# US 11,298,187 B2 · Method and system for image processing to determine patient-specific blood flow characteristics

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- Number: US 11,298,187 B2
- Document ID: US11298187B2
- Status: Granted
- Kind: B2
- Application number: 16/118,051
- Filed: 2018-08-30
- Published: 2018-12-27
- Granted: 2022-04-12
- Earliest claimed: 2010-08-12
- Assignees: HeartFlow, Inc.
- Applicants: HeartFlow, Inc.
- Inventors: Charles A. Taylor
- Web page: https://patentgrep.com/patent/US11298187B2

## CPC

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- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
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## Abstract

Embodiments include a system for determining cardiovascular information for a patient. The system may include at least one computer system configured to receive patient-specific data regarding a geometry of the patient's heart, and create a three-dimensional model representing at least a portion of the patient's heart based on the patient-specific data. The at least one computer system may be further configured to create a physics-based model relating to a blood flow characteristic of the patient's heart and determine a fractional flow reserve within the patient's heart based on the three-dimensional model and the physics-based model.

## Claims

### Claim 1

A processing apparatus for processing cardiac data of a living being, the apparatus comprising:
a measurement device configured to measure pressure values in arteries of the living being; and
at least one processor configured to:
provide computed first fractional flow reserve values indicative of fractional flow reserve of different arteries of the living being, wherein said computed first fractional flow reserve values were calculated from non-invasive imaging data of coronary arteries of the living being;
determine second fractional flow reserve values based on measured pressure values obtained via the measurement device in the arteries of the living being at positions corresponding to the first fractional flow reserve values;
adjust the provided computed first fractional flow reserve values based on the determined second fractional flow reserve values;
determine a further computed first fractional flow reserve value at a position for which a second fractional flow value is not or not yet available based on at least one of the adjusted first fractional reserve values;
provide an arterial tree model from the non-invasive imaging data of the coronary arteries of the living being and in-artery imaging; and
display the coronary arteries of the living being and display the further computed first fractional flow reserve value at or near a location in the arterial tree model corresponding to the position at which the further computed first fractional flow reserve value was determined.

### Claim 2 (depends on 1)

The processing apparatus according to claim 1, wherein the at least one processor is configured to adjust at least one computed first fractional flow reserve value for a position in the coronary arteries of the living being by replacing a value of one or more boundary conditions based on a determined second fractional flow reserve value that is measured at a same position in the coronary arteries of the living being.

### Claim 3 (depends on 1)

The processing apparatus according to claim 1, wherein the at least one processor is configured to adjust a respective computed first fractional flow reserve in response to a corresponding determined second fractional flow reserve value being provided.

### Claim 4 (depends on 1)

The processing apparatus according to claim 1, wherein the at least one processor is configured to adjust a computed first fractional flow reserve value only upon determining that a difference between the computed first fractional flow reserve value and the corresponding determined second fractional flow reserve value is above a predetermined threshold value.

### Claim 5 (depends on 1)

The processing apparatus according to claim 1, further comprising:
a display unit configured to display at least one computed first fractional flow reserve value and a corresponding determined second fractional flow reserve value for a corresponding position in the coronary arteries.

### Claim 6 (depends on 5)

The processing apparatus according to claim 5, further comprising:
an imaging device for non-invasive imaging a cardiac region of a living being; the imaging device including:
a processing unit for determining fractional flow reserve values; and
the measurement device.

### Claim 7 (depends on 6)

The processing apparatus according to claim 6, wherein the imaging device further includes an image processing unit for reconstructing three dimensional image data from detection data detected by the imaging device.

### Claim 8 (depends on 5)

The processing apparatus according to claim 5, wherein the display unit is further configured to display adjusted fractional flow reserve values in response to adjustment of a computed first fractional flow reserve value.

### Claim 9 (depends on 1)

The processing apparatus of claim 1, wherein the further first computed fractional flow reserve value is determined via interpolation based on at least one of the adjusted computed first factional flow reserve values.

### Claim 10 (depends on 1)

The processing apparatus of claim 1, wherein adjusting the computed first fractional flow reserve values based on the determined second fractional flow reserve values includes:
adjusting one or more values of one or more boundary conditions specific to the coronary arteries of the living being based on a comparison between a computed first fractional flow reserve value at a first positon and a determined second fractional flow reserve value at the first position, the one or more boundary conditions representative of at least one blood flow characteristic at an inflow boundary, an outflow boundary, or a vessel wall boundary of the coronary arteries of the living being; and
causing the computed first fractional flow reserve values to be recomputed based on the adjusted one or more boundary conditions.

