Total Joint Arthroplasty (TJA) of the thumb base is an advancing surgical treatment for osteoarthritis (OA) in the carpometacarpal (CMC-1) joint. While TJA offers improved mobility and faster recovery compared to traditional treatments such as trapeziectomy, the procedure presents challenges in accuracy and precision. Current semi-freehand surgical techniques lack standardized landmarking, leading to complications such as prosthesis misalignment, cup loosening, and ultimately revision surgeries.

This thesis explores the use of laser guidance during surgery as an innovative approach to enhance the precision of prosthesis placement in thumb joint arthroplasty. Through a collaborative design process with surgeons at Reinier Haga Orthopedisch Centrum, a concept for laser-guided surgery was developed. This concept aids surgeons in accurate k-wire placement by improving alignment and reducing intraoperative variability. The final design focuses on integration into the surgical workflow and ease of use during surgery.

Evaluation through interviews, feasibility testing and validation testing demonstrated the potential of the concept to improve accuracy while maintaining surgical efficiency. Future recommendations include further embodiment of the design, cadaver studies for validation, and exploration of additional technologies such as surface mapping. The proposed solution offers a promising step towards reducing complications and improving outcomes in thumb joint arthroplasty.

Keywords: osteoarthritis, thumb joint arthroplasty, total joint replacement, CMC-1 joint, surgical instrumentation, laser-guided surgery, medical product design

The Halo frame is a medical device used to provide cranial and cervical immobilisation for patients with severe spinal injuries. It ensures proper alignment of the spine during healing by stabilising the head and neck through a combination of a halo ring attached to the skull and a vest worn on the torso. While the device is effective, its acceptance among patients and healthcare professionals has been limited.

This lack of acceptance is largely due to the unaesthetic appearance of the frame, which can have a negative psychological impact on patients, along with issues related to comfort, bulkiness, and the difficulty of assembly and adjustment. These factors often discourage patients and doctors from opting for the device, despite its clinical benefits.

The redesigned Halo frame addresses these challenges with a focus on improving aesthetic appeal, comfort, and usability. The new design minimises visual intrusion by using only two vertical rods and an additional set of horizontal rods extending over the shoulders, moving much of the structure behind the head. Carbon fibre rods and a medical-grade plastic vest were incorporated to significantly reduce the weight while maintaining structural strength. Adjustability has been enhanced with a rack-and-pinion mechanism, allowing precise height adjustments even when the patient is lying down. The design also reduces the bulk of the frame and improves the fit, ensuring it accommodates a wide range of body types.

Allowing controlled micromovements in the redesigned Halo frame supports healing by promoting natural bone stimulation, which prevents weakening over time. Research shows complete immobilisation can inhibit recovery, as seen in other orthopaedic devices like knee braces. The frame balances stability and small movements to enhance the healing process while ensuring safety.

Finite Element Analysis (FEA) was conducted to evaluate how deformation in the frame translates to deformation in the spine. Boundary conditions from existing research were used to assess whether the design meets safety and performance requirements, confirming its viability as a medical device. In the re-design, it was determined that the maximum angular displacement in the vertebrae is 6.1 degrees, and the maximum horizontal displacement between two vertebrae is 1.2 mm, confirming the design’s safety and performance.

User feedback played a significant role in refining the design. Orthopaedic technicians and design students provided valuable insights, leading to improvements such as increased adjustability of the horizontal rods and optimised hinge placement for greater accessibility. Additional considerations, such as developing reusable components and enhancing the frame’s visual appeal, aim to increase patient acceptance and sustainability.

Finally, this report outlines key recommendations for further development, including advanced performance testing under dynamic loads, prototyping with actual materials, and focused user studies to refine aesthetic appeal. Early collaboration with manufacturers is emphasised to ensure the design is cost-effective and feasible for production. Finally, steps toward MDR certification are detailed to prepare the product for market introduction.

Children with a Congenital Heart Defect (CHD) need to visit the outpatient clinic regularly their whole lives, often starting from birth. These hospital visits are frequently accompanied by feelings of anxiety and fear, which can have a detrimental impact on a child’s life. In collaboration with the Hospital Hero Foundation and the Willem-Alexander Children’s Hospital, the aim of this project was to design an intervention that reduces children’s feelings (aged four to ten) of fear and anxiety during outpatient visits to the paediatric cardiology department.

Employed Methods
Throughout the project, the following methodologies were employed:
1. Literature research exploring the background of paediatric hospital-related anxiety and fear, and existing anxiety-and-fear-reducing strategies.
2. Interviews with children (with and without CHD), parents, and paediatric healthcare workers to map the current situation.
3. In-depth observations of the current context of an outpatient visit to the cardiology department.
4. The facilitation of creative sessions to generate ideas and concepts, ultimately resulting in the final design.

