METHOD AND APPARATUS FOR EDEMA DETECTION

A system has an electronic interface, one or more sensors, a memory, and a control system including one or more processors. The processors are configured to execute instructions for activating an edema test, automatically or in response to receiving a user request via the electronic interface. Upon activation, user instructions are provided to locate, via one or more of the sensors, a skin area in the subject for testing. A user is instructed to depress the skin area for causing a temporary indentation. One or more images of the temporary indentation are captured, via one or more of the sensors, over a period of time following the depression of the skin area by the user. The images are analyzed for characteristics of skin bounce-back, which represents rebounding of the skin area after the temporary indentation. An edema result is determined based on the characteristics of the skin bounce-back.

TECHNICAL FIELD

The present disclosure relates generally to systems and methods for edema testing, and more particularly, to systems and methods for analyzing characteristics of skin bounce-back in a subject to provide an edema result.

BACKGROUND

Edema shows observable swelling from fluid accumulation in body tissues of a person. Most commonly, edema occurs in feet, ankles, legs, and/or hands. The swelling is the result of the accumulation of excess fluid under the skin in the spaces within the tissues. According to one example, a pitting edema is demonstrated by applying pressure to a swollen area by depressing the skin with a finger. In fact, any form of pressure, such as from the elastic in socks, can induce pitting with this type of edema. Thus, symptoms of the pitting edema include swelling, which causes the skin surrounding it to tighten. The skin over the swollen area typically appears shiny and light, and, often, when a finger is placed on the swollen area an indentation is left on the skin.

Pitting edema is often diagnosed with a physical exam. For example, a doctor may apply pressure to the swollen skin for about 15 seconds to check for an indentation. After pressing the affected body part with a finger, the edema is classified based on the depth and duration of the indentation. The test provides, for example, a grade that ranges from Grade 1 to Grade 4. Grade 1 is associated with a pressure that typically leaves an indentation of 0-2 millimeters (“mm”) and rebounds generally immediately. This is the least severe type of pitting edema. Grade 2 is associated with a pressure that typically leaves an indentation of 3-4 mm and rebounds in fewer than 15 seconds. Grade 3 is associated with a pressure that typically leaves an indentation of 5-6 mm and takes up to 30 seconds to rebound. Grade 4 is associated with a pressure that typically leaves an indentation of 8 mm or deeper and takes more than 20 seconds to rebound.

Understanding the severity of edema is helpful in identifying the underlying cause and the best course of treatment. However, present testing methods are plagued by many problems. For example, some present testing methods are non-user friendly, relying mostly on those with vast medical experience (e.g., doctors) to accurately administer the test. Consequently, typical patients cannot properly and accurately administer self-tests, as they lack the proper knowledge of where to apply the pressure, how long to apply the pressure, and how deep to apply the pressure. In another example, some present testing methods lack consistency. Testing the wrong body part may result in inaccurate test results, leading the patient into the wrong treatment or, worse, into no treatment at all.

The present disclosure is directed to solving these and other problems, including problems associated with present edema testing.

SUMMARY

According to some implementations of the present disclosure, a system includes an electronic interface that is configured to receive user input and to provide user instructions. The user input includes a user request for an edema test, and the user instructions include procedural steps for the edema test. The system further includes one or more sensors for detecting a change in skin characteristics of a subject, and a memory storing machine-readable instructions. The system further includes a control system having one or more processors configured to execute the machine-readable instructions. The instructions include the activation of the edema test automatically or in response to receiving the user request via the electronic interface. Upon activation, providing the user instructions for locating, via at least one of the one or more sensors, a skin area in the subject for testing. The instructions further include instructing a user to depress the skin area for causing a temporary indentation, and capturing, via at least one of the one or more sensors, one or more images of the temporary indentation over a period of time following the depression of the skin area by the user. The instructions also include analyzing the one or more images for characteristics of skin bounce-back, the skin bounce-back representing rebounding of the skin area after the temporary indentation. The instructions also include determining an edema result based on the characteristics of the skin bounce-back.

According to some other implementations of the present disclosure, a method includes activating an edema test via an electronic device, in response to receiving a user request. Upon activating the edema test, the method further includes locating for a user a skin area of a subject for testing of edema. In response to locating the skin area, the user is instructed to depress the skin area for causing a temporary indentation. One or more images of the temporary indentation are captured during an elapsed time period in which the skin area bounces back to a full or partial undepressed state. The one or more images are analyzed for characteristics of skin bounce-back. An edema result is determined based on the characteristics of the skin bounce-back.

