IL310480A - Method and system for performing retroactive mod-m and bpp - Google Patents

Description

45306/22 METHOD AND SYSTEM FOR RETROACTIVE M-MODE and BPP Field of the Invention The present invention relates to a method for performing fetal heartbeat measurements using pre-recorded data, particularly data recorded by an unskilled user, and their use in performing BPP and mBPP.

Background of the Invention A biophysical profile (BPP) test measures the fetus's health during pregnancy. A BPP test usually includes a non-stress test with electronic fetal heart monitoring (cardiotocography (CTG)) and fetal ultrasound imaging.

Fetal heart monitoring tracks the heart rate of the fetus during the pregnancy. This helps healthcare professionals (HCPs) assess the fetus's condition and detect early signs of distress. The fetal heart rate and the mother's contractions are monitored to see how the fetus responds. Two types of monitoring—external or internal—can be used. Instruments that detect fetal heartbeats are placed around the pregnant woman's abdomen for external monitoring. An example is a belt with ultrasonic piezo or similar transducers or ECG electrodes. For internal monitoring, electrodes that measure fetal heartbeats are connected to the fetus's scalp.

Using ultrasound imaging, the BPP assesses the fetus' heart rate, muscle tone, movement, breathing, and amniotic fluid. A health practitioner may do it in the third trimester or earlier for high-risk pregnancies or if there are concerns about the fetus’ health, decreased fetal movement, fetal growth problems, or if the pregnancy goes past 42 weeks. 45306/22 The BPP score The biophysical profile combines two tests to check the fetus's overall health: a nonstress test and an ultrasound.

The nonstress test checks the fetus’ heart rate and contractions. Devices are used to monitor the fetus’ movements and heart rate. The test evaluates fetal health and determines if the fetus is at risk for complications. The presence of fetal heart rate acceleration or deceleration is critical, and the test follows a systematic approach for interpretation. It does not hold predictive value and only indicates fetal hypoxemia at the time of the test. An example of guidelines for this test can be found at "Maternity - Fetal heart rate monitoring, GL2018_025, Ministry of Health, Public Health System, NSW, Australia" or at guidelines from the ACOG (American College of Gynecology), USA.

The biophysical profile test [National Library of Medicine, National Center for Biotechnology Information, Ultrasound Biophysical Profile, January 2022] evaluates fetal breathing, movement, tone, and amniotic fluid volume. Each area is given a score of 0 or 2, with a total score ranging from 0 to 10. A score of 8 to 10 is reassuring, 4 to 6 may require further testing or delivery, and a score of 0 or 2 almost always leads to immediate delivery. The test can help Health Care Professionals (HCP) decide if early delivery or medication is necessary.

The modified biophysical profile - mBPP A modified biophysical profile is a prenatal test that combines a nonstress test with an imaging ultrasound to measure amniotic fluid levels. It can be just as valuable as a full BPP.

Low levels of amniotic fluid may indicate an issue with the placenta. There are several 45306/22 methods of mBPP, including the rBPP, which has shown a high correlation to the classic BPP in clinical trials [Nasrin Soufizadeh et al., 2019].

ACOG recommends that the mBPP or BPP may also be used for antepartum fetal surveillance in pregnancies at increased risk for bad perinatal outcomes including, but not limited to, pregnancies complicated by hypertension, preeclampsia, pregestational diabetes, poorly controlled or medically treated gestational diabetes, poorly controlled hyperthyroidism, chronic renal disease, systemic lupus erythematosus, antiphospholipid syndrome, hemoglobinopathy (sickle cell disease), maternal cyanotic heart disease, moderate or severe asthma during pregnancy, isoimmunization, oligohydramnios, unexplained or recurrent risk for stillbirth, fetal growth restriction, and late-term pregnancy at or beyond 41 0/7 weeks, as described in several professional publications [2-5].

The Society of Obstetricians and Gynaecologists of Canada (SOGC) suggests antenatal fetal surveillance may also be beneficial in pregnancies complicated by preterm premature rupture of membranes, chronic (stable abruption), vaginal bleeding, abnormal maternal serum screening in the absence of confirmed fetal anomaly, motor vehicle accident during pregnancy, morbid obesity, advanced maternal age, assisted reproductive technologies, multiple pregnancy, polyhydramnios, and preterm labor [Liston R et al.].

Amniotic Fluid Volume is measured as the vertical measurement, in centimeters, of the single deepest pocket of amniotic fluid with a transverse measurement of 1 cm or wider without fetal small parts or umbilical cord [Chamberlain PF et al.]. 45306/22 A measurement is defined as "Reactive" if two or more fetal heart rate accelerations that peak (but do not necessarily remain) at least 15 beats per minute above the baseline and last at least 15 seconds from baseline to baseline during 20 minutes of observation, and "Nonreactive" if less than two accelerations of fetal heart rate as described above are seen after 40 minutes of observation [Practice Bulletin No. 145].

A score of 10 out of 10 points or 8 out of 10 points with normal fluid is considered normal. A score of 6 points is considered equivocal, and a score of 4 or less is abnormal. A score of less than 8 points indicates that the fetus may not be receiving enough oxygen. However, decreased biophysical activities may also be seen for a brief time in the preterm fetus after treatment with ether betamethasone or dexamethasone given to enhance fetal lung maturity, as described in several publications [9 – 11].

Other nonexclusive methods to calculate the FHR without a belt Except for the classic DOPETONE (i.e., non-imaging Doppler signal to measure the heartbeat), new methods have been introduced to measure fetal heart rate (FHR) without using a belt. These methods include 2D speckle tracking, which automatically calculates the FHR using a pattern-matching method. This technique uses myocardial deformation imaging to assess cardiac function and has been validated in several trials. Advanced ultrasound systems such as Hitachi's AutoFHR, Toshiba's Artida system, and General Electric's Voluson E10 BT19 Ultrasound System offer these tools, but they are expensive and typically used in professional healthcare settings.

