Patent Application
20220202297
This application claims priority to Chinese Patent Application No. 201910343291.7, filed with the China National Intellectual Property Administration on Apr. 26, 2019 and entitled “METHOD AND APPARATUS FOR PROCESSING BLOOD PRESSURE MEASUREMENT, AND ELECTRONIC DEVICE”, which is incorporated herein by reference in its entirety.
Embodiments of this application relate to intelligent device technologies, and in particular, to a method and an apparatus for processing blood pressure measurement, and an electronic device.
Blood pressure is lateral pressure of blood on a vascular wall in a unit area when the blood flows in blood vessels. A blood pressure value is an important indicator for measuring a human health condition. Therefore, how to perform blood pressure measurement to provide an accurate blood pressure measurement result is of great significance. Blood pressure measurement methods may be divided into two types: a direct measurement method and an indirect measurement method. The direct measurement method is to percutaneously deliver a long catheter with melted anticoagulants to an aorta, where the catheter is connected to a pressure sensor to directly display blood pressure. The indirect measurement method is mainly to measure blood pressure by using a blood pressure measurement device. Compared with the direct measurement method, the indirect measurement method has advantages of easiness and convenience for operation, and therefore is widely used in various scenarios in which blood pressure measurement needs to be performed. After blood pressure measurement devices have undergone development processes of mercury sphygmomanometers, upper-arm electronic sphygmomanometers, wrist electronic sphygmomanometers, and the like, with continuous development of mobile terminal technologies such as mobile phones, blood pressure measurement devices such as watches and mobile phones with blood pressure measurement functions appear. In this way, a blood pressure measurement technology continuously develops toward directions of portability and miniaturization in combination with consumer electronics.
A mobile phone with a blood pressure measurement function is used as an example. In a conventional technology, when measuring blood pressure by using the mobile phone, a user is required to hold the mobile phone and collect a signal of a specific measured part on a body of the user by using a related sensor on the mobile phone. After collection is performed for a period of time, the mobile phone calculates a blood pressure value based on the collected signal. When blood pressure is collected, it is required that a height of the measured part is kept consistent with that of the heart of the user. Otherwise, a relatively large error may be caused to a measurement result.
However, when the method in the conventional technology is used, usability of a blood pressure measurement device may be relatively low. This further leads to poor user experience.
Embodiments of this application provide a method and an apparatus for processing blood pressure measurement, and an electronic device, so that usability of a blood pressure measurement device can be greatly improved.
A first aspect of the embodiments of this application provides a method for processing blood pressure measurement. In this method, an electronic device obtains a facial feature point of a to-be-measured object; determines a first height difference between the facial feature point and an origin of a second coordinate system based on a first coordinate of the facial feature point in the second coordinate system and a first attitude angle of the second coordinate system relative to a first coordinate system, where a preset point on the electronic device is used as the origin of the second coordinate system; then determines a third height difference between the origin of the second coordinate system and the heart of the object based on the first height difference and a second height difference, where the second height difference is a height difference between the facial feature point and the heart of the object; and further determines blood pressure of the object based on a blood pressure measurement signal of the object collected by a blood pressure measurement signal collection apparatus and the third height difference.
According to the method provided in this embodiment of this application, the facial feature point of the to-be-measured object is obtained, a second coordinate of the facial feature point in the first coordinate system may be obtained based on the first coordinate of the facial feature point in the second coordinate system and the first attitude angle of the second coordinate system relative to the first coordinate system, and the third height difference between the origin of the second coordinate system and the heart of the to-be-measured object may be obtained based on the first height difference that is between the facial feature point and the origin of the second coordinate system and that is identified by the second coordinate, and the second height difference between the facial feature point and the heart of the to-be-measured object. Because a measured part of the to-be-measured object is in contact with the electronic device during blood pressure measurement, a height of the origin of the second coordinate system may be kept consistent with that of the measured part. Correspondingly, the third height difference may represent a height difference between the measured part and the heart. The height difference is exactly a height difference that causes a blood pressure measurement error. Therefore, corresponding compensation processing is further performed based on the third height difference and the signal collected by the blood pressure measurement signal collection apparatus, so that impact of the height difference on a blood pressure measurement result can be eliminated, thereby obtaining an accurate blood pressure measurement result. Therefore, in this embodiment, even if the height of the measured part is inconsistent with that of the heart of the to-be-measured object, an accurate measurement result can be obtained. Therefore, this embodiment can greatly improve usability of a blood pressure measurement device, thereby greatly improving user experience. Moreover, for an electronic device with relatively high space flexibility for a measured part, such as a mobile phone or a watch, after this embodiment is used, because a requirement that the height of the measured part is kept consistent with that of the heart of the user no longer needs to be satisfied, improvement in usability is particularly evident.
In a possible design, before the first height difference between the facial feature point and the origin of the second coordinate system is determined based on the first coordinate of the facial feature point in the second coordinate system and the first attitude angle of the second coordinate system relative to the first coordinate system, the first coordinate of the facial feature point in the second coordinate system may be determined based on a coordinate of the facial feature point in a fourth coordinate system of the electronic device, where a coordinate axis of the fourth coordinate system is collinear with an optical axis, and there is a preset translation amount between the fourth coordinate system and the second coordinate system.
In this possible design, when the facial feature point is a middle point between pupil centers of two eyes of the object, the first coordinate of the facial feature point in the second coordinate system may be determined by using the following process:
collecting a facial image of the to-be-measured object; determining the coordinate of the facial feature point in the fourth coordinate system based on pixel positions of the pupil centers of the two eyes of the to-be-measured object in the facial image; and determining the first coordinate of the facial feature point in the second coordinate system based on the coordinate of the facial feature point in the fourth coordinate system and the translation amount between the fourth coordinate system and the second coordinate system.
