Annals of biomedical engineering
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In this paper, the problem of endotracheal intubation confirmation is addressed. Endotracheal intubation is a complex procedure which requires high skills and the use of secondary confirmation devices to ensure correct positioning of the tube. A novel confirmation approach, based on video images classification, is introduced. ⋯ The image classification algorithm was applied off-line using a leave-one-case-out method. The results show that the system correctly classified 1517 out of 1600 (94.8%) of the cow-intubation images, and 340 out of the 358 human images (95.0%). The classification results compared favorably with a "standard" GMM approach utilizing textural based features, as well as with a state-of-the-art classification method, tested on the cow-intubation dataset.
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In patients with severe hemorrhage, complications such as shock or death may occur if the patient is not treated appropriately and expeditiously. To create a hemostat kit for severe hemorrhage, ultraviolet light irradiation was applied to photocrosslinkable chitosan hydrogel and calcium alginate. As a hemorrhage model, the femoral arteries and veins of anesthetized rats were cut. ⋯ WBC count increased 1 day after hemostasis. AST and ALT increased 1 day after hemostasis, but it decreased 3 days later. The photocrosslinkable chitosan hydrogel and calcium alginate were biodegraded at 3 and 28 days, respectively, by neutrophils and keratinocyte chemoattractant.
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Comparative Study
Validation of a semi-classical signal analysis method for stroke volume variation assessment: a comparison with the PiCCO technique.
This study proposes a Semi-Classical Signal Analysis (SCSA) method for stroke volume (SV) variations assessment from arterial blood pressure measurements. One of the SCSA parameters, the first systolic invariant (INVS₁), has been shown to be linearly related to SV. To technically validate this approach, the comparison between INVS₁ and SV measured with the currently used PiCCO technique was performed during a 15-min recording in 20 mechanically ventilated patients in intensive care. A strong correlation was estimated by linear regression and cross-correlation analysis (mean coefficient = 0.90 ± 0.01 SEM at the two tests).
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This article investigates the possibility of extracting gastric motility (GM) information from finger photoplethysmographic (PPG) signals non-invasively. Now-a-days measuring GM is a challenging task because of invasive and complicated clinical procedures involved. It is well-known that the PPG signal acquired from finger consists of information related to heart rate and respiratory rate. ⋯ The coherence analysis results demonstrate that a moderate coherence (range 0.5-0.7, SD 0.13, p < 0.05) exists between EGG and PPG signal in the "slow wave" frequency band, without any significant change in the level of coherence in postprandial state. These results indicate that finger PPG signal contains GM-related information. The findings are sufficiently encouraging to motivate further exploration of finger PPG as a non-invasive source of GM-related information.
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Millions of people worldwide are diagnosed each year with valvular heart disease, resulting in hundreds of thousands of valve replacement operations. Prosthetic valve replacements are designed to correct narrowing or backflow through the valvular orifice. Although commonly used, these therapies have serious disadvantages including morbidity associated with long-term anticoagulation and limited durability necessitating repeat operations. ⋯ Tissue engineered heart valves hold promise as a viable substitute to outperform existing valve replacements. An essential component to the development of tissue engineered heart valves is a bioreactor. It is inside the bioreactor that the scaffold and cells are gradually conditioned to the biochemical and mechanical environment of the valve to be replaced.