It should be emphasized that all the above methods must be performed by specialized healthcare professionals, typically in a clinical environment and with expensive equipment. 45306/22 Before the present invention, no means have been provided to allow the determination of a fetal heartbeat or an estimate of a BPP or mBPP based on data provided by the patient herself, who acquired it outside such a specialized professional environment.

B-mode and M-mode scans Ultrasound equipment uses B-mode imaging to create a two-dimensional image of organs and tissues. An M-mode of operation available in sophisticated Ultrasound equipment provides a high time resolution view of the fetal heart. Except in specific cases, Doppler measurements are not used due to the ALARA rule, AIUM (American Institute of Ultrasound in Medicine), and other societies' guidelines in each country. Doppler sonography is a technique that uses reflected sound waves to measure movements such as blood flow and heartbeat. In cases where the Doppler technique is used, usually, a high-risk pregnancy is involved. In some cases, Doppler imaging can predict fetal distress earlier than BPP [Farzad Afzali]. Doppler ultrasound scans can be used to determine the speed of the blood flow and its direction. This information can be helpful in determining if fetal growth is normal, whether the tissues are supplied with enough blood and nutrients, and in discovering cases when the fetus is in distress. Again, the scan must be performed by specialized healthcare professionals, typically in a clinical environment and with expensive equipment.

Nowadays, home apparatuses exist for self-scanning at home to generate ultrasound images, such as the Pulsenmore ES device manufactured by the applicant hereof (https://pulsenmore.com/prenatal). When the patient is scanning herself in a non-clinical environment, such as at home using an ultrasound system, one should understand that a lay user is not familiar with all the terms of BPP, Doppler, scans, etc. Hence, the system should allow the HCP to obtain this information remotely or offline. 45306/22 From the above, it is apparent that allowing more convenient and easy ways to determine, for example, a fetal heart rate through the action of an unskilled operator such as the patient herself, is of paramount importance in maintaining fetal health and avoiding adverse events that can be prevented if a BPP or mBPP is readily available.

It is an object of the present invention to provide a method and system for performing off- line fetal heartbeat measurements employing pre-recorded ultrasound images, regardless of the skill of the person who recorded them.

It is another object of the invention to perform heartbeat measurements by permitting the performance of M-mode measurements on previously acquired ultrasound images.

It is still a further object of the invention to allow the measurement of fetal heartbeat using pre-recorded Doppler data.

It is yet another object of the invention to allow using pre-recorded ultrasound data to perform additional measurements, such as amniotic fluid content and fetal movement.

It is still another object of the invention to allow a health care professional to derive the heart rate of a fetus from previously acquired ultrasound images, specifically if the measured organ is moving or the scanner is moving during scanning, which often occurs when the patient takes a self-scan or an unskilled user takes a scan. 45306/22 Another object of the invention is to provide a method and system by which a determination of a fetal heart rate can be obtained from ultrasound images acquired by an unskilled user outside of a medical environment, such as self-scans obtained by a pregnant woman in the privacy of her home.

It is still another object of the invention to provide a method and system to generate a BPP or an mBPP score either offline or online including but not limited to, by incorporating the M-mode or Doppler measurements during remote scans (telehealth) while the patient is not in a clinical environment.

Other objects and advantages of the invention will become apparent as the description proceeds.

Summary of the Invention The invention relates to a method for obtaining an approximate measurement of a fetus’ heartbeat, comprising: i. Recording by a user a data stream of ultrasound images or Doppler measurements using a scanning device adapted to be operated by an unskilled user; ii. Storing the recorded data stream; and iii. At a location separate from the scanning device, analyzing the stored stream to derive an estimate of the fetal heartbeat.

In one embodiment of the invention, the data stream is stored at a location remote from the recording device. In some embodiments, storing of the data stream to a remote location is performed during the scanning operation, while in others, the data stream is first stored in a 45306/22 memory provided in the scanning device or in a device in communication therewith and then is transmitted to a remote location for analysis. The device that is in communication with the scanning device can communicate via various channels known per se, such as Bluetooth or WiFi.

In one particular embodiment, the method for obtaining an approximate measurement of a fetus’ heartbeat from ultrasound images comprises: a) displaying a video stream of acquired ultrasound images on a display associated with image-processing apparatus; b) locating the fetus’ heart on said video stream; c) selecting on said display a beam from the plurality of beams that generate the ultrasound image, which selected beam passes through the fetus’ heart; d) creating a periodic view of the fetus’ heartbeat by generating an enlarged, time-lapse view of the data captured by the portion of the selected beam that passes through the heart; and e) determining the heart rate by selecting on said time-lapse view at least two locations spatially apart by one period of the sinusoidal heartbeat signal, determining the time difference between them, and normalizing for a predetermined period of time.

The at least two locations spatially apart by one period of the sinusoidal heartbeat signal can be, for example, two adjacent maxima or minima. In a particular embodiment, the period of time during which the time difference between the at least two adjacent maxima in the heartbeat is normalized is at least one minute. 45306/22 The invention further allows compensating for the motion of the area of interest of the image using a tracking process and repositioning the analyzed beam to the new location. In some embodiments, data collected before repositioning the analyzed beam is used together with data collected on the repositioned beam.

