System for acquiring ultrasound images of internal body organs

Abstract

A system for acquiring ultrasound images of an internal body organ includes a scanner and at least one inertial measurement unit (IMU) associated with the scanner, the system being configured to issue instructions to an operator of the system that enable the scan to be performed by a person untrained in ultrasound scanning, including the patient themselves, and once the scan is performed by the untrained operator, the scan is transmitted to a remote location for analysis by a medical professional.

Description

[Technical Field]

[0001] The present invention originates from the field of medical devices, and in particular relates to a system and method for properly positioning and moving a handheld ultrasound probe using an inertial measurement unit. [Background technology]

[0002] Knowing the location of a medical sensor or device relative to a patient's anatomy, and the speed at which the sensor or device is moving or should be moving, is important to the function of advanced remote-controlled, robotic, autonomous, self-feedback, or other automated medical procedures.

[0003] The speed at which an ultrasound probe (variously referred to herein for simplicity as a "scanner," "ultrasound head," or simply "probe") moves across the body provides important information. For example, images taken slower or faster than a certain range may be deleted or, in some cases, may be subject to special filtering and image processing techniques to enhance blurred images. Instructions may also be given to the operator regarding certain aspects of the procedure, such as when to stop motion, how to correct the scan path, how to change orientation or tilt the probe, etc. When remotely controlling an ultrasound probe or sensor mounted on a gimbal placed on the patient's body, knowing the two- or three-dimensional speed at which the ultrasound probe moves is also important for tracking the overall location, attitude, and velocity of the gimbal and / or probe.

[0004] A very common procedure is the ultrasound scan, which nearly every woman undergoes during a prenatal visit to her primary care physician or clinic. Typically, in this scenario, an ultrasound technician (sonographer) or physician performs the scan. Based on their experience, the operator—technologist, midwife, primary care physician, or sonographer—knows the best position and orientation in which the scanner head or probe must be placed to image specific embryonic structures, the correct amount of abdominal pressure needed to maintain good coupling of the scanner to the body, the angle of the probe relative to the abdomen, and the correct scanning speed to enable good imaging. Furthermore, the operator can view the images generated by the probe on a screen in real time and optimize or correct its position. Herein, the term "probe" or "ultrasound probe" refers to any useful probe, linear or convex phased array, HIFU, or other sensor.

[0005] In the context of this specification, the term "scanner" shall be understood to refer to an element, housing or device that must be moved over the surface of a patient's body in order to obtain data therefrom, such as an ultrasound image.

[0006] Many scans are performed simply to monitor embryonic vitality signs, such as heart rate, movement, amniotic fluid volume, sounds, and breathing. These scans may also be performed by the patient at home or other locations that are not clinics, hospitals, or medical facilities, thus saving overburdened healthcare system time and resources and potentially avoiding unnecessary visits to emergency departments or prenatal visits to primary care physician offices, clinics, or hospitals. However, performing ultrasound scans requires some skill on the part of the ultrasound operator that untrained individuals do not possess. Clearly, it would be highly desirable to provide a means by which unskilled individuals can perform "do-it-yourself" ultrasound scans that produce useful results. Summary of the Invention [Problem to be solved by the invention]

[0007] It is therefore an object of the present invention to provide a device and method that assists a patient in performing an ultrasound scan by monitoring the movement of the scanner head (ultrasound probe) and providing feedback to assist in positioning the scanner head at a desired location.

[0008] Further objects and advantages of the present invention will become apparent as the description proceeds. [Means for solving the problem]

[0009] In one aspect, the present invention provides a system for acquiring ultrasound images of an internal body organ, the system comprising a scanner and at least one inertial measurement unit (IMU) associated with the scanner, the system configured to issue instructions to an operator of the system that enable the scan to be performed by a person untrained in ultrasound scanning, including the patient themselves, and once performed by the untrained operator, the scan is transmitted to a remote location for analysis by a medical professional.

[0010] In some embodiments, the system comprises a component independent of the IMU that is adapted to alert the user if the coupling between the device and the body is insufficient, hi other embodiments, the system comprises a component independent of the IMU that is adapted to alert the user if the scanning rate is too fast.

[0011] In another aspect, the present invention encompasses a system for acquiring ultrasound images of an internal body organ, the system comprising a scanner and at least one inertial measurement unit (IMU) associated with the scanner.

[0012] In some embodiments of the system, the at least one IMU is one of: a) integral with the scanner; b) connected to the scanner via a plug-in connection; and c) disposed within an element associated with the scanner and moves with the scanner during scanning.

[0013] Some embodiments of the system are configured to issue instructions to the system operator that allow scanning by people untrained in ultrasound scanning, including the patient themselves.

[0014] In some embodiments of the system, the scans are performed by an untrained operator and the scans are transmitted to a remote location for analysis by a medical professional.

[0015] Some embodiments of the system are configured to enable two-way communication between an operator and a remote individual or unmonitored system, where the unmonitored system includes automatic image analysis circuitry. As used herein, the term "monitored" means that human supervision is present in the system. Conversely, an "unmonitored" system is fully automatic and does not include human supervision. Two-way communication can be selected from audio, visual, and video communication, and combinations thereof. In some embodiments of the system, when a scan is performed by an untrained operator, two-way video communication is enabled between the operator and a medical professional, allowing the operator and medical professional to see each other while the operator is performing the scanning procedure to assist the medical professional in interpreting the images and providing advice, if necessary. In some embodiments, the system is configured so that the output of the system is transmitted directly to the remote medical professional and / or the unmonitored system, either in real time or immediately after the images are acquired.

[0016] Some embodiments of the system are configured to overlay an image from the scanner onto the ultrasound scan to assist a medical professional in interpreting the image.

[0017] A scanner embodiment of the system includes a housing ergonomically designed to be held by an operator and moved across the skin of a human or animal. Some embodiments of the housing include or are associated with at least the minimum number of system components that must be placed on a patient's body to obtain ultrasound images. In some embodiments of the housing, the minimum number of components within or associated with the housing are: i) an ultrasound probe head; ii) at least one IMU including a three-axis accelerometer and a three-axis gyroscope; iii) electronic components for wired or wireless communication with a remote terminal; and iv) a power source.

[0018] In some embodiments of the system, the housing includes other components that can be arranged in many different configurations, at least some of which may be located within the housing. In these embodiments, the other components of the system include: v) an analog front end (AFE) that transmits and receives ultrasound signals using electronic components; vi) a processor including software; vii) a user interface that includes a display screen and means for accepting user instructions; and viii) at least one memory device for storing data and images processed by the software in the processor. In these embodiments, the other components not located within the housing are located in a location near the patient but separate from the housing. In these embodiments, the other components not located within the housing communicate with components located within or associated with the housing.

[0019] In some embodiments of the system, the electronic components of the AFE include a transmitter, a receiver, an amplifier, and analog-to-digital (A / D) and digital-to-analog (D / A) converters.

[0020] In some embodiments of the system, software is configured to operate the system to receive and process ultrasound signals received from the AFE to generate ultrasound images, and to receive and process inertial measurement signals received from the IMU.

