Robust tracking of deformable anatomical structures with severe occlusions using deformable geometrical primitives.

BACKGROUND AND OBJECTIVE: Surgical robotics tends to develop cognitive control architectures to provide certain degree of autonomy to improve patient safety and surgery outcomes, while decreasing the required surgeons' cognitive load dedicated to low level decisions. Cognition needs workspace perception, which is an essential step towards automatic decision-making and task planning capabilities. Robust and accurate detection and tracking in minimally invasive surgery suffers from limited visibility, occlusions, anatomy deformations and camera movements. METHOD: This paper develops a robust methodology to detect and track anatomical structures in real time to be used in automatic control of robotic systems and augmented reality. The work focuses on the experimental validation in highly challenging surgery: fetoscopic repair of Open Spina Bifida. The proposed method is based on two sequential steps: first, selection of relevant points (contour) using a Convolutional Neural Network and, second, reconstruction of the anatomical shape by means of deformable geometric primitives. RESULTS: The methodology performance was validated with different scenarios. Synthetic scenario tests, designed for extreme validation conditions, demonstrate the safety margin offered by the methodology with respect to the nominal conditions during surgery. Real scenario experiments have demonstrated the validity of the method in terms of accuracy, robustness and computational efficiency. CONCLUSIONS: This paper presents a robust anatomical structure detection in present of abrupt camera movements, severe occlusions and deformations. Even though the paper focuses on a case study, Open Spina Bifida, the methodology is applicable in all anatomies which contours can be approximated by geometric primitives. The methodology is designed to provide effective inputs to cognitive robotic control and augmented reality systems that require accurate tracking of sensitive anatomies.

Robot assisted Fetoscopic Laser Coagulation: Improvements in navigation, re-location and coagulation.

Fetoscopic Laser Coagulation (FLC) for Twin to Twin Transfusion Syndrome is a challenging intervention due to the working conditions: low quality images acquired from a 3 mm fetoscope inside a turbid liquid environment, local view of the placental surface, unstable surgical field and delicate tissue layers. FLC is based on locating, coagulating and reviewing anastomoses over the placenta's surface. The procedure demands the surgeons to generate a mental map of the placenta with the distribution of the anastomoses, maintaining, at the same time, precision in coagulation and protecting the placenta and amniotic sac from potential damages. This paper describes a teleoperated platform with a cognitive-based control that provides assistance to improve patient safety and surgery performance during fetoscope navigation, target re-location and coagulation processes. A comparative study between manual and teleoperated operation, executed in dry laboratory conditions, analyzes basic fetoscopic skills: fetoscope navigation and laser coagulation. Two exercises are proposed: first, fetoscope guidance and precise coagulation. Second, a resolved placenta (all anastomoses are indicated) to evaluate navigation, re-location and coagulation. The results are analyzed in terms of economy of movement, execution time, coagulation accuracy, amount of coagulated placental surface and risk of placenta puncture. In addition, new metrics, based on navigation and coagulation maps evaluate robotic performance. The results validate the developed platform, showing noticeable improvements in all the metrics.

Intraamniotic sealing of fetoscopic membrane defects in ex vivo and in vivo sheep models using an integrated semirigid bioadhesive patch.

BACKGROUND: Preterm prelabor rupture of membranes is the most frequent complication of fetoscopic surgery. Strategies to seal the membrane defect created by fetoscopy have been attempted with little success. We previously developed an integrated semirigid bioadhesive patch composed of silicone and hydroxypropyl methylcellulose that achieved ex vivo sealing of membrane defects. OBJECTIVE: To evaluate the feasibility of the insertion of our integrated semirigid bioadhesive patches using a fetoscopic technique and to test the adhesion in ex vivo human membranes and in an in vivo ovine model. STUDY DESIGN: An experimental study involving 2 experiments: (1) ex vivo-human fetal membranes were mounted in a custom-designed model with saline solution simulating intraamniotic pressure. The insertion of 2 different bioadhesive patches made of silicone-hydroxypropyl methylcellulose and silicone-polyurethane-hydroxypropyl methylcellulose was performed through a 12-Fr cannula mimicking fetoscopic surgery technique. The experiment was repeated 10 times with membranes from different donors. Measures included insertion time, successful insertion, and adhesion at 5 minutes; (2) in vivo-16 patches of silicone-hydroxypropyl methylcellulose were inserted by fetoscopy in the amniotic cavity of pregnant sheep (4 bioadhesives per animal, in 4 ewes). Measures included successful insertion, adhesion at 5 minutes, and adhesion at the end of surgery. RESULTS: In the ex vivo insertion study, there was no difference in the insertion time between silicone-hydroxypropyl methylcellulose and silicone-polyurethane-hydroxypropyl methylcellulose patches (P=.49). Insertion was successful in all cases, but complete adhesion at 5 minutes was superior for silicone-hydroxypropyl methylcellulose (P=.02). In the in vivo study, insertion of silicone-hydroxypropyl methylcellulose by fetoscopy was feasible and successful in all cases, and no complications were reported. Adhesion persisted at 5 minutes and at the end of the surgery in 68.8% and 56.3% of the patches, respectively. CONCLUSION: We describe the feasibility of deploying through a fetoscopic trocar a semirigid silicone-hydroxypropyl methylcellulose patch that seals fetal membranes after an invasive fetal procedure. The results warrant further research for improving long-term adhesion and developing a clinically applicable system.

