Temperature-controlled imaging phantom

Abstract

A method of determining performance characteristics of an ultrasound probe via a phantom includes controlling a temperature of an ambient environment of the phantom to a first temperature value and controlling a temperature of an interface between the phantom and the ultrasound probe to a second temperature value. The method includes, while the temperature of the ambient environment of the phantom is at the first temperature value, acquiring one or more ultrasound images via the ultrasound probe while maintaining the temperature of an interface between the phantom and the ultrasound probe at the second temperature value.

Description

Temperature-Controlled Imaging PhantomTECHNICAL FIELD

[0001] The disclosed implementations relate generally to systems, methods, and devices for characterizing the performance of an ultrasound imaging device.BACKGROUND

[0002] Ultrasound imaging is an imaging method that uses sound waves to produce images of structures or features within a region probed by the sound waves. In biological or medical applications, ultrasound images can be captured in real-time to show movement of internal organs as well as blood flowing through the blood vessels. The images can provide valuable information for diagnosing and directing treatment for a variety of diseases and conditions.SUMMARY

[0003] Medical ultrasound is an imaging modality that is based on the reflection of propagating sound waves at the interface between different tissues. Advantages of ultrasound imaging with respect to other imaging modalities may include one or more of: (1) its non- invasive and non-ionizing nature, (2) its reduced costs, (3) its portability, and (4) its ability to provide a good temporal resolution, for example on the order of millisecond or better. Point- of-care ultrasound (POCUS) may be used at bedside by healthcare providers as a real-time tool for answering clinical questions (e.g., whether a patient has developmental hip dysplasia). A trained clinician may perform both the task of acquiring and the task of interpreting ultrasound images, without the need for a radiologist to analyze ultrasound images acquired by a highly trained technician. Depending on specifics of the ultrasound examination, there may still be highly specialized training to learn different protocols for acquiring medically relevant images that are high quality images.

[0004] Presently, most ultrasound examinations are done by pressing a portion of an ultrasound imaging device (e.g., an ultrasound probe or scanner) against a surface or inside a cavity of a patient’s body, adjacent to the area being studied. After a patient is positioned in an appropriate way, a clinician moves the ultrasound probe around an area of a patient’s bodyuntil the clinician finds a location and pose of the probe that results in an image of the anatomical structures of interest with sufficiently high quality. After the appropriate location and pose of the probe has been determined, the clinician can proceed to use the probe to acquire and save individual frames (e.g., two-dimensional images) or image stacks of ultrasound image data for analysis, diagnosis, and / or pathology detection.

[0005] International standards and national regulations, such as the International Electrotechnical Commission (EEC) standard 60601, establish requirements for the mechanical, electrical, and thermal safety for ultrasound imaging devices. Manufacturers also specify a device operating temperature (an allowable temperature range of the local ambient environment at which the ultrasound device operates) that is compatible with the device’s application and safe for the operator and patient.

[0006] To ensure that an ultrasound device works as intended, there is a need to test (e.g., characterize) the device at the specified operating temperature. An existing approach for testing an ultrasound device is to place a test phantom (also called an imaging phantom) in a fluid bath and contact the ultrasound device with the test phantom after the test phantom reaches the fluid bath temperature to test the device’s performance characteristics. However, it can take a long time (e.g., 2 hours or more) for the test phantom to reach the fluid bath temperature. Not only that, it is also challenging to maintain the temperature of the test phantom (e.g., at the fluid bath temperature) while testing the ultrasound device due to heat dissipating from the device to the test phantom and / or due to heat loss to the ambient environment. Furthermore, it is also challenging if not impossible to independently control the operating ambient temperature with the current setup, since the fluid bath temperature would change with the ambient condition. Another existing approach for testing an ultrasound device is to image / test the device in ambient air. The drawback of this approach is that it does not accurately represent the actual operating condition of the ultrasound device, under which the device is in direct contact with the skin and / or is placed inside a cavity of a patient’s body, and where the skin and / or the cavity of the patient’s body tend to be of higher temperature than that of ambient air.

[0007] Accordingly, improved methods, devices, and systems that enable ultrasound devices to be tested at their actual operating conditions are desirable.