In a possible design, before the third height difference between the origin of the second coordinate system and the heart of the object is determined based on the second coordinate and the second height difference, the second height difference may further be first determined.
A method for determining the second height difference may include the following three manners:
In a first manner, there is a preset correspondence between the second height difference and at least one parameter.
In a second manner, configuration parameter information entered by the object is received, where the configuration parameter information includes the second height difference.
In a third manner, a third attitude angle of a third coordinate system relative to the first coordinate system may be determined based on a second attitude angle of the third coordinate system relative to the second coordinate system and the first attitude angle, where the facial feature point is used as an origin of the third coordinate system; then a fourth attitude angle is determined based on a mapping relationship between the third attitude angle and the fourth attitude angle, where the fourth attitude angle is an attitude angle of the torso of the to-be-measured object relative to the first coordinate system; and then the second height difference is determined based on the third attitude angle and the fourth attitude angle.
In the foregoing third manner, when the second height difference is determined based on the third attitude angle and the fourth attitude angle, the second height difference may be determined based on the third attitude angle, the fourth attitude angle, a preset height difference, and preset ratio information, where the preset height difference is a height difference between the facial feature point and the heart of the object when the torso and the head of the object are vertical, and the preset ratio information is a ratio of a height difference between the facial feature point and a neck preset point of the object to the preset height difference when the torso and the head of the object are vertical. Alternatively, the second height difference may be determined based on the third attitude angle, the fourth attitude angle, a height difference between the facial feature point and a neck preset point, and a height difference between the neck preset point and the heart.
An accurate second height difference can be obtained by using any one of the foregoing three manners.
In a possible design, when the blood pressure of the object is determined based on the blood pressure measurement signal of the object collected by the blood pressure measurement signal collection apparatus and the third height difference, a blood pressure compensation value may be determined based on the third height difference; and then the blood pressure of the object is determined based on the blood pressure measurement signal of the object collected by the blood pressure measurement signal collection apparatus and the blood pressure compensation value.
After the blood pressure compensation value obtained based on the third height difference is applied to the blood pressure measurement signal collected by the blood pressure measurement signal collection apparatus, a measurement error generated by a height difference between the measured part and the heart can be greatly reduced.
In a possible design, the blood pressure compensation value may be determined based on the third height difference and a preset blood pressure compensation model, where the blood pressure compensation model is used for representing a correspondence between the third height difference and the blood pressure compensation value.
In a possible design, before the blood pressure compensation value is determined based on the third height difference and the preset blood pressure compensation model, the method further includes:
collecting blood pressure error information under a plurality of third height differences; and
establishing the blood pressure compensation model based on the blood pressure error information under the plurality of third height differences.
In a possible design, whether a height of the electronic device changes when the blood pressure measurement signal collection apparatus collects the blood pressure measurement signal may further be detected, and collecting the blood pressure measurement signal is stopped when the height of the electronic device changes.
A second aspect of the embodiments of this application provides an apparatus for processing blood pressure measurement. The apparatus includes a processing module, where the processing module is configured to: obtain a facial feature point of a to-be-measured object; determine a first height difference between the facial feature point and an origin of a second coordinate system based on a first coordinate of the facial feature point in the second coordinate system and a first attitude angle of the second coordinate system relative to a first coordinate system, where a preset point on an electronic device is used as the origin of the second coordinate system; determine a third height difference between the origin of the second coordinate system and the heart of the object based on the first height difference and a second height difference, where the second height difference is a height difference between the facial feature point and the heart of the object; and determine blood pressure of the object based on a blood pressure measurement signal of the object collected by a blood pressure measurement signal collection apparatus and the third height difference.
In a possible design, the processing module is further configured to:
determine the first coordinate of the facial feature point in the second coordinate system based on a coordinate of the facial feature point in a fourth coordinate system of the electronic device, where a coordinate axis of the fourth coordinate system is collinear with an optical axis, and there is a preset translation amount between the fourth coordinate system and the second coordinate system.
In a possible design, when the facial feature point is a middle point between pupil centers of two eyes of the object, the processing module may be specifically configured to:
collect a facial image of the to-be-measured object;
determine the coordinate of the facial feature point in the fourth coordinate system based on pixel positions of the pupil centers of the two eyes of the to-be-measured object in the facial image; and
determine the first coordinate of the facial feature point in the second coordinate system based on the coordinate of the facial feature point in the fourth coordinate system and the translation amount between the fourth coordinate system and the second coordinate system.
In a possible design, the processing module is further configured to:
determine the second height difference.
In a possible design, there is a preset correspondence between the second height difference and at least one parameter.
In a possible design, the processing module is specifically configured to:
receive configuration parameter information entered by the object, where the configuration parameter information includes the second height difference.
In a possible design, the processing module is specifically configured to:
determine a third attitude angle of a third coordinate system relative to the first coordinate system based on a second attitude angle of the third coordinate system relative to the second coordinate system and the first attitude angle, where the facial feature point is used as an origin of the third coordinate system;
determine a fourth attitude angle based on a mapping relationship between the third attitude angle and the fourth attitude angle, where the fourth attitude angle is an attitude angle of the torso of the to-be-measured object relative to the first coordinate system; and
determine the second height difference based on the third attitude angle and the fourth attitude angle.
In a possible design, the processing module is specifically configured to:
determine the second height difference based on the third attitude angle, the fourth attitude angle, a preset height difference, and preset ratio information, where
the preset height difference is a height difference between the facial feature point and the heart of the object when the torso and the head of the object are vertical, and the preset ratio information is a ratio of a height difference between the facial feature point and a neck preset point of the object to the preset height difference when the torso and the head of the object are vertical.