In embodiments of the invention, the data stream consists of Doppler measurements and analyzing includes locating a beam that elicits a Doppler signal and extracting heartbeat measurements therefrom. The Doppler equipment is, in some embodiments, a pulsed wave Doppler device, and the Doppler shift is calculated using the FOI, BOI, and POI by reconstructing the stored scan RBI. In some embodiments, reconstructing the Doppler image is performed in the cloud using cloud computing.

The invention is also directed to apparatus for obtaining an approximate measurement of a fetus’ heartbeat from ultrasound images, comprising: i) display means adapted to display a video stream of acquired ultrasound images; ii) selection component adapted to select a single beam from among the plurality of beams that compose the ultrasound image; iii) image-generation apparatus suitable to generate an enlarged, time-lapse view of the data captured by a portion of said beam; and iv) measurement components adapted to measure the time difference between locations spatially apart by one period of the sinusoidal images representing heartbeats.

In some embodiments of the apparatus, the stream of ultrasound images is generated in real time. The ultrasound image stream can be generated in situ and can be pre-recorded. 45306/22 Apparatus according to the invention may further comprise image processing components, e.g., such that is adapted to perform image tracking.

In a further aspect, the invention is directed to a method for performing BPP or mBPP using ultrasound data acquired by an unskilled user, comprising performing a heartbeat measurement according to claim 1 and further determining additional parameters, such as fetus’ movement and amniotic fluid volume, by analyzing images reconstructed using previously stored raw beam data.

Yet another aspect of the invention relates to a system for obtaining an approximate measurement of a fetus’ heartbeat, comprising: i. Apparatus adapted to record by a user a data stream of ultrasound images or Doppler measurements using a scanning device adapted to be operated by an unskilled user; ii. A remote storage for storing the recorded data stream; and iii. Cloud computing equipment adapted to analyze the stored stream to derive an estimate of the fetal heartbeat.

Embodiments of the system comprise a communication channel for transmitting a data stream from the scanning device to a location remote from that of the recording device.

The cloud computing equipment includes, in some embodiments of the system, a display for displaying a video stream of acquired ultrasound images and image-processing apparatus adapted to: 45306/22 a) locate the fetus’ heart on said video stream; b) select on said display a beam from the plurality of beams that generate the ultrasound image, which selected beam passes through the fetus’ heart; c) create a periodic view of the fetus’ heartbeat by generating an enlarged, time-lapse view of the data captured by the portion of the selected beam that passes through the heart; and d) select on said time-lapse view at least two locations spatially apart by one period of the sinusoidal heartbeat signal, determining the time difference between them and normalizing for a predetermined period of time, thereby determining the heart rate.

Also encompassed by the invention is a system for obtaining a blood velocity measurement utilizing Doppler imaging, comprising: i. Apparatus adapted to record by a user a data stream of ultrasound images or Doppler measurements using a scanning device adapted to be operated by an unskilled user; ii. A remote storage for storing the recorded data stream; and iii. Cloud computing equipment or HCP Interpreter device adapted to analyze the stored stream to derive an estimate of the blood velocity.

The system can be further adapted to color blood vessels in different colors to differentiate between blood flow coming toward the transducer and blood flow moving away from the transducer.

As will be apparent to the skilled person, the invention permits the performance of a "retroactive M-mode analysis" for measuring the fetal heartbeat in an ultrasound scan, even when the scanner is moving relatively to the organ or tissue or the scanner is fixed, however 45306/22 the organ is moving. The invention can also be implemented during remote real-time measurements over a smartphone, Wi-Fi, or cellular network.

M-mode ultrasound is a common ultrasound imaging modality that targets the extraction of a motion signal from a series of ultrasound frames. One of the use cases for M-mode is to analyze the heart rate by tracking the cardiac cycle of the heart contraction and relaxation.

In the clinic, an M-mode is performed by intersecting the heart with a line corresponding with one of the ultrasound beams, which is drawn on the screen. The M-mode image displays the signal along this line over time while the ultrasound scan is being taken, generating a cardiac cycle image that can be assessed by health professionals.

When patients (lay users) perform scans at home, using a home ultrasound device such as, for instance, that described in US Patent No. 10,610,194, the signal across each ultrasound beam is stored and is then transmitted to the cloud. As will be further explained hereinafter, this enables the generation of the M-mode image after the fact, and clinicians can evaluate the cardiac activity retroactively on a pre-recorded scan despite it having been acquired by an unskilled patient or helper. The same is true, mutatis mutandis, for Doppler.

One important aspect of this invention is the ability to handle the motion of the heart location in the frame. Typically, such motion is caused by the patient moving the probe during the scan, which does not typically happen when an expert healthcare professional performs the scan in a clinical environment using clinic-standard equipment. To address this problem, the Retroactive M-mode algorithm tracks the heart location on the B-mode image, and when the heart is no longer intersecting with a beam, a new intersecting beam is 45306/22 selected, and the signal along this beam is drawn into the M-mode image. The same applies mutatis mutandis when a Doppler mode is used.

In a further aspect, the invention is directed to apparatus for performing mBPP, comprising: a) a housing adapted to hold a scanning assembly, said housing being provided with an opening that allows an ultrasound transducer to come into contact with a patient’s skin; b) fastening components suitable to maintain said housing firmly positioned on a patient’s skin; and c) a positioning component adapted to position the said transducer and change its orientation relative to the patient’s body.

In a particular embodiment of the invention, the fastening component comprises a belt, and in a further specific embodiment, it additionally comprises an elastic segment. In some embodiments, the positioning component is a ball socket joint adapted to fit in the socket provided in said housing.

In yet another aspect, the invention encompasses a system for performing mBPP, comprising the above-detailed apparatus for performing mBPP and a device provided with an ultrasound transducer, which is adapted to acquire ultrasound data.

