Bio-processor, bio-signal detecting system, and operation method of bio-processor

1. A bio-processor, comprising:

a bioelectrical impedance sensor electrically connected to electrodes, the bioelectrical impedance sensor configured to measure changes in bioelectrical impedance by sensing a sensing voltage to generate a measured bioelectrical impedance; and

a digital signal processor configured to,

estimate, during a settling time, a settled bioelectrical impedance value corresponding to a settled time after expiration of the settling time by,

measuring, via the bioelectrical impedance sensor, the measured bioelectrical impedance during a sensing time corresponding to a portion of the settling time shorter than an entirety of the settling time, the settling time being prior to the measured bioelectrical impedance reaching the settled bioelectrical impedance value at the settled time, and

compensating for the sensing time being shorter than the entirety of the settling time by digitally modeling the value of the measured bioelectrical impedance for the settling time in a fitting function based on changes in the sensing voltage to generate a modeled fitting function, and estimating the settled bioelectrical impedance value at the settled time based on the modeled fitting function, and

generate bio-data based on the estimated settled bioelectrical impedance value.

2. The bio-processor of claim 1 , wherein the digital signal processor is configured to:

calculate a time when the measured bioelectrical impedance is settled from the modeled fitting function; and

estimate the settled bioelectrical impedance value based on the time.

3. The bio-processor of claim 1 , wherein the modeled fitting function is a natural logarithmic function.

4. The bio-processor of claim 1 , wherein the digital signal processor is configured to:

determine a contact error between the electrodes and a user by comparing the modeled fitting function with the changes in the measured bioelectrical impedance.

5. The bio-processor of claim 1 , wherein the digital signal processor is configured to:

generate the bio-data based on a parameter included in the settled bioelectrical impedance value such that the bio-data generated by the digital signal processor includes body fat data.

6. The bio-processor of claim 5 , further comprising:

a nonvolatile memory configured to store parameter data and regression data, the parameter data including information about a value of the parameter and the regression data including data used to calculate the bio-data from the value of the parameter.

7. The bio-processor of claim 1 , further comprising:

a Galvanic skin response sensor configured to measure an electric skin resistance by a Galvanic skin response before expiration of the settling time,

wherein the digital signal processor is configured to:

estimate a contact resistance value after the settling time based on the electric skin resistance; and

adjust the settled bioelectrical impedance value based on the contact resistance value to generate a compensated settled bioelectrical impedance value.

8. The bio-processor of claim 1 , wherein the digital signal processor comprises:

a modeling circuit configured to model the changes in the measured bioelectrical impedance in the fitting function to generate the modeled fitting function;

an error detecting circuit configured to generate a contact error data by comparing the modeled fitting function with the changes in the measured bioelectrical impedance; and

an impedance compensation circuit configured to calculate the settled bioelectrical impedance value based on the modeled fitting function.

9. A bio-signal detecting system, the bio-signal detecting system comprising:

an electrode device configured to supply an output current to outside the bio-signal detecting system, and to receive a sensing voltage based on the output current;

a bioelectrical impedance sensor electrically connected to the electrode device, the bioelectrical impedance sensor configured to measure changes in bioelectrical impedance by sensing the sensing voltage to generate a measured bioelectrical impedance; and

a processor configured to,

estimate, during a settling time, a settled bioelectrical impedance value corresponding to a settled time after expiration of the settling time by,

measuring, via the bioelectrical impedance sensor, the measured bioelectrical impedance during a sensing time corresponding to a portion of the settling time shorter than an entirety of the settling time, the settling time being prior to the measured bioelectrical impedance reaching the settled bioelectrical impedance value at the settled time, and

compensating for the sensing time being shorter than the entirety of the settling time by digitally modeling the value of the measured bioelectrical impedance for the settling time in a fitting function based on changes in the sensing voltage to generate a modeled fitting function, and estimating the settled bioelectrical impedance value at the settled time based on the modeled fitting function, and

generate bio-data based on the estimated settled bioelectrical impedance value.

10. The bio-signal detecting system of claim 9 , wherein the processor is configured to:

output the bio-data through a host interface.

11. The bio-signal detecting system of claim 9 , wherein the bioelectrical impedance sensor is configured to:

generate a bioelectrical impedance signal based on the sensing voltage; and

output the bioelectrical impedance signal through a host interface, the processor is configured to:

estimate the settled bioelectrical impedance value based on the bioelectrical impedance signal.

12. The bio-signal detecting system of claim 9 , wherein

the output current includes a first output current and a second output current,

the sensing voltage includes a first sensing voltage and a second sensing voltage, and

the electrode device includes,

a first electrode configured to receive the first sensing voltage;

a second electrode configured adjacent to the first electrode, the second electrode configured to output the first output current;

a third electrode configured to receive the second sensing voltage; and

a fourth electrode configured adjacent to the third electrode, the fourth electrode configured to output the second output current.

13. The bio-signal detecting system of claim 12 , further comprising:

a Galvanic skin response sensor configured to,

receive a first Galvanic voltage from the third electrode,

receive a second Galvanic voltage from the fourth electrode, and

measure electric skin resistance based on the first Galvanic voltage and the second Galvanic voltage.

14. The bio-signal detecting system of claim 9 , further comprising:

a Galvanic skin response sensor configured to sense a Galvanic voltage from the electrode device, and to measure electric skin resistance based on the Galvanic voltage,

wherein the processor is configured to:

calculate body fat data based on the settled bioelectrical impedance value; and

adjust the body fat data based on the measured electric skin resistance to generate a compensated settled bioelectrical impedance value.

15. The bio-signal detecting system of claim 9 , further comprising:

a Galvanic skin response sensor configured to sense a Galvanic voltage from the electrode device, and to measure electric skin resistance based on the Galvanic voltage,

wherein the processor is configured to:

predict the settling time based on the measured electric skin resistance and the changes in the measured bioelectrical impedance to generate a predicted settling time; and

estimate the settled bioelectrical impedance value based on the predicted settling time.

16. The bio-signal detecting system of claim 9 , further comprising:

a Galvanic skin response sensor configured to sense a Galvanic voltage from the electrode device, and to measure an electric skin resistance based on the Galvanic voltage,

wherein the processor is configured to:

estimate a contact time between the electrode device and a user based on the electric skin resistance; and

estimate the settled bioelectrical impedance value based on the changes in the measured bioelectrical impedance and the contact time.

17. An operation method of a bio-processor, the method comprising:

estimating, during a settling time, a settled bioelectrical impedance value corresponding to a settled time after expiration of the settling time by,

measuring, via a bioelectrical impedance sensor electrically connected to electrodes, a measured bioelectrical impedance based on a value of a sensing voltage during a sensing time corresponding to a portion of the settling time shorter than an entirety of the settling time, the settling time being prior to the measured bioelectrical impedance reaching the settled bioelectrical impedance value at the settled time, and

compensating for the sensing time being shorter than the entirety of the settling time by digitally modeling the value of the measured bioelectrical impedance for the settling time in a fitting function based on changes in the sensing voltage to generate a modeled fitting function, and estimating the settled bioelectrical impedance value at the settled time based on the modeled fitting function; and

generating bio-data based on the estimated settled bioelectrical impedance value.

18. The operation method of claim 17 , further comprising:

determining a contact error between the bioelectrical impedance sensor and a user by comparing the modeled fitting function with the value of the measured bioelectrical impedance.