In a possible design, the processing module is specifically configured to:
determine the second height difference based on the third attitude angle, the fourth attitude angle, a height difference between the facial feature point and a neck preset point, and a height difference between the neck preset point and the heart.
In a possible design, the processing module is specifically configured to:
determine a blood pressure compensation value based on the third height difference; and
determine the blood pressure of the object based on the blood pressure measurement signal of the object collected by the blood pressure measurement signal collection apparatus and the blood pressure compensation value.
In a possible design, the processing module is specifically configured to:
determine the blood pressure compensation value based on the third height difference and a preset blood pressure compensation model, where the blood pressure compensation model is used for representing a correspondence between the third height difference and the blood pressure compensation value.
In a possible design, the processing module is further configured to:
collect blood pressure error information under a plurality of third height differences; and
establish the blood pressure compensation model based on the blood pressure error information under the plurality of third height differences.
In a possible design, the processing module is further configured to:
detect whether a height of the electronic device changes when the blood pressure measurement signal collection apparatus collects the blood pressure measurement signal, and stop collecting the blood pressure measurement signal when the height of the electronic device changes.
For beneficial effects of the apparatus provided in the second aspect and the possible implementations of the second aspect, refer to beneficial effects brought by the first aspect and the possible implementations of the first aspect. Details are not described herein again.
A third aspect of the embodiments of this application provides an electronic device. The electronic device includes a processor and a memory, where the memory is configured to store computer-executable program code, the program code includes instructions, and when the processor executes the instructions, the instructions enable the network device to perform the method according to the first aspect or the possible implementations of the first aspect.
According to a fourth aspect, an embodiment of this application provides a computer program product including instructions. When the computer program product runs on a computer, the computer is enabled to perform the method according to the first aspect or the possible implementations of the first aspect.
According to a fifth aspect, an embodiment of this application provides a computer-readable storage medium. The computer-readable storage medium stores instructions. When the instructions run on a computer, the computer is enabled to perform the method according to the first aspect or the possible implementations of the first aspect.
When a blood pressure measurement device calculates a blood pressure value by collecting a signal of a measured part, a height change of the measured part has relatively large impact on a blood pressure measurement result. To alleviate the impact of the height change of the measured part on the blood pressure measurement result, in a conventional technology, when a user measures blood pressure, it is required that a height of the measured part is kept consistent with that of the heart of the user. For example, when measuring blood pressure by using a mobile phone, the user is required to hold the mobile phone and collect a signal of a specific measured part on the body of the user by using a related sensor on the mobile phone. After collection is performed for a period of time, the mobile phone calculates a blood pressure value based on the collected signal. When blood pressure is collected, it is required that the height of the measured part is kept consistent with that of the heart of the user. Compared with a conventional upper-arm sphygmomanometer, when blood pressure is measured by using an electronic device such as a mobile phone or a watch, space flexibility of the measured part is higher. Therefore, it is more difficult to keep the height of the measured part consistent with that of the heart of the user. Therefore, when the method in the conventional technology is used, usability of the blood pressure measurement device may be relatively low. This further leads to poor user experience. In addition, because it is relatively difficult to keep the height of the measured part consistent with that of the heart of the user, when the method in the conventional technology is used, accuracy of a measurement result is also likely to be low.
The technical solutions provided in the embodiments of this application are intended to resolve the foregoing problem.
The embodiments of this application may be applied to a scenario in which an electronic device is used to measure blood pressure of a to-be-measured object. The electronic device may be any electronic device that has a blood pressure measurement function, for example, a mobile phone, a watch, or a band. A specific form of the electronic device is not limited in the embodiments of this application. The electronic device collects a blood pressure signal by using a blood pressure measurement signal collection apparatus. The blood pressure measurement signal collection apparatus may be a built-in apparatus of the electronic device, or may be an independent external apparatus, and a communication connection is established between the apparatus and the electronic device. The blood pressure measurement signal collection apparatus may be, for example, a blood pressure measurement signal collection sensor. A specific form and a position of the blood pressure measurement signal collection apparatus are not limited in the embodiments of this application. When blood pressure measurement is performed for the to-be-measured object, a contact manner between a measured part of the to-be-measured object and the blood pressure measurement signal collection apparatus may be a manner such as touch or wearing. The contact manner is not specifically limited in the embodiments of this application. In addition, in the embodiments of this application, a camera is disposed on the electronic device, to collect a facial image of the to-be-measured object. The camera may be a front-facing camera, or may be a rear-facing camera. A position of the camera is not specifically limited in the embodiments of this application. Moreover, the camera may be a monocular camera or a multi-view camera, and the camera may use a time of flight (time of flight, ToF) technology, a structured light technology, an RGB color (red, green, blue, RGB) binocular technology, and the like. A quantity and technical structures of cameras are not specifically limited in the embodiments of this application.
In addition, the to-be-measured object to which the embodiments of this application are applicable may be a person, but the embodiments of this application are not limited thereto. The measured part of the to-be-measured object may be a finger, a wrist, an arm, or the like. This is not specifically limited in the embodiments of this application.
To enable a person skilled in the art to better understand the embodiments of this application, the following first explains technical terms used in the embodiments of this application.
1. First Coordinate System
An origin of the first coordinate system is an arbitrarily specified spatial point, three coordinate axes of the first coordinate system are perpendicular to each other, and one of the coordinate axes is vertically upward (a sky direction for short) or downward (a ground direction for short).
It should be noted that, in the embodiments of this application, the other two coordinate axes different from the vertically upward or downward coordinate axis in the first coordinate system may point to any direction in a horizontal plane according to a specified angle.
