{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T03:35:21Z","timestamp":1784691321562,"version":"3.55.0"},"reference-count":16,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T00:00:00Z","timestamp":1772582400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Objectives: To develop and validate a deep-learning model capable of detecting and quantifying intraoperative bleeding to objectively evaluate visual field impairment in unilateral biportal endoscopic spine surgery (UBE). Methods: Overall, 223,568 still images were extracted from 20 UBE videos and used to train a U-Net++ segmentation model based on the red masks generated using hue, saturation, and value (HSV) thresholding. The model was fine-tuned using 350 manually annotated images that differentiated clinically relevant bleeding (red masks) from non-bleeding red regions (zero masks). The model performance was evaluated against 180 ground-truth images annotated by three spine surgeons, which were extracted from videos that were separate from those used for training and fine-tuning. Dice and intersection-over-union (IoU) scores were calculated, and correlation analyses were performed based on inter-annotator agreement. Results: The HSV-based model reproduced the red regions with high fidelity; however, it showed limited agreement with the ground-truth bleeding regions (median Dice = 0.57, IoU = 0.40). The fine-tuned model improved substantially. For image-wise binary classification of bleeding presence, the model achieved an accuracy of 86%, with a sensitivity of 93% and a specificity of 60%. For pixel-level segmentation performance, the model achieved a median Dice score of 0.79 and a median IoU of 0.65 on ground-truth-positive images. Dice performance exceeded 0.80 in cases with strong inter-surgeon ground-truth concordance (\u22650.80) and substantial bleeding area (&gt;20%). Conclusions: This deep-learning model can accurately detect clinically meaningful intraoperative bleeding in UBE and quantify visual field impairments in still images and surgical videos. Future applications include the evaluation of hemostatic techniques, postoperative image-based assessment of surgical quality, and real-time intraoperative bleeding alerts to support surgical decision-making.<\/jats:p>","DOI":"10.3390\/jcm15051934","type":"journal-article","created":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T08:51:33Z","timestamp":1772614293000},"page":"1934","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Development of a Deep-Learning Model for Automated Detection and Quantification of Bleeding in Unilateral Biportal Endoscopic Spine Surgery"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-3211-032X","authenticated-orcid":false,"given":"Takaki","family":"Yoshimizu","sequence":"first","affiliation":[{"name":"Department of Orthopaedic Surgery, Seirei Hamamatsu General Hospital, Hamamatsu 430-8558, Japan"},{"name":"APSS-AOSpine Frontier Technologies Research Group"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4189-9270","authenticated-orcid":false,"given":"Daisuke","family":"Sakai","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Tokai University Hospital, Isehara 259-1193, Japan"},{"name":"APSS-AOSpine Frontier Technologies Research Group"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1111-3508","authenticated-orcid":false,"given":"Daiki","family":"Morita","sequence":"additional","affiliation":[{"name":"Department of Plastic and Reconstructive Surgery, Tokai University Hospital, Isehara 259-1193, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1606-2444","authenticated-orcid":false,"given":"Meng-Huang","family":"Wu","sequence":"additional","affiliation":[{"name":"Department of Orthopedics, Taipei Medical University Hospital, Taipei 110, Taiwan"},{"name":"APSS-AOSpine Frontier Technologies Research Group"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Teruaki","family":"Miyake","sequence":"additional","affiliation":[{"name":"Department of Spine and Bone Tumors, Seirei Hamamatsu General Hospital, Hamamatsu 430-8558, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sanshiro","family":"Saito","sequence":"additional","affiliation":[{"name":"Department of Spine and Bone Tumors, Seirei Hamamatsu General Hospital, Hamamatsu 430-8558, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tetsutaro","family":"Mizuno","sequence":"additional","affiliation":[{"name":"Department of Spine and Bone Tumors, Seirei Hamamatsu General Hospital, Hamamatsu 430-8558, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ushio","family":"Nosaka","sequence":"additional","affiliation":[{"name":"Department of Spine and Bone Tumors, Seirei Hamamatsu General Hospital, Hamamatsu 430-8558, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keisuke","family":"Ishii","sequence":"additional","affiliation":[{"name":"Department of Spine and Bone Tumors, Seirei Hamamatsu General Hospital, Hamamatsu 430-8558, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mizuki","family":"Watanabe","sequence":"additional","affiliation":[{"name":"Department of Spine and Bone Tumors, Seirei Hamamatsu General Hospital, Hamamatsu 430-8558, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kanji","family":"Sasaki","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Seirei Hamamatsu General Hospital, Hamamatsu 430-8558, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1186\/s13018-018-0725-1","article-title":"Clinical comparison of unilateral biportal endoscopic technique versus open microdiscectomy for single-level lumbar discectomy: A multicenter, retrospective analysis","volume":"13","author":"Kim","year":"2018","journal-title":"J. Orthop. Surg. Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3274","DOI":"10.1007\/s00586-022-07421-6","article-title":"Incidence of postoperative symptomatic spinal epidural hematoma requiring surgical evacuation: A systematic review and meta-analysis","volume":"31","author":"Chen","year":"2022","journal-title":"Eur. Spine J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"425","DOI":"10.1016\/j.wneu.2019.02.038","article-title":"A systematic review of unilateral biportal endoscopic spinal surgery: Preliminary clinical results and complications","volume":"125","author":"Lin","year":"2019","journal-title":"World Neurosurg."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1111\/os.13437","article-title":"Complications of unilateral biportal endoscopic spinal surgery for lumbar spinal stenosis: A systematic review of the literature and meta-analysis of single-arm studies","volume":"15","author":"Wang","year":"2023","journal-title":"Orthop. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e91","DOI":"10.1016\/j.wneu.2021.12.005","article-title":"Efficacy and complications of unilateral biportal endoscopic spinal surgery for lumbar spinal stenosis: A meta-analysis and systematic review","volume":"159","author":"Liang","year":"2022","journal-title":"World Neurosurg."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1097\/BSD.0000000000001211","article-title":"A primer on the use of artificial intelligence in spine surgery","volume":"34","author":"Katsuura","year":"2021","journal-title":"Clin. Spine Surg."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1405","DOI":"10.1177\/21925682241274372","article-title":"Artificial intelligence-assisted MRI diagnosis in lumbar degenerative disc disease: A systematic review","volume":"15","author":"Liawrungrueang","year":"2025","journal-title":"Glob. Spine J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"382","DOI":"10.1111\/den.13507","article-title":"Artificial intelligence using a convolutional neural network for automatic detection of small-bowel angioectasia in capsule endoscopy images","volume":"32","author":"Tsuboi","year":"2020","journal-title":"Dig. Endosc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1445","DOI":"10.1177\/21925682241290752","article-title":"Current applications and future implications of artificial intelligence in spine surgery and research: A narrative review and commentary","volume":"15","author":"Yahanda","year":"2025","journal-title":"Glob. Spine J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"602","DOI":"10.3171\/2015.7.SPINE15304","article-title":"Percutaneous biportal endoscopic decompression for lumbar spinal stenosis: A technical note and preliminary clinical results","volume":"24","author":"Son","year":"2016","journal-title":"J. Neurosurg. Spine"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e22.00020","DOI":"10.2106\/JBJS.ST.22.00020","article-title":"Unilateral biportal endoscopy for lumbar spinal stenosis and lumbar disc herniation","volume":"13","author":"Park","year":"2023","journal-title":"JBJS Essent. Surg. Tech."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"123386","DOI":"10.1016\/j.wneu.2024.10.115","article-title":"Clinical efficacy and complications of spinal surgery unilateral biportal endoscopy for cervical spondylosis: A systematic review and meta-analysis","volume":"194","author":"Li","year":"2025","journal-title":"World Neurosurg."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"43","DOI":"10.14245\/ns.2346236.118","article-title":"The role and future of endoscopic spine surgery: A narrative review","volume":"20","author":"Kwon","year":"2023","journal-title":"Neurospine"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Kim, D.-G., Park, E.J., Min, W.-K., Kim, S.-B., Lee, G., and Choi, S. (2025). Comparison of hidden blood loss in biportal endoscopic spine surgery and open surgery in the lumbar spine: A retrospective multicenter study. J. Clin. Med., 14.","DOI":"10.3390\/jcm14113878"},{"key":"ref_15","first-page":"3","article-title":"UNet++: A nested U-Net architecture for medical image segmentation","volume":"Volume 11045","author":"Zhou","year":"2018","journal-title":"Deep Learning in Medical Image Analysis and Multimodal Learning for Clinical Decision Support"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"295","DOI":"10.70594\/brain\/15.4\/20","article-title":"Selecting the right metric: A detailed study on image segmentation evaluation","volume":"15","author":"Boiangiu","year":"2025","journal-title":"BRAIN Broad Res. Artif. Intell. Neurosci."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/5\/1934\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T09:22:21Z","timestamp":1772616141000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/5\/1934"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,4]]},"references-count":16,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["jcm15051934"],"URL":"https:\/\/doi.org\/10.3390\/jcm15051934","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,4]]}}}