All the above and other characteristics and advantages of the invention will be further understood through the following illustrative description of embodiments thereof.

Brief Description of the Figures 45306/22 In the figures: Fig. 1 shows a dashboard for a healthcare professional showing five different streams of ultrasound scans from which the healthcare professional can choose; Fig. 2 shows the frame of interest (FOI) that has been selected for further operations; Figs. 3 illustrates the selection of a single beam of interest (BOI) from which data is to be extracted; Fig. 4 shows the selection of the point of interest (POI) along the BOI; Figs. 5 – 8 show various manipulations on the bottom screen window where the cardiac cycle derived from the M-mode is shown: Fig. 5: showing the M-mode cardiac cycle; Fig. 6 Controlling the M-mode image contrast; Fig. 7 Controlling the M-mode image time window; and Fig. 8 Controlling the M-mode image depth window.

Fig. 9 illustrates how, during the analysis, the cardiac cycle is marked; Fig. 10 illustrates the M-mode motion compensation; Fig. 11 illustrates the operation of a Doppler probe, with one element of the probe acting as a transmitter and another element as a receiver; Fig. 12 is a schematic illustration of CW, PW, and multi-range-gated PW Doppler techniques; Fig. 13 schematically illustrates a standard implementation; Fig. 14 is an illustrative view of the result of the heart rate detection using Doppler; Fig. 15 illustrates the image obtained using a pulsed wave Doppler device; Fig. 16 is a perspective view of an embodiment of a novel apparatus adapted to perform the invention; Fig. 17 is a perspective view taken from below of the apparatus of Fig. 16; 45306/22 Fig. 18 is an exploded view of a specific embodiment of an apparatus of the invention; and Fig. 19 is a front view of the apparatus of Fig. 16, as is seen by the patient.

Detailed Description of the Invention The system of the invention contains the storage of the entire stream of ultrasound images, acquired by the ultrasound scanner or by the Doppler device, which will be discussed later on. Although currently existing ultrasound devices in the market employ an M-mode image, this is only a real-time function, and they do not support this functionality retroactively after the scan that was already done.

Contrary to the prior art, the invention allows the healthcare professional to assess the cardiac cycle on ultrasound images from a completed scan performed in the past by a patient or by another individual, skilled or not. In other words, according to the invention, it is made possible to reconstruct the selected beam signal, as it was acquired during the scan, to produce the M-mode image retroactively. This reconstruction is feasible since this information is captured and saved during the scan into a special structure representing the raw beam information ("RBI") and then made available for offline analysis. Each RBI file includes a series of Z vector arrays (Z depends on the frame rate of the device and the length of scan recording – e.g., 1200 arrays for 60 seconds of scan at 20 frames per second). Each vector array includes N vectors representing the ultrasound beams (N is typically 128 for a commercial device, such as the Pulsenmore ES device (https://pulsenmore.com/prenatal/), and is determined by the beam forming functionality). 45306/22 Each vector (beam) includes M elements (for instance, 1008 elements per vector, where element 0 represents the closest distance from the transducer and element 1008 represents the farthest distance from the transducer). Each element is represented by a digital value (for instance, using a byte structure, where 0 represents no signal and 255 represents the highest possible signal received). A single element represents the signal strength on a specific beam at a particular time, and by depicting all elements as pixels for a specific beam over time, we get the M-mode image. This is a typical M-mode structure for a specific BOI N, where pixels (representing depth) are drawn from top to bottom (from P 1 to P M), and frames (representing time) are drawn from left to right, across frames (from F 1 to F Z), [F 1 B N P 1] [F 2 B N P 1] … [F Z B N P 1] [F 1 B N P 2] [F 2 B N P 2] … [F Z B N P 2] ….

[F 1 B N P M] [F 2 B N P M] … [F Z B N P M] Contrary to the prior art, the beam on which the M-mode analysis is done can also be selected retroactively. This means that if the heart location changes over time, or if there is a need to assess other types of movements, the user can select a different BOI and generate a time series M-mode image along this newly selected beam.

According to the invention, the system operator, who typically but not necessarily will be a healthcare professional, can select the BOI and produce different M-mode images for different beams selected. Moreover, since the analysis is done retroactively, the M-mode time series includes information collected for past and future frames relative to the current frame where the BOI is selected. 45306/22 As will be apparent to the skilled person, the invention opens up a slew of opportunities for the system user to analyze different portions of the ultrasound as if they were taken in M- mode, even though they were not. This allows the user to run through the stream of ultrasound images forward and backward at will and obtain the best possible information that can be extracted from said stream of images.

A system according to an illustrative embodiment of the invention, has the following characteristics: 1. App function that collects and stores the RBI structure during a scan and uploads it to the cloud when the scan completes; 2. A user interface to view the scan clip and play back the scan clips as a B-mode image series; 3. A user interface for generating the M-mode image by selecting FOI, BOI, and POI for a given scan and clip; and 4. Cloud function that generates the M-mode image for a given scan, clip, FOI, BOI, and POI.

According to an alternative embodiment of the invention, instead of performing steps 1- above, the RBI structure is sent directly to the reader device (also referred to as "Interpreter"), which can be, for instance, a smart device or a computer, where the data interpretation is carried out.

The following examples, provided with reference to the figures, will further illustrate the features and advantages of the invention. This example makes reference to the Pulsenmore system and to the use of the aforementioned Pulsenmore ES device, it being understood 45306/22 that the same is applicable mutatis mutandis to ultrasound image streams acquired through different devices.