According to yet other implementations of the present disclosure, a system is directed to determining an edema result. The system includes a probe having a proximal end and a distal end. The distal end has a distal surface for causing a temporary indentation in a skin surface of a subject. The system further includes an electronic device with a housing for enclosing internal components. The housing has an external surface on which the proximal end of the probe is removably attached. The electronic device further has an electronic interface configured to receive user input from a user and to provide user instructions. The user input includes a user request for an edema test. The user instructions include procedural steps for the edema test. The electronic device also has a camera for detecting a change in skin characteristics of the subject, and a memory storing machine-readable instructions. The electronic device also has a control system including one or more processors configured to execute the machine-readable instructions. The machine-readable instructions include to activate the edema test in response to receiving the user request via the electronic interface. Upon activation of the edema test, the user instructions are provided for locating via the camera the skin area in the subject for testing. The user is instructed to depress the skin area for causing the temporary indentation. One or more images of the temporary indentation are captured, via the camera, as the skin area bounces back to a full or partial undepressed state. The images are analyzed for characteristics of skin bounce-back. An edema result is determined based on the characteristics of the skin bounce-back.

DETAILED DESCRIPTION

Elements and limitations that are disclosed, for example, in the Abstract, Summary, and Detailed Description sections, but not explicitly set forth in the claims, should not be incorporated into the claims, singly, or collectively, by implication, inference, or otherwise. For purposes of the present detailed description, unless specifically disclaimed, the singular includes the plural and vice versa. The word “including” means “including without limitation.” Moreover, words of approximation, such as “about,” “almost,” “substantially,” “approximately,” “generally,” and the like, can be used herein to mean “at,” “near,” or “nearly at,” or “within 3-5% of,” or “within acceptable manufacturing tolerances,” or any logical combination thereof, for example.

Generally, the present disclosure describes a method and system for detecting edema in a patient (also referred to herein as a subject), based on analyzing bounce-back (or rebounding) of skin when depressed. The bounce-back is analyzed, for example, to determine how long it takes for the depressed skin to fully or partially rebound. The bounce-back is optionally analyzed by determining a color change of the affected skin area over time. For example, a color change is used to provide additional information related to skin characteristics during the bounce-back. The additional information includes, for example, where an indentation has occurred, blood flow at an indentation site, edema fluid flow at the indentation site, etc. Optionally, the system includes a probe that attached to an electronic device, such as a mobile device, to aid in applying pressure to the skin in a repeatable manner. The probe further allows a camera to view the test area through a lens or window of the probe 100% of the time while performing the edema test.

Referring toFIG.1, a system100, according to some implementations of the present disclosure, is illustrated. The system100includes a control system110, a memory device114, an electronic interface119, one or more sensors130, and one or more user devices170. According to one exemplary implementation, discussed in more detail below, the system100includes a user mobile device, such as a mobile phone. The user device170, such as the mobile phone, optionally includes in one exemplary implementation the control system110, the memory device114, the electronic interface119, and at least one sensor130, as further described in more detail below.

The control system110includes one or more processors112(hereinafter, processor112). The control system110is generally used to control (e.g., actuate) the various components of the system100and/or analyze data obtained and/or generated by the components of the system100. The processor112can be a general or special purpose processor or microprocessor. While one processor112is shown inFIG.1, the control system110can include any suitable number of processors (e.g., one processor, two processors, five processors, ten processors, etc.) that can be in a single housing, or located remotely from each other. The control system110can be coupled to and/or positioned within, for example, a housing of the user device170, and/or within a housing of one or more of the sensors130. The control system110can be centralized (within one such housing) or decentralized (within two or more of such housings, which are physically distinct). In such implementations including two or more housings containing the control system110, such housings can be located proximately and/or remotely from each other.

The memory device114stores machine-readable instructions that are executable by the processor112of the control system110. The memory device114can be any suitable computer readable storage device or media, such as, for example, a random or serial access memory device, a hard drive, a solid state drive, a flash memory device, etc. While one memory device114is shown inFIG.1, the system100can include any suitable number of memory devices114(e.g., one memory device, two memory devices, five memory devices, ten memory devices, etc.). The memory device114can be coupled to and/or positioned within a housing of the user device170, within a housing of one or more of the sensors130, or any combination thereof. Like the control system110, the memory device114can be centralized (within one such housing) or decentralized (within two or more of such housings, which are physically distinct).

The electronic interface119is configured to receive data (e.g., physiological data) from the one or more sensors130such that the data can be stored in the memory device114and/or analyzed by the processor112of the control system110. The electronic interface119can communicate with the one or more sensors130using a wired connection or a wireless connection (e.g., using an RF communication protocol, a WiFi communication protocol, a Bluetooth communication protocol, over a cellular network, etc.). The electronic interface119can include an antenna, a receiver (e.g., an RF receiver), a transmitter (e.g., an RF transmitter), a transceiver, or any combination thereof. The electronic interface119can also include one more processors and/or one more memory devices that are the same as, or similar to, the processor112and the memory device114described herein. In some implementations, the electronic interface119is coupled to or integrated in the user device170. In other implementations, the electronic interface119is coupled to or integrated (e.g., in a housing) with the control system110and/or the memory device114.

