{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T11:14:57Z","timestamp":1783422897632,"version":"3.54.6"},"reference-count":44,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T00:00:00Z","timestamp":1782950400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000761","name":"Imperial College Confidence in Concept Grant","doi-asserted-by":"publisher","award":["P81130"],"award-info":[{"award-number":["P81130"]}],"id":[{"id":"10.13039\/501100000761","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000781","name":"ERC Synergy Project NaturalBionicS","doi-asserted-by":"publisher","award":["810346"],"award-info":[{"award-number":["810346"]}],"id":[{"id":"10.13039\/501100000781","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000266","name":"EPSRC Transformative Healthcare NISNEM Technology","doi-asserted-by":"publisher","award":["EP\/T020970\/1"],"award-info":[{"award-number":["EP\/T020970\/1"]}],"id":[{"id":"10.13039\/501100000266","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Background: We present a miniature (30 \u00d7 34 mm) 64-channel data acquisition headstage optimized for high-density surface electromyography. Methods: The headstage is made up of a multi-channel ASIC analogue front-end utilizing only MOS transistors, fabricated in 350 nm CMOS technology (IC die dimensions 6.9 \u00d7 1.8 mm), combined with an off-the-shelf multi-channel current-input ADC (DDC264, Texas Instruments). The ASIC analogue front-end employs MOS-based capacitors for both processing and AC-coupling. Results: The combination of these two sub-circuits enables the simultaneous recording of 64 channels at a typical sampling rate of 4 KHz with a maximum analogue bandwidth of 0.5\u20131500 Hz and a resolution of 20-bits. Typical input-referred-noise, determined by the analogue front-end, is 3.5 \u03bcVRMS for a surface EMG bandwidth of interest of 20\u2013500 Hz. This two-chip solution results in a power consumption of 5 mW per channel. Analogue performance variability of the custom ASIC was characterized across a dataset of 960-channels (15 dies) from two fabrication runs. Conclusions: This work practically demonstrates the viability of using both a MOS-only analogue front-end and commercially available off-shelf high-performance back-end hardware already developed for medical imaging applications to record high-density surface biosignals. The aforementioned techniques can be employed to reduce the size and cost for systems or wearable devices; facilitating the translation of high-density bio-acquisition setups from the research environment to more affordable commercial products.<\/jats:p>","DOI":"10.3390\/s26134181","type":"journal-article","created":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T11:48:32Z","timestamp":1782992912000},"page":"4181","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Design and Measured Assessment of a MOS-Only, Capacitorless, Miniature 64-Channel Headstage Circuit for High-Density Surface Electromyography"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6580-6932","authenticated-orcid":false,"given":"Simos","family":"Koutsoftidis","sequence":"first","affiliation":[{"name":"The Department of Bioengineering, Imperial College London, London SW7 2AZ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-9304-5111","authenticated-orcid":false,"given":"Georgios","family":"Gryparis","sequence":"additional","affiliation":[{"name":"The Department of Bioengineering, Imperial College London, London SW7 2AZ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5883-9306","authenticated-orcid":false,"given":"Maciej","family":"Zajaczkowski","sequence":"additional","affiliation":[{"name":"The Department of Bioengineering, Imperial College London, London SW7 2AZ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guang","family":"Yang","sequence":"additional","affiliation":[{"name":"The Department of Bioengineering, Imperial College London, London SW7 2AZ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Konstantinos","family":"Glaros","sequence":"additional","affiliation":[{"name":"The Department of Bioengineering, Imperial College London, London SW7 2AZ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7883-2697","authenticated-orcid":false,"given":"Dario","family":"Farina","sequence":"additional","affiliation":[{"name":"The