[0008] Disclosed herein is a phantom (e.g., a test phantom) that can be used to test / characterize the imaging performance and / or thermal characteristics of an ultrasound device at the operating ambient temperature (e.g., 0 to 30 °C, 0 to 35 °C, or 0 to 40 °C) of the device. According to some embodiments disclosed herein, the phantom comprises a tissuemimicking material capable of simulating human skin temperature (e.g., 32°C - 36 °C) and a thermally conductive coil positioned at an interior of the phantom. The temperature of the phantom can be controlled by varying a value of an output parameter (e.g., power, current, number of coils activated, regions of coils activated, fluid flow rate inside the coils, etc.) of the coil. In some embodiments disclosed herein, during ultrasound device testing, the phantom is placed in a test environment whose temperature (e.g., operating ambient temperature or device operating temperature) can be controlled independently of the temperature of the phantom. In some embodiments disclosed herein, during ultrasound device testing, the temperature of the phantom can be controlled so that a contact area between the ultrasound device and the phantom is maintained at skin temperature.

[0009] Accordingly, in some embodiments, the disclosed device, system, and / or method advantageously improve user safety by providing test conditions that are representative of the actual operating conditions of the ultrasound device.

[0010] The systems, methods, and devices of this disclosure have several innovative aspects, the desirable attributes disclosed herein may be derived from one or more of the innovative aspects individually or as a combination, in accordance with some embodiments.

[0011] In accordance with some embodiments, a method of determining performance characteristics of an ultrasound probe via a phantom, the method includes controlling a temperature of an ambient environment of the phantom to a first temperature value. The method includes controlling a temperature of an interface between the phantom and the ultrasound probe to a second temperature value. The method includes, while the temperature of the ambient environment of the phantom is at the first temperature value, acquiring one or more ultrasound images via the ultrasound probe while maintaining the temperature of an interface between the phantom and the ultrasound probe at the second temperature value.

[0012] In some embodiments, the phantom includes a thermally conductive coil positioned at an interior of the phantom.

[0013] In some embodiments, the method includes, while acquiring the one or more ultrasound images, changing a value of an output parameter of the coil so as to maintain the temperature of the interface between the phantom and the ultrasound probe at the second temperature value.

[0014] In some embodiments, the phantom comprises a tissue-mimicking material capable of simulating skin temperature.

[0015] In some embodiments, the tissue-mimicking material comprises agar.

[0016] In some embodiments, the tissue-mimicking material comprises glycerin.

[0017] In some embodiments, the tissue-mimicking material remains in a solid state while (1) the temperature of the ambient environment of the phantom is at the first temperature value and (2) the temperature of the interface between the phantom and the ultrasound probe at the second temperature value.

[0018] In some embodiments, the first temperature value is between 0 and 30 °C inclusive.

[0019] In some embodiments, the second temperature value is between 30 - 35 °C inclusive.

[0020] In some embodiments, a height of the phantom is comparable to a depth of penetration of the ultrasound probe.

[0021] In accordance with some embodiments, a phantom for determining performance characteristics of an ultrasound probe includes a tissue-mimicking material capable of simulating skin temperature; and a thermally conductive coil positioned at an interior of the phantom.

[0022] In some embodiments, the thermally conductive coil is about 1-3 cm from a surface of the phantom.

[0023] In some embodiments, the phantom includes a temperature sensor for measuring a temperature at an interface between the phantom and the ultrasound probe.

[0024] In some embodiments, the tissue-mimicking material comprises agar.

[0025] In some embodiments, the tissue-mimicking material comprises glycerin.

[0026] In some embodiments, a height of the phantom is comparable to a depth of penetration of the ultrasound probe.

[0027] In some embodiments, the height of the phantom does not exceed 15 cm.

[0028] In some embodiments, a diameter of the phantom does not exceed 10 cm.

[0029] In some embodiments, a height of the thermally conductive coil is within 85% of a height of the phantom.

[0030] In accordance with some embodiments, a method of constructing a phantom for determining performance characteristics of an ultrasound probe includes positioning at least a portion of a thermally conductive coil within an interior of a mold; placing a liquid mixture into the mold, the liquid mixture fully covering the at least a portion of thermally conductive coil within the interior of the mold; and curing the liquid mixture component in the mold to form a cured component. The at least a portion of the thermally conductive coil is encapsulated by the cured component. The cured component and the thermally conductive coil form the phantom.

