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Cardiovascular magnetic resonance compatible physical model of the left ventricle for multi-modality characterization of wall motion and hemodynamics.

Okafor IU, Santhanakrishnan A, Chaffins BD, Mirabella L, Oshinski JN, Yoganathan AP - J Cardiovasc Magn Reson (2015)

Bottom Line: DPIV and PC-CMR results of the center plane flow within the ventricle matched, both qualitatively and quantitatively, with flow from the atrium into the LV having a velocity of about 1.15 m/s for both modalities.The mean difference between CMR and SP was 5.5 ± 3.7%.The model presented here can thus be used for the purposes of: (a) acquiring CMR data for validation of FSI simulations, (b) determining accuracy of cine-CMR reconstruction methods, and

View Article: PubMed Central - PubMed

Affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA. iokafor3@gatech.edu.

No MeSH data available.


Related in: MedlinePlus

Schematic of the in vitro LV flow circuit. The LV physical model is enclosed within an acrylic box filled with water-glycerin solution. Expansion and contraction of the flexible-walled LV model is accomplished via periodic pressure fluctuations of the enclosing fluid using a programmable piston pump (PPP). Flow probes F1 and F2 are used to measure mitral and aortic flow rates, respectively. Measurement locations of two transducers for measurement of LV (P1) and aortic pressures (P2) are indicated. St. Jude Regent BMHVs were used in the mitral and aortic valve positions. The flow direction through the LV model is indicated using a dashed arrow.
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Fig2: Schematic of the in vitro LV flow circuit. The LV physical model is enclosed within an acrylic box filled with water-glycerin solution. Expansion and contraction of the flexible-walled LV model is accomplished via periodic pressure fluctuations of the enclosing fluid using a programmable piston pump (PPP). Flow probes F1 and F2 are used to measure mitral and aortic flow rates, respectively. Measurement locations of two transducers for measurement of LV (P1) and aortic pressures (P2) are indicated. St. Jude Regent BMHVs were used in the mitral and aortic valve positions. The flow direction through the LV model is indicated using a dashed arrow.

Mentions: The LV model was placed inside an acrylic housing that was filled with a 36 % by volume glycerin solution in water (the same fluid as inside the LV model). This solution was used as a blood analogue fluid that mimics the viscosity of blood at 37 °C and closely matches the refractive index of acrylic. Two 23 mm St. Jude Medical RegentTM bileaflet mechanical heart valves (BMHVs) were placed in the model, one at the mitral annulus and one at aortic annulus to ensure unidirectional fluid flow. Figure 2 illustrates the flow system. A programmable piston pump (PPP; Vivitro Systems Inc., Victoria, Canada) was used to induce the LV wall motion by altering the pressure of the fluid in the space between the interior of acrylic chamber housing the LV model and the exterior of the LV model. The LV wall motion in turn generates pulsatile fluid flow into and out of the ventricle through the valves. Absolute pressures were measured at the atrial, ventricular, and aortic positions using pressure transducers (Utah Medical Products Inc., Midvale, UT). Volumetric flow rates into and out of the ventricle were measured using ultrasonic flow probes (Transonic Systems Inc., Ithaca, NY). However, it should be noted that during the CMR experiments, the flow probes were replaced with rigid pipes of the same length and internal diameter of the probes. The ventricular wall motion was studied under physiologic hemodynamic conditions (120/80 mmHg systemic pressure, 3.5 L/min average cardiac output at a heart rate of 70 beats/min).Fig. 2


Cardiovascular magnetic resonance compatible physical model of the left ventricle for multi-modality characterization of wall motion and hemodynamics.

Okafor IU, Santhanakrishnan A, Chaffins BD, Mirabella L, Oshinski JN, Yoganathan AP - J Cardiovasc Magn Reson (2015)

Schematic of the in vitro LV flow circuit. The LV physical model is enclosed within an acrylic box filled with water-glycerin solution. Expansion and contraction of the flexible-walled LV model is accomplished via periodic pressure fluctuations of the enclosing fluid using a programmable piston pump (PPP). Flow probes F1 and F2 are used to measure mitral and aortic flow rates, respectively. Measurement locations of two transducers for measurement of LV (P1) and aortic pressures (P2) are indicated. St. Jude Regent BMHVs were used in the mitral and aortic valve positions. The flow direction through the LV model is indicated using a dashed arrow.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4482204&req=5

Fig2: Schematic of the in vitro LV flow circuit. The LV physical model is enclosed within an acrylic box filled with water-glycerin solution. Expansion and contraction of the flexible-walled LV model is accomplished via periodic pressure fluctuations of the enclosing fluid using a programmable piston pump (PPP). Flow probes F1 and F2 are used to measure mitral and aortic flow rates, respectively. Measurement locations of two transducers for measurement of LV (P1) and aortic pressures (P2) are indicated. St. Jude Regent BMHVs were used in the mitral and aortic valve positions. The flow direction through the LV model is indicated using a dashed arrow.
Mentions: The LV model was placed inside an acrylic housing that was filled with a 36 % by volume glycerin solution in water (the same fluid as inside the LV model). This solution was used as a blood analogue fluid that mimics the viscosity of blood at 37 °C and closely matches the refractive index of acrylic. Two 23 mm St. Jude Medical RegentTM bileaflet mechanical heart valves (BMHVs) were placed in the model, one at the mitral annulus and one at aortic annulus to ensure unidirectional fluid flow. Figure 2 illustrates the flow system. A programmable piston pump (PPP; Vivitro Systems Inc., Victoria, Canada) was used to induce the LV wall motion by altering the pressure of the fluid in the space between the interior of acrylic chamber housing the LV model and the exterior of the LV model. The LV wall motion in turn generates pulsatile fluid flow into and out of the ventricle through the valves. Absolute pressures were measured at the atrial, ventricular, and aortic positions using pressure transducers (Utah Medical Products Inc., Midvale, UT). Volumetric flow rates into and out of the ventricle were measured using ultrasonic flow probes (Transonic Systems Inc., Ithaca, NY). However, it should be noted that during the CMR experiments, the flow probes were replaced with rigid pipes of the same length and internal diameter of the probes. The ventricular wall motion was studied under physiologic hemodynamic conditions (120/80 mmHg systemic pressure, 3.5 L/min average cardiac output at a heart rate of 70 beats/min).Fig. 2

Bottom Line: DPIV and PC-CMR results of the center plane flow within the ventricle matched, both qualitatively and quantitatively, with flow from the atrium into the LV having a velocity of about 1.15 m/s for both modalities.The mean difference between CMR and SP was 5.5 ± 3.7%.The model presented here can thus be used for the purposes of: (a) acquiring CMR data for validation of FSI simulations, (b) determining accuracy of cine-CMR reconstruction methods, and

View Article: PubMed Central - PubMed

Affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA. iokafor3@gatech.edu.

No MeSH data available.


Related in: MedlinePlus