{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T05:07:48Z","timestamp":1787029668806,"version":"build-2736575974"},"reference-count":14,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T00:00:00Z","timestamp":1779321600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science and Higher Education of the Republic of Kazakhstan","award":["BR24992820"],"award-info":[{"award-number":["BR24992820"]}]},{"award":["BR24992820"],"award-info":[{"award-number":["BR24992820"]}],"id":[{"id":"https:\/\/ror.org\/05tyne317","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Lower-limb amputation remains a significant clinical and socio-economic challenge, while the high cost of microprocessor-controlled prostheses (MPKs) limits their widespread accessibility. This paper presents the design and preliminary laboratory-scale evaluation of a low-cost microprocessor-controlled ankle prosthesis intended as a feasibility-oriented alternative platform for future active prosthetic system development. Building upon the previously developed V1 mechanical architecture, an updated CAD model was created in the SolidWorks 2024 environment, and the kinematic configuration was refined using a ball-screw transmission (SFU1204-300) driven by a NEMA 17 stepper motor. The electronic control system integrates an ESP32 microcontroller, an MPU9250 inertial measurement unit (IMU), a limit switch for initial-position detection, and a WiFi-based REST API interface for communication and control. Laboratory no-load experiments demonstrated controlled positional behavior, repeatable angular response, and successful operation of the homing procedure within a motion range of 0\u20134200 motor steps. The prototype actively generated dorsiflexion\u2013plantar flexion motion in the sagittal plane, while a passive inversion\u2013eversion mechanism was incorporated and intended to improve structural adaptability. IMU-based measurements enabled preliminary monitoring of angular displacement and positional behavior during the experiments. The presented prototype represents an initial engineering feasibility study of a low-cost active ankle actuation architecture and provides a foundation for future investigations involving load-bearing experiments, biomechanical gait analysis, and closed-loop control implementation.<\/jats:p>","DOI":"10.3390\/s26103257","type":"journal-article","created":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T09:29:58Z","timestamp":1779355798000},"page":"3257","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Design and Initial Evaluation of a Low-Cost Microprocessor-Controlled Ankle Prosthesis"],"prefix":"10.3390","volume":"26","author":[{"given":"Zhanar","family":"Bigaliyeva","sequence":"first","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5941-3462","authenticated-orcid":false,"given":"Abu-Alim","family":"Ayazbay","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"},{"name":"Department Aerospace and Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0467-1667","authenticated-orcid":false,"given":"Sayat","family":"Akhmejanov","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3358-1182","authenticated-orcid":false,"given":"Nursultan","family":"Zhetenbayev","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"},{"name":"Department Aerospace and Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"},{"name":"Department of Science and Innovations, Mukhametzhan Tynyshbayev ALT University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7548-2954","authenticated-orcid":false,"given":"Aidos","family":"Sultan","sequence":"additional","affiliation":[{"name":"Department Aerospace and Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9712-5592","authenticated-orcid":false,"given":"Yerkebulan","family":"Nurgizat","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"},{"name":"Department Aerospace and Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abu Jazar","family":"Ussam","sequence":"additional","affiliation":[{"name":"Department of Prosthetic and Orthopedic Care, National Scientific Center for Development of Social Protection of the Ministry of Labor and Social Protection of the Republic of Kazakhstan, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2044-8027","authenticated-orcid":false,"given":"Gulzhamal","family":"Tursunbayeva","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-6728-0748","authenticated-orcid":false,"given":"Arman","family":"Uzbekbayev","sequence":"additional","affiliation":[{"name":"Department Aerospace and Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kassymbek","family":"Ozhikenov","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gani","family":"Sergazin","sequence":"additional","affiliation":[{"name":"Department