[0031] In some embodiments, the liquid mixture includes a tissue-mimicking material capable of simulating skin temperature.

[0032] In some embodiments, the tissue-mimicking material comprises agar.

[0033] In some embodiments, the liquid mixture includes glycerin, aluminum oxide, and silicon carbide.

[0034] In some embodiments, the method includes, while curing the liquid mixture component in the mold, adding a preservation solution to the liquid mixture.

[0035] In some embodiments, the preservation solution includes benzalkonium chloride and glycerol.

[0036] In some embodiments, the curing time is at least 5 hours.

[0037] In some embodiments, the method includes after the curing, controlling a temperature of an ambient environment of the phantom to a first temperature value; controlling a temperature of an interface between the phantom and the ultrasound probe to a second temperature value; and while the temperature of the ambient environment of the phantom is at the first temperature value, acquiring one or more ultrasound images via the ultrasound probewhile maintaining the temperature of an interface between the phantom and the ultrasound probe at the second temperature value.

[0038] Note that the various embodiments described above can be combined with any other embodiments described herein. The features and advantages described in the specification are not all inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes and may not have been selected to delineate or circumscribe the inventive subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The disclosed aspects will hereinafter be described in conjunction with the appended drawings, provided to illustrate and not to limit the disclosed aspects, wherein like designations denote like elements.

[0040] Figure 1 illustrates an exemplary operating environment, in accordance with some embodiments.

[0041] Figure 2 illustrates a block diagram of an ultrasound device in accordance with some embodiments.

[0042] Figure 3 illustrates a block diagram of a computing device in accordance with some embodiments.

[0043] Figure 4 illustrates an exemplary environment for characterizing the performance of an ultrasound device, in accordance with some embodiments.

[0044] Figures 5 A to 5D illustrate, respectively, a perspective view, a plan view, a side view, and a side interior view of a test phantom, in accordance with some embodiments.

[0045] Figures 6A to 6C are graphs illustrating the acoustic properties of a tissue mimicking material, in accordance with some embodiments.

[0046] Figures 7A and 7B illustrate a flowchart diagram for a method of determining performance characteristics of an ultrasound probe via a phantom, in accordance with some embodiments.

[0047] Figures 8A and 8B illustrate a flowchart diagram for a method of constructing a phantom for determining performance characteristics of an ultrasound probe, in accordance with some embodiments.

[0048] Reference will now be made to implementations, examples of which are illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without requiring some of these specific details.DESCRIPTION OF IMPLEMENTATIONS

[0049] Figure 1 illustrates an exemplary operating environment 100, in accordance with some embodiments.

[0050] In some embodiments, the operating environment 100 includes one or more ultrasound devices (e.g., ultrasound device 200-1 and ultrasound device 200-2). According to some embodiments of the present disclosure, the ultrasound device 200 is also referred to as an ultrasound imaging device or an ultrasound imaging system. In some embodiments, the ultrasound device 200 is a portable handheld device. In some embodiments, the ultrasound device 200 includes a probe portion that includes transducers (e.g., transducers 220, Figure 2). In some embodiments, the transducers are arranged in an array. In some embodiments, the ultrasound device 200 includes an integrated control unit and user interface. In some embodiments, the ultrasound device 200 includes a probe that communicates with a control unit and user interface that is external to the housing of the probe itself. During operation, the ultrasound device 200 (e.g., via the transducers) produces sound waves 120 that are transmitted toward an organ, such as a heart or a lung, of a respective patient 110 (e.g., patient 110-1 or patient 110-2). The internal organ, or other object(s) to be imaged, may reflect a portion of the sound waves toward the probe portion of the ultrasound device 200, which are received by the transducers 220.

[0051] In some embodiments, the ultrasound device 200 uses the received signals to generate an ultrasound image that is displayed on a display (e.g., display 218, Figure 2) of the ultrasound device. In some embodiments, the ultrasound device 200 uses the received signals to generate an ultrasound image that is displayed on a display 162 of an electronic device 160(e.g., a computing device) that is communicatively connected (e.g., wirelessly or via a wired connection, such as cable 158) to the ultrasound device.