Department of Bioengineering, Imperial College London, London SW7 2AZ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6649-0573","authenticated-orcid":false,"given":"Emmanuel M.","family":"Drakakis","sequence":"additional","affiliation":[{"name":"The Department of Bioengineering, Imperial College London, London SW7 2AZ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"102440","DOI":"10.1016\/j.jelekin.2020.102440","article-title":"Tutorial. Surface EMG detection, conditioning and pre-processing: Best practices","volume":"54","author":"Merletti","year":"2020","journal-title":"J. Electromyogr. Kinesiol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S1050-6411(01)00033-5","article-title":"Sampling, noise-reduction and amplitude estimation issues in surface electromyography","volume":"12","author":"Clancy","year":"2002","journal-title":"J. Electromyogr. Kinesiol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2101","DOI":"10.1088\/0967-3334\/35\/10\/2101","article-title":"A new method to assess skin treatments for lowering the impedance and noise of individual gelled Ag-AgCl electrodes","volume":"35","author":"Piervirgili","year":"2014","journal-title":"Physiol. Meas."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1002\/mus.10358","article-title":"Multichannel surface EMG: Basic aspects and clinical utility","volume":"28","author":"Zwarts","year":"2003","journal-title":"Muscle Nerve"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"353","DOI":"10.1109\/JPROC.2015.2498665","article-title":"Characterization of Human Motor Units from Surface EMG Decomposition","volume":"104","author":"Farina","year":"2016","journal-title":"Proc. IEEE"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"586","DOI":"10.1016\/j.jelekin.2006.09.005","article-title":"Clinical applications of high-density surface EMG: A systematic review","volume":"16","author":"Drost","year":"2006","journal-title":"J. Electromyogr. Kinesiol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Kapelner, T., Jiang, N., Holobar, A., Vujaklija, I., Roche, A.D., Farina, D., and Aszmann, O.C. (2016). Motor Unit Characteristics after Targeted Muscle Reinnervation. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0149772"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"36571","DOI":"10.1038\/srep36571","article-title":"Gesture recognition by instantaneous surface EMG images","volume":"6","author":"Geng","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1109\/TBCAS.2019.2955641","article-title":"A Fully Embedded Adaptive Real-Time Hand Gesture Classifier Leveraging HD-sEMG and Deep Learning","volume":"14","author":"Tam","year":"2020","journal-title":"IEEE Trans. Biomed. Circuits Syst."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"5834","DOI":"10.1038\/s41598-020-62773-7","article-title":"Neuro-Musculoskeletal Mapping for Man-Machine Interfacing","volume":"10","author":"Kapelner","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Barsakcioglu, D.Y., and Farina, D. (2018). A real-time surface EMG decomposition system for non-invasive human-machine interfaces. Proceedings of the 2018 IEEE Biomedical Circuits and Systems Conference (BioCAS), IEEE.","DOI":"10.1109\/BIOCAS.2018.8584659"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2641","DOI":"10.1109\/TII.2020.3001612","article-title":"Neuromuscular Password-Based User Authentication","volume":"17","author":"Jiang","year":"2021","journal-title":"IEEE Trans. Ind. Inform."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1109\/TBCAS.2020.3005148","article-title":"A Study of Personal Recognition Method Based on EMG Signal","volume":"14","author":"Lu","year":"2020","journal-title":"IEEE Trans. Biomed. Circuits Syst."