A Wearable Stethoscope for Long-Term Ambulatory Respiratory Health Monitoring
Abstract
:1. Introduction
2. Thoracic Sound Acquisition Module Design
2.1. Transducer Design
2.2. Sensor Electronics Design
2.2.1. High-Impedance Sensor Interface
2.2.2. Signal Conditioning and Quantization
2.3. Fabrication and Integration
3. Evaluation and Comparative Analysis
- Spectral rolloff estimates the amount of high frequency in the signal by finding the frequency below which a defined percentage of the total spectral energy is contained (in this case, 85%).
- Spectral brightness estimates the amount of high frequency in the signal by measuring the amount of energy above a cut-off frequency (in this case, 500 Hz, the frequency below which Littmann 3200 enhances the signal).
- Spectral centroid is the center of mass of the spectrum.
- Spectral spread indicates the spread of the spectrum around its mean value.
4. Discussion and Conclusions
Author Contributions
Funding
Conflicts of Interest
References
- Lee, K.; Ni, X.; Lee, J.Y.; Arafa, H.; Pe, D.J.; Xu, S.; Avila, R.; Irie, M.; Lee, J.H.; Easterlin, R.L.; et al. Mechano-acoustic sensing of physiological processes and body motions via a soft wireless device placed at the suprasternal notch. Nat. Biomed. Eng. 2019, 4, 148–158. [Google Scholar] [CrossRef] [PubMed]
- Proaño, A.; A Bravard, M.; Tracey, B.H.; López, J.W.; Comina, G.; Zimic, M.; Coronel, J.; Lee, G.O.; Caviedes, L.; Cabrera, J.L.; et al. Protocol for studying cough frequency in people with pulmonary tuberculosis. BMJ Open 2016, 6, e010365. [Google Scholar] [CrossRef] [PubMed]
- McGuinness, K.; Holt, K.J.; Dockry, R.; Smith, J. P159 Validation of the VitaloJAK™ 24 Hour Ambulatory Cough Monitor. Thorax 2012, 67, A131. [Google Scholar] [CrossRef] [Green Version]
- Grossman, P. The LifeShirt: A multi-function ambulatory system monitoring health, disease, and medical intervention in the real world. Stud. Heal. Technol. Inform. 2004, 108, 133–141. [Google Scholar]
- Rapin, M.; Braun, F.; Adler, A.; Wacker, J.; Frerichs, I.; Vogt, B.; Chetelat, O. Wearable Sensors for Frequency-Multiplexed EIT and Multilead ECG Data Acquisition. IEEE Trans. Biomed. Eng. 2018, 66, 810–820. [Google Scholar] [CrossRef] [PubMed]
- Klum, M.; Urban, M.; Tigges, T.; Pielmus, A.-G.; Feldheiser, A.; Schmitt, T.; Orglmeister, R. Wearable Cardiorespiratory Monitoring Employing a Multimodal Digital Patch Stethoscope: Estimation of ECG, PEP, LVET and Respiration Using a 55 mm Single-Lead ECG and Phonocardiogram. Sensors 2020, 20, 2033. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Sen, I.; Kahya, Y. A Multi-Channel Device for Respiratory Sound Data Acquisition and Transient Detection. In Proceedings of the 2005 IEEE Engineering in Medicine and Biology 27th Annual Conference, Shanghai, China, 17–18 January 2006; pp. 6658–6661. [Google Scholar]
- Messner, E.; Hagmüller, M.; Swatek, P.; Pernkopf, F. A Robust Multichannel Lung Sound Recording Device. In Proceedings of the 9th International Joint Conference on Biomedical Engineering Systems and Technologies, Rome, Italy, 21–23 February 2016; pp. 34–39. [Google Scholar] [CrossRef] [Green Version]