[0052] In some embodiments, the ultrasound device 200 is communicatively coupled through communication network(s) 106 to a computer system 130 (e.g., a computer device). For example, the ultrasound device 200 transmits the received signals to computer system 130, which uses the received signals to create an image 150 that is also known as a sonogram. In some embodiments, the computing device 130 includes a display 140 (e.g., a display device) for displaying ultrasound images, and other input and output devices (e.g., keyboard, touch screenjoystick, touchpad, and / or speakers).

[0053] In some embodiments, the computer system 130 and the ultrasound device 200 are co-located at the same location (e.g., in the same room where the ultrasound device 200 is deployed, such as ultrasound device 200-1 and computer system 130-1 in Figure 1). In some embodiments, the ultrasound device 200 and the computer system 130 are located at different locations (e.g., such as computer system 130-2 in Figure 1).

[0054] In some embodiments, the computer system 130 includes a data receiving module 354 that is configured to receive data from one or more ultrasound devices 200, such as ultrasound medical imaging data and / or ultrasound data for user authentication. The computer system 130 includes a data processing module 358 that is configured to process the received data. In some embodiments, the computer system 130 includes a database 380. Further details of the data receiving module 354, data processing module 358, and database 380 are discussed with respect to Figure 3.

[0055] Figure 2 illustrates a block diagram of an exemplary ultrasound device 200 in accordance with some embodiments.

[0056] The ultrasound device 200 may be used to perform different types of imaging. For example, the ultrasound device 200 may be used to perform one-dimensional imaging, also known as A-Scan, two-dimensional imaging, also known as B scan, three-dimensional imaging, also known as C scan, and Doppler imaging. The ultrasound device 200 may be switched to different imaging modes, including without limitation linear mode and sector mode, and electronically configured under program control.

[0057] In some embodiments, the ultrasound device 200 includes one or more processors 202, one or more communication interfaces 204 (e.g., network interface(s)), memory 206, and one or more communication buses 208 for interconnecting these components (sometimes called a chipset).

[0058] In some embodiments, the ultrasound device 200 includes one or more input interfaces 210 that facilitate user input. For example, in some embodiments, the input interfaces 210 include port(s) 212 and button(s) 214. In some embodiments, the port(s) can be used for receiving a cable (e.g., cable 158) for powering or charging the ultrasound device 200, or for facilitating communication between the ultrasound device and other devices (e.g., computing device 130, electronic device 160, display device 140, printing device, and / or other input output devices and accessories).

[0059] In some embodiments, the ultrasound device 200 includes a power supply 216. For example, in some embodiments, the ultrasound device 200 is battery-powered. In some embodiments, the ultrasound device is powered by a continuous AC power supply.

[0060] In some embodiments, the ultrasound device 200 includes a display 218 for displaying ultrasound imaging data and / or other notifications generated by the ultrasound device 200.

[0061] In some embodiments, the ultrasound device 200 includes a probe portion that includes transducers 220, which may also be referred to as transceivers or imagers. Examples of transducers 220 include, without limitation, piezoelectric micromachined ultrasonic transducers (PMUT) and capacitive micromachined ultrasonic transducers (CMUT). In some embodiments, the transducers 220 are based on photo-acoustic or ultrasonic effects. For ultrasound imaging, the transducers 220 generate and transmit ultrasonic waves towards a target (e.g., a target organ, blood vessels, etc.) to be imaged. The transducers 220 receive reflected sound waves (e.g., echoes) that bounce off body tissues. The reflected waves are then converted to electrical signals and / or ultrasound images. In some embodiments, the probe portion of the ultrasound device 200 is separately housed from the computing and control portion of the ultrasound device. In some embodiments, the probe portion of the ultrasound device 200 is integrated in the same housing as the computing and control portion of the ultrasound device 200. In some embodiments, part of the computing and control portion of the ultrasound device is integrated in the same housing as the probe portion, and part of thecomputing and control portion of the ultrasound device is implemented in a separate housing that is coupled communicatively with the part integrated with the probe portion of the ultrasound device. In some embodiments, the probe portion of the ultrasound device has a respective transducer array that is tailored to a respective scanner type (e.g., linear, convex, endocavitary, phased array, transesophageal, 3D, and / or 4D). In the present disclosure, “ultrasound probe” may refer to the probe portion of an ultrasound device, or an ultrasound device that includes a probe portion.

