{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T01:45:23Z","timestamp":1760060723810,"version":"build-2065373602"},"reference-count":37,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,9,15]],"date-time":"2025-09-15T00:00:00Z","timestamp":1757894400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"FANCL Corporation"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medical Sciences"],"abstract":"<jats:p>Background: In exercise testing, the ventilatory threshold 1 (VT1) and ventilatory threshold 2 (VT2) are used in lifestyle-related diseases, cardiac rehabilitation, and athletic training. We investigated a VT2 measuring method using a pulse oximeter. Methods: Thirty-four adults (men: 15; women: 19) performed a bicycle ergometer Ramp Test. VT1 values were determined using expiratory gas data. The bifurcation of the curve obtained by designating the pulse rate (PR) as an independent variable and SpO2\/PR as a dependent variable was calculated using the residual sum of squares and defined as the SpO2 threshold (ST) (SpO2-Slope method). A second bifurcation with ST as the origin was further defined (ST2). ST2 validity was assessed by comparing and analyzing the differences and correlations with each VT2 obtained by expiratory gas analysis. Results: The correlation between ST2 determined by the SpO2-Slope method using PR as an index and VT2 obtained from respiratory gas analysis was significant, showing a positive correlation (r = 0.74~0.92; p &lt; 0.01), with most data points falling within the 1.96 \u00b1 SD in the Bland\u2013Altman analysis. Conclusions: ST2 values derived from SpO2 and pulse rate measurements by pulse oximeter may be a valuable VT2 measuring method.<\/jats:p>","DOI":"10.3390\/medsci13030192","type":"journal-article","created":{"date-parts":[[2025,9,15]],"date-time":"2025-09-15T16:27:33Z","timestamp":1757953653000},"page":"192","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Novel Method to Determine the Respiratory Compensation Point from Percutaneous Oxygen Saturation of Healthy Adults During a Ramp-Incremental Test: A Cross-Sectional Study"],"prefix":"10.3390","volume":"13","author":[{"given":"Masatsugu","family":"Abe","sequence":"first","affiliation":[{"name":"FANCL New Business Head Office, 12-13 Kamishinano, Totsuka-ku, Yokohama 244-0806, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5195-1808","authenticated-orcid":false,"given":"Kai","family":"Ushio","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan"},{"name":"Department of Rehabilitation Medicine, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masaya","family":"Tsubokawa","sequence":"additional","affiliation":[{"name":"FANCL Corporation Research Institute, 12-13 Kamishinano, Totsuka-ku, Yokohama 244-0806, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1681-0035","authenticated-orcid":false,"given":"Koki","family":"Fukuhara","sequence":"additional","affiliation":[{"name":"Division of Rehabilitation, Department of Clinical Practice and Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8595-0846","authenticated-orcid":false,"given":"Yoshitaka","family":"Iwamoto","sequence":"additional","affiliation":[{"name":"Division of Rehabilitation, Department of Clinical Practice and Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daisuke","family":"Iwaki","sequence":"additional","affiliation":[{"name":"Division of Rehabilitation, Department of Clinical Practice and Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7838-9472","authenticated-orcid":false,"given":"Yuki","family":"Nakashima","sequence":"additional","affiliation":[{"name":"Division of Rehabilitation, Department of Clinical Practice and Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takeshi","family":"Nakamura","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yukio","family":"Mikami","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"484","DOI":"10.1016\/j.bja.2017.10.020","article-title":"Perioperative cardiopulmonary exercise testing (CPET): Consensus clinical guidelines on indications, organization, conduct, and physiological interpretation","volume":"120","author":"Levett","year":"2018","journal-title":"Br. 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