|
1
|
Arai S, Lloyd K, Takahashi T, Mammoto K, Miyazawa T, Tamura K, Kaneko T, Ishida K, Moriyama Y, Mitsui T. Dynamic Properties of Heart Fragments from Different Regions and Their Synchronization. Bioengineering (Basel) 2020; 7:E81. [PMID: 32751255 PMCID: PMC7552607 DOI: 10.3390/bioengineering7030081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/17/2020] [Accepted: 07/23/2020] [Indexed: 12/29/2022] Open
Abstract
The dynamic properties of the heart differ based on the regions that effectively circulate blood throughout the body with each heartbeat. These properties, including the inter-beat interval (IBI) of autonomous beat activity, are retained even in in vitro tissue fragments. However, details of beat dynamics have not been well analyzed, particularly at the sub-mm scale, although such dynamics of size are important for regenerative medicine and computational studies of the heart. We analyzed the beat dynamics in sub-mm tissue fragments from atria and ventricles of hearts obtained from chick embryos over a period of 40 h. The IBI and contraction speed differed by region and atrial fragments retained their values for a longer time. The major finding of this study is synchronization of these fragment pairs physically attached to each other. The probability of achieving this and the time required differ for regional pairs: atrium-atrium, ventricle-ventricle, or atrium-ventricle. Furthermore, the time required to achieve 1:1 synchronization does not depend on the proximity of initial IBI of paired fragments. Various interesting phenomena, such as 1:n synchronization and a reentrant-like beat sequence, are revealed during synchronization. Finally, our observation of fragment dynamics indicates that mechanical motion itself contributes to the synchronization of atria.
Collapse
Affiliation(s)
- Shin Arai
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa 252-5258, Japan; (S.A.); (K.L.); (T.T.); (K.M.); (T.M.); (K.T.); (K.I.); (Y.M.)
| | - Kento Lloyd
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa 252-5258, Japan; (S.A.); (K.L.); (T.T.); (K.M.); (T.M.); (K.T.); (K.I.); (Y.M.)
| | - Tomonori Takahashi
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa 252-5258, Japan; (S.A.); (K.L.); (T.T.); (K.M.); (T.M.); (K.T.); (K.I.); (Y.M.)
| | - Kazuki Mammoto
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa 252-5258, Japan; (S.A.); (K.L.); (T.T.); (K.M.); (T.M.); (K.T.); (K.I.); (Y.M.)
| | - Takashi Miyazawa
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa 252-5258, Japan; (S.A.); (K.L.); (T.T.); (K.M.); (T.M.); (K.T.); (K.I.); (Y.M.)
| | - Kei Tamura
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa 252-5258, Japan; (S.A.); (K.L.); (T.T.); (K.M.); (T.M.); (K.T.); (K.I.); (Y.M.)
| | - Tomoyuki Kaneko
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo 184-8584, Japan;
| | - Kentaro Ishida
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa 252-5258, Japan; (S.A.); (K.L.); (T.T.); (K.M.); (T.M.); (K.T.); (K.I.); (Y.M.)
| | - Yuuta Moriyama
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa 252-5258, Japan; (S.A.); (K.L.); (T.T.); (K.M.); (T.M.); (K.T.); (K.I.); (Y.M.)
| | - Toshiyuki Mitsui
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa 252-5258, Japan; (S.A.); (K.L.); (T.T.); (K.M.); (T.M.); (K.T.); (K.I.); (Y.M.)
| |
Collapse
|
|
2
|
Liu H, Yan J, Zhou Y, Li H, Li C. A novel dynamic cardiac simulator utilizing pneumatic artificial muscle. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:715-718. [PMID: 24109787 DOI: 10.1109/embc.2013.6609600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
With the development of methods and skills of minimally invasive surgeries, equipments for doctors' training and practicing are in high demands. Especially for the cardiovascular surgeries, operators are requested to be familiar with the surgical environment of a beating heart. In this paper, we present a new dynamic cardiac simulator utilizing pneumatic artificial muscle to realize heartbeat. It's an artificial left ventricular of which the inner chamber is made of thermoplastic elastomers (TPE) with an anatomical structure of the real human heart. It is covered by another layer of material forming the artificial muscle which actuates the systole and diastole uniformly and omnidirectionally as the cardiac muscle does. Preliminary experiments were conducted to evaluate the performance of the simulator. The results indicated that the pressure at the terminal of the aorta could be controlled within the range of normal human systolic pressure, which quantitatively validated the new actuating mode of the heart-beating is effective.
Collapse
|