Measurements of blood pressure and edema, for example, as an indication of increased likelihood of preeclampsia

Abstract

A system includes a first sensor to generate a swelling signal based on a user pressing the first sensor with a body part, a second sensor to generate a blood signal indicative of a volume of blood in the body part when the user presses the first sensor, and a force sensor to measure a force applied to the first sensor by the body part when the user presses the first sensor. The system also includes a processor configured to determine an indication of swelling of the body part based on the swelling signal when the force sensor measures a first predetermined value, and determine an indication of blood pressure at the body part based on a force value measured by the force sensor when the blood signal reaches a second predetermined value.

Description

Technical Field

[0001] This invention relates to systems and methods for measuring blood pressure and edema, for example, as an indicator of the likelihood of an increase in preeclampsia. In particular, this invention relates to indications for swelling and blood pressure associated with preeclampsia. Background Technology

[0002] Preeclampsia affects 5-10% of pregnancies and causes significant maternal and fetal morbidity and mortality. Preeclampsia accounts for at least 200,000 maternal deaths worldwide each year. Preeclampsia is a pregnancy complication characterized by high blood pressure (systolic blood pressure ≥140 mmHg (19 kPa) or diastolic blood pressure ≥90 mmHg (12 kPa)) and signs of damage to other organ systems (most commonly the liver and kidneys). Other signs and symptoms of preeclampsia may include: excessive protein in the urine (proteinuria), severe headache, blurred vision, nausea, decreased urine output and shortness of breath (caused by fluid in the lungs), rapid weight gain and swelling (edema) (especially in the face and hands). Edema is one of the symptoms of a preeclamptic seizure. Edema is an abnormal accumulation of fluid in the interstitium, which causes swelling of the fingers and reduces hand mobility and grip strength.

[0003] In women with normal blood pressure, preeclampsia typically begins after 20 weeks of pregnancy. Diagnosis of preeclampsia is usually performed during routine prenatal checkups. Undiagnosed cases of preeclampsia may occur. Furthermore, high blood pressure may develop slowly or occur suddenly.

[0004] Some women may have been ill for weeks before symptoms appear, while others may develop dangerous levels within days. When pregnant women do not recognize the symptoms, the condition can lead to more serious consequences if left untreated. The more severe the preeclampsia, the greater the risk to both the mother and baby. Therefore, daily recognition and identification of warning signs can provide for timely diagnosis of preeclampsia during pregnancy.

[0005] Preeclampsia is usually diagnosed by healthcare professionals during routine prenatal checkups. Currently, preeclampsia is often diagnosed too late because checkups are not performed frequently enough. Furthermore, preeclampsia is a dynamic condition that develops at different rates in different women. Therefore, preeclampsia often remains unnoticed until the next checkup, or until it becomes more serious, until more severe symptoms (such as seizures) occur. However, increasing the cost of routine checkups is too high and puts a strain on the healthcare system.

[0006] Therefore, there is a need for a solution that can help women detect early signs of preeclampsia and thus seek professional help as early as possible.

[0007] WO 2020 / 006518 discloses a device for measuring blood pressure, for example, from a user's finger. The device includes a touch-sensitive screen. Blood pressure measurement is obtained by detecting pressure applied by the finger and blood volume oscillations from a PPG sensor. Summary of the Invention

[0008] This invention is defined by the claims.

[0009] According to one aspect of the present invention, a system is provided, the system comprising:

[0010] A first sensor is used to generate a swelling signal based on the user pressing the first sensor with a body part;

[0011] A second sensor is used to generate a blood signal related to the blood volume in the body part when the user presses the first sensor;

[0012] A force sensor for measuring the force applied to the first sensor by the body part when the user presses the first sensor; and

[0013] Processor, the processor being configured to:

[0014] When the force sensor measures a first predetermined value, a swelling indication of the body part is determined based on the swelling signal; and

[0015] When the blood signal reaches a second predetermined value, the blood pressure indication at the body part is determined based on the force value measured by the force sensor.

[0016] The system is capable of monitoring blood pressure and swelling using a single sensor device. The processor is also configured to determine an indication of the increased likelihood of preeclampsia based on the indications of swelling and blood pressure.

