This research critically analysed the manufacturing process of a loader bucket with grapple. Such buckets are commonly used to unload dry bulk materials such as wood chips. In order to do this as quickly as possible, these buckets transport tonnes of material each cycle, the buckets themselves have a mass of tonnes too and can be as tall as 4 metres. These buckets are built to order as one-offs or in small batches, optimized for the needs and wishes of the customer. The goal of this research was to reduce the manufacturing lead time of such a bucket from 14 days to ten days or less. The bucket design was changed to accommodate a solution to the problem, but such a change should not increase the module’s weight by more than five percent, nor reduce its functionality in other ways. Each bucket has to remain specific to each customer and their requirements. This research first analysed these requirements and available variations in the bucket design. Following this, the operations in the manufacturing process were identified and analysed with regards to their criticality in the total lead time. Each operation was evaluated regarding its impact on the overall lead time, as well as the dependence on resources available in the factory, such as machinery like a milling machine. Furthermore, the dependency of other operations was also taken into account. According to these factors, the operations with the highest impact on the lead time were identified. From this, various lead time reduction methods were proposed which reduce the impact of these critical operations on the overall manufacturing process. By parallelizing the part with which the manufacturing of the bucket starts, the lead time could be reduced to just more than ten days. To reach the ten day goal, this parallelized part also had to be manufactured more efficiently. For this, six redesigns of the part were devised which do not require machining. These were evaluated in a survey among six employees from the engineering, planning and manufacturing departments. The most promising designs could reduce the expected lead time of the part itself by two days. By combining the suggested parallelization, along with the shortened manufacturing of the mounting plate without machining, the goal of a lead time of ten days could be achieved.

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.

Colonoscopy is a widely used endoscopic procedure to diagnose colorectal cancer (CRC) which is considered the fourth most common cancer in the US and the second most common cancer in Europe. Colonoscope, used in colonoscopy, consists of a thin flexible hollow tube that is inserted into the rectum of a person and propagated through the entire colon. The disadvantage of the current procedure is that the colonoscope has to be pushed from outside to move through the colon resulting in recurrent looping of the colonoscope due to buckling. Recurrent looping inflicts the risk of tissue damage and is responsible for approximately 90% of the pain experienced by patients during colonoscopy. Research was carried out to create self-propelling colonoscopes which would eliminate the force required to push the device from outside. Inspirations were taken from the locomotion of earthworms to develop self-propelling colonoscopes however, the device’s propulsion was hindered due to friction and low axial stiffness of the colon wall. In this study, a proof of concept for a self-propelled colonoscopic device inspired by the ovipositor of wasps was conducted which resulted in the development of a prototype. The prototype was tested in a colon-simulated environment and it was able to successfully propel through the prepared colon phantom after an initial manual run through the colon phantom. The requirement of an initial manual run was speculated to be due to the capillary adhesion and uneven oil spread in the colon phantom. The device had an average velocity of around 5.68 mm /s inside the colon phantom with an average efficiency of 72.5%. In the future, the prototype has to be tested in an actual colon to assess its functionality and evaluate the propulsion efficiency of the prototype in a real colon.

Goal: Nerve injury is a typical complication of a fasciectomy, a surgical treatment for Dupuytren's contracture. This research focuses on the creation of a surgical device to prevent this medical complication.
Design: A mechanical feedforward-based device with a spreading and cutting mechanism was proposed. Stretching the target tissue causes a larger biomechanical difference between this tissue and the nerves. This helps to avoid damaging the nerves during the dissection phase. The DisDis prototype with a precision handling grip was develop. It uses a nitinol tube for the spreading mechanism and a conventional scalpel for the cutting mechanism.
Evaluation: The performance and ergonomics of the prototype are disappointing, compared to the conventional fasciectomy dissection method. Despite this unfavourable result, it is thought that mechanical feedforward-based devices could be still make a positive impact.

