Patent Application

App. No. 13/967,317

Abstract

Claims (54)

1 . A method comprising:

receiving from an image capture device color channel signals including data representing one or more images;

forming a linear combination of the color channel signals as a combined color channel signal;

transforming continuously at a processor the combined color channel signal to establish local maxima associated with multiple scale parameters;

identifying portions of time associated with the local maxima;

deriving a physiological characteristic based on the portions of time; and

generating a data signal representing the physiological characteristic.

2 . The method of claim 1 , further comprising:

causing presentation at a display of the data representing the physiological characteristic.

3 . The method of claim 1 , wherein deriving a physiological signal comprises:

determining heart beats per unit time.

4 . The method of claim 3 , wherein deriving the physiological characteristic comprises:

determining the heart beats per unit time in real-time based on the combined color channel signal as a substantially continuous time signal.

5 . The method of claim 3 , further comprising:

causing performance of an action based on a value of the heart beats per unit time.

6 . The method of claim 1 , wherein receiving from the image capture device the color channel signals further comprises:

receiving light reflect from a surface of tissue,

wherein the portions of time associated with the local maxima indicate an enhanced blood volume state adjacent to the surface of the tissue.

7 . The method of claim 1 , wherein transforming continuously comprises:

performing a continuous wavelet transformation (“CWT”) of the combined color channel signal.

8 . The method of claim 7 , further comprising:

identifying a portions of time at which a local maximum exists at substantially adjacent values of scale parameters; and

determining the local maximum over the substantially adjacent values of scale parameters constitute a ridge.

9 . The method of claim 7 , wherein performing the continuous wavelet transformation comprises:

applying the continuous wavelet transform over the multiple scale parameters;

identifying a local maximum over values of a contiguous subset of the multiple scale parameters at a portion of time; and

determining a ridge,

wherein the ridge indicates presence of a flush state for a portion of tissue.

10 . The method of claim 9 , further comprising:

identifying multiple ridges over multiple portions of time;

determine timing between multiple flush states over a subset of the multiple portions of time; and

estimating a heart rate based on the timing.

11 . The method of claim 7 , wherein performing the continuous wavelet transformation comprises:

applying a Ricker wavelet to the combined color channel signal.

12 . The method of claim 1 , wherein transforming continuously comprises:

identifying a subset of scale parameters; and

convolving at the processor the combined color channel signal with a continuous wavelet transformation at each value of a scale parameter from the subset of scale parameters.

13 . The method of claim 1 , wherein receiving the color channel signals further comprises:

receiving a signal including a red color channel, a green color channel, and a blue color channel as the color channel signals.

14 . The method of claim 2 , wherein forming the linear combination further comprises:

forming the combined color channel based substantially on the green color channel.

15 . An apparatus comprising:

a processor configured to execute instructions; and

a memory including modules of executable instructions, the modules comprising:

executable instructions to implement a continuous wavelet transformer module configured to transform continuously a combined color channel signal to establish local maxima associated with multiple scale parameters;

executable instructions to implement a maxima detector module configured to identifying portions of time associated with the local maxima for the combined color channel signal, the local maxima specifying a range of frequencies of light associated with a presence of an amount of blood adjacent a tissue surface from which the light in the combined color channel signal originates; and

executable instructions to implement a multi-scale physiological estimator configured to estimate heart beats per unit time in real-time based on the rate at which the portions of time occur over at least a subset of the multiple scale parameters.

16 . The apparatus of claim 15 , wherein the memory further comprises:

executable instructions to implement a color signal combiner module configured to generate a linear combination of a red color channel, a green color channel, and a blue color channel to form the combined color channel signal.

17 . The apparatus of claim 16 , further comprises:

an image capture configured to generate the red color channel, the green color channel, and the blue color channel based on the light reflected from the tissue surface.

18 . The apparatus of claim 16 , further comprises:

a housing in which the processor and the memory are disposed, the housing configured to couple or attach to an appendage.

19 . The apparatus of claim 18 , wherein the apparatus is a wearable computing device configured to be worn at a wrist.

Assignments (12)