[0021] In some embodiments of the system, the AFE, IMU, processor, memory device, and communication components may be provided as separate integrated circuits (ICs) or may be integrated into one or more ASICs that include at least some of the ICs.

[0022] Some embodiments of the system include additional components, including ix) a remote terminal, x) at least one additional IMU, xi) at least one magnetometer, xii) at least one pressure sensor, and xiii) at least one of a speaker and a microphone for communicating with a remote healthcare provider. The magnetometer may be a single-axis, two-axis, or three-axis magnetometer.

[0023] In some embodiments of the system, all of the other components v)-viii) are contained within a remote terminal that is connected to the scanner via a wired or wireless communication link. In other embodiments of the system, some of the other components v)-viii) are contained within the scanner, and the remaining components are located within a remote terminal that is connected to the scanner via a wired or wireless communication link.

[0024] In some embodiments of the system, the remote terminal is a portable communication device. In some embodiments of the system, the portable communication device is a smartphone. In some embodiments of the system, the portable communication device includes a display, an IMU, and a processor. In some embodiments of the system, the portable communication device fits into a socket in a housing of the scanner. In some embodiments of the system, the portable communication device is an integral part of the housing. In some embodiments of the system, the portable communication device is not an integral part of the housing, but fits into a socket in the housing before a scan is performed, is moved with the housing during the ultrasound scan, and is later removed for other uses, if desired. In some embodiments of the system, the portable communication device is connected to the housing via a cable or wireless connection, and only the housing is moved.

[0025] Illustrative examples of suitable wired communication links include USB, lightning, and fiber optics, although any additional wired communication is possible. Illustrative examples of wireless communication links include, but are not limited to, Wi-Fi, UWB, Bluetooth, and IR.

[0026] The portable communication device can be any of a number of suitable devices, for example, a mobile phone, a tablet, a laptop, etc. Additionally, the housing or a device connected to the housing may be adapted to receive data generated by the housing or communicate with an apparatus located in the cloud that is associated with the housing.

[0027] In some embodiments of the system, different combinations of one or more IMUs, processing devices and software, memory devices, power sources, and AFE components are located either within the housing or within the smartphone. Some embodiments of the system include at least one IMU within the smartphone and at least one IMU within the housing.

[0028] In some embodiments of the system, the processor is configured to receive data collected by all of the sensors.

[0029] In some embodiments of the system, the software is configured to perform at least one of generating ultrasound images, analyzing the data, determining which images are of sufficient quality to be displayed on a display screen, discarding low-quality images, instructing the operator to hold the scanner housing in a predetermined manner, calculating the location and orientation of the scanner, determining whether the scanner is being held so that sufficient pressure is exerted on the skin to produce images of sufficient quality, and effectively providing instructions on how to properly move the scanner to obtain satisfactory results.

[0030] In some embodiments of the system, instructions to the operator are generated by the software and are provided visually on a display screen or audibly through a speaker. In some embodiments of the system, instructions to the operator are provided visually on a display screen or audibly through a speaker by a trained medical professional located at a remote terminal.

[0031] In some embodiments of the system, the task of calculating navigation, including the location, orientation, and their time derivatives of the scanner, is performed by an Inertial Navigation System (INS) comprising a set of three-axis gyroscopes and three-axis accelerometers in an IMU and other sensors, a processor, and software, the INS configured to calculate navigation by incorporating initial conditions and calibration data and outputs from the IMU and other sensors, which may be at least one of a three-axis magnetometer, a pressure sensor, and a camera.

[0032] Some embodiments of the system are configured to generate accurate scans of ultrasound signals on the skin, using a combination of pressure sensors and IMUs to ensure images of sufficient value for diagnostic purposes by selecting only those images that meet optimal values ​​for the speed and pressure of the scanner's scan against the skin.

[0033] In some embodiments of the system, the INS provides the following types of data: a.Angle of orientation, b. Scanner speed, and c. Location of the ultrasound probe head relative to the body anatomy.

[0034] In some embodiments of the system, the scanning velocity is calculated from the angular velocity assuming the motion is perpendicular to the surface of the body.

[0035] In some embodiments of the system, for prenatal screening, the body is modeled as a sphere, and the radius of the sphere can be approximated by one or more of the patient's BMI, stage of pregnancy, or a visual estimate, for example, in the range of 20 cm to 70 cm for obese patients.

[0036] In some embodiments of the system, typical scanning distances are in the range of a few millimeters to tens of centimeters, and in some embodiments of the system, scanning speeds are in the range of 1 mm per second to several centimeters per second.

[0037] In some embodiments of the system, the IMU's three-axis gyroscope and three-axis accelerometer are calibrated by the manufacturer for offset, scale factor, cross-axis sensitivity, and initial orientation, and the MEMS IMU is calibrated by the user before each scan. In some embodiments of the system, if the scanning motion is slow and the operator maintains the scanner's orientation relative to the body being scanned within a few degrees of a predetermined starting orientation, a one-step calibration is required in which only the gyroscope offset is estimated; the one-step calibration process involves holding the IMU stationary for several minutes and recording the outputs of the sensors; the average output of the gyroscopes is taken to be their offset, and the variance of each sensor is taken to be its noise.

[0038] In some embodiments of the system, the operator performs a seven-phase calibration process, and the seven phases of the calibration process in a coordinate system with positive Z-axis pointing up, positive Y-axis pointing right, and positive X-axis pointing forward are as follows: a. Phase 1: Hold the scanner stationary for T seconds; b. Phase 2: Rotate the scanner about the Y axis such that the rotation is completed within T seconds and the scanner is stationary in the new orientation; c. Phase 3: The scanner is held stationary for T seconds, then rotated in reverse; d. Phase 4: Rotate the scanner around the X axis within T seconds; e. Phase 5: The scanner is held stationary for T seconds, then rotated in reverse; f. Phase 6: Rotate the scanner around the Z axis within T seconds; g. Phase 7: The scanner is held stationary for T seconds, then rotated in reverse.

[0039] In some embodiments of the system, if the processor determines that sufficient pressure is not being applied to the skin during scanning, instructions to increase pressure are issued to the operator either visually on the display screen, for example by displaying a downward arrow, and / or audibly through a speaker. In these embodiments, the processor can determine that sufficient pressure is not being applied to the skin by at least one of the following: a. analyzing the image and determining that the photograph is flat; b. Measuring the variance of the image brightness across several regions of interest within the image and determining that the variance is less than a threshold.

[0040] In some embodiments of the system, the processor includes software configured to determine whether an insufficient amount of aqueous gel has been placed between the ultrasound probe head and the skin and to issue an alert to the operator either visually on a display screen and / or audibly through a speaker. In these embodiments, the software can determine whether an insufficient amount of aqueous gel has been placed between the ultrasound probe head and the skin by determining whether there is attenuation of the signal returning to the probe or whether there is attenuation of the resulting ultrasound image.