[0017] The two main symptoms of preeclampsia are high blood pressure and edema (i.e., swelling). It is impossible to diagnose preeclampsia solely based on these two symptoms, but they do indicate that the user should seek medical help. This greatly increases the chances of early diagnosis without unnecessary and expensive medical visits.

[0018] When the blood signal (from the second sensor) reaches a second predetermined value, the blood pressure indication is determined by measuring the force exerted from the user onto the device (using the device's force sensor). For example, the blood signal can indicate the amount of blood volume flowing through a body part. When blood flow reaches zero, it means that the force applied by the user is sufficient to counteract the blood pressure and thus stop blood flow. Therefore, force is a useful indicator of blood pressure when this occurs.

[0019] When the force applied by the user reaches a first predetermined value, a swelling indication is determined by measuring a swelling signal (from a first sensor). The first predetermined value of the force is arbitrary; however, it ensures that the swelling is measured at a known constant force value. For example, the swelling signal could indicate the area of ​​the body part in contact with the first sensor.

[0020] Therefore, the present invention provides a device that is easy to use, low in cost, inconspicuous, and can be integrated into the daily life of pregnant women. For example, screening can be performed while brushing teeth, weighing oneself, using a smartphone, etc. Furthermore, the device does not require two separate procedures for measuring blood pressure and swelling, and only a single action (one press), thus reducing the time and effort required by the user. This reduction in the user's time and effort increases the likelihood of regular use of the device.

[0021] The present invention also provides a device that can be used to provide indications of other pathologies affecting a user's blood pressure and potentially (or potentially not) causing swelling. For example, an indication of low blood pressure and swelling may suggest heart failure, while an indication of normal blood pressure and swelling may suggest a localized pathology (venous thrombosis, lymphedema, etc.). An indication of high / low blood pressure without swelling may also indicate other possible pathologies.

[0022] The first sensor may include a waveguide (e.g., having a first side and a second side), a light source for coupling light into the waveguide (e.g., on the first side), and a photodetector for detecting light coupled from the light source from the waveguide (e.g., on the second side), wherein the swelling signal is based on the light detected by the photodetector. Therefore, in this example, swelling is used to influence the optical path in the optical sensing system.

[0023] Due to the difference in refractive index between body skin and air, the amount of light present in a waveguide varies based on the contact area of ​​the body part with the waveguide. Light is coupled out of the waveguide due to the skin of the body part; therefore, the greater the contact area, the more light is coupled out of the waveguide. A photodetector can then measure how much light is coupled out (before the light reaches the photodetector).

[0024] The first sensor may include an imaging device for imaging a body part when a user presses the imaging device, wherein the swelling signal is based on the image of the body part. Therefore, in this example, image analysis is used to determine the swelling.

[0025] The first sensor may include an electrode array, wherein each electrode is configured to detect whether a body part is in contact with the electrode when the user presses the electrode array, and wherein the swelling signal is based on the electrodes in the electrode array that are in contact with the body part and / or those that are not in contact with the body part. Therefore, in this example, contact analysis (or lack of contact) is used to determine swelling.

[0026] Examples of such electrode arrays include capacitive fingerprint sensors, such as those used in some smartphones / tablets. The swelling signal can indicate the area of ​​the body part in contact with the first sensor. Alternatively, the swelling signal can indicate the pattern of peaks and valleys in the fingerprint (or other skin patterns). The fingerprint pattern will remain constant, but if the finger begins to swell, the distance between the peaks and valleys will change.

[0027] The second sensor can be an optical volumetric plethysmography (PPG) sensor, used to detect changes in blood volume in a body part when the user presses the first sensor.

[0028] A PPG sensor illuminates the skin and measures changes in light absorption. Light absorption varies depending on the volume of blood beneath the skin, thus allowing for the measurement of changes in blood volume. A PPG sensor can be implemented using a pulse oximeter. A PPG sensor can also be configured to measure a user's heart rate.