Treatment of prostate cancer can be done by performing brachytherapy, where radioactive seeds are transperineally implanted in the prostate via needles. A known problem during treatments with needles is the risk of targeting errors caused by the deviation of the needle from the planned path in the prostate. One of the main sources of this error is the displacement of the prostate due to insertion of the needle. Often, stabilisation needles are used to stabilise the prostate, however, stabilisation needles alter prostate properties, damage tissue, and do not fully reduce prostate displacement. Therefore, in this study, we propose and evaluate an alternative solution that stabilises the prostate without additional tissue damage. The stabilisation solution is a modular suction cup referred as the ProSTATIC, which can be transperineally inserted via a 5 mm incision to attach to the prostate within the rectoprostatic space. The ProSTATIC has a multi-holed design consisting of three structural layers with their functionality; (1) the top to maintain the pressure inside of the suction cup and provide for structural stability, (2) the footprint to adapt and form a closed seal with the prostate surface, and (3) the self-regulating valves to increase the attachment reliability on irregular surface textures. For the footprint, we experimented with micro-patterns and suction hole sizes to increase the overall grip force. The prototype was completely fabricated out of biocompatible and ultrasound-compatible silicone rubber using mould casting. An experimental evaluation showed that the self-regulating valves work only on healthy prostate phantom. On healthy-tumorous and full tumorous tissue phantoms the suction holes deform, hindering the optimal working of the valves and leading to air leaks. Furthermore, only the prototype with the base footprint with enlarged suction holes (from 2 mm to 3.2 mm diameter) and radial ridges was able to generate a maximum grip force higher than the required 5 N for stabilisation and demonstrated that prostate displacement was reduced by 75% during needle insertion without the use of the ProSTATIC. The prototype proposed in this study forms an initial breakthrough in safe and reliable volumetric stabilisation of the prostate during brachytherapy.

Prostate cancer is the second most frequently diagnosed cancer in men. A minimal invasive treatment for prostate cancer is transperineal laser ablation (TPLA), which involves inserting a needle containing a laser fibre into the prostate to induce local cell death. The ovipositor of the parasitoid wasp offers a solution to challenges in TPLA, as the wasp can penetrate substrates with zero net external force, minimising the buckling risk and tissue damage. This paper presents the WASP, a design and prototype of a manually actuated needle for TPLA. The actuation mechanism of the WASP transfers a torque while allowing a low-friction translation in the positive y-direction, enabling the needle to travel through stationary tissue. An integrated cam mechanism allows repetitive motion of the needle rods actuated by a single rotation of the urologist. Evaluation of the WASP showed successful travelling through gelatin concentrations up to 15 wt%, a stiffness comparable to human tissue. The WASP generated a small net push force (Fpush = 0.18 N) and cannot be considered fully self-propelling. Nonetheless, the net push force is notably reduced compared to manual needle insertion and effectively prevents buckling. A performance experiment showed a lower average slip ratio compared to previous studies, which may suggest that a small net push force is beneficial if buckling is prevented. Future steps contain implementing user research and a steering mechanism, to continue innovating minimally invasive surgery for prostate cancer.

Pectus Excavatum (PE) is a common deformity of the thoracic wall, characterized by a depression of the sternum. In the current golden standard for surgical correction of PE, the deformity is instantaneously corrected, causing severe and prolonged post-operative pain. The goal of this study is to design and validate a novel implant to slowly correct PE over time and minimize post-operative pain. A
new procedure was developed called SCARPE: spring-loaded continuously actuated repair of pectus excavation. During the SCARPE procedure, an implant continuously applies a small force on the posterior surface of the sternum. The continuous force is just large enough to stimulate cartilage remodeling and correct the deformity in two years. The SCARPE implant uses two symmetrically
located tape springs as force generator. A tape spring is a thin sheet of metal with a constant cross sectional radius. When subjected to sufficient bending, a tape springs starts to buckle and applies a constant bending moment. The resultant force can be controlled by adjusting the fold location of the buckled tape spring. Adjustments are non-invasively actuated by an external drive mechanism that creates a rotating magnetic field.
A proof-of-concept experiment was performed to investigate the force displacement relationship (FDR) of a tape spring mechanism in various conditions. It was found that the elevation force increased with spring size, number of layers and thickness. Furthermore, the FDR of the tape spring mechanism showed a unique curve for each fold distance, but was equal for the number of spring layers. Only three layered tape springs, with layers fixed together, applied an average elevation force large enough to correct the PE deformity in two years. None of the tape spring configurations, however, could adhere to all requirements simultaneously.
Although the tape springs could achieve a constant force within the force boundaries, some challenges arose. Mainly, the small margin towards the lower force boundary, delamination and anatomical constraints pose a problem. In its current form, the SCARPE implant is not yet suited for clinical application, but is to be considered as a novel approach towards PE repair. Several recommendations are presented for optimization, as well as alternative design proposals for future research.

