{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T17:29:10Z","timestamp":1773422950021,"version":"3.50.1"},"reference-count":101,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2021,6,9]],"date-time":"2021-06-09T00:00:00Z","timestamp":1623196800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In the last few decades, a number of wearable systems for respiration monitoring that help to significantly reduce patients\u2019 discomfort and improve the reliability of measurements have been presented. A recent research trend in biosignal acquisition is focusing on the development of monolithic sensors for monitoring multiple vital signs, which could improve the simultaneous recording of different physiological data. This study presents a performance analysis of respiration monitoring performed via forcecardiography (FCG) sensors, as compared to ECG-derived respiration (EDR) and electroresistive respiration band (ERB), which was assumed as the reference. FCG is a novel technique that records the cardiac-induced vibrations of the chest wall via specific force sensors, which provide seismocardiogram-like information, along with a novel component that seems to be related to the ventricular volume variations. Simultaneous acquisitions were obtained from seven healthy subjects at rest, during both quiet breathing and forced respiration at higher and lower rates. The raw FCG sensor signals featured a large, low-frequency, respiratory component (R-FCG), in addition to the common FCG signal. Statistical analyses of R-FCG, EDR and ERB signals showed that FCG sensors ensure a more sensitive and precise detection of respiratory acts than EDR (sensitivity: 100% vs. 95.8%, positive predictive value: 98.9% vs. 92.5%), as well as a superior accuracy and precision in interbreath interval measurement (linear regression slopes and intercepts: 0.99, 0.026 s (R2 = 0.98) vs. 0.98, 0.11 s (R2 = 0.88), Bland\u2013Altman limits of agreement: \u00b10.61 s vs. \u00b11.5 s). This study represents a first proof of concept for the simultaneous recording of respiration signals and forcecardiograms with a single, local, small, unobtrusive, cheap sensor. This would extend the scope of FCG to monitoring multiple vital signs, as well as to the analysis of cardiorespiratory interactions, also paving the way for the continuous, long-term monitoring of patients with heart and pulmonary diseases.<\/jats:p>","DOI":"10.3390\/s21123996","type":"journal-article","created":{"date-parts":[[2021,6,9]],"date-time":"2021-06-09T14:16:04Z","timestamp":1623248164000},"page":"3996","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":48,"title":["Respiration Monitoring via Forcecardiography Sensors"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4829-3941","authenticated-orcid":false,"given":"Emilio","family":"Andreozzi","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering and Information Technologies, University of Naples Federico II, Via Claudio, 21, 80125 Napoli, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3422-8727","authenticated-orcid":false,"given":"Jessica","family":"Centracchio","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering and Information Technologies, University of Naples Federico II, Via Claudio, 21, 80125 Napoli, Italy"}]},{"given":"Vincenzo","family":"Punzo","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering and Information Technologies, University of Naples Federico II, Via Claudio, 21, 80125 Napoli, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0716-8431","authenticated-orcid":false,"given":"Daniele","family":"Esposito","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering and Information Technologies, University of Naples Federico II, Via Claudio, 21, 80125 Napoli, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1918-0393","authenticated-orcid":false,"given":"Caitlin","family":"Polley","sequence":"additional","affiliation":[{"name":"School of Engineering, Design and Built Environment, Western Sydney University, Penrith, NSW 