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These Ecole polytechnique federale de Lausanne EPFL, n° 2872 (2003)Section de microtechniqueFaculte des sciences et techniques de l'ingenieurInstitut de microelectronique et microsystemesJury: Patrick J. French, Jean-Jaques Gonvers,... more
These Ecole polytechnique federale de Lausanne EPFL, n° 2872 (2003)Section de microtechniqueFaculte des sciences et techniques de l'ingenieurInstitut de microelectronique et microsystemesJury: Patrick J. French, Jean-Jaques Gonvers, Max-Olivier Hongler, Jean-Marc Vesin Public defense: 2003-11-26 Reference doi:10.5075/epfl-thesis-2872Print copy in library catalog Record created on 2005-03-16, modified on 2016-08-08
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A glass pill for digestive motility tracking with wireless communication is presented. The pill encapsulates three magnetic transmitter coils with a 125 kHz signal, the circuitry required to control the magnetic coil output and the... more
A glass pill for digestive motility tracking with wireless communication is presented. The pill encapsulates three magnetic transmitter coils with a 125 kHz signal, the circuitry required to control the magnetic coil output and the battery. The system provides real time location of the pill inside the digestive tract of the patient using an external detector housed in a wearable jacket. The custom integrated circuit for this application reduces bill-of-materials (BOM) count and significant reduction in power consumption therefore resulting in further size reduction by adapting a smaller battery package. The outcome of the circuit integration enables the glass pill for pediatric use while providing a total pill diameter of 6 mm. The glass pill system operates continuously for 48 hours with a 1.55 V 8 mAh coin cell battery with an average power consumption of 250 microwatts.
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A CMOS integrated RF receiver of a glass pill for tracking motility in the gastrointestinal (GI) tract is presented. The receiver detects a 125 kHz downlink synchronization signal that is sent from an external base station, which is used... more
A CMOS integrated RF receiver of a glass pill for tracking motility in the gastrointestinal (GI) tract is presented. The receiver detects a 125 kHz downlink synchronization signal that is sent from an external base station, which is used to trigger the transmission of the 3-axis pill position and also to change the tuning parameters of the receiver system. The incoming downlink RF signal also includes the tuning parameters for the 10-bit resolution adjustable internal ring-oscillator, which generates a 4 MHz clock for providing the 3-axis pill position through the 125 kHz transmitter. The receiver, which is fabricated in UMC 0.18 μm CMOS process is measured using the housing of the glass pill. Experiments show that a maximum operation distance of 80 cm between the base station and the glass pill is achieved. The total power consumption of the integrated solution provides 4.6 times reduction compared to the previous generation tracking pill.
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Research Interests: Medicine, Motility, Placebo, Anesthesia, Oxycodone, and 8 moreOpioids, Clinical Sciences, Ambulatory, Capsule, Opioid, Colon, Neurosciences, and crossover study
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Research Interests: Nonparametric Statistics, Gastroenterology, Medicine, Diarrhea, Motility, and 15 moreHumans, Internal Medicine, Female, Male, Clinical Sciences, Aged, Middle Aged, Adult, Muscle contraction, Gastrointestinal Transit Time, Neuroendocrine Tumors, Gastric Emptying, Chromogranin A, Octreotide, and Carcinoid Syndrome
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Digestive motility was studied in the rat using a miniaturized version of the Magnet Tracking system which monitored the progression of a small magnetic pill through the entire digestive tract. The dynamics of movement was followed and... more
Digestive motility was studied in the rat using a miniaturized version of the Magnet Tracking system which monitored the progression of a small magnetic pill through the entire digestive tract. The dynamics of movement was followed and three‐dimensional (3‐D) images of digestive tract were generated. After a retention period in the stomach and rapid passage through duodenum, the magnet progressed along the small intestine with gradually decreasing speed and longer stationary periods. It remained in the caecum for variable intervals. In the colon, periods of progress alternated with long quiescent periods. Gastric activity oscillated at 5–6 min−1. In the small intestine, two frequency domains coexisted, showing independent modulations and proximo‐distal gradients (40 to >32 and 28 to >20 min−1). Caecal oscillations were of 1.5 min−1. The data allowed the magnet location and calculation of gastric and small intestinal transit times (58 ± 36 and 83 ± 14 min respectively), both significantly prolonged by oleate administration (243 ± 130 and 170 ± 45 min respectively). Magnet Tracking is a non‐invasive tool to study the in vivo spatial and temporal organization of gastrointestinal motility in the rat.
