Estimating physiological parameters

Patent metadata

Field	Value
Publication number	US-2016113531-A1
Application number	US-201514665657-A
Country	US
Kind code	A1
Filing date	Mar 23, 2015
Priority date	Oct 27, 2014
Publication date	Apr 28, 2016
Grant date	—

Abstract

A physiological parameter measurement device comprising a processor and a video processing module coupled to the processor to divide each of a plurality of frames of a video into a plurality of blocks, where the video is of a body part of a subject whose physiological parameter is to be determined. The video processing module further is to select a block having highest peak signal to noise ratio (PSNR) from amongst the plurality of blocks. Further, the video processing module is to extract a photoplethysmogram (PPG) signal from the video based on a block identifier associated with the block. The physiological parameter measurement device further comprises a signal enhancement module coupled to the processor, to process the PPG signal to obtain an enhanced PPG signal for determining a value of the physiological parameter for the subject.

First claim

I/we claim:

1 . A physiological parameter measurement (PPM) device, the PPM device comprising:
a processor; a video processing module coupled to the processor to,
divide each of a plurality of frames of a video into a plurality of blocks, wherein the video is of a body part of a subject whose physiological parameter is to be determined;
select a block, from amongst the plurality of blocks, having highest peak signal to noise ratio (PSNR);
extract a photoplethysmogram (PPG) signal from the video based on a block identifier associated with the block; and
a signal enhancement module coupled to the processor to,
enhance the PPG signal for determining a value of the physiological parameter associated with the subject.

2 . The PPM device as claimed in claim 1 , wherein the video processing module further is to compute a PSNR for each of the plurality of blocks.

3 . The PPM device as claimed in claim 1 , wherein the video processing module further is to,
determine the block identifier associated with the block; and identify a region in each frame of the video based on the block identifier; and select the identified region corresponding to each of the frames of the video for extracting the PPG signal.

4 . The PPM device as claimed in claim 1 , wherein the signal enhancement module further is to,
filter the PPG signal to obtain a filtered PPG signal; and apply an interpolation technique on the filtered PPG signal to enhance the PPG signal.

5 . The PPM device as claimed in claim 1 , wherein the video processing module further is to,
adjust an intensity level of a flash of a camera of the PPM device to operate the camera at one or more intensity levels of the flash for capturing a test video of the subject at each of the one or more intensity levels of the flash; for each of the one or more intensity levels of the flash, determine a PSNR for the test video captured at the intensity level of flash; determine, from amongst the test videos captured at the one or more intensity levels of the flash, a test video having highest PSNR; and capture the video of the subject at the intensity level of flash corresponding to the test video having the highest PSNR.

6 . A method comprising:
dividing, by a processor, each of a plurality of frames of a video into a plurality of blocks, wherein the video is of a body part of a subject whose physiological parameter is to be determined; selecting a block, from amongst the plurality of blocks, having highest peak signal to noise ratio (PSNR); extracting a photoplethysmogram (PPG) signal from the video based on a block identifier associated with the block; and enhancing the PPG signal for determining a value of the physiological parameter for the subject.

7 . The method as claimed in claim 6 , wherein the method further comprises computing a PSNR for each of the plurality of blocks.

8 . The method as claimed in claim 6 , wherein the extracting comprises:
ascertaining the block identifier associated with the block; identifying a region in each frame of the video based on the block identifier; and selecting the region corresponding to each of the frames of the video for extracting the PPG signal.

9 . The method as claimed in claim 6 , wherein the enhancing the PPG signal further comprises:
filtering the PPG signal to obtain a filtered PPG signal; and applying an interpolation technique on the filtered PPG signal to enhance the PPG signal.

10 . The method as claimed in claim 6 , wherein the physiological parameter comprises at least one of a heart rate, a blood pressure, and an oxygen saturation.

11 . The method as claimed in claim 6 , wherein the method further comprises:
adjusting an intensity level of a flash of a camera to operate the camera at one or more intensity levels of the flash for capturing a test video of the subject at each of the one or more intensity levels of the flash; for each of the one or more intensity levels of the flash, determining a PSNR for a test video captured at the intensity level of flash; determining, from amongst the test videos captured at the one or more intensity levels of the flash, a test video having highest PSNR; and capturing the video of the subject at the intensity level of flash corresponding to the test video having the highest PSNR.

12 . A non-transitory computer-readable medium having embodied thereon a computer program for executing a method comprising:
dividing, by a processor, each of a plurality of frames of a video into a plurality of blocks, wherein the video is of a body part of a subject whose physiological parameter is to be determined; selecting a block, from amongst the plurality of blocks, having highest peak signal to noise ratio (PSNR); extracting a photoplethysmogram (PPG) signal from the video based on a block identifier associated with the block; and enhancing the PPG signal for determining a value of the physiological parameter for the subject.

13 . The non-transitory computer-readable medium as claimed in claim 12 , wherein the method further comprises computing a PSNR for each of the plurality of blocks.

14 . The non-transitory computer-readable medium as claimed in claim 12 , wherein the extracting comprises:
ascertaining the block identifier associated with the block; identifying a region in each frame of the video based on the block identifier; and selecting the region corresponding to each of the frames of the video for extracting the PPG signal.

15 . The non-transitory computer-readable medium as claimed in claim 12 , wherein the enhancing the PPG signal further comprises:
filtering the PPG signal to obtain a filtered PPG signal; and applying an interpolation technique on the filtered PPG signal to enhance the PPG signal.

16 . The non-transitory computer-readable medium as claimed in claim 12 , wherein the physiological parameter comprises at least one of a heart rate, a blood pressure, and an oxygen saturation.

17 . The non-transitory computer-readable medium as claimed in claim 12 , wherein the method further comprises:
adjusting an intensity level of a flash of a camera to operate the camera at one or more intensity levels of the flash for capturing a test video of the subject at each of the one or more intensity levels of the flash; for each of the one or more intensity levels of the flash, determining a PSNR for a test video captured at the intensity level of flash; determining, from amongst the test videos captured at the one or more intensity levels of the flash, a test video having highest PSNR; and capturing the video of the subject at the intensity level of flash corresponding to the test video having the highest PSNR.

Assignees

• Tata Consultancy Services Ltd

Inventors

• Visvanathan Aishwarya
• Pal Arpan
• Sinha Aniruddha
• Banerjee Rohan
• Dutta Choudhury Anirban
• Mishra Aditi
• Ghose Avik

Classifications

• A61B5/02416 Primary

  using photoplethysmograph signals, e.g. generated by infrared radiation (A61B5/14552 takes precedence) · CPC title

• A61B5/0082

  adapted for particular medical purposes · CPC title

• A61B5/02438

  with portable devices, e.g. worn by the patient · CPC title

• A61B2560/0238

  Means for recording calibration data · CPC title

• A61B5/14551

  for measuring blood gases · CPC title