Framework for personalization of coronary flow computations during rest and hyperemia
Embodiments relate to non-invasively determining coronary circulation parameters during a rest state and a hyperemic state for a patient. The blood flow in the coronary arteries during a hyperemic state provides a functional assessment of the patient's coronary vessel tree. Imaging techniques are used to obtain an anatomical model of the patient's coronary tree. Rest boundary conditions are computed based on non-invasive measurements taken at a rest state, and estimated hyperemic boundary conditions are computed. A feedback control system performs a simulation matching the rest state utilizing a model based on the anatomical model and a plurality of controllers, each controller relating to respective output variables of the coronary tree. The model parameters are adjusted for the output variables to be in agreement with the rest state measurements, and the hyperemic boundary conditions are accordingly adjusted. The hyperemic boundary conditions are used to compute coronary flow and coronary pressure variables.
1. A method of non-invasively determining coronary circulation parameters during a hyperemic state for a patient, the method comprising:
obtaining an image of an anatomical framework of the patient through an image acquisition device;
obtaining an anatomical model of a coronary tree of the patient based on the anatomical image;
determining rest boundary conditions of the patient based on non-invasive measurements taken at a rest state, wherein the rest boundary conditions include a rate-pressure product, a flow through a particular vessel outlet, and terminal resistances;
computing hyperemic boundary conditions of the patient, wherein the hyperemic boundary conditions of the patient are a product of a total coronary resistance index and the rest boundary conditions of the patient;
adjusting the anatomical model to match the rest state by iteratively generating simulated values of flow and pressure until the simulated values match the rest boundary conditions, wherein parameters of the anatomical model are adjusted during each iteration using a plurality of controllers, each controller corresponding to a different output variable of the coronary tree; wherein a first controller of the plurality of controllers is a Proportional Integral (PI) controller that calculates coronary resistance of the coronary tree, and wherein a second controller of the plurality of controllers is a Proportional Integral Derivative (PID) controller that calculates a difference between an initial left ventricle volume and a dead volume;
adjusting the hyperemic boundary conditions based on the adjustments to the anatomical model;
performing a flow computation corresponding to the hyperemic state using the adjusted anatomical model; and
providing a report identifying one or more results of the flow computation that includes a functional assessment of the patient's coronary tree and coronary flow reserve parameters.
2. The method of claim 1 , wherein the anatomical model of the coronary tree of the patient is obtained via at least one of a CT scan, an MRI scan, an angiography scan, an ultrasound scan, and a cardiac perfusion scan.
3. The method of claim 1 , wherein the non-invasive measurements taken at a rest state comprise one or more of heart rate, systolic blood pressure, and diastolic blood pressure.
4. The method of claim 1 , wherein the rest boundary conditions of the patient comprise terminal resistance and capacitance values at vessel outlets during the rest state.
5. The method of claim 4 , wherein the rest boundary conditions of the patient based on the terminal resistance and capacitance values at vessel outlets during the rest state are adjusted using information from a cardiac perfusion exam.
6. The method of claim 1 , wherein the hyperemic boundary conditions of the patient based on the terminal resistance and capacitance values at vessel outlets during the hyperemic state are adjusted using information from a cardiac perfusion exam.
7. A feedback control system for non-invasively determining coronary circulation parameters during a hyperemic state for a patient, the system comprising:
one or more processors configured to calculate (i) rest boundary conditions of the patient based on non-invasive measurements taken at a rest state, wherein the rest boundary conditions include a rate-pressure product, a flow through a particular vessel outlet, and terminal resistances; and (ii) hyperemic boundary conditions of the patient, wherein the hyperemic boundary conditions of the patient are a product of a total coronary resistance index and the rest boundary conditions of the patient;
wherein the one or more processors are further configured to: adjust an anatomical model provided based on an anatomical image, to match the rest state by iteratively generating simulated values of flow and pressure until the simulated values match the rest boundary conditions, wherein parameters of the anatomical model are adjusted during each iteration using a plurality of controllers each controller corresponding to a different output variable of the coronary tree; wherein a first controller of the plurality of controllers is a Proportional Integral (PI) controller that calculates coronary resistance of the coronary tree, and wherein a second controller of the plurality of controllers is a Proportional Integral Derivative (PID) controller that calculates a difference between an initial left ventricle volume and a dead volume;
wherein the one or more processors are further configured to: adjust the hyperemic boundary conditions based on the adjustments to the parameters of the anatomical model; and perform a flow computation corresponding to the hyperemic state using the adjusted anatomical model;
wherein the one or more processors are further configured to: provide a report identifying one or more results of the flow computation that includes a functional assessment of the patient's coronary tree and coronary flow reserve parameters.
8. The system of claim 7 , wherein the anatomical model of the coronary tree of the patient is obtained via at least one of a CT scan, an MM scan, an angiography scan, an ultrasound scan, and a cardiac perfusion scan.
9. The system of claim 7 , wherein the non-invasive measurements taken at a rest state comprise one or more of heart rate, systolic blood pressure, and diastolic blood pressure.
10. The system of claim 7 , wherein the rest boundary conditions of the patient comprise terminal resistance and capacitance values at vessel outlets during the rest state.
11. A non-transitory computer-readable media comprising software instructions for non-invasively determining coronary circulation parameters during a hyperemic state for a patient by:
obtaining an image of an anatomical framework of the patient through an image acquisition device;
obtaining an anatomical model of a coronary tree of the patient based on the anatomical image;
determining rest boundary conditions of the patient based on non-invasive measurements taken at a rest state, wherein the rest boundary conditions include a rate-pressure product, a flow through a particular vessel outlet, and terminal resistances;
computing hyperemic boundary conditions of the patient, wherein the hyperemic boundary conditions of the patient are a product of a total coronary resistance index and the rest boundary conditions of the patient;
adjusting the anatomical model to match the rest state by iteratively generating simulated values of flow and pressure until the simulated values match the rest boundary conditions, wherein parameters of the anatomical model are adjusted during each iteration using a plurality of controllers each controller corresponding to a different output variable of the coronary tree; wherein a first controller of the plurality of controllers is a Proportional Integral (PI) controller that calculates coronary resistance of the coronary tree, and wherein a second controller of the plurality of controllers is a Proportional Integral Derivative (PID) controller that calculates a difference between an initial left ventricle volume and a dead volume;
adjusting the hyperemic boundary conditions based on the adjustments to the anatomical model;
performing a flow computation corresponding to the hyperemic state using the adjusted anatomical model; and
providing a report identifying one or more results of the flow computation that includes a functional assessment of the patient's coronary tree and coronary flow reserve parameters.
12. The non-transitory computer-readable media of claim 11 , wherein the non-invasive measurements taken at a rest state comprise one or more of heart rate, systolic blood pressure, and diastolic blood pressure.
13. The non-transitory computer-readable media of claim 11 , wherein the rest boundary conditions of the patient comprise terminal resistance and capacitance values at vessel outlets during the rest state.