{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T06:22:14Z","timestamp":1783059734255,"version":"3.54.6"},"reference-count":37,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T00:00:00Z","timestamp":1783036800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Rehabil. Sci."],"abstract":"<jats:p>More than 85% of stroke survivors present motor impairment in the upper limb, yet access to rehabilitation robotics remains concentrated in high-income countries due to costs exceeding 10,000 USD and architectures dependent on external computers. This economic barrier limits the ability of researchers in low- and middle-income countries (LMICs) to develop and validate new therapeutic strategies. This article presents PETRA (Pedestal Exoskeletal Testbed with Real-time Architecture), an open-source, 3-degree-of-freedom kinematic validation testbed manufactured in PETG for upper limb rehabilitation research at a cost under 25 USD per joint. PETRA adopts a fixed pedestal configuration that decouples the robot\u2019s dynamics from the user\u2019s biomechanical disturbances, providing a controlled environment for characterizing parametric cycloidal transmissions and deterministic dual-core firmware without PC\/ROS dependency. Experimental validation with over 300 trials confirms positioning accuracies within clinical requirements while identifying polymer friction as the primary technical constraint. By providing a low-cost, replicable methodological standard, PETRA facilitates the transition from conceptual design to robust assistive technology in institutions with limited resources.<\/jats:p>","DOI":"10.3389\/fresc.2026.1859475","type":"journal-article","created":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T05:41:00Z","timestamp":1783057260000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["PETRA: a pedestal exoskeletal testbed with real-time architecture for upper limb rehabilitation robotics"],"prefix":"10.3389","volume":"7","author":[{"given":"Andres","family":"Garcia","sequence":"first","affiliation":[{"name":"Facultad de Ingenier\u00eda en Mec\u00e1nica y Ciencias de la Producci\u00f3n, Escuela Superior Politecnica del Litoral, ESPOL","place":["Guayaquil, Ecuador"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevin","family":"Fern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Facultad de Ingenier\u00eda en Mec\u00e1nica y Ciencias de la Producci\u00f3n, Escuela Superior Politecnica del Litoral, ESPOL","place":["Guayaquil, Ecuador"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andres","family":"Nenger","sequence":"additional","affiliation":[{"name":"Facultad de Ingenier\u00eda en Mec\u00e1nica y Ciencias de la Producci\u00f3n, Escuela Superior Politecnica del Litoral, ESPOL","place":["Guayaquil, Ecuador"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Redhwan","family":"Algabri","sequence":"additional","affiliation":[{"name":"Department of Computer Science and Engineering, Sejong University","place":["Seoul, Republic of 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