2751, Australia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2616-2804","authenticated-orcid":false,"given":"Gaetano D.","family":"Gargiulo","sequence":"additional","affiliation":[{"name":"School of Engineering, Design and Built Environment, Western Sydney University, Penrith, NSW 2751, Australia"},{"name":"The MARCS Institute, Western Sydney University, Penrith, NSW 2751, Australia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9585-971X","authenticated-orcid":false,"given":"Paolo","family":"Bifulco","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering and Information Technologies, University of Naples Federico II, Via Claudio, 21, 80125 Napoli, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2021,6,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1007\/BF02348078","article-title":"Critical review of non-invasive respiratory monitoring in medical care","volume":"41","author":"Folke","year":"2003","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1002\/ppul.21416","article-title":"Respiration Rate Monitoring Methods: A Review","volume":"46","author":"Saatchi","year":"2011","journal-title":"Pediatric Pulmonol."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Cesareo, A., Previtali, Y., Biffi, E., and Aliverti, A. (2019). Assessment of Breathing Parameters Using an Inertial Measurement Unit (IMU)-Based System. Sensors, 19.","DOI":"10.3390\/s19010088"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1038\/s41746-019-0083-3","article-title":"Respiration rate and volume measurements using wearable strain sensors","volume":"2","author":"Chu","year":"2019","journal-title":"NPJ Digit. Med."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Massaroni, C., Nicol\u00f2, A., Lo Presti, D., Sacchetti, M., Silvestri, S., and Schena, E. (2019). Contact-Based Methods for Measuring Respiratory Rate. Sensors, 19.","DOI":"10.3390\/s19040908"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/TBME.2007.910679","article-title":"Breathing Detection: Towards a Miniaturized, Wearable, Battery-Operated Monitoring System","volume":"55","author":"Corbishley","year":"2008","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"635","DOI":"10.3389\/fphys.2020.00635","article-title":"Remote Respiratory Monitoring in the Time of COVID-19","volume":"11","author":"Massaroni","year":"2020","journal-title":"Front. Physiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"07TR01","DOI":"10.1088\/1361-6579\/ab299e","article-title":"Recent development of respiratory rate measurement technologies","volume":"40","author":"Liu","year":"2019","journal-title":"Physiol. Meas."},{"key":"ref_9","first-page":"113","article-title":"Flowmeter for recording respiratory flow of human subjects","volume":"2","author":"Lilly","year":"1950","journal-title":"Method. Med. Res."},{"key":"ref_10","unstructured":"Miller, R.W. (1983). Flow Measurement Engineering Handbook, McGraw-Hill."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"752540","DOI":"10.1155\/2015\/752540","article-title":"Experimental assessment of a variable orifice flowmeter for respiratory monitoring","volume":"2015","author":"Tardi","year":"2015","journal-title":"J. Sens."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1152\/jappl.1975.38.2.360","article-title":"A bidirectional respiratory flowmeter using the hot-wire principle","volume":"38","author":"Yoshiya","year":"1975","journal-title":"J. Appl. Physiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1016\/j.measurement.2005.07.005","article-title":"Novel target type flowmeter based on a differential fiber Bragg grating sensor","volume":"38","author":"Zhao","year":"2005","journal-title":"Measurement"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"125302","DOI":"10.1088\/0957-0233\/19\/12\/125302","article-title":"Fiber Bragg grating sensor for simultaneous measurement of flow rate and direction","volume":"19","author":"Lu","year":"2008","journal-title":"Meas. Sci. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1952","DOI":"10.1109\/JSEN.2009.2031845","article-title":"A simple fiber-optic flowmeter based on bending loss","volume":"9","author":"Hu","year":"2009","journal-title":"IEEE Sens. J."