Implementation of zonal control algorithms in adaptive optical systems with sparse control matrices

Miralls deformables més i més grans, amb cada cop més actuadors estan sent utilitzats actualment en aplicacions d'òptica adaptativa. El control dels miralls amb centenars d'actuadors és un tema de gran interès, ja que les tècniques de control clàssiques basades en la seudoinversa de la matriu de control del sistema es tornen massa lentes quan es tracta de matrius de dimensions tan grans. En aquesta tesi doctoral es proposa un mètode per l'acceleració i la paral.lelitzacó dels algoritmes de control d'aquests miralls, a través de l'aplicació d'una tècnica de control basada en la reducció a zero del components més petits de la matriu de control (sparsification), seguida de l'optimització de l'ordenació dels accionadors de comandament atenent d'acord a la forma de la matriu, i finalment de la seva posterior divisió en petits blocs tridiagonals. Aquests blocs són molt més petits i més fàcils de fer servir en els càlculs, el que permet velocitats de càlcul molt superiors per l'eliminació dels components nuls en la matriu de control. A més, aquest enfocament permet la paral.lelització del càlcul, donant una com0onent de velocitat addicional al sistema. Fins i tot sense paral. lelització, s'ha obtingut un augment de gairebé un 40% de la velocitat de convergència dels miralls amb només 37 actuadors, mitjançant la tècnica proposada. Per validar això, s'ha implementat un muntatge experimental nou complet , que inclou un modulador de fase programable per a la generació de turbulència mitjançant pantalles de fase, i s'ha desenvolupat un model complert del bucle de control per investigar el rendiment de l'algorisme proposat. Els resultats, tant en la simulació com experimentalment, mostren l'equivalència total en els valors de desviació després de la compensació dels diferents tipus d'aberracions per als diferents algoritmes utilitzats, encara que el mètode proposat aquí permet una càrrega computacional molt menor. El procediment s'espera que sigui molt exitós quan s'aplica a miralls molt grans.

Type II and IIIA thumb hypoplasia reconstruction.

Thumb hypoplasia treatment requires considering every component of the maldevelopment. Types II and IIIA hypoplasia share common features such as first web space narrowing, hypoplasia or absence of thenar muscles and metacarpophalangeal joint instability. Many surgical techniques to correct the malformation have been described. We report our surgical strategy that includes modifications of the usual technique that we found useful in reducing morbidity while optimizing the results. A diamond-shape kite flap was used to widen the first web space. Its design allowed primary closure of the donor site using a Dufourmentel flap. The ring finger flexor digitorum superficialis was transferred for opposition transfer, and the same tendon was used to stabilize the metacarpophalangeal joint on its ulnar and/or radial side depending on a uniplanar or more global instability. An omega-shaped K-wire was placed between the first and second metacarpals to maintain a wide opening of the first web space without stressing the reconstructed ulnar collateral ligament of the MCP joint. We report a clinical series of 15 patients (18 thumbs) who had this reconstructive program.

Prevention of Caval Collapse During Venous Drainage for CPB.

A new plastic self-expanding Smartcanula (Smartcanula LLC, Lausanne, Switzerland) is designed for central insertion and prevention of caval collapse. The objective of our work is to assess the influence of the new design on atrial chatter. Caval collapse over the entire caval axis, right atrial, hepatic, renal vein, and iliac vein is realized in drainage tubes with holes at 5 cm distance intervals. Smartcanulas with various lengths (26 cm [= right atrial], 34 cm [= hepatic], 43 cm [= renal], and 53 cm [= iliac]) versus two-stage cannulas are compared. Pressure drop (ΔP) is measured using Millar pressure-transducers. Flow rate (Q) is measured using an ultrasonic flow meter. Cannula resistance is defined as the ΔP/Q ratio. Data display and recording are controlled using LabView virtual instruments. At an 88 cm height differential, Q values are 8.69 and 6.8 l/min, and ΔP/Q ratios are 0.63 and 1.28 for the 26-cm Smartcanula and the reference cannula, respectively. The 34-cm Smartcanula showed 8.89 l/min and 0.6 ΔP/Q ratio vs. 7.59 l/min and 0.9 for the control cannula (P < 0.05). The 43-cm and 53-cm Smartcanulas showed Q values of 9.04 and 8.81 l/min, respectively, and ΔP/Q2 ratio of 0.6. The Smartcanula outperforms the two-stage cannula, and direct cannula insertion without guide wire is effective.