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1109\/JSSC.2011.2163552","article-title":"A 0.013 mm2, 5 \u03bcW, DC-Coupled Neural Signal Acquisition IC with 0.5 V Supply","volume":"47","author":"Muller","year":"2012","journal-title":"IEEE J. Solid State Circuits"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Papadopoulou, A., Hermiz, J., Grace, C., and Denes, P. (2024). A Modular 512-Channel Neural Signal Acquisition ASIC for High-Density 4096 Channel Electrophysiology. Sensors, 24.","DOI":"10.36227\/techrxiv.21396978.v2"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"958","DOI":"10.1109\/JSSC.2003.811979","article-title":"A low-power low-noise CMOS amplifier for neural recording applications","volume":"38","author":"Harrison","year":"2003","journal-title":"IEEE J. Solid State Circuits"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1109\/JSSC.2017.2764053","article-title":"Modular 128-Channel \u0394-\u0394\u03a3 Analog Front-End Architecture Using Spectrum Equalization Scheme for 1024-Channel 3-D Neural Recording Microsystems","volume":"53","author":"Park","year":"2018","journal-title":"IEEE J. Solid State Circuits"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1109\/LSSC.2019.2916754","article-title":"A Chopper Stabilized, Current Feedback, Neural Recording Amplifier","volume":"2","author":"Samiei","year":"2019","journal-title":"IEEE Solid State Circuits Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3025","DOI":"10.1109\/JSSC.2008.2006462","article-title":"A 200 \u03bcW Eight-Channel EEG Acquisition ASIC for Ambulatory EEG Systems","volume":"43","author":"Yazicioglu","year":"2008","journal-title":"IEEE J. Solid State Circuits"},{"key":"ref_20","unstructured":"Intan Technologies (2012). RHD2000 Series Digital Electrophysiology Interface Chips Datasheet, Intan Technologies. Revised December 2023."},{"key":"ref_21","unstructured":"Texas Instruments (2010). Low-Power, 8-Channel, 16-Bit Analog Front-End for Biopotential Measurements Datasheet, Texas Instruments. Revised November 2011."},{"key":"ref_22","unstructured":"Texas Instruments (2006). DDC264 64-Channel, Current-Input Analog-to-Digital Converter Datasheet, Texas Instruments. Revised December 2016."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"026009","DOI":"10.1088\/1741-2552\/aa5a82","article-title":"A low-cost, scalable, current-sensing digital headstage for high channel count \u03bcECoG","volume":"14","author":"Trumpis","year":"2017","journal-title":"J. Neural Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"731","DOI":"10.1002\/cta.2254","article-title":"MOS-only reduced-order ELIN cochlear channels: Comparative performance evaluation","volume":"45","author":"Houssein","year":"2017","journal-title":"Int. J. Circuit Theory Appl."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Koutsoftidis, S., Belgaid, Y., Yang, G., Barsakcioglu, D.Y., Glaros, K.N., Farina, D., and Drakakis, E.M. (2024). A capacitorless, AC-coupled, monolithic input-stage optimized for multi-channel surface EMG acquisition. Proceedings of the 2024 46th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), IEEE.","DOI":"10.1109\/EMBC53108.2024.10782243"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Ghamati, M., and Maymandi-Nejad, M. (2013, January 14\u201316). A low-noise low-power MOSFET only electrocardiogram amplifier. Proceedings of the 2013 21st Iranian Conference on Electrical Engineering (ICEE), Mashhad, Iran.","DOI":"10.1109\/IranianCEE.2013.6599849"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Kuo, K.C., Chen, C.T., and Liao, H.Y. (2023, January 17\u201319). An Area Efficient Analog Front-End for Sensing EEG Signals with MOS Capacitors in 90nm Process. Proceedings of the 2023 International Conference on Consumer Electronics\u2014Taiwan (ICCE-Taiwan), Pingtung County, Taiwan.","DOI":"10.1109\/ICCE-Taiwan58799.2023.10226840"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"536","DOI":"10.1109\/JETCAS.2011.2178731","article-title":"An Area-Efficient Noise-Adaptive Neural Amplifier in 130 nm CMOS Technology","volume":"1","author":"Chaturvedi","year":"2011","journal-title":"IEEE J. Emerg. Sel. Top. Circuits Syst."