[ { "id": "authors:vexp2-v8d31", "collection": "authors", "collection_id": "vexp2-v8d31", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150904-094021650", "type": "article", "title": "Reduced carbon emission estimates from fossil fuel\n combustion and cement production in China", "author": [ { "family_name": "Liu", "given_name": "Zhu", "orcid": "0000-0002-8968-7050", "clpid": "Liu-Zhu" }, { "family_name": "Guan", "given_name": "Dabo", "clpid": "Guan-Dabo" }, { "family_name": "Wei", "given_name": "Wei", "orcid": "0000-0002-1018-7708", "clpid": "Wei-Wei" }, { "family_name": "Davis", "given_name": "Steven J.", "orcid": "0000-0002-9338-0844", "clpid": "Davis-S-J" }, { "family_name": "Ciais", "given_name": "Philippe", "orcid": "0000-0001-8560-4943", "clpid": "Ciais-P" }, { "family_name": "Bai", "given_name": "Jin", "clpid": "Bai-Jin" }, { "family_name": "Peng", "given_name": "Shushi", "orcid": "0000-0001-5098-726X", "clpid": "Peng-Shushi" }, { "family_name": "Zhang", "given_name": "Qiang", "orcid": "0000-0002-8376-131X", "clpid": "Zhang-Qiang" }, { "family_name": "Hubacek", "given_name": "Klaus", "orcid": "0000-0003-2561-6090", "clpid": "Hubacek-K" }, { "family_name": "Garland", "given_name": "Gregg", "clpid": "Garland-G" }, { "family_name": "Andres", "given_name": "Robert J.", "clpid": "Andres-R-J" }, { "family_name": "Crawford-Brown", "given_name": "Douglas", "clpid": "Crawford-Brown-D" }, { "family_name": "Lin", "given_name": "Jintai", "clpid": "Lin-Jintai" }, { "family_name": "Zhao", "given_name": "Hongyan", "clpid": "Zhao-Hongyan" }, { "family_name": "Hong", "given_name": "Chaopeng", "clpid": "Hong-Chaopeng" }, { "family_name": "Boden", "given_name": "Thomas A.", "clpid": "Boden-T-A" }, { "family_name": "Feng", "given_name": "Kuishuang", "orcid": "0000-0001-5139-444X", "clpid": "Feng-Kuishuang" }, { "family_name": "Peters", "given_name": "Glen P.", "clpid": "Peters-G-P" }, { "family_name": "Xi", "given_name": "Fengming", "clpid": "Xi-Fengming" }, { "family_name": "Liu", "given_name": "Junguo", "clpid": "Liu-Junguo" }, { "family_name": "Li", "given_name": "Yuan", "clpid": "Lin-Yuan" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Zeng", "given_name": "Ning", "clpid": "Zeng-Ning" }, { "family_name": "He", "given_name": "Kevin", "orcid": "0000-0001-5806-0370", "clpid": "He-Kevin" } ], "abstract": "Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000\u20132012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO_2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = \u00b17.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000\u20132013 may be larger than China's estimated total forest sink in 1990\u20132007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000\u20132009 (2.6 gigatonnes of carbon).", "doi": "10.1038/nature14677", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2015-08-20", "series_number": "7565", "volume": "524", "issue": "7565", "pages": "335-338" }, { "id": "authors:yzfkj-g9w49", "collection": "authors", "collection_id": "yzfkj-g9w49", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160318-083235523", "type": "book_section", "title": "A Wireless EeG Recording System for Small Animal Models of Heart Regeneration", "book_title": "2015 IEEE MTT-S International Microwave Symposium", "author": [ { "family_name": "Cao", "given_name": "Hung", "clpid": "Cao-Hung" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Kouki", "given_name": "Ammar B.", "clpid": "Kouki-A-B" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" }, { "family_name": "Hsiai", "given_name": "Tzung K.", "orcid": "0000-0003-1734-0792", "clpid": "Hsiai-Tzung-K" } ], "abstract": "Heart failure afflicts the developed world, causing mortality more than any other diseases. This is due to the fact that humans' heart possesses a very limited capacity to regenerate. Heart attacks or myocardial infarction (MI) could result in an irreversible loss of cardiomyocytes and consequently heart failure. Besides, zebrafish and neonatal mice are well-known for their magical capacity to recover after ventricular