The Smartcanula: a new tool for remote access perfusion in limited access cardiac surgery.

Devices for venous cannulation have seen significant progress over time: the original, rigid steel cannulas have evolved toward flexible plastic cannulas with wire support that prevents kinking, very thin walled wire wound cannulas allowing for percutaneous application, and all sorts of combinations. In contrast to all these rectilinear venous cannula designs, which present the same cross-sectional area over their entire intravascular path, the smartcanula concept of "collapsed insertion and expansion in situ" is the logical next step for venous access. Automatically adjusting cross-sectional area up to a pre-determined diameter or the vessel lumen provides optimal flow and ease of use for both, insertion and removal. Smartcanula performance was assessed in a small series of patients (76 +/- 17 kg) undergoing redo procedures. The calculated target pump flow (2.4 L/min/m2) was 4.42 +/- 61 L/ min. Mean pump flow achieved during cardiopulmonary bypass was 4.84 +/- 87 L/min or 110% of the target. Reduced atrial chatter, kink resistance in situ, and improved blood drainage despite smaller access orifice size, are the most striking advantages of this new device. The benefits of smart cannulation are obvious in remote cannulation for limited access cardiac surgery, but there are many other cannula applications where space is an issue, and that is where smart cannulation is most effective.

Antibiotic cement nail for the treatment of posttraumatic intramedullary infections of the tibia: Midterm results in 10 cases.

INTRODUCTION: This is a single, level 1 trauma centre, prospective consecutive patient series with intramedullary infection in the presence of unstable tibial fracture treated using the Kirschner wire-reinforced, antibiotic cement nail. PATIENTS AND METHODS: A total of 10 consecutive patients (eight males and two females) with a mean age of 42 years (range, 20-59) suffering from infection after intramedullary nailing for tibial fracture, admitted during a period of 4 years, were included. An antibiotic cement-coated nail, handmade at the time of surgery, was implanted in all patients. This was followed by a standardised 6-week treatment protocol, extraction of the nail and definitive fixation. RESULTS: At 6 years of follow-up, infection eradication and bony union were possible in all of the patients. No further infection treatment was necessary; however, all of our patients underwent additional procedures (mean: four additional procedures per patient) for cosmetic or other non-infectious reasons (bone grafting, muscle flaps, etc.). CONCLUSIONS: The antibiotic cement-coated nail seems to be an effective treatment for intramedullary infections of the fractured tibia.

La construcción del espacio dramático en la ficción televisiva norteamericana. Análisis del espacio vivencial en las series dramáticas de la HBO

El presente trabajo analiza la construcción del espacio vivencial en cinco series televisivas producidas por la cadena norteamericana HBO: Carnivàle, Deadwood, The Sopranos, The Wire y Treme. La investigación parte de la convicción de una posible reelaboración de la historia del espacio doméstico norteamericano a través de la puesta en escena y de la potencialidad simbólica del espacio serial. De este modo, el trabajo propone un recorrido hermenéutico en el que se analiza la evolución del espacio narrativo, su evolución morfológica en dependencia de las necesidades diegéticas de cada una de las obras analizadas.

Myostatin augments muscle-specific ring finger protein-1 expression through an NF-kB independent mechanism in SMAD3 null muscle.

Smad (Sma and Mad-related protein) 2/3 are downstream signaling molecules for TGF-β and myostatin (Mstn). Recently, Mstn was shown to induce reactive oxygen species (ROS) in skeletal muscle via canonical Smad3, nuclear factor-κB, and TNF-α pathway. However, mice lacking Smad3 display skeletal muscle atrophy due to increased Mstn levels. Hence, our aims were first to investigate whether Mstn induced muscle atrophy in Smad3(-/-) mice by increasing ROS and second to delineate Smad3-independent signaling mechanism for Mstn-induced ROS. Herein we show that Smad3(-/-) mice have increased ROS levels in skeletal muscle, and inactivation of Mstn in these mice partially ablates the oxidative stress. Furthermore, ROS induction by Mstn in Smad3(-/-) muscle was not via nuclear factor-κB (p65) signaling but due to activated p38, ERK MAPK signaling and enhanced IL-6 levels. Consequently, TNF-α, nicotinamide adenine dinucleotide phosphate oxidase, and xanthine oxidase levels were up-regulated, which led to an increase in ROS production in Smad3(-/-) skeletal muscle. The exaggerated ROS in the Smad3(-/-) muscle potentiated binding of C/EBP homology protein transcription factor to MuRF1 promoter, resulting in enhanced MuRF1 levels leading to muscle atrophy.

