In the context of prosthetic devices, the absence of natural sensory feedback poses a significant challenge, leading to limited proprioceptive sensation and reduced control over artificial limbs. This study explores the potential of establishing a magnetic connection between prosthetic devices and muscles to enhance proprioceptive feedback and facilitate more intuitive control of prosthetic limbs. The primary objective is to ascertain the safe range of forces that can be transmitted magnetically from a prosthesis to a muscle, with ethical considerations guiding the allocation of muscle resources. Preliminary experiments conducted using Silicone Ecoflex 0030, chosen for its stress behaviour similarity to natural muscle tissue, serve as the cornerstone for this research. A novel methodology is introduced to predict the forces generated when magnets snap, particularly when one magnet is embedded within an elastic medium like silicone, replicating the force distribution characteristics of muscle tissue. The theoretical model guiding these predictions is based on empirical data collected from experiments that investigate the magnetic force interactions between magnets and the distinct properties of silicone materials. Validation of the theoretical model for predicting the snapping point is achieved through a comprehensive series of final experiments. This study demonstrates that the monopole model, tailored for magnets with parallel-aligned poles, yields highly accurate predictions when compared to empirically measured data concerning magnet force modelling. Additionally, within silicone, the force-displacement relationship exhibits linearity, with stiffness primarily contingent on the length of the implanted object. Force transmission experiments involving a magnet embedded in silicone reveal that magnets snap at forces of less than 3 Newtons. A significant outcome of this research is the development of a validated methodology for predicting the force when a pair of magnet become unstable and snap. This methodology is applicable to scenarios involving magnets embedded in elastic media like silicone and holds the potential for extending predictions to snap forces in muscle tissue. The implications of this study are promising, suggesting the feasibility of employing magnets as sensors to detect muscle intent and as activators to provide feedback by mobilizing implanted magnets, thereby stimulating muscle spindles. These findings open new avenues for enhancing proprioception and control in prosthetic devices.

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.

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.

Post-mortem interval estimation (PMI) is a key part of forensic investigation. Accurately obtaining a PMI early in the investigative process improves the reconstruction of events, directs follow-up research and narrows down suspects in case of homicide. Currently, PMI is determined using Henssge’s nomogram requiring ambient temperature, rectal temperature, an estimated body weight and an estimated correcting factor to account for the clothing of the deceased. These body weight and correcting factor estimates are subjective and can lead to errors of up to 14 hours from the actual PMI. To improve the accuracy of the PMI Academic Medical Centre (AMC) in Amsterdam, TU Delft, the Dutch Forensic Institute and the Dutch police initiated the Therminus project. Using the Wilks Model [1]with specialised equipment can increase the accuracy of the PMI by up to a 15-minute margin of error under ideal circumstances and up to 3.2 hours under non-ideal circumstances. For the Wilks model, the weight of the deceased remains an important input and the QuickScale was developed as a specialised tool to provide this information to forensic investigators at the crime scene. This report contains the development of the second iteration of the QuickScale, the QuickScale 2.0. Objectives of this development were: 1. To Finish the QuickScale prototype, design the modules needed for building in the electronics and for adding user-friendly, intuitive controls. 2. To design and conduct usability studies with forensic investigators and use the obtained information to further improve the QuickScale construction, electronics and usability. Using a design analysis and usability engineering approach for the QuickScale design and user interface respectively. The QuickScale design was calibrated, and validated and possible improvements were identified. Three different user interfaces were developed and usability studies were conducted for groups of students and forensic investigators. New design requirements were derived from both the design analysis and usability studies. The resulting QuickScale 2.0 design incorporated the user interface that resulted in the least user errors. It met 27 out of the total 30 design criteria and contains: • An ambidextrous user interface. • Correcting springs for the non-linearity of the load cell when measuring weights below 20kg. • Handlebars with improved grip which can easily be extended to accommodate more users. • Safety labels with an abbreviated guide on the field use and stickers indicating the controls The un-met design criteria were an indicator of remaining battery life and the possibility that both units can display a difference in weight larger than 0.5 kgs, especially at the start of weight measurements. As this design still needs to be produced, it needs to be tested and evaluated. Special care should be taken when calibrating the QuickScale 2.0 and altering the calibrating method might be necessary. Furthermore, it is recommended to integrate the QuickScale 2.0 with other Therminus equipment in future evaluations. All in all the QuickScale 2.0 is a user-oriented step toward more accurate post-mortem interval estimation.

