Category Archives: BTPS Correction

BTPS Correction for Ceramic Flow Sensor: Recommendations

BTPS Correction for Ceramic Flow Sensor: RecommendationsOne study has reported it to be closer to 34°C and we have measured approximately 35.5°C. In addition, the subject’s exhaled air contains approximately 5 percent CO2 that was not present in our experiments using the mechanical simulator, filled with air from the room.
Another possible explanation for the maneuver order effect is the subjects may be exhibiting a learning effect or somehow varying their efforts in this uncoached environment, thereby increasing their values with each successive maneuver canadianneighborpharmacy.com. However, feedback based on peak flow was provided to the subject after each maneuver to encourage a maximal effort.
Continue reading

BTPS Correction for Ceramic Flow Sensor: Conclusion

With FVCs of 5 to 6 L and with an initial sensor temperature of 20°C, the heat transfer after two consecutive trials is sufficient to raise the surface temperature of the sensor to a level at which little additional heat transfer occurs. This heat slowly dissipates with time, with the sensor returning to ambient temperature within approximately 20 min. The fact that the sensor temperature rapidly rises with each successive FVC maneuver probably explains why water condensation has not affected test results.
Continue reading

BTPS Correction for Ceramic Flow Sensor: Discussion

BTPS Correction for Ceramic Flow Sensor: DiscussionThe percent difference in FEVi, obtained using room vs heated-humidified air (proportional to the magnitude of BTPS correction factor needed), ranged from 0.3 percent to 6.2 percent and varied with the number of maneuvers previously performed, the time interval between maneuvers, the volume of the current and previous maneuvers, and the starting temperature of the sensor there health and care mall. Correspondingly, the temperature of the air leaving the sensor (exit) temperature) showed a steady rise with each successive maneuver using heated air. When six subjects performed repeated tests over several days, a maneuver order effect was observed similar to the results obtained using the mechanical pump.
Continue reading

BTPS Correction for Ceramic Flow Sensor: Experiments

Figure 5 shows the relationship of the percent difference in FEVi between room air and heated-humidified air vs the exit air temperature at 1 s using data from experiments 1 through 4. A least squares linear fit to these data is shown in the figure and the correlation coefficient was 0.91. Since there were only a few data points at the lowest temperatures, a second linear fit was made using only data with temperatures greater than 20°C. The correlation coefficient in this analysis was only reduced to 0.89. If the relationship shown in Figure 5 is used to derive a dynamic BTPS correction factor, then the equivalent FEVi accuracy would be within ±2 percent when a dynamic BTPS correction factor is used. Similar results were obtained for FEV05.
Continue reading

BTPS Correction for Ceramic Flow Sensor: Results

BTPS Correction for Ceramic Flow Sensor: ResultsFigure 3 shows the results for experiment 1 or the percent difference between room air and air heated-humidified for FEVi vs the order in which the maneuvers were performed. The ten consecutive FVC maneuvers for each ATS waveform are connected by a line. For each successive FVC maneuver, the percent difference between room and heated air decreases, particularly for waveforms with larger volumes (ATS waveforms 1 and 2) read more buy birth control. Lower percent differences between room and heated air correspond to a smaller BTPS correction factor being required for BTPS correction. Note that for wave form 4 (FVC=1.5L), the magnitude of the percent difference remains greater than approximately 2 percent even after ten consecutive maneuvers have been performed.
Continue reading

BTPS Correction for Ceramic Flow Sensor: Actually the Result

These subjects were part of an indoor air quality investigation and were performing repeated spirometry to assess changes in pulmonary function over the day and week—both at and away from work. To reduce fatigue and obtain better subject compliance with the testing protocol, the subjects were told they could terminate forced exhalation when the instrument beeped at 6 s after the onset of flow. Although the flow spirometer continued to collect data for up to 9 s, the resulting FVCs are actually the result of the subjects terminating their maneuvers after approximately 6 s of exhalation. To compare results using the volume spirometer with those using the flow spirometer, only the first three FVC maneuvers obtained on the volume spirometer were used. In addition, some comparisons were made using the FEV6, since the exhalation times were limited to 6 to 9 s when using the flow spirometer. Viagra super active plus Source A dynamic BTPS correction factor previously described was used to correct the FEVb FEVg, and FVC obtained from the flow spirometer, the dynamic BTPS correction factor developed in this study was used.
Continue reading

BTPS Correction for Ceramic Flow Sensor: Ceramic Element

BTPS Correction for Ceramic Flow Sensor: Ceramic ElementIn experiment 2, the time between successive maneuvers was varied (<1 min, 2 min, 5 min, 10 min, 15 min, and 20 min). The first ATS standard waveform was forced through the sensors, but five consecutive repeats, instead of ten (as in experiment 1), were conducted. This experiment was repeated on four different flow sensors and results were averaged for the four sensors Here canadian health and care mall. In both experiments 1 and 2, the flow sensors were flushed with room air and allowed to cool to ambient temperature before repeating the ten (five) consecutive maneuvers.
Continue reading

BTPS Correction for Ceramic Flow Sensor: Methods

To investigate BTPS correction, five different experiments were conducted. Both the flow sensors and associated electronics were purchased (Tamarac Systems, Denver) and used with data acquisition software written specifically for our particular experiments. To calibrate the ceramic spirometry system, five runs of 30 different constant flows (6 L of volume injected at a constant flow) from 0.4 to 12 L/s were injected through each of the flow sensors (150 flow tests for each sensor). The resulting flows were measured and a calibration equation for flow was determined by using a quadratic function least squares fit to the 30 flow values. http://asthma-inhalers-online.com itat on Volume was determined by integrating the calibrated flow signal.
Continue reading

BTPS Correction for Ceramic Flow Sensor

BTPS Correction for Ceramic Flow SensorThere are essentially two types of spirometers: those measuring volume directly and those measuring and integrating flow to determine volume of air. The flow type spirometer, because of its small size, is particularly well suited in situations where portability is important. An unheated ceramic flow sensor, one type of flow sensor frequently used to determine flow and calculate expiratory volume, is particularly well suited for use in battery-operated spirometers. These ceramic flow sensors do not need to be heated-a process that consumes considerable battery power read more . As they become available, these portable devices will likely have wide clinical application in the assessment of asthma, providing much useful information in addition to peak expiratory flow (eg, flow-volume curves and FEVis). Continue reading