Capture control for in vivo camera

• US 7,940,973 B2
• Filed: 05/10/2010
• Issued: 05/10/2011
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: CapsoVision, Inc.
• Original Assignee: CapsoVision, Inc.
• Inventors: Lee, Chung-Ta, Wilson, Gordon C, Wang, Kang-Huai
• Primary Examiner(s): Perungavoor; Sath V.
• Application Number:
  US12/776,434
• Publication Number:
  US 20100220180A1
• Time in Patent Office: 365 Days
• Field of Search: 382/128
• US Class Current: 382/128
• CPC Class Codes: A61B 1/00016 using wireless means
• CPC Class Codes: A61B 1/0002 provided with data storages
• CPC Class Codes: A61B 1/00032 internally powered
• CPC Class Codes: A61B 1/00036 Means for power saving, e.g. sleeping mode
• CPC Class Codes: A61B 1/041 Capsule endoscopes for imaging
• CPC Class Codes: A61B 1/0684 using light emitting diodes [LED]
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/03 Detecting, measuring or recording fluid pressure within the body other than blood pressure, e.g. cerebral pressure; Measuring pressure in body tissues or organs A61B5/205 takes precedence
• CPC Class Codes: A61B 5/073 Intestinal transmitters
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 5/144 Movement detection for video coding H04N19/503; analysis of motion in general G06T7/20

Abstract

Systems and methods are provided for capture control of video data from a capsule camera system having an on-board storage or wireless transmission. The capsule camera system moves through the GI tract under the action of peristalsis and records images of the intestinal walls. For some periods of time, the capsule camera system may move very slowly and there are little differences in the image data between different frames. These frames can be designated for discard to conserve storage space or conserve power. A capsule control processing unit is incorporated to evaluate motion metric based on image data associated with a current frame and a previous frame. A decision is made based on a profile of the motion metric to select an operation mode from a group comprising Capture Mode and Conservation Mode. The capsule camera system is then operated according to the selected operation mode.

Claims

1. A method for capsule camera control, the method comprising:

(a) providing a light source with a first light source control to illuminate lumen walls;

(b) receiving image data from an image sensor of a capsule camera to derive a first frame;

(c) evaluating a motion metric, associated with the first frame and a previously captured frame, based on motion vectors, SAD, MSE, count of pixels having large differences OR count of zero-valued motion vectors;

(d) selecting an operation mode for next image data from a group comprising Capture Mode and Conservation Mode based on a profile of the motion metric, wherein the Capture Mode is selected if the profile indicates an amount of motion between the first frame and the previously captured frame exceeding a threshold and the Conservation Mode is selected otherwise;

(e) adjusting a luminous energy emitted by the light source to cause the light source to emit less luminous energy if the Conservation Mode is selected than if the Capture Mode is selected;

(f) storing a full-sized and full-resolution frame if the mode is the Capture Mode; and

wherein steps (a) through (f) are performed inside a capsule camera.

2. The method of claim 1, wherein said evaluating motion metric is based on a portion of the first frame and a portion of the previously captured frame.

3. The method of claim 2, wherein the portion of the first frame is caused by configuring the image sensor.

4. The method of claim 2, wherein the portion of the first frame is caused by processing the received image data using a processing module.

5. The method of claim 1, wherein the operating mode is stored in storage selected from a group comprising a first memory in the capsule camera and a second memory outside the capsule camera.

6. The method of claim 1, wherein the Capture Mode comprising:

(g) storing a full resolution frame derived from the next image data in an archival memory selected from a group consisting of memory inside the capsule camera and memory external to the capsule camera.

7. The method of claim 1, wherein the Capture Mode comprising:

(g) receiving the next image data from the image sensor to derive a new current frame;

(h) evaluating second motion metric associated with the new current frame and the previously captured frame;

(i) selecting a new operation mode for the frame following the new current frame based on a profile of the second motion metric, wherein the Capture Mode is selected if the profile indicates the amount of motion between the new current frame and the previously captured frame exceeds a second threshold and the Conservation Mode is selected otherwise; and

(j) storing the frame following the new current frame in full-size and full-resolution frame derived in archival memory if the new operation mode is the Capture Mode.

8. The method of claim 7, wherein the Capture Mode further comprising:

(k) discarding the next image data if the new operation mode is the Conservation Mode.

9. The method of claim 7, wherein the next image data is buffered in a buffer memory in a compressed format.

10. The method of claim 7, wherein the Conservation Mode comprising:

(k1) a processing step selected from a group comprising;

(i) configuring the image sensor to cause the image sensor not to output the next image data;

(ii) receiving the next image data from the image sensor and discarding the next image data; and

(iii) receiving the next image data from the image sensor and storing the next image data in reduced size and/or resolution.