in vivo Monitoring with micro-implantable hypoxia sensor based on tissue acidosis.

Hypoxia is a common medical problem, sometimes difficult to detect and caused by different situations. Control of hypoxia is of great medical importance and early detection is essential to prevent life threatening complications. However, the few current methods are invasive, expensive, and risky. Thus, the development of reliable and accurate sensors for the continuous monitoring of hypoxia is of vital importance for clinical monitoring. Herein, we report an implantable sensor to address these needs. The developed device is a low-cost, miniaturised implantable electrochemical sensor for monitoring hypoxia in tissue by means of pH detection. This technology is based on protonation/deprotonation of polypyrrole conductive polymer. The sensor was optimized in vitro and tested in vivo intramuscularly and ex vivo in blood in adult rabbits with respiration-induced hypoxia and correlated with the standard device ePOCTM. The sensor demonstrated excellent sensitivity and reproducibility; 46.4 ± 0.4 mV/pH in the pH range of 4-9 and the selectivity coefficient exhibited low interference activity in vitro. The device was linear (R2 = 0.925) with a low dispersion of the values (n = 11) with a cut-off of 7.1 for hypoxia in vivo and ex vivo. Statistics with one-way ANOVA (α = 0.05), shows statistical differences between hypoxia and normoxia states and the good performance of the pH sensor, which demonstrated good agreement with the standard device. The sensor was stable and functional after 18 months. The excellent results demonstrated the feasibility of the sensors in real-time monitoring of intramuscular tissue and blood for medical applications.

Micro-needle implantable electrochemical oxygen sensor: ex-vivo and in-vivo studies.

Oxygen is vital for energy metabolism in mammals and the variability of the concentration is considered a clinical alert for a wide range of metabolic malfunctions in medicine. In this article, we describe the development and application of a micro-needle implantable platinum-based electrochemical sensor for measuring partial pressure of oxygen in intramuscular tissue (in-vivo) and vascular blood (ex-vivo). The Pt-Nafion® sensor was characterized morphological and electrochemically showing a higher sensitivity of -2.496 nA/mmHg (-1.495 nA/µM) when comparing with its bare counterpart. Our sensor was able to discriminate states with different oxygen partial pressures (pO2) for ex-vivo (blood) following the same trend of the commercial gas analyzer used as standard. For in-vivo (intramuscular) experiments, since there is not a gold standard for measuring pO2 in tissue, it was not possible to correlate the obtained currents with the pO2 in tissue. However, our sensor was able to detect clear statistical differences of O2 between hyperoxia and hypoxia states in tissue.

Validation of the Fetal Lamb Model of Spina Bifida.

A randomized trial demonstrated that fetal spina bifida (SB) repair is safe and effective yet invasive. New less invasive techniques are proposed but are not supported by adequate experimental studies. A validated animal model is needed to bridge the translational gap to the clinic and should mimic the human condition. Introducing a standardized method, we comprehensively and reliably characterize the SB phenotype in two lamb surgical models with and without myelotomy as compared to normal lambs. Hindbrain herniation measured on brain magnetic resonance imaging (MRI) was the primary outcome. Secondary outcomes included gross examination with cerebrospinal fluid (CSF) leakage test, neurological examination with locomotor assessment, whole-body MRI, motor and somatosensory evoked potentials; brain, spinal cord, hindlimb muscles, bladder and rectum histology and/or immunohistochemistry. We show that the myelotomy model best phenocopies the anatomy, etiopathophysiology and symptomatology of non-cystic SB. This encompasses hindbrain herniation, ventriculomegaly, posterior fossa anomalies, loss of brain neurons; lumbar CSF leakage, hindlimb somatosensory-motor deficit with absence of motor and somatosensory evoked potentials due to loss of spinal cord neurons, astroglial cells and myelin; urinary incontinence. This model obtains the highest validity score for SB animal models and is adequate to assess the efficacy of novel fetal therapies.