[0029] The processor can be configured to determine the likelihood of increased preeclampsia based on a swelling indicator higher than a historical swelling indicator and a blood pressure indicator higher than a historical blood pressure indicator. The indication of the likelihood of increased preeclampsia may be based on a swelling indicator higher than a historical swelling indicator or a swelling threshold and a blood pressure indicator higher than a historical blood pressure indicator or a blood pressure threshold.

[0030] The first sensor, the second sensor, the force sensor, and the processor may be part of a handheld or wearable device. Alternatively, the first sensor, the second sensor, and the force sensor may be part of a handheld or wearable device, and the processor may be part of a remote device, wherein the handheld or wearable device includes a first data communication system, and the remote device includes a second data communication system for transmitting data to the first data communication system of the handheld or wearable device.

[0031] The system of the present invention can be used to implement a method, the method comprising:

[0032] The swelling signal is generated based on the user pressing a part of their body against the first sensor.

[0033] When the user presses the first sensor, a blood signal is generated that is related to the blood volume in the body part;

[0034] Measure the force exerted by the body part on the first sensor when the user presses the first sensor;

[0035] When the force sensor measures a first predetermined value, a swelling indication of the body part is determined based on the swelling signal; and

[0036] When the blood signal reaches a second predetermined value, the blood pressure indication at the body part is determined based on the force value measured by the force sensor.

[0037] The method further includes indicators to determine the likelihood of increased preeclampsia based on swelling and blood pressure indicators. These indicators of increased likelihood of preeclampsia are not a diagnosis, but rather an indication that a diagnosis is necessary. Therefore, they are indicators of medical interest, not a diagnosis.

[0038] The signals that generate swelling may include:

[0039] Monitor the light coupled from the waveguide when the body part is pressed against the waveguide; or

[0040] When a user presses the imaging device, it images a part of the body; or

[0041] When a user presses the electrode array, the system senses the contact between the body part and the electrode array.

[0042] The blood signal can be generated based on changes in blood volume in a body part when the user presses the first sensor.

[0043] The likelihood of increased preeclampsia can be based, for example, on a swelling index higher than the historical swelling index and a blood pressure index higher than the historical blood pressure index.

[0044] The present invention also provides a computer program product including computer program code means, which, when executed on a computing device having a processing system, causes the processing system to perform all the steps of the method described above.

[0045] These and other aspects of the invention will become apparent from the embodiments described below. Attached Figure Description

[0046] To better understand the invention and to more clearly illustrate how to implement it, reference will now be made to the accompanying drawings by way of example only, wherein:

[0047] Figure 1 A diagram showing a system utilizing body parts is provided.

[0048] Figure 2 A diagram of a system that utilizes a user's swollen body parts is shown;

[0049] Figure 3 The system shown includes a waveguide, a light source, and a photodetector as its first sensor;

[0050] Figure 4 The system shown includes a waveguide, a light source, and a photodetector as its first sensor, and the body part is a swollen finger.

[0051] Figure 5 This illustrates a system in which the first sensor is a fingerprint sensor;

[0052] Figure 6 The system shown is a fingerprint sensor as the first sensor, and the user has a swollen finger;

[0053] Figure 7 A first example of a system with an opaque first sensor is shown;

[0054] Figure 8 A second example of a system with an opaque first sensor is shown; and

[0055] Figure 9 A flowchart of the data analysis performed by the processor is shown. Detailed Implementation

[0056] The invention will be described with reference to the accompanying drawings.

[0057] It should be understood that while the detailed description and specific examples indicate exemplary embodiments of the apparatus, system, and method, they are for illustrative purposes only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, system, and method of the present invention will become more readily apparent from the following description, the appended claims, and the accompanying drawings. It should be understood that the drawings are merely schematic and not drawn to scale. It should also be understood that the same reference numerals are used in all the drawings to denote the same or similar parts.

[0058] This invention provides a system comprising: a first sensor for generating a swelling signal based on a user pressing the first sensor with a body part; a second sensor for generating a blood signal indicating the blood volume in the body part when the user presses the first sensor; and a force sensor for measuring the force applied to the first sensor by the body part when the user presses the first sensor. The system further includes a processor configured to: determine a swelling indication of the body part based on the swelling signal when the force sensor measures a first predetermined value; and determine a blood pressure indication at the body part based on the force value measured by the force sensor when the blood signal reaches a second predetermined value. The indication of an increased likelihood of preeclampsia can thus be based on the swelling indication and the blood pressure indication.

