{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T14:50:21Z","timestamp":1781621421615,"version":"3.54.5"},"reference-count":24,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2014,9,19]],"date-time":"2014-09-19T00:00:00Z","timestamp":1411084800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The pulse oximeter is a popular instrument to monitor the arterial oxygen saturation (SPO2). Although a fingertip-type pulse oximeter is the mainstream one on the market at present, it is still inconvenient for long-term monitoring, in particular, with respect to motion. Therefore, the development of a wearable pulse oximeter, such as a finger base-type pulse oximeter, can effectively solve the above issue. However, the tissue structure of the finger base is complex, and there is lack of detailed information on the effect of the light source and detector placement on measuring SPO2. In this study, the practicability of a ring-type pulse oximeter with a multi-detector was investigated by optical human tissue simulation. The optimal design of a ring-type pulse oximeter that  can provide the best efficiency of measuring SPO2 was discussed. The efficiency of  ring-type pulse oximeters with a single detector and a multi-detector was also discussed. Finally, a wearable and wireless ring-type pulse oximeter was also implemented to validate the simulation results and was compared with the commercial fingertip-type pulse oximeter.<\/jats:p>","DOI":"10.3390\/s140917586","type":"journal-article","created":{"date-parts":[[2014,9,19]],"date-time":"2014-09-19T11:03:02Z","timestamp":1411124582000},"page":"17586-17599","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":40,"title":["Novel Wearable and Wireless Ring-Type Pulse Oximeter with Multi-Detectors"],"prefix":"10.3390","volume":"14","author":[{"given":"Cheng-Yang","family":"Huang","sequence":"first","affiliation":[{"name":"Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan 711, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ming-Che","family":"Chan","sequence":"additional","affiliation":[{"name":"Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan 711, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chien-Yue","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Electronics Engineering, National Yunlin University of Science and Technology, Yunlin 640, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bor-Shyh","family":"Lin","sequence":"additional","affiliation":[{"name":"Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan 711, Taiwan"},{"name":"Department of Medical Research, Chi-Mei Medical Center, Tainan 710, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2014,9,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"16882","DOI":"10.3390\/s131216882","article-title":"Design and Evaluation of a Low-Cost Smartphone Pulse Oximeter","volume":"13","author":"Petersen","year":"2013","journal-title":"Sensors"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"10980","DOI":"10.3390\/s120810980","article-title":"Use of a Combined SpO2\/PtcCO2 Sensor in the Delivery Room","volume":"12","author":"Rubortone","year":"2012","journal-title":"Sensors"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1016\/S0921-8890(99)00092-5","article-title":"Development of the ring sensor for healthcare automation","volume":"30","author":"Yang","year":"2000","journal-title":"Robot. Auton. Syst."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1109\/MEMB.2003.1213624","article-title":"Mobile monitoring with wearable photoplethysmographic biosensors","volume":"22","author":"Asada","year":"2003","journal-title":"IEEE Eng. Med. Biol. Mag."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1746","DOI":"10.1364\/JOSAA.10.001746","article-title":"Hybrid model of Monte Carlo simulation and diffusion theory for light reflectance by turbid media","volume":"10","author":"Wang","year":"1993","journal-title":"J. Opt. Soc. Am."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1859","DOI":"10.1088\/0031-9155\/38\/12\/011","article-title":"A Monte Carlo investigation of optical pathlength in inhomogeneous tissue and its application to near-infrared","volume":"38","author":"Hiraoka","year":"1993","journal-title":"Phys. Med. Biol. Inst."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1109\/TBME.2004.840188","article-title":"Multilayer Modeling of Reflectance Pulse Oximetry","volume":"52","author":"Reuss","year":"2005","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/0169-2607(95)01640-F","article-title":"MCML-Monte Carlo modeling of light transport in multi-layered tissues","volume":"47","author":"Wang","year":"1995","journal-title":"Comput. Methods Progr. Biomed."