Vision Based Robot Assistance in TTTS Fetal Surgery.

This paper presents an accurate and robust tracking vision algorithm for Fetoscopic Laser Photo-coagulation (FLP) surgery for Twin-Twin Transfusion Syndrome (TTTS). The aim of the proposed method is to assist surgeons during anastomosis localization, coagulation and review using a tele-operated robotic system. The algorithm computes the relative position of the fetoscope tool tip with respect to the placenta, via local vascular structure registration. The algorithm uses image features (local superficial vascular structures of the placenta's surface) to automatically match consecutive fetoscopic images. It is composed of three sequential steps: image processing (filtering, binarization and vascular structures segmentation); relevant Points Of Interest (POIs) seletion; and image registration between consecutive images. The algorithm has to deal with the low quality of fetoscopic images, the liquid and dirty environment inside the placenta jointly with the thin diameter of the fetoscope optics and low amount of environment light reduces the image quality. The obtained images are blurred, noisy and with very poor color components. The tracking system has been tested using real video sequences of FLP surgery for TTTS. The computational performance enables real time tracking, locally guiding the robot over the placenta's surface with enough accuracy.

Preterm infant showed better object handling skills in a neonatal intensive care unit during silence than with a recorded female voice.

AIM: This study compared whether preterm infants showed better tactile abilities during silence or when they heard a prerecorded female voice at different intensities. METHODS: We studied 74 preterm infants of 28-35 weeks' postconceptional age who were admitted to a French neonatal intensive care unit from 2014 to 2017. They were presented with wooden objects, one smooth and one angled, at various points during silence (n = 26) or while listening to a female voice at +5 (n = 24) or +15 decibels (n = 24) inside their incubator. We compared the conditions to see if there was any difference in how the infants handled the objects and also compared familiar and unfamiliar objects. RESULTS: The preterm infants showed better handling skills and only displayed effective discrimination, during silence. We found that 27.1% of the infants exposed to female voices failed to get habituated to the object, compared to 7.7% in the silence condition (p < 0.05) and success during the voice conditions required more trials (6.1 vs. 5.3) than the silence condition (p = 0.05). The different voice intensities made no difference. CONCLUSION: Being exposed to a female voice had a negative impact on preterm infants' tactile sensory learning, regardless of its intensity.

Cord Blood Biomarkers of Cardiac Dysfunction and Damage in Term Growth-Restricted Fetuses Classified by Severity Criteria.

OBJECTIVE: To assess cardiovascular function and damage in term small-for-gestational-age (SGA) and intrauterine growth-restricted (IUGR) fetuses by echocardiography and biomarkers in cord blood. METHODS: This was a cohort study including 60 normal fetuses and 47 term small fetuses subclassified as small for gestational age (SGA) with estimated fetal weight (EFW) between the 3rd and 9th centiles and normal fetoplacental Doppler (n = 14) or intrauterine growth restriction (IUGR, n = 33) if EFW <3rd centile or EFW <10th centile together with cerebroplacental ratio <5th and/or mean uterine artery pulsatility index >95th centile. Fetal echocardiography included left myocardial performance index (MPI) and annular plane systolic excursion. Fetal B-type natriuretic peptide (BNP), troponin-I, heart-type fatty acid-binding proteins (H-FABP), and homocysteine concentrations were measured in cord blood collected at delivery. RESULTS: Both SGA and IUGR cases presented echocardiographic signs of systolic and diastolic dysfunction with increased MPI (mean controls 0.43 [SD 0.12], SGA 0.47 [0.03], and IUGR 0.57 [0.08], p < 0.01) and decreased mitral annular plane systolic excursion (controls 6.0 mm [1.0], SGA 5.5 mm [0.6], and IUGR 4.9 mm [0.8], p = 0 01). IUGR fetuses presented increased levels of cord blood BNP (controls 17.2 pg/mL [11.5], SGA 22.4 pg/mL [10.7], and IUGR 31.2 pg/mL [26.8], p < 0.01). Troponin I was increased in both SGA and IUGR cases (controls 0.004 ng/mL [0.007], SGA 0.012 ng/mL [0.02], and IUGR 0.018 ng/mL [0.05], p < 0.01). H-FABP and homocysteine showed similar values among groups. CONCLUSIONS: Cardiac dysfunction and cell damage is a common feature of term SGA and IUGR fetuses despite of the severity criteria for perinatal outcome. Further research is needed to evaluate the potential long-term consequences on their cardiovascular system.

