. Tray content reductions based on OR-assistant suggestions and objective use rates with a 0% cut-off are safe, but do not utilize the complete reduction potential. Different tray optimization methods were compared. Use rates were measured in the OR and expert recommendations were discussed in group sessions. A combination of objective use rates and subjective expert considerations can lead to a significant reduction of the amount of unnecessary items in the medical instrument cycle without harming patient safety. Group consensus amongst medical specialists suggests the most radical reduction of instruments on the tray, but increases chances of missing instruments during surgery. Recommendations based on use rates have to be supplemented by reduction efforts based on the clustering of equivalent instruments. Future work should focus on ways to scale reduction efforts to an autonomous hospital-wide system and teach optimization models to mimic human expert input. It should also focus on exact measurements in the CSSD to estimate reductions in costs and CO2-footprint reliably.