[0059] The detection of two symptoms, high blood pressure and edema (i.e., swelling), can greatly aid in the early prediction of preeclampsia. The system of this invention is capable of simultaneously assessing changes in blood pressure and swelling in body parts (such as the fingers).

[0060] Figure 1A diagram of a system 100 utilizing a user's body part 108 is shown, in this example, specifically a finger. Figure 2 A diagram shows a system 100 that utilizes a user's swollen body part 108a. The processor of the system 100 is... Figure 1 or Figure 2 Not shown in the image.

[0061] The first sensor 102 and the force sensor 106 are used to determine an indication of swelling at body part 108. The system 100 also includes a second sensor 104, which, in conjunction with the force sensor 106, provides an indirect measurement of blood pressure (i.e., an indication of blood pressure).

[0062] It is known that when pressure is applied to the skin, the skin becomes less red. This is because pressure removes perfused blood from the area beneath the surface. Therefore, if an indication of blood volume is measured, the indication will decrease as blood is forced out. For example, in optical heart rate monitoring, optical plethysmography (PPG) will show a disappearance of the PPG signal as blood is forced out.

[0063] The force required for the PPG signal to disappear is proportional to the blood pressure in body part 108. Clearly, the force applied to the skin needs to overcome blood pressure to remove blood, therefore higher pressure is required to remove blood in people with higher blood pressure.

[0064] The second sensor 104 is configured to generate a blood signal that indicates the volume of blood in a specific body part 108. The blood signal represents the blood volume. The second sensor may be, for example, a PPG sensor, such that the blood signal is a PPG signal. Alternatively, the second sensor 104 may include an optical sensor for measuring the color of the skin on the body part 108 to derive the blood signal. The skin color seen from the outside will change according to the volume of blood in the body part.

[0065] When the pressure is at a known force, when body part 108 is pushed against the first sensor 102, the first sensor 102 estimates the area of ​​body part 108. Figure 1 and Figure 2 The principle behind determining the degree of swelling of body part 108 (in this case, the fingers) can be seen in the middle.

[0066] Figure 2 It shows relative to Figure 1 Swollen finger 108a. For Figure 2 The swollen finger 108a in the middle, the contact area between the swollen finger 108a and the first sensor 102 is greater than Figure 1 The contact area between the non-swollen finger 108 and the first sensor 102.

[0067] If finger 108 is not swollen ( Figure 1 If the area of ​​finger 108 under force F1 is given by area A1, then the area of ​​finger 108 is given by area A1. However, if finger 108a swells ( Figure 2 The same force F1 will produce a larger contact area A2 on the first sensor 102. Therefore, the degree of swelling can be obtained by increasing the contact area under a given contact force.

[0068] In this example and in future examples, finger 108 is shown to illustrate and describe the invention. However, finger 108 is not the only body part that can be used on system 100. The invention requires indications of blood pressure and swelling that can be obtained from any body part 108 of the user (e.g., toes), and system 100 can be designed / manufactured for different body parts 108.

[0069] Figure 3 The system 100 is shown, wherein the first sensor 102 includes a waveguide 302, a light source 304, and a photodetector 306. Figure 4 The system 100 is shown, wherein the first sensor 102 includes a waveguide 302, a light source 304, and a photodetector 306, and wherein the body part is a swollen finger 108a. The processor is not in... Figure 3 As shown in 4.

[0070] In this example, the first sensor has a waveguide 302, a light source 304, and a photodetector 306 (i.e., a photodetector) to measure the area of ​​the finger 108 in contact with the waveguide 302 under a given pressure. On one side of the waveguide 302, the light source 304 (e.g., an LED) is configured to inject light into the waveguide 302. On the other side of the waveguide 302, a photodetector 306 (e.g., a photodiode) is attached and measures the light emitted from the waveguide 302.

[0071] When finger 108 is pressed against waveguide 302, a certain amount of light will couple out of waveguide 302 because finger 108 has a higher refractive index than air. As a result, the amount of light reaching photodetector 306 will decrease. The larger the contact area, the more light will couple out of waveguide 302, and therefore the signal from photodetector 306 will decrease accordingly.