[0062] In some embodiments as used herein, a transducer 220 is also known as a “pixel.” In some embodiments, multiple pixels / transducers (e.g., 4, 8, 16, or 64) are grouped together to form a transducer element 221. For example, in some embodiments, the ultrasound device 200 is configured to control transmit (Tx) firings (the transmissions of ultrasonic waveforms from a transducer pixel or a transducer element) by sequentially activating one transducer 220 at a time. In some embodiments, the ultrasound device 200 is configured to control Tx firings by sequentially activating two or more transducers (e.g., a transducer element 221) at a time.

[0063] In some embodiments, the ultrasound device 200 includes a control circuitry 291 that is configured to control transducers 220 and / or transducer elements 221 to send ultrasound waves toward the target object being imaged while other transducers 220 and / or transducer elements 221, at the same time, receive the ultrasound waves / ultrasonic energy reflected from the target object, and generate electrical charges based on the same in response to the received ultrasound waves / ultrasonic energy. To generate the pressure waves, the ultrasound device 200 may include a number of transmit (Tx) channels 292 and a number of receive (Rx) channels 293. The transmit channels 292 may include a number of components that drive the transducers 220 (e.g., transducer elements 221) with a voltage pulse at a frequency that they are responsive to. This causes an ultrasonic waveform to be emitted from the transducers 220 towards an object to be imaged.

[0064] In some embodiments, the ultrasound device 200 includes radios 230. The radios 230 enable one or more communication networks, and allow the ultrasound device 200 to communicate with other devices, such as the computing device 130 in Figures 1 and 3, the display device 140 in Figure 1, and / or the electronic device 160 in Figure 1. In some implementations, the radios 230 are capable of data communications using any of a variety ofcustom or standard wireless protocols (e.g., IEEE 802.15.4, Wi-Fi, ZigBee, 6L0WPAN, Thread, Z-Wave, Bluetooth Smart, ISA100.5A, WirelessHART, MiWi, Ultrawide Band (UWB), software defined radio (SDR) etc.) custom or standard wired protocols (e.g., Ethernet, HomePlug, etc.), and / or any other suitable communication protocol, including communication protocols not yet developed as of the filing date of this document.