Development of Implantable Flow-Through Left Ventricular Pressure Telemetric Transmitter for small Rodent Animals

Objective: Although 24-hour arterial blood pressure can be monitored in a free-moving animal using pressure telemetric transmitter mostly from Data Science International (DSI), accurate monitoring of 24-hour mouse left ventricular pressure (LVP) is not available because of its insufficient frequency response to a high frequency signal such as the maximum derivative of mouse LVP (LVdP/dtmax and LVdP/dtmin). The aim of the study was to develop a tiny implantable flow-through LVP telemetric transmitter for small rodent animals, which can be potentially adapted for human 24 hour BP and LVP accurate monitoring. Design and Method: The mouse LVP telemetric transmitter (Diameter: _12 mm, _0.4 g) was assembled by a pressure sensor, a passive RF telemetry chip, and to a 1.2F Polyurethane (PU) catheter tip. The device was developed in two configurations and compared with existing DSI system: (a) prototype-I: a new flow-through pressure sensor with wire link and (b) prototype-II: prototype-I plus a telemetry chip and its receiver. All the devices were applied in C57BL/6J mice. Data are mean_SEM. Results: A high frequency response (>100 Hz) PU heparin saline-filled catheter was inserted into mouse left ventricle via right carotid artery and implanted, LV systolic pressure (LVSP), LVdP/dtmax, and LVdP/dtmin were recorded on day2, 3, 4, 5, and 7 in conscious mice. The hemodynamic values were consistent and comparable (139_4 mmHg, 16634_319, - 12283_184 mmHg/s, n¼5) to one recorded by a validated Pebax03 catheter (138_2mmHg, 16045_443 and -12112_357 mmHg/s, n¼9). Similar LV hemodynamic values were obtained with Prototype-I. The same LVP waveforms were synchronically recorded by Notocord wire and Senimed wireless software through prototype-II in anesthetized mice. Conclusion: An implantable flow-through LVP transmitter (prototype-I) is generated for LVP accurate assessment in conscious mice. The prototype-II needs a further improvement on data transmission bandwidth and signal coupling distance to its receiver for accurate monitoring of LVP in a freemoving mouse.

Self-paced Movement Intention Detection from Human Brain Signals: Invasive and Non-invasive EEG

Neural signatures of humans' movement intention can be exploited by future neuroprosthesis. We propose a method for detecting self-paced upper limb movement intention from brain signals acquired with both invasive and noninvasive methods. In the first study with scalp electroencephalograph (EEG) signals from healthy controls, we report single trial detection of movement intention using movement related potentials (MRPs) in a frequency range between 0.1 to 1 Hz. Movement intention can be detected above chance level (p<0.05) on average 460 ms before the movement onset with low detection rate during the on-movement intention period. Using intracranial EEG (iEEG) from one epileptic subject, we detect movement intention as early as 1500 ms before movement onset with accuracy above 90% using electrodes implanted in the bilateral supplementary motor area (SMA). The coherent results obtained with non-invasive and invasive method and its generalization capabilities across different days of recording, strengthened the theory that self-paced movement intention can be detected before movement initiation for the advancement in robot-assisted neurorehabilitation.

Artificial Urinary Sphincter based on smart materials

Objective: There are only a few established artificial urinary sphincters for treatment of incontinence. We have developed a new device composed by three parts: the actuator, three contractile rings and a control unit. The actuator is made of Nitinol fibers, driven by microprocessor. The fibers are linked to the rings placed around the urethra. They function with alternance in their open and closed position. This concept is called piano concept. With this set-up, the constant compression on the urethra is strongly reduced. Methods: Six male sheep have been used for this study. The sphincter was open each hour for a period of 10 min., to guaranty urination. The bladder was filled with water while one cuff was closed and bladder pressure was monitored. The animals were sacrificed. Two biopsies around two cuffs of each explant and all three cuffs from each explant including urethra were analyzed. Urethra not surrounded by a cuff was taken as control. Results: The pressure exerted by the sphincter around the urethra provided continence. Simulated incontinence occurred at a pressure of 1bar measured on the bladder wall using a pressure probe. The closing force of the cuff was approx. 0·7N. No difference in tissue structure and organization of the urethra with and without artificial sphincter was observed. Conclusions: This device has several advantages compared to other urinary sphincters. It is easy to implant, has no hydraulic nature and reduces ischemic injury of the urethra by the alternance of urethral part compressed. Proof of concept in vivo has been demonstrated. Other studies are planned to determine long-term outcome.