amputation, thus becoming precious models for heart regeneration studies. In this work, we report the first wireless electrocardiography (ECG) recording system for small animal models of heart regeneration. The system consists of a microelectrode array (MEA) and electronic components for wireless powering, signal processing and data communication. The MEA is based on a biocompatible and flexible polymer so it could conform to non-planar anatomical surfaces. The power transfer is achieved using inductive coupling between two solenoids and the ECG signals are sent through an optical link. The wireless operation can free the animal, eliminating anesthesia during experiments and thus minimizing unwanted side effects. The first generation of the device was demonstrated successfully with neonatal mice, revealing awake ECG signals with all features, thereby paving the way to physiologically investigate heart regeneration in long-term without disrupting the animals' normal activities.", "doi": "10.1109/MWSYM.2015.7167081", "isbn": "978-1-4799-8275-2", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2015-05", "pages": "1-3" }, { "id": "authors:2sn1z-9ay67", "collection": "authors", "collection_id": "2sn1z-9ay67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150420-153441058", "type": "article", "title": "Dry-contact microelectrode membranes for wireless detection of electrical phenotypes in neonatal mouse hearts", "author": [ { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Cao", "given_name": "Hung", "clpid": "Cao-Hung" }, { "family_name": "Beebe", "given_name": "Tyler", "clpid": "Beebe-T" }, { "family_name": "Zhang", "given_name": "Hemin", "clpid": "Zhang-Hemin" }, { "family_name": "Zhang", "given_name": "Xiaoxiao", "clpid": "Zhang-Xiaoxiao" }, { "family_name": "Chang", "given_name": "Honglong", "clpid": "Chang-Honglong" }, { "family_name": "Scremin", "given_name": "Oscar", "clpid": "Scremin-O" }, { "family_name": "Lien", "given_name": "Ching-Ling", "clpid": "Lien-Ching-Ling" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" }, { "family_name": "Hsiai", "given_name": "Tzung K.", "orcid": "0000-0003-1734-0792", "clpid": "Hsiai-Tzung-K" } ], "abstract": "Continuous monitoring of aberrant electrical rhythms during heart injury and repair requires prolonged data acquisition. We hereby developed a wearable microelectrode membrane that could be adherent to the chest of neonatal mice for in situ wireless recording of electrocardiogram (ECG) signals. The novel dry-contact membrane with a meshed parylene-C pad adjacent to the microelectrodes and the expandable meandrous strips allowed for varying size of the neonates. The performance was evaluated at the system level; specifically, the ECG signals (\u03bcV) acquired from the microelectrodes underwent two-stage amplification, band-pass filtering, and optical data transmission by an infrared Light Emitting Diode (LED) to the data-receiving unit. The circuitry was prototyped on a printed circuit board (PCB), consuming less than 300 \u03bcW, and was completely powered by an inductive coupling link. Distinct P waves, QRS complexes, and T waves of ECG signals were demonstrated from the non-pharmacologically sedated neonates at ~600 beats per minutes. Thus, we demonstrate the feasibility of both real-time and wireless monitoring cardiac rhythms in a neonatal mouse (17\u201320 mm and <1 g) via dry-contact microelectrode membrane; thus, providing a basis for diagnosing aberrant electrical conduction in animal models of cardiac injury and repair.", "doi": "10.1007/s10544-014-9912-y", "issn": "1387-2176", "publisher": "Springer", "publication": "Biomedical Microdevices", "publication_date": "2015-04", "series_number": "2", "volume": "17", "issue": "2", "pages": "Art. No. 40" }, { "id": "authors:2ctm0-act93", "collection": "authors", "collection_id": "2ctm0-act93", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140902-083854858", "type": "article", "title": "Wearable multi-channel microelectrode membranes for elucidating electrophysiological phenotypes of