METHODS AND APPARATUS FOR HPRF DOPPLER ULTRASONIC IMAGING

• US 20110178406A1
• Filed: 01/14/2011
• Published: 07/21/2011
• Est. Priority Date: 01/21/2010
• Status: Active Grant

• Current Assignee: Shenzhen Mindray Bio-Medical Electronics Co., Ltd. (Excelsior Union Ltd.)
• Original Assignee: Shenzhen Mindray Bio-Medical Electronics Co., Ltd. (Excelsior Union Ltd.)
• Inventors: Lei, Li, Shuangshuang, Li
• Granted Patent: US 8,647,277 B2
• Time in Patent Office: Days
• US Class Current: 600/453
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: G01S 15/8986 with measures taken for suppressing velocity ambiguities, i.e. anti-aliasing
• CPC Class Codes: G01S 7/52019 Details of transmitters
• CPC Class Codes: G01S 7/5205 Means for monitoring or calibrating

Abstract

A method for High Pulse Repeat Frequency (HPRF) Doppler ultrasonic imaging comprises: collecting parameters including a selected PRF level, real sample volume depth and sampling gate size; setting a selectable PRF range according to a standard PRF value corresponding to the selected PRF level; evaluating each PRF successively selected from the selectable PRF range with a preset step; and taking the PRF with best evaluation as the best PRF of the selected PRF level to be used in ultrasonic pulses transmission.

Claims

1. A method for High Pulse Repeat Frequency (HPRF) Doppler ultrasonic imaging, comprising:

collecting parameters including a selected PRF level, real sample volume depth and sampling gate size;

setting a selectable PRF range according to a standard PRF value corresponding to the selected PRF level;

evaluating each PRF successively selected from the selectable PRF range with a preset step; and

taking the PRF with best evaluation as the best PRF of the selected PRF level to be used in transmission of ultrasonic pulses.

2. The method of claim 1, further comprising:

judging a sampling gate size whether a maximum value is smaller than a minimum value, wherein the maximum value is the maximum between a lower limit of a selectable PRF range restricted by a current sampling gate and the lower limit of the set selectable PRF range, the minimum value is the minimum between an upper limit of the selectable PRF range restricted by the current sampling gate and the upper limit of the set selectable PRF range;

if the maximum value is smaller than the minimum value, proceeding to the evaluating step, otherwise, reducing the sampling gate size, and reprocessing the judging step of sampling gate size.

3. The method of claim 1, further comprising:

calculating a virtual sample volume depth based on the best PRF and current real sample volume depth, and judging whether the calculated virtual sample volume depth is smaller than a preset threshold;

if the calculated virtual sample volume depth is smaller than the preset threshold, proceeding to a next PRF level to search for the corresponding best PRF with the setting step and the evaluating step, otherwise, the best PRF is utilized in ultrasonic pulses transmission.

4. The method of claim 1, wherein, before the evaluating step, the method further comprises:

calculating a virtual sample volume depth based on the selected PRF and the current real sample volume depth, and judging whether the calculated virtual sample volume depth is smaller than a preset threshold;

if the calculated virtual sample volume depth is smaller than the preset threshold, proceeding to next PRF level to reprocess the reinforcing judgment step, otherwise, proceeding to the evaluating step.

5. The method of claim 1, wherein the setting step comprises:

setting the selectable PRF range by multiplying the standard PRF value corresponding to the selected PRF level by a preset lower limit parameter and an upper limit parameter respectively, wherein the lower parameter is less than or equal to 1, and the upper parameter is greater than or equal to 1.

6. The method of claim 1, wherein the setting step comprises:

setting the selectable PRF range by subtracting and adding the standard PRF value corresponding to the selected PRF level by preset adjustment parameters respectively, wherein the adjustment parameter is greater than or equal to zero.

