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Williams RP, Karzova MM, Yuldashev PV, Kaloev AZ, Nartov FA, Khokhlova VA, Cunitz BW, Morrison KP, Khokhlova TD. Dual-Mode 1-D Linear Ultrasound Array for Image-Guided Drug Delivery Enhancement Without Ultrasound Contrast Agents. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:693-707. [PMID: 37074881 PMCID: PMC10712801 DOI: 10.1109/tuffc.2023.3268603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Pulsed high-intensity focused ultrasound (pHIFU) uses nonlinearly distorted millisecond-long ultrasound pulses of moderate intensity to induce inertial cavitation in tissue without administration of contrast agents. The resulting mechanical disruption permeabilizes the tissue and enhances the diffusion of systemically administered drugs. This is especially beneficial for tissues with poor perfusion such as pancreatic tumors. Here, we characterize the performance of a dual-mode ultrasound array designed for image-guided pHIFU therapies in producing inertial cavitation and ultrasound imaging. The 64-element linear array (1.071 MHz, an aperture of 14.8×51.2 mm, and a pitch of 0.8 mm) with an elevational focal length of 50 mm was driven by the Verasonics V-1 ultrasound system with extended burst option. The attainable focal pressures and electronic steering range in linear and nonlinear operating regimes (relevant to pHIFU treatments) were characterized through hydrophone measurements, acoustic holography, and numerical simulations. The steering range at ±10% from the nominal focal pressure was found to be ±6 mm axially and ±11 mm azimuthally. Focal waveforms with shock fronts of up to 45 MPa and peak negative pressures up to 9 MPa were achieved at focusing distances of 38-75 mm from the array. Cavitation behaviors induced by isolated 1-ms pHIFU pulses in optically transparent agarose gel phantoms were observed by high-speed photography across a range of excitation amplitudes and focal distances. For all focusing configurations, the appearance of sparse, stationary cavitation bubbles occurred at the same P- threshold of 2 MPa. As the output level increased, a qualitative change in cavitation behavior occurred, to pairs and sets of proliferating bubbles. The pressure P- at which this transition was observed corresponded to substantial nonlinear distortion and shock formation in the focal region and was thus dependent on the focal distance of the beam ranging within 3-4 MPa for azimuthal F -numbers of 0.74-1.5. The array was capable of B-mode imaging at 1.5 MHz of centimeter-sized targets in phantoms and in vivo pig tissues at depths of 3-7 cm, relevant to pHIFU applications in abdominal targets.
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Bilchick KC, Morgounova E, Oomen P, Malhotra R, Mason PK, Mangrum M, Kim D, Gao X, Darby AE, Monfredi OJ, Aso JA, Franzen PM, Stadler RW. First-in-human noninvasive left ventricular ultrasound pacing: A potential screening tool for cardiac resynchronization therapy. Heart Rhythm O2 2023; 4:79-87. [PMID: 36873311 PMCID: PMC9975015 DOI: 10.1016/j.hroo.2022.10.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Background A screening tool to predict response to cardiac resynchronization therapy (CRT) could improve patient selection and outcomes. Objective The purpose of this study was to investigate the feasibility and safety of noninvasive CRT via transcutaneous ultrasonic left ventricular (LV) pacing applied as a screening test before CRT implants. Methods P-wave-triggered ultrasound stimuli were delivered during bolus dosing of an echocardiographic contrast agent to simulate CRT noninvasively. Ultrasound pacing was delivered at a variety of LV locations with a range of atrioventricular delays to achieve fusion with intrinsic ventricular activation. Three-dimensional cardiac activation maps were acquired via the Medtronic CardioInsight 252-electrode mapping vest during baseline, ultrasound pacing, and after CRT implantation. A separate control group received only the CRT implants. Results Ultrasound pacing was achieved in 10 patients with a mean of 81.2 ± 50.8 ultrasound paced beats per patient and up to 20 consecutive beats of ultrasound pacing. QRS width at baseline (168.2 ± 17.8 ms) decreased significantly to 117.3 ± 21.5 ms (P <.001) in the best ultrasound paced beat and to 125.8 ± 13.3 ms (P <.001) in the best CRT beat. Electrical activation patterns were similar between CRT pacing and ultrasound pacing with stimulation from the same area of the LV. Troponin results were similar between the ultrasound pacing and the control groups (P = .96), confirming safety. Conclusion Noninvasive ultrasound pacing before CRT is safe and feasible, and it estimates the degree of electrical resynchronization achievable with CRT. Further study of this promising technique to guide CRT patient selection is warranted.