Home-Based Preparation
Home-based preparation was chosen as the leading fear-and-anxiety-reducing strategy. This strategy focuses on providing paediatric patients with information prior to their hospital visit. Due to the developmental and cognitive levels of the defined age group, the responsibility of home-based preparation lies with the caregivers/guardians of the patients. The following main research question was defined: How can design support children (between the ages of four and seven) and their parents in the home-based preparation process of an outpatient visit to the paediatric cardiology department?

Research Outcomes
Exploring the current preparation touchpoints, practised preparation methods, and the hospital experience from the child’s perspective resulted in the following summarised research outcomes:
• Every paediatric patient and their situation is unique. As a result, every child experiences an outpatient visit differently. Therefore, customised preparation is required.
• Parents encounter barriers during the home-based preparation of their children. Existing preparation touchpoints, including the Hospital Hero application, do not accommodate these barriers.
• Preparation of children should contain context-specific details and focus on sensory stimuli.

Intervention
Based on the research outcomes, a home-based preparation approach was defined. Context-specific triggers of fear and comforting elements were mapped and selected as preparation content. This resulted in the design of an online module that can empower children with CHD and their parents with home-based preparation. The online module was evaluated with parents and healthcare workers and shows promising results. Recommendations regarding improvements and implementation are provided.

Pancreatic cancer is one of the deadliest types of cancer and generally has a 5-year survival rate of 5%. Surgery (pancreatoduodenectomy) is the only form of curative treatment for patients diagnosed with pancreatic cancer. If the tumour is operable, the resectability of the tumour depends on the level of tumour-vessel contact. Based on CT scans, assessing the resectability of the tumour can be critical and demands expertise.

Philips, collaborating with Catharina Hospital Eindhoven and Eindhoven University of Technology (TU/e), has an oncology team called Eindhoven MedTech Innovation Centre (e/MTIC), working on a health care innovation regarding Pancreatic cancer enabled by AI (artificial intelligence) and Medical Image Guiding. This graduation project focuses on this pancreas use case; an integrated imaging workstation is being developed using 3D visualisation and enabling AI to enhance the workflow.

This graduation project focuses on improving healthcare professionals' user experience and interaction within an integrated imaging workstation. The project focuses on visually communicating tumour detection and vascular segmentation, resulting in better diagnosis and surgical planning. The aim is to eventually design a visual language (a design language system guideline) to improve the workflow and experience.

A user review was conducted using videos of user tests performed previously in the pancreas use case. This review led to the usability problems and the user needs of the 3D model in the pancreatic use case. A professional critical study was also conducted, revealing the prototype's strengths and weaknesses.

Eventually, a redesign for the 3D model was developed. This model is focused on showing resectability to improve the workflow. Moreover, uncertainty regarding the tumour size and shape is visualised as well.

Additionally, a DLS guideline for similar applications within Philips focused on medical 3D visualisation was designed at the end of this thesis.

Finally, 3D visualisation, enabled by AI, improves the workflow within a medical imaging workstation.

A problem at the VUmc hospital in Amsterdam is that some patients become unrecognizable after the surgery. It is hard for surgeons to explain during the consultation how and how much the patients will change due to the surgery. Partly, because the surgeons cannot predict if the patient will become unrecognizable. Therefore, they tell them that there is a possibility they change drastically, and with this information, the patients do not know what they can expect. Even if the outcome of the surgery is optimal according to aesthetic and functional guidelines, the mismatching expectations with the outcomes can dissatisfy the patient. Some patients cannot get used to their new changes and do not recover emotionally, resulting in mental problems. Therefore, there is a need for a tool in the consultation room to predict changes in facial recognition per patient and which helps the surgeon to communicate this to the patient.

The changes in facial recognition were noticed at the VUmc, but there was no proof that the orthognathic surgeries actually influenced facial recognition, because no research in the topic was done before this project. This project proves that orthognathic surgeries can influence facial recognition which creates a new field of research. The research in this project shows that not all patients become unrecognizable, it depends on the specific face of the patient and the type of surgery the patient undergoes.

Facial recognition is complex since it depends on who is trying to recognize the patient, how familiar the patient is to this person, and a persons ability to recognize someone can differ per day and is therefore variable. Therefore, a test has been done to analyse the influence of orthognathic surgeries on facial recognition within a familiar group.

Testing a larger dataset would be too time-consuming to test among humans and, therefore, a landmark-based computer recognition method has been used to analyse a dataset of 75 pre- and post-surgical patient pictures. Both tests show that some regions of the face influence facial recognition more than others, as well as specific landmark movements which simulate orthognathic surgeries. Also, facial recognition depends on the face of the patient. Therefore, a concept of a tailored tool was created, called Fraos, showing the predictable changes in facial recognition per patient and helping the surgeon to communicate this to the patient. It also supports the patient in emotionally recovering from the facial changes.

Loneliness, as a social problem, has drawn wide attention of the academic and public. Moreover, loneliness among the elderly is significant. Up to 32% of adults older than age 55 report feeling lonely at any given time. Millions of euro have spent to identify the lonely elderly. With a great interest in social design, the author is intrigued by this issue and thus, initiated the project with an attempt to make a contribution to it with design methods.