[0072] In this example, the light source 304 and the photodetector 306 are depicted opposite each other. However, this is not necessary, because the photodetector 306 can measure the light present in the waveguide 302 at any point on the waveguide 302.

[0073] Figure 4 This shows that, compared to the non-swollen finger 108, the swollen finger 108a creates a larger contact area with the waveguide 302 (e.g., Figure 3 (As shown). In Figure 3 and Figure 4In the middle, waveguide 302 is transparent and located above the second sensor 104.

[0074] In the following description, it is assumed that the second sensor 104 is a PPG sensor.

[0075] The system 100 with waveguide 302 operates as follows:

[0076] (i) The user presses his finger 108 on the top of the waveguide 302.

[0077] (ii) As the user increases the force, the PPG signal from the PPG sensor 104 begins to decrease.

[0078] (iii) Simultaneously, the area of ​​the finger 108 in contact with the waveguide 302 increases as the tip of the finger 108 flattens. As a result, the signal from the photodetector 306 begins to decrease.

[0079] (iv) Under a specified reference force, record the signal of photodetector 306 (the signal is an indication of swelling of finger 108).

[0080] (v) The user continues to press waveguide 302 with greater force.

[0081] (vi) Under a certain force, blood diffuses out of the volume of the finger 108 that can be detected by the PPG sensor 104. At this time, the PPG signal disappears (becomes zero). The force measured by the force sensor 106 when the PPG signal disappears is an indication of the user's blood pressure.

[0082] (vii) Optionally, after capturing two measurement results, the system may instruct the user to remove finger 108 from waveguide 302.

[0083] In this way, a quick and easy (for the user) method allows the user to quantify the indications of swelling and blood pressure in a simple process (i.e., pressing the body part 108 onto the first sensor 102 with (steadily) increasing force).

[0084] In most cases, any changes in swelling and / or blood pressure are tracked to identify any indications / risks or preeclampsia. However, in some cases, knowing the actual blood pressure or degree of swelling can be advantageous. This can be achieved using algorithms, lookup tables, or similar conversion methods that translate measurements into the actual blood pressure or degree of swelling.

[0085] Figure 5 The system 100 is shown, in which the first sensor 102 is a fingerprint sensor. Figure 6 The system 100 is shown, wherein the first sensor 102 is a fingerprint sensor, and wherein the user has a swollen finger 108a. The processor is not in... Figure 5 or Figure 6 As shown in the image.

[0086] Various types of fingerprint sensors 102 exist (e.g., photoelectric forms). Optical forms use (CCD) pixel arrays or other photosensitive devices (e.g., photodiodes) and optionally some simple imaging optics (e.g., microlens arrays). In the simplest form, the measurement is a contact measurement. In other variations, an image of the fingerprint is projected onto an array of optical sensors via imaging optics.

[0087] In one example, the fingerprint sensor 102 is an imaging device, such as one used for securing and unlocking mobile devices. Therefore, the system 100 will monitor the blood pressure and swelling of the finger 108 (or toe). However, the imaging device 102 can be used anywhere on the body, where characteristic patterns 502 on the skin (e.g., ridges, blemishes, hair, sweat glands, etc.) can be identified. This is because the characteristic patterns 502 of the body part 108 will swell as the body part 108 swells. In this example, only the form of the fingerprint will be discussed further.

[0088] The essence of the operation is to determine the distance between the ridges and grooves in the fingerprint pattern 502 when the finger 108 is pressed onto the imaging device 102 with a given pressure. An increase in the distance between the characteristic features (i.e., the ridges and grooves of the fingerprint 502) indicates that the finger 108a is swollen.

[0089] Another advantage of using the fingerprint sensor 102 is that the fingerprint 502 (or actually any feature pattern of the body) automatically identifies the user of the system 100, thus ensuring that the measurement result is automatically attributed to the correct user.