Background: Through technological development, a variety of mechanical finger joints have been produced. No current design takes inspiration from nature enough to develop a synovial inspired single finger joint. Due to this the potential performance is unknown, while natural joints out perform mechanical finger joints with respects to the coefficient of friction. Goal & Research question: The goal is to construct a novel 3D printed 1-DOF mechanical synovial proximal interphalangeal(PIP) joint to explore the parameters of influence. In the exploration of these parameters, the following research question is formulated: To what extend does each of the following variables effect the coefficient of friction, the joint stiffness and hysteresis of a synovial joint? In which the material selection, contact surface roughness, capsule influence and fluid selection is considered. Methods: Design requirements and performance criteria were formulated to guide the design process, from which the final design was generated. The design was measured with an optical profilometer to determine the surface quality and the performance evaluated with a custom build friction test bench. Results: Through the process of this paper, a novel 1-DOF mechanical synovial joint was designed with a range of motion of 100 degree, along with a proof of concept design with 100 degrees in flexion and 8 degree in hyperextension. The synovial joint was successfully tested to access the performance and evaluate to which extend each of the parameters stated in the research question effected the performance. Conclusion: The joint was successfully produced and allowed for evaluation of the desired parameters. Overall, the contact surface material and the contact surface roughness are the main contributors to the performance of the joint. The capsule has mixed influence while the lubrication shows some improvement with coated low roughness samples over the dry friction conditions. For all other cases the dry sliding baseline joints outperform the encapsulated lubricated joints.

Background: Scoliosis is a three-dimensional abnormal curvature of the spine, with Adolescent Idiopathic Scoliosis (AIS) being the most common type. Current fusion treatment is highly invasive and removes all mobility of the fused spinal segments. To tackle this problem, non-fusion techniques were developed, that try to correct the abnormal spinal curvature while maintaining healthy spinal mobility. The state of the art of non-fusion treatment includes techniques that have highly inefficient methods of correction, contain long and hefty structures leading to large surgical scars, or cause the need for revision surgery. Most importantly though, all of the current techniques have high complication rates. It was therefore deemed necessary to design a mechanism that facilitates minimal invasive and local, non-fusion correction in a mechanically effective way, by applying constant force in the appropriate direction. Methods: The anatomy and mechanics of a thoracic spinal segment were analyzed, showing the challenges that are at hand. From there, lists of requirements and wishes were generated that initiated the conceptualization process. Concepts were then generated, categorized, and selected after which it was shown that the concept of a single buckled leaf spring with joints was the most suitable. Future vision figures were made showing how an implant could look like that contains this mechanism. The mechanism was then further developed and an experimental setup was designed and built. This setup was used to carry out four proof of principle experiments that examined the viability of the buckled leaf spring as functional mechanism. The relation between thickness and buckling force was tested, as well as the hysteresis of the mechanism. Furthermore, the effect of misaligning the mechanism both translationally and rotationally has been examined. Finally, the mechanism was placed inside soft tissue phantoms to examine the effect of the presence of surrounding soft tissues. Results: A buckled leaf spring that fits the size and material requirements was manufactured and the results of the proof of principle experiments show that it manages to create a constant buckling force of desired magnitude for correction. However, misaligning the implant did show effects on the force profile, with the effects of translational misalignment being the most significant. Finally, little hysteresis was perceived, which significantly increased when the leaf spring was placed within a soft tissue phantom. Discussion and Conclusion: The mechanism is as of yet not suitable for clinical implementation. Further design steps must be conducted and an extensive analysis of the anatomical and mechanical effects of placing the implant against the spinous processes must be carried out. Further recommendations have been made to improve the design and functioning of the mechanism. This study has demonstrated the potential that the mechanism of a buckled leaf spring has in the constant force correction of scoliosis.

