The main purpose of this paper is to describe the design and development of the near-infrared blood-oxygen monitor which is based on the theory of detecting the blood-oxygen parameters of tissue by near-infrared, and the monitor can detect the blood-oxygen parameters of two sides of the local brain tissue. The monitor uses two wavelength ultra-high light LED as lamp-house, and two sensors detect the light scattered by two sides of the local brain tissue, which make the monitor achieve the function of dual detector. The appearance of the monitor's detector is designed to reduce effectively the noise brought by the background and alleviate the discomfort feelings of the patient. At the same time, this apparatus can monitor continuously the brain blood-oxygen parameters of the patients in real time, and output the curves of the blood-oxygen and oxygen concentration of two sides of brain tissue. At last, the biological model experiments and the tests in clinical setting validate the monitor.
Blood Gas Analysis ; instrumentation ; methods ; Brain ; blood supply ; Humans ; Monitoring, Physiologic ; instrumentation ; Oximetry ; instrumentation ; methods ; Oxygen ; blood ; Spectroscopy, Near-Infrared

simultaneous monitoring of blood flow and changes of concentration of oxyhemoglobin (ΔHbO) in brain is a key important method for the research of cerebrovascular disease. In this study, a new monitoring system, combining laser speckle contrast imaging method and spectral analysis method, was proposed, which could be utilized to measure the cerebral blood flow and ΔHbO on mice during traumatic brain injury. The principle of the present system was studied and the hardware platform of the detection system was built. Then, user interface software and algorithms were implemented based on Labview and Matlab software. Finally, the performance of the present system was verified by the experiments.
Algorithms ; Animals ; Blood Gas Analysis ; instrumentation ; Brain ; Cerebrovascular Circulation ; Lasers ; Mice ; Oxygen ; analysis

This study was undertaken to determine the effect on blood gas determinations of an incomplete purging of the heparinized flush solution from an indwelling arterial catheter and pressure tubing. Arterial blood gases were measured serially after withdrawing 2,4,6,8,10, and 12 ml of flush-blood solution from a 20-gauge radial artery catheter which was connected to one of two kinds of pressure tubing (4-ft and 6-ft Cobe pressure lines). In those samples from the 4-ft Cobe pressure tubing the pH was nearly unchanged in samples 2 thru 6, while the PaCO2, PaO2, actual bicarbonate, and base excess remained approximately constant in samples 3 thru 6. The results of samples taken from the 6-ft tubing were that the pH remained unchanged from samples 3 to 6, and PaCO2, actual bicarbonate, and base excess remained the same from samples 4 onward. PaO2 was unchanged in all sample. In conclusion we suggest that at least 4 ml of blood from a 4-ft Cobe pressure tubing and 6 ml from a 6-ft tubing should be withdrawn prior to arterial blood gas measurements.
Arm/blood supply ; Arteries ; Blood Gas Analysis/instrumentation* ; Catheters, Indwelling* ; Female ; Human ; Male ; Middle Age

This paper is aimed to investigate the signal source and influential factors in signals of trans-esophageal pulse oxygen saturation (SeO2). The red light of the SeO2 probe was faced directly to the descending aorta (DA) of the mongrel dogs. The readings and waveform of SeO2 signals were recorded under following conditions: before and after DA was shield; before and after the blood supply of esophagus was cut off; under the different touch pressures between the SeO2 probe and the esophageal wall. The readings and waveform of SeO2 signals were also recorded respectively at both different esophageal depth and directions when mechanical ventilation was on and off. The tongue oxygen saturation (StO2) was recorded simultaneously as control. The waveform of SeO2 signals disappeared after DA was shield (P < 0.001). No significant difference was found in the SeO2 signals before and after the blood supply of esophagus was cut off (P > 0.05). Compared with the StO2 readings when the SeO2 probe was placed at different esophageal depth, the waldeyer ring, cervical area and thoracic inlet,the readings of SeOz significantly decreased (P < 0.05) while mechanical ventilation was on and off. However, there was no significant difference in the readings between SeO2 signals from DA, aortic arch (AA) and left subclavian artery and the StO2 signals recorded simultaneously. Mechanical ventilation had a remarkable effect on the SeO2 signals at different esophageal depth (P < 0.05), but the StO2 signals lay in its insensitivity to its influence. The readings of StO2 signals were significantly different from that of StO2 signals when the touch pressure between the SeO2 probe and the esophageal wall below 40 mmHg (P < 0.01). The directions of the optimum SeO2 signals acquired at different esophageal depth were not the same. The SeO2 signals were primarily derived from deeper arteries around the esophagus. All of Mechanical ventilation, location of the SeO2 probe in the esophagus and the touch pressure between the probe and esophageal wall can influence SeO2 signals.
Animals ; Aorta, Thoracic ; physiology ; Biosensing Techniques ; instrumentation ; methods ; Blood Gas Analysis ; instrumentation ; methods ; Dogs ; Esophagus ; blood supply ; Female ; Male ; Oximetry ; instrumentation ; methods ; Oxygen ; blood ; Signal Processing, Computer-Assisted

OBJECTIVETo compare the effectiveness of high-frequency jet ventilation via Wei jet nasal airway and controlled ventilation with improved laryngeal mask airway during bronchial thermoplasty.

