In this study, we investigated the effect of time gating threshold on the delivered dose at a organ with internal motion by respiration. Generally, the internal organs have minimum motion at exhalation during normal breathing. Therefore to compare the dose distribution time gating threshold, in this paper, was determined as the moving region of target during 1 sec at the initial position of exhalation. The irradiated fields were then delivered under three conditions; 1) non-moving target 2) existence of the moving target in the region of threshold (1sec), 3) existence of the moving target region out of threshold (1.4 sec, 2 sec). And each of conditions was described by the moving phantom system. It was compared with the dose distributions of three conditions using film dosimetry. Although the treatment time increased when the dose distributions was obtained by the internal motion to consider the TGT, it could be obtained more exact dose distribution than in the treatment field that didn't consider the internal motion. And it could be reduced the unnecessary dose at the penumbra region. When we set up 1.4 sec of threshold, to reduce the treatment time, it could not be obtained less effective dose distribution than 1 sec of threshold. Namely, although the treatment time reduce, the much dose was distributed out of the treatment region. Actually when it is treated the moving organ, it would rather measure internal motion and external motion of the moving organ than mathematical method. If it could be analyzed the correlation of the internal and external motion, the treatment scores would be improved.
Exhalation ; Film Dosimetry ; Respiration*

In this study, we evaluated feasibility of applying MTV (Metabolic Target Volume) to respiratory gated radiotherapy for more accurate treatment using various SUV (Standard Uptake Value) from PET images. We compared VOI (Volume of Interest) images from 50%, 30% and 5% SUV (standard uptake volume) from PET scan of an artificial target with GTV (Gross Tumor Volume) images defined by percentage of respiratory phase from 4D-CT scan for respiratory gated radiotherapy. It is found that the difference of VOI of 30% SUV is reduced noticeably comparing with that of 50% SUV in longitudinal direction with respect to total GTV of 4D-CT image. Difference of VOI of 30% SUV from 4D-PET image defined by respiratory phase from 25% inhalation to 25% exhalation, and GTV from 4D-CT with the same phase is shown below 0.6 cm in maximum. Thus, it is better to use 4D-PET images than conventional PET images for applying MTV to gated RT. From the result that VOI of 5% SUV from 4D-PET agrees well with reference image of 4D-CT in all direction, and the recommendation from department of nuclear medicine that 30% SUV be advised for defining tumor range, it is found that using less than 30% SUV will be more accurate and practical to apply MTV for respiratory gated radiotherapy.
Exhalation ; Inhalation ; Nuclear Medicine ; Positron-Emission Tomography

Exhalation ; Humans ; Nitric Oxide ; analysis ; Nose

During general anesthesia, removal of exhaled carbon dioxide by rebreathing appliances is provided by chemical absorption and this carbon dioxide absorption during anesthesia would at first glance seem to be a simple problem. The problem, however, is far more complicated and much attention must be given to details of rebreathing appliances. Incomplete removal of carbon dioxide in circle absorber systems, which are commonly used today must be carefully monitored to prevent hypercapnea caused by accumulation of carbon dioxide in the breathing circuits. Although circle absorbers have been developed through clinical trials anesthesiologists have no reliable indication of the end point of useful life of the absorbent. This study was undertaken to investigate the useful life of the soda lime used in two type of canisters (type A: canister of anesthesia machine. Quantiflex, USA. 12.9cmX16.6cm, tbye B: canister of anesthesia machine, International 2. U.K., 13.1cmX16.9cm). the effect of flow rate on this useful life and the relations between indicator change and the endpoint of useful life of the soda lime. The control group used a as total flow rate of fresh gases at 2.0 liters per minute and the experimental group used a total flow rate of 4.0 liters per minute. The carbon dioxide concentration of 0.1% at the canister exit was employed as the end point of useful life of the absorbent and the exit carbon dioxide concentration were monitored continuously by intra-red carbon dioxide monitor apparatus(Datex Normocap CD-102, Pinland). Also the carbon dioxide concentration in the respiratory circuit of exhaling side was examined. The results were as follows: 1) In type A, the average useful life of soda lime was 1,885 minutes in the control group and 2,514 minutes in the experimental group. In type B, the average useful life of soda lime was 1,587 minutes in the control group and 1,980 minutes in the experimental group. 2) At the end point of useful life of the absorbent the level of the color change of the indicator of the absorbent in all types was above the three-fourth height of two chambered canister. 3) At the end point, end tidal CO2 concentration was 3.5 vol% in the control group 2.88 vol% in the experimental group. The data obtained from this observation indicated that the increase of total flow rate of gas and the type A canister prolonged the useful life of soda lime and that the double chambered canister could be used safely until the color change of the indicator reached the level of three fourth the height of the canister.
Absorption ; Anesthesia ; Anesthesia, General ; Carbon Dioxide ; Exhalation ; Gases ; Respiration