The one or more sensors130of the system100include a microphone140, a speaker142, a radio-frequency (RF) receiver146, a RF transmitter148, a camera150, an infrared sensor152, a photoplethysmogram (PPG) sensor154, an electrocardiogram (ECG) sensor156, an electroencephalography (EEG) sensor158, a capacitive sensor160, a force sensor162, a strain gauge sensor164, an electromyography (EMG) sensor166, an oxygen sensor168, a depth sensor169, a sonar sensor171, or any combination thereof. Generally, each of the one or more sensors130is configured to output sensor data that is received and stored in the memory device114or one or more other memory devices.

While the one or more sensors130are shown and described as including each of the microphone140, the speaker142, the RF receiver146, the RF transmitter148, the camera150, the infrared sensor152, the photoplethysmogram (PPG) sensor154, the electrocardiogram (ECG) sensor156, the electroencephalography (EEG) sensor158, the capacitive sensor160, the force sensor162, the strain gauge sensor164, the electromyography (EMG) sensor166, the oxygen sensor168, a depth sensor169, and a sonar sensor171, the one or more sensors130can include any combination and any number of each of the sensors described and/or shown herein. The physiological data generated by one or more of the sensors130can be used by the control system110to determine an edema result based on characteristics of skin bounce-back, as described in more detail below.

The microphone140outputs sound data that can be stored in the memory device114and/or analyzed by the processor112of the control system110. For example, the microphone140can be used to record sound during an edema test session. The microphone140can be coupled to or integrated in the user device170.

The speaker142outputs sound waves that are audible to a user of the system100. The speaker142can be used, for example, as an alarm clock or to play an alert or message to the user (e.g., in response to an event). The speaker142can be coupled to or integrated in the external device170.

The microphone140and the speaker142can be used as separate devices. In some implementations, the microphone140and the speaker142can be combined into an acoustic sensor141(e.g., a sonar sensor), as described in, for example, International (PCT) Patent Publication Nos. WO 2018/050913 and WO 2020/104465, each of which is hereby incorporated by reference herein in its entirety. In such implementations, the speaker142generates or emits sound waves at a predetermined interval and the microphone140detects the reflections of the emitted sound waves from the speaker142. The sound waves generated or emitted by the speaker142have a frequency that is not audible to the human ear (e.g., below 20 Hz or above around 18 kHz). Based at least in part on the data from the microphone140and/or the speaker142, the control system110can determine a location of the subject or subject's body part to be tested, and/or one or more characteristics of the skin bounce-back that is described in more detail below. Optionally or alternatively, the control system110determines a distance to a body part of the subject, mapping of the indentation, and/or respiration of the subject. According to another exemplary implementation, the control system110determines a velocity through a Doppler shift, which allows the control system110to know if the system100is not being held still by the subject or the user. Alternatively, the velocity is determined using an accelerometer. Optionally, if a determination is made that the system100is not being held still, a notification is provided to request that the subject or the user should “hold the device still.” In addition or alternatively, the control system110can determine sleep-related parameters described in herein such as, for example, a respiration signal, a respiration rate, an inspiration amplitude, an expiration amplitude, an inspiration-expiration ratio, a number of events (e.g., snoring, an apnea, a hypopnea, a restless leg, a sleeping disorder, choking, an increased heart rate, labored breathing, an asthma attack, an epileptic episode, a seizure, or any combination thereof) per hour, a pattern of events, a sleep state, a sleep stage, pressure settings of the respiratory device122, or any combination thereof. In this context, a sonar sensor may be understood to concern an active acoustic sensing, such as by generating/transmitting ultrasound or low frequency ultrasound sensing signals (e.g., in a frequency range of about 17-23 kHz, 18-22 kHz, or 17-18 kHz, for example), through the air. Such a system may be considered in relation to WO 2018/050913 and WO 2020/104465 mentioned above. Methods for determining sleep states and/or sleep stages from physiological data generated by one or more of the sensors, such as sensors130, are described in, for example, WO 2014/047310, US 2014/0088373, WO 2017/132726, WO 2019/122413, and WO 2019/122414, each of which is hereby incorporated by reference herein in its entirety.

The RF transmitter148generates and/or emits radio waves having a predetermined frequency and/or a predetermined amplitude (e.g., within a high frequency band, within a low frequency band, long wave signals, short wave signals, etc.). The RF receiver146detects the reflections of the radio waves emitted from the RF transmitter148, and these data can be analyzed by the control system110to determine a location of the subject or the subject's body part to be tested, and/or one or more of the skin bounce-back characteristics described herein, the distance to the body part of a subject, mapping of the indentation, respiration of the subject, and/or the velocity of the system100. An RF receiver (either the RF receiver146and the RF transmitter148or another RF pair) can also be used for wireless communication between the control system110, the one or more sensors130, the user device170, or any combination thereof. While the RF receiver146and RF transmitter148are shown as being separate and distinct elements inFIG.1, in some implementations, the RF receiver146and RF transmitter148are combined as a part of an RF sensor147(e.g., a radar sensor). In such implementations, the RF sensor147includes a control circuit. The specific format of the RF communication could be WiFi, Bluetooth, etc.