Reliable tidal volume estimates at the airway opening with an infant monitor during high-frequency oscillatory ventilation.

OBJECTIVE: To assess the suitability of a hot-wire anemometer infant monitoring system (Florian, Acutronic Medical Systems AG, Hirzel, Switzerland) for measuring flow and tidal volume (Vt) proximal to the endotracheal tube during high-frequency oscillatory ventilation. DESIGN: In vitro model study. SETTING: Respiratory research laboratory. SUBJECT: In vitro lung model simulating moderate to severe respiratory distress. INTERVENTION: The lung model was ventilated with a SensorMedics 3100A ventilator. Vt was recorded from the monitor display (Vt-disp) and compared with the gold standard (Vt-adiab), which was calculated using the adiabatic gas equation from pressure changes inside the model. MEASUREMENTS AND MAIN RESULTS: A range of Vt (1-10 mL), frequencies (5-15 Hz), pressure amplitudes (10-90 cm H2O), inspiratory times (30% to 50%), and Fio2 (0.21-1.0) was used. Accuracy was determined by using modified Bland-Altman plots (95% limits of agreement). An exponential decrease in Vt was observed with increasing oscillatory frequency. Mean DeltaVt-disp was 0.6 mL (limits of agreement, -1.0 to 2.1) with a linear frequency dependence. Mean DeltaVt-disp was -0.2 mL (limits of agreement, -0.5 to 0.1) with increasing pressure amplitude and -0.2 mL (limits of agreement, -0.3 to -0.1) with increasing inspiratory time. Humidity and heating did not affect error, whereas increasing Fio2 from 0.21 to 1.0 increased mean error by 6.3% (+/-2.5%). CONCLUSIONS: The Florian infant hot-wire flowmeter and monitoring system provides reliable measurements of Vt at the airway opening during high-frequency oscillatory ventilation when employed at frequencies of 8-13 Hz. The bedside application could improve monitoring of patients receiving high-frequency oscillatory ventilation, favor a better understanding of the physiologic consequences of different high-frequency oscillatory ventilation strategies, and therefore optimize treatment.

Visuo-motor pathways in humans revealed by event-related fMRI.

Whether different brain networks are involved in generating unimanual responses to a simple visual stimulus presented in the ipsilateral versus contralateral hemifield remains a controversial issue. Visuo-motor routing was investigated with event-related functional magnetic resonance imaging (fMRI) using the Poffenberger reaction time task. A 2 hemifield x 2 response hand design generated the "crossed" and "uncrossed" conditions, describing the spatial relation between these factors. Both conditions, with responses executed by the left or right hand, showed a similar spatial pattern of activated areas, including striate and extrastriate areas bilaterally, SMA, and M1 contralateral to the responding hand. These results demonstrated that visual information is processed bilaterally in striate and extrastriate visual areas, even in the "uncrossed" condition. Additional analyses based on sorting data according to subjects' reaction times revealed differential crossed versus uncrossed activity only for the slowest trials, with response strength in infero-temporal cortices significantly correlating with crossed-uncrossed differences (CUD) in reaction times. Collectively, the data favor a parallel, distributed model of brain activation. The presence of interhemispheric interactions and its consequent bilateral activity is not determined by the crossed anatomic projections of the primary visual and motor pathways. Distinct visuo-motor networks need not be engaged to mediate behavioral responses for the crossed visual field/response hand condition. While anatomical connectivity heavily influences the spatial pattern of activated visuo-motor pathways, behavioral and functional parameters appear to also affect the strength and dynamics of responses within these pathways.

Atrial assist device, a new alternative to lifelong anticoagulation?