Duchenne Muscular Dystrophy (DMD) patients suffer from a severe form of progressive muscular weakness. Consequently, as the disease progresses these patients become more and more dependent on assistive devices for their daily activities. For instance lifting their arms against gravity already becomes challenging. So far, a considerable amount of effort has been put in the development of assistive devices. However, compensating the weight of the hand remains challenging as the required balancing torques are dependent on the position of the hand and the orientation of the forearm. In this research a solution is proposed to passively compensate the weight of the hand by making use of a simplified torque profile (a constant torque). The effectiveness of this profile was assessed experimentally in a group of healthy subjects. For this the wrist muscle activity required to lift the hand against gravity was measured through surface electromyography, for several types of compensation. From this experiment the conclusion can be drawn that a constant torque profile performs similar to the theoretically ideal type of balancing, showing a similar reduction in the anti-gravity muscle activity. Based on these findings, a mechanism has been developed capable of providing an adjustable constant force, by making use of a combination of positive and negative stiffness springs, for implementation in a wrist support for DMD patients.

Semi-active lower limb prostheses currently use variable damping to generate the gait cycle. This, however, only dissipates energy. Variable stiffness can store and release energy, making prostheses more efficient for walking. This study aims to design and evaluate a semi-active adjustable stiffness ankle-knee prosthesis that can change its stiffness during a single gait cycle. A Knee-ankle prosthesis that can change its stiffness from a high to low mode in a gait cycle was designed, tested and evaluated. The principle for stiffness change in this design is a leaf spring for which the force application point on the leaf spring moves. The design can move the application point quickly over a length since the rotation of the outer frame is converted into a linear motion of the application point. The stiffness, movement range, power usage and rate of stiffness change were evaluated with different tests. One test is for the stiffness and movement range, and one is for the power usage and stiffness rate of change. The ankle joint’s high and low stiffness modes were 1.4 N m/° and 0.6 N m/° respectively. The movement range for the ankle’s high and low stiffness mode was 0° - 15° and 0° - 20° respectively. The knee joint’s high and low stiffness modes were 2.4 N m/° and 0.2 N m/° respectively. The movement range for the knee’s high and low stiffness mode was 0° - 10° and 0° - 40° respectively. The stiffness is changeable from high to low mode in 0.4s, and the power usage is 9W. The prosthesis did not have a high enough stiffness for both joints. And the movement range of the low stiffness of the knee joint is too low. Nevertheless, the prosthesis has the novel ability to change the stiffness of both joints with only one motor. Furthermore, the linear movement of the force application point through a rotation has also not been done before, making the stiffness change fast. Still, more research and future designs are needed to make the prototype functional as an ankle-knee prosthesis. Nevertheless, the design is a promising first step to designing an efficient semi-active adjustable stiffness ankle-knee prosthesis.

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.