7. The method of claim 1, wherein the evaluating step comprises:

if a dead-time number of the PRF evaluated currently is larger than or equal to a preset upper limit of dead-time number, the score of the PRF is set with a worst score, otherwise, the score of the PRF is a function of one or at least any two of the following three scoring items;

a scoring distance to a previous adjacent dead time, a scoring distance to a next adjacent dead time, and a scoring similarity with the standard PRF value corresponding to a current PRF level.

8. The method of claim 7, wherein the scoring distance to the previous adjacent dead time is a function of the time distance from a beginning time to the previous dead time, wherein the beginning time is the one at which the signal at the beginning position of sampling gate returns to the probe;

and wherein the greater the time distance, the better the score.

9. The method of claim 7, wherein the scoring distance to the next adjacent dead time is a function of the time distance from an end time to the next dead time, wherein the end time is the one at which the signal at the end position of sampling gate returns to the probe;

and wherein the greater the distance, the better the score.

10. The method of claim 7, wherein a scoring similarity with the standard PRF value corresponding to the current PRF level is a function of the difference between the PRF evaluated currently and the standard PRF value corresponding to the current PRF level;

and wherein the smaller the difference, the better the score.

11. An apparatus for HPRF Doppler ultrasonic imaging, comprising:

a collecting unit configured for collecting parameters, the parameters including a selected PRF level, real sample volume depth, and sampling gate size;

a setting unit configured for setting an selectable PRF range according to a standard PRF value corresponding to the selected PRF level; and

an evaluating unit configured for evaluating each PRF successively selected from the selectable PRF range with a preset step;

wherein the apparatus is to take the PRF with the best evaluation as the best PRF of the selected PRF level, which is to be utilized in ultrasonic pulses transmission.

12. The apparatus of claim 11, further comprising:

a judging unit of sampling gate size configured for judging whether a maximum value is smaller than a minimum value, wherein the maximum value is the maximum between a lower limit of a selectable PRF range restricted by the current sampling gate and the lower limit of the set selectable PRF range, the minimum value is the minimum between a upper limit of the selectable PRF range restricted by the current sampling gate and the upper limit of the set selectable PRF range;

if the maximum value is smaller than the minimum value, proceeding to the evaluating unit, otherwise, reducing the sampling gate size and reprocessing the judging unit of sampling gate size.

13. The apparatus of claim 11, further comprising:

a reinforcing judgment unit configured for calculating virtual sample volume depth based on the best PRF and current real sample volume depth, and for judging whether the calculated virtual sample volume depth is smaller than a preset threshold;

if the calculated virtual sample volume depth is smaller than the preset threshold, proceeding to next PRF level to search the corresponding best PRF with the setting unit and the evaluating unit, otherwise, the best PRF is utilized in ultrasonic pulses transmission.

14. The apparatus of claim 11, further comprising:

a reinforcing judgment unit configured for calculating virtual sample volume depth based on the selected PRF and current real sample volume depth, judging whether the calculated virtual sample volume depth is smaller than a preset threshold;

if the calculated virtual sample volume depth is smaller than the preset threshold, proceeding to next PRF level to reprocess the reinforcing judgment unit, otherwise, proceeding to the evaluating unit.

15. The apparatus of claim 11, wherein the setting unit is configured to set the selectable PRF range by multiplying the standard PRF value corresponding to the selected PRF level by a preset lower parameter and upper parameter, wherein the lower parameter is smaller than or equal to 1, and the upper parameter is larger than or equal to 1.

16. The apparatus of claim 11, wherein the setting unit is configured to set the selectable PRF range by subtracting the standard PRF value corresponding to the selected PRF level with a preset adjustment parameter, wherein the adjustment parameter is larger than or equal to zero.

17. The apparatus of claim 11, wherein, if a dead-time number of the PRF evaluated currently is larger than or equal to a preset upper limit of dead-time number, the score of the PRF is set with a worst score, otherwise, the score of the PRF is a function of one or at least any two of the following three scoring items:

the scoring distance to the previous adjacent dead time, the scoring distance to the next adjacent dead time, and the scoring similarity with the standard PRF value corresponding to current PRF level.

18. A Doppler ultrasonic imaging system comprising the apparatus of claim 11.