Fig. 1 shows the clinician dashboard user interface where a user, logged into the Pulsenmore system, can watch multiple ultrasound scan video clips. The actual structure of the dashboard is not essential to the invention, and the one shown in the figure is provided merely for illustrative purposes. For this illustration, the user selects clip 3 and performs an M-mode measurement. The user can generate a retroactive M-mode for each scan by clicking the FHR (fetal heart rate) button at the top of each clip.

Before starting the FHR measurement, the user needs to find the heart location in the clip.

When the heart is visible, the user pauses the clip and goes back and forth between frames, using the arrow buttons shown in Fig. 2 to find the frame-of-interest (FOI), which is a frame that shows a good image of the heart.

On the FOI, the user selects the beam of interest ("BOI") by intersecting a line with the heart location. This line is used to specify the beam index used to generate the M-mode image by plotting the ultrasound signal along this line over time, as shown in Fig. 3. The coordinates of the intersecting line define the actual BOI since the lines that can be drawn can only exist in overlap with the actual beams that form the image.

On the BOI, the user clicks to mark the point-of-interest ("POI"), which is the heart location, when measuring fetal heart rate using M-mode. This location also defines the vertical center on the M-mode image, which is the POI depth in the picture, as shown in Fig.4. This sets the FOI, BOI, and POI used for generating the M-mode image. 45306/22 As will be apparent to the skilled person, detecting FOI, BOI, and POI can be done automatically using image processing designed to detect the heart location in the scan’s clip.

The manual procedure is explained here to better show the process, but any automatic detection is also meant to be covered by the invention.

The Pulsenmore system uses the FOI, BOI, and POI to generate the M-mode image by invoking a cloud function that reconstructs this image using the scan RBI stored in the cloud.

This reconstruction process will be apparent to the skilled person and, therefore, is not described herein in detail for the sake of brevity. Once this image is ready, it is shown below the B-mode image, as shown in Fig. 5, demonstrating the cardiac cycle that enables objective heart rate measurements.

The user can use various controls to enhance the visibility of the cardiac cycle, changing image contrast and zooming in/out along the depth and time axes, as illustrated in Figures 6- 8. Once the cardiac cycle is clearly seen, the user marks two or three points (or more, if desired, although it is not needed), as shown in Fig. 9, to enable the automatic measurement of the fetal heart rate.

Motion Compensation Motion compensation is very important in a home-use scenario. In the home scenario, the patient (or someone assisting the patient) holds the ultrasound device in her hand. When the patient moves it to capture scan information, the heart location changes across consecutive frames. The motion compensation algorithm tracks the heart location in the B- mode image series, as is shown in Fig. 10, and allows the automatic repositioning of the BOI 45306/22 and POI in consecutive frames. Tracking methods are well known in the art and, therefore, are not described herein in detail. A box defining the area of interest (AOI) around the POI is tracked across consecutive frames using pattern-matching algorithms, and the box center defines the calculated BOI and POI in different frames. The M-mode image constructed using motion compensation aggregates the signal along the calculated BOIs instead of just using the original BOI as a fixed index for this reconstruction and enables the generation of M- mode images from scans performed by lay users in the comfort of their homes.

Using B [Fx] to describe a calculated beam index in frame X, the M-mode image reconstructed using motion compensation is: [F 1 B [F1] P 1] [F 2 B [F2] P 1] … [F Z B [FZ] P 1] [F 1 B [F1] P 2] [F 2 B [F2] P 2] … [F Z B [FZ] P 2] ….

[F 1 B [F1] P M] [F 2 B [F2] P M] … [F Z B [FZ] P M] In contrast to the B-mode image reconstructed without motion compensation: [F 1 B N P 1] [F 2 B N P 1] … [F Z B N P 1] [F 1 B N P 2] [F 2 B N P 2] … [F Z B N P 2] ….

[F 1 B N P M] [F 2 B N P M] … [F Z B N P M] From the above description of this illustrative embodiment, it is now clear that the invention allows performing what could be termed a "retroactive M-mode" needed to generate a biophysical profile of a fetus with high precision and based on all the data acquired during the ultrasound scan, as opposed to the M-mode available to healthcare professionals today, which does not allow changing the selected beam to obtain better and more precise results during the examination of the ultrasound images. This novel method and system open new 45306/22 avenues for a better and easier determination of a fetus’ BPP that were not available before the invention.

The invention can also be exploited when performing a Doppler measurement. The entire stream of ultrasound measurements performed by an unskilled (or, of course, also if the user is skilled) is saved and post-analyzed. As will be apparent to the skilled person, the Doppler effect will only exist where the beam crossed the fetus' heart. Accordingly, the saved raw data can be analyzed to locate the location in the data stream where the maximal Doppler effect is observed, and the fetal heartbeat is then extracted using methods known in the art.

When Doppler is involved, the Pulsenmore system uses the FOI, BOI, and POI to calculate the Doppler shift by invoking a cloud function that reconstructs this image using the scan RBI stored in the cloud. This reconstruction process will be apparent to the skilled person and, therefore, is not described herein in detail for the sake of brevity. An example of a signals mixer implemented in hardware can be found in many AFE (Analog Front End) chips for ultrasound, for example, the Texas Instruments 58XX family. However, according to the invention, the information that is stored in raw beams serves now to generate the I-Q channels that are fed to a software mixer and to extract the Doppler shift from which the heart rate or velocity of blood flow is derived. Moreover, usually in hardware AFE semiconductors (integrated circuit), the I-Q mixer is used for several channels. This is due to the dimension of the chip and the cost of implementing a mixer. In one embodiment of the present invention, the mixer is implemented in the cloud or in the reader smart device or computer (i.e., the Interpreter) using at least one mixer per channel implemented in software. Hence, for a 64-element ultrasound probe, 64 software mixers are provided. It is 45306/22 also possible to store the transmitted signal with known frequency, correlate the reflected (the received signal), extract the Doppler shift in frequency, and derive, for example, the velocity). If a 128 or more elements transducer is considered, the same applies to the 128 or more elements, thus generating 128 cloud mixers or in the reader smart device or computer, or more as the case might be.