Introduction: Amputees may be eligible to use a socket or osseointegrated (OI) prosthesis after losing a limb. A lot is known about the stump-socket interface in transtibial (TT) amputees. However, there are hardly any articles that explain the load transfers between the tibia and an OI prosthesis. For this reason, this study will focus on the load pattern at the bone-implant interface. The aim is to investigate how the osseointegrated loading for TT amputees is compared to able-bodied subjects. Method: Two generic musculoskeletal models were created in OpenSim: a transtibial osseointegrated (TTO) model and an able-bodied model. The able-bodied model includes all muscles in the lower limb, where the TTO model had no muscles around the tibia. Two datasets, consisting of five able-bodied participants (healthy control (HC)) and five transtibial amputees (TTA) with a socket prosthesis, were used. The internal reaction forces and moments were analysed for the affected side during the stance phase of the gait cycle. These normalized forces and moments were expressed in bodyweight (BW) and bodyweight x height (BWH), respectively. Results: The largest forces at the bone-implant interface were measured in the longitudinal direction (-6.92 BW) for the able-bodied model, the lowest in the mediolateral direction (-0.09 BW) for the TTO model. The loading differences were the highest between the able-bodied model and the TTO model with TTA data. Around the antero-posterior axis, the largest moments were found. The able-bodied model measured 0.027 BWH, where the TTO model with HC data found 0.023 BWH and 0.017 BWH for the TTA data. Conclusion: Transtibial amputees have decreased loading at the bone-implant interface compared to able-bodied subjects. The muscles play the most prominent role in comparison with the gait pattern.

Problem: Due to high rejection rates regarding prostheses’ use, the assessment of the amputee’s use of the prosthesis has become more critical. Today’s prosthesis research is limited to assessing a users’ performance to perform tasks in a controlled environment. Therefore, these studies cannot wholly assess how the prosthesis is used in the daily lives of amputees. Purpose: The purpose of this thesis project is to create, test, and examine the performance of methods that can be used to enhance prostheses' research and evaluation. Results: We have created several enhancements and extensions regarding prosthesis research and evaluation for three sensor scenarios. In the first scenario, we only use an accelerometer, which allowed us to create a new method for creating a vector magnitude (VM) that can show us what type of arm movement is made; additionally, we created a novel scoring system to determine the intensity of movements that are performed. In our second scenario, we used an additional gyroscope, which opened up possibilities for using more advanced Sensor Fusion (SF) techniques. We created an accurate tilt estimation algorithm that remains robust against high levels of gyroscope noise, accelerometer outliers, and measurement model violations. With the gyroscope, we were also able to create a VM from rotational velocity, which displays information about the arms’ rotational movement. Additionally, we created a novel scoring system that also shows the intensity of the performed movements. Our last scenario considers the use of two Inertial Measurement Units (IMUs); we present a novel algorithm for estimating the relative sensor orientation. This algorithm uses a joint kinematic estimation method that incorporates the connection between adjacent segments within a SF algorithm that remains accurate in the vicinity of common real-world disturbances, among which are; high levels of gyroscope noise, accelerometer outliers, and Soft-Tissue-Artifacts (STA). Conclusion: The best way to enhance the analysis for prostheses research and evaluation is to start incorporating gyroscopes into the research process. This can either be in the form of the single sensor case or the double sensor system. The additional gyroscope(s) will enable the use the SF techniques and methods as discussed in this report.

Access to prosthetics is very limited to many potential users, while the need is high. There are two main reasons for this that both are related to the production of prosthetics: the lack of skilled people and high costs. Minimized assembly production using 3D printing could be a solution: no training is required, assembly takes only a short amount of time and cheap materials can be used. Besides, 3D printing is a good method for customization. Therefore, this study proposes a 3D-printed finger for a bodypowered hand prosthesis with minimized assembly. The design approach is the following. First, the human finger anatomy is studied. Then, a stylized version of the human finger is made that includes only the functions required for the prosthesis. Finally, the design principles of the stylized finger are evaluated and structurized. Based on the design principles, a finger for a prosthetic hand is designed and a prototype is developed. The prototype is produced with an Ultimaker 3 using a rigid and a flexible material in one print. The evaluation of the prototype shows promising results. The finger is suitable for a hand prosthesis that can perform an adaptive power grip and a pinch grip. The mass of the finger is 17 grams, which makes the finger comfortable to wear. An actuation force of only 16 N is required to fully bend the finger. Minimized assembly and cheap production are achieved: only four assembly steps are required and the material costs are only 1.68 euros per finger. In conclusion, the prototype shows a promising step in the direction of a hand prosthesis that is affordable, functional, body-powered, and has minimized assembly