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Li, S.H., Lin, B.S., Tsai, C.H., Yang, C.T., and Lin, B.S. (2017). Design of wearable breathing sound monitoring system for real-time wheeze detection. Sensors, 17.","DOI":"10.3390\/s17010171"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/978-3-031-01617-2","article-title":"Fundamentals of respiratory sounds and analysis","volume":"1","author":"Moussavi","year":"2006","journal-title":"Synth. Lect. Biomed. Eng."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"13830","DOI":"10.3390\/s140813830","article-title":"Tracheal sounds acquisition using smartphones","volume":"14","author":"Reyes","year":"2014","journal-title":"Sensors"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Sierra, G., Telfort, V., Popov, B., Pelletier, M., Despault, P., Lanzo, V., and Agarwal, R. (2006, January 17\u201318). Comparison of respiratory rate estimation based on tracheal sounds versus a capnograph. Proceedings of the 27th Annual International Conference of the Engineering in Medicine and Biology Society (IEEE-EMBS 2005), Shanghai, China.","DOI":"10.1109\/IEMBS.2005.1615897"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Wang, Y.D., Liu, C.H., Jiang, R.Y., and Lin, B.S. (2017). Novel Approach of Respiratory Sound Monitoring under Motion. International Conference on Intelligent Information Hiding and Multimedia Signal Processing, Springer.","DOI":"10.1007\/978-3-319-63856-0_21"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1016\/0250-6874(86)80053-1","article-title":"Thermal sensors based on the seebeck effect","volume":"10","author":"Sarro","year":"1986","journal-title":"Sens. Actuators"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1007\/BF01617716","article-title":"Measurement of respiratory rate and timing using a nasal thermocouple","volume":"11","author":"Marks","year":"1995","journal-title":"J. Clin. Monit."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1187","DOI":"10.1109\/10.544342","article-title":"Heat transfer evaluation of the nasal thermistor technique","volume":"43","author":"Storck","year":"1996","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Kwon, K.T., Lim, S., Kwon, S.I., Kim, C.M., Park, S.H., Shin, S.S., Lee, S., Ahn, S.D., Kim, J.H., and Choi, E.K. (2007). Comparison of thermocouple, spirometer and skin motion for respiratory target motion measurement. World Congress on Medical Physics and Biomedical Engineering 2006, Springer.","DOI":"10.1007\/978-3-540-36841-0_494"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1088\/0950-7671\/39\/9\/308","article-title":"A fast-response pyroelectric thermal detector","volume":"39","author":"Cooper","year":"1962","journal-title":"J. Sci. Instrum."},{"key":"ref_26","unstructured":"Huang, Y.P., and Huang, K.N. (2013, January 12\u201316). Monitoring of breathing rate by a piezofilm sensor using pyroelectric effect. Proceedings of the 2013 International Conference on Orange Technologies (ICOT), Tainan, Taiwan."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"526","DOI":"10.1109\/LED.2004.832657","article-title":"A rapid-response, high-sensitivity nanophase humidity sensor for respiratory monitoring","volume":"25","author":"Kalkan","year":"2004","journal-title":"IEEE Electron. Device. Lett."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Gaspar, C., Olkkonen, J., Passoja, S., and Smolander, M. (2017). Paper as active layer in inkjet-printed capacitive humidity sensors. Sensors, 17.","DOI":"10.3390\/s17071464"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2125","DOI":"10.1109\/JSEN.2017.2787556","article-title":"Fiber Bragg Grating Probe for Relative Humidity and Respiratory Frequency Estimation: Assessment During Mechanical Ventilation","volume":"18","author":"Massaroni","year":"2018","journal-title":"IEEE Sens. J."