In some implementations, the RF sensor147is a part of a mesh system. One example of a mesh system is a WiFi mesh system, which can include mesh nodes, mesh router(s), and mesh gateway(s), each of which can be mobile/movable or fixed. In such implementations, the WiFi mesh system includes a WiFi router and/or a WiFi controller and one or more satellites (e.g., access points), each of which include an RF sensor that the is the same as, or similar to, the RF sensor147. The WiFi router and satellites continuously communicate with one another using WiFi signals. The WiFi mesh system can be used to generate motion data based on changes in the WiFi signals (e.g., differences in received signal strength) between the router and the satellite(s) due to an object or person moving partially obstructing the signals. The motion data can be indicative of motion, breathing, heart rate, gait, falls, behavior, etc., or any combination thereof.

The camera150outputs image data reproducible as one or more images (e.g., still images, video images, thermal images, or a combination thereof) that can be stored in the memory device114. The image data from the camera150can be used by the control system110to determine one or more of the skin bounce-back characteristics.

The infrared (IR) sensor152outputs infrared image data reproducible as one or more infrared images (e.g., still images, video images, or both) that can be stored in the memory device114. The IR sensor152can be used in conjunction with the camera150when measuring the presence, location, and/or movement of a depressed skin area described herein. The IR sensor152can detect infrared light having a wavelength between about 700 nm and about 1 mm, for example, while the camera150can detect visible light having a wavelength between about 380 nm and about 740 nm.

The PPG sensor154outputs physiological data associated with the user that can be used to determine one or more user characteristics, such as, for example, a heart rate, a heart rate variability, a cardiac cycle, respiration rate, an inspiration amplitude, an expiration amplitude, an inspiration-expiration ratio, estimated blood pressure parameter(s), or any combination thereof. According to an exemplary embodiment, the PPG sensor154is part of the mobile phone, such as being part of a camera. According to another exemplary embodiment, the PPG sensor154is part of the camera and the flash of the mobile phone. The PPG sensor154detects a change in intensity of wavelengths, e.g., red, infrared, or green (which are the most common wavelengths). The detected change in wavelength intensity is provided as data for determining an edema result. The PPG sensor154can alternatively or additionally be worn by the user, can be embedded in clothing and/or fabric that is worn by the user, can be embedded in and/or coupled to its associated headgear (e.g., straps, etc.), etc. The physiological data of the PPG sensor154is optionally used to measure a perfusion index, which is correlated with an analysis of one or more images for confirming an edema result (disclosed in more detail below).

The ECG sensor156outputs physiological data associated with electrical activity of the heart of the user. According to exemplary embodiments, the ECG sensor156is worn by the user (e.g., in a smart watch), is embedded in clothing and/or fabric that is worn by the user, is embedded in and/or coupled to its associated chest band (e.g., straps, etc.), etc. The EEG sensor158outputs physiological data associated with electrical activity of the brain of the user. According to exemplary embodiments, the EEG sensor158is worn by the user, is embedded in clothing and/or fabric that is worn by the user, is embedded in and/or coupled to its associated headgear (e.g., straps, etc.), etc.

The capacitive sensor160, the force sensor162, and the strain gauge sensor164output data that can be stored in the memory device114and used by the control system110to determine one or more of the skin bounce-back characteristics described herein. The EMG sensor166outputs physiological data associated with electrical activity produced by one or more muscles. The oxygen sensor168outputs oxygen data indicative of an oxygen concentration of blood. The oxygen sensor168can be, for example, an ultrasonic oxygen sensor, an electrical oxygen sensor, a chemical oxygen sensor, an optical oxygen sensor (such as a PPG sensor), or any combination thereof. In some implementations, the one or more sensors130also include a galvanic skin response (GSR) sensor, a blood flow sensor, a respiration sensor, a pulse sensor, a sphygmomanometer sensor, an oximetry sensor, or any combination thereof.

The depth sensor169detects a distance between the sensor and a patient or user, or a number of distances (or depths) to provide a three-dimensional (3D) representation of the skin area in which the temporary indentation is formed. For example, in reference to testing for edema (as disclosed in more detail below), the depth sensor169detects a change in depth caused by a temporary indentation in a skin surface. The sonar sensor171also detects the change in depth using acoustic measurement.

While shown separately inFIG.1, any combination of the one or more sensors130can be integrated in and/or coupled to any one or more of the components of the system100, including the control system110, the user device170, or any combination thereof. For example, the acoustic sensor141and/or the RF sensor147can be integrated in and/or coupled to the user device170. In such implementations, the user device170can be considered a secondary device that generates additional or secondary data for use by the system100(e.g., the control system110) according to some aspects of the present disclosure. In some implementations, at least one of the one or more sensors130is not coupled to the control system110or the user device170. Sensor data may be transferred to the control system110from the uncoupled sensor130via indirect means of communication, e.g., via a flash drive, an external hard drive, etc.