of Science and Innovations, Mukhametzhan Tynyshbayev ALT University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yelubayeva","family":"Lazzat","sequence":"additional","affiliation":[{"name":"Department of Science and Innovations, Mukhametzhan Tynyshbayev ALT University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"60","DOI":"10.3390\/prosthesis4010007","article-title":"Design and Initial Evaluation of a Low-Cost Microprocessor-Controlled Above-Knee Prosthesis: A Case Report of 2 Patients","volume":"4","author":"Gailey","year":"2022","journal-title":"Prosthesis"},{"key":"ref_2","first-page":"100376","article-title":"Estimating Recent US Limb Loss Prevalence and Updating Future Projections","volume":"6","author":"Rivera","year":"2024","journal-title":"Arch. Rehabil. Res. Clin. Transl."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"563","DOI":"10.1097\/01.phm.0000174665.74933.0b","article-title":"A Clinical Comparison of Variable-Damping and Mechanically Passive Prosthetic Knee Devices","volume":"84","author":"Johansson","year":"2005","journal-title":"Am. J. Phys. Med. Rehabil."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1682\/JRRD.2006.11.0147","article-title":"Review of Secondary Physical Conditions Associated with Lower-Limb Amputation and Long-Term Prosthesis Use","volume":"45","author":"Gailey","year":"2008","journal-title":"J. Rehabil. Res. Dev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1682\/JRRD.2008.09.0131","article-title":"Agonist-Antagonist Active Knee Prosthesis: A Preliminary Study in Level-Ground Walking","volume":"46","author":"Herr","year":"2009","journal-title":"J. Rehabil. Res. Dev."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Theeven, P.J., Hemmen, B., Brink, P.R., Smeets, R.J., and Seelen, H.A. (2013). Measures and Procedures Utilized to Determine the Added Value of Microprocessor-Controlled Prosthetic Knee Joints: A Systematic Review. BMC Musculoskelet. Disord., 14.","DOI":"10.1186\/1471-2474-14-333"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1682\/JRRD.2008.01.0007","article-title":"Differences in Function and Safety between Medicare Functional Classification Level-2 and -3 Transfemoral Amputees and Influence of Prosthetic Knee Joint Control","volume":"46","author":"Hafner","year":"2009","journal-title":"J. Rehabil. Res. Dev."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1016\/j.gaitpost.2016.11.015","article-title":"The Influence of a User-Adaptive Prosthetic Knee across Varying Walking Speeds: A Randomized Cross-Over Trial","volume":"51","author":"Prinsen","year":"2017","journal-title":"Gait Posture"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"343","DOI":"10.3727\/194982413X13844488879212","article-title":"The Effect of the C-Leg Knee Prosthesis on Sensory Dependency and Falls during Sensory Organization Testing","volume":"15","author":"Highsmith","year":"2014","journal-title":"Technol. Innov."},{"key":"ref_10","unstructured":"(2026, March 01). D\u00e1rigerler: Qazaqstanda Ayaq-Qoldy Amputaciyalaudyn Negizgi Sebepteri Ataldy. Available online: https:\/\/kaz.inform.kz\/news\/dargerler-kazakstanda-ayak-koldi-amputatsiyalaudin-negzg-sebeptern-atadi-b534fc\/."},{"key":"ref_11","unstructured":"(2026, March 01). Amputations of the Lower Extremity. Available online: https:\/\/clinicalpub.com\/amputations-of-the-lower-extremity\/."},{"key":"ref_12","unstructured":"(2026, March 01). Ministry of Labour and Social Protection of the Population of the Republic of Kazakhstan. Official Press Release, Available online: https:\/\/www.gov.kz\/memleket\/entities\/enbek-sko\/press\/news\/details\/435061."},{"key":"ref_13","unstructured":"(2026, March 01). Qansha Qazaqstandyqqa Protezdik-Ortopediyalyq K\u00f6mek K\u00f6rsetildi. Available online: https:\/\/mail.kz\/kz\/news\/kz-news\/kansha-kazakstandykka-protezdik-ortopediyalyk-komek-korsetildi."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Akhmejanov, S., Zhetenbayev, N., Sultan, A., Zhauyt, A., Nurgizat, Y., Ozhikenov, K., Ayazbay, A.-A., and Uzbekbayev, A. (2025). Design and Analysis of an Autonomous Active Ankle\u2013Foot Prosthesis with 2-DoF. Sensors, 25.","DOI":"10.3390\/s25164881"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/10\/3257\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T09:33:40Z","timestamp":1779356020000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/10\/3257"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,21]]},"references-count":14,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["s26103257"],"URL":"https:\/\/doi.org\/10.3390\/s26103257","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,21]]}}}