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1508","DOI":"10.3390\/s8031508","article-title":"Synthesis and characterization of carbon nitride films for micro humidity sensors","volume":"8","author":"Lee","year":"2008","journal-title":"Sensors"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Scholz, R., Bracio, B.R., Brutscheck, M., and Trommler, P. (2017, January 20\u201321). Non-invasive respiratory rate detection in spontaneous respiration by humidity measurement. Proceedings of the 2017 28th Irish Signals and Systems Conference (ISSC), Killarney, Ireland.","DOI":"10.1109\/ISSC.2017.7983620"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/LSENS.2017.2787099","article-title":"Silica Nanoparticle-Based Portable Respiration Sensor for Analysis of Respiration Rate, Pattern, and Phase during Exercise","volume":"2","author":"Kano","year":"2018","journal-title":"IEEE Sens. Lett."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Ascorbe, J., Corres, J., Arregui, F., and Matias, I. (2017). Recent Developments in Fiber Optics Humidity Sensors. Sensors, 17.","DOI":"10.3390\/s17040893"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2615","DOI":"10.1109\/JSEN.2014.2312353","article-title":"Highly sensitive carbon nanotubes coated etched fiber bragg grating sensor for humidity sensing","volume":"14","author":"Shivananju","year":"2014","journal-title":"IEEE Sens. J."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Wu, C.W., and Chiang, C.C. (2016). Sandwiched long-period fiber grating fabricated by MEMS process for CO2 gas detection. Micromachines, 7.","DOI":"10.3390\/mi7030035"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"026003","DOI":"10.1088\/1752-7163\/aa8dbd","article-title":"Real-time human respiration carbon dioxide measurement device for cardiorespiratory assessment","volume":"12","author":"Singh","year":"2018","journal-title":"J. Breath Res."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Katagiri, T., Shibayama, K., Iida, T., and Matsuura, Y. (2018). Infrared Hollow Optical Fiber Probe for Localized Carbon Dioxide Measurement in Respiratory Tracts. Sensors, 18.","DOI":"10.3390\/s18040995"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"19618","DOI":"10.3390\/s150819618","article-title":"A low-power and portable biomedical device for respiratory monitoring with a stable power source","volume":"15","author":"Yang","year":"2015","journal-title":"Sensors"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.sna.2018.07.006","article-title":"Theory, technology and applications of piezoresistive sensors: A review","volume":"281","author":"Fiorillo","year":"2018","journal-title":"Sens. Actuators A Phys."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1109\/JSEN.2014.2339739","article-title":"Weft-knitted strain sensor for monitoring respiratory rate and its electro-mechanical modeling","volume":"15","author":"Atalay","year":"2015","journal-title":"IEEE Sens. J."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1109\/TITB.2009.2037614","article-title":"Comparative evaluation of susceptibility to motion artifact in different wearable systems for monitoring respiratory rate","volume":"14","author":"Scilingo","year":"2010","journal-title":"IEEE Trans. Inf. Technol. Biomed."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Jeong, J., Jang, Y., Lee, I., Shin, S., and Kim, S. (2009, January 7\u201312). Wearable respiratory rate monitoring using piezo-resistive fabric sensor. Proceedings of the World Congress on Medical Physics and Biomedical Engineering, Munich, Germany.","DOI":"10.1007\/978-3-642-03904-1_78"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Molinaro, N., Massaroni, C., Lo Presti, D., Saccomandi, P., Di Tomaso, G., Zollo, L., Perego, P., Andreoni, G., and Schena, E. (2018, January 18\u201321). Wearable textile based on silver plated knitted sensor for respiratory rate monitoring. Proceedings of the 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Honolulu, HI, USA.","DOI":"10.1109\/EMBC.2018.8512958"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"04CL05","DOI":"10.7567\/JJAP.52.04CL05","article-title":"A wearable capacitive sensor for monitoring human respiratory rate","volume":"52","author":"Kundu","year":"2013","journal-title":"Jpn. J. Appl. Phys."