[0065] The memory 206 includes high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices; and, optionally, includes non-volatile memory, such as one or more magnetic disk storage devices, one or more optical disk storage devices, one or more flash memory devices, or one or more other nonvolatile solid state storage devices. The memory 206, optionally, includes one or more storage devices remotely located from one or more processor(s) 202. The memory 206, or alternatively the non-volatile memory within the memory 206, includes a non-transitory computer-readable storage medium. In some implementations, the memory 206, or the non-transitory computer- readable storage medium of the memory 206, stores the following programs, modules, and data structures, or a subset or superset thereof:• operating logic 240 including procedures for handling various basic system services and for performing hardware dependent tasks;• a communication module 242 (e.g., a radio communication module) for connecting to and communicating with other network devices (e.g., a local network, such as a router that provides Internet connectivity, networked storage devices, network routing devices, server systems, computer device 130, electronic device 160, and / or other connected devices etc.) coupled to one or more communication networks via the communication interface(s) 204 (e.g., wired or wireless);• application 250 for acquiring ultrasound data (e.g., imaging data) of a patient, and / or for controlling one or more components of the ultrasound device 200 and / or other connected devices (e.g., in accordance with a determination that the ultrasound data meets, or does not meet, certain conditions). In some embodiments, the application 250 includes: o an acquisition module 252 for acquiring ultrasound data (e.g., via control circuitry 291 and transmit channels 292). In some embodiments, the ultrasound data includes imaging data. In some embodiments, the acquisition module 252activates the transducers 220 (e.g., less than all of the transducers 220, different subset(s) of the transducers 220, all the transducers 220, transducer elements 221, etc.) according to whether the ultrasound data meets one or more conditions associated with one or more quality requirements; o a receiving module 254 for receiving ultrasound data (e.g., via control circuitry 291 and receive channels 293); o a transmitting module 256 for transmitting ultrasound data to other device(s) (e.g., a server system, computer device 130, display device 140, electronic device 160, and / or other connected devices etc.); o a transducer control module 260 for adjusting imaging control parameters (e.g., between an authentication scan and a diagnostic scan, or between diagnostic scans of different anatomies); o an authentication module 262 for authenticating a user of the ultrasound device 200 (e.g., by transmitting the device to a computer system 130 for authentication). In some embodiments, the authentication module 262 is used to provision the ultrasound device 200 (e.g., during initial setup) and / or to associate additional users with the ultrasound device 200. For example, in some embodiments, prior to acquiring ultrasound medical imaging data, the authentication module 292 provisions (e.g., sets up) the ultrasound device 200 to associate the ultrasound device 200 with one or more authorized subjects (e.g., clinicians and / or patients). In some embodiments, during device provisioning, the authentication module 292 acquires biometric data (e.g., fingerprints, thumbprints, handprints, etc.) of the subjects and transmits the information to a computer system (e.g., computer system 130), where the biometric information is added to a database of authorized (e.g., registered) users (e.g., as biometric information 394, Figure 3); device data 280 for the ultrasound device 200, including but not limited to: o device settings 282 for the ultrasound device 200, such as default options and preferred user settings. In some embodiments, the device settings 282 include imaging control parameters. For example, in some embodiments, the imagingcontrol parameters include one or more of: a number of transducers that are activated, a power consumption threshold of the probe, an imaging frame rate, a scan speed, a depth of penetration, and other scan parameters that control the power consumption, heat generation rate, and / or processing load of the probe; o user settings 284, such as a preferred gain, depth, zoom, and / or focus settings. In some embodiments, user settings are loaded automatically (e.g., without user intervention) after the user authenticates using an ultrasound scan as described herein; o ultrasound scan data 286 (e.g., imaging data) that are acquired (e.g., detected, measured) by the ultrasound device 200 (e.g., via transducers 220); o an atlas 290. In some embodiments, the atlas 290 includes anatomical structures of interest. In some embodiments, the atlas 290 includes three-dimensional representations of the anatomical structure of interest (e.g., hip, heart, lung, and / or other anatomical structures);

[0066] Each of the above identified executable modules, applications, or sets of procedures may be stored in one or more of the previously mentioned memory devices, and corresponds to a set of instructions for performing a function described above. The above identified modules or programs (i.e., sets of instructions) need not be implemented as separate software programs, procedures, or modules, and thus various subsets of these modules may be combined or otherwise re-arranged in various implementations. In some implementations, the memory 206 stores a subset of the modules and data structures identified above. Furthermore, the memory 206 may store additional modules or data structures not described above. In some embodiments, a subset of the programs, modules, and / or data stored in the memory 206 are stored on and / or executed by a server system, and / or by an external device (e.g., computing device 130, display device 140, or electronic device 160).

[0067] Figure 3 illustrates a block diagram of a computer system 130 in accordance with some embodiments.

[0068] In some embodiments, the computer system 300 is a server or control console that is in communication with the ultrasound device 200 (e.g., ultrasound probe). In some embodiments, the computer system 300 is integrated into the same housing as the ultrasounddevice 200. In some embodiments, the computer system 300 is a smartphone, tablet device, or other portable computing devices. In some embodiments, the computer system 300 may be provided by a combination of components integrated into the same housing as the ultrasound device 200, and a smartphone, tablet device, or other portable computing devices.

[0069] The computer system 300 includes one or more processors 302 (e.g., processing units of CPU(s)), one or more network interfaces 304, memory 306, and one or more communication buses 308 for interconnecting these components (sometimes called a chipset), in accordance with some implementations.

[0070] In some embodiments, the computer system 300 includes one or more input devices 310 that facilitate user input, such as a keyboard, a mouse, a voice-command input unit or microphone, a touch screen display, a touch-sensitive input pad, a gesture capturing camera, or other input buttons or controls. In some embodiments, the computer system 300 uses a microphone and voice recognition or a camera and gesture recognition to supplement or replace the keyboard. In some embodiments, the computer system 300 includes one or more output devices 312 that enable presentation of user interfaces and display content, such as one or more speakers and / or one or more visual displays (e.g., display device 140).