### Claim 11 (depends on 10)

The processing apparatus of claim 10, wherein the adjusting of the one or more boundary conditions and the causing of the computed first fractional flow reserve values to be recomputed is performed iteratively until a recomputed first fractional flow reserve value at the first position is within a predetermined threshold of the determined second fractional flow reserve value.

### Claim 12

A method for assessment of stenosis in an arterial tree of a living being, comprising the steps of:
receiving computed first fractional flow reserve values of the arterial tree of the living being calculated from data obtained from non-invasive imaging of the arterial tree;
obtaining in-artery measured pressure values in arteries of the living being via a measurement device;
determining second fractional flow reserve values of the arterial tree, based on the obtained in-artery measured pressure values, at positions corresponding to the computed first fractional flow reserve values;
adjusting the first fractional flow reserve values based on the determined second fractional flow reserve values;
determining a further first computed fractional flow reserve value at a position for which a determined second fractional flow reserve value is not or not yet available based on at least one of the adjusted computed first fractional reserve values;
providing an arterial tree model from the non-invasive imaging data of the arterial tree of the living being; and
displaying the computed first further fractional flow reserve value at or near a location in the arterial tree where the computed first further fractional flow reserve value was determined.

### Claim 13 (depends on 12)

The method of claim 12, wherein the further first computed fractional flow reserve value is determined via interpolation based on at least one of the adjusted first factional flow reserve values.

### Claim 14 (depends on 12)

The method of claim 12, wherein adjusting the computed first fractional flow reserve values based on the determined second fractional flow reserve values includes:
adjusting one or more values of one or more boundary conditions specific to the arterial tree of the living being based on a comparison between a computed first fractional flow reserve value at a first positon and a determined second fractional flow reserve value at the first position, the one or more boundary conditions representative of at least one blood flow characteristic at an inflow boundary, an outflow boundary, or a vessel wall boundary of the arterial tree of the living being; and
causing the computed first fractional flow reserve values to be recomputed based on the adjusted one or more boundary conditions.

### Claim 15 (depends on 14)

The method of claim 14, wherein the adjusting of the one or more boundary conditions and the causing of the computed first fractional flow reserve values to be recomputed is performed iteratively until a recomputed first fractional flow reserve value at the first position is within a predetermined threshold of the determined second fractional flow reserve value.

### Claim 16

A non-transitory computer readable medium having thereon instructions for assessment of stenosis in an arterial tree of a living being, wherein the instructions, when executed on a computer, perform a method that comprises:
receiving computed first fractional flow reserve values of the arterial tree of the living being calculated from data obtained from non-invasive imaging of the arterial tree;
receiving measured pressure values obtained via a measurement device from within arteries of the living being;
determining second fractional flow reserve values of the arterial tree, based on the obtained measured pressure values, at positions corresponding to the computed first fractional flow reserve values;
adjusting the computed first fractional flow reserve values based on the determined second fractional flow reserve values;
determining a further first computed fractional flow reserve value at a position for which a determined second fractional flow reserve value is not or not yet available based on at least one of the adjusted computed first fractional reserve values;
providing an arterial tree model from the non-invasive imaging data of the arterial tree of the living being; and
displaying the computed first further fractional flow reserve value at or near a location in the arterial tree where the computed first further fractional flow reserve value was determined.

### Claim 17 (depends on 16)

The non-transitory computer-readable medium of claim 16, wherein the further first computed fractional flow reserve value is determined via interpolation based on at least one of the adjusted first factional flow reserve values.

### Claim 18 (depends on 16)

The non-transitory computer-readable medium of claim 16, wherein adjusting the computed first fractional flow reserve values based on the determined second fractional flow reserve values includes:
adjusting one or more values of one or more boundary conditions specific to the arterial tree of the living being based on a comparison between a computed first fractional flow reserve value at a first positon and a determined second fractional flow reserve value at the first position, the one or more boundary conditions representative of at least one blood flow characteristic at an inflow boundary, an outflow boundary, or a vessel wall boundary of the arterial tree of the living being; and
causing the computed first fractional flow reserve values to be recomputed based on the adjusted one or more boundary conditions.

### Claim 19 (depends on 18)

The computer-readable medium of claim 18, wherein the adjusting of the one or more boundary conditions and the causing of the computed first fractional flow reserve values to be recomputed is performed iteratively until a recomputed first fractional flow reserve value at the first position is within a predetermined threshold of the determined second fractional flow reserve value.