The user device170includes a display device172. The user device170can be, for example, a mobile device such as a smart phone, a tablet, a laptop, or the like. Alternatively, the user device170can be an external display system, an external user input system, a television (e.g., a smart television) or another smart home device (e.g., a smart speaker(s) such as Google Home, Amazon Echo, Alexa etc.). In some implementations, the user device is a wearable device (e.g., a smart watch). The display device172is generally used to display image(s) including still images, video images, or both. In some implementations, the display device172acts as a human-machine interface (HMI) that includes a graphic user interface (GUI) configured to display the image(s) and an input interface. The display device172can be an LED display, an OLED display, an LCD display, or the like. The input interface can be, for example, a touchscreen or touch-sensitive substrate, a mouse, a keyboard, or any sensor system configured to sense inputs made by a human user interacting with the user device170. In some implementations, one or more user devices can be used by and/or included in the system100.

While the control system110and the memory device114are described and shown inFIG.1as being a separate and distinct component of the system100, in some implementations, the control system110and/or the memory device114are integrated in the user device170. Alternatively, in some implementations, the control system110or a portion thereof (e.g., the processor112) can be located in a cloud (e.g., integrated in a server, integrated in an Internet of Things (IoT) device, connected to the cloud, be subject to edge cloud processing, etc.), located in one or more servers (e.g., remote servers, local servers, etc., or any combination thereof.

While system100is shown as including all of the components described above, more or fewer components can be included in a system for generating physiological data and determining a recommended notification or action for the user according to implementations of the present disclosure. For example, a first alternative system includes the control system110, the memory device114, and at least one of the one or more sensors130. As another example, a second alternative system includes the control system110, the memory device114, at least one of the one or more sensors130, and the user device170. Thus, various systems can be formed using any portion or portions of the components shown and described herein and/or in combination with one or more other components.

Referring toFIG.2, the system disclosed above is illustrated by way of example in the form of a mobile phone200, but other camera-enabled electronic devices may also be used. One or more of the electronic devices have a control system including one or more processors configured to execute machine-readable instructions, such as upon activating the edema test, locating for a user a skin area of a subject for testing of edema; in response to locating the skin area, instructing the user to depress the skin area for causing a temporary indentation; capturing one or more images of the temporary indentation during an elapsed time period in which the skin area bounces back to a full or partial undepressed state; analyzing the one or more images for characteristics of skin bounce-back; determining an edema result based on the characteristics of the skin bounce-back; etc.

The mobile phone200is configured to initiate an edema test in a subject201, which in this example is a patient in a home environment203. The mobile phone200facilitates in a user-friendly, simple manner the taking of the edema test in one or more skin areas205of the patient201. Examples of the skin areas205for the edema test are located in a thigh area207or a calf area209of either leg of the patient201. According to other examples, the skin areas205are located on an arm or a foot of the patient201. The edema test, as disclosed in more detail below, is administered by the patient201or by a third-party, such as a family member or a medical professional (e.g., a doctor, a nurse, a trained specialist, etc.). Although in this example the edema test is described in a home environment203, according to optional or alternative examples the edema test is administered in others environments, such as a medical facility (e.g., a hospital, a doctor's office, etc.).

Referring toFIG.3, the mobile phone200has a display device272via which the patient201(or a third-party user, such as a medical doctor, nurse, or caregiver) interacts for performing the edema test. The display device272guides the patient201through the steps of the edema test, which may include starting with an activation step illustrated via an activation icon211. Optionally, the display device272shows an initial augmented reality (AR) screenshot in which the skin areas205are identified for the patient201as potential test locations.

Referring generally toFIGS.4-12, the edema test will be described in more detail. The edema test includes user input in which a user request is received for activating the edema test, and user instructions for guiding the user through the procedural steps of the edema test.

Referring specifically toFIG.4, the edema test is activated by pressing the activation icon211. In an alternative implementation, the edema test may automatically be activated by, for example, accessing or opening the test, such as on the mobile phone200, and the user request therefore comprises the user accessing or opening the test. The activation step is performed in response to receiving a user request via the display device272, which here operates as at least a portion of an electronic interface219. The display device272of the mobile phone200functions in accordance with the display device172illustrated inFIG.1, and the electronic interface219of the mobile phone200functions in accordance with the electronic interface119illustrated inFIG.1. In this example, the user request is received by pressing the activation icon211on the display device272.

Optionally, in addition or alternative to the pressing of the activation icon211, an audible command is received in a microphone240from the patient201(or other third-party). Optionally yet, the activation of the edema step is confirmed with an audio message213emitted by the mobile phone200via a speaker242. The microphone240of the mobile phone200functions in accordance with the microphone140illustrated inFIG.1, and the speaker242of the mobile phone200functions in accordance with the speaker142illustrated inFIG.1.