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Affiliation(s)
| | | | - Pim Oomen
- University of California Irvine, Irvine, California
| | - Rohit Malhotra
- University of Virginia Health System, Charlottesville, Virginia
| | - Pamela K Mason
- University of Virginia Health System, Charlottesville, Virginia
| | - Mike Mangrum
- University of Virginia Health System, Charlottesville, Virginia
| | - David Kim
- University of Virginia Health System, Charlottesville, Virginia
| | - Xu Gao
- Northwestern Medicine, Chicago, Illinois
| | - Andrew E Darby
- University of Virginia Health System, Charlottesville, Virginia
| | | | - Joy A Aso
- Medtronic plc, Mounds View, Minnesota
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Ditac G, Bessière F, Lafon C. Therapeutic ultrasound applications in cardiovascular diseases: a review. Ing Rech Biomed 2022. [DOI: 10.1016/j.irbm.2022.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Coiado OC, Yerrabelli RS, Christensen AP, Wozniak M, Lucas A, O'Brien WD. Positive chronotropic effect caused by transthoracic ultrasound in heart of rats. JASA EXPRESS LETTERS 2021; 1:082001. [PMID: 34396365 PMCID: PMC8340500 DOI: 10.1121/10.0005764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Pulsed ultrasound can produce chronotropic and inotropic effects on the heart with potential therapeutic applications. Fourteen 3-month-old female rats were exposed transthoracically to 3.5-MHz 2.0-MPa peak rarefactional pressure amplitude ultrasonic pulses of increasing 5-s duration pulse repetition frequency (PRF) sequences. An increase in the heart rate was observed following each PRF sequence: an ∼50% increase after the 4-5-6 Hz sequence, an ∼57% increase after the 5-6-7 Hz sequence, and an ∼48% increase after the 6-7-8 Hz sequence. Other cardiac parameters showed a normal or indicated a compensatory decrease at 3 and 15 min post-ultrasound compared to control.
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Affiliation(s)
- Olivia C Coiado
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Champaign, Illinois 61820, USA
| | - Rahul S Yerrabelli
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Champaign, Illinois 61820, USA
| | - Anton P Christensen
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Champaign, Illinois 61820, USA
| | - Marcin Wozniak
- Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 306 North Wright Street, Urbana, Illinois 61801, USA , , , , ,
| | - Alex Lucas
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Champaign, Illinois 61820, USA
| | - William D O'Brien
- Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 306 North Wright Street, Urbana, Illinois 61801, USA , , , , ,
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Messas E, Rémond MC, Goudot G, Zarka S, Penot R, Mateo P, Kwiecinski W, Escudero DS, Bel A, Ialy-Radio N, Bertrand B, Bruneval P, Marijon E, Spaargaren R, Tanter M, Pernot M. Feasibility and safety of non-invasive ultrasound therapy (NIUT) on an porcine aortic valve. Phys Med Biol 2020; 65:215004. [PMID: 33104523 DOI: 10.1088/1361-6560/aba6d3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Calcific aortic stenosis (CAS) is associated with advanced age and comorbidities, therefore a non-invasive therapy for it would be beneficial. We previously demonstrated that ultrasound therapy improved calcified bioprosthetic valve function in an open chest model. For translational applications, we tested non-invasive ultrasound therapy (NIUT) transthoracically on swine aortic valves and investigated the need for antithrombotic treatment as a follow-up. Primary objective: feasibility and safety of NIUT. Secondary objectives: occurrence, severity and evolution of side effects during therapy and at 1 month follow-up. The device (Valvosoft, Cardiawave) consisted of an electronically steered multi-element transducer and a 2D echocardiographic probe. Three groups of swine received treatment on aortic valves: NIUT (group 1; n = 10); NIUT and 1 month antithrombotic treatment (group 2; n = 5); sham group (group 3; n = 4). Feasibility was successfully reached in all treated swine (n = 15) and no life-threatening arrhythmia were detected. Non-sustained ventricular tachycardia occurred during the procedure in seven swine. Decrease or interruption of NIUT ended arrhythmia. Histopathology revealed no valve or surrounding tissue damage and echocardiography revealed no valvular dysfunction. Only one animal had side effects [right ventricle (RV) dilatation], but the RV normalized after therapy cessation with no sequelae at follow-up. No disturbance in biological markers nor valve thrombosis were observed at follow-up. Antithrombotic treatment did not demonstrate any advantage. Survival at 30 d was 100%. We demonstrated, in vivo, the feasibility and safety of transthoracic NIUT on aortic valves in a swine model without serious adverse events. We expect this first-time transthoracic delivery of NIUT to pave the way towards a new non-invasive approach to valve softening in human CAS to restore valve function.