injured myocardium", "author": [ { "family_name": "Cao", "given_name": "Hung", "clpid": "Cao-Hung" }, { "family_name": "Yu", "given_name": "Fei", "clpid": "Yu-Fei" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Zhang", "given_name": "Xiaoxiao", "clpid": "Zhang-Xiaoxiao" }, { "family_name": "Tai", "given_name": "Joyce", "clpid": "Tai-Joyce" }, { "family_name": "Lee", "given_name": "Juhyun", "clpid": "Lee-Juhyun" }, { "family_name": "Darehzerenski", "given_name": "Ali", "clpid": "Darehzereshki-A" }, { "family_name": "Bersohn", "given_name": "Malcolm", "clpid": "Bersohn-M" }, { "family_name": "Lien", "given_name": "Ching-Ling", "clpid": "Lien-Ching-Ling" }, { "family_name": "Chi", "given_name": "Neil C.", "clpid": "Chi-Neil-C" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" }, { "family_name": "Hsiai", "given_name": "Tzung K.", "orcid": "0000-0003-1734-0792", "clpid": "Hsiai-Tzung-K" } ], "abstract": "Understanding the regenerative capacity of small vertebrate models has provided new insights into the plasticity of injured myocardium. Here, we demonstrate the application of flexible microelectrode arrays (MEAs) in elucidating electrophysiological phenotypes of zebrafish and neonatal mouse models of heart regeneration. The 4-electrode MEA membranes were designed to detect electrical signals in the aquatic environment. They were micro-fabricated to adhere to the non-planar body surface of zebrafish and neonatal mice. The acquired signals were processed to display an electrocardiogram (ECG) with high signal-to-noise-ratios, and were validated via the use of conventional micro-needle electrodes. The 4-channel MEA provided signal stability and spatial resolution, revealing the site-specific electrical injury currents such as ST-depression in response to ventricular cryo-injury. Thus, our polymer-based and wearable MEA membranes provided electrophysiological insights into long-term conduction phenotypes for small vertebral models of heart injury and regeneration with a translational implication for monitoring cardiac patients.", "doi": "10.1039/c4ib00052h", "pmcid": "PMC4124744", "issn": "1757-9694", "publisher": "Royal Society of Chemistry", "publication": "Integrative Biology", "publication_date": "2014-08", "series_number": "8", "volume": "6", "issue": "8", "pages": "789-795" }, { "id": "authors:grxx3-tqk26", "collection": "authors", "collection_id": "grxx3-tqk26", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140425-092221534", "type": "article", "title": "Stretchable electrochemical impedance sensors for intravascular detection of lipid-rich lesions in New Zealand White rabbits", "author": [ { "family_name": "Cao", "given_name": "Hung", "clpid": "Cao-Hung" }, { "family_name": "Yu", "given_name": "Fei", "clpid": "Yu-Fei" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Scianmarello", "given_name": "Nick", "clpid": "Scianmarello-N" }, { "family_name": "Lee", "given_name": "Juhyun", "clpid": "Lee-Juhyun" }, { "family_name": "Dai", "given_name": "Wangde", "clpid": "Dai-Wangde" }, { "family_name": "Jen", "given_name": "Nelson", "clpid": "Jen-Nelson" }, { "family_name": "Beebe", "given_name": "Tyler", "clpid": "Beebe-T" }, { "family_name": "Li", "given_name": "Rongsong", "clpid": "Li-Rongsong" }, { "family_name": "Ebrahimi", "given_name": "Ramin", "clpid": "Ebrahimi-R" }, { "family_name": "Chang", "given_name": "Donald S.", "clpid": "Chang-Donald-S" }, { "family_name": "Mody", "given_name": "Freny V.", "clpid": "Mody-F-V" }, { "family_name": "Pacella", "given_name": "John", "clpid": "Pacella-J" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" }, { "family_name": "Hsiai", "given_name": "Tzung K.", "orcid": "0000-0003-1734-0792", "clpid": "Hsiai-Tzung-K" } ], "abstract": "Flexible electronics have enabled catheter-based intravascular sensing. However, real-time interrogation of unstable plaque remains an unmet clinical challenge. Here, we demonstrate the feasibility of stretchable electrochemical impedance spectroscopy (EIS) sensors for endoluminal investigations in New Zealand White (NZW) rabbits on diet-induced hyperlipidemia. A parylene C (PAC)-based EIS sensor mounted on the surface of an inflatable silicone balloon affixed to the tip of an interrogating catheter was deployed (1) on the explants of NZW rabbit aorta for detection of lipid-rich atherosclerotic lesions, and (2) on live animals for demonstration of balloon inflation and EIS measurements. An input peak-to-peak AC voltage of 10 mV and sweeping-frequency from 300 kHz to 100 Hz were delivered to the endoluminal sites. Balloon inflation allowed EIS sensors to be in contact with endoluminal surface. In the oxidized low-density-lipoprotein (oxLDL)-rich lesions from explants of fat-fed rabbits, impedance magnitude increased significantly by 1.5-fold across the entire frequency band, and phase shifted ~5\u00b0 at frequencies below 10 kHz. In the lesion-free sites of the normal diet-fed rabbits, impedance magnitude increased by 1.2-fold and phase shifted ~5\u00b0 at frequencies above 30 kHz. Thus, we demonstrate the feasibility of stretchable intravascular EIS sensors for identification of lipid rich lesions, with a translational implication for detecting unstable lesions.", "doi": "10.1016/j.bios.2013.11.059", "issn": "0956-5663", "publisher": "Elsevier", "publication": "Biosensors and Bioelectronics", "publication_date": "2014-04-15", "volume": "54", "pages": "610-616" }, { "id": "authors:k5kgc-jwy54", "collection": "authors", "collection_id": "k5kgc-jwy54", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140225-114331568", "type": "article", "title": "A Fully Intraocular High-Density Self-Calibrating Epiretinal Prosthesis", "author": [ { "family_name": "Monge", "given_name": "Manuel", "orcid": "0000-0001-9799-0693", "clpid": "Monge-Manuel" }, { "family_name": "Raj", "given_name": "Mayank", "clpid": "Raj-M" }, { "family_name": "Nazari", "given_name": "Meisam Honarvar", "clpid": "Nazari-M-H" }, { "family_name": "Chang", "given_name": "Han-Chieh", "clpid": "Chang-Han-Chieh" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Weiland", "given_name": "James D.", "clpid": "Weiland-J-D" }, { "family_name": "Humayun", "given_name": "Mark S.", "orcid": "0000-0002-5830-5208", "clpid": "Humayun-M-S" }, { "family_name": "Tai", "given_name": "Yu Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" }, { "family_name": "Emami", "given_name": "Azita", "orcid": "0000-0002-6945-9958", "clpid": "Emami-A" } ], "abstract": "This paper presents a fully intraocular self-calibrating epiretinal prosthesis with 512 independent channels in 65 nm CMOS. A novel digital calibration technique matches the biphasic currents of each channel independently while the calibration circuitry is shared among every 4 channels. Dual-band telemetry for power and data with on-chip rectifier and clock recovery reduces the number of off-chip components. The rectifier utilizes unidirectional switches to prevent reverse conduction loss in the power transistors and achieves an efficiency > 80%. The data telemetry implements a phase-shift keying (PSK) modulation scheme and supports data rates up to 20 Mb/s. The system occupies an area of 4.5 \u00d73.1 mm^2. It features a pixel size of 0.0169 mm^2 and arbitrary waveform generation per channel. In vitro measurements performed on a Pt/Ir concentric bipolar electrode in phosphate buffered saline (PBS) are presented. A statistical measurement over 40 channels from 5 different chips shows a current mismatch with \u03bc = 1.12 \u03bcA and \u03c3 = 0.53 \u03bcA. The chip is integrated with flexible MEMS origami coils and parylene substrate to provide a fully intraocular implant.", "doi": "10.1109/TBCAS.2014.2298334", "issn": "1932-4545", "publisher": "IEEE", "publication": "IEEE Transactions on Biomedical Circuits and Systems", "publication_date": "2013-12", "series_number": "6", "volume": "7", "issue": "6", "pages": "747-760" }, { "id": "authors:dfpgz-gmq53", "collection": "authors", "collection_id": "dfpgz-gmq53", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140520-134501570", "type": "book_section", "title": "A wearable