Background: While new prosthetic hands are developed to increase functionality and allow more complex movements, prosthetic wrists are researched less. Although there are wrists available, primarily featuring 1 degree of freedom (DoF), only a few prototype 3 DoF wrists are currently known. These 3 DoF wrists usually have sufficient range of motion (RoM), but they fail in delivering high torques while being lightweight and compact, which can increase chances of rejecting the prosthesis. Objectives: The purpose of this study is to design and evaluate a conceptual 3 DoF wrist that is capable of replicating the RoM of the human wrist while keeping the size and mass as low as possible. Furthermore, the wrist needs to be able to deliver more torque than existing 3 DoF wrists. Results: A functional 3 DoF prototype was created. The design is actively controllable using three motors and pumps but can also adapt to different surroundings if the motors are off. The prototype is capable of a total range of motion of 142° for exion/extension and 90° for ulnar/radial deviation and can provide estimated torques of 4.52 Nm and 7.29 Nm respectively. Pro-/supination was not measured, but can provide a theoretical RoM of 134° and torque of 8.9 Nm. The complete wrist has a length of 150 mm and a diameter of 50 mm at the thickest part, and a mass of 166 g (including fluid). Conclusion: A 3 DoF wrist that is theoretically able to provide more torques than previously researched wrists is successfully designed and tested. The available RoM approaches the required RoM, except for pro-/supination. Future research should primarily focus on measuring the front part of the wrist using higher pressure. The 3D printed pro-/supination part of the wrist should be further researched to improve RoM and remove leakage while pressurized.

Background: Last decades myoelectric prostheses have become more usable, functional and reliable. Yet, the cost of myoelectric upper limb prostheses are still a hindering factor of widespread usage of the prostheses. In developing countries, where the demand for prostheses is relatively higher, commercial myoelectric prostheses are out of reach for the majority of amputees because of limited financial resources. Low cost myoelectric prostheses with the aim of use in developing countries are not commercially available at this moment. Objectives: The goal of this study is to develop a functional low cost myoelectric upper limb prosthesis. The developed prosthesis will be tested with standardized and validated test methods, to evaluate if the prosthesis is usable and functional. The Box and Blocks Test (BBT) and the Southampton Hand Assessment Procedure (SHAP) will be used for this purpose. Results: A low cost myoelectric prosthesis prototype was developed in this study; the MyoGrab Hand. The material cost of the prototype was 99.33 euro. The weight of the prosthesis was 352 g. The maximum pinch force of the hand prosthesis was 54.8 N. The MyoGrab Hand was tested by 20 able-bodied participants with BBT and the SHAP. In a first evaluation with ten participants, the prototype proved its functionality with an average score of 17.0 (± 2.2) with the BBT and an Index of Functionality (IoF) of average 41 (± 8.3) with the SHAP. After optimizing the Arduino code structure, the MyoGrab Hand was evaluated again. Ten able-bodied participants carried out the BBT. The average score on the BBT with the optimized MyoGrab Hand was 18.4 (± 2.4). The result of the BBT in the second evaluation was not significantly better than in the first evaluation (t = -1.3, df = 18, p = 0.21). In a durability experiment, critical failure of the prototype occurred after 16539 cycles of opening and closing of the hand. Conclusion: The goal of this study, the development of a functional low cost myoelectric prosthesis, has been achieved. The MyoGrab Hand was evaluated with standardized and validated test methods and proved itself functional. This is one of the first studies that was focused on the functionality, usability and durability of a low cost myoelectric prosthesis. The functionality of the MyoGrab Hand does not equal the functionality of commercial myoelectric prostheses, commercial myoelectric prostheses are more functional. The MyoGrab Hand was able to perform most of the activities of daily life (ADL) tasks in the SHAP, however, carrying out these ADL tasks took longer, as compared to commercial prostheses. This study is a first step in the direction of making a functional myoelectric prosthesis available to larger part of the amputee population with limited financial resources. Future research should focus on a lower weight battery solution, waterproof design and testing in a non-clinical setting.