There are many options to estimate the fetal heart rate. Hereinafter, reference is made to the standard one, with particular reference to the illustration of Fig. 12, which is a schematic illustration of CW, PW, and multi-range-gated PW Doppler techniques. These estimations are performed in the cloud or the HCP reading device, all from the raw beams uploaded by the patient's device.

A CW Doppler contains two piezoelectric elements: one that continuously emits ultrasound waves while the other constantly detects ultrasound echoes from the tissue. The overlap field is the location where Doppler signals may be detected, the 'sample volume' (SV). The sample volume is smaller in PW Doppler, and the SV depth may be selected remotely or can be changed per the raw beams that exist in the file that was sent from the scanner to the cloud or the HCP device (i.e., the aforementioned Interpreter). In multi-range-gated PW Doppler, the SV is sectioned, enabling the identification of various Doppler spectra through the cross-section of the vessel.

Fig. 13 schematically illustrates a standard implementation where the Doppler-measured signal is multiplied in an IQ scheme, the envelope is detected, and the fetal heart rate is estimated. Similar results can be implemented in the HCP remote device or in the cloud, a method that detects the positive and negative signals amplitude (directional signals) instead 45306/22 of the envelope. An illustrative view of the result of the heart rate detection using Doppler is shown in Fig. 14.

In a pulsed wave Doppler, the same elements are used for transmitting and receiving, and brief pulses of ultrasound energy are emitted. Range gating is used to only accept echoes returning from a specific depth. Duplex involves Doppler imaging overlayed over B-mode imaging. Fig. 15 illustrates the image obtained using a pulsed wave Doppler device.

There are three types of pulsed wave Doppler used in ultrasound machines: Color, Power, Spectral. In color Doppler, the sampling volume is set, and the mean and variance of the velocity of the moving structures are calculated in the cloud or the HCP remote device. Power Doppler images map the amplitude of the Doppler signal only without any indication of the velocity. All movement, regardless of phase, contributes to the amplitude. This means that the power Doppler emphasizes the quantity of blood flow.

Hence, for example, it is possible to visualize blood flow in the belly cord and determine if there is a problem when there is very low flow. A Spectral Doppler shows the range of Doppler frequencies returned over time and displayed in a sonogram. Differences in vessel wall resistance produce different spectral traces.

In embodiments of the invention, the lay user, i.e., the patient, performs a scan while Doppler imaging is activated. Hence, measurements of the blood flow and heartbeat exist in the data file of the patient device, which is uploaded to the cloud or uploaded to the reader (HCP) device and extracted from the image (the raw beams). It follows that if CW (Continues Wave) is used, for example, through the IQ (in phase and quadrature respectively) scheme that is well known in the art. It is possible to use PW (Pulse Wave) utilizing software and 45306/22 processing the selected beams. Moreover, if the Doppler measurement is applied remotely, information regarding the raw beams is stored in the file, generating I and Q channels in the cloud or sent for processing in the remote device of the HCP. One can use a signals mixer, hence it is possible to extract the frequency shift (Doppler) and to calculate the heartbeat, all in software instead of hardware (i.e., instead of an integrated circuit) in the cloud or in the remote device of the HCP. In addition, to measure the heartbeat, the HCP can remotely apply a heart rate measurement using one element from the probe to transmit and another to receive, and the calculation of the Doppler can be conducted either in the cloud or in the HCP Interpreter device. Hence, the invention enables the HCP to review scan clips where Doppler is applied and to review information that is not real-time but was scanned by the lay user at a nonclinical setup.

Two mandatory parameters must be monitored when Doppler is applied: Mechanical index and Temperature index (Mi and Ti, respectively). Therefore, during remote BPP or through a Doppler imaging scan, the HCP sets the system parameters, applies Doppler or M-mode, and measures the heartbeat (or when appropriate Doppler is used, it can also visualize the blood flow, for example, from the umbilical cord). Mi and Ti can be presented with the image. In the case of Offline M-Mode analysis, i.e., the patient scanned herself and sent the scan clip to HCP for reading and interpretation, these parameters are extracted from the beams (raw data) that generated the image.

An illustrative embodiment of the apparatus for facilitating self-collection of BPP data will now be described. The apparatus may use, for example, a 2D phase array transducer (e.g., 32 x 16 elements or other combination) or a 64 X 1 elements phase array for MBPP ultrasound scanning. The phase array transducer is contained in an apparatus fastened to 45306/22 the patient’s belly. In the illustrative embodiment described below, the fastening is performed using a belt with an elastic section, but it can be fastened by any other means known per se in the art.

The apparatus is devised such that the transducer can make two-dimensional scans, i.e., a rectangular coverage of the fetus, and collect its MBPP vital signs. As will be appreciated by the skilled person, the time required for collecting significant vital signs is long, of the order of 20 minutes, and it is impractical to require the patient to hold the transducer still for that length of time while collecting data. The apparatus, according to the invention, overcomes the problems and avoids the related discomfort to the patient.

Turning now to Fig. 16, Numeral 160 generally indicates the device according to the invention, which is provided with structure 161 that holds the transducer, which is incorporated in device 164, which will be further discussed below, and a hook and loop belt 162, a section of which consists of a rubber rope 163, the function of which will is discussed with reference to Fig 18. Fig 17 shows the bottom portion 170 of structure 161 With the opening 171 through which the transducer comes in contact with the patient’s skin.

