Signal Processing for Intravascular Imaging

• US 20170301089A1
• Filed: 06/06/2017
• Published: 10/19/2017
• Est. Priority Date: 10/07/2013
• Status: Active Grant

• Current Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Original Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Inventors: Lam, Duc, Reynolds, J Steve
• Granted Patent: US 10,134,132 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 8/0891 for diagnosis of blood vessels
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/5207 involving processing of raw data to produce diagnostic data, e.g. for generating an image reconstruction G06T11/00
• CPC Class Codes: A61B 8/5269 involving detection or reduction of artifacts for image enhancement algorithms G06T5/00
• CPC Class Codes: G01S 15/8956 using frequencies at or above 20 MHz
• CPC Class Codes: G01S 15/8977 using special techniques for image reconstruction, e.g. FFT, geometrical transformations, spatial deconvolution, time deconvolution
• CPC Class Codes: G01S 7/52034 Data rate converters
• CPC Class Codes: G01S 7/52046 Techniques for image enhancement involving transmitter or receiver image enhancement by image data processing G06T5/00
• CPC Class Codes: G01S 7/52077 with means for elimination of unwanted signals, e.g. noise or interference
• CPC Class Codes: G06T 2207/30101 Blood vessel; Artery; Vein; Vascular
• CPC Class Codes: G06T 7/0012 Biomedical image inspection

Abstract

An intravascular imaging system includes a transducer capable of generating raw data representative of the structure of a patient'"'"'s vasculature. The system includes an imaging engine for receiving the raw data and generating enhanced data for presentation to a user. The imaging engine includes a coherence filter, an envelope detection module having one or more envelope detectors, and a spatial filter for processing data in various stages. Such stages of processing in the imaging engine act to reduce high frequency noise, generate low frequency data, reduce low frequency noise, and display low frequency data with an improved signal-to-noise ratio. The system can include an image generator for generating an image based on enhanced data and a display for displaying the generated image.

Claims

1. A system for producing high definition intravascular images comprising:

an intravascular imaging catheter assembly configured to generate a raw frame of imaging information that includes a raw set of vectors, with each vector of the raw set of vectors comprising a raw set of data points; and

an imaging engine coupled to the intravascular imaging catheter assembly and being configured to receive the raw frame of imaging information from the intravascular imaging catheter assembly and to produce an enhanced frame of imaging information that includes an enhanced set of vectors, the imaging engine comprising;

(a) a coherence filter configured to (i) group vectors of the raw set of vectors into raw vector groups and (ii) generate a first set of vectors based on comparisons of data points of each raw vector group'"'"'s vectors with one another at like radial positions, wherein each vector of the first set of vectors (A) is representative of the vectors of one of the raw vector groups and (B) comprises a first set of data points having the same number of data points as the raw set of data points,

(b) an envelope detection module configured to generate a second set of vectors based on comparisons of data points within each first set of data points with one another, wherein (i) each vector of the second set of vectors comprises a second set of data points with a smaller number of data points that are representative of the data points of the first set of data points and (ii) the second set of vectors comprises the same number of vectors as the first set of vectors,

(c) a spatial filter configured to (i) group vectors of the second set of vectors into processed vector groups and (ii) generate the enhanced set of vectors based on comparisons of data points of each processed vector group'"'"'s vectors with one another at like and near radial positions, wherein each vector of the enhanced set of vectors (A) is representative of the vectors of one of the processed vector groups and (B) comprises an enhanced set of data points having the same number of data points as the second set of data points, and

(d) an image generator configured to generate an image based on the enhanced frame of imaging information.

2. The system of claim 1, wherein the raw vector groups each consist of two vectors.

3. The system of claim 2, wherein the raw set of vectors has 4096 vectors and the first set of vectors has 2048 vectors.

4. The system of claim 2, wherein the raw set of vectors has 2048 vectors and the first set of vectors has 1024 vectors.

5. The system of claim 2, wherein the raw set of vectors has 1024 vectors and the first set of vectors has 512 vectors.

6. The system of claim 1, wherein the comparisons of data points of each raw vector group'"'"'s vectors with one another at like radial positions comprise averages of said data points.