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Grlica, J., Martinovi\u00b4c, T., and D\u017eapo, H. (2015, January 13\u201315). Capacitive sensor for respiration monitoring. Proceedings of the 2015 IEEE Sensors Applications Symposium (SAS), Zadar, Croatia.","DOI":"10.1109\/SAS.2015.7133567"},{"key":"ref_46","first-page":"2695","article-title":"Non-contacting monitoring of respiration and pulse based on capacitive coupling with thoracic tissue","volume":"3","author":"Teichmann","year":"2011","journal-title":"Proc. World Congr. Eng."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Naranjo-Hern\u00e1ndez, D., Talaminos-Barroso, A., Reina-Tosina, J., Roa, L., Barbarov-Rostan, G., Cejudo-Ramos, P., M\u00e1rquez-Mart\u00edn, E., and Ortega-Ruiz, F. (2018). Smart Vest for Respiratory Rate Monitoring of COPD Patients Based on Non-Contact Capacitive Sensing. Sensors, 18.","DOI":"10.3390\/s18072144"},{"key":"ref_48","unstructured":"Reinvuo, T., Hannula, M., Sorvoja, H., Alasaarela, E., and Myllyla, R. (2006, January 7\u20139). Measurement of respiratory rate with high-resolution accelerometer and EMFit pressure sensor. Proceedings of the 2006 IEEE Sensors Applications Symposium, Houston, TX, USA."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1643","DOI":"10.1088\/0967-3334\/33\/10\/1643","article-title":"Extracting respiratory information from seismocardiogram signals acquired on the chest using a miniature accelerometer","volume":"33","author":"Pandia","year":"2012","journal-title":"Physiol. Meas."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"334","DOI":"10.5370\/JEET.2014.9.1.334","article-title":"Improvement of dynamic respiration monitoring through sensor fusion of accelerometer and gyro-sensor","volume":"9","author":"Yoon","year":"2014","journal-title":"J. Electr. Eng. Technol."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1786","DOI":"10.1109\/TBME.2016.2621037","article-title":"Analyzing Seismocardiogram Cycles to Identify the Respiratory Phases","volume":"64","author":"Zakeri","year":"2017","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"2145","DOI":"10.1109\/JSEN.2018.2791400","article-title":"Wireless Wearable Magnetometer-Based Sensor for Sleep Quality Monitoring","volume":"18","author":"Milici","year":"2018","journal-title":"IEEE Sens. J."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1111\/j.1475-097X.1984.tb00808.x","article-title":"Impedance pneumography for long-term monitoring of respiration during sleep in adult males","volume":"4","author":"Larsen","year":"1984","journal-title":"Clin. Physiol."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"16372","DOI":"10.3390\/s150716372","article-title":"Instantaneous respiratory estimation from thoracic impedance by empirical mode decomposition","volume":"15","author":"Wang","year":"2015","journal-title":"Sensors"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/j.ijpsycho.2005.02.003","article-title":"Validation of the thoracic impedance derived respiratory signal using multilevel analysis","volume":"59","author":"Houtveen","year":"2006","journal-title":"Int. J. Psychophysiol."},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Chen, R., Chen, K., Dai, Y., and Zhang, S. (2018). Utility of transthoracic impedance and novel algorithm for sleep apnea screening in pacemaker patient. Sleep and Breathing, Springer.","DOI":"10.1007\/s11325-018-1755-y"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1273","DOI":"10.1109\/TBME.2006.871888","article-title":"A robust method for ECG-based estimation of the respiratory frequency during stress testing","volume":"53","author":"Laguna","year":"2006","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1007\/s13246-017-0612-9","article-title":"A principal component analysis based data fusion method for ECG-derived respiration from single-lead ECG","volume":"41","author":"Gao","year":"2018","journal-title":"Australas. Phys. Eng. Sci. Med."