SENSOR DATA TRANSMISSIONS

• US 20160278648A1
• Filed: 03/26/2015
• Published: 09/29/2016
• Est. Priority Date: 03/26/2015
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Wei, John C., Yeung, Fai Angus, Vogel, Brian K.
• Granted Patent: US 10,292,607 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0431 Portable apparatus, e.g. comprising a handle or case
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/6817 Ear canal
• CPC Class Codes: A61B 5/6898 Portable consumer electronic devices, e.g. music players, telephones, tablet computers
• CPC Class Codes: A61B 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04M 1/724097 Worn on the head
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion telephones including GPS signal receivers H04M2250/10
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Technology for a wearable heart rate monitoring device is disclosed. The wearable heart rate monitoring device can include a heart rate sensor operable to collect sensor data, a modulator operable to generate a modulated signal that includes the sensor data, a housing configured to engage a body feature or surface in a manner that allows for heart rate detection, and a communication module configured to transmit the sensor data in the modulated signal to a mobile computing device via a wired connection that is power limited. The mobile computing device is typically configured to demodulate the modulated signal in order to extract the sensor data.

Claims

1. A wearable heart rate monitoring device comprising:

a sensor operable to collect sensor data;

a modulator operable to generate a modulated signal that includes the sensor data;

a housing configured to engage a body feature or surface of a user in a manner that allows for heart rate detection; and

a communication module configured to transmit the sensor data in the modulated signal to a mobile computing device using a wired connection that is power-limited.

2. The wearable heart rate monitoring device of claim 1, wherein the modulator generates the modulated signal using binary frequency-shift keying (BPSK).

3. The wearable heart rate monitoring device of claim 1, wherein the power-limited wired connection includes a headphone line that connects the wearable heart rate monitoring device to the mobile computing device.

4. The wearable heart rate monitoring device of claim 1, wherein the power-limited wired connection includes a microphone line that connects the wearable heart rate monitoring device to the mobile computing device.

5. The wearable heart rate monitoring device of claim 1, wherein the wearable heart rate monitoring device is an in-ear heart rate monitoring headphone.

6. The wearable heart rate monitoring device of claim 1, wherein the sensor data includes noise that exceeds a defined threshold, wherein the noise is caused by electrical coupling in the power-limited wired connection through which the sensor data is communicated to the mobile computing device.

7. The wearable heart rate monitoring device of claim 1, wherein the power-limited wired connection is configured to operate at a power below about 1 mW.

8. The wearable heart rate monitor device of claim 1, wherein the mobile computing device is configured to demodulate the modulated signal in order to extract the sensor data and output the sensor data to a user.

9. The wearable heart rate monitoring device of claim 8, wherein the mobile computing device is further configured to:

receive the sensor data from the wearable heart rate monitoring device via the wired connection, wherein the sensor data includes a series of data samples that are each modulated using one of two frequency tones;

determine a first signal and a second signal associated with each data sample;

determine a sampling rate at which to select data samples from the series of data samples;

select data samples from the series in accordance with the sampling rate, wherein each data sample is selected at a sampling time instance; and

determine a discrete data value for each data sample selected from the series of data samples, wherein the discrete data value is determined based on a comparison of a difference between the first signal and the second signal associated with the data sample with respect to a defined threshold, wherein discrete data values represent demodulated digital sensor data.

10. The wearable heart rate monitoring device of claim 9, wherein:

the discrete data value that corresponds to a selected data sample is “

0”

when the difference (d) between the first signal (r1) and the second signal (r2) is less than the defined threshold;

or

the discrete data value that corresponds to the selected data sample is “

1”

when the difference (d) between the first signal (r1) and the second signal (r2) is greater than the defined threshold,

wherein the defined threshold is represented as;

11. The wearable heart rate monitoring device of claim 9, wherein a single data sample is selected from the series of data samples approximately every 7 data samples or approximately every 12 milliseconds (ms) in accordance with the sampling rate, wherein the approximately 7 data samples or 12 ms is adjusted based on sampling drift.

12. The wearable heart rate monitoring device of claim 9, wherein:

the first signal of the data sample has a frequency greater than zero when the second signal of the data sample has a frequency that is substantially zero;

or

the first signal of the data sample has a frequency that is substantially zero when the second signal of the data sample has a frequency greater than zero.

13. The wearable heart rate monitoring device of claim 9, wherein the two frequency tones used to modulate the data samples in the sensor data include a first frequency tone of approximately 12 kilohertz (kHz) and a second frequency tone of approximately 18 kHz.