In an example, one coordinate axis of the first coordinate system points to the sky direction, another coordinate axis points to an east direction, and the rest coordinate axis points to a north direction.
In another example, one coordinate axis of the first coordinate system points to the ground direction, another coordinate axis points to a west direction, and the rest coordinate axis points to a south direction.
In the following embodiments of this application, an example in which the first coordinate system is the coordinate system in the first example is used for description.
2. Second Coordinate System
A particular specified point on the electronic device is used as an origin of the second coordinate system, a first coordinate axis points to a direction of the head of the electronic device, a second coordinate axis points to a screen side of the electronic device, is perpendicular to a screen, and is outward, and a third coordinate axis is perpendicular to the first coordinate axis and the second coordinate axis.
3. Third Coordinate System
The third coordinate system is a coordinate system corresponding to the face of the to-be-measured object, and one coordinate axis of the third coordinate system is perpendicular to a plane formed by a plurality of feature points of the face. The other two coordinate axes of the third coordinate system are perpendicular to the coordinate axis.
4. Fourth Coordinate System
The fourth coordinate system is a coordinate system corresponding to a camera that is disposed on the electronic device and that is configured to collect a facial image, and one coordinate axis of the fourth coordinate system is collinear with an optical axis of the camera. The other two coordinate axes of the fourth coordinate system are perpendicular to the coordinate axis.
Optionally, the three coordinate axes of the fourth coordinate system may be respectively in a same direction as the three coordinate axes of the second coordinate system.
The following describes the technical solutions in the embodiments of this application in detail with reference to specific embodiments. The following several specific embodiments may be combined with each other. Same or similar concepts or processes may not be described in some embodiments.
S101: Obtain a facial feature point of a to-be-measured object.
Optionally, if the to-be-measured object is a person, the facial feature point is a human facial feature point. If the to-be-measured object is another creature, such as a mammal, the facial feature point is a feature point of the face of an animal.
The facial feature point may refer to a specific position of the face. For example, the pupil center of the left eye, the pupil center of the right eye, the middle point of the lower lip, and the middle point between the pupil centers of two eyes may all be used as facial feature points. In this embodiment of this application, one facial feature point may be used, or a plurality of facial feature points may be used.
Optionally, after being started, the electronic device may automatically obtain the facial feature point of the to-be-measured object, or may obtain the facial feature point of the to-be-measured object under a specific trigger condition.
For example, when the electronic device is a mobile phone, a front-facing camera may be disposed on the mobile phone. After a user holding the mobile phone taps an icon of a blood pressure measurement application (application, APP) or taps a specific button for starting blood pressure measurement on the mobile phone, the mobile phone receives a blood pressure measurement indication of the user for the to-be-measured object. In this case, the mobile phone starts the front-facing camera, and the front-facing camera collects a facial image of the to-be-measured object, and extracts the facial feature point from the facial image. In this process, the mobile phone may determine whether the front-facing camera collects facial information required for blood pressure measurement and successfully extracts the preset facial feature point. If the front-facing camera collects the facial information required for blood pressure measurement and successfully extracts the preset facial feature point, the following steps continue to be performed; or if the front-facing camera fails to collect the facial information required for blood pressure measurement or extract the preset facial feature point, the mobile phone may prompt, in a form of voice or a text, the user to adjust an angle of the mobile phone, so that the front-facing camera can collect complete facial information and extract the facial feature point.
In the foregoing example, the user holding the mobile phone and the to-be-measured object may be a same person, or may be different persons.
S102: Determine a first height difference between the facial feature point and an origin of a second coordinate system based on a first coordinate of the facial feature point in the second coordinate system and a first attitude angle of the second coordinate system relative to a first coordinate system, where a preset point on the electronic device is used as the origin of the second coordinate system.
For example, the coordinate point on the electronic device may be a screen center point of the electronic device, or may be a center point of a blood pressure measurement signal collection apparatus on the electronic device. The center point may be specifically a center point of a region that is in contact with a measured part of the to-be-measured object and that is in the blood pressure measurement signal collection apparatus.
In an optional implementation, an origin of the first coordinate system may overlap the origin of the second coordinate system. In this case, a coordinate value of the facial feature point on a coordinate axis pointing to a sky direction or a ground direction in the first coordinate system may be obtained based on the first coordinate and the first attitude angle, where the coordinate value is the first height difference.
In another optional implementation, the origin of the first coordinate system may not overlap the origin of the second coordinate system. In this case, a height difference between the origin of the first coordinate system and the origin of the second coordinate system may be first obtained, and after the coordinate value of the facial feature point on the coordinate axis pointing to the sky direction or the ground direction in the first coordinate system is obtained based on the first coordinate and the first attitude angle, the foregoing origin height difference is eliminated based on the coordinate value, to obtain the first height difference. The height difference between the origin of the first coordinate system and the origin of the second coordinate system may be a preset height difference, or may be a height difference obtained through measurement after the origin of the first coordinate system is selected by the user. This is not specifically limited in this embodiment of this application.
A process of determining the first height difference is described below by using an example in which the origin of the first coordinate system overlaps the origin of the second coordinate system.
S103: Determine a third height difference between the origin of the second coordinate system and the heart of the object based on the first height difference and a second height difference, where the second height difference is a height difference between the facial feature point and the heart of the object.
In addition, refer to
In a specific implementation process, the measured part of the to-be-measured object is in contact with the electronic device, and spatial positions of the origins of the second coordinate system and the first coordinate system relative to the mobile phone may be freely specified and fixed. Therefore, a height of the origin of the second coordinate system may be kept the same as that of the measured part. Therefore, a height difference between the origin of the electronic device and the heart of the to-be-measured object is the third height difference between the measured part and the heart. In this embodiment of this application, the third height difference is denoted as h3. An error during blood pressure measurement is generated by the third height difference h3.