In the research phase, extensive literature constructed a holistic view of the loneliness and yielded a new perspective of understanding it. Loneliness is like the destination of the vicious circle between negative social interaction and negative social cognition. Moreover, it may spread through negative interaction. Thereby, the project focuses on social interaction as the entry point for intervention. Through partnering with Vierstroom, one elderly home care company who is also interested in connecting their elderly members, the project finds a context for designer’s intervention. It is activities organized by the Vierstroom and Palet welfare such as bingo game, or care lecture. Investigation of the context revealed dozens of problems and opportunities. There are five pain points highlighted in the elderly activity: the reliance of facilitator, the passive social attitude, the negative social norm, the negative complaining and the one-way communication.

A new relationship between elderly and organization: sports fan and coach
Analysis and ideation provoke a vision that elderly and organization could be like sports fan and coach. With service design methods, the author paves the road to vision by seeing the activity as multiple-layers and sequential interaction. After that, a service strategy is synthesized with four steps for four sub-visions. Moreover, the strategy is translated into 15 design guidelines. Thereby, organizations could adopt the guidelines to enhance their service or generative service ideas in various cases.

There are currently no technological options in the market for the oral care of edentulous population. Dental Robotics, a company already involved in the production of dental care devices for elderlies, is interested in new technological solutions to attend this sector. The design is challenging as it has to meet several requirements: 1) be built upon an existing platform (the Air 1 handle), 2) to demonstrate potential for efficiently clean different mouth morphologies, 3) to use an actuator that requires minimal maneuver and is easily accepted by patients and be practical for nurses, and all these while showing manufacturing feasibility and production scalability. The methodology followed a combination of design thinking and lean startup, meaning a human centered, technology-based iterative and integrative process of prototyping and test. Through this progressive development, diverse strategies were applied, including literature research, field work observations and empathizing with the problem, comparison of market-available alternatives, exploration of materials and prototyping processes, evaluation of effectiveness and acceptance of different design versions, image analyses to evaluate cleaning capacity, manufacturing process, etc. The result is a validated prototype that meets the technical requirements and represents the optimal solution within the explored options; however, future progress could result from optimizing the motion of the Actuator, improve design features to make the assembly easier, explore different arrangements of tufts textures to increase comfort, increase the sample of mouth morphologies to better represent the edentulous elderly population in The Netherlands, to test the effect of the gum cleaner with Laser Doppler Flowmetry to find out if it could stimulate blood flow (Irrigation) on the gingiva, and for how long, and evaluate the long-term impact of this device in the reduction of Residual Ridge Resorption clinical tests. If proven, this could be an added value offered by the company. The proposal for oral care in edentulous elder patients developed in this work proved promising as market product after further performance and manufacturing process refinements.

Patients are becoming more involved in scientific projects, as evaluators, advisors or partners of academic researchers. From a science communication perspective, these experiences are a fascinating laboratory about the challenges of knowledge sharing and exchange between stakeholders with very different perspectives. Little is known about those who facilitate the blending of the experiential knowledge of patients and the scientific knowledge of researchers within these initiatives.

This thesis explores the professional profile of practitioners within patient organizations that are responsible for patient participation in research projects. Their position is analyzed from the perspective of the theory of knowledge brokering, which puts them at the center of the flow of science communication between the stakeholders. While existing literature has studied the emerging role of knowledge brokers in the transfer of scientific knowledge to decision-makers in healthcare, this thesis offers an original perspective on the context of patient participation, and compares the activities, professional knowledge, skills and personal attributes of the practitioners with that of knowledge brokers in healthcare. The needs that the practitioners express in terms of improvement of both their own profession as well as the process of patient participation have been analyzed using the concept of professionalization, which puts the focus on the development of new professional profiles.

A predominantly qualitative approach was chosen to gather reflections of nine practitioners on their current and desired professional profiles. They were selected after identifying Dutch patient organizations involved in participatory research projects. The methodology included semi-structured interviews and a card-sorting exercise inspired by Q methodology in which they were invited to rank skills and personal attributes related to knowledge brokering. The practitioners emerge as “enthusiastic connectors,” who put an emphasis on knowledge brokering activities and skills that foster the interaction between stakeholders, rather than on knowledge management. Many of the aspects they report as being part of their professional profile are consistent with those reported about knowledge brokers in the healthcare sector. However, the particular context of patient participation shapes their specific characteristics mainly related to their closest stakeholder, the patient. The practitioners confirm that academia, policy makers and funding organizations are increasingly interested in patient participation, and call for organizational changes in order to face this demand: increased recognition as a partner by external stakeholders, further internal recognition within their organization, as well as adequate human and financial resources.

The thesis serves to gain both academic insight, useful for developing measures of effectivity of knowledge brokering and further study, as well as practical insight, useful for recruitment of knowledge brokers and further professionalization of knowledge brokering and patient participation processes.