Vitrectomy is an often performed procedure during eye surgery and requires a high-precision vitreous cutter. The production of these precise and lightweight vitreous cutters sets high demands on the manufacturing process. Trained technicians must assemble the device step by step and continuously check and validate the manufacturing process. Additive manufacturing on the contrary allows for non-assembly mechanisms that can be printed at once without requiring any post-assembling steps. However, a high-speed vitreous cutter design suitable for 3D Printing is not yet presented. This research aimed to deliver a 3D Printed driving mechanism design for a high-speed reciprocating needle used during vitrectomy that does not require post assembly steps from trained technicians. It was established that the driving mechanism should reciprocate two concentric needles by air pressure to cut vitreous. Currently used actuators are investigated and a prior attempt for a non-assembly vitreous cutter is analysed. The diaphragm and bellow-based design were considered a potential solution path. A suitable design for both potential solution paths is made. The bellow design consists of an inner and outer bellow to allow the passage of the needle. The diaphragm concept is already used for the first and only attempt to produce a non-assembly vitreous cutter. This prior attempt is further analysed and it became clear the damping of the diaphragm needed to be decreased to increase the speed of the backward motion. Therefore, a planar spring is added to the dual flat diaphragm design. Finally, the spring-reinforced dual flat diaphragm concept is selected for continuation and tested by using PolyJet prototypes. Tests are executed to determine if the requirements could be met, especially focussing on the speed and force requirements. Different spring shapes and thicknesses are tested. It became clear that the behaviour of the spring-reinforced diaphragms is suboptimal. The return time is higher than preferred and damping is still present in a large extent due to hysteresis. To improve the design it was decided to continue with tests where the start position is relocated to form a pretension and overcome the damping seen especially at the last part of the return stroke. Pretension appeared successful and showed a 98% decrease in return time, but the requirements for the speed could not be obtained. Altering the thickness of the spring led to a sufficient high backward force but did not show direct influence on the speed of the backward motion. Overall, a non-assembly vitreous cutter driving mechanism is made but not all requirements could be met. Exploring design directions which do have some drawbacks should be considered to offer a solution in the near future. Designing a driving mechanism that also requires 3D Printed flexible material, first requires a thoroughly material investigation to identify the mechanical properties and time-dependent behaviour such that a trustworthy design optimization can be made. However, a design for a non-assembly high-speed vitreous cutter is made and with the upcoming developments in the 3D Printing techniques and materials the design might form the basis of a high-speed vitreous cutter. This research tested the most ideal case and gave further insight bringing us a step closer towards a non-assembly high-speed vitreous cutter.