11. The method of claim 10, wherein the Conservation Mode further comprising:

(l) configuring the image sensor to cause reduced image size and/or resolution for the next image data before said receiving the next image data from the image sensor.

12. The method of claim 7, wherein the Conservation Mode further comprising:

(k2) providing the light source with a second light source control to substantially reduce luminous energy.

13. The method of claim 12, wherein the first light source control and the second light source control include multiplicative luminous energy control.

14. The method of claim 1, wherein the profile of the motion metric comprises motion matrices corresponding to a current frame and at least one prior frame.

15. A capsule camera apparatus, comprising:

an image sensor, within the capsule camera, to provide image data;

a processing module, within the capsule camera, to derive a first frame and a second frame from the image data;

a motion evaluation module, within the capsule camera, to measure a motion metric based on the first frame and a previously captured frame, the motion metric being based on motion vectors, SAD, MSE, count of pixels having large differences OR count of zero-valued motion vectors;

an archival memory to store a frame according to an archival control;

a decision module, within the capsule camera, to select an operation mode for the second frame from a group comprising Capture Mode and Conservation Mode based on a profile of the motion metric, wherein the Capture Mode is selected if the profile indicates an amount of motion between the first frame and the previously captured frame exceeding a threshold and the Conservation Mode is selected otherwise;

a light source, within the capsule camera, coupled to receive a light source control to adjust luminous energy emitted by the light source, wherein the light source control is provided by the controller to cause the light source to emit less luminous energy if the Conservation Mode is selected for the second frame than the luminous energy if the Capture Mode is selected; and

a controller, within the capsule camera, to provide the archival control based on the operation mode selected, the archival control including at least storing a full-size and full-resolution frame if the mode is the Capture Mode.

16. The capsule camera apparatus of claim 15, wherein if the Capture Mode is selected for the second frame:

the motion evaluation module is configured to evaluate a second motion metric associated with the second frame and a second previously captured frame; and

the controller is configured to cause the second frame to be stored in full size and full resolution if a profile of the second motion metric indicates an amount of motion between the second frame and the second previously captured frame exceeding a second threshold.

17. The capsule camera apparatus of claim 16, wherein the controller is configured to cause the second frame to be discarded if the profile of the second motion metric indicates the amount of motion between the second frame and the second previously captured frame not exceeding the second threshold.

18. The capsule camera apparatus of claim 15, wherein, if Conservation Mode is selected for the second frame, the controller provides the archival control to either cause the second frame to be stored in the archival memory in reduced size and/or reduced resolution or cause the second frame not to be stored in archival memory.

19. The capsule camera apparatus of claim 15, wherein the motion evaluation module measures the motion metric based on a portion of the first frame and a portion of the previously captured frame.

20. A capsule camera apparatus, comprising:

an image sensor, within the capsule camera, to provide image data, wherein image size and/or resolution can be adjusted according to a sensor control applied to the image sensor;

a motion evaluation module, within the capsule camera, to measure a motion metric based on a first frame associated with the image data and a previously captured frame, the motion metric being based on motion vectors, SAD, MSE, count of pixels having large differences OR count of zero-valued motion vectors;

a decision module, within the capsule camera, to select an operation mode for a second frame associated with the image data from a group comprising Capture Mode and Conservation Mode based on a profile of the motion metric, wherein the Capture Mode is selected if the profile indicates an amount of motion between the first frame and the previously captured frame exceeding a threshold and the Conservation Mode is selected otherwise;

a light source, within the capsule camera, coupled to receive a light source control to adjust luminous energy emitted by the light source, wherein the light source control is provided by the controller to cause the light source to emit less luminous energy if the Conservation Mode is selected for the second frame than the luminous energy if the Capture Mode is selected; and

a controller, within the capsule camera, to provide the archival control based on the operation mode selected, the sensor control to cause the image sensor to output full-size and full-resolution image data to form the second frame if the mode is the Capture Mode.

21. The capsule camera apparatus of claim 20, wherein, if the Conservation Mode is selected for the second frame, the controller provides the sensor control to the image sensor to either cause the image sensor to output the image data in reduced size and/or reduced resolution to form the second frame or to cause the image sensor not to output the image data to form the second frame.

22. The capsule camera apparatus of claim 20, wherein the motion evaluation module measures the motion metric based on a portion of the first frame and a portion of the previously captured frame.