[0041] In some embodiments of the system, the processor and software of the system are configured to issue the following set of instructions to guide the operator to perform the scan: a. instructing the operator to perform the calibration procedure when necessary by guiding the operator through the calibration procedure; b. instructing the operator to measure the patient's blood pressure using a sphygmomanometer; c. instructing the operator how to position the patient for the scan; d. instructing the operator to position the scanner at a location that will serve as the center of the patient coordinate system; e. Instructing the patient to operate the scanner so that the screen faces the patient; f. providing instructions to the operator including the direction in which to move the scanner over the surface of the patient's body, the distance to move in each direction, the speed at which the scanner should be moved, and the amount of force to apply to compress the scanner against the body; g. Advising the operator that the session is finished when sufficient images of sufficient quality have been collected; and h. If not done automatically, advise the operator to transmit the images to a medical professional for interpretation.

[0042] In a second aspect, the present invention encompasses a method for enabling an operator untrained in ultrasound scanning to acquire and process ultrasound images of an internal body organ. The method includes: a) providing a system comprising a scanner and at least one inertial measurement unit (IMU), the scanner being a component of the system that is moved by an operator over a surface of a patient's body to acquire ultrasound images, the at least one IMU being disposed within the scanner, the system being configured to issue instructions to the operator of the system that enable a scan to be performed; b. Follow the instructions issued by the system.

[0043] In one embodiment of the method of the second aspect, the system is the system of the first aspect of the invention.

[0044] In one embodiment of the method of the second aspect, the system-issued instructions are instructions issued by the processor and software of the system of the first aspect of the invention.

[0045] In a third aspect, the present invention encompasses a method for acquiring ultrasound images of an internal body organ, the method including providing a scanner and at least one inertial measurement unit (IMU) associated with the scanner, and instructions for operating the scanner to an untrained user.

[0046] Some embodiments of the third aspect of the method include issuing instructions to an operator of the system that enable the scan to be performed by a person untrained in ultrasound scanning, including the patient themselves. Some embodiments of the method of the third aspect include transmitting the ultrasound images being acquired to a remote location for analysis by a medical professional. Some embodiments of the method of the third aspect include providing circuitry adapted to perform two-way communication between a user and a remote individual or an unmonitored system. In some embodiments of the third aspect of the method, the unmonitored system includes automatic image analysis circuitry, and output of the automatic analysis is provided to the user and / or the medical professional. In some embodiments of the third aspect of the method, the two-way communication is selected from audio, visual, and video communication, and combinations thereof.

[0047] In some embodiments of the third aspect of the method, the scan is performed by an untrained operator and the system allows two-way video communication between the operator and a medical professional. In some embodiments of the third aspect of the method, the output of the system is transmitted in real time or immediately after the image is acquired to a remote medical and / or unsupervised system professional.

[0048] In some embodiments of the third aspect of the method, the system allows an image from the scanner to be overlaid onto the ultrasound scan to assist a medical professional in interpreting the image.

[0049] In some embodiments of the third aspect of the method, the method includes performing a calibration process consisting of seven phases in a coordinate system in which the positive Z axis points up, the positive Y axis points right, and the positive X axis points forward, the seven phases being as follows: a. Phase 1: Hold the scanner stationary for T seconds; b. Phase 2: Rotate the scanner about the Y axis such that the rotation is completed within T seconds and the scanner is stationary in the new orientation; c. Phase 3: The scanner is held stationary for T seconds, then rotated in reverse; d. Phase 4: Rotate the scanner around the X axis within T seconds; e. Phase 5: The scanner is held stationary for T seconds, then rotated in reverse; f. Phase 6: Rotate the scanner around the Z axis within T seconds; g. Phase 7: The scanner is held stationary for T seconds, then rotated in reverse.

[0050] In some embodiments of the third aspect of the method, if the processor determines during scanning that sufficient pressure is not being exerted on the skin, instructions to increase pressure are issued to the operator either visually on the display screen, for example, by displaying a downward arrow, and / or audibly through a speaker. In these embodiments, determining whether sufficient pressure is being exerted on the skin can be by at least one of the following: a. analyzing the image and determining that the photograph is flat; b. Measuring the variance of the image brightness across several regions of interest within the image and determining that the variance is less than a threshold.

[0051] Some embodiments of the third aspect of the method include determining through software analysis whether an insufficient amount of aqueous gel has been placed between the ultrasound probe head and the skin, and if insufficient gel is found, issuing an alert to the operator either visually on a display screen and / or audibly through a speaker. In some embodiments of the third aspect of the method, the software can determine whether an insufficient amount of aqueous gel has been placed between the ultrasound probe head and the skin by determining whether there is attenuation of the signal returning to the probe or whether there is attenuation of the resulting ultrasound image.

[0052] Some embodiments of the third aspect of the method include guiding the operator to perform the scan by issuing the following set of instructions: a. instructing the operator to perform the calibration procedure when necessary by guiding the operator through the calibration procedure; b. instructing the operator to measure the patient's blood pressure using a sphygmomanometer; c. instructing the operator how to position the patient for the scan; d. instructing the operator to position the scanner at a location that will serve as the center of the patient coordinate system; e. instructing the operator to position the scanner so that the screen faces the patient; f. providing instructions to the operator including the directions in which to move the scanner over the surface of the patient's body, the distance to move in each direction, the speed at which the scanner should be moved, and the amount of force to apply to compress the scanner against the body; g. Advising the operator that the session is finished when sufficient images of sufficient quality have been collected; and h. If not done automatically, advise the operator to forward the image to a medical professional for interpretation.

[0053] All of the above and other features and advantages of the present invention will be better understood through the following illustrative and non-limiting description of embodiments of the invention, taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0054] [Figure 1] FIG. 1 shows four columns each containing plots of data relating to the calibration process. [Figure 2] Figure 1 shows the results of estimating the scanner orientation by applying an extended Kalman filter to calibrated gyroscope and accelerometer data. [Figure 3] FIG. 3 shows a repeat of a test similar to that shown in FIG. 2, but with measurements fed into the EKF without calibration. [Figure 4] FIG. 1 illustrates the angular velocity at which the scan is being performed and the tangential velocity derived from the angular velocity. [Figure 5] 10 is a schematic diagram of an embodiment in which a smartphone equipped with components of the system fits into a socket in the housing of a scanner of the system. FIG. [Figure 6] FIG. 6 shows a schematic diagram of a typical scene on the screen of a smartphone during scanning by the embodiment of the system shown in FIG. 5. [Figure 7A] Figure 1 is a screenshot showing the effect on the image of poor coupling between the ultrasound probe head and the patient's body. [Figure 7B] Figure 1 is a screenshot showing the effect on the image of poor coupling between the ultrasound probe head and the patient's body. [Figure 7C] Figure 1 is a screenshot showing the effect on the image of poor coupling between the ultrasound probe head and the patient's body. [Figure 8] Figure 10 is a screenshot showing the results of a blood pressure measurement superimposed on a scan. [Figure 9] 1A and 1B illustrate the movement of the scanner relative to the patient's body. [Figure 10]1 is a flow chart of the combined alert process. DETAILED DESCRIPTION OF THE INVENTION

[0055] The present invention will now be described in detail as a system and method that allows patients to perform ultrasound scans themselves. While a detailed obstetric and gynecological example is provided, those skilled in the art can easily adapt this example to other conditions and other organs, such as the cardiovascular system, lungs, kidneys, thyroid gland, liver, prostate, and bladder, as well as other sensors. Furthermore, while envisioned as a system for personal use in a home environment, due to its portability, the system can also be effectively utilized by individuals less trained in ultrasound scanning, such as by family members, in ambulances, or by untrained military personnel on the battlefield. Of course, trained individuals can also benefit from using the present invention as a first approximation before other, more sophisticated equipment becomes available to them.