Refer to
S104: Determine blood pressure of the object based on a blood pressure measurement signal of the object collected by the blood pressure measurement signal collection apparatus and the third height difference.
Optionally, based on the blood pressure measurement signal collected by the blood pressure measurement signal collection apparatus, the collected blood pressure measurement signal is processed by using a specific blood pressure measurement algorithm, to obtain original blood pressure, and on this basis, the original blood pressure is compensated based on the third height difference, to obtain an accurate blood pressure value of the to-be-measured object.
In this embodiment, the facial feature point of the to-be-measured object is obtained, a second coordinate of the facial feature point in the first coordinate system may be obtained based on the first coordinate of the facial feature point in the second coordinate system and the first attitude angle of the second coordinate system relative to the first coordinate system, and the third height difference between the origin of the second coordinate system and the heart of the to-be-measured object may be obtained based on the first height difference that is between the facial feature point and the origin of the second coordinate system and that is identified by the second coordinate, and the second height difference between the facial feature point and the heart of the to-be-measured object. Because a measured part of the to-be-measured object is in contact with the electronic device during blood pressure measurement, a height of the origin of the second coordinate system may be kept consistent with that of the measured part. Correspondingly, the third height difference may represent a height difference between the measured part and the heart. The height difference is exactly a height difference that causes a blood pressure measurement error. Therefore, corresponding compensation processing is further performed based on the third height difference and the signal collected by the blood pressure measurement signal collection apparatus, so that impact of the height difference on a blood pressure measurement result can be eliminated, thereby obtaining an accurate blood pressure measurement result. Therefore, in this embodiment, even if the height of the measured part is inconsistent with that of the heart of the to-be-measured object, an accurate measurement result can be obtained. Therefore, this embodiment can greatly improve usability of a blood pressure measurement device, thereby greatly improving user experience. Moreover, for an electronic device with relatively high space flexibility for a measured part, such as a mobile phone or a watch, after this embodiment is used, because a requirement that the height of the measured part is kept consistent with that of the heart of the user no longer needs to be satisfied, improvement in usability is particularly evident.
In an optional implementation, before the second coordinate is determined by using the first coordinate and the first attitude angle in step S102, the first coordinate and the first attitude angle may be first determined.
The first attitude angle represents an attitude angle of the second coordinate system relative to the first coordinate system, as described above. In this embodiment of this application, the first attitude angle may include a pitch angle, a roll angle, and a yaw angle, or may include only a pitch angle and a roll angle. When the first attitude angle is determined, in an optional implementation, the first attitude angle may be determined by using a specific software interface, and the electronic device reads the first attitude angle by using the software interface. In another optional implementation, data of a micro-electro mechanical system (micro-electro mechanical system, MEMS) sensor, a magnetometer, and the like in the electronic device may be collected, and the collected data is calculated, to obtain the attitude angle of the second coordinate system relative to the first coordinate system.
The first coordinate of the facial feature point in the second coordinate system may be determined based on a coordinate of the facial feature point in a fourth coordinate system of the electronic device. Optionally, a lens optical center of a camera that collects a facial image in the electronic device may be used as an origin of the fourth coordinate system, three coordinate axes of the fourth coordinate system are respectively in a same direction as the three coordinate axes of the second coordinate system, and there is a preset translation amount between the fourth coordinate system and the second coordinate system.
The following describes, by using an example in which the facial feature point is a middle point between pupil centers of two eyes, a process of determining the first coordinate of the facial feature point in the second coordinate system based on the coordinate of the facial feature point in the fourth coordinate system of the electronic device.
S401: Collect the facial image of the to-be-measured object.
Optionally, when the camera of the electronic device collects the facial image of the to-be-measured object, a complete facial image may be collected, or a partial facial image including the facial feature point may be collected.
S402: Determine the coordinate of the facial feature point in the fourth coordinate system based on pixel positions of the pupil centers of the two eyes of the to-be-measured object in the facial image.
Optionally, after the facial image of the to-be-measured object is collected, pixel coordinates of the pupil centers of the two eyes in the facial image may be recognized by using an image recognition method. Based on a point distance between pixels in the facial image, a camera focal length, a pupil distance of the two eyes, and the triangle similarity theorem, the coordinate of the facial feature point in the fourth coordinate system can be further determined.
S403: Determine the first coordinate of the facial feature point in the second coordinate system based on the coordinate of the facial feature point in the fourth coordinate system and the translation amount between the fourth coordinate system and the second coordinate system.
The following further explains the foregoing processing process with reference to a figure.
Further, in the example shown in
After the coordinate value (xc, yc, zc) of the middle point em between the pupil centers of the two eyes in the fourth coordinate system is obtained, a translation vector T=[xcs, ycs, zcs] from the fourth coordinate system to the second coordinate system may be determined based on the structural size of the mobile phone, and based on a coordinate transformation relationship of a spatial point between different coordinate systems, the first coordinate (xs, ys, zs) of the facial feature point in the second coordinate system can be obtained through summation based on the coordinate of the facial feature point in the fourth coordinate system and the translation vector.
It should be noted that
In addition to the foregoing example, in a case when the facial feature point is another point, the first coordinate may also be determined by using a method similar to the foregoing processing process. For example, when the facial feature point is the pupil center of the left eye of the to-be-measured object, the coordinate of the pupil center of the left eye in the fourth coordinate system may be first determined by using the foregoing method, and based on the translation amount between the fourth coordinate system and the second coordinate system, the first coordinate of the pupil center of the left eye in the second coordinate system is further calculated.