Referring specifically toFIG.5, upon activation of the edema test, the edema test procedure provides user instructions in which one or more of potential skin areas205are located in the patient201for testing. The mobile phone200scans via one or more of its sensors the patient201to find potential targets for the test in body of the patient201. The one or more sensors include one or more of the sensors described above in reference toFIG.1, including, for example, a camera250(illustrated inFIG.14) that functions in accordance with the camera150illustrated inFIG.1. While locating the test area, the edema test optionally shows a finding (or location) icon215on the display device272. For clarity, it is noted that the potential skin areas205are artificially superimposed as augmented reality (AR) icons over a live display of the body of the patient201. Thus, the circular icons displayed inFIG.5(referenced as skin areas205) are only viewable on the mobile phone200, superimposed over the physical, live display of the body of the patient201.

Referring specifically toFIG.6, after scanning the patient201and locating one or more potential test area targets, one of the located skin areas205is selected for the edema test. The selected skin area205is automatically selected in response to the scanning of the patient201, or is manually selected by the patient201(or other third-party). In the illustrated example, a determination is made that the skin area205in a heel portion217of the foot of the patient201is the best location. Optionally, a “best location” icon219is presented on the display device272.

Referring specifically toFIG.7, after locating the skin area205for the edema test, a depression icon221is provided that instructs the patient201(or other third-party user) to depress the located skin area205for causing a temporary indentation227(shown inFIG.8) in the skin of the patient201. The depression, according to this example, is optionally caused by a finger223pressed against the skin area205. Alternatively, as described in more detail below, a physical probe is used for forming the temporary indentation227(shown inFIG.8).

Referring specifically toFIG.8, after removing the finger223(shown inFIG.7) from the skin area205, an image capturing icon225indicates that one or more images or being captured via at least one of the sensors of the mobile phone200(e.g., the camera250illustrated inFIG.14). As illustrated in this exemplary embodiment, the image capturing icon225provides a request to “Hold Camera steady” because the mobile phone200is “Taking photo(s)” of the temporary indentation227caused in the heel portion217. Optionally or alternatively, a similar or identical audio indication229is provided via the speaker242. The images capture in real time the change in depth of the temporary indentation227as the skin area205rebounds.

Referring specifically toFIG.9, the edema test captures a plurality of images231, which include at least three images231a-231cshowing rebounding of the skin area205over a period of time following the depression of the skin area205. The rebounding, depending on severity and/or presence of edema, manifests itself via certain characteristic of skin bounce-back after causing the temporary indentation227. The characteristics are dependent on the elapsed time after the causation of the temporary indentation227, and include, for example, depth and/or color of the temporary indentation227at a specific time interval.

According to one implementation, the images231are captured during a predetermined period of time, e.g., 60 seconds. According to another implementation, the images231are captured until the depth of the temporary indentation227is back to the original undepressed state of 0.0 mm. According to yet another implementation, the images231are captured until a predetermined depth is achieved, which is not necessarily the depth of 0.0 mm. The predetermined depth may be determined based on, for example, an initial depth of the temporary indentation227caused by the user (e.g., using a finger223or probe247as described herein) and from which initial depth the skin bounces back (once the finger223or probe247is removed from the skin area205).

According to a first image231a, at a time interval 0.15 seconds after causing the temporary indentation227, the depth of the temporary indentation227is 2.0 mm and shows a first discoloration. Thus, this first image231acaptures skin bounce-back between the temporary indentation227and a partial undepressed state, which represents a partial rebounding of the skin area205.

According to a second image231b, at a time interval 0.5 seconds after causing the temporary indentation227, the depth of the temporary indentation227is 1.0 mm and shows a second discoloration. The second discoloration is closer to a normal skin color than the first discoloration. Thus, this second image231bcaptures a subsequent elapsed period of time between the temporary indentation227and a subsequent partial undepressed state. The subsequent elapsed period of time of 0.5 seconds is longer than the initial elapsed period of time of 0.15 seconds. The subsequent partial undepressed state in which the depth of the temporary indentation227is 1.0 mm represents a subsequent partial rebounding of the skin area205. The subsequent partial rebounding of 1.0 mm is closer to the original undepressed state of 0.0 mm than the partial undepressed state of 2.0 mm.

According to a third image231c, at a time interval of one second after causing the temporary indentation227, the skin bounce-back is now back to normal with a 0.0 mm depth and no discoloration. Thus, the total time for achieving full or complete bounce-back of the skin was one second.

In addition to images captured after the causation of the temporary indentation227, one or more images are optionally captured before and/or during the depression of the skin area205. These additional images are useful in providing a comparison between a depressed and an undepressed state of the skin area205.