},{"key":"ref_9","first-page":"012027-1","article-title":"Validation of a Monte Carlo platform for the optical modelling of pulse oximetry","volume":"85","author":"Peris","year":"2007","journal-title":"J. Phys."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"869","DOI":"10.1088\/0967-3334\/30\/9\/001","article-title":"Vessel calibre and haemoglobin effects on pulse oximetry","volume":"30","author":"McEwen","year":"2009","journal-title":"Physiol. Meas."},{"key":"ref_11","first-page":"1","article-title":"A Noncontact Skin Oxygen-Saturation Imaging System for Measuring Human Tissue Oxygen Saturation","volume":"99","author":"Tsai","year":"2014","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"010501:1","DOI":"10.1117\/1.JBO.17.1.010501","article-title":"Hybrid method for fast Monte Carlo simulation of diffuse reflectance from a multilayered tissue model with tumor-like heterogeneities","volume":"17","author":"Zhu","year":"2012","journal-title":"J. Biomed. Opt."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1070\/PU1997v040n05ABEH000236","article-title":"Light scattering study of tissues","volume":"40","author":"Tuchin","year":"1997","journal-title":"Phys. Uspekhi"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Netz, U.J., Scheel, A.K., Beuthan, J., and Hielscher, A.H. (2006, January 30). Development of a finger joint phantom for evaluation of frequency domain measurement systems. New York, NY, USA.","DOI":"10.1109\/IEMBS.2006.259302"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"638","DOI":"10.1134\/1.1914906","article-title":"Immersion clearing of human blood in the visible and near-infrared spectral regions","volume":"98","author":"Bashkatov","year":"2005","journal-title":"Opt. Spectrosc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1479","DOI":"10.1088\/0031-9155\/51\/6\/008","article-title":"Refractive indices of human skin tissues at eight wavelengths and estimated dispersion relations between 300 and 1600 nm","volume":"51","author":"Ding","year":"2006","journal-title":"Phys. Med. Biol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"028102:1","DOI":"10.1103\/PhysRevLett.93.028102","article-title":"Oxygen saturation-dependent absorption and scattering of blood","volume":"93","author":"Faber","year":"2004","journal-title":"Phys. Rev. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"4013","DOI":"10.1088\/0031-9155\/56\/13\/017","article-title":"The refractive index of human hemoglobin in the visible range","volume":"56","author":"Zhernovaya","year":"2011","journal-title":"Phys. Med. Biol."},{"key":"ref_19","unstructured":"Locking, P.M., and Banks, D.P. (2007, January 16). A Simple Source Temperature Dependent Human Burn Injury Model. Tarragona, Spain."},{"key":"ref_20","first-page":"35","article-title":"The optics of human skin: Aspects important for human health","volume":"2008","author":"Nielsen","year":"2008","journal-title":"Nor. Acad. Sci. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Doemer, B., Klausmann, D., Bindig, U., Gersonde, I., Schwaibold, M., Schoeller, B., and Kotterba, B. (2009, January 7). Measurement of Optical Pulsation and Transmission Spectra as Reference for a Monte Carlo Simulation of the Finger Tip. Munich, Germany.","DOI":"10.1007\/978-3-642-03882-2_356"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"836","DOI":"10.1134\/1.2135863","article-title":"Optical properties of the subcutaneous adipose tissue in the spectral range 400\u2013nm","volume":"99","author":"Bashkatov","year":"2005","journal-title":"Opt. Spectrosc."},{"key":"ref_23","first-page":"147","article-title":"Modeling and measurements of light transmission through human tissues","volume":"56","author":"Krawiecki","year":"2008","journal-title":"Bull. Polish Acad. Sci. Tech. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1013","DOI":"10.2214\/ajr.152.5.1013","article-title":"MR imaging of the finger: correlation with normal anatomic sections","volume":"152","author":"Erickson","year":"1989","journal-title":"Am. J. Roentgenol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/14\/9\/17586\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:16:07Z","timestamp":1760217367000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/14\/9\/17586"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,9,19]]},"references-count":24,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2014,9]]}},"alternative-id":["s140917586"],"URL":"https:\/\/doi.org\/10.3390\/s140917586","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,9,19]]}}}