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A new minimally invasive technique allowing for anatomical mapping and motility studies along the entire human digestive system is presented. The technique is based on continuous tracking of a small magnet progressing through the... more
A new minimally invasive technique allowing for anatomical mapping and motility studies along the entire human digestive system is presented. The technique is based on continuous tracking of a small magnet progressing through the digestive tract. The coordinates of the magnet are calculated from signals recorded by 16 magnetic field sensors located over the abdomen. The magnet position, orientation and trajectory are displayed in real time. Ten young healthy volunteers were followed during 34 h. The technique was well tolerated and no complication was encountered. The information obtained was 3-D configuration of the digestive tract and dynamics of the magnet displacement (velocity, transit time, length estimation, rhythms). In the same individual, repeated examination gave very reproducible results. The anatomical and physiological information obtained corresponded well to data from current methods and imaging. This simple, minimally invasive technique permits examination of the entire digestive tract and is suitable for both research and clinical studies. In combination with other methods, it may represent a useful tool for studies of GI motility with respect to normal and pathological conditions.
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Reference LTS-POSTER-2009-001 URL: http://www.bbt.admin.ch/kti/projektfoerderung/00240/00242/00690/index.html?lang=en Record created on 2009-01-07, modified on 2016-08-08
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BackgroundGastrointestinal (GI) dysmotility may present secondary to inflammatory bowel disease. The main aim of this study was to investigate GI motility in ulcerative colitis (UC) patients during severe disease activity.MethodsTwenty... more
BackgroundGastrointestinal (GI) dysmotility may present secondary to inflammatory bowel disease. The main aim of this study was to investigate GI motility in ulcerative colitis (UC) patients during severe disease activity.MethodsTwenty patients with severe UC were studied with a novel telemetric capsule system (3D‐Transit) designed for minimally invasive, ambulatory assessment of total and regional GI transit times. Ten patients were available for follow‐up during remission. Data were compared to those of 20 healthy subjects (HS).Key ResultsTotal GI transit time was significantly longer in patients with severe UC (median 44.5 h [range 9.9–102.7 h]) than in HS (median 27.6 h [range 9.6–56.4 h]) (p = 0.032). Additionally, during severe UC, transit time was prolonged through the proximal colon (p = 0.003) and there were strong trends toward longer than normal small intestinal transit time (HS: median 4.9 h [range 3.4–8.3 h] vs severe UC patients: median 5.9 h [range 3.9–11.9 h]; p = 0.053) and colorectal transit times (HS: median 18.2 h [range 1.5–43.7] vs severe UC patients: median 34.9 h [range 0.4–90.9 h]; p = 0.056). Our data further indicate that total GI and colorectal transit times may be prolonged in UC during early remission.Conclusions & InferencesTotal GI transit times are significantly prolonged during severe UC.