Referring specifically toFIG.10, the captured images231are analyzed to determine characteristics of the skin bounce-back, which represents the rebounding of the skin area215after the temporary indentation227. As illustrated in this exemplary embodiment, an optional analysis icon233provides an indication that the test is “Analyzing photo(s)” and is currently at “15%” of the analysis. Optionally or alternatively, a similar or identical audio indication235is provided via the speaker242.

The analyzed characteristics optionally include a compensation for an elapsed time during which the skin area205was obstructed from view, e.g., by the finger223(shown inFIG.7) or by a probe247(shown inFIG.13). The compensation optionally accounts, for example, an amount of time during which the finger223obstructed the temporary indentation227and the respective rebounding of the skin that has occurred during that amount of time. The compensation is automatically determined, using live imaging, or is predetermined based on general statistics and/or assumptions. For example, the compensation is based on the assumption that an average person obstructs the temporary indentation227for 0.5 seconds, during which the skin generally rebounds 1 mm.

Referring specifically toFIG.11, an edema result is displayed based on characteristics of the skin bounce-back analyzed in the captured images231of the mobile phone200. The edema result, for example, displays an edema score237that indicates a case of “1+ Mild Edema.” The edema result optionally provides a test follow-up recommendation239, which in this example recommends that the patient consult a doctor for treatment or change a medication. Although not illustrated, the edema result is optionally provided in audio form, similar to the audio indication235disclosed above in reference toFIG.10. It is further understood that test indications, including test instructions and results, are provided in visual and/or audio form in accordance with the above disclosure.

As already mentioned above, the edema result is optionally confirmed using physiological data of the patient detected via a PPG sensor. The physiological data are used to measure the perfusion index and, then, the perfusion index is correlated with the edema result. According to an alternative implementation, the characteristics of the skin bounce-back are further selected from a group consisting of oxygen data (e.g., perfusion index, SpO2, etc.) and flushness data. Thus, the edema result is optionally based one or more of bounce-back characteristics selected from PPG data, hemoglobin data, oxygen data, flushness data, and bounce-back data.

Referring specifically toFIG.12, further supplemental test follow-up options are presented. For example, after determining the edema result, a call option239is displayed to call a doctor, and a forwarding option241is displayed to send the captured images231to the doctor. The test follow-up options are manually accepted or are automatically implemented. For example, depending on the severity of the edema result, a phone call is automatically initiated or scheduled with a medical facility.

A menu icon243facilitates administering one or more subsequent edema tests and/or other options related to the present edema test. Optionally, the subsequent edema tests locate the same skin area for testing as the present edema test. The same skin area increases consistency and/or reliability of the test results.

Referring toFIGS.13and14, the mobile phone200is illustrated with an attachment that is in the form of a probe assembly245, for causing the temporary indentation227illustrated inFIG.7. Thus, according to this example, instead of using the finger223(as shown inFIG.7), the edema test uses the probe assembly245.

The probe assembly245includes the probe247that has a proximal end249reversibly attached to an exterior surface251of a housing253of the mobile phone200. The probe247further has a distal end255that is used to cause the temporary indentation227(shown inFIG.7). The distal end255is fixed relative to the proximal end249.

In addition to the probe247, the probe assembly245includes an attachment assembly257that reversibly fixes the proximal end249to the exterior surface251. The attachment assembly257includes an attachment base259mounted over an attachment plate261(shown inFIG.14) and fixed to the mobile phone200via an attachment latch263.

Referring specifically toFIG.14, the probe247is substantially cylindrical in shape and has an imaging conduit265that is at least in part transparent or translucent. The imaging conduit265extends through an interior portion of the probe247throughout a length L. The imaging conduit265is in visual communication with the camera250(shown inFIG.14) of the mobile phone200, generally along a line of sight depicted by the imaging conduit265.

The attachment assembly257provides a clearance for an illumination element267of the mobile phone200, which is typically in the form of a flash for the camera250. The clearance is achieved by a top slotted hole269of the attachment base259overlapping a bottom slotted hole271of the attachment plate261. Illumination from the flash267optionally illuminates a body part of the patient201during the edema test disclosed above. For example, the flash267illuminates skin areas205(shown inFIG.5) when locating the test area.

Optionally, the probe247is formed at least in part from a translucent and/or transparent material, which is the same as or similar to the imaging conduit265. For example, walls of the probe247, which extend between the proximal end249and the distal end255), are made from a translucent material and/or a transparent material. The translucent and/or transparent characteristic of the probe247advantageously allows illumination of a subject's skin, using ambient light, without requiring a dedicated light source, such as the illumination element267of the mobile phone200.

Referring toFIGS.15and16, the probe assembly245is used by to cause the temporary indentation227(shown inFIG.16). Thus, as already disclosed above, the temporary indentation227is achieved in various ways, including using the finger223(as shown inFIG.7) and the probe assembly245. According to this example, the distal end255makes contact with the skin area205and causes the temporary indentation227. As further illustrated in this example, an illumination dot269is formed by the flash267(illustrated inFIG.14) to visually and precisely identify the skin area205for the user201on the body of the patient201.

