Handling Topological Changes during Elastic Registration: Application to Augmented Reality in Laparoscopic Surgery

International audiencePurpose: Locating the internal structures of an organ is a critical aspect of many surgical procedures. Minimally invasive surgery, associated with augmented reality techniques, offers the potential to visualize inner structures, allowing for improved analysis, depth perception or for supporting planning and decision systems.Methods: Most of the current methods dealing with rigid or non-rigid augmented reality make the assumption that the topology of the organ is not modified. As surgery relies essentially on cutting and dissection of anatomical structures, such methods are limited to the early stages of the surgery.We solve this shortcoming with the introduction of a method for physics-based elastic registration using a single view from a monocular camera.Singularities caused by topological changes are detected and propagated to the pre-operative model. This significantly improves the coherence between the actual laparoscopic view and the model, and provides added value in terms of navigation and decision-making, e.g. by overlaying the internal structures of an organ on the laparoscopic view.Results: Our real time augmentation method is assessed on several scenarios, using synthetic objects and real organs. In all cases, the impact of our approach is demonstrated, both qualitatively and quantitatively.Conclusion: The presented approach tackles the challenge of localizing internal structures throughout a complete surgical procedure, even after surgical cuts. This information is crucial for surgeons to improve the outcome for their surgical procedure and avoid complications

Avaliação dos fatores determinantes à perda dentária em usuários de um posto de saúde em Teresina, Piauí / Evaluation of the determinants of tooth loss in users of a health center in Teresina, Piauí

Introdução: A perda dentária é considerada um problema de saúde pública que gera impactos negativos na qualidade de vida do indivíduo. Objetivo: Avaliar os fatores determinantes da perda dentária em usuários de um posto de saúde em Teresina - Piauí. Método: Foram entrevistados 384 usuários, de ambos os gêneros, com faixa etária de 15 a 60 anos de idade, através de um questionário. A amostra foi constituída por pessoas que haviam perdido pelo menos um elemento dentário. Resultados: Segundo o grau de escolaridade, predominaram os usuários com nível fundamental incompleto (47,92%), a faixa salarial mais prevalente foi entre 1 e 3 salários mínimos (68,23%) e aqueles que ganham menos de 1 salário mínimo (21,61%). Perguntou-se sobre a função dos dentes, a maioria (88,81%) respondeu triturar, mastigar, comer e morder alimentos. Em relação à forma de higienização bucal, 99,48% responderam que utilizavam escova e dentifrício, 45,31% responderam que utilizavam o fio dental, 69,53 % relataram uso de soluções para enxágue bucal e 60,16% responderam que utilizam o palito. Conclusão: Predomínio de usuários com nível fundamental incompleto e renda familiar de 1 a 3 salários mínimos. Percebe-se a necessidade de incentivo para propostas de promoção e autocuidado em saúde bucal

Statement of Second Brazilian Congress of Mechanical Ventilarion : part I

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Small Bowel Injuries

The small intestine is the most common organ to be injured in penetrating trauma and is injured in about 5–16% of blunt abdominal trauma. While surgical intervention in penetrating abdominal trauma is mostly immediate when indicated, there is a tendency toward delayed diagnosis and treatment in blunt trauma which increases the morbidity and mortality of such injuries. The presence of certain signs on physical examination should alert the healthcare provider to the higher possibility of small intestine injury; these include the seat belt sign and the presence of chance fracture. In patients who are hemodynamically stable, CT scan with IV contrasts and with or without oral contrast has been frequently used as a complementary method to the anamnesis. CT scan is less used in penetrating trauma. The treatment of traumatic small bowel injuries is surgical, and depends on the extent of the injury

Interstitial lung disease and gastroesophageal reflux disease: key role of esophageal function tests in the diagnosis and treatment

CONTEXT: Gastroesophageal reflux disease (GERD) is common in patients with respiratory disorders and interstitial lung fibrosis from diverse disease processes. However, a cause-effect relationship has not been well demonstrated. It is hypothesized that there might be more than a coincidental association between GERD and interstitial lung damage. There is still confusion about the diagnostic steps necessary to confirm the presence of GERD, and about the role of effective control of GERD in the natural history of these respiratory disorders. OBJECTIVES: To determine the prevalence of GERD in patients with respiratory disorders and lung involvement; the sensitivity of symptoms in the diagnosis of GERD; and the role of esophageal function tests (manometry and 24- hour pH monitoring) in the diagnosis and treatment of these patients. METHODS: Prospective study based on a database of 44 patients (29 females) with respiratory disorders: 16 patients had idiopathic pulmonary fibrosis, 11 patients had systemic sclerosis associated interstitial lung disease, 2 patients had polymyositis associated interstitial lung disease, 2 patients had Sjögren associated interstitial lung disease, 2 patients had rheumatoid artrithis associated interstitial lung disease, 1 patient had undifferentiated connective tissue diseases associated interstitial lung disease and 10 patients had sarcoidosis. The average forced vital capacity (% predicted) was 64.3%. All patients had esophageal function tests. RESULTS: Thirty patients (68%) had pathologic reflux (average DeMeester score: 45, normal <14.7). The average number of reflux episodes recorded 20 cm above the lower esophageal sphincter was 24. Sensitivity and specificity of heartburn were 70% and 57%, of regurgitation 43% and 57%, and of dysphagia 33% and 64%. Twelve patients with GERD underwent a laparoscopic fundoplication which was tailored to the manometric profile: three patients in which peristalsis was normal had a total fundoplication (360°) and nine patients in which the peristalsis was absent had a partial anterior fundoplication (180°). CONCLUSIONS: The results of our study show that: (a) abnormal reflux was present in about 2/3 of patients with respiratory disorders (idiophatic pulmonary fibrosis, connective tissue disorders and sarcoidosis), and it extended to the upper esophagus in most patients; (b) the sensitivity and specificity of reflux symptoms was very low; and (c) esophageal function tests were essential to establish the diagnosis of abnormal reflux, to characterize the esophageal function and guide therapy. Long term follow-up will be necessary to determine if control of reflux alters the natural history of these respiratory disorders

Near-infrared fluorescent coatings of medical devices for image-guided surgery

International audienceRapidly expanding field of image-guided surgery needs new materials for near-infrared imaging with deep tissue penetration. Here, we introduce near-infrared coating of equipment (NICE) for image-guided surgery based on a series of lipophilic cyanine-7.5 dyes with bulky hydrophobic counterions and a biocompatible polymer, poly(methyl methacrylate). The NICE material exhibits superior brightness (15-20-fold higher) and photostability compared to fluorescent coatings based on commonly used indocyanine green (ICG). It can be deposited on different surfaces and devices, such as steel and gold fiducials, silicone and PVC catheters, polymeric surgical sutures and gauzes. Such coated medical devices show excellent stability in air and buffer for 150 days. Accelerated ageing revealed their shelf-life of 3 years. They are also stable in serum-containing media, whereas ICG-based coating shows rapid dye leakage. NICE is compatible with standard sterilization protocols based on ethylene oxide and vapor. Moreover, our coating material is biocompatible, where cultured cells spread effectively without signs of cytotoxicity. Ex vivo studies suggest that NICE on fiducials can be visualized as deep as 0.5 cm, and NICE on catheters enables their visualization inside ureters and esophagus. Finally, NICE on different medical devices has been validated for image-guided surgery in porcine and human cadaver models. Thus, the developed NIR coating material emerges as a powerful tool for a variety of medical applications