Agile and Bright Intracardiac Catheters

Intracardiac imaging catheters represent unique instruments to diagnose and treat a diseased heart. While there are imminent advances in medical innovation, many of the commercially available imaging catheters are outdated. Some of them have been designed more than 20 years and therefore they lack novel sensor technology, multi-functionality, and often require manual assembly process. Introduction chapter of this thesis discusses clinical needs and introduces new technological concepts that are needed to progress the functionality and clinical value of the intracardiac catheters along with efficient and simple designs to make the catheters affordable for the patients. The following chapters are grouped into two parts that explore complementary transducer technology and a novel optical fiber-link solution for catheter-based intracardiac imaging. _Part I_ focuses on developing a new intracardiac catheter that has an advanced functionality, which provides clinician with high penetration or close-up high resolution ultrasound imaging in a single device. This agile ultrasound visualization is enabled by a capacitive-micromachined ultrasound transducer (CMUT), operated in collapse-mode, of which the operating frequency can be tuned. Acoustic performance of a fabricated CMUT is modelled and measured. Imaging performance of the CMUT array is quantified on a tissue-mimicking phantom and demonstrated both ex vivo and in vivo experiments. It is found that the combination of the forward-looking design, frequency-tuning and agile deflectability of the catheter allow for visualizing intracardiac structures of various sizes at different distances relative to the catheter tip, providing both wide overviews and detailed close-ups. _Part II_ is devoted to a novel optical technology for transmitting signals and transferring power inside catheters. A novel concept of an all-optical fiber link is introduced. A key insight obtained is that a blue light-emitting diode (LED) may be used as a photo-voltaic converter. Used in reverse under illumination with violet light, it converts significant amount of photonic energy to electricity and at the same time it may emit blue light back, which makes it a unique miniature power and communication channel for catheters. A pressure-sensing catheter prototype is built to demonstrate the concept of transmitting signals and delivering power using a single optical fiber and an LED. The potential of the power and signal fiber link solution is exploited further for ultrasound imaging. A bench-top demonstrator scalable to catheter dimensions is built, in which electrical wires for ultrasound-sensor signal and power tra

Electrifying catheters with light

Smart minimally invasive devices face a connectivity challenge. An example is found in intracardiac echocardiography where the signal transmission and supply of power at the distal end require many thin and fragile wires in order to keep the catheter slim and flexible. We have built a fully functional bench-top prototype to demonstrate that electrical wires may be replaced by optical fibers. The prototype is immediately scalable to catheter dimensions. The absence of conductors will provide intrinsic galvanic isolation as well as radio frequency (RF) and magnetic resonance imaging (MRI) compatibility. Using optical fibers, we show signal transfer of synthetic aperture ultrasound images as well as photo-voltaic conversion to supply all electronics. The simple design utilizes only off the shelf components and holds a promise of cost effectiveness which may be pivotal for translation of these advanced devices into the clinic

Le dispositif anti-abus de l'article 155 A du CGI au coeur de l'actualité

Note sous CAA Paris, 2ème ch., 28 avril 2010, n° 08PA00415. Joueur professionnel de tennis ; fiscalité internationale ; commissions versées à une société implantée à l'étranger ; assujettissement à l'impôt sur le revenu en France

Measurable error compensation with GPC in a heat-exchanger with a traffic delay

This paper demonstrates use of Model Predictive Control (MPC) to system control with delay. Generalized Predictive Control (GPC) method was selected to demonstrate the ability to both control the system and compensate the measurable disturbance while bot the system and the disturbance are delayed. For the realization the MATLAB/SIMULINK program environment was used with system parameters based on the laboratory system. GPC method was chosen and its ability to compensate the outer disturbance with delay was verified by simulation of system control based on real laboratory model. Control algorithm and simulation were realized in MATLAB/SIMULINK program environment. Results have proven capabilities of GPC method to control and compensate error in stable, oscillatory and non-minimum phase systems with traffic delay. Additionally, real model parameters were selected to test a possibility of realization. © Springer International Publishing Switzerland 201

Some recent results on direct delay-dependent stability analysis: Review and open problems

This contribution focuses an overview of selected results on time-delay systems stability analysis in the delay space, recently published in outstanding high-impacted journals and top conferences and meetings. A numerical gridding algorithm solving this problem designed by the first author is included as well. The theoretical background and a concise literature overview are followed by the list of practical and software applications. Unsolved tasks and open problems stemming from the analysis of presented methods and results concisely conclude the paper. The reader is supposed to use this survey to follow some of the presented techniques in his/her own research or engineering practice. © 2019, Springer International Publishing AG, part of Springer Nature.MSMT-7778/2014; LO130