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Affiliation(s)
- Emmanuel Messas
- Cardio-Vascular Departement, Hôpital Européen Georges Pompidou, Université of Paris, UMR 970, Paris, France. French Research Consortium STOP-AS, supported by the French Government, managed by the National Research Agency (ANR) under the program 'Investissements d'Avenir' with the reference ANR-16-RHUS-003, Rouen, France. These authors contributed equally to this work. Author to whom any correspondence should be addressed
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Quinn TA, Kohl P. Cardiac Mechano-Electric Coupling: Acute Effects of Mechanical Stimulation on Heart Rate and Rhythm. Physiol Rev 2020; 101:37-92. [PMID: 32380895 DOI: 10.1152/physrev.00036.2019] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The heart is vital for biological function in almost all chordates, including humans. It beats continually throughout our life, supplying the body with oxygen and nutrients while removing waste products. If it stops, so does life. The heartbeat involves precise coordination of the activity of billions of individual cells, as well as their swift and well-coordinated adaption to changes in physiological demand. Much of the vital control of cardiac function occurs at the level of individual cardiac muscle cells, including acute beat-by-beat feedback from the local mechanical environment to electrical activity (as opposed to longer term changes in gene expression and functional or structural remodeling). This process is known as mechano-electric coupling (MEC). In the current review, we present evidence for, and implications of, MEC in health and disease in human; summarize our understanding of MEC effects gained from whole animal, organ, tissue, and cell studies; identify potential molecular mediators of MEC responses; and demonstrate the power of computational modeling in developing a more comprehensive understanding of ‟what makes the heart tick.ˮ.
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Affiliation(s)
- T Alexander Quinn
- Department of Physiology and Biophysics and School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada; Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Medical Faculty of the University of Freiburg, Freiburg, Germany; and CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Peter Kohl
- Department of Physiology and Biophysics and School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada; Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Medical Faculty of the University of Freiburg, Freiburg, Germany; and CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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7
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Downs ME, Lee SA, Yang G, Kim S, Wang Q, Konofagou EE. Non-invasive peripheral nerve stimulation via focused ultrasound in vivo. Phys Med Biol 2018; 63:035011. [PMID: 29214985 DOI: 10.1088/1361-6560/aa9fc2] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Focused ultrasound (FUS) has been employed on a wide range of clinical applications to safely and non-invasively achieve desired effects that have previously required invasive and lengthy procedures with conventional methods. Conventional electrical neuromodulation therapies that are applied to the peripheral nervous system (PNS) are invasive and/or non-specific. Recently, focused ultrasound has demonstrated the ability to modulate the central nervous system and ex vivo peripheral neurons. Here, for the first time, noninvasive stimulation of the sciatic nerve eliciting a physiological response in vivo is demonstrated with FUS. FUS was applied on the sciatic nerve in mice with simultaneous electromyography (EMG) on the tibialis anterior muscle. EMG signals were detected during or directly after ultrasound stimulation along with observable muscle contraction of the hind limb. Transecting the sciatic nerve downstream of FUS stimulation eliminated EMG activity during FUS stimulation. Peak-to-peak EMG response amplitudes and latency were found to be comparable to conventional electrical stimulation methods. Histology along with behavioral and thermal testing did not indicate damage to the nerve or surrounding regions. The findings presented herein demonstrate that FUS can serve as a targeted, safe and non-invasive alternative to conventional peripheral nervous system stimulation to treat peripheral neuropathic diseases in the clinic.