Retinal detachment occurs when liquid slips behind the retina and does not allow the latter to lay flat on the posterior region of the eye. It alters the vision of the patient, hence requiring surgery to be corrected. In some cases, retinal detachment can occur after the retina has been treated for other pathologies.
Indeed, more than 20% of highly myopic patients who have been treated for retinal diseases are subject to retinal detachment a few months after the surgery and are required to undergo a second surgery. It is believed that a membrane, also called Vitreous Cortex Remnants (VCR), that arises due to vitreoschisis,
a retinal disease, is the reason for the re-detachment. VCR is often not dealt with during surgery because its removal is time-costly, the VCR is not well visible and instruments are not optimally adapted for removing VCR. The work aims to develop and experimentally evaluate new methods of removing VCR. For that purpose, a series of test prototypes were manufactured, and three surgeons assessed the efficiency of the prototypes for removing VCR from dissected pig’s eyes. Each eye was treated pre-experimentally according to a new model that tries to recreate vitreoschisis in a young porcine eye. The efficiency of each test prototype was assessed based on the force that the instrument tip exerted on
the pig’s retina, the number of strokes taken to remove the VCR completely, the tissue damage and the time used. Furthermore, the optimal tip length was determined based on the surgeons’ feedback. The results show that the force greatly depended on the stiffness of the instrument tip and that the most efficient prototype consisted of a PVA wipe cut to size 6x1x1 mm and a 0.1 mm diameter Nitinol wire. The prototype exerted a maximum force of 0.68 gr. The number of strokes was around 40, and the optimal tip length was just under 4.5 mm. While the experiments showed that it is a promising design, the tip needs to be remodeled to comply with the low stiffness needed and to be able to fit within a 23 gauge tube.

Introduction - Arthritis is a condition causing pain, deformations and loss of motion in human joints. The surgical instruments used to place a specific unconstrained prosthesis that is used to treat an arthritic joint are difficult to use. The objective for this thesis is to improve the current placement procedure by carrying out an analysis on the procedure and by developing a novel (set of) instrument(s). Analysis - Analysis displayed which instruments used during the placement procedure fall short, and in what way. The analysis forms the basis for a list of design criteria. Concept design - A concept was generated for the part of the procedure in which the bones are prepared such that the prosthesis can be placed. Final design - One of the surgical instruments that is part of the concept was designed in detail and a prototype was made. Evaluation - An evaluation study was carried out on cadaveric joints. The efficacy of the working principle of surgical instrument was demonstrated. Discussion - It is not possible to make a statistically significant comparison between the performance of the surgical instrument and the performance of the conventional instruments used for the same procedure. Conclusion - The surgical instrument could be an improvement to the current placement procedure. A comparative study between the surgical instrument and the conventional instruments should be carried out.

Laparoscopy is a type of minimally invasive surgery in which instruments with long, slender shafts between handle and end effector are inserted through small incisions in the abdominal wall. A laparoscopic aspirator-irrigator (LAI) has a hollow shaft used to evacuate undesirable substances using a vacuum pressure, rinse tissue using a stream of pressurized saline, and manipulate adherent tissue.
Although laparoscopic instruments typically have a steerable tip to compensate for the loss of maneuverability due to the small incision, all currently available laparoscopic aspirator-irrigators lack a steerable tip. This lack is associated with sub-optimal aspiration and irrigation efficacy, mechanical trauma resulting from interference with obstructive tissue, interference with other instruments, and a lack of fine motor control of the tip. Although LAI’s with a steerable tip are known from patent literature [1]–[6], they all seem to have been abandoned, which suggests that the implementation of a steerable tip on an LAI tends to compromise performance relative to cost. Therefore, the objective of the current study is to design a new laparoscopic aspirator-irrigator (FlowFlex) with a steerable tip that mitigates the limitations of a conventionally rigid, straight tip to the extent of warranting its additional cost.
To meet the objective, design requirements have been generated, tentative prototypes have been designed and evaluated, and a Final Prototype has been designed based on the superior tentative prototypes. Its steerable tip consists of an inner tube that is rigid and straight and an outer tube with an elastic, pre-curved silicone tip. Whereas the inner tube is stationary, the user can rotate, retract, or protract the outer tube by moving the tip control wheel on its proximal end using the index or middle finger, causing the tip to rotate, straighten, or deflect.
The Final Prototype meets all important design requirements; it is cost-effective, due to the particularly simple and cheap steerable tip, it has ample flow rate capacity, it is unsusceptible to clogging, and it is sufficiently maneuverable. Although its main limitation is the low stiffness of its pre-curved tip, the ability of the tip to be rigidized by straightening makes it at least as capable of manipulating tissue as a conventional laparoscopic aspirator-irrigator.