percutaneous implant for long term zebrafish epicardial ECG recording", "book_title": "2013 Transducers & Eurosensors XXVII", "author": [ { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Yu", "given_name": "Fei", "clpid": "Yu-Fei" }, { "family_name": "Cao", "given_name": "Hung", "clpid": "Cao-Hung" }, { "family_name": "Chang", "given_name": "Honglong", "clpid": "Chang-Honglong" }, { "family_name": "Zhang", "given_name": "Xiaoxiao", "clpid": "Zhang-Xiaoxiao" }, { "family_name": "Hsiai", "given_name": "Tzung K.", "orcid": "0000-0003-1734-0792", "clpid": "Hsiai-Tzung-K" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" } ], "abstract": "Heart, as the least regenerative organ in human, can regenerate in zebrafish even after up to 20% ventricle amputation without forming any scar tissue. The Electrocardiogram (ECG) recorded from multiple fixed locations around the heart with high spatial resolution can elucidate changes in cardiac electric phenotypes of injured and regenerating tissues. Therefore, a wearable zebrafish harness with a percutaneous planar electrode array was designed, fabricated and properly positioned to uncover the electrical conduction phenotypes during the zebrafish heart regeneration. The recording circuitry and data processing have also been developed and customized, paving the way to the future underwater wireless long-term ECG recording in real time.", "doi": "10.1109/Transducers.2013.6626876", "isbn": "9781467359818", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-06", "pages": "756-759" }, { "id": "authors:27jc1-3s702", "collection": "authors", "collection_id": "27jc1-3s702", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130711-105746475", "type": "article", "title": "Implantable micro-Electrode Array for Long-term ECG Recording in Zebrafish", "author": [ { "family_name": "Cobo", "given_name": "Angelica Maria", "clpid": "Cobo-A-M" }, { "family_name": "Yu", "given_name": "Fei", "clpid": "Yu-Fei" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Gu", "given_name": "Jie", "clpid": "Gu-Jie" }, { "family_name": "Cao", "given_name": "Hung", "clpid": "Cao-Hung" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" }, { "family_name": "Hsiai", "given_name": "Tzung K.", "orcid": "0000-0003-1734-0792", "clpid": "Hsiai-Tzung-K" } ], "abstract": "Zebrafish is an emerging model for cardiac electromechanical coupling owing to\nits regenerative capacity after 20% ventricular amputation. We hereby developed a\nmicro-electrode array (MEA) for both long-term and real-time monitoring of\nzebrafish electrocardiogram (ECG) in response to injury and regeneration. The gold\nsputtered 5-lead MEA was formed on a parylene base by micro-fabrication\nprocesses (Fig. 1A). To test the MEA, we sedated Zebrafish in 0.04% tricaine\nmethanesulfonate, followed by a 2-mm-long horizontal incision at 0.5 mm\ncaudally to the heart. The MEA was embedded into the incision site so that the four\nworking electrodes (WE) were close to the heart and the reference electrode (RE)\npositioned on the fish body. The entire device was then secured by medical epoxy\n(Fig. 1B). The ECG signal recording was performed by connecting the MEA to a\ndifferential amplifier and a computer loaded with Labview. The signal was\nprocessed using wavelet transform and thresholding algorithm. The ECG obtained\nfrom the top working electrode is shown in Fig. 1C. The processed data were\ncomparable with ECG recorded by conventional electrodes in terms of signal-tonoise\nratio (SNR) and patterns. The implantable devices remained attached to\nzebrafish for several days, allowing for reliable long-term and multi-site\nrecordings for heart regeneration research.", "issn": "0892-6638", "publisher": "Federation of American Societies for Experimental Biology", "publication": "FASEB Journal", "publication_date": "2013-04", "volume": "27", "pages": "Art. No. 706.9" }, { "id": "authors:ay50a-hpk89", "collection": "authors", "collection_id": "ay50a-hpk89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-164509091", "type": "book_section", "title": "A