[0071] The memory 306 includes high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices; and, optionally, includes non-volatile memory, such as one or more magnetic disk storage devices, one or more optical disk storage devices, one or more flash memory devices, or one or more other nonvolatile solid state storage devices. The memory 306, optionally, includes one or more storage devices remotely located from the one or more processors 302. The memory 306, or alternatively the non-volatile memory within the memory 306, includes a non-transitory computer-readable storage medium. In some implementations, the memory 306, or the non- transitory computer-readable storage medium of the memory 306, stores the following programs, modules, and data structures, or a subset or superset thereof:• an operating system 322 including procedures for handling various basic system services and for performing hardware dependent tasks;• a communication module 323 (e.g., a radio communication module) for connecting to and communicating with other network devices (e.g., a local network, such as a router that provides Internet connectivity, networked storage devices, network routingdevices, server systems, computer device 130, ultrasound device 200, and / or other connected devices etc.) coupled to one or more communication networks via the network interface 304 (e.g., wired or wireless); a user interface module 324 for enabling presentation of information (e.g., a graphical user interface for presenting application(s), widgets, websites and web pages thereof, games, audio and / or video content, text, etc.) either at the computer system 300 or another device; application 350 for acquiring ultrasound data (e.g., imaging data) from a patient. In some embodiments, the application 350 is used for receiving data (e.g., ultrasound data, imaging data, etc.) acquired via an ultrasound device 200. In some embodiments, the application 350 is used for controlling one or more components of an ultrasound device 200 (e.g., the probe portion, and / or the transducers) and / or other connected devices (e.g., in accordance with a determination that the data meets, or does not meet, certain conditions). In some embodiments, the application 350 includes: o an acquisition module 352 for acquiring ultrasound data. In some embodiments, the ultrasound data includes imaging data acquired by an ultrasound probe.; o a receiving module 354 for receiving ultrasound scan data. In some embodiments, the ultrasound scan data includes imaging data acquired by an ultrasound probe; o a transmitting module 356 for transmitting ultrasound data (e.g., imaging data) to other device(s) (e.g., a server system, computer device 130, display device 140, ultrasound device 200, and / or other connected devices etc.); o a processing module 358 for processing ultrasound data and / or other data; and o a transducer control module 360 for adjusting imaging control parameters (e.g., between an authentication scan and a diagnostic scan, or between diagnostic scans of different anatomies); and a database 380, including: o ultrasound scan data 382 (e.g., imaging data) that are acquired (e.g., detected, measured) by one or more ultrasound devices 200;user settings 284, such as a preferred gain, depth, zoom, and / or focus settings. In some embodiments, user settings are loaded automatically (e.g., without user intervention) after the user authenticates or logs onto a computing device that is communicatively connected with the ultrasound device 200; image quality requirements data 384. In some embodiments, the image quality requirements data 384 include clinical requirements for determining the quality of an ultrasound image; an atlas 386. In some embodiments, the atlas 386 includes anatomical structures of interest. In some embodiments, the atlas 386 includes three-dimensional representations of the anatomical structure of interest (e.g., hip, heart, or lung); imaging control parameters 388. For example, in some embodiments, the imaging control parameters include one or more of: a number of transducers that are activated, a power consumption threshold of the probe, an imaging frame rate, a scan speed, a depth of penetration, and other scan parameters that control the power consumption, heat generation rate, and / or processing load of the probe; ultrasound scan data processing models 390 for processing ultrasound data. For example, in some embodiments, the ultrasound scan data processing models 390 are trained neural network models that are trained to determine whether an ultrasound image meets quality requirements corresponding to a scan type, or trained to output an anatomic plane corresponding to an anatomical structure of an ultrasound image, or trained to predict, based on a sequence of ultrasound images and their quality scores, whether a subsequent frame to be acquired by an ultrasound probe will contain certain anatomical structures and / or landmarks of interest; labeled images 392 (e.g., a databank of images), including images for training the models that are used for processing new ultrasound data, and / or new images that have been or need to be processed. In some embodiments, the labeled images 392 are images of anatomical structures that have been labeled with their respective identifiers and relative positions; ando authorized users data 394, including data of users that are authorized to use a respective ultrasound device. For example, in some embodiments, the authorized users data 394 are categorized according to respective identifiers corresponding to respective ultrasound devices. A respective identifier can be associated with one or more authorized subjects;