Background: In vitrectomy, a type of eye surgery, surgery instruments must pass through an incision in the sclera. The architecture of the incision is of great im-portance to the closure of the wound after the procedure and through that the risk for complications like hypotony and endophthalmitis. Current studies suggest that tri-planar incisions provide better sealing, however for a surgeon it is challenging to pro-duce the desired architecture easily and consistently. The objective of this study is to: “Design and verify a new, reliable and easy to use method to create tri-planar inci-sions for scleral cannulas to limit leakage after extraction of the cannula.”
Method: Analysis of the factors affecting the tri-planar incision method in terms of reliability and ease of use was performed, leading to a set of design requirements. Based on the requirements, different incision methods were explored and compared. The selected method was transformed into a functional prototype, which was subse-quently evaluated on consistency and leakage. The evaluation was done by insertion on silicone sheet, eye phantoms and ex-vivo porcine eyes. The tri-planar incision was compared in leakage to straight and oblique incisions, two other common type of ar-chitectures.
Results: The method performed using a designed device was able to create the de-sired tri-planar consistently. These incisions provided a better seal than a straight in-cision. However, for tri-planar compared to an oblique incision the test was inconclu-sive and further research is needed to distinguish between the two.
Conclusion: As tri-planar incisions can now consistently be made with the use of the new method, further research can be performed to link the number and type of com-plications, like hypotony and endophthalmitis, to the incision statistics.

Gripping slippery, compliant, and irregular tissues during MIS is often challenging using a conventional gripper. A force grip has to compensate for the low friction coefficient between the gripper’s jaws and tissue surface. This study focuses on the development of a suction gripper as an alternative for the well-known tissue gripper. Suction technology applies only normal forces to grip the tissue without the need to enclose it. Inspiration is taken from biological suction discs. These are able to attach to a wide variety of substrates, varying from slimy surfaces to rough rocks subjected to chaotic streams. The designed suction gripper is divided into two parts; the suction chamber inside the handle where vacuum pressure is generated, and the suction tip that makes contact with the target tissue. The suction tip fits trough a 10 mm diameter trocar, and unfolds in a larger suction surface when being retracted from the trocar. The suction tip is built in a layered manner. Each layer focuses on a specific function to allow for safe and effective tissue handling: 1) Foldability, 2) Air Tightness, and 3) Slide ability. The footprint of the tip focuses on its adaptability to different substrates. Experimental validation of the suction tip’s attachment performance on slippery and flexible phantom tissue showed a maximal attachment force of 3.27±0.15 N. The occurrence of leakage appeared to be the main reason that larger attachment forces are not reached. The proposed prototype of the suction tip provides a base for further research to develop a reliable and effective tissue gripper actuated by suction.

The conventional fabrication process of prosthetic sockets is known for being labor-intensive and time-consuming. It takes the user to wait 2-5 weeks to receive the prosthetic socket. In addition, most of the conventional sockets have fixed volumes that do not consider the volume fluctuations that the user experience daily because of muscle activities and comorbid medical conditions. 3D printing has shown promising results in producing lower limb sockets; however, upper limb sockets are overlooked. The goal of this master thesis is to design and fabricate a volume-adjustable, affordable, 3D printable transradial, prosthetic socket. In this research, the V3D (Volume-adjustable, 3D printable) socket has been developed with a material cost of only €30. The socket provides a volume-adjustable closure system around the residual limb, easiness of donning and doffing without skin shearing, full elbow extension, high range of flexion, low weight, and breathability. The socket was designed to be able to withstand a load of 50N that can be applied axially or transversely at the tip of the socket without breakage. The designed socket was 3D printed using the Fused Deposition Modeling (FDM) printing technique, from tough Polylactic Acid (tough PLA). Mechanical and human assessments have been conducted to evaluate the strength, function, and comfort of the developed socket. Results have shown that the socket managed to withstand a load up to 100N that was applied axially and transversely, respectively, without showing any signs of damage. During testing the socket with 5 participants for evaluating its comfort and function, the socket has succeeded to achieve full contact with the residual limbs, while offering volume-adjustability that accommodated the differences in size and properties of the residual limbs among participants. Not only that, but also, the socket succeeded to allow full elbow extension, a range of flexion up to 95°, and donning and doffing in less than 10 seconds without applying any shear forces on the skin. The developed V3D socket has proven the possibility to 3D print reliable sockets using the FDM printing technique with a total labor time of 4 hours per socket, and a total fabrication time of 5 days with a material cost of only €30. In addition, the socket has proved that it can be fitted using a caliper in case 3D scanners are not available. That advantage makes producing the V3D socket feasible in communities that do not have access to 3D scanners. Furthermore, the socket can be parameterized such that users with similar geometry and comparable sizes of residual limbs can fit the same socket, which would make the fabrication process less labor-intensive and less time-consuming as it was aimed for.