OBJECTIVE: Atrial fibrillation is a very common heart arrhythmia, associated with a five-fold increase in the risk of embolic strokes. Treatment strategies encompass palliative drugs or surgical procedures all of which can restore sinus rhythm. Unfortunately, atria often fail to recover their mechanical function and patients therefore require lifelong anticoagulation therapy. A motorless volume displacing device (Atripump) based on artificial muscle technology, positioned on the external surface of atrium could avoid the need of oral anticoagulation and its haemorrhagic complications. An animal study was conducted in order to assess the haemodynamic effects that such a pump could provide. METHODS: Atripump is a dome-shape siliconecoated nitinol actuator sewn on the external surface of the atrium. It is driven by a pacemaker-like control unit. Five non-anticoagulated sheep were selected for this experiment. The right atrium was surgically exposed, the device sutured and connected. Haemodynamic parameters and intracardiac ultrasound (ICUS) data were recorded in each animal and under three conditions; baseline; atrial fibrillation (AF); atripump assisted AF (aaAF). RESULTS: In two animals, after 20 min of AF, small thrombi appeared in the right atrial appendix and were washed out once the pump was turned on. Assistance also enhanced atrial ejection fraction. 31% baseline; 5% during AF; 20% under aaAF. Right atrial systolic surfaces (cm2) were; 5.2 +/- 0.3 baseline; 6.2 +/- 0.1 AF; 5.4 +/- 0.3 aaAF. CONCLUSION: This compact and reliable pump seems to restore the atrial "kick" and prevents embolic events. It could avoid long-term anticoagulation therapy and open new hopes in the care of end-stage heart failure.

Neonatal steroids induce a down-regulation of tenascin-C and elastin and cause a deceleration of the first phase and an acceleration of the second phase of lung alveolarization.

Pre- and postnatal corticosteroids are often used in perinatal medicine to improve pulmonary function in preterm infants. To mimic this clinical situation, newborn rats were treated systemically with dexamethasone (Dex), 0.1-0.01 mg/kg/day on days P1-P4. We hypothesized that postnatal Dex may have an impact on alveolarization by interfering with extracellular matrix proteins and cellular differentiation. Morphological alterations were observed on 3D images obtained by high-resolution synchrotron radiation X-ray tomographic microscopy. Alveolarization was quantified stereologically by estimating the formation of new septa between days P4 and P60. The parenchymal expression of tenascin-C (TNC), smooth muscle actin (SMA), and elastin was measured by immunofluorescence and gene expression for TNC by qRT-PCR. After Dex treatment, the first phase of alveolarization was significantly delayed between days P6 and P10, whereas the second phase was accelerated. Elastin and SMA expressions were delayed by Dex treatment, whereas TNC expression was delayed and prolonged. A short course of neonatal steroids impairs the first phase of alveolarization, most likely by altering the TNC and elastin expression. Due to an overshooting catch-up during the second phase of alveolarization, the differences disappear when the animals reach adulthood.

Tension-band wiring of olecranon fractures - Biomechanical analysis of different fixation techniques

Tension-band wiring is a recognised standard treatment for fixation of olecranon fractures. The classical operation technique is well known and widespread among the orthopaedic surgeons. Nevertheless complications like K-wire migration or skin perforation and difficult technical as well as anatomical prerequisites require better-adapted operation fixation methods. In older female patients a cut through of the Kirschner wires with concomitant secondary displacement was observed. We intent to develop a new, better adapted operation technique for olecranon fractures in the old patients, in order to decrease complications and follow-up procedures. In this study we compare two different K-wire positions: 10 models of the classical AO tension-banding to 10 models with adapted K-wire insertion. In this group the K-wire passes from the tip of the olecranon to the posterior cortical of the distal fragment of the ulna. We tested maximal failure load, maximal opening angle as well as maximal work to achieve maximal force. In either technique we were able to determine different variables: a maximal failure load of more than 600N (p = 0.94) for both fixation methods and a maximal opening angle for both techniques of about 10° (p = 0.86). To achieve the maximal force our modified technique required a slightly increased work (p = 0.16). In this study no statistical significant differences between the two fixation techniques was shown. This leads to the conclusion that the modified version is comparable to the classical operation technique considering the stability, but due to the adaption of the angle in the modified procedure, less lesions of neurovascular structures on the volar side can be expected. To support our findings cadaver studies are needed for further investigations.