Introduction - Grasping unknown objects is an important ability for robots in logistic environments. While humans have an excellent understanding of how to grasp objects because of their visual perception and understanding of the 3D world, robotic grasping is still a challenge. Due to the fast-growing development of deep learning methods, it is now possible to train deep neural networks on this grasp task. Objective - This thesis proposes a bin-picking pipeline that uses deep learning to take care of the perception and estimation task. The pipeline can predict grasps for known and unknown objects with a two-fingered pinch-gripper in real-world environments in a single object and multi-object scenes. Method - A grasp annotation tool has been developed to generate a wide variety of grasps in the training data that are antipodal and collision-free. Together with annotated objects, the generated grasps are used to train Grasp-RCNN. The developed Grasp-RCNN combines an object- and a grasp-detection network to predict objects masks and grasps, and a decision algorithm that picks the best-estimated grasp based on a grasp score. Results - Robotic experiments demonstrate that the proposed method allows a robot gripper to grasp both known and unknown objects in single-object and multi-object scenes with a total success-rate of 89.7% and 81.0% with average process-times of 616 ms and 739 ms per scene respectively. In a bin-picking scene a success-rate of 87.5% with a process-time of 1235 ms is achieved. Conclusion - These results indicate that the proposed Grasp-RCNN is able to grasp known and unknown objects with an accuracy that is comparable to the state-of-the-art. For production purposes, the speed of the network still can be improved.

Introduction: Prosthesis simulators are essential tools for research and rehabilitation. They can be used to increase the amount of participants in research studies or to assist in rehabilitation. The main goal of this master thesis is to design a functioning prosthesis simulator, which can be used with commonly used terminal devices. A second goal is that the design needs to be accessible for multiple research groups and rehabilitation centers. The last goal is that the design needs to solve the problems that currently exist with prosthesis simulators: sub-optimal position of terminal device and lack of restriction of degrees of freedom of intact arm. Methods: The design requirements were based on the goals and a function analysis which included the state of the art of prosthesis simulators. Based on these design requirements the final design of The Delft Pro Simulator was developed. The design method that was used was a combination of the basic design cycle and the Fishtrap model. Results: The Delft Pro Simulator is a novel 3D-printable design that is accessible for multiple users. The design consists of only 14 parts and weighs 356 grams. The design is minimal-assembly and the material cost is low. The simulator is able to constrain pro- and supination of the intact arm. It can be worn on the left or the right arm. The socket can be used with all terminal devices with the American standard bolt (1/2"-20) and the European standard bolt (M12x1.5). A user tested the functional performance of the design with two standardized tests, the Box and Blocks Test and the Nine Hole Peg Test. Discussion and conclusion: This report presents a novel prosthesis simulator design. The goals have all been achieved. The design can be used with all commonly used terminal devices. Use with a myoelectric device has not been tested, but should be possible with minor adaptations. Most parts of the simulator can be 3D-printed except for some parts which are very accessible. The design can be used with two possible orientations of the terminal device with respect to the intact hand (dorsal and palmar). The simulator is able to accurately simulate transradial limb absence by constraining pro- and supination of the intact arm, while leaving flexion and extension free.

Goal: Build and evaluate the first prototype of the Cloud Walker, a passive assistive gait orthosis. Method: The Cloud Walker uses muscles of the upper body to store energy in the springs at the back of the Cloud Walker. This energy can than be used to swing the legs forward. The Cloud Walker was evaluated by 9 healthy participants walking on a treadmill. The participants walked at different speeds with and without the Cloud Walker. Finishing speed, EMG, heart rate, stride length and questionnaires are used to obtain insight on the performance of the Cloud Walker. Results: 3 out of 9 participants finished the test at the maximum speed of 4 km/h. The muscle activity of the measured upper leg muscles was higher with the Cloud Walker than without it. The heart rate increased more when walking with the Cloud Walker than walking without the Cloud Walker. The stride length at a slower pace was larger with the Cloud Walker. The stride length was smaller at a higher pace with the Cloud Walker than without it. The questionnaires showed that the Cloud Walker is a little uncomfortable and that walking with it takes a lot of effort. Discussion: It is expected that SCI patients are able to walk in the Cloud Walker since the device is comparable to other orthotic devices such as the ARGO. The Cloud Walker can obtain a higher speed and costs less effort than comparable devices.