It should be noted that, when the first coordinate of the facial feature point in the second coordinate system is determined based on the coordinate of the facial feature point in the fourth coordinate system, a method for determining the coordinate of the facial feature point in the fourth coordinate system is described by using the monocular front-facing camera as an example. In a specific implementation process, the coordinate of the facial feature point in the fourth coordinate system may alternatively be determined based on a multi-view camera, and the camera may use a ToF technology, a structured light technology, an RGB binocular technology, and the like. In addition, the camera in this embodiment of this application may be a front-facing camera, or may be rear-facing camera. A position of the camera on the electronic device is not limited in this embodiment of this application.
Some optional implementations of determining the first coordinate and the first attitude angle are described above. The second coordinate of the facial feature point in the first coordinate system may be determined based on the first coordinate and the first attitude angle, and the third height difference is determined based on the second height difference and the first height difference that is identified by the second coordinate.
As described above, the second height difference represents the height difference between the facial feature point and the heart of the to-be-measured object. The second height difference may be first determined before the third height difference is determined based on the second height difference and the second coordinate.
In an optional implementation, there is a preset correspondence between the second height difference and at least one parameter.
The at least one parameter is a known parameter, and may be obtained in advance in a manner such as user input, or automatic measurement by the electronic device. The at least one parameter may include the gender, height, weight, and the like of the to-be-measured object.
For example, second height difference information under different genders and heights may be obtained in advance through statistics collection with reference to a large quantity of samples, and processing such as averaging is performed on the statistical information, to obtain information about correspondences between genders and different heights and the second height difference. Further, in this embodiment of this application, before blood pressure measurement is performed, the user may be reminded to first enter gender and/or height information of the to-be-measured object, and further, the second height difference is obtained based on the correspondences between genders/heights and the second height difference.
In another optional implementation, the electronic device may further remind the user to measure the second height difference of the to-be-measured object, and enter the measured second height difference. The electronic device may directly use the second height difference. In this implementation, before performing blood pressure measurement, the electronic device may remind the user to manually enter the second height difference. In addition, the user may further enter another parameter, for example, the pupil distance of the two eyes of the to-be-measured object, for use in the foregoing processing process in this embodiment of this application.
In addition to the foregoing two optional implementations, the second height difference may alternatively be a default value. The electronic device pre-stores the default value. In this embodiment of this application, the second height difference is directly obtained, and the third height difference is determined based on the second height difference.
The foregoing optional implementations may be used for a case in which measurement is performed on the to-be-measured object in a posture in which the torso and the head are perpendicular to a ground.
In a specific implementation process, the posture of the to-be-measured object may be the posture in which the torso and the head are perpendicular to the ground shown in
There is an error between the second height difference when the posture of the to-be-measured object is the posture in which the torso or the head is not perpendicular to the ground and the second height difference when a standard measurement posture is present, and the error of the second height difference can be greatly reduced in the following optional implementations, so that an accurate second height difference can be obtained in various postures of the to-be-measured object.
S801: Determine a third attitude angle of a third coordinate system relative to the first coordinate system based on a second attitude angle of the third coordinate system relative to the second coordinate system and the first attitude angle, where the facial feature point is used as an origin of the third coordinate system.
Optionally, when the plurality of facial feature points of the to-be-measured object are selected, a plurality of feature points that are not on a same straight line may be selected, and a quantity of the selected feature points may be, for example, 3 or a value greater than 3.
On the basis of obtaining the second attitude angle and the first attitude angle, optionally, the third attitude angle of the third coordinate system relative to the first coordinate system may be determined through rotation transformation.
S802: Determine a fourth attitude angle based on a mapping relationship between the third attitude angle and the fourth attitude angle, where the fourth attitude angle is an attitude angle of the torso of the to-be-measured object relative to the first coordinate system.
For example, the to-be-measured object is a person. In different postures of the person, probability distributions of the third attitude angle and the fourth attitude angle satisfy correspondences of probability statistical distributions. For example, during blood pressure measurement by using a mobile phone, a person is usually used to sitting upright and holding the mobile phone at a position below the head, and at the same time, the human face is tilted downward by a particular angle to view the screen or is approximately facing forward. This posture corresponds to the posture shown in
Based on the foregoing correspondence, the mapping relationship between the third attitude angle and the fourth attitude angle may be constructed. Optionally, the mapping relationship between the third attitude angle and the fourth attitude angle may be constructed by using a mathematical model of a probability distribution function or a mapping relationship table of the probability distribution function. Table 1 below is an example of a mapping relationship table between the third attitude angle and a probability distribution function of the fourth attitude angle. As shown in Table 1, a specific third attitude angle corresponds to a probability distribution function using the third attitude angle as a parameter, and a fourth attitude angle may be obtained based on the function.
S803: Determine the second height difference based on the third attitude angle and the fourth attitude angle.
In an optional implementation, the second height difference may be determined based on the third attitude angle, the fourth attitude angle, a preset height difference, and preset ratio information. The preset height difference is a height difference between the facial feature point and the heart of the to-be-measured object when the torso and the head of the to-be-measured object are vertical, and the preset ratio information is a ratio of a height difference between the facial feature point and a neck preset point of the to-be-measured object to the preset height difference when the torso and the head of the to-be-measured object are vertical.
For example, the neck preset point may be a rotation center of the neck relative to the torso when the head of the to-be-measured object moves.
Still refer to
In another optional implementation, the second height difference may alternatively be determined based on the third attitude angle, the fourth attitude angle, the height difference between the facial feature point and the neck preset point, and the height difference between the neck preset point and the heart.