fully intraocular 0.0169 mm^2/pixel 512-channel self-calibrating epiretinal prosthesis in 65nm CMOS", "book_title": "2013 IEEE International Solid-State Circuits Conference Digest of Technical Papers", "author": [ { "family_name": "Monge", "given_name": "Manuel", "orcid": "0000-0001-9799-0693", "clpid": "Monge-Manuel" }, { "family_name": "Raj", "given_name": "Mayank", "clpid": "Raj-M" }, { "family_name": "Honarvar-Nazari", "given_name": "Meisam", "clpid": "Honarvar-Nazari-M" }, { "family_name": "Chang", "given_name": "Han-Chieh", "clpid": "Chang-Han-Chieh" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Weiland", "given_name": "James", "clpid": "Weiland-J-D" }, { "family_name": "Humayun", "given_name": "Mark", "orcid": "0000-0002-5830-5208", "clpid": "Humayun-M-S" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" }, { "family_name": "Emami-Neyestanak", "given_name": "Azita", "orcid": "0000-0002-6945-9958", "clpid": "Emami-A" } ], "abstract": "Since their conception and success in human trials, the flexibility and spatial resolution of retinal prostheses have been of major interest. Clinical studies have revealed that hundreds of channels are needed to restore functional visual perception, and more sophisticated waveforms present advantages over biphasic pulses. Initial designs targeted stimulation current levels up to 1mA to ensure functionality. For such designs, an output compliance of >10V was required, and HV technologies were used at the expense of area and power consumption. Human clinical trials have recently shown that implanted electrodes present a stimulus threshold as low as 50\u03bcA. In addition, advances in implant technology promise close placement of electrode array and retinal tissue, which can further decrease the required current. Thus, highly scaled LV technologies can provide alternative means to reduce area and power, and to support hundreds of flexible independent channels for fully intraocular implants. In this paper, a self-calibrating 512-channel epiretinal prosthesis in 65nm CMOS is presented. It features dual-band telemetry for power and data, clock recovery, a 2-step calibration technique to match biphasic stimulation currents, and an independent arbitrary output waveform per channel. The implant integrates coils (power and data), IC, external capacitors and electrode array using a biocompatible parylene substrate, providing a fully intraocular solution.", "doi": "10.1109/ISSCC.2013.6487742", "isbn": "978-1-4673-4516-3", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-02", "pages": "296-297" }, { "id": "authors:ymwfe-01248", "collection": "authors", "collection_id": "ymwfe-01248", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130729-090047591", "type": "book_section", "title": "Packaging study for a 512-channel intraocular epiretinal implant", "book_title": "IEEE 26th International Conference on Micro Electro Mechanical Systems (MEMS)", "author": [ { "family_name": "Chang", "given_name": "Jay Han-Chieh", "clpid": "Chang-Jay-Han-Chieh" }, { "family_name": "Liu", "given_name": "Yang", "orcid": "0000-0002-8155-9134", "clpid": "Liu-Yang" }, { "family_name": "Kang", "given_name": "Dongyang", "clpid": "Kang-Dongyang" }, { "family_name": "Monge", "given_name": "Manuel", "orcid": "0000-0001-9799-0693", "clpid": "Monge-Manuel" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Yu", "given_name": "Chia-Chen", "clpid": "Yu-Chia-Chen" }, { "family_name": "Emami-Neyestanak", "given_name": "Azita", "orcid": "0000-0002-6945-9958", "clpid": "Emami-A" }, { "family_name": "Weiland", "given_name": "James", "clpid": "Weiland-J-D" }, { "family_name": "Humayun", "given_name": "Mark", "orcid": "0000-0002-5830-5208", "clpid": "Humayun-M-S" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" } ], "abstract": "Much effort has been put into developing multi-channel retinal prosthetic devices. Currently, even the most advanced prostheses do not have enough channels to provide vision to a desirable level. In this paper, we present a system design and a packaging