Phlebotomy - the drawing of blood - is essential for medical diagnostics, but there are problems with inconsistent sample quality, complications and high operational costs. Automation of the phlebotomy process may solve these problems; however not all steps of the phlebotomy process are currently automated. Automatic vein detection and needle puncturing have already been developed, but the tourniquet, a device used to cease the flow of blood, still needs to be automated. This study aims to design and evaluate an automated tourniquet for a fully-automated venipuncture device. In this study, two concepts were explored. The elastic tourniquet uses a strap tightened by an electric motor. The pneumatic tourniquet uses an air filled bladder, which is inflated to a standardized pressure. Both prototypes were realised and verified according to the system requirements. After verification a validation was conducted with seventeen participants, to determine usability and test user requirements. The participants used both prototypes and scored them on ease of use, comfort and sense of safety. Both prototypes did not meet three out of nineteen requirements during verification, but the shortcomings were deemed only minor. Both prototypes were considered easy to use, reasonably comfortable and instilled subjects with a high sense of safety. The pneumatic prototype scored slightly higher on comfort and safety. Users were able to apply the elastic tourniquet significantly faster and less mechanical noise was produced during operation. This study shows that it may be possible to implement automated tourniquets in fully-automated venipuncture devices in the near future. I conclude that the elastic prototype is best suited for automated phlebotomy. The shortcomings can be solved with little difficulty, whilst the design is less complex and more scalable. For this, I recommend performing clinical device testing to validate the performance of this novel tourniquet concept.

Piezoelectric vibration energy harvesting can provide a sustainable source of
energy for low-power sensors. The vibrational energy is converted to electrical energy by piezoceramic cantilevers. Replacing batteries by vibrational energy harvesters, reduces the footprint of the device and no continuous replacement of batteries is required cutting down the maintenance costs. However, the greatest issue preventing these system from being widely used is their poor reliability. The main failure mechanisms identified are ageing, temperature degradation, humidity degradation and most of all mechanical degradation. In the aim to maximise the power output, the piezoceramic cantilevers are resonating at
the eigenfrequency close to the point of the fracture strength. It is found that too large tensional deformations result in fractures in the active piezoceramic material. Experiments show that fractures significantly drops the power output and reduces the eigenfrequency. Literature suggest that tapered piezoceramic cantilevers are a reliable replacement for the conventional rectangular piezoceramic cantilevers. Experiments confirm the severity of fractures in the piezoceramic cantilevers reduction of power output as low as 75% have been measured. Tapered cantilevers show to have a higher electrical power output per unit area compared to rectangular cantilevers. Therefor less deformation is needed to achieve the same electrical output. It can be concluded that tapered cantilevers increase the reliability of the vibrational energy harvester.

The majority of cardiovascular clinical events, which are the main causes of mortality and morbidity worldwide, are caused by atherosclerotic plaque rupture. This biomechanical event occurs when the local plaque stresses exceed its strength. The plaque stresses can be assessed by computational models to predict these events. Current approaches to obtaining the plaque material stiffness properties that these models require as input have large computational costs and are therefore far from being implemented for clinical use. This study aims to develop, validate, and apply for the first time, an approach to obtaining the material stiffness properties of atherosclerotic plaque tissue much faster by employing the virtual fields method (VFM). With this method, the virtual work principle is employed with boundary problem specific, kinematically admissible virtual fields to solve energy balance equations for the material stiffness parameters that are of interest. In this study a method is presented for obtaining the virtual fields for the specific application of intraluminally pressurised atherosclerotic plaque tissue. For the purpose of validation, full field displacement maps were computed at 100 mmHg using Finite Element (FE) models based on histological slides of atherosclerotic plaque tissue. To mimic a realistic situation, the resolution and noise levels of a clinical and high frequency ultrasound scanner were used. Although higher resolution deformation maps with smaller noise levels were shown to provide more accurate results, the VFM-based technique demonstrated good performance for both the high frequency and clinical ultrasound scanner settings tested. VFM was also used in a single case study to estimate the c₁ material parameter for a Neo-Hookean incompressible material model in the case of an atherosclerotic human coronary artery. The estimated c₁-values for this case were: 21.5 kPa for diseased intima, 13.3 kPa for lipid, and 23.6 kPa for wall tissue. These values were in good agreement with the reported values from literature. In this study, VFM was applied successfully for the material characterization of atherosclerotic plaques for the first time. It is more attractive than current approaches as it is computationally less expensive and has a great potential to be extended for material characterization of even more plaque components than employed in the current study.

At this moment there are more than 150 different designs of CMMA in existence. To aid the designer to develop a new or improved CMMA or choose what the design to use, a classification system is developed during the literature research. It is based on the geometrical advantage (GA) of the CMMA, and on the input and output port motion paths. Their properties resulted in 5 different classes, with a total of 50+ CMMA designs.
The mechanical efficientcy (ME) of CMMA or compliant mechanisms in general can be non- optimal because of the elastic energy storage during motion. A technique called static balancing, can be applied to improve the efficiency of the device.
A new way to apply the static balancing, without manual preloading, is developed for a straight-line micro mechanism. This technique allows applying static balancing on batch scale that was not available before. A MEMS design is developed and a prototype fabricated and tested. Another step closer in creating statically balanced for compliant mechanical micro motion amplifiers.