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.

Objective: The objective of this study was to develop and evaluate a 3D printed hydraulic actuation system, applied in a multi-articulate upper limp prosthesis. The prosthesis was designed to produce sufficient pinch force to be competitive with comparable devices (30 N), and weigh less than a human hand (<0.43 kg). The actuator should function at a high operating pressure (>1.4 MPa) and be compact, such that it fits within the mechanism of the hand. Method: The prosthesis was designed according to a modified V-model design methodology. A prototype was made that embodies the index finger, thumb, and part of the palm. The structural parts were printed using FDM. The actuators were printed in a single step using SLA, requiring only cleaning and curing. To evaluate the performance of the actuators, a set of measurements was carried out, measuring geometrical accuracy, static pressure, and friction in the cylinder. The prototype was tested on pinch force, closing time and weight. Results: Cylinders that are printed at an angle of 90 degrees with respect to the build plate, have a higher roundness that cylinders that are printed at 45 degrees. The actuators were tested at pressures of up to 4.5 MPa, showing no signs of plastic deformation, and have a theoretical maximum pressure of up to 5.9 MPa. While lifting a mass of 6.49 kg, a cylinder friction force of 25.7 N was measured, which is higher than expected. The prototype could reliably deliver a pinch force of 30 N, with a maximum measured value of 41 N. When operating at high pressures, leakage through the piston O-ring seal was not prevented. Conclusion: This study presents the first hydraulic actuation system that is fabricated entirely with 3D printing. A prototype was built to demonstrate that the prosthetic hand that is designed, is able to produce a pinch force of >40 N, showing that it can compete with similar devices. Its mass (0.35 kg without pump and battery) is less than that of a human hand. Controlling friction and leakage remains a serious concern due to the geometrical accuracy of 3D printing. Future possibilities are increased customization and reduced fabrication cost of hydraulically actuated mechanical systems.

This thesis contains the design process of a compliant shape adaptive chicory gripper for robotic sorting processes. The robotic sorting line consists of an input and output conveyor-belt. The input line contains unsorted chicories which are scanned by a robotic vision system. Overhead FlexPicker robots, equipped with chicory grippers, sort the chicories size by size onto the output line. The output line can contain a transportation crate or flowpack in which the chicories will be packed and shipped after sorting. Chicories are vulnerable for internal and external damages when touching the outer skin which makes robotic sorting difficult. The acceleration forces performed by the robot requires a strong but gentle grip on the chicory without any damaging marks. By designing a specific compliant shape adaptive gripper, sorting can be done faster, cheaper and more accurate than manual sorting. Current patents, academic literature or business applications had no solution for this chicory gripping problem. The design process for a suitable gripper started with an analysis of current patents and literature within compliant gripping in general. This provided insights in the the possibilities of compliant gripping. Based on the design requirements for the robot sorting setup, several concepts are obtained and selected. The concepts have been translated into four working gripper prototype layouts which are evaluated on force and damage requirements. Based on the results of these experiments, a first iteration prototype was made. Three additional optimizing iterations were needed to result in a prototype which reached the damage and force requirements. Further evaluation of this prototype proved a sufficient performance on robustness, endurance, operational speed and food grade requirements. The iteration 4 prototype reached therefore 17 of the total 19 gripper design requirements. To be able to accomplish the two remaining requirements, several recommendations are provided for a final gripper end product which is ready for industrial application.