- Panda, B.; Mandal, S.; Majerus, S. Flexible, Skin Coupled Microphone Array for Point of Care Vascular Access Monitoring. IEEE Trans. Biomed. Circuits Syst. 2019, 13, 1494–1505. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Cotur, Y.; Kasimatis, M.; Kaisti, M.; Olenik, S.; Georgiou, C.; Güder, F. Stretchable Composite Acoustic Transducer for Wearable Monitoring of Vital Signs. Adv. Funct. Mater. 2020, 30, 1910288. [Google Scholar] [CrossRef]
- Kraman, S.S.; Wodicka, G.R.; Pressler, G.A.; Pasterkamp, H. Comparison of lung sound transducers using a bioacoustic transducer testing system. J. Appl. Physiol. 2006, 101, 469–476. [Google Scholar] [CrossRef] [PubMed]
- Kraman, S.S.; Wodicka, G.R.; Oh, Y.; Pasterkamp, H. Measurement of Respiratory Acoustic Signals. Chest 1995, 108, 1004–1008. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Zanartu, M.; Ho, J.C.; Kraman, S.S.; Pasterkamp, H.; Huber, J.E.; Wodicka, G.R. Air-Borne and Tissue-Borne Sensitivities of Bioacoustic Sensors Used on the Skin Surface. IEEE Trans. Biomed. Eng. 2008, 56, 443–451. [Google Scholar] [CrossRef] [PubMed]
- Murphy, R. Computerized multichannel lung sound analysis. Development of acoustic instruments for diagnosis and management of medical conditions. IEEE Eng. Med. Boil. Mag. 2007, 26, 16–19. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Burch, C.R.; Stock, J.P.P. A new diaphragmatic stethoscope. Br. Heart J. 1961, 23, 447–454. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Abbas, A.K.; Bassam, R. Phonocardiography Signal Processing. Synth. Lect. Biomed. Eng. 2009, 4, 1–194. [Google Scholar] [CrossRef]
- Eshach, H.; Volfson, A. Explanatory model for sound amplification in a stethoscope. Phys. Educ. 2014, 50, 75–80. [Google Scholar] [CrossRef]
- Toda, M.; Thompson, M. Contact-Type Vibration Sensors Using Curved Clamped PVDF Film. IEEE Sensors J. 2006, 6, 1170–1177. [Google Scholar] [CrossRef]
- Littrell, R.J. High Performance Piezoelectric MEMS Microphones. Ph.D. Thesis, University of Michigan, Ann arbor, MI, USA, 2010. [Google Scholar]
- Naono, H.; Gotoh, T.; Matsumoto, M.; Ibaraki, S.; Rikow, Y. Design of an Electro-Acoustic Transducer Using Piezoelectric Polymer Film. Available online: http://www.aes.org/e-lib/online/browse.cfm?elib=3083 (accessed on 16 March 2020).
- Starecki, T. Analog Front-End Circuitry in Piezoelectric and Microphone Detection of Photoacoustic Signals. Int. J. Thermophys. 2014, 35, 2124–2139. [Google Scholar] [CrossRef] [Green Version]
- Ried, R.; Kim, E.S.; Hong, D.; Muller, R. Piezoelectric microphone with on-chip CMOS circuits. J. Microelectromechanical Syst. 1993, 2, 111–120. [Google Scholar] [CrossRef]
- Regtien, P.P.L. Sensors for Mechatronics; Elsevier: Amsterdam, The Netherlands, 2012. [Google Scholar]
- Lartillot, O.; Toiviainen, P.; Eerola, T. A Matlab Toolbox for Music Information Retrieval. In Studies in Classification, Data Analysis, and Knowledge Organization; Springer Science and Business: Berlin/Heidelberg, Germany, 2008; pp. 261–268. [Google Scholar]
- Oliynik, V. On potential effectiveness of integration of 3M Littmann 3200 electronic stethoscopes into the third-party diagnostic systems with auscultation signal processing. In Proceedings of the 2015 IEEE 35th International Conference on Electronics and Nanotechnology (ELNANO), Kiev, Ukraine, 21–24 April 2015; pp. 417–421. [Google Scholar]