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Affiliation(s)
- Matthew E Downs
- Departments of Biomedical Engineering, Columbia University, New York, NY 10032, United States of America
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Quinn TA, Kohl P. Comparing maximum rate and sustainability of pacing by mechanical vs. electrical stimulation in the Langendorff-perfused rabbit heart. Europace 2017; 18:iv85-iv93. [PMID: 28011835 PMCID: PMC5400084 DOI: 10.1093/europace/euw354] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 07/01/2016] [Indexed: 01/04/2023] Open
Abstract
Aims Mechanical stimulation (MS) represents a readily available, non-invasive means of pacing the asystolic or bradycardic heart in patients, but benefits of MS at higher heart rates are unclear. Our aim was to assess the maximum rate and sustainability of excitation by MS vs. electrical stimulation (ES) in the isolated heart under normal physiological conditions. Methods and results Trains of local MS or ES at rates exceeding intrinsic sinus rhythm (overdrive pacing; lowest pacing rates 2.5±0.5 Hz) were applied to the same mid-left ventricular free-wall site on the epicardium of Langendorff-perfused rabbit hearts. Stimulation rates were progressively increased, with a recovery period of normal sinus rhythm between each stimulation period. Trains of MS caused repeated focal ventricular excitation from the site of stimulation. The maximum rate at which MS achieved 1:1 capture was lower than during ES (4.2±0.2 vs. 5.9±0.2 Hz, respectively). At all overdrive pacing rates for which repetitive MS was possible, 1:1 capture was reversibly lost after a finite number of cycles, even though same-site capture by ES remained possible. The number of MS cycles until loss of capture decreased with rising stimulation rate. If interspersed with ES, the number of MS to failure of capture was lower than for MS only. Conclusion In this study, we demonstrate that the maximum pacing rate at which MS can be sustained is lower than that for same-site ES in isolated heart, and that, in contrast to ES, the sustainability of successful 1:1 capture by MS is limited. The mechanism(s) of differences in MS vs. ES pacing ability, potentially important for emergency heart rhythm management, are currently unknown, thus warranting further investigation.
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Affiliation(s)
- T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, 5850 College St, Halifax, NS B3H 4R2, Canada
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Medical School of the University of Freiburg, Elsaesser Str 2Q, 79110 Freiburg, Germany.,National Heart and Lung Institute, Imperial College London, The Magdi Yacoub Institute, Hill End Road, UB9 6JH London, UK
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9
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Nagarajan N, Vyas V, Huey BD, Zorlutuna P. Modulation of the contractility of micropatterned myocardial cells with nanoscale forces using atomic force microscopy. Nanobiomedicine (Rij) 2016; 3:1849543516675348. [PMID: 29942390 PMCID: PMC5998274 DOI: 10.1177/1849543516675348] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 08/29/2016] [Indexed: 11/16/2022] Open
Abstract
The ability to modulate cardiomyocyte contractility is important for bioengineering applications ranging from heart disease treatments to biorobotics. In this study, we examined the changes in contraction frequency of neonatal rat cardiomyocytes upon single-cell-level nanoscale mechanical stimulation using atomic force microscopy. To measure the response of same density of cells, they were micropatterned into micropatches of fixed geometry. To examine the effect of the substrate stiffness on the behavior of cells, they were cultured on a stiffer and a softer surface, glass and poly (dimethylsiloxane), respectively. Upon periodic cyclic stimulation of 300 nN at 5 Hz, a significant reduction in the rate of synchronous contraction of the cell patches on poly(dimethylsiloxane) substrates was observed with respect to their spontaneous beat rate, while the cell patches on glass substrates maintained or increased their contraction rate after the stimulation. On the other hand, single cells mostly maintained their contraction rate and could only withstand a lower magnitude of forces compared to micropatterned cell patches. This study reveals that the contraction behavior of cardiomyocytes can be modulated mechanically through cyclic nanomechanical stimulation, and the degree and mode of this modulation depend on the cell connectivity and substrate mechanical properties.