[0056] The other sensors referenced above can include any type of sensor that generates data useful for improving and / or adds relevant information to that obtained through ultrasound imaging. For example, blood pressure (the importance of which in the context of the present invention is discussed further below) can be transmitted to a device of the present invention, where it can be combined or overlaid with other information or used to alert the user and / or medical personnel of any potential problems. Another example is a proximity sensor that can be used to alert the user if not enough pressure is being applied to the body by the housing, potentially resulting in flawed readings.

[0057] An additional example of a sensor useful in the context of the present invention is an image capture element that can be used, independent of the IMU component, to alert the user about coupling problems (e.g., due to insufficient pressure of the device against the body or insufficient gel) or when the user is scanning too quickly to produce a good quality image. The above-mentioned conditions, and others requiring user alerts, are detected via image processing that can be performed locally in the housing or remotely by a connected device.

[0058] The scan can be performed by the patient themselves and then transmitted to a remote location for analysis by a medical professional or an unsupervised system with automatic image analysis circuitry. Some embodiments of the system are configured to allow two-way video communication, i.e., telemedicine, allowing the patient and sonographer to see each other face-to-face while the patient is undergoing the scanning procedure.

[0059] The present invention also encompasses a system for acquiring and processing ultrasound images of internal body organs. The system is comprised of many components arranged in many different configurations, examples of which are described herein. The system component essential to all configurations is referred to herein as the "scanner," which includes the components of the system that are moved by an operator over the surface of a patient's body to acquire ultrasound images. Figure 9 illustrates possible forms of scanner movement relative to the patient's body. The scanner comprises a housing that is ergonomically designed to be held by an operator and moved across the skin of a human or animal. The housing comprises at least the minimum number of system components that must be placed on the patient's body to acquire ultrasound images. These elements can be integral with or associated with the housing. In the context of this specification, the term "associated with" should be interpreted to mean that the referenced element or component does not necessarily have to be integral with the housing, but must cooperate usefully with the housing. For example, when an accelerometer is discussed, the accelerometer must move with the housing, and when a communication component is discussed, the communication component must be in communication with any other components located within the housing with which it must exchange data or from which it must receive data. These components are: i) an ultrasound probe head, i.e., an array of ultrasound elements; ii) electronic components for wired or wireless communication with a remote terminal; iii) a power source, e.g., a battery when the system is wireless or a power supply in the case of a wired system; and, in most embodiments, iv) an inertial sensor, i.e., at least one inertial measurement unit (IMU) comprising a three-axis accelerometer and a three-axis gyroscope, and possibly other sensors, e.g., a three-axis magnetometer and a pressure sensor.

[0060] However, in some embodiments of the present invention, the inertial sensor is not integral with the housing. Instead, an inertial sensor (described below) from a smartphone or similar portable device can be used, or an add-on inertial sensor can be connected to the housing prior to use. In another embodiment of the present invention, the housing can be a "docking housing," i.e., a housing that includes only the essential components for connecting functional components, such as various types of sensors, to the housing, which can be connected to the docking housing as needed. This embodiment allows for the selection of an appropriate type of sensor for a given application, which can be added to the housing as a "plug and play" component.

[0061] Other typical components of the system are: v) an analog front end (AFE) that transmits and receives ultrasound signals via electronic components including, among others, a transmitter (pulser), a receiver, an amplifier, and analog-to-digital (A / D) and digital-to-analog (D / A) converters; vi) a processor containing software configured to operate the system and receive and process ultrasound signals received from the AFE to generate ultrasound images and inertial measurement signals received from the IMU; vii) a user interface including a display screen and means for accepting user instructions, such as a keyboard or touchscreen; and viii) one or more memory devices for storing data and images processed by the software in the processor. In different embodiments, some or all of these components may be located within the scanner housing or in a location near the patient but separate from the housing. Many options exist for arranging these components, as will be readily apparent to those skilled in the art.

[0062] The electronic components, i.e., AFE, IMU, processor, memory devices, and communication components, may be provided as separate integrated circuits (ICs) or may be integrated into another ASIC that includes all or part of those ICs.

[0063] Optional components of the system include ix) a remote terminal, such as a smartphone, tablet, PC, or similar communication and computing device, located near the operator or remotely from the operator, for example, in a clinic or primary care physician's office; x) one or more additional IMUs; xi) at least one magnetometer; xii) at least one pressure sensor; and xiii) a speaker and microphone for communicating with a remote healthcare provider.

[0064] In some embodiments of the system, all components v)-viii) are contained within the scanner housing (or on it, in the case of the display).

[0065] In some embodiments of the system, all components v) to viii) are contained within a remote terminal that is connected to the scanner via a wired or wireless communication link, which can be formed using any known technology, such as, for example, cellular, WIFI or Bluetooth.

[0066] In some embodiments of the system, some of components v) through viii) are included within the scanner, e.g., some or all of the components of the AFE, and the remaining components are located in a remote terminal connected to the scanner via a wired or wireless communication link.

[0067] FIG. 5 schematically illustrates an embodiment in which the display 10, IMU 12, and processor 14 are contained within a smartphone 16 that fits into a socket 18 within a housing 20 that contains the other components of the scanner. The smartphone 16 is not necessarily an integral part of the housing 20; rather, it may be fitted into the socket 18 prior to performing a scan, moved as an integral part of the housing 20 during ultrasound scanning, and later removed for other uses. The smartphone 16 is electrically connected to the housing 20 by a connector 22 within the socket 18 that fits into a standard port on the smartphone 16. An ultrasound probe head 24 can be seen at the bottom of the housing 20 in FIG. 5. As used herein, the term “smartphone” refers to any portable communication device that can create its mounting location within a housing such as the housing 20 of FIG. 5, and is not intended to limit the present invention to any particular type of communication device, existing or yet to be developed. Smartphones are chosen in this example solely to illustrate the present invention because they are a widespread device available to most people.

[0068] In another embodiment, the smartphone is connected to the housing via a cable or wireless connection and only the housing or the probe itself is moved, i.e. the smartphone does not necessarily move in unison with the ultrasound probe.

[0069] In other embodiments, different combinations of one or more IMUs, processing devices and software, memory devices, power sources, and AFE components are located either within the housing or within the smartphone.

[0070] Because IMUs are, on the one hand, very noisy and, on the other hand, relatively cheap, in some embodiments it is advantageous to use several of them in one scanner, for example one IMU in a smartphone, and another IMU in a housing, or two or more IMUs in a housing, which increases the accuracy of positioning and movement measurements and improves the signal-to-noise (S / N) ratio of the received ultrasound signals.