14. The wearable heart rate monitoring device of claim 9, wherein the first signal (r1) of the data sample is represented by r₁=√

{square root over (cos(2π

f_ct)²+sin(2π

f_ct)²)} wherein fc is a signal frequency and t is a period of time.

15. The wearable heart rate monitoring device of claim 9, wherein the second signal (r2) of the data sample is represented by r₂=√

{square root over (cos(2π

(f_c+Δ

F)t)²+sin(2π

(f_c+Δ

F)t)²)} wherein fc is a signal frequency, Δ

F is a frequency offset, and t is a period of time.

16. A heart rate monitoring system, comprising:

a wearable heart rate monitoring device as recited in claim 1; and

a mobile computing device in communication with the heart rate monitoring device via a power-limited wired connection, the mobile computing device comprising;

a processor;

a memory device including a data store to store a plurality of data and instructions that, when executed by the processor, cause the processor to execute;

a sensor data receiving module configured to receive sensor data from the heart rate monitoring device via the power-limited wired connection, the sensor data including a series of data samples that are each modulated using one of two frequency tones;

a signal determination module configured to determine a first signal and a second signal associated with each data sample;

a sample rate determination module configured to determine a sampling rate at which to select data samples from the series of data samples;

a data sample selection module configured to select data samples from the series in accordance with the sampling rate, wherein each data sample is selected at a sampling time instance; and

a data value determination module configured to determine a discrete data value for each data sample selected from the series of data samples, wherein discrete data values represent demodulated digital sensor data.

17. The system of claim 16, wherein the sample rate determination module is further configured to:

set the sampling rate to an initial value;

collect data samples based on the sampling rate;

determine that the data samples do not pass at least one of a cyclic redundancy code (CRC) test, a header bit test or a tail bit test; and

increment or decrement the initial value by a defined offset value until the data samples pass the CRC test, the header bit test or the tail bit test, wherein adjustment of the initial value mitigates sampling drift when selecting the data samples from the series of data samples.

18. The system of claim 16, further comprising a filtering module configured to remove frequency components from the series of data samples in the sensor data other than the two frequency tones.

19. The system of claim 16, wherein the signal determination module is further configured to determine the first signal and the second signal via square law processing, wherein the first signal and the second signal are envelope signals.

20. A method of obtaining heart rate data from a subject comprising:

under control of one or more computer systems configured with executable instructions;

collecting sensor data from the subject with a heart rate sensor;

modulating the sensor data with a data modulator to produce a signal that includes the sensor data;

communicating the sensor data to a mobile computing device having one or more processors via a power-limited wired connection; and

demodulating the sensor data from the signal with a data demodulator in the mobile computing device.

21. The method of claim 20, wherein the heart rate sensor is a wearable heart rate sensor device comprising:

a sensor operable to collect sensor data;

a modulator operable to generate a modulated signal that includes the sensor data;

a housing configured to engage a body feature or surface of a user in a manner that allows for heart rate detection; and

a communication module configured to transmit the sensor data in the modulated signal to the mobile computing device using the power-limited wired connection.

22. The method of claim 20, wherein demodulating further comprises:

identifying sensor data that includes a series of data samples at corresponding time instances using the one or more processors of the mobile computing device;

determining a first signal and a second signal associated with each data sample, using the one or more processors of the mobile computing device;

determining a sampling rate at which to select data samples from the series of data samples, using the one or more processors of the mobile computing device;

selecting data samples from the series in accordance with the sampling rate, wherein each data sample is selected at a sampling time instance, using the one or more processors of the mobile computing device; and

determining a discrete data value for each data sample selected from the series of data samples, wherein the discrete data value is determined based on a comparison of a difference between the first signal and the second signal associated with the data sample with respect to a defined threshold, wherein discrete data values represent demodulated digital sensor data, using the one or more processors of the mobile computing device.

23. The method of claim 20, further comprising:

modifying the sampling rate at which to select the data samples in order to account for sampling drift, wherein the sampling drift occurs when a clock in the wearable device drifts from a clock in a mobile computing device demodulating the sensor data; and

applying the modified sampling rate when selecting subsequent data samples from the series of data samples.

24. The method of claim 20, further comprising removing frequency components from the sensor data other than the two frequency tones via a high pass filter.

25. The method of claim 20, further comprising removing frequency components from the sensor data other than the two frequency tones via a finite impulse response (FIR) filter with a cutoff frequency in a range of approximately 9-10 kilohertz (kHz).