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Affiliation(s)
- Neerajha Nagarajan
- Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN, USA
| | - Varun Vyas
- Institute of Materials Science, University of Connecticut, Storrs, CT, USA
| | - Bryan D Huey
- Institute of Materials Science, University of Connecticut, Storrs, CT, USA.,Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, USA
| | - Pinar Zorlutuna
- Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN, USA.,Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN, USA
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10
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Non-invasive cardiac pacing with image-guided focused ultrasound. Sci Rep 2016; 6:36534. [PMID: 27827415 PMCID: PMC5101517 DOI: 10.1038/srep36534] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 10/17/2016] [Indexed: 11/11/2022] Open
Abstract
Currently, no non-invasive cardiac pacing device acceptable for prolonged use in conscious patients exists. High Intensity Focused Ultrasound (HIFU) can be used to perform remote pacing using reversibility of electromechanical coupling of cardiomyocytes. Here we described an extracorporeal cardiac stimulation device and study its efficacy and safety. We conducted experiments ex vivo and in vivo in a large animal model (pig) to evaluate clinical potential of such a technique. The stimulation threshold was determined in 10 different ex vivo hearts and different clinically relevant electrical effects such as consecutive stimulations of different heart chambers with a single ultrasonic probe, continuous pacing or the inducibility of ventricular tachycardia were shown. Using ultrasonic contrast agent, consistent cardiac stimulation was achievable in vivo for up to 1 hour sessions in 4 different animals. No damage was observed in inversion-recovery MR sequences performed in vivo in the 4 animals. Histological analysis revealed no differences between stimulated and control regions, for all ex vivo and in vivo cases.
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11
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Kohut AR, Vecchio C, Adam D, Lewin PA. The potential of ultrasound in cardiac pacing and rhythm modulation. Expert Rev Med Devices 2016; 13:815-22. [DOI: 10.1080/17434440.2016.1217772] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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12
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Abstract
Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field's foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.
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Affiliation(s)
- Omer Naor
- Department of Biomedical Engineering, The Technion-Israel Institute of Technology Haifa 32000, Israel. The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem 91220, Israel
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13
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Rotenberg MY, Gabay H, Etzion Y, Cohen S. Feasibility of Leadless Cardiac Pacing Using Injectable Magnetic Microparticles. Sci Rep 2016; 6:24635. [PMID: 27091192 PMCID: PMC4876985 DOI: 10.1038/srep24635] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 04/01/2016] [Indexed: 12/11/2022] Open
Abstract
A noninvasive, effective approach for immediate and painless heart pacing would have invaluable implications in several clinical scenarios. Here we present a novel strategy that utilizes the well-known mechano-electric feedback of the heart to evoke cardiac pacing, while relying on magnetic microparticles as leadless mechanical stimulators. We demonstrate that after localizing intravenously-injected magnetic microparticles in the right ventricular cavity using an external electromagnet, the application of magnetic pulses generates mechanical stimulation that provokes ventricular overdrive pacing in the rat heart. This temporary pacing consistently managed to revert drug-induced bradycardia, but could only last up to several seconds in the rat model, most likely due to escape of the particles between the applied pulses using our current experimental setting. In a pig model with open chest, MEF-based pacing was induced by banging magnetic particles and has lasted for a longer time. Due to overheating of the electromagnet, we intentionally terminated the experiments after 2 min. Our results demonstrate for the first time the feasibility of external leadless temporary pacing, using injectable magnetic microparticles that are manipulated by an external electromagnet. This new approach can have important utilities in clinical settings in which immediate and painless control of cardiac rhythm is required.