[0071] The processor is configured to receive data collected by all sensors and includes software configured to, among other things, generate ultrasound images, analyze the data, and in some embodiments determine which images are of sufficient quality to be displayed on the display screen, calculate the location and orientation of the scanner, discard low-quality images, instruct the operator to hold the scanner housing in a predetermined manner, e.g., so that the display screen (or designated symbols on the housing surface in embodiments where the display is remotely located) always faces toward the operator, determine whether sufficient pressure is being applied to the skin to produce images of sufficient quality, and effectively provide instructions to the operator on how to properly move the scanner to obtain satisfactory images via intuitive graphical cues presented on the display screen. In other embodiments, instructions to the operator are provided visually or audibly on the display screen and speaker or by a trained medical professional located at the remote terminal.

[0072] Figure 6 shows a schematic representation of a typical scene on the screen of a smartphone 16 during scanning by the embodiment of the system shown in Figure 5. In this exemplary embodiment, a blank area 26 is reserved on the screen for instructions from the system to the user. Typical instructions include, for example: - The screen is not facing you - keep the screen perpendicular to your body. - Image is blurry - Apply more pressure or add more gel. - You're moving too fast - slow down. - Move the housing to the right.

[0073] The task of calculating the scanner's location, orientation, and their time derivatives is performed by an inertial navigation system (INS), which consists of an IMU, i.e., a set of three-axis accelerometers and three-axis gyroscopes, and usually other sensors such as three-axis magnetometers and pressure sensors, a processor, and software configured to take initial conditions and calibration data and outputs from the IMU and other sensors to calculate navigation.

[0074] In addition to IMUs, magnetometers, and pressure sensors, other sensors can be used to improve accuracy. For example, a mobile phone has a front-facing camera facing the user and a rear-facing camera facing objects in a room. In one example, the smartphone fits into a socket in a housing containing the other components of the scanner, and at the start of a scan, the rear-facing camera is pointed at a specific object in the room. During the scan, the rear-facing camera moves with the housing, and its movement relative to the object in the image can be tracked using optical flow methods, providing additional information to the navigation algorithm that can be used to correct for errors.

[0075] In an embodiment of the present invention, the system can be configured to generate accurate scans of ultrasound signals on the skin, using a combination of pressure sensors and IMUs to ensure images of sufficient value for diagnostic purposes by selecting only those images that meet optimal values ​​for the speed and pressure of the scanner's scan against the skin.

[0076] These sensors in an Inertial Measurement Unit (IMU) or Inertial Navigation System (INS) can be implemented using a single chip ASIC that contains all or part of them, or as separate chips that implement each sensor separately or a combination of multiple sensors.

[0077] An IMU provides several types of data: 1. The angle of orientation used for: a) Providing instructions to the user on how to hold the scanner to get the best image. b) Providing the physician or other professional with the sequential orientation of the probe at the time the scan was taken to facilitate image interpretation. This information can be presented as an overlay on the ultrasound image. 2. The speed of the scanner used for: a) Providing instructions to the user on how to move the scanner to get the best image. This information can be given to the remotely located physician so that the physician knows how the scan is being performed with all the alerts the operator receives. b) Filtering out images that are unlikely to contain useful information. For example, the criterion for image removal may be a speed greater than 10 cm / sec, or even 1 cm / sec in situations where slow scanning is required to detect certain phenomena, such as self-scanning of the inferior vena cava (IVC) in patients with congestive heart failure (CHF). 3. Location of the ultrasound probe head relative to the body anatomy, used for: a) Providing instructions to the user on how to scan the entire region of interest to completely cover the organ of interest. b) To provide the physician or other professional with the sequential orientation of the scanner at the time the scan was taken to facilitate interpretation of the images.

[0078] IMUs, like other devices, are not perfect. IMU errors undergo integration, forming drift, i.e., errors that grow over time; therefore, errors in the calculated location and orientation propagate rapidly over time. An example can best illustrate this problem. Suppose, due to measurement noise and other imperfections, the device's orientation is known to within 1 milliradian of error. This error is considered very small, given the quality of the IMU in, for example, a typical smartphone. This error causes the processor to misinterpret the accelerometer readings and miscalculate the gravity projection by approximately 1 cm / sec. 2 This small acceleration error results in a location error of 18 meters over one minute, which is clearly well beyond the allowable error. Therefore, the processor must have some additional information and must assume some limits to provide meaningful navigation.

[0079] The IMU installed in a smartphone is based on Micro Electro-Mechanical System (MEMS) technology. MEMS technology offers tiny, efficient, and affordable sensors, but suffers from inherent imperfections that result in measurement errors. These errors can be divided into bias and noise. Formally, the only difference is that bias varies slowly, while noise varies rapidly. However, to illustrate this issue over the time period relevant to an ultrasound scan, bias can be thought of as constant and noise as absolutely random.

[0080] Therefore, due to bias, an IMU on a stationary device will still produce measurements as if the device were rotating and accelerating. A calibration procedure must be implemented to calibrate the IMU and account for the bias. Still, due to noise, no calibration is perfect and some residual bias always remains. Also, although the noise is random, it only goes to zero after an infinite number of measurements. In fact, the expected value of the noise is the square root of the number of measurements multiplied by the standard deviation of the noise.

[0081] As mentioned above, all IMUs installed in smartphones are MEMS-based, subject to strict constraints on cost, size and energy consumption, and are therefore very similar to each other: their noise and bias figures are essentially the same.

[0082] As a result of bias and noise, and given the quality of the MEMS IMU, the navigation process must integrate more measurements and utilize several prior assumptions to mitigate IMU errors. When scanning with a scanner, the distance traveled is small and the scanning speed is relatively slow, often resulting in the noise generated within the IMU being greater than the signal. Typical distances for these scans range from a few millimeters to tens of centimeters, and typical speeds range from 1 mm / sec to several centimeters per second. Therefore, successful navigation relies on optimal calibration and the integration of other available cues enabled by the system, mission, and user.

[0083] Some bias errors are calibrated at the manufacturing level. However, some biases change over time and must be calibrated before use. For the scanner described herein, the calibration process is limited to simple steps that can be easily performed by the user. A prior assumption that can be made is that the user will collaborate by holding the scanner on a horizontal table facing the display.

[0084] When the scanner is placed on a horizontal surface, the acceleration axis should be equal to 9.81° downward; therefore, if a value different from 9.81° is measured, the processor can calibrate this offset and add it to each measurement. If the user is required to calibrate the IMU, after the system is activated and before starting a scanning session, the user is instructed, either by software in the processor or by a remotely located technician, on how to calibrate the gyroscope and accelerometer. Because calibration values ​​change from day to day and each time the IMU is turned on, IMUs, especially those made with MEMS technology, must be calibrated before each use.