scheme for a 512-channel intraocular epiretinal implant. Both a wireless power coil (with high transfer efficiency) and a data coil are included for this intraocular system. Simulation of the interference between coils is investigated and the results show that the two coils can be put in a co-planar fashion using two notch filters to minimize interference. The complete package is demonstrated with a mechanical model with a parylene-C flexible circuit board, i.e., parylene flex, to show the placement of the IC chips, discrete components, and coils. It also shows the final folded device after surgical insertion into an eye to save space. The feasibility of the proposed structure has been successfully tested in vivo. Experimentally, the maximum allowable pulling force is measured by a dynamic mechanical analysis (DMA) machine to be 8N, which provides a large safety margin for surgery.", "doi": "10.1109/MEMSYS.2013.6474428", "isbn": "978-1-4673-5654-1", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2013-01", "pages": "1045-1048" }, { "id": "authors:n763v-v3756", "collection": "authors", "collection_id": "n763v-v3756", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-114631007", "type": "book_section", "title": "High Performance 3-coil Wireless Power Transfer System for the\n 512-electrode Epiretinal Prosthesis", "book_title": "2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)", "author": [ { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Nandra", "given_name": "Mandheerej", "clpid": "Nandra-M" }, { "family_name": "Yu", "given_name": "Chia-Chen", "clpid": "Yu-Chia-Chen" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" } ], "abstract": "The next-generation retinal prostheses feature high image resolution and chronic implantation. These features demand the delivery of power as high as 100 mW to be wireless and efficient. A common solution is the 2-coil inductive power link, used by current retinal prostheses. This power link tends to include a larger-size extraocular receiver coil coupled to the external transmitter coil, and the receiver coil is connected to the intraocular electrodes through a trans-sclera trans-choroid cable. In the long-term implantation of the device, the cable may cause hypotony (low intraocular pressure) and infection. However, when a 2-coil system is constructed from a small-size intraocular receiver coil, the efficiency drops drastically which may induce over heat dissipation and electromagnetic field exposure. Our previous 2-coil system achieved only 7% power transfer. This paper presents a fully intraocular and highly efficient wireless power transfer system, by introducing another inductive coupling link to bypass the trans-sclera trans-choroid cable. With the specific equivalent load of our customized 512-electrode stimulator, the current 3-coil inductive link was measured to have the overall power transfer efficiency around 36%, with 1-inch separation in saline. The high efficiency will favorably reduce the heat dissipation and electromagnetic field exposure to surrounding human tissues. The effect of the eyeball rotation on the power transfer efficiency was investigated as well. The efficiency can still maintain 14.7% with left and right deflection of 30 degree during normal use. The surgical procedure for the coils' implantation into the porcine eye was also demonstrated.", "doi": "10.1109/EMBC.2012.6347503", "isbn": "978-1-4244-4119-8", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2012-08", "pages": "6583-6586" }, { "id": "authors:6hjfw-wad54", "collection": "authors", "collection_id": "6hjfw-wad54", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120417-091746701", "type": "article", "title": "Flexible microelectrode arrays to interface epicardial electrical signals with intracardial calcium transients in zebrafish hearts", "author": [ { "family_name": "Yu", "given_name": "Fei", "clpid": "Yu-Fei" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Gu", "given_name": "Jie", "clpid": "Gu-Jie" }, { "family_name": "Quigley", "given_name": "Katherine