Oxygen saturation Research Papers - Academia.edu (original) (raw)

Oxygenation measurements are widely used in patient care. However, most clinically available instruments currently consist of contact probes that only provide global monitoring of the patient (e.g., pulse oximetry probes) or local... more

Oxygenation measurements are widely used in patient care. However, most clinically available instruments currently consist of contact probes that only provide global monitoring of the patient (e.g., pulse oximetry probes) or local monitoring of small areas (e.g., spectroscopy-based probes). Visualization of oxygenation over large areas of tissue, without a priori knowledge of the location of defects, has the potential to improve patient management in many surgical and critical care applications. In this study, we present a clinically compatible multispectral spatial frequency domain imaging (SFDI) system optimized for surgical oxygenation imaging. This system was used to image tissue oxygenation over a large area (16×12 cm) and was validated during preclinical studies by comparing results obtained with an FDA-approved clinical oxygenation probe. Skin flap, bowel, and liver vascular occlusion experiments were performed on Yorkshire pigs and demonstrated that over the course of the experiment, relative changes in oxygen saturation measured using SFDI had an accuracy within 10% of those made using the FDA-approved device. Finally, the new SFDI system was translated to the clinic in a first-in-human pilot study that imaged skin flap oxygenation during reconstructive breast surgery. Overall, this study lays the foundation for clinical translation of endogenous contrast imaging using SFDI.

Juvenile Atlantic halibut (40.5±9.1g mean initial body mass±SD) were reared at five different levels of oxygen availability (57%, 84%, 100%, 120%, and 150% of air saturation) for 94days. The availability of oxygen significantly affected... more

Juvenile Atlantic halibut (40.5±9.1g mean initial body mass±SD) were reared at five different levels of oxygen availability (57%, 84%, 100%, 120%, and 150% of air saturation) for 94days. The availability of oxygen significantly affected the growth rate of the fish while feed conversion was not significantly different. The final size of fish reared at 57% of air saturation was significantly

OBJECTIVE. Chronic snoring that does not adhere to the criteria for a diagnosis of obstructive sleep apnea syndrome may be associated with learning and behavioral problems. We investigated the sleep structure of chronic snorers who had an... more

OBJECTIVE. Chronic snoring that does not adhere to the criteria for a diagnosis of obstructive sleep apnea syndrome may be associated with learning and behavioral problems. We investigated the sleep structure of chronic snorers who had an apnea-hypopnea index of <1 event per hour and analyzed the cyclic alternating pattern. METHODS. Fifteen successively seen chronic snorers (9.8 ± 4 years) with an apnea-hypopnea index of <1 and 15 aged-matched control subjects (10.3 ± 5 years) underwent an investigation of their sleep with the determination of non–apneic-hypopneic breathing abnormalities polysomnographic scoring using current criteria and analysis of the cyclic alternating pattern. RESULTS. Chronic snorers have evidence of flow limitations and tachypnea during sleep even if they do not present with apneas, hypopneas, and decrease in oxygen saturations. They also present with abnormal cyclic alternating pattern rates and changes in phase A of cyclic alternating pattern compared...

Our objective was to characterize sleep-disordered breathing in 88 children with achondroplasia aged 1 month to 12.6 years. At the time of their initial polysomnography, five children had previously undergone tracheostomy, and seven... more

Our objective was to characterize sleep-disordered breathing in 88 children with achondroplasia aged 1 month to 12.6 years. At the time of their initial polysomnography, five children had previously undergone tracheostomy, and seven children required supplemental oxygen. Initial polysomnography demonstrated a median obstructive apnea index of 0 (range, 0 to 19.2 apneas/hr). The median number of central apneas with desaturation per study was 0.5 (0 to 49), the median oxygen saturation nadir was 91% (50% to 99%), and the median peak end-tidal pCO2 was 47 mm Hg (36 to 87 mm Hg). Forty-two children (47.7%) had abnormal initial study results, usually caused by hypoxemia. Two children with severe obstructive sleep apnea eventually required continuous positive airway pressure therapy, and three additional children required tracheostomies. (1) Children with achondroplasia often have sleep-related respiratory disturbances, primarily hypoxemia. (2) The majority do not have significant obstructive or central apnea; however, a substantial minority are severely affected. (3) Tonsillectomy and adenoidectomy decreases the degree of upper airway obstruction in most but not all children with achondroplasia and obstructive sleep apnea. (4) Restrictive lung disease can present at a young age in children with achondroplasia.

Embedded systems are everywhere, from home appliances to critical systems such as medical devices. They usually have associated timing constraints that need to be verified for the implementation. Here, we use an untimed bounded model... more

Embedded systems are everywhere, from home appliances to critical systems such as medical devices. They usually have associated timing constraints that need to be verified for the implementation. Here, we use an untimed bounded model checker to verify timing properties of embedded C programs. We propose an approach to specify discrete time timing constraints using code annotations. The annotated code is then automatically translated to code that manipulates auxiliary timer variables and is thus suitable as input to conventional, untimed software model checker such as ESBMC. Thus, we can check timing constraints in the same way and at the same time as untimed system requirements, and even allow for interaction between them. We applied the proposed method in a case study, and verified timing constraints of a pulse oximeter, a noninvasive medical device that measures the oxygen saturation of arterial blood.

Pulse oximeters are known to be inaccurate in the presence of elevated concentrations of carboxyhemoglobin and methemoglobin. This paper attempts to alleviate some of the confusion that exists between fractional and functional saturation,... more

Pulse oximeters are known to be inaccurate in the presence of elevated concentrations of carboxyhemoglobin and methemoglobin. This paper attempts to alleviate some of the confusion that exists between fractional and functional saturation, and to clarify the comparison of each with SpO2. A series of theoretical relationships between pulse oximeter reading (SpO2) and actual oxygen saturation (both fractional and functional) is derived using simple absorption theory. The theoretical relationships are checked using an experimental in vitro test system. This consists of a blood circuit containing a model finger, capable of simulating the pulsatile transmission signals through a real finger. Theoretical predictions and experimental results are compared and are found to agree well in the presence of carboxyhemoglobin, but less well with methemoglobin. Possible reasons are discussed.

Abstract—A new method for pulse oximetry is presented that possesses an inherent insensitivity to corruption by motion arti-fact, a primary limitation in the practical accuracy and clinical ap-plicability of current technology. Artifact... more

Abstract—A new method for pulse oximetry is presented that possesses an inherent insensitivity to corruption by motion arti-fact, a primary limitation in the practical accuracy and clinical ap-plicability of current technology. Artifact corruption of the under-lying ...

SUMMARY THE PITFALLS IN THE PRESCRIPTION AND USAGE OF OXYGEN CONCENTRATORS Long-term oxygen therapy (LTOT) increases the quality of life and also decreases morbidity and mortality in chronic res- piratory failure when used sufficient... more

SUMMARY THE PITFALLS IN THE PRESCRIPTION AND USAGE OF OXYGEN CONCENTRATORS Long-term oxygen therapy (LTOT) increases the quality of life and also decreases morbidity and mortality in chronic res- piratory failure when used sufficient time. This study was performed on 20 patients are using oxygen concentrator in Malatya. We visited all patient at home and recorded demographic features, history, physical