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"094001","DOI":"10.1088\/1361-6579\/abaaf0","article-title":"Comparison of different modulations of photoplethysmography in extracting respiratory rate: From a physiological perspective","volume":"41","author":"Liu","year":"2020","journal-title":"Physiol. Meas."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1007\/s11517-012-0954-0","article-title":"Deriving respiration from photoplethysmographic pulse width","volume":"51","author":"Gil","year":"2013","journal-title":"Med Biol. Eng. Comput."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"12821","DOI":"10.1109\/JSEN.2020.3023486","article-title":"Contactless Methods for Measuring Respiratory Rate: A Review","volume":"21","author":"Massaroni","year":"2020","journal-title":"IEEE Sens. J."},{"key":"ref_62","doi-asserted-by":"crossref","unstructured":"Azarbarzin, A., and Moussavi, Z.M. (2010). Automatic and unsupervised snore sound extraction from respiratory sound signals. IEEE Trans. Biomed. Eng., 58.","DOI":"10.1109\/TBME.2010.2061846"},{"key":"ref_63","doi-asserted-by":"crossref","unstructured":"Larson, E.C., Goel, M., Boriello, G., Heltshe, S., Rosenfeld, M., and Patel, S.N. (2012, January 5\u20138). Spirosmart: Using a microphone to measure lung function on a mobile phone. Proceedings of the 2012 ACM Conference on Ubiquitous Computing, Pittsburgh, PA, USA.","DOI":"10.1145\/2370216.2370261"},{"key":"ref_64","unstructured":"Murthy, R., Pavlidis, I., and Tsiamyrtzis, P. (2004, January 1\u20135). Touchless monitoring of breathing function. Proceedings of the 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, San Francisco, CA, USA."},{"key":"ref_65","unstructured":"Chekmenev, S.Y., Rara, H., and Farag, A.A. (2005, January 19\u201321). Non-contact, waveletbased measurement of vital signs using thermal imaging. Proceedings of the first international conference on graphics, vision, and image processing (GVIP), Cairo, Egypt."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1016\/0924-2716(90)90055-G","article-title":"Evaluating regional body surface motion during breathing using stereophotogrammetry","volume":"45","author":"Adams","year":"1990","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"1678","DOI":"10.1080\/10255842.2017.1406081","article-title":"Analysis of breathing via optoelectronic systems: Comparison of four methods for computing breathing volumes and thoraco-abdominal motion pattern","volume":"20","author":"Massaroni","year":"2017","journal-title":"Comput. Methods Biomech. Biomed. Eng."},{"key":"ref_68","doi-asserted-by":"crossref","unstructured":"Zanuttigh, P., Marin, G., Dal Mutto, C., Dominio, F., Minto, L., and Cortelazzo, G.M. (2016). Time-of-Flight and Structured Light Depth Cameras, Springer. Technology and Applications.","DOI":"10.1007\/978-3-319-30973-6"},{"key":"ref_69","first-page":"310","article-title":"Contactless measurement of the respiration frequency by vibrometry","volume":"2018","author":"Kroschel","year":"2018","journal-title":"Stud. Sprachkommun. Elektron. Sprachsignalverarbeitung"},{"key":"ref_70","doi-asserted-by":"crossref","unstructured":"Costanzo, S. (2019). Software-defined doppler radar sensor for human breathing detection. Sensors, 19.","DOI":"10.3390\/s19143085"},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"4838","DOI":"10.1364\/BOE.8.004838","article-title":"Novel health monitoring method using an rgb camera","volume":"8","author":"Hassan","year":"2017","journal-title":"Biomed. Opt. Express"},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"3859","DOI":"10.1109\/JSEN.2019.2960194","article-title":"Non-contact vital signs monitoring through visible light sensing","volume":"20","author":"Abuella","year":"2019","journal-title":"IEEE Sens. J."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"4941","DOI":"10.1364\/BOE.7.004941","article-title":"Robust respiration detection from remote photoplethysmography","volume":"7","author":"Stuijk","year":"2016","journal-title":"Biomed. Opt. Express"},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"610","DOI":"10.1088\/0967-3334\/37\/4\/610","article-title":"An assessment of algorithms to estimate respiratory rate from the electrocardiogram and photoplethysmogram","volume":"37","author":"Charlton","year":"2016","journal-title":"Physiol. Meas."