Estimating physiological parameters
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.
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, wherein the video processing module is further configured 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; 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 is further configured to compute the PSNR for each of the plurality of blocks.
3. The PPM device as claimed in claim 1 , wherein the video processing module is further configured 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 is further configured 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. 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;
enhancing the PPG signal for determining a value of the physiological parameter for the subject;
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.
6. The method as claimed in claim 5 , wherein the method further comprises computing the PSNR for each of the plurality of blocks.
7. The method as claimed in claim 5 , 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.
8. The method as claimed in claim 5 , 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.
9. The method as claimed in claim 5 , wherein the physiological parameter comprises at least one of a heart rate, a blood pressure, and an oxygen saturation.
10. 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;
enhancing the PPG signal for determining a value of the physiological parameter for the subject;
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.
11. The non-transitory computer-readable medium as claimed in claim 10 , wherein the method further comprises computing the PSNR for each of the plurality of blocks.
12. The non-transitory computer-readable medium as claimed in claim 10 , 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.
13. The non-transitory computer-readable medium as claimed in claim 10 , 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.
14. The non-transitory computer-readable medium as claimed in claim 10 , wherein the physiological parameter comprises at least one of a heart rate, a blood pressure, and an oxygen saturation.