Some optional implementations of determining the second height difference are described above. The third height difference may be determined based on the second height difference and the foregoing second coordinate.
It can be learned from the foregoing that the third height difference is the height difference between the origin of the second coordinate system and the heart of the to-be-measured object, and the third height difference affects accuracy of the blood pressure measurement result. Therefore, the blood pressure measurement result obtained based on the signal collected by the blood pressure measurement signal collection apparatus may be compensated based on the third height difference, to obtain an accurate blood pressure measurement result.
S1101: Determine a blood pressure compensation value based on the third height difference.
Optionally, the blood pressure compensation value may be determined based on the third height difference and a preset blood pressure compensation model. The blood pressure compensation model is used for representing a correspondence between the third height difference and the blood pressure compensation value.
In an example, the blood pressure compensation model may be established based on an internal relationship in which a height change of the electronic device relative to the heart causes a change to vascular blood pressure of the part on which blood pressure measurement is performed.
In another example, the blood pressure compensation model may be established based on actual measurement data. Specifically, blood pressure error information under a plurality of third height differences is first collected, and the blood pressure compensation model is further established based on the blood pressure error information under the plurality of third height differences. Optionally, a method for establishing the blood pressure compensation model may include: calculating an average value of blood pressure error data corresponding to each of the third height differences, or calculating a probability density function of the blood pressure error data corresponding to each of the third height differences, calculating an expected error value based on the probability density function, and performing function fitting for all the third height differences and corresponding expected error values of blood pressure. The function obtained through fitting is the blood pressure compensation model.
S1102: Determine the blood pressure of the to-be-measured object based on the blood pressure measurement signal of the to-be-measured object collected by the blood pressure measurement signal collection apparatus and the blood pressure compensation value.
After the blood pressure measurement signal collection apparatus collects the blood pressure measurement signal, the electronic device may obtain a blood pressure measurement value by processing the signal. On this basis, accurate blood pressure of the to-be-measured object may be obtained by superimposing the blood pressure measurement value and the blood pressure compensation value.
It should be noted that the blood pressure compensation value may be a positive value or a negative value.
In a specific implementation process, in a process of measuring blood pressure of the to-be-measured object by using the method in this embodiment of this application, a posture of the to-be-measured object should be kept consistent. To be specific, after the third height difference is calculated by using the method in this embodiment of this application, the third height difference should be kept unchanged, to ensure an accurate compensation result. Correspondingly, in the process of measuring the blood pressure of the to-be-measured object, the electronic device may detect, based on a specific periodicity, whether a height of the electronic device changes when the blood pressure measurement signal collection apparatus collects the blood pressure measurement signal, and if the height of the electronic device changes when the blood pressure measurement signal collection apparatus collects the blood pressure measurement signal, the blood pressure measurement signal collection apparatus stops collecting the blood pressure measurement signal. At the same time, the user is prompted that measurement is stopped and the user should keep the same posture during next measurement. Optionally, the electronic device may detect, by using a motion sensor, a barometer, or the like, whether the foregoing height changes.
The processing module is configured to: obtain a facial feature point of a to-be-measured object;
determine a first height difference between the facial feature point and an origin of a second coordinate system based on a first coordinate of the facial feature point in the second coordinate system and a first attitude angle of the second coordinate system relative to a first coordinate system, where a preset point on an electronic device is used as the origin of the second coordinate system;
determine a third height difference between the origin of the second coordinate system and the heart of the object based on the first height difference and a second height difference, where the second height difference is a height difference between the facial feature point and the heart of the object; and
determine blood pressure of the object based on a blood pressure measurement signal of the object collected by a blood pressure measurement signal collection apparatus and the third height difference.
Optionally, the apparatus further includes a sending module 1202 and a receiving module 1203. The sending module 1202 is configured to send information to an external device, and the receiving module 1203 is configured to receive information sent by the external device or entered by a user.
In a possible implementation, the processing module 1201 is further configured to:
determine the first coordinate of the facial feature point in the second coordinate system based on a coordinate of the facial feature point in a fourth coordinate system of the electronic device, where a coordinate axis of the fourth coordinate system is collinear with an optical axis, and there is a preset translation amount between the fourth coordinate system and the second coordinate system.
In a possible implementation, when the facial feature point is the middle point between pupil centers of two eyes of the object, the processing module 1201 may be specifically configured to:
collect a facial image of the to-be-measured object;
determine the coordinate of the facial feature point in the fourth coordinate system based on pixel positions of the pupil centers of the two eyes of the to-be-measured object in the facial image; and
determine the first coordinate of the facial feature point in the second coordinate system based on the coordinate of the facial feature point in the fourth coordinate system and the translation amount between the fourth coordinate system and the second coordinate system.
In a possible implementation, the processing module 1201 is further configured to:
determine the second height difference.
In a possible implementation, there is a preset correspondence between the second height difference and at least one parameter.
In a possible implementation, the processing module 1201 is specifically configured to:
receive configuration parameter information entered by the object, where the configuration parameter information includes the second height difference.
In a possible implementation, the processing module 1201 is specifically configured to:
determine a third attitude angle of a third coordinate system relative to the first coordinate system based on a second attitude angle of the third coordinate system relative to the second coordinate system and the first attitude angle, where the facial feature point is used as an origin of the third coordinate system;
determine a fourth attitude angle based on a mapping relationship between the third attitude angle and the fourth attitude angle, where the fourth attitude angle is an attitude angle of the torso of the to-be-measured object relative to the first coordinate system; and
determine the second height difference based on the third attitude angle and the fourth attitude angle.
