A common method of diabetes treatment is monitoring of blood glucose using a continuous glucose monitor(CGM). These monitors come in different forms, but are often uncomfortable because they penetrate the skin with needles. For this project, an alternative, smaller sensor is explored for which the design process is centred. This sensor is inserted into the dermis layer of the skin, measuring interstitial fluid glucose and should be less invasive and more comfortable to the user.
The project is divided into two parts, one discussing the sensor reading circuit, and the other the digital processing of sensor information. This report is on the digital processing, and will convert sensor data into blood glucose concentration estimates. To achieve this, various mathematical models and filter techniques are implemented and evaluated. The subsequent system is subdivided into modules, each performing a task in the total process line. The report gives a general introduction to the broad topic and eventually outlines the structure and motivation behind these models.
In the end a Kalman filter and biophysical blood-interstitial fluid dynamics model are shown to improve performance over a linear model in an in silico test environment.
This work represents a step towards a working glucose sensor which can be used in CGM solutions, with the potential application in both clinical and at-home diabetes management.

Currently, the testing procedure for 3D Hall sensors at the MUSIC lab is time-consuming, labour intensive, and is susceptible to systematic errors. There is a need for an automated, accurate, and repeatable test setup for 3D magnetic sensor characterisation. That is why the objective of this thesis is to develop a control interface that allows users to define arbitrary magnetic field vectors and perform 3D magnetic field sweeps on a Hall sensor placed in a 3D Helmholtz coil. The development was performed in three stages: calibration of a 3D Helmholtz coil, development of a 3D magnetic field sweeping script, and validation of the system by benchmarking measurements from two commercially available 3D Hall sensors against known magnetic fields. The 3D Helmholtz coil was successfully calibrated, finding that the generated magnetic field strength of 2.87mT corresponds to the maximum relative uncertainty of 2%. A LabVIEW script was developed, enabling users to generate 3D static magnetic field vectors and 3D magnetic field sweeps with definable orientation, resolution and strength. Lastly, the system was validated using two commercial Hall sensors, confirming its stability and accuracy for testing other Hall sensors. This system can be used for repeatable magnetic sensor evaluation in research, with a versatility that can benefit various sensor configurations.

As novel three dimensional Hall sensors are being developed, it is important to be able to demonstrate their working principles and applications to other researchers and potential investors. One such application is seen in joysticks, which are more durable and reliable when they are made with Hall sensors compared to traditional potentiometer joysticks. In order to develop the joystick, readout mechanisms for multiple commercial Hall sensors are developed first. A joystick design configuration and permanent magnet are selected based on requirements and magnetic field simulations. The joystick is 3D printed and a demonstration screen showing the position of the stick and a moving ball is developed. The joystick has a delay of 9 ms, a maximum pitch of 61°, a resolution higher than 1° and an average error of 2.4° for the pitch and 1.59° for the rotation angle. However, this error may be due to the way the angle was physically measured, rather than errors in the measured magnetic field. Overall, the resulting joystick prototype functions more than sufficiently as a demonstrator.