Fig 18 is an exploded view of the device of Fig. 16. The basis 180 of device 161 is provided at its corners with four rope rollers 181, which allow the fine tightening or releasing of belt 162. Base 118 is provided with a socket 181 into which ball socket joint 183 fits. At the bottom of socket 181 there is provided hole 171 through which the transducer can reach the patient's skin. The bottom of socket 183 is also open (not shown) to allow the passage of the transducer. 45306/22 Device 164, which comprises the transducer, fits into the ball socket joint 183. For the convenience of fitting, this particular embodiment also provides a sponge housing 184, which fits into the upper opening of ball socket joint 183, but as will be appreciated by the skilled person, this could be built-in bucket socket joint 183 and not provided separately.

Device 164 can be any suitable device adapted to scan and deliver ultrasound scan data to a further device or location for further processing and can be, for instance, the Pulsenmore ES device manufactured by Pulsenmore Ltd (https://pulsenmore.com/prenatal/) or a device as described in WO 2021/220263.

Fig. 19 is a front view of assembly 160. Device 164 is adapted to house a smartphone to operate the transducer, record or transmit scan data, and perform other activities. In this particular embodiment, a connector 190 is provided, which is suitable, e.g., for Android devices, and an additional connector 191 can be provided for other types of smart devices, e.g., for IOS smartphones. Device 164 may also be in communication with smart devices via wireless connection, e.g., Bluetooth or Wi-Fi.

Although the invention was illustrated through an example of the measurement of fetal heartbeat, the retroactive M-mode of the invention can be exploited to analyze any other real-time changes that take place anywhere in the ultrasound scan, such as the visualization of regular lung movement.

All the above description of the method and system of the invention have been provided for the purpose of illustration and are not meant to limit the invention in any way. As will be apparent to the skilled person, different implementations of the method can be devised, 45306/22 using different image processing and data processing methods, all without exceeding the scope of the invention.

List of References: 1. Diagnostic Value of Rapid Biophysical Profile in Comparison to Biophysical Profile in Pregnant Women with Insulin-Dependent Diabetes Nasrin Soufizadeh, M.D., Fariba Farhadifar, M.D., Saghar Tamri, M.D., Sara Behafarid, M.D., Karim Sharifi, M.D., Sima Aslani, M.D., and Mobin Naqshbandi, M.D. J Family Reprod Health. 2019 Dec; 13(4): 209–213. 2. Antepartum fetal surveillance. Practice Bulletin No. 145. American College of Obstetricians and Gynecologists. Obstet Gynecol 2014;124:182–92PMID:24945455. 3. Asthma in pregnancy. ACOG Practice Bulletin No. 90. 4. American College of Obstetricians and Gynecologists. Obstet Gynecol 2008; 111:457–64.PMID: PMID:18238988.

. Management of late-term and post-term pregnancies. Practice Bulletin No. 146.

American College of Obstetricians and Gynecologists. Obstet Gynecol 2014;124:390– 6. PMID: PMID:25050770 . 6. Liston R, Sawchuck D, Young D; Society of Obstetrics and Gynaecologists of Canada; British Columbia Perinatal Health Program. J Obstet Gynaecol Can. 2007 Sep;29( Suppl 4):S3-56. Erratum in: J Obstet Gynaecol Can. 2007 Nov;29(11):909.

PMID:17845745 Available at: http://sogc.org. 7. Chamberlain PF, Manning FA, Morrison I, Harman CR, Lange IR. Ultrasound evaluation of amniotic fluid volume. I. The relationship of marginal and decreased amniotic fluid volume to perinatal outcome. Am J Obstet Gynecol 1984;150:245– 9.PMID:6385713. 45306/22 8. Antepartum fetal surveillance. Practice Bulletin No. 145. American College of Obstetricians and Gynecologists. Obstet Gynecol 2014;124:182–92PMID:24945455. 9. Rotmensch S, et al., The effect of betamethasone and dexamethasone on fetal heart rate patterns and biophysical activities, A prospective randomized trial. Acta Obstet Gynecol Scand. 1999 Jul;78(6):493-500. PMID: PMID:10376858.

. Antepartum fetal surveillance. Practice Bulletin No. 145. American College of Obstetricians and Gynecologists. Obstet Gynecol 2014;124:182–92PMID:24945455. 11. Fetal health surveillance: antepartum and intrapartum consensus guideline. Liston R, Sawchuck D, Young D; Society of Obstetrics and Gynaecologists of Canada; British Columbia Perinatal Health Program. J Obstet Gynaecol Can. 2007 Sep;29(9 Suppl 4):S3-56. Erratum in: J Obstet Gynaecol Can. 2007 Nov;29(11):909. PMID:178457 Available at: http://sogc.org/wp-content/uploads/2013/01/gui197CPG0709r.pdf 12. Biophysical Profile & Color Doppler Ultrasound in the High-Risk Pregnancy August 17, 2011, Farzad Afzali, MD.

Claims (29)

45306/22 - 29 - Claims

1. A method for obtaining an approximate measurement of a fetus’ heartbeat, comprising: iv. Recording by a user a data stream of ultrasound images or Doppler measurements using a scanning device adapted to be operated by an unskilled user; v. Storing the recorded data stream; and vi. At a location separate from the scanning device, analyzing the stored stream to derive an estimate of the fetal heartbeat.

2. A method according to claim 1, wherein the data stream is stored at a location remote from that of the recording device.

3. The method of claim 2, wherein storing of the data stream to a remote location is performed during the scanning operation.

4. The method of claim 2, wherein the data stream is first stored in a memory provided in the scanning device or in a device in communication therewith and then is transmitted to a remote location for analysis.