Sound levels in a neonatal intensive care unit significantly exceeded recommendations, especially inside incubators.

AIM: This study measured sound levels in a 2008 built French neonatal intensive care unit (NICU) and compared them to the 2007 American Academy of Pediatrics (AAP) recommendations. The ultimate aim was to identify factors that could influence noise levels. METHODS: The study measured sound in 17 single or double rooms in the NICU. Two dosimeters were installed in each room, one inside and one outside the incubators, and these conducted measurements over a 24-hour period. The noise metrics measured were the equivalent continuous sound level (Leq ), the maximum noise level (Lmax ) and the noise level exceeded for 10% of the measurement period (L10 ). RESULTS: The mean Leq , L10 and Lmax were 60.4, 62.1 and 89.1 decibels (dBA), which exceeded the recommended levels of 45, 50 and 65 dBA (p < 0.001), respectively. The Leq inside the incubator was significantly higher than in the room (+8 dBA, p < 0.001). None of the newborns' characteristics, the environment or medical care was correlated to an increased noise level, except for a postconceptional age below 32 weeks. CONCLUSION: The sound levels significantly exceeded the AAP recommendations, particularly inside incubators. A multipronged strategy is required to improve the sound environment and protect the neonates' sensory development.

Sound Interferes with the Early Tactile Manual Abilities of Preterm Infants.

Premature birth is a sudden change of the sensory environment of a newborn, while their senses are still in development, especially in the stressful and noisy environment of the NICU. The study aimed to evaluate the effect of noise on the early tactile manual abilities of preterm infants (between 29 and 35 weeks PCA). Infants were randomly assigned to one of the two conditions: Silence and Noise. For each condition, two phases were introduced: a habituation phase (repeated presentation of the same object, prism or cylinder), followed by a test phase (presentation of the familiar or a novel object). In the Silence condition, they received the tactile habituation and test phases: In the Noise condition, they went through the same phases, while an alarm sounded. Sixty-three preterm infants were included. They displayed a strong and effective ability to memorize tactile manual information and to detect the difference between two shape features, but this ability seems to be impaired by the concomitant exposure to an alarm sound. This study is the first to highlight the effect of a negative stimulus on sensory functioning in premature infants. It reinforces the importance of developing environmental measures to lower the sound level in NICUs.

Use of placental growth factor and uterine artery doppler pulsatility index in pregnancies involving intrauterine fetal growth restriction or preeclampsia to predict perinatal outcomes.

AIM: The potential of uterine artery (UA) Doppler pulsatility index (PI) and maternal serum placental growth factor (PlGF) level to predict perinatal outcome was explored in pregnancies complicated by intrauterine fetal growth restriction (IUGR) or preeclampsia (PE). METHODS: This longitudinal, prospective, and case-controlled study was conducted over a period of 24 months. At-risk pregnancies involving small-for-gestational-age (SGA) fetuses, IUGR, gestational hypertension (GH), or PE were investigated, analyzing UA Doppler PI findings and maternal PlGF levels determined at the time of diagnosis (third trimester). RESULTS: UA Doppler PI and maternal serum PlGF values differed significantly in pregnancies complicated by IUGR and/or PE (vs. SGA or GH, p < 0.01). In the context of IUGR or PE, both parameters also differed significantly by perinatal outcome (adverse vs. normal, p < 0.01), although no predictive advantage over UA Doppler PI alone was conferred by adding a PlGF assay. CONCLUSION: UA Doppler PI and maternal serum PlGF determinations in the third trimester help identify pregnancies at the highest risk of adverse perinatal outcomes due to IUGR and/or PE. Although joint testing confers no predictive benefit over UA Doppler PI alone, the two diagnostics are interchangeable for this purpose.

Echocardiography allows more accurate placement of peripherally inserted central catheters in low birthweight infants.