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Affiliation(s)
- Menahem Y. Rotenberg
- The Avram and Stella Goldstein-Goren Department of Biotechnology
Engineering, Ben-Gurion University of the Negev, Beer-Sheva,
Israel
| | - Hovav Gabay
- Cardiac Arrhythmia Research Laboratory, Department of Physiology
and Cell Biology, Ben-Gurion University of the Negev,
Beer-Sheva, Israel
| | - Yoram Etzion
- Cardiac Arrhythmia Research Laboratory, Department of Physiology
and Cell Biology, Ben-Gurion University of the Negev,
Beer-Sheva, Israel
- Regenerative Medicine & Stem Cell Research Center,
Ben-Gurion University of the Negev, Beer-Sheva,
Israel
| | - Smadar Cohen
- The Avram and Stella Goldstein-Goren Department of Biotechnology
Engineering, Ben-Gurion University of the Negev, Beer-Sheva,
Israel
- Regenerative Medicine & Stem Cell Research Center,
Ben-Gurion University of the Negev, Beer-Sheva,
Israel
- Ilse Katz Institute for Nanoscale Science and Technology,
Ben-Gurion University of the Negev, Beer-Sheva,
Israel
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Fleischman A, Vecchio C, Sunny Y, Bawiec CR, Lewin PA, Kresh JY, Kohut AR. Ultrasound-induced modulation of cardiac rhythm in neonatal rat ventricular cardiomyocytes. J Appl Physiol (1985) 2015; 118:1423-8. [PMID: 25858493 DOI: 10.1152/japplphysiol.00980.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 04/02/2015] [Indexed: 11/22/2022] Open
Abstract
Isolated neonatal rat ventricular cardiomyocytes were used to study the influence of ultrasound on the chronotropic response in a tissue culture model. The beat frequency of the cells, varying from 40 to 90 beats/min, was measured based upon the translocation of the nuclear membrane captured by a high-speed camera. Ultrasound pulses (frequency = 2.5 MHz) were delivered at 300-ms intervals [3.33 Hz pulse repetition frequency (PRF)], in turn corresponding to 200 pulses/min. The intensity of acoustic energy and pulse duration were made variable, 0.02-0.87 W/cm(2) and 1-5 ms, respectively. In 57 of 99 trials, there was a noted average increase in beat frequency of 25% with 8-s exposures to ultrasonic pulses. Applied ultrasound energy with a spatial peak time average acoustic intensity (Ispta) of 0.02 W/cm(2) and pulse duration of 1 ms effectively increased the contraction rate of cardiomyocytes (P < 0.05). Of the acoustic power tested, the lowest level of acoustic intensity and shortest pulse duration proved most effective at increasing the electrophysiological responsiveness and beat frequency of cardiomyocytes. Determining the optimal conditions for delivery of ultrasound will be essential to developing new models for understanding mechanoelectrical coupling (MEC) and understanding novel nonelectrical pacing modalities for clinical applications.
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Affiliation(s)
| | - Christopher Vecchio
- School of Biomedical Engineering, Science & Health System, Drexel University, Philadelphia, Pennsylvania; and
| | - Youhan Sunny
- School of Biomedical Engineering, Science & Health System, Drexel University, Philadelphia, Pennsylvania; and
| | - Christopher R Bawiec
- School of Biomedical Engineering, Science & Health System, Drexel University, Philadelphia, Pennsylvania; and
| | - Peter A Lewin
- School of Biomedical Engineering, Science & Health System, Drexel University, Philadelphia, Pennsylvania; and
| | - J Yasha Kresh
- Department of Medicine, School of Medicine and School of Biomedical Engineering, Science & Health System, Drexel University, Philadelphia, Pennsylvania; and Department of Cardiothoracic Surgery, School of Medicine School of Medicine and Drexel University, Philadelphia, Pennsylvania
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Abstract
Ultrasound therapy has been investigated for over half a century. Ultrasound can act on tissue through a variety of mechanisms, including thermal, shockwave and cavitation mechanisms, and through these can elicit different responses. Ultrasound therapy can provide a non-invasive or minimally invasive treatment option, and ultrasound technology has advanced to the point where devices can be developed to investigate a wide range of applications. This review focuses on non-cancer clinical applications of therapeutic ultrasound, with an emphasis on treatments that have recently reached clinical investigations, and preclinical research programmes that have great potential to impact patient care.
