Auckland Bioengineering Institute


Cardiomyometer

cardiomyometer-1

With each beat, the heart’s cells release a brief pulse of calcium, which triggers force development and cell shortening. This process consumes energy and oxygen and produces heat. Researchers need to be able to measure all these processes simultaneously, while subjecting heart muscle to realistic contraction patterns that mimic the pressure-volume loops experienced by the heart with each beat.

We have completed the construction of an innovative testing device that achieves this goal: The Cardiomyometer. With this device, we can, for the first time, follow all of these subcellular events, beat by beat, in living heart tissue under either normal or diseased conditions.

cardiomyometer-2

Heart muscle samples, about the diameter of a human hair and about 2 mm in length, are loaded into the instrument sensor (labelled ‘5’) and kept alive by flowing solution. We have developed and integrated into this device several innovative measurement systems:

  1. Fluorescence imaging system for recording calcium release
  2. Muscle force and length control apparatus
  3. Microscope system and algorithms that determines internal tissue movement, strain and sarcomere length
  4. Optical Coherence Tomography system for measuring 3D shape change, during contraction
  5. Temperature sensors for measuring muscle heat production.

This system is now being used to study:

  • The complex relationships between muscle mechanical parameters (force and length), calcium transient dynamics, calcium sensitivity of the myofilaments, and the resulting length distribution and muscle displacement/strain.
  • The shortening that occurs inside a muscle sample as it performs work against a “realistic” time-changing load. 

 

Researchers and graduate students


Engineering Team

Experimental Team

Collaborators

Funding partners


  • Vice-Chancellors Strategic Development Fund, The University of Auckland
  • Faculty Research Development Fund, The University of Auckland
  • The Marsden Fund, the Royal Society of New Zealand
  • The Heart Foundation of New Zealand

Publications


  1. Cheuk, M., A. HajiRassouliha, J.-C. Han, P.M.F. Nielsen, and A.J. Taberner, Marker-less, Non-invasive Tracking of the Strain Distribution of Actively Contracting Cardiac Muscle Preparations Journal of Physiology (In preparation), 2018.
  2. Schroeder A, Babarenda Gamage TP, Wang V, Loiselle DS, Nielsen PMF, Nickerson DP, Cheuk M, Taberner AJ, Nash MP & Tran K (2018). Computational Modelling of Cardiac Trabecula Mechanics. ANZIAM J; DOI: 10.21914/anziamj.v59i0.12682.
  3. Taberner, A. J., Johnston, C. M., Pham, T., Han, J.-C., Uddin, R., Loiselle, D. S., Nielsen, P. M. F. (2017). A flow-through infusion calorimeter for measuring muscle energetics: design and performance. IEEE Transactions on Instrumentation and measurement, (In press). doi:10.1109/TIM.2018.2800838.
  4. Johnston, C.M., P.M.F. Nielsen, I.W. Hunter, and A. Taberner. Vapor pressure thermometry at room temperature. in 2017 IEEE International Instrumentation and Measurement Technology Conference 2017. Turin, Italy: IEEE.
  5. Cheuk ML (2016). Volumetric Characterisation of Contracting Cardiac Trabeculae: Tracking Tissue Movement. Figshare; DOI: 10.17608/k6.auckland.4168083.v1. Available at: https://doi.org/10.17608/k6.auckland.4168083.v1 [Accessed November 2, 2016].
  6. Loiselle, D. S., Johnston, C. M., Han, J. C., Nielsen, P. M., & Taberner, A. J. (2016). Muscle heat: a window into the thermodynamics of a molecular machine. Am J Physiol Heart Circ Physiol, 310(3), H311-325. doi:10.1152/ajpheart.00569.2015
  7. Cheuk, M.L., C.J. Johnston, J.-C. Han, D.S. Loiselle, P.M.F. Nielsen, and A.J. Taberner. Cardiac Muscle Energetics: Improved Normalisation of Heat using Optical Coherence Tomography. in 38th International Conference of the IEEE Engineering in Medicine and Biology Society. 2016. Florida, USA.
  8. Johnston, C. M., Han, J. C., Ruddy, B. P., Nielsen, P. M., & Taberner, A. J. (2015). A high-resolution thermoelectric module-based calorimeter for measuring the energetics of isolated ventricular trabeculae at body temperature. Am J Physiol Heart Circ Physiol, 309(2), H318-324. doi:10.1152/ajpheart.00194.2015
  9. Johnston, C.M., B.P. Ruddy, P.M.F. Nielsen, and A.J. Taberner. Thermopile power measurement for heat balance calorimetry. in 8th International Conference on Sensing Technology (ICST 2014). 2014. Liverpool, England.
  10. Cheuk, M.L., N. Lippok, A.W. Dixon, B.P. Ruddy, F. Vanholsbeeck, P.M.F. Nielsen, and A.J. Taberner. Optical coherence tomography imaging of cardiac trabeculae. in 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2014 2014.
  11. Anderson, A.J., P.M.F. Nielsen, and A.J. Taberner. An investigation into the viability of image processing for the measurement of sarcomere length in isolated cardiac trabeculae. in Engineering in Medicine and Biology Society (EMBC), 2012 Annual International Conference of the IEEE. 2012.

 

Top