Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone Camera
A smartphone-based tidal volume (VT) estimator was recently introduced by our research group, where an Android application provides a chest movement signal whose peak-to-peak amplitude is highly correlated with reference VT measured by a spirometer. We found a Normalized Root Mean Squared Error (NRM...
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MDPI AG
2016-03-01
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| Series: | Sensors |
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| Online Access: | http://www.mdpi.com/1424-8220/16/3/397 |
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| author | Bersain A. Reyes Natasa Reljin Youngsun Kong Yunyoung Nam Sangho Ha Ki H. Chon |
| author_facet | Bersain A. Reyes Natasa Reljin Youngsun Kong Yunyoung Nam Sangho Ha Ki H. Chon |
| author_sort | Bersain A. Reyes |
| collection | DOAJ |
| description | A smartphone-based tidal volume (VT) estimator was recently introduced by our research group, where an Android application provides a chest movement signal whose peak-to-peak amplitude is highly correlated with reference VT measured by a spirometer. We found a Normalized Root Mean Squared Error (NRMSE) of 14.998% ± 5.171% (mean ± SD) when the smartphone measures were calibrated using spirometer data. However, the availability of a spirometer device for calibration is not realistic outside clinical or research environments. In order to be used by the general population on a daily basis, a simple calibration procedure not relying on specialized devices is required. In this study, we propose taking advantage of the linear correlation between smartphone measurements and VT to obtain a calibration model using information computed while the subject breathes through a commercially-available incentive spirometer (IS). Experiments were performed on twelve (N = 12) healthy subjects. In addition to corroborating findings from our previous study using a spirometer for calibration, we found that the calibration procedure using an IS resulted in a fixed bias of −0.051 L and a RMSE of 0.189 ± 0.074 L corresponding to 18.559% ± 6.579% when normalized. Although it has a small underestimation and slightly increased error, the proposed calibration procedure using an IS has the advantages of being simple, fast, and affordable. This study supports the feasibility of developing a portable smartphone-based breathing status monitor that provides information about breathing depth, in addition to the more commonly estimated respiratory rate, on a daily basis. |
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| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-14T06:33:13Z |
| publishDate | 2016-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-15fa6f868d1d456e901d461361f145e92022-12-22T02:07:32ZengMDPI AGSensors1424-82202016-03-0116339710.3390/s16030397s16030397Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone CameraBersain A. Reyes0Natasa Reljin1Youngsun Kong2Yunyoung Nam3Sangho Ha4Ki H. Chon5Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USADepartment of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USADepartment of Computer Science and Engineering, Soonchunhyang University, Asan 336-745, KoreaDepartment of Computer Science and Engineering, Soonchunhyang University, Asan 336-745, KoreaDepartment of Computer Science and Engineering, Soonchunhyang University, Asan 336-745, KoreaDepartment of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USAA smartphone-based tidal volume (VT) estimator was recently introduced by our research group, where an Android application provides a chest movement signal whose peak-to-peak amplitude is highly correlated with reference VT measured by a spirometer. We found a Normalized Root Mean Squared Error (NRMSE) of 14.998% ± 5.171% (mean ± SD) when the smartphone measures were calibrated using spirometer data. However, the availability of a spirometer device for calibration is not realistic outside clinical or research environments. In order to be used by the general population on a daily basis, a simple calibration procedure not relying on specialized devices is required. In this study, we propose taking advantage of the linear correlation between smartphone measurements and VT to obtain a calibration model using information computed while the subject breathes through a commercially-available incentive spirometer (IS). Experiments were performed on twelve (N = 12) healthy subjects. In addition to corroborating findings from our previous study using a spirometer for calibration, we found that the calibration procedure using an IS resulted in a fixed bias of −0.051 L and a RMSE of 0.189 ± 0.074 L corresponding to 18.559% ± 6.579% when normalized. Although it has a small underestimation and slightly increased error, the proposed calibration procedure using an IS has the advantages of being simple, fast, and affordable. This study supports the feasibility of developing a portable smartphone-based breathing status monitor that provides information about breathing depth, in addition to the more commonly estimated respiratory rate, on a daily basis.http://www.mdpi.com/1424-8220/16/3/397tidal volumeincentive spirometersmartphone cameracalibrationbreathing monitor |
| spellingShingle | Bersain A. Reyes Natasa Reljin Youngsun Kong Yunyoung Nam Sangho Ha Ki H. Chon Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone Camera Sensors tidal volume incentive spirometer smartphone camera calibration breathing monitor |
| title | Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone Camera |
| title_full | Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone Camera |
| title_fullStr | Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone Camera |
| title_full_unstemmed | Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone Camera |
| title_short | Employing an Incentive Spirometer to Calibrate Tidal Volumes Estimated from a Smartphone Camera |
| title_sort | employing an incentive spirometer to calibrate tidal volumes estimated from a smartphone camera |
| topic | tidal volume incentive spirometer smartphone camera calibration breathing monitor |
| url | http://www.mdpi.com/1424-8220/16/3/397 |
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