[ { "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: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: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" } ]