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Kohl P, Quinn TA. Novel technologies as drivers of progress in cardiac biophysics. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 115:69-70. [PMID: 25193876 DOI: 10.1016/j.pbiomolbio.2014.08.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Peter Kohl
- National Heart and Lung Institute, Imperial College London, UK; Department of Computer Science, University of Oxford, UK.
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Canada
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17
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Solovyova O, Katsnelson LB, Konovalov PV, Kursanov AG, Vikulova NA, Kohl P, Markhasin VS. The cardiac muscle duplex as a method to study myocardial heterogeneity. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 115:115-28. [PMID: 25106702 PMCID: PMC4210666 DOI: 10.1016/j.pbiomolbio.2014.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 07/25/2014] [Indexed: 12/14/2022]
Abstract
This paper reviews the development and application of paired muscle preparations, called duplex, for the investigation of mechanisms and consequences of intra-myocardial electro-mechanical heterogeneity. We illustrate the utility of the underlying combined experimental and computational approach for conceptual development and integration of basic science insight with clinically relevant settings, using previously published and new data. Directions for further study are identified.
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Affiliation(s)
- O Solovyova
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia; Ural Federal University, 19 Mira Str, Ekaterinburg 620002, Russia.
| | - L B Katsnelson
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia
| | - P V Konovalov
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia
| | - A G Kursanov
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia; Ural Federal University, 19 Mira Str, Ekaterinburg 620002, Russia
| | - N A Vikulova
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia
| | - P Kohl
- National Heart and Lung Institute, Imperial College of London, Heart Science Centre, Harefield Hospital, Hill End Road, Harefield UB9 6JH, UK; Department of Computer Sciences, University of Oxford, UK
| | - V S Markhasin
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia; Ural Federal University, 19 Mira Str, Ekaterinburg 620002, Russia
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18
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Ambrosi CM, Klimas A, Yu J, Entcheva E. Cardiac applications of optogenetics. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 115:294-304. [PMID: 25035999 DOI: 10.1016/j.pbiomolbio.2014.07.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 07/05/2014] [Indexed: 01/16/2023]
Abstract
In complex multicellular systems, such as the brain or the heart, the ability to selectively perturb and observe the response of individual components at the cellular level and with millisecond resolution in time, is essential for mechanistic understanding of function. Optogenetics uses genetic encoding of light sensitivity (by the expression of microbial opsins) to provide such capabilities for manipulation, recording, and control by light with cell specificity and high spatiotemporal resolution. As an optical approach, it is inherently scalable for remote and parallel interrogation of biological function at the tissue level; with implantable miniaturized devices, the technique is uniquely suitable for in vivo tracking of function, as illustrated by numerous applications in the brain. Its expansion into the cardiac area has been slow. Here, using examples from published research and original data, we focus on optogenetics applications to cardiac electrophysiology, specifically dealing with the ability to manipulate membrane voltage by light with implications for cardiac pacing, cardioversion, cell communication, and arrhythmia research, in general. We discuss gene and cell delivery methods of inscribing light sensitivity in cardiac tissue, functionality of the light-sensitive ion channels within different types of cardiac cells, utility in probing electrical coupling between different cell types, approaches and design solutions to all-optical electrophysiology by the combination of optogenetic sensors and actuators, and specific challenges in moving towards in vivo cardiac optogenetics.
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Affiliation(s)
- Christina M Ambrosi
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8661, USA
| | - Aleksandra Klimas
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8661, USA
| | - Jinzhu Yu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8661, USA
| | - Emilia Entcheva
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-8661, USA.
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