[0085] Here, we describe a calibration procedure involving seven phases. This procedure is one of many that can be used with the scanner and is intended merely to illustrate the principles involved. We anticipate that other calibration procedures involving fewer than seven phases may be devised and used, including procedures with different phase orders or more or fewer phases. The choice of the actual calibration method is not essential as long as it produces the desired calibration results. In many situations, particularly when only slow movements are permitted and the user keeps the screen pointed at themselves within a few degrees, a one-step calibration in which only the gyroscope offset is estimated provides excellent results. In this protocol, the IMU is held stationary for some time and the sensor outputs are recorded. The average gyroscope output is taken to be their offset, and the variance of each sensor is taken to be its noise. The Earth's rotation of approximately 15 degrees per hour is typically negligible compared to the gyroscope offset.

[0086] For this example, a coordinate system is chosen in which the positive Z axis points up, the positive Y axis points to the right, and the positive X axis points forward. The letter T is used for the duration of the calibration, which can be, for example, 1, 3, 5, or 10 seconds or more, depending on the type of IMU. The value of T is a compromise between accuracy and user patience. The procedure has seven phases: Phase 1: The scanner is held stationary for T seconds. Phase 2: Rotate the scanner about the Y axis such that the rotation is completed within T seconds and the scanner is stationary in the new orientation. Phase 3: The scanner is held stationary for T seconds, then rotated in reverse. Phase 4: The scanner is rotated around the X axis within T seconds. Phase 5: The scanner is held stationary for T seconds, then rotated in reverse. Phase 6: The scanner is rotated around the Z axis within T seconds. Phase 7: The scanner is held stationary for T seconds, then rotated in reverse.

[0087] During these seven phases, data from three accelerometers and three gyroscopes is collected by the electronics and transferred to a processor. An example of the gyroscope data is shown in Figure 1.

[0088] FIG. 1 shows four columns, each containing plots of data related to the calibration process. In each column, three rows refer to three gyroscopes, x, y, and z. In each plot in FIG. 1, the horizontal axis is the time of measurement, and the vertical axis is the measurement taken from the gyroscope or the error in this measurement. Vertical lines mark the boundaries between seven phases, labeled as follows: first SO, second RY, third SY, fourth RX, fifth SX, sixth RZ, and seventh SZ. The first letter, either S or R, refers to either the "stationary" or "rotating" situation. The second letter, either X, Y, or Z, refers to the axis about which rotation occurs or the axis about which rotation occurred prior to the stationary situation.

[0089] Referring to Figure 1, we can see how the data is interpreted. The leftmost column contains data collected from the gyroscope. In the first phase, S0, from time 0 to 5 seconds, the device is stationary and the gyroscope outputs their offset and any constant rotation, e.g., the Earth's rotation. In the second phase, RY, from time 5 to 10 seconds, the first 2.5 seconds show a 180-degree rotation around the y-axis. Therefore, the y-gyro shows a large signal. And so on for the other phases.

[0090] The next column, second from the left, shows the error in the measurements. Note that in this case, all gyroscopes sense either zero rotation or a known angular rate of 180 degrees, or approximately 1.26 rad / sec, over a 2.5 second period, so the error is apparent. In this column, three features of the signal are visible: the offset is better seen, there is a signal at the point of rotation on an axis other than the axis of rotation, and the output of the rotational gyro differs from prediction. The latter two phenomena arise from cross-axis measurements and scale factor errors.

[0091] The first phase, S0, from 0 to 10 seconds in this example, is stationary and should therefore yield zero, apart from the small contribution of the Earth's rotation. However, in this example, the measurements are taken at 10 seconds of the Earth's rotation. -4 The offset is approximately [0.12, -0.18, 0.02] rad / sec, including less than rad / sec. In a third phase, SY, data is taken from the same sensor after the sensor is rotated 180 degrees about the y-axis; in this case, the contributions of the Earth's rotation in the x- and z-axes are reversed. Thus, averaging the data at S0 and SY gives estimates of the offsets of the x- and y-gyros. A similar protocol applies to other axes using other rotations.

[0092] The next column, third from the left, shows the same data as the previous two columns after the calculated offset has been removed, so now quiescent conditions represent 0 rad / sec plus some noise.

[0093] By examining the third column, the cross-axis effect can be calculated. For example, the output of the x-gyro during the RY phase should be zero, and is actually approximately 0.013 rad / sec. The ratio between the average output of the x-gyro, i.e., approximately 0.013 rad / sec, and the average output of the y-gyro, i.e., approximately 0.126 rad / sec, produces a cross-axis effect between the y-axis and the x-axis of approximately 0.01. Similarly, the relationships of all nine cross-axis possibilities can be worked out.

[0094] A scale factor can also be calculated from the data in this column by comparing the error to the predicted result. For example, an error of 0.125 rad / sec is seen in the second row for phase RY. This error is approximately 0.1 of the signal, therefore the scale factor is 1.1.

[0095] The scale factor and cross axis can be combined into a matrix. Multiplying the original result by the inverse of this matrix and subtracting the original data produces a result in the last column that contains only noise. This noise is conveniently used to estimate the detector noise required by the extended Kalman filter.

[0096] Note that the angular velocity time constants shown here are only there to make this example clearer: replacing all calculations with their average over the duration of the phase yields the same results.

[0097] The algorithm used by the software in the processor to calibrate the gyroscope offset is as follows: 1. O_s0 = average of data collected in phase 1 for each of the three gyroscopes. 2. O_sy = average of data collected in phase 3 for each of the three gyroscopes. 3. O_sz = average of data collected in phase 7 for each of the three gyroscopes. 4. Calculate the following:

number

[0098] The algorithm used by the software in the processor to calibrate the gyroscope scale factor is as follows: 5. O_ry = average of data collected in phase 2 for each of the three gyroscopes. 6. O_rx = average of data collected in phase 4 for each of the three gyroscopes. 7. O_rz = average of data collected in phase 6 for each of the three gyroscopes. 8. Calculate the following:

number

[0099] The algorithm used by the software in the processor to calibrate the cross-axis sensitivity of the gyroscope is the matrix C ω Based on. 9. During the ceremony,

number

[0100] The algorithm used by the software in the processor to calculate the three projections of gravity onto the three accelerometers in the initial body coordinates is as follows: 1. A_s0 = the average of the data collected in phase 1 for each of the three accelerometers. 2. A_sy = average of data collected in phase 3 for each of the three accelerometers. 3. A_sz = the average of the data collected in phase 5 for each of the three accelerometers. 4. Calculate the following: a) x-projection of gravity = A_ref x =(A_s0 x -A_sy x ) / 2 b) y projection of gravity = A_ref y =(A_s0 y -A_sz y ) / 2 c) z projection of gravity = A_ref z =(A_s0 z -A_sy z ) / 2

[0101] Here, an Extended Kalman Filter (EKF) is used to estimate the scanner orientation.

[0102] State vector at time k

number

number

number

number

number

number

[0103] The measurement vector is:

number

number

number

number

number

number

[0104] Similarly,

number

number

[0105] C a and B a and C ω and B ω is calculated in the calibration process.