5. The method of claim 4, wherein the device in communication with the scanning device communicates via Bluetooth or WiFi.

6. A method according to claim 1, for obtaining an approximate measurement of a fetus’ heartbeat from ultrasound images, comprising: a) displaying a video stream of acquired ultrasound images on a display associated with image-processing apparatus; b) locating the fetus’ heart on said video stream; c) selecting on said display a beam from the plurality of beams that generate the ultrasound image, which selected beam passes through the fetus’ heart; 45306/22 - 30 - d) creating a periodic view of the fetus’ heartbeat by generating an enlarged, time-lapse view of the data captured by the portion of the selected beam that passes through the heart; and e) determining the heart rate by selecting on said time-lapse view at least two locations spatially apart by one period of the sinusoidal heartbeat signal, determining the time difference between them, and normalizing for a predetermined period of time.

7. The method of claim 6, wherein the at least two locations spatially apart by one period of the sinusoidal heartbeat signal are two adjacent maxima or minima. The method of claim 1, wherein the period of time during which the time difference between the at least two adjacent maxima in the heartbeat is normalized is at least one minute.

8. The method of claim 6, further comprising compensating for the motion of the area of interest of the image using a tracking process and repositioning the analyzed beam to the new location.

9. The method of claim 8, wherein data collected before repositioning the analyzed beam is used together with data collected on the repositioned beam.

10. The method of claim 1, wherein the data stream consists of Doppler measurements, and analyzing includes locating a beam that elicited a Doppler signal and extracting heartbeat measurements therefrom. 45306/22 - 31 -

11. The method of claim 10, wherein the Doppler equipment is a pulsed wave Doppler device.

12. The method of claim 10, wherein the Doppler shift is calculated using the FOI, BOI, and POI by reconstructing the stored scan RBI.

13. The method of claim 12, wherein reconstructing the Doppler image is performed in the cloud using cloud computing.

14. Apparatus for obtaining an approximate measurement of a fetus’ heartbeat from ultrasound images, comprising: i) display means adapted to display a video stream of acquired ultrasound images; ii) selection component adapted to select a single beam from among the plurality of beams that compose the ultrasound image; iii) image-generation apparatus suitable to generate an enlarged, time-lapse view of the data captured by a portion of said beam; and iv) measurement components adapted to measure the time difference between locations spatially apart by one period of the sinusoidal images representing heartbeats.

15. Apparatus, according to claim 14, wherein the ultrasound images stream is generated in real-time.

16. Apparatus, according to claim 14, wherein the ultrasound image stream is generated in situ. 45306/22 - 32 -

17. Apparatus, according to claim 14, wherein the ultrasound image stream is pre-recorded.

18. Apparatus according to claim 14, further comprising image processing components.

19. Apparatus according to claim 18, wherein the image processing component is adapted to perform image tracking.

20. A method for performing BPP or mBPP using ultrasound data acquired by an unskilled user, comprising performing a heartbeat measurement according to claim 1, and further determining additional parameters, such as fetus’ movement and amniotic fluid volume, by analyzing images reconstructed using previously stored raw beam data.

21. A system for obtaining an approximate measurement of a fetus’ heartbeat, comprising: iv. Apparatus adapted to record by a user a data stream of ultrasound images or Doppler measurements using a scanning device adapted to be operated by an unskilled user; v. A remote storage for storing the recorded data stream; and vi. Cloud computing equipment adapted to analyze the stored stream to derive an estimate of the fetal heartbeat.

22. The system of claim 21, comprising a communication channel for transmitting a data stream from the scanning device to a location remote from that of the recording device. 45306/22 - 33 - 23. The system of claim 21, wherein the cloud computing equipment includes a display for displaying a video stream of acquired ultrasound images and image-processing apparatus adapted to: a) locate the fetus’ heart on said video stream; b) select on said display a beam from the plurality of beams that generate the ultrasound image, which selected beam passes through the fetus’ heart; c) create a periodic view of the fetus’ heartbeat by generating an enlarged, time-lapse view of the data captured by the portion of the selected beam that passes through the heart; and d) select on said time-lapse view at least two locations spatially apart by one period of the sinusoidal heartbeat signal, determining the time difference between them, and normalizing for a predetermined period of time, thereby determining the heart rate.

23. A system for obtaining a blood velocity measurement utilizing Doppler imaging, comprising: iv. Apparatus adapted to record by a user a data stream of ultrasound images or Doppler measurements using a scanning device adapted to be operated by an unskilled user; v. A remote storage for storing the recorded data stream; and vi. Cloud computing equipment or HCP Interpreter device adapted to analyze the stored stream to derive an estimate of the blood velocity.

24. The system of claim 23, further adapted to color blood vessels in different colors to differentiate between blood flow coming toward the transducer and blood flow moving away from the transducer.

25. Apparatus for performing mBPP, comprising: 45306/22 - 34 - a) a housing adapted to hold a scanning assembly, said housing being provided with an opening that allows an ultrasound transducer to come into contact with a patient’s skin; b) fastening components suitable to maintain said housing firmly positioned on a patient’s skin; and c) a positioning component adapted to position the said transducer and change its orientation relative to the patient’s body.

26. Apparatus according to claim 25, wherein the fastening component comprises a belt.

27. Apparatus according to claim 26, wherein the fastening component further comprises an elastic segment.

28. Apparatus according to claim 25, wherein the positioning component is a ball socket joint adapted to fit in the socket provided in said housing.

29. A system for performing mBPP, comprising apparatus according to claim 25 and a device provided with an ultrasound transducer, which is adapted to acquire ultrasound data.