CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2018-0138370, filed on Nov. 12, 2018, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

1) Field

The disclosure relates to a method and a device for detecting a blood pressure calibration time point.

2) Description of Related Art

As interests of the users in health have increased, various kinds of biometric information measuring devices have been developed. The methods for measuring biometric information may be largely classified into an invasive measurement method and a noninvasive measurement method. The noninvasive measurement methods, by which a pulse can be simply detected while pain is not caused to the user, have been widely used. For example, the noninvasive blood pressure measurement methods are methods for calculating a blood pressure without using a cuff, and may include pulse wave analysis (PWA), pulse wave velocity (PWV), and tonometry.

For example, the pulse wave analysis (PWA) is a method of estimating a blood pressure value based on the shapes of the waveforms measured in an optical scheme. The pulse waveform velocity (PWV) is a method of disposing sensors at different location of an artery and using a time interval between the pulses measured at two points. The tonometry is a method of disposing a pressure sensor on an artery at a base of a wrist, measuring the arterial pressure thereat, and estimating the blood pressure value of the coronary artery using the measured arterial pressure. Because all of the three listed methods are methods for indirectly estimating a blood pressure without directly actually measuring a blood pressure value of a coronary artery, a process of calibrating the results of the algorithms by a systolic blood pressure (SBP) and a diastolic blood pressure (DBP) which are actual blood pressure values is required.

Recently, with the development of digital technologies, various types of electronic devices have been widely utilized, such as, mobile communication terminals, personal digital assistants (PDA), electronic organizers, smart phones, tablet personal computers (PC), wearable devices, and the like. Further, the electronic device has continuously improved hardware parts and/or software parts thereof in order to support and increase functions. As an example, the electronic devices such as wearable devices are utilized as devices for measuring biometric information because they contact the human bodies of the users. The electronic devices calculate the blood pressure values of users and guide the measured blood pressure values to the users, and thus can allow the user to easily recognize to which degree the blood pressure of the user corresponds.

The blood pressure calibration may be a calibration which is performed on the result of the cuff-less hemodynamometer with a blood pressure measured by a cuff hemodynamometer after the blood pressure reference equipment (e.g. the cuff hemodynamometer) and the cuff-less hemodynamometer are operated simultaneously or sequentially. If the blood pressure calibration is not made, the user cannot obtain a precise blood pressure value in the cuff-less hemodynamometer, and thus may not detect a change of blood pressure, in particular, an abrupt increase of the blood pressure. The user has to input the blood pressure value measured by the cuff hemodynamometer when the blood pressure value is calculated first in the cuff-less hemodynamometer, and after then, the measurement of the blood pressure may be requested to be made again if the blood pressures measured by the cuff hemodynamometer and the cuff-less hemodynamometer are different by a preset value.

The proper time points of the blood pressure calibrations are different for different users, and may vary according to the body change degrees of the users. Accordingly, it may be difficult for the user to accurately recognize the blood pressure calibration time point of the user. This is because it may be necessary to calibrate the blood pressure at an interval of one month, one week, or one day according to the change of the body of the user, the mounting location of the wearable device, and a change in the mounting degree. Currently, in the cuff-less hemodynamometer, the calibration time point is informed of to all the users based on the experimental results of the manufacturer that manufactured the cuff-less hemodynamometer, and the user may fail to calibrate the blood pressure at a necessary time point or may have to further perform an unnecessary calibration operation.

Moreover, because the cuff-less hemodynamometer has to be used each time in order to recognize a more precise blood pressure calibration time point, it may be difficult to achieve the purpose of use of the cuff-less hemodynamometer. The user uses the cuff-less hemodynamometer to reduce disadvantages, such as inconveniences of the cuff hemodynamometer and inconveniences of movement of a device, and it may not be meaningful to use cuff-less hemodynamometer if the cuff hemodynamometer is frequently used to recognize a precise blood pressure correction time point.

The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure.

SUMMARY

According to various embodiments, a method and a device for detecting and guiding a personalized blood pressure calibration time point by monitoring a difference between blood pressures measured by two different blood pressure measuring methods are disclosed.

In accordance with an example aspect of the disclosure, an electronic device includes housing, a user interface comprising interface circuitry disposed in a first part of the housing, a photoplethysmogram (PPG) sensor disposed to be exposed through a second part of the housing, the PPG sensor configured to calculate a blood pressure value while contacting a portion of a body of a user, at least one sensor, a wireless communication circuit disposed in the interior of the housing, a processor disposed in the interior of the housing, and operatively connected to the user interface, the PPG sensor, the at least one sensor, and the wireless communication circuit, and a memory operatively connected to the processor, wherein the memory stores instructions that, when executed by the processor, control the electronic device to: receive first data from the at least one sensor, receive second data from the PPG sensor based at least in part on the received first data, determine a pulse arrival time (PAT) value, a heart rate (HR) value, and a pulse transit time (PTT) value from the second data, calculate a first blood pressure value (BP1) and a second blood pressure value (BP2) by applying the determined values to pulse wave velocity (PWV) algorithms, wherein BP1≅a1PAT+b1HR+c1, BP2≅a2ln(PTT)+b2, wherein, a1, a2, b1, b2, and c1are constant values for matching blood pressure values measured during calibration with blood pressure values measured by a cuff hemodynamometer, determine a calibration time point based at least in part on a difference between the first blood pressure value and the second blood pressure value, and provide guide information related to the calibration time point through the user interface based at least in part on the determination.

In accordance with another example aspect of the disclosure, an electronic device includes a housing, a user interface comprising interface circuitry disposed in a first part of the housing, a photoplethysmogram (PPG) sensor disposed to be exposed through a second part of the housing, the PPG sensor configured to calculate a blood pressure value while facing a portion of a body of a user, a wireless communication circuit disposed in the interior of the housing, a processor disposed in the interior of the housing and operatively connected to the user interface, the PPG sensor, and the wireless communication circuit, and a memory operatively connected to the processor, wherein the memory stores instructions that, when executed by the processor, control the electronic device to: receive data from the PPG sensor, determine a pulse arrival time (PAT) value, an heart rate (HR) value, and a pulse transit time (PTT) value from the data, calculate a first blood pressure value and a second blood pressure value by applying the determined values to a first pulse wave velocity (PWV) algorithm using the PAT value and the HR value and a second PWV algorithm using the PTT value, determine whether a calibration is necessary based at least in part on a difference between the first blood pressure value and the second blood pressure value, and provide information related to the calibration through the user interface based at least in part on the determination.

In accordance with another example aspect of the disclosure, an electronic device includes a housing, a user interface disposed in a first part of the housing, a photoplethysmogram (PPG) sensor disposed to be exposed through a second part of the housing, the PPG sensor configured to calculate a blood pressure value while contacting a portion of a body of a user, a wireless communication circuit disposed in the interior of the housing, a processor disposed in the interior of the housing, and operatively connected to the user interface, the PPG sensor, and the wireless communication circuit, and a memory operatively connected to the processor, wherein the memory stores instructions that, when executed by the processor, control the electronic device to: receive data from the PPG sensor, determine a pulse transit time (PTT) value, a cardiac output (CO) value, and a total peripheral resistance (TPR) value from the data, calculate a first blood pressure value and a second blood pressure by applying the determined values to a first pulse wave velocity (PWV) algorithm using the PTT value and a second pulse wave analysis (PWA) algorithm using the CO value and the TPR value, determine whether a calibration is necessary based at least in part on a difference between the first blood pressure value and the second blood pressure value, and provide information related to the calibration through the user interface based at least in part on the determination.