- Dalmay, F.; Antonini, M.; Marquet, P.; Menier, R. Acoustic properties of the normal chest. Eur. Respir. J. 1995, 8, 1761–1769. [Google Scholar] [CrossRef] [PubMed] [Green Version]
Sensor | Rolloff (Hz) | Brightness (%) | Centroid (Hz) | Spread (Hz) | |
---|---|---|---|---|---|
Full signal | Sensor | 27.01 | 4.37 | 71.30 | 277.89 |
Lit. Bell | 52.25 | 1.90 | 42.56 | 169.71 | |
Lit. Diaphragm | 96.37 | 3.73 | 64.90 | 193.57 | |
Lit. Extended | 100.59 | 4.22 | 67.81 | 189.89 | |
Breathing | Sensor | 63.78 | 6.00 | 94.15 | 306.92 |
Lit. Bell | 20.02 | 3.12 | 48.08 | 215.43 | |
Lit. Diaphragm | 40.83 | 4.63 | 63.21 | 224.87 | |
Lit. Extended | 51.57 | 5.51 | 66.92 | 229.69 | |
Cough | Sensor | 14.16 | 2.75 | 45.52 | 210.94 |
Lit. Bell | 61.52 | 1.62 | 44.34 | 160.52 | |
Lit. Diaphragm | 112.79 | 3.69 | 74.12 | 184.41 | |
Lit. Extended | 103.52 | 3.94 | 70.49 | 181.34 | |
Speech | Sensor | 43.95 | 4.87 | 79.13 | 278.23 |
Lit. Bell | 114.75 | 1.61 | 55.28 | 159.72 | |
Lit. Diaphragm | 243.65 | 4.51 | 112.80 | 194.11 | |
Lit. Extended | 132.81 | 4.75 | 105.38 | 188.34 |
Sensor | Rolloff (Hz) | Brightness (%) | Centroid (Hz) | Spread (Hz) | |
---|---|---|---|---|---|
Full signal | Sensor | 15.63 | 2.49 | 41.28 | 198.10 |
Lit. Bell | 52.98 | 1.44 | 40.71 | 148.51 | |
Lit. Diaphragm | 117.43 | 4.03 | 75.80 | 189.13 | |
Lit. Extended | 101.87 | 4.03 | 69.09 | 183.11 | |
Breathing | Sensor | 22.40 | 4.25 | 65.83 | 250.77 |
Lit. Bell | 56.40 | 1.14 | 39.82 | 134.71 | |
Lit. Diaphragm | 97.72 | 5.76 | 84.79 | 210.69 | |
Lit. Extended | 91.80 | 6.17 | 83.34 | 203.04 | |
Cough | Sensor | 14.65 | 2.34 | 39.44 | 196.62 |
Lit. Bell | 49.80 | 1.84 | 44.56 | 169.08 | |
Lit. Diaphragm | 114.26 | 3.63 | 72.19 | 191.17 | |
Lit. Extended | 100.10 | 3.66 | 66.02 | 189.45 | |
Speech | Sensor | 20.51 | 3.75 | 65.67 | 254.94 |
Lit. Bell | 68.85 | 1.55 | 50.13 | 165.18 | |
Lit. Diaphragm | 124.51 | 3.69 | 87.66 | 181.75 | |
Lit. Extended | 120.61 | 3.94 | 81.30 | 180.99 |
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Yilmaz, G.; Rapin, M.; Pessoa, D.; Rocha, B.M.; de Sousa, A.M.; Rusconi, R.; Carvalho, P.; Wacker, J.; Paiva, R.P.; Chételat, O. A Wearable Stethoscope for Long-Term Ambulatory Respiratory Health Monitoring. Sensors 2020, 20, 5124. https://doi.org/10.3390/s20185124
Yilmaz G, Rapin M, Pessoa D, Rocha BM, de Sousa AM, Rusconi R, Carvalho P, Wacker J, Paiva RP, Chételat O. A Wearable Stethoscope for Long-Term Ambulatory Respiratory Health Monitoring. Sensors. 2020; 20(18):5124. https://doi.org/10.3390/s20185124
Chicago/Turabian StyleYilmaz, Gürkan, Michaël Rapin, Diogo Pessoa, Bruno M. Rocha, Antonio Moreira de Sousa, Roberto Rusconi, Paulo Carvalho, Josias Wacker, Rui Pedro Paiva, and Olivier Chételat. 2020. "A Wearable Stethoscope for Long-Term Ambulatory Respiratory Health Monitoring" Sensors 20, no. 18: 5124. https://doi.org/10.3390/s20185124
APA StyleYilmaz, G., Rapin, M., Pessoa, D., Rocha, B. M., de Sousa, A. M., Rusconi, R., Carvalho, P., Wacker, J., Paiva, R. P., & Chételat, O. (2020). A Wearable Stethoscope for Long-Term Ambulatory Respiratory Health Monitoring. Sensors, 20(18), 5124. https://doi.org/10.3390/s20185124