METHODSTwenty-eight patients undergoing bronchial thermoplasty were equally divided into two groups: group A (high-frequency jet ventilation through Wei jet nasal airway) and group B (controlled ventilation with improved laryngeal mask airway). Pulse oxygenation,heart rate,and mean arterial blood pressure were recorded after entering the operating room (T0), 1 minute after administration/induction (T1), bronchoscope inserting (T2), 15 minutes (T3)/30 minutes (T4)/45 minutes (T5) after ventilation,at the end of the operation (T6), and at the recovery of patients' consciousness (T7). The pH,arterial oxygen partial pressure,and arterial carbon dioxide partial pressure were recorded at T0, T4, and T6. The endoscope indwelling duration,operative time,patients' awakening time,adverse events during anesthesia,satisfactions of patients and operators, anesthesic effectiveness were also recorded.

RESULTSThe arterial carbon dioxide partial pressur in group A at T4 and T6 were significantly higher than in group B (P<0.05). The pH in group A at T4 and T6 was significantly lower than in group B (P<0.05). The endoscope indwelling duration and the operative time in group B were significantly shorter than in group A (P<0.05) while the recovery of consciousness in group B was significantly longer than in group A (P<0.05). The satisfaction for operators and the efficacy of anesthesia in group B were better than in group A (P<0.05). The number of adverse events in group B was significantly smaller than in group A (P<0.05).

CONCLUSIONThe improved laryngeal mask airway with controlled ventilation is more suitable for bronchial thermoplasty.

Blood Gas Analysis ; Bronchoscopy ; Catheter Ablation ; Heart Rate ; High-Frequency Jet Ventilation ; instrumentation ; Humans ; Laryngeal Masks

Blood Gas Analysis ; Continuous Positive Airway Pressure ; instrumentation ; Humans ; Infant ; Infant, Newborn ; Pneumonia ; blood ; physiopathology ; therapy ; Respiration

It is the intent of this study to simulate the performance of trans-esophageal aortic blood oxygen saturation (SeO2) monitoring by using trans-esophageal echocardiography (TEE) probe to provide an evidence for proper positioning of placing SeO2 sensor. 25 selected cardiac surgical patients were involved. After anesthesia was induced and trachea was intubated, the multiplane TEE probe was inserted into the esophagus, and the depths from the fore-tooth to the location for detecting aorta were recorded when the distances between TEE probe and aorta anterior wall were shorter than 0.5 cm, 1 cm, and longer than 1 cm, respectively. The o'clock directions of TEE probe were also recorded. The multiplane TEE probe, with its one-use pediatric SpO2 sensor attached, was inserted, and its anterior structure was examined when trans-esophagus oximetry detected high quality SpO2 signals. The results showed the beginning position of detecting aortic SpO2 signal in esophagus was mid esophagus (24.8 +/- 4.4 cm from the fore-teeth), the moving range was 5-10 cm downward, the deepest depth of detecting descending aorta was 41.4 +/- 4.7 cm from the fore-tooth, and the direction was left-posterior. And photoplethymography (PPG) wave's form was changed when SpO2 probe's anterior structure was different.
Adolescent ; Adult ; Aorta ; physiology ; Blood Gas Analysis ; instrumentation ; methods ; Echocardiography, Transesophageal ; Female ; Humans ; Male ; Middle Aged ; Monitoring, Physiologic ; methods ; Oximetry ; methods ; Oxygen ; blood ; Pilot Projects ; Young Adult

OBJECTIVETo compare the differences in intrapulmonary shunt (Qs/Qt) and arterial oxygenation between selective left lower lobar blockade by Coopdech endobronchial blocker tubes (BB) and one lung ventilation (OLV) by left-sided double-lumen endobronchial tubes (DLT) in patients with normal pulmonary function.