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Kmon, P., Zoladz, M., Grybos, P., and Szczygiel, R. (2009). Design and measurements of 64-channel ASIC for neural signal recording. Proceedings of the 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE.","DOI":"10.1109\/IEMBS.2009.5333629"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1007\/BF02344216","article-title":"Investigation into the origin of the noise of surface electrodes","volume":"40","author":"Huigen","year":"2002","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Djekic, D., Ortmanns, M., Fantner, G., and Anders, J. (2016, January 22\u201325). A tunable, robust pseudo-resistor with enhanced linearity for scanning ion-conductance microscopy. Proceedings of the 2016 IEEE International Symposium on Circuits and Systems (ISCAS), Montreal, QC, Canada.","DOI":"10.1109\/ISCAS.2016.7527372"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2094","DOI":"10.1109\/JSSC.2020.2973639","article-title":"High-value tunable pseudo-resistors design","volume":"55","author":"Guglielmi","year":"2020","journal-title":"IEEE J. Solid State Circuits"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Trzpil-Jurgielewicz, B., D\u0105browski, W., and Hottowy, P. (2021). Analysis and Reduction of Nonlinear Distortion in AC-Coupled CMOS Neural Amplifiers with Tunable Cutoff Frequencies. Sensors, 21.","DOI":"10.3390\/s21093116"},{"key":"ref_34","unstructured":"Carusone, T.C., Johns, D.A., and Martin, K.W. (2013). Analog Integrated Circuit Design, Wiley. [2nd ed.]. International Student Version."},{"key":"ref_35","unstructured":"Texas Instruments (2014). REF19xx Low-Drift, Low-Power, Dual-Output, VREF and VREF\/2 Voltage References Datasheet, Texas Instruments. Revised January 2017."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Huang, Y.K., Schrunder, A.F., Rusu, A., and Rodriguez, S. (2024). A Frequency-Division Multiplexed 16-Channel AFE for Wearable MC-sEMG Recording. Proceedings of the 2024 31st IEEE International Conference on Electronics, Circuits and Systems (ICECS), IEEE.","DOI":"10.1109\/ICECS61496.2024.10848532"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"6582","DOI":"10.1109\/JSEN.2024.3523963","article-title":"A Low-Channel-Mismatch ExG AFE Based on Orthogonal Nested-Chopper and Successive-Approximation Input Capacitance Calibration","volume":"25","author":"Yin","year":"2025","journal-title":"IEEE Sens. J."},{"key":"ref_38","unstructured":"Chen, W.M., Yang, W.C., Tsai, T.Y., Chiueh, H., and Wu, C.Y. (2011). The design of CMOS general-purpose analog front-end circuit with tunable gain and bandwidth for biopotential signal recording systems. Proceedings of the 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1419","DOI":"10.1109\/TBCAS.2021.3131642","article-title":"Multi-Channel Biopotential Acquisition System Using Frequency-Division Multiplexing with Cable Motion Artifact Suppression","volume":"15","author":"Kim","year":"2021","journal-title":"IEEE Trans. Biomed. Circuits Syst."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2173","DOI":"10.1109\/TVLSI.2024.3430059","article-title":"A 370-nW Bio-AFE with 2.9-\u03bc Vrms Input Noise in an Octa-Channel System-in-Package for Multimode Bio-Signal Acquisition","volume":"32","author":"Fath","year":"2024","journal-title":"IEEE Trans. Very Large Scale Integr. (VLSI) Syst."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1043","DOI":"10.1109\/JSSC.2012.2185338","article-title":"HermesE: A 96-Channel Full Data Rate Direct Neural Interface in 0.13 \u03bc m CMOS","volume":"47","author":"Gao","year":"2012","journal-title":"IEEE J. Solid State Circuits"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1834","DOI":"10.1109\/TIM.2014.2299525","article-title":"Noise Reduction in AC-Coupled Amplifiers","volume":"63","year":"2014","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_43","unstructured":"Wang, J., Trumpis, M., Insanally, M., Froemke, R., and Viventi, J. (2014). A low-cost, multiplexed electrophysiology system for chronic \u03bcECoG recordings in rodents. Proceedings of the 2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE."},{"key":"ref_44","unstructured":"Texas Instruments (2012). ADS1299-x Low-Noise, 4-, 6-, 8-Channel, 24-Bit, Analog-to-Digital Converter for EEG and Biopotential Measurements Datasheet, Texas Instruments. Revised January 2017."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/13\/4181\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T10:25:45Z","timestamp":1783419945000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/13\/4181"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,2]]},"references-count":44,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["s26134181"],"URL":"https:\/\/doi.org\/10.3390\/s26134181","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,2]]}}}