},{"key":"ref_75","doi-asserted-by":"crossref","unstructured":"Bifulco, P., Cesarelli, M., Fratini, A., Ruffo, M., Pasquariello, G., and Gargiulo, G. (2011, January 30\u201331). A wearable device for recording of biopotentials and body movements. Proceedings of the 2011 IEEE International Symposium on Medical Measurements and Applications, Bari, Italy. Article number 59667352011.","DOI":"10.1109\/MeMeA.2011.5966735"},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"1112","DOI":"10.1109\/JSEN.2010.2082524","article-title":"Respiratory Monitoring System on the Basis of Capacitive Textile Force Sensors","volume":"11","author":"Hoffmann","year":"2011","journal-title":"IEEE Sens. J."},{"key":"ref_77","doi-asserted-by":"crossref","unstructured":"Gargiulo, G.D., Gunawardana, U., O\u2019Loughlin, A., Sadozai, M., Varaki, E.S., and Breen, P.P. (2015). A Wearable Contactless Sensor Suitable for Continuous Simultaneous Monitoring of Respiration and Cardiac Activity. J. Sens., 1\u20136.","DOI":"10.1155\/2015\/151859"},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"N35","DOI":"10.1088\/0967-3334\/36\/2\/N35","article-title":"Electro-resistive bands for non-invasive cardiac and respiration monitoring, a feasibility study","volume":"36","author":"Gargiulo","year":"2015","journal-title":"Physiol. Meas."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"87","DOI":"10.3390\/machines2010087","article-title":"Problems in assessment of novel biopotential front-end with dry electrode: A brief review","volume":"2","author":"Gargiulo","year":"2014","journal-title":"Machines"},{"key":"ref_80","doi-asserted-by":"crossref","unstructured":"Gargiulo, G., Bifulco, P., McEwan, A., Tehrani, J.N., Calvo, R.A., Romano, M., Ruffo, M., Shephard, R., Cesarelli, M., and Jin, C. (September, January 31). Dry electrode bio-potential recordings. Proceedings of the 2010 Annual International Conference of the IEEE Engineering in Medicine and Biology, Buenos Aires, Argentina.","DOI":"10.1109\/IEMBS.2010.5627359"},{"key":"ref_81","doi-asserted-by":"crossref","unstructured":"Bifulco, P., Gargiulo, G.D., D\u2019Angelo, G., Liccardo, A., Romano, M., Clemente, F., and Cesarelli, M. (2014, January 15\u201317). Monitoring of respiration, seismocardiogram and heart sounds by a PVDF piezo film sensor. Proceedings of the 20th IMEKO TC4 International Symposium and 18th International Workshop on ADC Modelling and Testing Research on Electric and Electronic Measurement for the Economic Upturn, Benevento, Italy.","DOI":"10.21014\/acta_imeko.v4i3.289"},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1109\/JSEN.2018.2877617","article-title":"A Wireless Respiratory Monitoring System Using a Wearable Patch Sensor Network","volume":"19","author":"Elfaramawy","year":"2019","journal-title":"IEEE Sens. J."},{"key":"ref_83","doi-asserted-by":"crossref","unstructured":"Al-Halhouli, A., Al-Ghussain, L., El Bouri, S., Liu, H., and Zheng, D. (2019). Fabrication and Evaluation of a Novel Non-Invasive Stretchable and Wearable Respiratory Rate Sensor Based on Silver Nanoparticles Using Inkjet Printing Technology. Polymers, 11.","DOI":"10.3390\/polym11091518"},{"key":"ref_84","doi-asserted-by":"crossref","unstructured":"Jayarathna, T., Gargiulo, G.D., and Breen, P.P. (2020). Continuous Vital Monitoring During Sleep and Light Activity Using Carbon-Black Elastomer Sensor. Sensors, 20.","DOI":"10.3390\/s20061583"},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1109\/JSEN.2019.2917617","article-title":"Smart Textile Based on Piezoresistive Sensing Elements for Respiratory Monitoring","volume":"19","author":"Massaroni","year":"2019","journal-title":"IEEE Sens. J."},{"key":"ref_86","doi-asserted-by":"crossref","unstructured":"Issatayeva, A., Beisenova, A., Tosi, D., and Molardi, C. (2020). Fiber-Optic Based Smart Textiles for Real-Time Monitoring of Breathing Rate. Sensors, 20.","DOI":"10.3390\/s20123408"},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1109\/JSEN.2020.2994264","article-title":"Design, Development and Characterization of Textile Stitch-Based Piezoresistive Sensors for Wearable Monitoring","volume":"20","author":"Choudhry","year":"2020","journal-title":"IEEE Sens. J."