Background: Colonoscopy is a successful screening method to prevent colorectal cancer (CRC). Biopsies are performed from suspicious tissue spots during the colonoscopic procedure to find cancerous polyps in an early stage of the disease. However, taking multiple biopsies is rather time-consuming and requires many repetitious actions from the gastroenterologist. The current state of the art instruments either do not solve this issue or do not meet the user requirements. The goal of this study was, therefore, to design a new endoscopic instrument to store multiple biopsies during a colonoscopy. Methods: The input from different gastroenterologists, together with risk analyses, has resulted in the lists of requirements for the device. These requirements have defined the design space for the development of the instrument. The tip functionalities were subdivided into five design challenges: integrate, transport, remove, store and secure. The solutions for these challenges were combined to generate concept directions. Within these directions, concepts have been created and analysed, which resulted in the final design, 'the Biopsy Containuer'. Different prototypes have been made from this design to evaluate the functionalities of the instrument and receive the opinion of potential users. Results: The evaluation showed that the developed prototype is able to remove a biopsy from the biopsy forceps and store five biopsies without loss or change of order inside the container of the instrument. Besides, potential failure movements were investigated, and they did not result in breakage or malfunctions. The participating gastroenterologists in the user assessment were, in general, pleasantly surprised about the potential of this instrument. Performing six biopsies using the Biopsy Containuer results in a time reduction of 44 %. Discussion and conclusion: When taking the learning effect found during the user assessment analysis into account, the time to perform six biopsies is reduced by 57 %. More research is required to evaluate the influence of bowel tissue on the instrument functionalities and the most suitable handle design. The next prototype iteration can include the use of one single polytetrafluoroethylene (PTFE) tube and laser cutting to create the tip structures. The Biopsy Containuer is able to store multiple biopsies during a colonoscopy, and the potential purpose in endoscopic procedures besides colonoscopy could be useful.

Developments in minimally invasive surgery such as natural orifice transluminal endoscopic surgery and single port laparoscopic surgery have pushed medical devices to be higher articulated and more dexterous. These surgery methods have proven to greatly decrease bleeding, scar tissue, hospital time, and cost. The procedures involve the navigation of flexible instruments through tortuous anatomical pathways. To reduce chances of tissue damage it is desired to reduce the interaction with anatomical structures during the trajectory. To realize this aspect a so-called Follow-the-Leader (FTL) motion has been adapted as a design feature for medical devices. This motion allows for the shaft of the instrument to conform to the shape taken by its end-effector without relying on anatomical reaction forces. One strategy to achieve FTL motion is the so-called alternating advancement where two shafts subsequently switch from flexible to stiff in order to conserve the configuration of the shaft. These devices have been shown to possess relatively many degrees of freedom for a small number of actuators which can greatly reduce the cost of the device. A state-of-the-art analysis has shown that, despite the kinetic advantages, there are no alternating FTL devices that use pneumatically actuated shape locks to constrain the flexibility of the shaft. In this work an alternating FLT medical device with pneumatically actuated shape locks was designed, produced, and tested. The device has a diameter of 40 mm and nine degrees of freedom. The total bending angle is 90 degrees with a bending radius of 85 mm. The device leaves room for improvement but does show that two concentric shafts can be shape locked pneumatically to perform an alternating FTL motion.