[0106] Implicitly, this filter is

number

[0107] Figure 2 shows the results of estimating the scanner's orientation by applying an extended Kalman filter to calibrated gyroscope and accelerometer data. The leftmost column shows the gyroscope output with a dotted line, the extended Kalman filter (EKF) estimate of rotation with a dashed line, and the true rotation with a solid line. Each row represents one axis: x, y, and z. The left column relates to angular velocity as measured in body-fixed coordinates. For example, looking at the top x-gyro, the true rotation is zero. The sensor produces approximately -0.18 rad / sec, resulting from the offset. Both the true rotation and the calibrated signal are close to zero. Note that for the y-axis, a true rotation of 0.1 rad / sec is applied. All measurements contain some noise, on the order of a few milliradians per second. Without a large offset or rotation, the noise is more easily seen in the z-gyro output, since the scale of the numbers shrinks to the noise level. The rightmost column shows the four elements of the quaternion used in the EKF to estimate orientation. Again, solid and dashed lines are used for the actual and estimated quaternions, which are very close to each other. The middle column shows the orientation in Euler angles, which are more easily interpreted. An angular velocity of 0.1 rad / sec is applied, so the y angle advances at this rate. The solid and dashed lines are so close that they are indistinguishable. The dynamics of the error can be better seen in the x and z angles, where some error accumulates as the y angle approaches 90 degrees. Of course, 180 degrees and -180 degrees refer to the same angle and are not an error. The accumulation of error as the y rotation approaches 90 degrees is not accidental, but arises from numerical effects. The conversion of quaternions to Euler angles uses inverse trigonometric functions and is very sensitive to the 90-degree angle.

[0108] Figure 3 shows a repeat of a test similar to that shown in Figure 2, but with measurements fed to the EKF without calibration. Errors in the signal, offsets in the y-axis, and cross-axis effects on the other axes can be observed. These errors translate into large errors in the y-angle and observable errors in the x- and z-angles.

[0109] Ultrasound scanning relies on holding the scanner so that some pressure is exerted on the skin. As the pressure is reduced, the scanner produces a flat image. A processor analyzes the image, whereupon it is concluded that the photograph is flat, or, instead of using the entire photograph, a similar criterion is used, such as measuring the variance of image brightness over some region of interest. If the brightness is less than a threshold, the processor issues instructions to the operator to increase the pressure. In one embodiment, this instruction may include, by way of example, the appearance of a downward-pointing arrow on the display screen accompanied by an audio instruction to increase the pressure on the skin.

[0110] Aqueous gels are commonly used to provide a smooth medium for the ultrasound beam to propagate from the probe to the body; otherwise, the beam is attenuated as it passes through air. The resulting signal or image can be used to determine whether there is sufficient coupling between the probe and the body. This can be determined, for example, by attenuation of the signal returning to the probe or the resulting ultrasound image. Figure 7A is a screen shot showing good coupling between the ultrasound probe head and the patient's body, while Figures 7B and 7C show examples of poor or partial coupling. This process can be performed within the mobile device's processor, the AFE's controller, the device's components including the ultrasound transducer, or external software.

[0111] The speed of the scan can be calculated from the angular velocity. The processor assumes motion perpendicular to the surface of the body. For prenatal screening, the body can be modeled as a sphere, e.g., R0=20, 30, 40, or even 70 cm for obese patients. The radius can be better approximated based on the patient's BMI and stage of pregnancy. The speed can be approximated as follows:

number

number

number

number

number

number

[0112] Figure 4 shows the angular velocity at which the scan is performed and the spatial velocity derived from the angular velocity. The third column of the figure shows the three components of velocity in radial coordinates along the abdomen of a pregnant patient. The x-axis refers to radial motion from the center of the abdomen outward. This motion is assumed to be zero. The y-axis refers to motion across the abdomen from bottom to top, and the z-axis refers to motion from right to left. The other columns show the same information as the three columns in Figure 2 and are provided for reference. The range of allowable velocities is a characteristic of the scanner and is typically a few centimeters per second. This slow motion generates radial accelerations as small as 1 millimeter per square second, which means that the acceleration of gravity can be used as a good approximation of downward acceleration by the EKF. Therefore, if the calculated velocity is not within the allowable range, the scan is discarded and instructions to slow down are issued to the patient.

[0113] Combining speed and orientation, the scanner can ensure that the user is instructed to cover a given range of angles and do so within the allowed speed range. In addition to the quality of the images produced by the imaging process, the appropriate pressure on the skin is also maintained. In short, this ensures a good examination.

[0114] In many cases, physicians or other trained medical professionals either directly observe the scan results or are given the scan for analysis, so it is important that they are given all the information they need to understand the data provided. For prenatal scans, blood pressure is measured at every prenatal visit. Therefore, the patient's blood pressure should also be measured at home, and the measurement results should be added to the ultrasound scan record. High blood pressure for gestational age is an important diagnostic finding and indicator of preeclampsia and is crucial for determining how the remaining pregnancy is managed before delivery, the timing of delivery, the risk of complications, and long-term maternal morbidity. This also impacts the manner in which the sonographer relates to the scan, as a low fetal heart rate and low maternal blood pressure may indicate a healthy fetus, while a low fetal heart rate and normal maternal blood pressure indicate a potentially ill fetus. Figure 8 is a screenshot showing one example of how blood pressure measurement results can be displayed to a physician or other trained medical professional both as a written message and as an overlay on the scan.

[0115] The scanner is a "black box" as far as the scanner operator is concerned. All of the algorithms mentioned above are useful only to the internal workings of the system, and the processor is programmed to utilize them to generate instructions for the patient to guide them through the process of acquiring ultrasound scans that are of sufficient quality to provide useful information. The patient simply needs to follow the visual or auditory instructions they receive from the system components or, in the case of telemedicine, from the sonographer. Video instructions can also be presented through animation.

[0116] In general, a typical set of instructions issued by the system to guide the operator to perform a scan includes the following: a) instructing the patient to perform a calibration procedure, if necessary, for example, by guiding the patient through a procedure such as the single-step or seven-step calibration procedure described herein; b) instructing the patient to measure the patient's blood pressure using a sphygmomanometer; c) instructing the patient how to position themselves for the scan, for example horizontally on their back for a prenatal scan; d) instructing the patient to position the scanner at a location that will serve as the center of the patient coordinate system, for example, above the navel for a prenatal examination, between the nipples for a cardiac scan, or three finger widths from the right or left nipple for a lung scan; e) instructing the patient to position the scanner so that the screen faces the patient; f) providing instructions to the patient including the directions in which to move the scanner over the surface of the patient's body, the distance to move in each direction, the speed at which the scanner should be moved, and the amount of force to be applied to compress the scanner against the body; g) Advising the patient that the session is over when sufficient images of sufficient quality have been collected; and h) Advising patients to forward images to a medical professional for interpretation if this is not done automatically.

[0117] In some embodiments of the invention, the scanner output may be transmitted directly to a medical professional, such as the patient's physician, in real time or immediately after the output is acquired, and some or all of the patient instructions may be transmitted by the physician, particularly if a particular region of the anatomy needs to be studied in more depth than is normally possible from a general scan. As an aid to the physician, in some embodiments of the system, software within the processor is configured to overlay the scanner image onto the ultrasound scan. In other embodiments, the processor is configured to relay instructions transmitted to the operator during the scan, so the physician can understand what instructions regarding the image are presented and when they are presented.

