Force Sensing in Robotic Surgery: A force sensing strategy for 3 mm shaft actuated tip articulated instruments in RAMIS

Over the past decades Minimally Invasive Surgery (MIS) has become a standard in abdominal surgery. Due to limited dexterity and bad ergonomics the field of MIS is shifting towards Robot-Assisted MIS (RAMIS). Simultaneously, the field is using increasingly small and steerable instruments to reduce invasiveness. Surgeon now work with fragile...

Microvibration test bench for tiny reaction wheels

Reaction wheels are often the main contributor to microvibrations on satellites. These vibrations are a source of pointing errors and therefore need to be limited as much as possible. The miniaturization trend in the space industry and universities fostered the production of very small reaction wheels, suited to Cubesat and PocketQube scales. A...

A Low-speed, Low-acceleration Controller for Cost-effective Reaction-wheels: Design, Simulation & Implementation

With the requirements for CubeSats increasing, a push towards utilizing high­performance equipment has never been greater. Incorporating these equipment in an environment that is cost­, space­ and power­constrained, is challenging. Simultaneously, high­performance equipment require high pointing­accuracy and low­jitter. This thesis proposes the...

CMOS Wide-Bandwidth Magnetic Sensors for Contactless Current Measurements

This Ph.D. dissertation describes the theory and realization of wide-bandwidth magnetic sensors for current measurements which breach the conventional offset and noise constraints in CMOS processes. These are achieved by several circuit-level and system-level innovations, including the use of three orthogonal ripple reduction loops (RRLs) in...

Ride comfort optimization of a ropeless elevator

Tall buildings lose a big part of their expensive space to elevator shafts. A ropeless elevator reduces the amount of shafts, because multiple cabins are able to move in the same shaft. Currently an elevator using a row of linear motors along the shaft is in the end phase of development. Tests on a full scale prototype 5 have proven the concept....

Multipath Wide-Bandwidth CMOS Magnetic Sensors

This paper proposes a multipath multisensor architecture for CMOS magnetic sensors, which effectively extends their bandwidth without compromising either their offset or resolution. Two designs utilizing the proposed architecture were fabricated in a 0.18-μm standard CMOS process. In the first, the combination of spinning-current Hall sensors...

A Hybrid Multi-Path CMOS Magnetic Sensor with 76 ppm/°C Sensitivity Drift and Discrete-Time Ripple Reduction Loops

This paper presents a temperature-insensitive magnetic sensor system for contactless current measurements. To simultaneously achieve wide bandwidth and low noise, the proposed system employs a multi-path structure with a set of spinning current Hall sensors in its low-frequency path and a set of pick-up coils in its high-frequency path. The...

Magnetic based micro-indentation catheter for soft tissue characterization in minimally invasive surgery

During the last ten years, open heart surgery has increasingly been replaced by minimally invasive surgery (MIS), which has three main advantages. There is reduced blood loss, small scars to reduce infections, and a shorter recovery time. However, MIS still lacks full surgical capabilities such as tool dexterity, tool-tissue contact force...

A Continuous-Time Ripple Reduction Technique for Spinning-Current Hall sensors

This paper presents a new ripple-reduction technique for spinning-current Hall sensors, which obviates the need for lowpass filtering to suppress the ripple caused by up-modulated sensor offset. A continuous-time ripple-free output is achieved by the use of three ripple reduction loops (RRLs), which continuously sense the offset ripple and then...