AIM: The use of plain radiographs provides limited information on the placement of peripherally inserted central catheters (PICCs). Moreover, changes in upper extremity positioning cause migration of the catheters in neonates. This study aimed to investigate the use of echocardiography for determining catheter tip position, compared with plain radiographs, in low birthweight (LBW) infants in a tertiary neonatal intensive care unit. METHODS: The study examined the placement of 109 catheters in 89 infants born between September 2010 and December 2012. The placement of these catheters was controlled by echocardiography, with the patient's shoulder in adduction and the elbow in flexion. The number of catheter tips, echocardiographically identified within the heart, was expressed as a percentage of the total catheters deemed to be well positioned on plain radiographs. RESULTS: The number of catheter tips that were echocardiographically identified within the heart was significant (25%, p < 0.001). Twenty-three catheters were repositioned to be outside of the heart, without any complications. CONCLUSION: This study demonstrated the value of echocardiography for identifying the positioning of catheter tips in LBW infants. Echocardiography, coupled with initial plain radiographs, should be the gold standard for assessing PICC tip positions in those infants.

Factores etiopatogénicos de la prematuridad en el hospital universitario Sant Joan de Déu de Barcelona / Etiopathogenic factors of prematurity in the Sant Joan de Déu Hospital in Barcelona (Spain)

Objetivo. Determinar la tasa de partos prematuros durante el 2010 en el Hospital Universitario Sant Joan de Déu de Barcelona, y clasificarlos según la causa principal utilizando un algoritmo de asignación etiológica para establecer las principales causas de parto prematuro. Sujetos y métodos. Se revisan todos los partos prematuros de menos de 37 semanas de gestación que se producen en el Hospital Universitario Sant Joan de Déu de Barcelona durante 2010 (396 casos), y se les asigna un grupo de etiología principal. Resultados. La tasa de parto prematuro es de 9,8%. Las causas inflamatorias representan el 36% de todos los partos prematuros seguidas de las causas idiopáticas (29%). En los partos prematuros de gestaciones múltiples las causas inflamatorias alcanzan el 44%. Conclusiones. Las causas inflamatorias son la principal etiología de parto prematuro, siendo más frecuente en las gestaciones múltiples (AU)

Objective. To determine the rate of preterm births in 2010 at the Sant Joan de Déu University Hospital in Barcelona, and classify them according to the main cause by using a mapping algorithm to establish the main etiological causes of preterm birth. Subjects and methods. All preterm births at less than 37 weeks’ gestation occurring in the Sant Joan de Déu University Hospital in 2010 (n=396) were reviewed and assigned to a group according to their primary etiology. Results. The preterm birth rate was 9.8%. Inflammatory causes accounted for 36% of all preterm births followed by idiopathic causes (29%). In preterm deliveries of multiple gestations, inflammatory causes accounted for 44%. Conclusions. Inflammatory causes are the main etiology of preterm births and are more common in multiple gestations (AU)

Guías colombianas para el manejo del acné: una revisión basada en la evidencia por el Grupo Colombiano de Estudio en Acné

El acné es una enfermedad inflamatoria crónica que afecta, principalmente, adolescentes y adultos jóvenes. Se calcula que antes de los 21 años entre el 80 y el 90% de esta población ha estado expuesta a la enfermedad. Sin embargo, el acné puede persistir después de los 21 años y se sabe que 12% de las mujeres mayores de 25 años aún sufren de acné facial. El arsenal terapéutico para el acné consta de medicamentos tópicos y sistémicos que han demostrado su eficacia en la reducción de las lesiones. El mecanismo de acción de estos medicamentos está orientado, al menos, a uno de los cuatro factores fisiopatológicos reconocidos como responsables de la formación de las lesiones del acné, a saber: trastornos de la queratinización, hipersecreción sebácea, proliferación de Propionibacterium acnes o actividad inflamatoria in situ. La elección del tratamiento apropiado depende de varios factores, como la forma clínica de la enfermedad (de retención o inflamatoria), la gravedad de la misma y la respuesta del paciente a tratamientos previos. Asimismo, y entendiendo al acné como una enfermedad de carácter crónico, el tratamiento debe incluir una fase inicial con el objetivo de lograr una mayor reducción de la extensión y gravedad de las lesiones, y una fase de mantenimiento orientada a la prevención de las recaídas o exacerbaciones. Además, el resultado del tratamiento depende del cumplimiento del mismo y para lograrlo, es fundamental una adecuada relación médico-paciente. Este documento presenta el resultado de una revisión actualizada de la literatura, que incluye guías nacionales e internacionales para el manejo del acné y formula recomendaciones terapéuticas basadas en el mejor nivel de “evidencia” que se encontró. Su implementación permitirá la unificación de criterios con el objetivo de ofrecer un mejor manejo a los pacientes con la enfermedad, evitando así sus secuelas físicas y emocionales. Por otro lado, las guías presentan un marco científico y conceptual con la suficiente validez para su inclusión en los protocolos del plan obligatorio de salud.