7. The system of claim 6, wherein the averages comprise means.

8. The system of claim 1, wherein the envelope detection module comprises multiple envelope detectors arranged in parallel, with each envelope detector being configured to generate a subset of the second set of vectors.

9. The system of claim 1, wherein the processed vector groups each consist of four vectors.

10. The system of claim 9, wherein the comparisons of data points of each processed vector group'"'"'s vectors with one another at like and near radial positions comprise comparisons of data points of each processed vector group'"'"'s vectors with one another at like and neighboring radial positions.

11. The system of claim 10, wherein each comparison of data points of the processed vector group'"'"'s vectors with one another at like and neighboring radial positions comprises:

identifying a highest value data point at each radial position of the like and neighboring radial positions,

excluding from the comparison each said highest value data point,

determining a median value data point from remaining data points, and

assigning the median value data point to the enhanced set of data points.

12. The system of claim 1, wherein the system is an IVUS system.

13. The system of claim 1, wherein the high definition intravascular image is generated and displayed in real time.

14. A system for producing high definition intravascular images comprising:

an imaging engine coupled to an intravascular imaging catheter assembly and being configured to receive a raw frame of imaging information from the intravascular imaging catheter assembly, the raw frame of imaging information including a raw set of vectors, with each vector of the raw set of vectors comprising a raw set of data points, the imaging engine being further configured to produce an enhanced frame of imaging information that includes an enhanced set of vectors, the imaging engine comprising;

(a) a coherence filter configured to (i) group vectors of the raw set of vectors into raw vector groups and (ii) generate a first set of vectors based on comparisons of data points of each raw vector group'"'"'s vectors with one another at like radial positions, wherein each vector of the first set of vectors (A) is representative of the vectors of one of the raw vector groups and (B) comprises a first set of data points having the same number of data points as the raw set of data points,

(b) an envelope detection module configured to generate a second set of vectors based on comparisons of data points within each first set of data points with one another, wherein (i) each vector of the second set of vectors comprises a second set of data points with a smaller number of data points that are representative of the data points of the first set of data points and (ii) the second set of vectors comprises the same number of vectors as the first set of vectors,

(c) a spatial filter configured to (i) group vectors of the second set of vectors into processed vector groups and (ii) generate the enhanced set of vectors based on comparisons of data points of each processed vector group'"'"'s vectors with one another at like and near radial positions, wherein each vector of the enhanced set of vectors (A) is representative of the vectors of one of the processed vector groups and (B) comprises an enhanced set of data points having the same number of data points as the second set of data points, and

(d) an image generator configured to generate an image based on the enhanced frame of imaging information; and

a display coupled to the imaging engine and configured to display the image generated by the image generator.

15. The system of claim 14, wherein

the raw vector groups each consist of two vectors, and

the raw set of vectors has 4096 vectors and the first set of vectors has 2048 vectors.

16. The system of claim 14, wherein the comparisons of data points of each raw vector group'"'"'s vectors with one another at like radial positions comprise means of said data points.

17. The system of claim 14, wherein the envelope detection module comprises multiple envelope detectors arranged in parallel, with each envelope detector being configured to generate a subset of the second set of vectors.

18. The system of claim 14, wherein the processed vector groups each consist of four vectors.

19. The system of claim 18, wherein each comparison of data points of the processed vector group'"'"'s vectors with one another at like and near radial positions comprises:

identifying a highest value data point at each radial position of the like and neighboring radial positions,

excluding from the comparison each said highest value data point,

determining a median value data point from remaining data points, and

assigning the median value data point to the enhanced set of data points.

20. A system for producing high definition intravascular images comprising:

an imaging engine coupled to an intravascular imaging catheter assembly and being configured to receive a raw frame of imaging information from the intravascular imaging catheter assembly and to produce an enhanced frame of imaging information, the imaging engine comprising a coherence filter, an envelope detection module, a spatial filter, and an image generator; and

a display coupled to the imaging engine and configured to display the image generated by the image generator.