[0090] Alternatively, the fingerprint sensor 102 can be a capacitive fingerprint sensor. This typically involves an array of electrodes forming a capacitor with the finger 108. The measurement is a contact measurement (i.e., the user places their finger 108 on the fingerprint sensor 102). Fingerprints 502 are detected as the ridges of the fingerprint 502 form a higher capacitance with the array as they get closer to it, while the grooves form a lower capacitance.

[0091] The fingerprint sensors 102 (i.e., optical or electrical) can be formed such that they are (partially) transparent, for example, by creating an array on a glass substrate and using the same techniques as those used for substrates used in flat panel displays (transistors of amorphous Si or polycrystalline Si). Alternatively, such an array can be formed on an opaque substrate such as a Si wafer.

[0092] Depending on whether the substrate is transparent or opaque, different variations of the device that have a first sensor 102 can be implemented as a fingerprint sensor. The case of a transparent fingerprint sensor device is as follows... Figure 5 and6 The image shows the sensor positioned above the PPG sensor 104. This configuration is also configured to allow for the measurement of contact force (in this case, by supporting the fingerprint sensor 102 and the PPG sensor 104 on the force sensor 106).

[0093] The system 100 with fingerprint sensor 102 operates as follows:

[0094] (i) The user presses his finger 108 on the top of the fingerprint sensor 102.

[0095] (ii) When the user increases the force, the PPG signal begins to decrease.

[0096] (iii) At the same time, the area of ​​the finger 108 in contact with the fingerprint sensor 102 increases as the tip of the finger 108 flattens.

[0097] (iv) The fingerprint sensor 102 begins to measure the fingerprint pattern 502.

[0098] (v) Under a specified reference force, record fingerprint pattern 502. The signal containing the pattern (and the distance between the ridges and grooves) is an indication of finger swelling.

[0099] (vi) The user continues to press the fingerprint sensor 102 with greater force.

[0100] (vii) Under a certain force, blood diffuses out of the volume of the finger 108 that can be detected by the PPG sensor 104. At this time, the PPG signal disappears. Therefore, this force is an indication of the user's blood pressure.

[0101] (viii) Optionally, after capturing two measurements, the system 100 may instruct the user to remove their finger 108.

[0102] Figure 7 A first example of a system 100 with an opaque first sensor 102 is shown. Figure 8 A second example of a system with an opaque first sensor 102 is shown. The processor is not in... Figure 7 or Figure 8 As shown in the image.

[0103] When the first sensor 102 is non-transparent, the arrangement of the first sensor 102 and the second sensor 104 is different. Figure 7 and Figure 8 Two variations of this arrangement can be seen. Because the first sensor 102 is opaque, it must be positioned adjacent to the second sensor 104. Figure 7In this configuration, the second sensor 104 is arranged side by side with the first sensor 102. This has the advantage that the first sensor 102 and the second sensor 104 can remain unchanged in the system 100.

[0104] exist Figure 8 In this configuration, the second sensor 104 is located at the center of the first sensor 102. An opening must be made in the first sensor 102. This configuration has the advantage of a small form factor (i.e., it may have the same form factor as existing fingerprint sensors in smartphones and tablet PCs).

[0105] For example, the first sensor 102 may be a non-transparent fingerprint sensor used to determine the feature pattern 502 of the body part 108.

[0106] These two arrangements of the sensor are configured to allow contact force to be measured by supporting the structure on the force sensor 106.

[0107] Instead of force, force sensor 106 can measure pressure. Therefore, force can be determined from the area where the first sensor 102 and / or the second sensor 104 are in contact with force sensor 106.

[0108] The operation of the opaque first sensor 102 is the same as that of the transparent first sensor 102.

[0109] The system is suitable for integration into consumer devices, specifically handheld devices, and more specifically smartphones, tablets, handheld computers, and laptop mice. In such devices, the system can be integrated into the surface, such as (smart) buttons or fingerprint sensors. However, it can also be integrated into other consumer devices, such as toothbrushes, shavers, and epilators.

[0110] Figure 9 A flowchart illustrating the data analysis performed by processor 902 is shown. Processor 902 determines a swelling indicator 912 and a blood pressure indicator based on signals generated by first sensor 102, second sensor 104, and force sensor 106. Then, processor 916 determines an indication 916 indicating an increased likelihood of preeclampsia for the user based on the swelling indicator 912 and blood pressure indicator 914.