Breath Tests ; Child, Preschool ; Exhalation ; Humans ; Nitric Oxide ; analysis

Asthma ; diagnosis ; Exhalation ; Humans ; Nitric Oxide ; metabolism ; Respiratory Function Tests

PURPOSE: Few studies have compared fractional exhaled nitric oxide (FeNO) measurement by NIOX VERO® (NOV) and other devices in children. Moreover, there is no agreement between differences in FeNO values obtained using different devices in adults. Here, we compared FeNO values obtained using NOV and NObreath® (NOB) systems to derive a correction equation for children. METHODS: Eighty-eight participants (age 7–15 years) who were diagnosed with atopic bronchial asthma and visited Sagamihara National Hospital as outpatients between January and April of 2017 were included. We measured FeNO values obtained using NOB and NOV, and analyzed them using Wilcoxon tests and Altman-Bland plots. RESULTS: The median age of the participants was 11.5 years, and the scored Asthma Control Test (ACT) or Childhood ACT (C-ACT) was 25 (interquartile range, 24–25) or 26 (24–27). NOB and NOV values were significantly different (31 [14–52] versus 36 [20–59] ppb; P = 0.020) and strongly correlated (r = 0.92). An equation to convert NOB values into NOV values was derived using linear regression as follows: log NOV = 0.7329 × log NOB + 0.4704; NOB for 20, 40, 58, 80 and 100 ppb corresponded to NOV for 27, 44, 59, 73 and 86 ppb. Thus, NOB < 58 ppb suggested NOB < NOV, whereas NOB > 58 ppb suggested NOB > NOV. CONCLUSIONS: NOB and NOV values were strongly correlated. Participants whose FeNO values were relatively low represented NOB < NOV, whereas those whose FeNO values were relatively high represented NOB > NOV.
Adult ; Asthma ; Child* ; Exhalation ; Humans ; Linear Models ; Nitric Oxide* ; Outpatients

Real-time free breathing cardiac cine imaging is a reproducible method with shorter acquisition time and without breath-hold for cardiac magnetic resonance imaging. However, the detection of end-diastole and end-systole frames of real-time free breathing cardiac cine imaging for left ventricle function analysis is commonly completed by visual identification, which is time-consuming and laborious. In order to save processing time, we propose a method for semi-automatic identification of end-diastole and end-systole frames. The method fits respiratory motion signal and acquires the expiration phase, end-diastole and end-systole frames by cross correlation coefficient. The procedure successfully worked on ten healthy volunteers and validated by the analysis of left ventricle function compared to the standard breath-hold steady-state free precession cardiac cine imaging without any significant statistical differences. The results demonstrated that the present method could correctly detect end-diastole and end-systole frames. In the future, this technique may be used for rapid left ventricle function analysis in clinic.
Exhalation ; Heart Ventricles ; pathology ; Humans ; Magnetic Resonance Imaging ; Respiration ; Ventricular Function, Left

In vivo ethane production in rats was used as an index of oxygen toxicity. The rats were allocated to four exposure conditions; hyperbaric oxygenation (HBO=5 ATA, 100% O2), normobaric oxygenation (NBO=1 ATA, 100% O2), hyperbaric aeration (HBA=5 ATA, 21% O2) and normobaric aeration (NBA=1 ATA, 21% O2). After 120 minutes of exposure, the rats exposed to high concentration and/or high pressure oxygen exhaled significantly larger amounts of ethane than those exposed to NBA, and the differences in ethane production between any two groups were statistically significant (p<0.01). This finding supports the hypothesis that hypothesis that hyperoxia increase oxygen free-radicals and the radicals produce ethane as a result of lipid peroxidation. It is notable that the ethane exhalation level of the HBA group was significantly higher than that of the NBO group. This difference could not be accounted for by the alveolar oxygen partial pressure difference between the two groups.
Animals ; Ethane* ; Exhalation* ; Hyperbaric Oxygenation ; Hyperoxia* ; Lipid Peroxidation* ; Oxygen ; Partial Pressure ; Rats

OBJECTIVETo investigate the differential value of inhaled volume and exhaled volume in anesthesia mice, and its effect on the pressure change inside of plethysmograph.

METHODSPressure and temperature in head chamber of double-chamber plethysmograph were tested when mice were placed in the body chamber. The differential values of inhaled volume and exhaled volume of mice were calculated.

RESULTThe baseline pressure in head chamber increased with temperature rising within 12 minutes, then went down though temperature remained high. The inhaled volumes of 8 mice were (0.2842 + or - 0.0173)ml,and the differential value of inhaled volume and exhaled volume was (0.0012 + or - 0.0002)ml.

CONCLUSIONThe inhaled volume is larger than exhaled volume, which makes pressure baseline of plethysmograph decreased. The differential value may be generated from respiratory quotient.

Animals ; Exhalation ; physiology ; Inhalation ; physiology ; Mice ; Plethysmography ; Pressure ; Temperature ; Tidal Volume ; Vital Capacity ; physiology