Introduction: This research aims to develop a 3D-printed ergonomic handle design for a steerable laparoscopic instrument with minimised part assembly. Steerable laparoscopic instruments are used in minimally invasive surgery (MIS). MIS is a technique where surgeons insert long slender surgical instruments through small incisions of five to ten millimetres in the abdominal wall. According to various studies regarding the ergonomics of laparoscopic instruments, improvements in the control and handle design are necessary. Non-ergonomic design and control, combined with extensive surgery, can cause physical discomfort, muscle fatigue, mental stress, and other complications to the surgeon that can adversely affect the patient. Improvements in the design can overcome inconvenient and uncomfortable movements of laparoscopic instruments to make MIS safer for surgeons and patients. In addition to the improvements in ergonomics, a reduction in assembled parts in current laparoscopic instruments can shorten the assembly time, resulting in lower manufacturing costs. 3D-printing offers design freedom to enable complex structures with minimised part assembly and has the potential to customise the instrument specifically to the surgeon. Methods: The working principles and ergonomics of sixteen steerable laparoscopic instruments were analysed. Requirements were set up from the analysed laparoscopic instruments, handle design ergonomics and control ergonomics to develop an ergonomic handle design. Concepts have emerged from the requirements, and the most promising concept has been developed towards a final design. From the final proposed handle design emerged a working prototype, The LapaJoy. The 3D-printing technique of stereolithography was used to manufacture the LapaJoy. Steering, grasping, bending and locking tests were conducted to compare the retrieved data with the requirements to validate and evaluate the working principle and performance of the LapaJoy. Results: The LapaJoy consists of five assembled parts and allows the surgeon to control the four different functions of the instrument. The surgeon can control the end-effector in two degrees of freedom, lock the end-effector's position, open and close the grasping forceps, and lock the grasping forceps in place. All four functions of the LapaJoy can be performed by a novel two-finger control system using the index finger and thumb. The results show that the LapaJoy can manipulate the end-effector in two degrees of freedom by 20 degrees and lock the end-effector in any desired position. The instrument's grasper is functional, and the grasping forceps can be locked in place upon release of the grasper trigger. However, an analysation showed a reduction in the opening range of the grasping forceps with each opening and closing cycle. Furthermore, a material response wherein deformation of the steering segment's flexure occurred. The steering segment's flexure was deformed by 9.9 degrees after applying almost 1 N to the grasping forceps in the vertical direction. In addition, fatigue and failure of the grasper and joystick design occurred during extensive use and testing. Conclusion: By developing the 3D-printed ergonomic handle design with minimised part assembly, new knowledge was acquired in the possibilities of 3D-printing as a manufacturing technique for laparoscopic instruments. Future research is recommended to increase the steering angle and use more durable materials to create a more reliable product. The instrument's performance showed excellent potential in 3D printable laparoscopic instruments with minimised part assembly. The LapaJoy has the prospect of being an ergonomic, low cost, disposable MIS instrument.

Background: The goal of minimally invasive surgery (MIS) is to perform surgery by minimal damaging the body. Compared to traditional open surgery MIS results in faster recovery and lower mortality, and is therefore the preferred method for performing a biopsy. Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a type of MIS where an instrument enters the body through a natural orifice to reach the target. During NOTES an instrument enters the body through a natural orifice to reach the target. Upon entering the body via a natural orifice, first the target area needs to be reached and second, the targeted tissue needs to be transported out of the body for further examination. Currently used instruments for NOTES are suboptimal for transport through tubular organs due to damaging the tissue. In this study, a friction-based transport mechanism, inspired by eggs of parasitic wasps, was developed as an improved tool for NOTES. Additionally, the possibility to steer this instrument was examined as well. Methods: State of the art mechanisms were analysed and selected based on their potential for being used as a flexible system for locomotion through a tubular organ and tissue transport. Requirements of this instrument were determined which were divided into requirements for the flexible shaft and for the actuation of the locomotion and transport mechanism. Requirements were also determined for the additional wish for the instrument to be steerable. Based on these requirements a final design of a flexible shaft and actuation was developed. The design process for steerability of the flexible shaft is described as well, resulting in a tip that can be added to the flexible shaft to add steerability. Performance of the flexible shaft was evaluated based on locomotion through a tube, tissue transport and steerability in a simulated setting. The flexible shaft was tested if it is possible to locomote through a tube, transport tissue and can be steered. Results: The developed instrument was able to locomote in a straight direction and three different configurations: with a bending radius of 80 mm, 105 mm and 130mm and a bending angle of 45°, 30° and 15°, respectively. The locomotion rate in the straight direction was 6.17±0.27 mm/cycle and was 5.21±0.21 mm/cycle in the maximum bent direction (bending radius of 80 mm). The instrument was adequate for the intended use: (1) insertion into a tube, (2) locomote through the tube, and (3) transport tissue out of the tube using the flexible shaft. Adding the tip and attached steering wire ropes with manual operation allowed the shaft to be steered up to an angle of 90° with a bending radius of 58 mm. Discussion and conclusion: A flexible shaft instrument was developed that was able to locomote and transport tissue through a tube. Additionally, a steering tip was designed that allowed to steer the instrument from outside the body/tube. While lower locomotion rates were observed for lower bending radii, the developed design shows great potential for an instrument to perform NOTES with minimal burden for the patient.

