This paper presents a robust multichannel lung sound recording device (LSRD) for automatic lung sound classification. Compared to common approaches, we improved the usability and the robustness against body sounds and ambient noise. We developed a novel lung sound transducer (LST) and an appropriate attachment method realized as a foam pad. For analogue prefiltering, preamplification, and digitization of the lung sound signal, we use a composition of low-cost standard audio recording equipment. Furthermore, we developed a suitable recording software. In our experiments, we show the robustness of our LSRD against ambient noise, and we demonstrate the achieved signal quality. The LSTâs microphone features a signal-to-noise ratio of SNR = 80 dB. Therefore, we obtain a bandwidth of up to a frequency of f â 2500 Hz for vesicular lung sound recordings. Compared to the attachment of the LST with self-adhesive tape, the foam pad achieves an attenuation of ambient noise of up to 50 dB in the relevant frequency range. The result of this work is a multichannel recording device, which enables a fast gathering of valuable lung sounds in noisy clinical environments without impeding the daily routines.
In this paper, we present a method for event detection in single-channel lung sound recordings. This includes the detection of crackles and breathing phase events (inspiration/expiration). Therefore, we propose an event detection approach with spectral features and bidirectional gated recurrent neural networks (BiGRNNs). In our experiments, we use multichannel lung sound recordings from lung-healthy subjects and patients diagnosed with idiopathic pulmonary fibrosis, collected within a clinical trial. We achieve an event-based F-score of F 1 ≈ 86% for breathing phase events and F 1 ≈ 72% for crackles. The proposed method shows robustness regarding the contamination of the lung sound recordings with noise, bowel and heart sounds.
Background: This study addresses a longstanding discrepancy between the observed course of the superior epigastric artery in anatomical specimens and its depiction in many German-language anatomy textbooks. While the artery typically runs ventral to the diaphragm, textbooks inaccurately describe it as passing through the sternocostal triangle (Larrey's fissure). Methods: Anatomical dissections were performed on 40 formalin-fixed cadavers at the Medical University of Vienna. The thoracic and abdominal walls were dissected, and the course of the superior epigastric artery was documented. Literature from the time of Dominique Larrey to present was reviewed to trace the origin of the incorrect anatomical description.Discussion: Findings confirm that the superior epigastric artery does not traverse Larrey's space but remains ventral to the pleural and peritoneal cavities. The erroneous description appears to have originated from a 19th-century misinterpretation by Joseph Hyrtl and was perpetuated in German-language textbooks.Conclusion: The study refutes the long-standing but incorrect description of the superior epigastric artery's course in German-language anatomy textbooks. The findings highlight the importance of revising anatomical literature to correct historical inaccuracies.
Abstract Background Delayed gastric emptying is a common feature after gastric pull-up for reconstruction following esophagectomy. Symptoms range from mild discomfort to life-threatening recurrent aspiration. Apart from the well-known and technically inevitable truncal vagotomy neither causative factors nor effective preventive measures have been clearly identified. Methods We did a retrospective study in 381 patients (317 males, 64 females; age: 22 -88 years; mean: 62,4 years), who underwent esophagectomy and gastric pull-up with cervical esophagogastrostomy between 1/2008 and 12/2017. During this period the surgical technique had been the same except that in the first phase no intervention at the pylorus had been done (N = 207), whereas in the second pyloromytomy (N = 97) and in the third (N = 110) intrapyloric injection of Botulinum-toxin was performed. Delayed gastric emptying was diagnosed by distension of the conduit with an air-fluid level on chest roentgenogram, and by symptoms and signs of regurgitation or vomiting in absence of other bowel obstruction. 122 patients had retrosternal pull-up due to transmural tumour growth or lymph-nodes, in 259 the orthotopic route was chosen. All patients were followed-up for at least three months after the operation. Results 56 patients (14,7%) developed delayed gastric emptying. Neither pyloromytomy nor injection of Botox had any effect as compared with the patients in the no-intervention period. The route of gastric pull-up had no influence either. In women (N = 15; 23,4%), however, delayed gastric emptying was significantly more frequent than in men (N = 41; 12,9%; P = 0.03). Moreover, the Body Mass Index (BMI) of patients with delayed gastric emptying (BMI = 26.6) was significantly higher than in those who had not (BMI = 24,7; P = 0.03). By multivariate analysis the influence of gender and BMI on the development of delayed gastric emptying remained significant. Conclusion The results of our single center retrospective analysis may show that both, gender and BMI might significantly influence the development of postoperative delayed gastric emptying after esophagectomy and reconstruction by gastric pull-up. For a better understanding and management of delayed gastric emptying prospective trials with larger numbers of patients are definitely needed. Disclosure All authors have declared no conflicts of interest.
Adolescent moped riders have a high risk of injury. Little is known about the causes and consequences of these injuries (Kopjar 1999). It is the aim of this study to analyse the causes and the type...
Abstract Background Esophageal, esophago-hypopharyngeal and esophago-tracheobronchial fistulae or strictures arising either de novo or following therapeutic interventions constitute serious therapeutic challenges. If conservative measures fail, pedicled muscular or myocutaneous flaps are life-saving assets. Methods During the last 10 years we treated 13 patients (11 males, 2 females; mean age: 59; range: 44–82y) with complex esophageal/hypopharyngeal problems by using pedicled muscle flaps. Results All had but one case of lye ingestion had underlying malignant disease, all but two of the latter had had chemo- and or radiotherapy. At the time of the intervention eight patients were in a critical, septic condition. There were 5 esophago-tracheal, 2 esophago-bifurcational, one esophago-colo-bronchial, and one hypopharyngo-tracheal fistula, as well as one pharyngo-cutaneous fistula all following resection/reconstruction and/or attempts of surgical closure. One patient had stricture following external irradiation, another one anastomotic stricture. We applied a total of 17 pedicled flaps: 10 pectoralis major flaps (7 of them myocutaneous, three split flaps), 5 deltoideo-pectoral myocutaneous flaps and 2 sternocleidomastoideus flaps. In 11 patients additional intermittent stenting was used. In 6 patients the respective condition healed, 4 patients could be discharged but had minor recurrent fistulae that could be handled conservatively, in three cases persisting sepsis and multiorgan failure could not be overcome. Conclusion Muscle flaps can be life-saving in large fistulae of the esophagus and the hypopharynx and are useful for refractory cervical stenosis. In presence of multiorgan dysfunction, however, healing of flaps however initially vital, is often impaired. Disclosure All authors have declared no conflicts of interest.