[0111] A swelling signal 904 is generated by the first sensor 102 based on the force applied to the first sensor 102 by the user using body part 108. When the user applies force to the first sensor 102, the second sensor 104 generates a blood signal based on the blood volume in body part 108. The force applied to the first sensor 102 by the body part 108 is also measured by the force sensor 106.

[0112] When force sensor 106 measures a force of a first predetermined value 906, processor 902 determines a swelling indication 912 of body part 108 based on swelling signal 904. The first predetermined value 906 of force will vary significantly based on differences between users. This value 906 can be determined by calibrating the device upon first use (i.e., requiring the user to press the first sensor 102 with "normal force"). Alternatively, the first predetermined value can be a fixed value (e.g., 2N).

[0113] Additionally, when the blood signal reaches a second predetermined value 910, the processor 902 determines an indication of blood pressure 914 at body part 108 based on the force value 908 measured by the force sensor 106. For example, if the second sensor 104 is a PPG sensor, the second predetermined value 910 could be when the PPG signal reaches zero (or is close to zero). Alternatively, the second sensor 104 could observe the color of the skin in contact with the first sensor 102, and the second predetermined value 910 could be a certain color (i.e., less red in the skin color due to reduced blood volume).

[0114] The blood volume in a user's body part can be estimated by measuring the time it takes for the blood signal to reach a second predetermined value 910.

[0115] Therefore, an indication 9126 indicating an increased likelihood of preeclampsia can be determined based on the swelling indication 912 and the blood pressure indication 914. For example, both the swelling indication 912 and the blood pressure indication 914 may be above their respective thresholds. Alternatively, the swelling indication 912 and / or the blood pressure indication 914 may have increased (compared to historical values).

[0116] The above examples demonstrate the particular advantage of obtaining measurements of edema and blood pressure for detecting the risk of preeclampsia. However, the sensor system of the present invention can be used in any situation where the assessment of edema and blood pressure is of interest to a particular user.

[0117] For example, a low blood pressure and swelling indication may indicate the possibility of heart failure in a user; a normal blood pressure and swelling indication may indicate the possibility of a local pathology (thrombosis, lymphedema, etc.); or a high / low blood pressure and no swelling indication may indicate other pathologies. The processor 902 may include an algorithm for distinguishing different pathological indications based on blood pressure and swelling indications.

[0118] As described above, the device utilizes a processor to perform data processing. The processor can be implemented in various ways, using software and / or hardware, to perform a variety of required functions. The processor typically employs one or more microprocessors that can be programmed using software (e.g., microcode) to perform the desired functions. The processor can be implemented as a combination of dedicated hardware performing certain functions and one or more programmable microprocessors and associated circuitry performing other functions. Those skilled in the art can readily develop processors for performing any of the methods described herein.

[0119] Examples of circuits that may be used in various embodiments of the present invention include (but are not limited to) conventional microprocessors, application-specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).

[0120] In various implementations, the processor may be associated with one or more storage media, such as volatile and non-volatile computer memories (e.g., RAM, PROM, EPROM, and EEPROM). The storage media may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform the required functions. The various storage media may be fixed within the processor or controller, or may be transferable, such that one or more programs stored thereon can be loaded into the processor. A single processor or other unit may implement the functions described in the claims.

[0121] By studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments in practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0122] The fact that certain measures are described in mutually different dependent claims does not imply that combinations of these measures cannot be used advantageously.

[0123] Computer programs can be stored / distributed on suitable media, such as optical or solid-state media provided with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

[0124] If the term “suitable” is used in the claims or specification, it should be noted that the term “suitable” is intended to be equivalent to the term “configured as”.

[0125] Any reference numerals in the claims should not be construed as limiting the scope.