Two major challenges in the field of agriculture are the need for increases in food production due to the ever-increasing world population and simultaneously climate change caused by global warming. The increasing world population requires more food, and the food needs to be of a higher standard. Currently, the increase and high quality food production by farming are becoming difficult due to more inconsistency of the climate. Plant breed companies use old-fashioned science in their attempts to overcome the agriculture challenges. For plant breeding, multiple plants are combined to develop a plant crop with desired characteristics that can withstand to the environmental challenges, produce high quality crops and provide the production volumes according to the required specifications. If such a crop is developed using breeding, a batch of plant seeds will be produced to sell the plant seeds all over the world. Two main problems do come from breeding and production of these newly developed crops, firstly breeders need information about the plants for efficient plant breeding, and secondly, the quality of the produced plant seeds has to be ensured. The quality of the plant seeds is an important factor to sell the produced plant seeds over the world to growers and farmers. To ensure the quality of the seeds, phenotype experts obtain the information and perform quality assessments of the seeds and grown plants. To obtain information on plants, the experts use plant phenotyping in which the characteristics of the plant are described and evaluated. The evaluation of the plant characteristics provides a quality assessment of the batch of produced plant seeds. The quality assessment is done by growing the plant seed to seedlings and compare the grown seedlings with each other. The visual comparison between the seedlings is used to give a quality label to the produced batch of seeds. At the moment this visualization and subjective comparison of seedlings is the state of the art. Experts did not believe it is possible to assess the seedlings otherwise. To move away from the subjective approach, Rijk Zwaan BV is looking into more objective measurement systems to obtain plant information. The objective plant information of the seedlings provides solutions of objectively assessing quality and inform plant breeders with extra information making the plant breeding process more efficient. In this study, the feasibility of a digital phenotyping system able to give plant information and a quality assessment of the seedlings was examined. To show the possibilities of the system a model of a digital seedling quality system was developed. By applying the literature of plant phenotyping systems, a phenotype and quality assessment data pipeline were established. The data pipeline was developed to be understandable and transparent for the experts to ensure acceptance of a digital system. The plant phenotype pipeline consists out of multiple components. Each component of the plant phenotype data pipeline has been developed to form the seedling quality system model. The developed model is called SeeQS (Seedling Quality System) and is able to seek out the quality of the seedlings and provide phenotype information of the seedlings. SeeQS was evaluated using multiple samples of pepper seedlings to show the performance and capabilities of a digital phenotyping-based quality system. The system performance shows to be very capable and accurate to assess the quality of seedlings and give plant measurements. The model shows that it is possible to assess the quality of seedlings using a digital phenotyping-based system. Due to the transparency of the developed model, the experts understand the versatility of the digital system. Now, the phenotype experts accept the possibility of a digital system to obtain plant information and give a quality assessment. Due to these positive results, the company wants to continue with the development and implementation of a digital seedling quality and phenotyping system.