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We present a new graphical tool to investigate the time evolution of phase-synchronization clusters and apply it to a computer model of the intestine consisting of coupled oscillators. The method estimates the synchronized zones using a... more
We present a new graphical tool to investigate the time evolution of phase-synchronization clusters and apply it to a computer model of the intestine consisting of coupled oscillators. The method estimates the synchronized zones using a covariance analysis of the electrical activity to detect any linear relationship between segments of the intestine. Synchronization expresses itself by the formation, merging and
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Research Interests: Medicine and Smartwatch
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Background Bipolar voltage (BV) electrograms for left atrial (LA) substrate characterization depend on catheter design and electrode configuration. Aims The aim of the study was to investigate the relationship between the BV amplitude... more
Background Bipolar voltage (BV) electrograms for left atrial (LA) substrate characterization depend on catheter design and electrode configuration. Aims The aim of the study was to investigate the relationship between the BV amplitude (BVA) using four catheters with different electrode design and to identify their specific LA cutoffs for scar and healthy tissue. Methods and results Consecutive high-resolution electroanatomic mapping was performed using a multipolar-minielectrode Orion catheter (Orion-map), a duo-decapolar circular mapping catheter (Lasso-map), and an irrigated focal ablation catheter with minielectrodes (Mifi-map). Virtual remapping using the Mifi-map was performed with a 4.5 mm tip-size electrode configuration (Nav-map). BVAs were compared in voxels of 3 × 3 × 3 mm3. The equivalent BVA cutoff for every catheter was calculated for established reference cutoff values of 0.1, 0.2, 0.5, 1.0, and 1.5 mV. We analyzed 25 patients (72% men, age 68 ± 15 years). For scar tis...
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Aims Opioid treatment is associated with gastrointestinal (GI) side effects, known as opioid-induced bowel dysfunction (OIBD). Symptoms of OIBD are caused by opioid receptor activation in the enteric nervous system, which results in... more
Aims Opioid treatment is associated with gastrointestinal (GI) side effects, known as opioid-induced bowel dysfunction (OIBD). Symptoms of OIBD are caused by opioid receptor activation in the enteric nervous system, which results in increased GI transit time and increased faecal volume in the colon. OIBD can be experimentally induced in healthy participants through oral oxycodone treatment. The aim of this study was to investigate whether administration of naloxegol, a peripherally restricted opioid antagonist, could reduce GI symptoms, GI transit time, and colorectal volume, using an experimental model of OIBD. Methods In a double blind crossover trial, twenty-five healthy males were randomly assigned to a six day treatment of oral oxycodone in combination with either oral naloxegol or placebo. At baseline and at day six, participants filled in the Patient Assessment of Constipation Symptom questionnaire, and colorectal volume was quantified with a magnetic resonance imaging method...
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BackgroundBipolar voltage (BV) electrograms for left atrial (LA) substrate characterization depend on catheter design and electrode configuration. The aim of the study was to investigate the relationship between the BV amplitude (BVA)... more
BackgroundBipolar voltage (BV) electrograms for left atrial (LA) substrate characterization depend on catheter design and electrode configuration. The aim of the study was to investigate the relationship between the BV amplitude (BVA) using four different catheters and to identify their specific LA cutoffs for scar and healthy tissue.MethodsConsecutive high-resolution electroanatomic mapping was performed using a multipolar Orion catheter (Orion-map), a duo-decapolar variable circular mapping catheter (Lasso-Map) and an irrigated focal ablation catheter with minielectrodes (Mifi-map). Virtual remapping using the Mifi-map was performed with a 4.5 mm tip-size electrode configuration (Nav-map). BVAs were compared in voxels of 3×3×3 mm3. The equivalent BVA cutoff for every catheter was calculated for established reference cutoff values of 0.1 mV, 0.2 mV, 0.5 mV, 1.0 mV, and 1.5 mV.ResultsWe analyzed 25 patients (72% men, age 68±15 years). For scar tissue, a 0.5 mV cutoff using the Nav c...
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A glass pill for digestive motility tracking with wireless communication is presented. The pill encapsulates three magnetic transmitter coils with a 125 kHz signal, the circuitry required to control the magnetic coil output and the... more
A glass pill for digestive motility tracking with wireless communication is presented. The pill encapsulates three magnetic transmitter coils with a 125 kHz signal, the circuitry required to control the magnetic coil output and the battery. The system provides real time location of the pill inside the digestive tract of the patient using an external detector housed in a wearable jacket. The custom integrated circuit for this application reduces bill-of-materials (BOM) count and significant reduction in power consumption therefore resulting in further size reduction by adapting a smaller battery package. The outcome of the circuit integration enables the glass pill for pediatric use while providing a total pill diameter of 6 mm. The glass pill system operates continuously for 48 hours with a 1.55 V 8 mAh coin cell battery with an average power consumption of 250 microwatts.