},{"key":"ref_88","doi-asserted-by":"crossref","unstructured":"Guay, P., Gorgutsa, S., LaRochelle, S., and Messaddeq, Y. (2017). Wearable Contactless Respiration Sensor Based on Multi-Material Fibers Integrated into Textile. Sensors, 17.","DOI":"10.3390\/s17051050"},{"key":"ref_89","doi-asserted-by":"crossref","unstructured":"Vanegas, E., Igual, R., and Plaza, I. (2020). Sensing Systems for Respiration Monitoring: A Technical Systematic Review. Sensors, 20.","DOI":"10.3390\/s20185446"},{"key":"ref_90","doi-asserted-by":"crossref","unstructured":"Andreozzi, E., Fratini, A., Esposito, D., Naik, G., Polley, C., Gargiulo, G.D., and Bifulco, P. (2020). Forcecardiography: A Novel Technique to Measure Heart Mechanical Vibrations onto the Chest Wall. Sensors, 20.","DOI":"10.3390\/s20143885"},{"key":"ref_91","doi-asserted-by":"crossref","unstructured":"Esposito, D., Andreozzi, E., Fratini, A., Gargiulo, G., Savino, S., Niola, V., and Bifulco, P. (2018). A Piezoresistive Sensor to Measure Muscle Contraction and Mechanomyography. Sensors, 18.","DOI":"10.3390\/s18082553"},{"key":"ref_92","doi-asserted-by":"crossref","first-page":"114","DOI":"10.3389\/fnbot.2019.00114","article-title":"A Piezoresistive Array Armband With Reduced Number of Sensors for Hand Gesture Recognition","volume":"13","author":"Esposito","year":"2020","journal-title":"Front. Neurorobotics"},{"key":"ref_93","doi-asserted-by":"crossref","unstructured":"Paredes-Madrid, L., Matute, A., Bare\u00f1o, J.O., Parra Vargas, C.A., and Gutierrez Vel\u00e1squez, E.I. (2017). Underlying Physics of Conductive Polymer Composites and Force Sensing Resistors (FSRs). A Study on Creep Response and Dynamic Loading. Materials, 10.","DOI":"10.3390\/ma10111334"},{"key":"ref_94","doi-asserted-by":"crossref","unstructured":"Paredes-Madrid, L., Palacio, C., Matute, A., and Parra Vargas, C. (2017). Underlying Physics of Conductive Polymer Composites and Force Sensing Resistors (FSRs) under Static Loading Conditions. Sensors, 17.","DOI":"10.3390\/s17092108"},{"key":"ref_95","doi-asserted-by":"crossref","unstructured":"Schriger, L. (2012). Approach to the patient with abnormal vital signs. Goldman\u2019s Cecil Medicine, Elsevier.","DOI":"10.1016\/B978-1-4377-1604-7.00007-5"},{"key":"ref_96","doi-asserted-by":"crossref","first-page":"671","DOI":"10.21105\/joss.00671","article-title":"BioSigKit: A Matlab Toolbox and Interface for Analysis of BioSignals","volume":"3","author":"Sedghamiz","year":"2018","journal-title":"J. Open Source Softw."},{"key":"ref_97","unstructured":"Ran, K. (2020, May 28). Bland-Altman and Correlation Plot, MATLAB Central File Exchange. Available online: https:\/\/www.mathworks.com\/matlabcentral\/fileexchange\/45049-bland-altman-and-correlation-plot."},{"key":"ref_98","doi-asserted-by":"crossref","unstructured":"Yu, S., and Liu, S. (2020). A Novel Adaptive Recursive Least Squares Filter to Remove the Motion Artifact in Seismocardiography. Sensors, 20.","DOI":"10.3390\/s20061596"},{"key":"ref_99","doi-asserted-by":"crossref","first-page":"784","DOI":"10.1109\/TBME.2018.2856700","article-title":"An Independent Component Analysis Approach to Motion Noise Cancellation of Cardio-Mechanical Signals","volume":"66","author":"Yang","year":"2018","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_100","doi-asserted-by":"crossref","first-page":"1277","DOI":"10.1109\/TBME.2016.2600945","article-title":"Quantifying and Reducing Motion Artifacts in Wearable Seismocardiogram Measurements During Walking to Assess Left Ventricular Health","volume":"64","author":"Javaid","year":"2017","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_101","doi-asserted-by":"crossref","unstructured":"Luu, L., and Dinh, A. (2018). Artifact Noise Removal Techniques on Seismocardiogram Using Two Tri-Axial Accelerometers. 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