[0118] Example 1: Combined Alerts The following illustrates a combined alert procedure according to one particular embodiment of the present invention. The procedure includes the following steps: Image Acquisition - Construction of an ultrasound image from echoes received from the body organs to the transducer. b. Image Pre-Processing - At the start of the process, the frames undergo image pre-processing that normalizes the variance between frames from different scans. c. Total Black Frame (TBF) Test - After image preprocessing, the algorithm will perform a TBF test, in which the percentage of pixels that are absolutely black in the entire current frame is tested to find frames that qualify for the TBF criteria. d. Joint Condition Classification - Joint conditions on any side (left / right) of each frame are generated by a decision tree classifier. e. Buffer Test - Each classification is stored in a buffer for a length of 16 determinations. If 80% of the determinations show insufficient binding, the user is instructed to improve skin contact or add more gel. f. Alert the operator - While scanning, the user receives real-time feedback on the bond condition. If 80% of the frames have poor bond, the user is instructed to improve skin contact or add more gel. g. Add image to record - If a good join is detected, the frame is recorded. h. Alert Operator (TBF) - If no bond is identified, the system will guide the user to hold the cradle closer to the skin. i. Dropping images from recording - thus improving the received image if frames are not in TBF case. j. Display images on screen - All images are displayed on the screen (TBF, poor bonding and good bonding).

[0119] This process is illustrated in flow chart form in FIG.

[0120] Example 2: "Scanning too fast" alert The following provides a procedure for dealing with users who move the housing too quickly to produce good quality scans.

[0121] The following two steps are performed to obtain the value of the scanning velocity from the scanned image. a. Detecting changes in the bulk of the image; and b. Detecting optical flow to obtain velocity.

[0122] The first step aims to distinguish between embryo motion and scanner motion. Embryonic motion is localized, so they do not change large parts of the image. In contrast, scanner motion changes the entire image at once. To estimate the change, the standard deviation over time is calculated over six frames. If significant changes are detected in more than 0.5% of the total scanned pixels, this indicates that motion has occurred.

[0123] To assess the overall change in a photograph, the change per second in pixel intensity is evaluated across the image. The pixel standard deviation over time is used as an estimator of change. For an image I(x,y,n), "n" is the number of frames, and each frame is captured at time t(n). The following calculation is used to assess change:

number

[0124] This gives a measure of the amount of change per frame. To assess change over time, the value is normalized by the average FPS.

number

[0125] In the next step, the number of dramatically changed pixels is calculated.

number

[0126] Now the sum of C is calculated to understand what percentage of the image has changed.

number

[0127] For moving frames, optical flow is calculated using the Lucas-Kanade pyramid method. x , V y The central corner of the image is used in the calculation using a Harris corner detector.

[0128] Optical flow gives a velocity per frame. To reach that velocity in time, the velocity should be normalized by FPS.

number

[0129] Although embodiments of the invention have been described by way of example, it will be understood that the invention may be practiced with many variations, modifications and adaptations without departing from the scope of the claims.

Claims

1. 1. A system for acquiring ultrasound images of internal body organs, comprising: a scanner; at least one inertial measurement unit (IMU) associated with the scanner; and a component independent of the IMU that performs image analysis and alerts a user if there is insufficient coupling between the scanner and the body, wherein the system is configured to issue instructions to an operator of the system that enable scans to be performed by persons untrained in ultrasound scanning, including the patient themselves, and wherein when a scan is performed by the untrained operator, images produced by the scan are transmitted to a remote location for analysis by a medical professional.

2. The system of claim 1 , configured to allow two-way communication between the operator and a remote individual or unmonitored system.

3. The system of claim 2 , wherein the unmonitored system comprises an automatic image analysis circuit.

4. The system of claim 2 , wherein the two-way communication is selected from audio, visual, and video communication, and combinations thereof.

5. 3. The system of claim 2, wherein when the scan is performed by an untrained operator, two-way video communication is enabled between the operator and the medical professional, allowing the operator and the medical professional to see each other while the operator is performing the scanning procedure to assist the medical professional in interpreting the images and providing advice if necessary.

6. 3. The system of claim 2, wherein the system is configured such that the output of the system is transmitted in real time or immediately after the image is acquired to a remote medical professional and / or directly to an unsupervised system.

7. The system of claim 1 , configured to overlay an image of the scanner onto the ultrasound scan to assist a medical professional in interpreting the image.

8. 10. The system of claim 1, comprising components within or associated with a housing, the components including: i) an ultrasound probe head; ii) the at least one IMU including a three-axis accelerometer and a three-axis gyroscope; iii) electronic components for wired or wireless communication with a remote terminal; and iv) an internal or external power source.

9. 10. The system of claim 8, further comprising as additional system components: v) an Analog Front End (AFE) for transmitting and receiving ultrasound signals by using electronic components; vi) a processor including software; vii) a user interface having a display screen and means for accepting user instructions; and viii) at least one memory device for storing data and images processed by the software in the processor.

10. 10. The system of claim 9, further comprising: ix) a remote terminal; x) at least one additional IMU; xi) at least one magnetometer; xii) at least one pressure sensor; and xiii) at least one of a speaker and a microphone for communicating with a remote healthcare provider.

11. 10. The system of claim 9, wherein all of the other components v)-viii) are contained within a remote terminal connected to the scanner via a wired or wireless communication link.

12. 10. The system of claim 9, wherein some of the other components v) to viii) are contained within the scanner, and the remaining components are located in a remote terminal connected to the scanner via a wired or wireless communication link.

13. The system of claim 12 , wherein the remote terminal comprises a display, the IMU, and the processor.

14. 10. The system of claim 9, wherein the software is configured to perform at least one of: generating ultrasound images; analyzing the data; determining which images are of sufficient quality to be displayed on the display screen; discarding low-quality images; instructing the operator to hold the housing of the scanner in a predetermined manner; calculating the location and orientation of the scanner; determining whether the scanner is being held so that sufficient pressure is exerted on the skin to produce images of sufficient quality; and, effectively, providing instructions on how to properly move the scanner to obtain satisfactory results.

15. 15. The system of claim 14, wherein instructions to the operator generated by the software are provided visually on the display screen or audibly through a speaker.

16. 15. The system of claim 14, wherein instructions to the operator are provided visually on the display screen or audibly through a speaker by a trained medical professional located at a remote terminal.

17. 15. The system of claim 14, wherein if the processor determines that sufficient pressure is not being applied to the skin during scanning, instructions to increase the pressure are issued to the operator either visually on the display screen and / or audibly through a speaker.

18. The processor: Measuring the variance of image brightness across several regions of interest within the image and determining that the variance is less than a threshold.

18. The system of claim 17, wherein the system determines that insufficient pressure is being exerted on the skin by:

19. 10. The system of claim 1, comprising an electronic communication component selected from one or more of USB, Lightning, fiber optic, Wi-Fi, UWB, Bluetooth, and IR.

20. The system of claim 1 , comprising a component independent of the IMU that is adapted to alert a user if the scanning rate is too high.

Images