Referring generally toFIGS.17-19, according to an alternative embodiment, the probe247has a movable element269having a movable distal end271for causing the temporary indentation227(shown inFIG.8). The movable element269moves relative to the housing253of the mobile phone200. A movable proximal end273(shown inFIGS.18and19) of the probe247is closer to the housing253than the movable distal end271.

Referring more specifically toFIGS.18and19, the movable distal end271is supported by a biasing element275. According one example, the biasing element275is a spring that extends between (a) a fully extended mode in an original undepressed mode (as illustrated inFIG.18) and (b) a compressed mode when the temporary indentation227(shown inFIG.8) is caused (as illustrated inFIG.19). For example, in the fully extended mode the movable distal end271is at a first distance X1from a top surface277of the housing253. In the compressed mode, the movable distal end271is at a second distance X2from the top surface277. The first distance X1is greater than the second distance X2.

To aid in measuring movement, internal marks279are provided internally within the movable element269. As the movable element269is depressed, such as when pressing against a skin surface205(as illustrated inFIG.16), the internal marks279provide a visual gauge for determining the depth of the caused temporary indentation227(also shown in inFIG.16).

Referring generally toFIGS.20-22, the probe247has various optional features near its distal end255. According to the example illustrated inFIG.20, a plurality of protrusions281that extend from an end surface283of the distal end255. The protrusions281form a specific pattern when causing the temporary indentation227(illustrated inFIG.16). Relative to a general flat surface, the protrusions281form an irregular surface for causing the temporary indentation.

According to the example illustrated inFIG.21, the distal end255includes a fisheye lens285for capturing wide-angle images. Optionally, the fisheye lens285includes at least one filter for providing various visualization of the captured images. For example, the fisheye lens285includes a first filter287for capturing an image of a first color and a second filter289for capturing an image of a second color. According to the example illustrated inFIG.22, the distal end255has a half-sphere shape291with a flattened top portion293. The flattened top portion291provides a precise, focused area of contact for causing temporary indentation227(illustrated inFIG.16), while the half-sphere shape291provides a wider-angle for the captured image.

Referring toFIG.23, an edema test procedure300is illustrated according to some implementations of the present disclosure. The edema test procedure can be implemented using any combination or aspects of the systems described herein. At step302, the edema test is activated in response to receiving a user request via an electronic interface. At step304, upon activation of the edema test, user instructions are provided. The user instructions include locating via at least one of one or more sensors a skin are in a subject for testing. At step306, the user is instructed to depress the skin area for causing a temporary indentation. At step308, one or more images are captured of the temporary indentation, via at least one of the one or more sensors. The images are captured over a period of time following the depression of the skin area by the user. At step310, the images are analyzed for characteristics of skin bounce-back, which represents rebounding of the skin area after the temporary indentation. At step312, an edema result is determined based on the characteristics of the skin bounce-back.

According to one or more illustrative embodiments, any of the systems or methods described above further detect or monitor edema in a subject in response to treatment of at least one edema-related condition. The edema-related condition is selected from a group consisting of one or more sleep-related conditions and/or respiratory-related conditions. For example, the detecting or monitoring of edema occurs before, during, or after the treatment of the sleep-related conditions and/or respiratory-related conditions. By way of further example, at least one of the conditions is one or more of a Disordered Breathing condition and a Chronic Obstructive Pulmonary Disease (COPD) condition.

According to one or more illustrative embodiments, any of the systems or methods described above further detect or monitor edema in a subject in response to treatment of lymphedema. For example, the detecting or monitoring of edema occurs before, during, or after the treatment of the lymphedema. The lymphedema includes primary lymphedema or secondary lymphedema. The primary lymphedema is caused by one or more of Milroy's disease, Meige disease, or Late-onset lymphedema. The secondary lymphedema is a result of a procedure or condition that results in damage or removal of lymph nodes or lymph vessels. For example, the secondary lymphedema is caused by one or more of a surgical operation, cancer, radiation treatment, or infection of the lymph nodes.

Devices, methods, and/or garments used in the treatment of lymphedema are described in, for example, PCT/US2019/055474 and WO2020/077008, each of which is hereby incorporated by reference herein in its entirety. For example, lymphedema treatments include compression therapy, which is optionally administered with a compression garment as described in PCT/US2019/055474 and WO2020/077008.

One or more elements or aspects or steps, or any portion(s) thereof, from one or more of any of claims1-87below can be combined with one or more elements or aspects or steps, or any portion(s) thereof, from one or more of any of the other claims1-87or combinations thereof, to form one or more additional implementations and/or claims of the present disclosure.

While the present disclosure has been described with reference to one or more particular embodiments or implementations, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present disclosure. Each of these implementations and obvious variations thereof is contemplated as falling within the spirit and scope of the present disclosure. It is also contemplated that additional implementations according to aspects of the present disclosure may combine any number of features from any of the implementations described herein.