L.", "clpid": "Quigley-K-L" }, { "family_name": "Chi", "given_name": "Neil C.", "clpid": "Chi-Neil-C" }, { "family_name": "Tai", "given_name": "Yu-Chong", "orcid": "0000-0001-8529-106X", "clpid": "Tai-Yu-Chong" }, { "family_name": "Hsiai", "given_name": "Tzung K.", "orcid": "0000-0003-1734-0792", "clpid": "Hsiai-Tzung-K" } ], "abstract": "The zebrafish (Danio rerio) is an emerging genetic model for regenerative medicine. In humans, myocardial infarction results in the irreversible loss of cardiomyocytes. However, zebrafish hearts fully regenerate after a 20% ventricular resection, without either scarring or arrhythmias. To study this cardiac regeneration, we developed implantable flexible multi-microelectrode membrane arrays that measure the epicardial electrocardiogram signals of zebrafish in real-time. The microelectrode electrical signals allowed for a high level of both temporal and spatial resolution (~20 \u03bcm), and the signal to noise ratio of the epicardial ECG was comparable to that of surface electrode ECG (7.1 dB vs. 7.4 dB, respectively). Processing and analysis of the signals from the microelectrode array demonstrated distinct ECG signals: namely, atrial conduction (P waves), ventricular contraction (QRS), and ventricular repolarization (QT interval). The electrical signals were in synchrony with optically measured Calcium concentration gradients in terms of d[Ca^(2+)]/dt at both whole heart and tissue levels. These microelectrodes therefore provide a real-time analytical tool for monitoring conduction phenotypes of small vertebral animals with a high temporal and spatial resolution.", "doi": "10.1007/s10544-011-9612-9", "pmcid": "PMC3322508", "issn": "1387-2176", "publisher": "Springer", "publication": "Biomedical Microdevices", "publication_date": "2012-04", "series_number": "2", "volume": "14", "issue": "2", "pages": "357-366" }, { "id": "authors:2vzbk-4et24", "collection": "authors", "collection_id": "2vzbk-4et24", "cite_using_url": "https://authors.library.caltech.edu/records/2vzbk-4et24", "type": "article", "title": "Microfluidic patterning of nanoparticle monolayers", "author": [ { "family_name": "Chen", "given_name": "Zhen", "orcid": "0000-0003-1723-0251", "clpid": "Chen-Zhen" }, { "family_name": "Zhao", "given_name": "Yu", "clpid": "Zhao-Yu" }, { "family_name": "Wang", "given_name": "Wei", "clpid": "Wang-Wei" }, { "family_name": "Li", "given_name": "Zhihong", "clpid": "Li-Zhihong" } ], "abstract": "
\n
\n

A microfluidic technique was developed to pattern nanoparticle monolayer controllably in a tentative polydimethylsiloxane (PDMS) microchannel. It was found that nanoparticle monolayer could be achieved in a two-step fluidic process: nanoparticle sedimentation and DI water rinsing. When nanoparticle suspension flows through a tentative PDMS microchannel, the particles will settle down due to the gravity effect and the Brownian motion and be captured onto the amino-functionalized substrate via electrostatic attraction. Aggregation on the substrate followed by a necessary DI water rinsing transforms hill-like nanoparticle aggregates into monolayer. Removing the tentative PDMS microchannel, pattern of nanoparticle monolayer following the channel shape was obtained. Experimental results indicated that the final monolayered nanoparticle coverage decreases when the flowing velocity in the sedimentation and/or the rinsing steps increases. Based on the continuity essence of fluid flow, different flowing velocities could be realized in one microchannel by varying the channel size. Therefore, monolayer patterns with controllable coverage could be achieved by carefully designing the microchannel width. The present approach is believed to be a promising nanoparticle monolayer patterning technique.

\n
\n
\n\n
\n
\n
", "doi": "10.1007/s10404-009-0420-y", "issn": "1613-4982", "publisher": "Springer Science and Business Media LLC", "publication": "Microfluidics and Nanofluidics", "publication_date": "2009-10", "series_number": "4", "volume": "7", "issue": "4", "pages": "585-591" } ]