METHODSThirty-six patients (aged 32-64 years) scheduled for lower esophageal surgery were allocated randomly into BB and DLT groups (n=18). Anesthesia was induced and maintained with Propofol by target controlled infusion with intravenous administration of sufentanil and cisatracurium if needed. A 35 to 39 French tube was placed in the DLT group, and an 8.0-mm (internal diameter) single-lumen endotracheal tube was used in the BB group where a 9 French Coopdech BB was advanced into the left lower lobar bronchus guided by a fiberoptic bronchoscope. The variables recorded were blood gas analysis data from the venous and arterial blood samples at 20 min after two-lung ventilation in supine position (T(1)), 20 min after initiation of one-lung ventilation or selective left lower lobar blockade by inflating BB balloons in the right lateral decubitus position (T(2)), total collapse of the left lung or the left lower lobe after the pleura was opened (T(3)), and before tracheal extubation (T(4)). Qs/Qt was calculated using a standard formula based on the three-compartment model. Upon pleura opening, the effectiveness of lung collapse was evaluated by the surgeon who performed the surgery. Chest radiograph and arterial blood gas analyses were performed the day after the operation.

RESULTSBoth of the groups were similar with regard to rank of the surgical exposure, pH, PaCO(2), hemoglobin from T(1) to T(4), Qs/Qt, PaO(2), PO(2), and oxygenation index at T1. In BB group, a significant reduction of Qs/Qt and greater improvements in PaO(2), PO(2), oxygenation index at T(2), T(3) and T(4) were observed in comparison with those in DLT group (P<0.05 or <0.01). No lobe collapse was observed postoperatively in BB group, but 2 patients in DLT group showed left lower lobe atelectasis. The patients in BB group showed better postoperative arterial oxygenation and shorter postoperative hospital stay (P<0.01).

CONCLUSIONSelective left lower lobar blockade by Coopdech endobronchial blocker tube during lower esophageal surgery provides a lower intraoperative intrapulmonary shunt and a better intra- and postoperative arterial oxygenation..

Adult ; Blood Gas Analysis ; Bronchoscopes ; Continuous Positive Airway Pressure ; instrumentation ; methods ; Esophageal Neoplasms ; surgery ; Female ; Fiber Optic Technology ; Humans ; Intubation, Intratracheal ; methods ; Lung ; physiology ; Male ; Middle Aged ; Oxygen ; administration & dosage ; blood ; pharmacology ; Pulmonary Ventilation ; Thoracic Surgical Procedures ; methods

OBJECTIVETo study correlation of brain hypoxia of different degrees with brain function and damage.

METHODSThe brain regional oxygen saturation (rSO2) was determined by using a non-invasive near infrared spectroscopy (NIRS) technique in 15 piglets; the piglets were subjected to inhale 3% - 11% oxygen-nitrogen mixed gas through mechanical ventilation for 30 min. The piglets were divided into groups according to the level of brain rSO2 (i.e. < 30%, 30% - 35%, 35% - 40%, and 40% - 50%), and the data were compared with those of the control group (rSO2 > 60%). Changes of brain function were detected through amplitude and frequency of EEG waves and signal complexity. The piglets were sacrificed via decapitation 72 h after brain damage, and then histopathological and ultrastructural examinations were performed on cerebral cortex and hippocampal CA1 area.

RESULTSIn the group with rSO2 > 40%, the mean arterial pressure (MAP) after hypoxia was (56 +/- 0.00) mm Hg (1 mm Hg = 0.133 kPa), the blood lactic acid (LA) was (2.3 +/- 1.2) mmol/L, the EEG findings were within normal range, and there was no change in brain tissue ultrastructure. In the group with brain rSO2 = 30% approximately 40%, the MAP was (73 +/- 8) mm Hg, the LA was (8.2 +/- 3.9) mmol/L, the EEG waves showed decreased amplitude, frequency and complexity, but restored to some extent after hypoxia. The brain tissue ultrastructure showed damages to the cerebral cortex and neuron mitochondria at hippocampal CA1 area. In the group with brain rSO2 < 30%, the MAP was (35 +/- 0) mm Hg, the LA was (12 +/- 2) mmol/L, the EEG showed decreased amplitude, frequency, and complexity of signals compared with those of the normal control group, and was difficult to restore after hypoxia in some of the piglets; the brain tissue ultrastructure appeared to be similar to the changes seen with high-degree swollen cerebral cortex and neuron mitochondria at hippocampal CA1 area.

CONCLUSIONDifferent degrees of hypoxia had different influence on brain function and brain damage. The lower the brain rSO2, the more severe the damages to the brain and its function. The rSO2 of brain tissues detected with noninvasive NIRS can reflect brain injury and its severity during cerebral anoxia.

Animals ; Blood Gas Analysis ; Brain Injuries ; complications ; Cerebral Cortex ; physiopathology ; Cerebrovascular Circulation ; physiology ; Electroencephalography ; Female ; Hypoxia ; metabolism ; pathology ; Hypoxia, Brain ; complications ; Hypoxia-Ischemia, Brain ; physiopathology ; Male ; Neurons ; pathology ; Oximetry ; instrumentation ; Oxygen ; metabolism ; Oxygen Consumption ; Spectroscopy, Near-Infrared ; methods ; Statistics as Topic ; Swine