Claims

1. A system (100) for determining the probability of increased preeclampsia, comprising: A first sensor (102) is used to generate a swelling signal (904) based on the user pressing the first sensor (102) with a body part (108). The second sensor (104) is used to generate a blood signal related to the blood volume in the body part (108) when the user presses the first sensor (102); A force sensor (106) is used to measure the force applied to the first sensor (102) by the body part (108) when the user presses the first sensor; as well as The processor (902) is configured to: When the force sensor (106) measures a first predetermined value (906), a swelling indication (912) of the body part (108) is determined based on the swelling signal (904). When the blood signal reaches a second predetermined value (910), a blood pressure indication (914) at the body part (108) is determined based on the force value (908) measured by the force sensor (106); and The likelihood of increased preeclampsia is determined based on the swelling indication and the blood pressure indication (916).

2. The system (100) according to claim 1, wherein the first sensor (102) comprises: Waveguide (302); A light source (304) is used to transmit light into the waveguide (302); as well as A photodetector (306) is used to detect light coupled from the light source (304) from the waveguide. The swelling signal (904) is based on light detected by the photodetector (306).

3. The system (100) according to claim 1, wherein the first sensor (102) comprises: An imaging device for imaging the body part (108) when the user presses the imaging device, wherein the swelling signal (904) is based on the image of the body part (108).

4. The system (100) of claim 1, wherein the first sensor (102) comprises an electrode array, and wherein each electrode is configured to detect whether the body part (108) is in contact with the electrode when the user presses the electrode array, wherein the swelling signal (904) is based on the electrodes in the electrode array that are in contact with the body part (108) and / or the electrodes in the electrode array that are not in contact with the body part (108).

5. The system (100) according to any one of claims 1 to 4, wherein the second sensor (104) is an optical volumetric plethysmography (PPG) sensor for detecting changes in blood volume in the body part when the user presses the first sensor (102).

6. The system (100) according to any one of claims 1 to 4, wherein the first sensor (102) is a fingerprint sensor.

7. The system (100) according to any one of claims 1 to 4, wherein: The first sensor (102), the second sensor (104), the force sensor (106), and the processor (902) are part of a handheld or wearable device; or The first sensor (102), the second sensor (104), and the force sensor (106) are part of a handheld or wearable device, and the processor (902) is part of a remote device, wherein the handheld or wearable device includes a first data communication system, and the remote device includes a second data communication system for data communication with the first data communication system of the handheld or wearable device.

8. The system (100) according to any one of claims 1 to 4, wherein the processor (902) is configured to determine (916) an indication of the likelihood of increased preeclampsia based on: The swelling indicator (912) is higher than the historical swelling indicator or the swelling threshold; and The blood pressure indication (914) is higher than the historical blood pressure indication or blood pressure threshold.

9. A computer program product comprising computer program code means, adapted to perform a method when executed on a processor of a system according to any one of claims 1 to 8, the method comprising: A swelling signal (904) is generated based on the user pressing the first sensor (102) with a body part (108); When the user presses the first sensor (102), a blood signal is generated that is related to the blood volume in the body part (108); When the user presses the first sensor (102), the force applied to the first sensor (102) by the body part (108) is measured; When the force sensor (106) measures a first predetermined value (906), a swelling indication (912) of the body part (108) is determined based on the swelling signal (904). When the blood signal reaches a second predetermined value (910), a blood pressure indication (914) at the body part (108) is determined based on the force value (908) measured by the force sensor (106); and The likelihood of increased preeclampsia was determined from the swelling indication and the blood pressure indication (916).

10. The computer program product of claim 9, wherein generating the swelling signal (904) comprises: Monitor the light coupled from the waveguide (302) when the body part (108) is pressed against the waveguide (302); or When the user presses the imaging device, the body part (108) is imaged; or When the user presses the electrode array, the contact between the body part and the electrode array is sensed.

11. The computer program product of claim 9, wherein generating the blood signal comprises: When the user presses the first sensor (102), the change in blood volume in the body part is detected.

12. The computer program product of claim 10, wherein generating the blood signal comprises: When the user presses the first sensor (102), the change in blood volume in the body part is detected.

13. The computer program product according to any one of claims 9 to 12, wherein determining the probability of increased preeclampsia (916) is based on: The swelling indicator (912) is higher than the historical swelling indicator or swelling threshold; and The blood pressure indication (914) is higher than the historical blood pressure indication or blood pressure threshold.

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