In a possible implementation, the processing module 1201 is specifically configured to:
determine the second height difference based on the third attitude angle, the fourth attitude angle, a preset height difference, and preset ratio information, where
the preset height difference is a height difference between the facial feature point and the heart of the object when the torso and the head of the object are vertical, and the preset ratio information is a ratio of a height difference between the facial feature point and a neck preset point of the object to the preset height difference when the torso and the head of the object are vertical.
In a possible implementation, the processing module 1201 is specifically configured to:
determine the second height difference based on the third attitude angle, the fourth attitude angle, a height difference between the facial feature point and a neck preset point, and a height difference between the neck preset point and the heart.
In a possible implementation, the processing module 1201 is specifically configured to:
determine a blood pressure compensation value based on the third height difference; and
determine the blood pressure of the object based on the blood pressure measurement signal of the object collected by the blood pressure measurement signal collection apparatus and the blood pressure compensation value.
In a possible implementation, the processing module 1201 is specifically configured to:
determine the blood pressure compensation value based on the third height difference and a preset blood pressure compensation model, where the blood pressure compensation model is used for representing a correspondence between the third height difference and the blood pressure compensation value.
In a possible implementation, the processing module 1201 is further configured to:
collect blood pressure error information under a plurality of third height differences; and
establish the blood pressure compensation model based on the blood pressure error information under the plurality of third height differences.
In a possible implementation, the processing module 1201 is further configured to:
detect whether a height of the electronic device changes when the blood pressure measurement signal collection apparatus collects the blood pressure measurement signal, and stop collecting the blood pressure measurement signal when the height of the electronic device changes.
The apparatus for processing blood pressure measurement provided in this embodiment of this application may execute actions of the electronic device in the foregoing method embodiment. Implementation principles and technical effects of the apparatus for processing blood pressure measurement are similar to those of the electronic device, and are not described herein again.
It should be noted that, it should be understood that division of the modules of the foregoing apparatus is merely division of logical functions, and in actual implementation, all or some modules may be integrated into one physical entity, or may be physically separated. In addition, all of these modules may be implemented in a form of invoking software by processing elements; or all of these modules may be implemented in a form of hardware; or some modules are implemented in a form of invoking software by processing elements, and some modules are implemented in a form of hardware. For example, the processing module may be a separately disposed processing element, or may be integrated into a chip of the foregoing apparatus for implementation. In addition, the processing module may alternatively be stored in a memory of the foregoing apparatus in a form of program code, and a processing element of the foregoing apparatus invokes and executes a function of the foregoing determining module. Implementation of other modules is similar to that of the processing module. In addition, all or some of these modules may be integrated together, or may be implemented separately. The processing element described herein may be an integrated circuit having a signal processing capability. In an implementation process, the steps of the foregoing method or the foregoing modules may be completed by using an integrated logic circuit of hardware in the processing elements or instructions in a form of software.
For example, the foregoing modules may be one or more integrated circuits configured to implement the foregoing method, for example, one or more application-specific integrated circuits (application-specific integrated circuits, ASICs), or one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (field programmable gate arrays, FPGAs), or the like. In another example, when one of the foregoing modules is implemented in a form of invoking program code by a processing element, the processing element may be a general-purpose processor, for example, a central processing unit (central processing unit, CPU) or another processor that can invoke the program code. In another example, these modules may be integrated together and implemented in a form of a system-on-a-chip (system-on-a-chip, SOC).
In the foregoing embodiment, the modules may be entirely or partially implemented by using software, hardware, firmware, or any combination thereof. When software is used for implementation, the modules may be entirely or partially implemented in a form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, procedures or functions according to the embodiments of this application are entirely or partially generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or another programmable apparatus. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (for example, a coaxial cable, an optical fiber, or a digital subscriber line (DSL)) or wireless (for example, infrared, wireless, or microwaves) manner. The computer-readable storage medium may be any usable medium that can be accessed by the computer, or a data storage device such as a server or a data center that integrates one or more usable media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, or a magnetic tape), an optical medium (for example, a DVD), a semiconductor medium (for example, a solid state disk (SSD)), or the like.
The system bus mentioned in
The processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (network processor, NP), and the like. The processor may alternatively be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or another programmable logic device, a discrete gate or a transistor logic device, or a discrete hardware component.
Optionally, an embodiment of this application further provides a storage medium. The storage medium stores instructions. When the instructions run on a computer, the computer is enabled to perform the method in the embodiment shown in
Optionally, an embodiment of this application further provides a chip for running an instruction. The chip is configured to perform the method in the embodiment shown in
An embodiment of this application further provides a program product. The program product includes computer programs. The computer programs are stored in a storage medium. At least one processor may read the computer programs from the storage medium. When the at least one processor executes the computer programs, the method in the embodiment shown in
In the embodiments of this application, “at least one” means one or more, and “a plurality of” means two or more. “And/or” describes an association relationship between associated objects, and represents that three relationships may exist. For example, A and/or B may represent: Only A exists, both A and B exist, and only B exists, where A and B may be singular or plural. The character “/” generally indicates that the associated objects are in an “or” relationship. In a formula, the character “/” indicates that the associated objects are in a “division” relationship. “At least one of the following items” or its similar expressions mean any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, and c may represent a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c may be singular or plural.
It may be understood that various numeric numbers in the embodiments of this application are merely distinguished for ease of description, and are not intended to limit the scope of the embodiments of this application.
It may be understood that, in the embodiments of this application, sequence numbers of the foregoing processes do not mean execution sequences. The execution sequences of the processes should be determined based on functions and internal logic of the processes, and should not constitute any limitation on the implementation processes of the embodiments of this application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201910343291.7 | Apr 2019 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/085509 | 4/20/2020 | WO | 00 |