[0072] Each of the above identified elements may be stored in one or more of the memory devices described herein, and corresponds to a set of instructions for performing the functions described above. The above identified modules or programs need not be implemented as separate software programs, procedures, modules or data structures, and thus various subsets of these modules may be combined or otherwise re-arranged in various embodiments. In some embodiments, the memory 306, optionally, stores a subset of the modules and data structures identified above. Furthermore, the memory 306 optionally stores additional modules and data structures not described above. In some embodiments, a subset of the programs, modules, and / or data stored in the memory 306 are stored on and / or executed by the ultrasound device 200. In some embodiments, a subset of the programs, modules, and / or data stored in the memory 306 are stored on and / or executed by the electronic device 160.

[0073] Some embodiments of the present disclosure are directed to methods and devices for characterizing the performance characteristics of an ultrasound device. According to some embodiments of the present disclosure, a temperature-controlled test phantom that can simulate human skin temperature can be used to test the imaging and thermal performance of an ultrasound device. During device testing, the phantom can be operated in a test chamber. The temperature of the test chamber can be adjusted to different ambient temperatures while the temperature of the phantom can be maintained at or near human skin temperature (e.g., 32°C - 36°C) at an interface between the phantom and the ultrasound probe.

[0074] Figure 4 illustrates an exemplary environment 400 for characterizing the performance of an ultrasound device 200, in accordance with some embodiments. In the environment 400, the ultrasound device 200 and a temperature-controlled test phantom 404 are placed in an ambient environment 402 (e.g., a test chamber, a room, or an enclosed space).

[0075] The phantom 404 comprises a tissue-mimicking material 406 that can simulate skin temperature. In some embodiments, the phantom 404 includes a coil 408 that is positioned at the interior of the phantom 404. The coil 408 can be a thermally conductive coil that conductsheat from the coil to the tissue-mimicking material 406. In some embodiments, the coil 408 comprises one or more tubes (e.g., tubing) through which a fluid (e.g., water, thermally conductive fluid etc.) can flow. The tubes can be made of metal (e.g., copper, carbon steel, or stainless steel).

[0076] In some embodiments, the phantom 404 is coupled to a chiller / heater system 410 (e.g., that is placed outside the ambient environment 402), by connecting the ends of the coil 408 to insulated chiller lines 412. The chiller / heater system 410 controls the temperature of the fluid flowing through the coil 408. A thermocouple 414 can be used to detect the temperature at an interface 416 between the phantom 404 and the ultrasound device 200.

[0077] As disclosed herein, the temperature of the ambient environment 402 and the temperature of the phantom 404 are independently controllable. For example, an operator can control the temperature of the ambient environment 402 to correspond to an operating temperature of the ultrasound device 200, and control the temperature of the phantom (e.g., by adjusting as a heating time, power to the coil, current flowing through the coil, number of coils activated, region(s) of coil that are activated, or fluid flow rate in the interior of the coil, etc.) to correspond to human skin temperature. During device testing, heat generated from the ultrasound probe head can cause the temperature at the interface 416 to increase. An operator or an automated feedback system can adjust a value of an output parameter of the coil 408 (e.g., such as a heating time, power to the coil, current flowing through the coil, number of coils activated, region(s) of coil that are activated, or fluid flow rate in the interior of the coil, etc.) to maintain the temperature of an interface 416 between the phantom and the ultrasound probe to be similar to that of human skin temperature.

[0078] Thus, the test phantom 404 disclosed herein improves existing approaches of ultrasound device testing by enabling the operating ambient temperature and the phantom temperature to be independently controllable. The disclosed test phantom 404 can more consistently maintain a uniform temperature distribution in the phantom body (e.g., via the combination of the tissue-mimicking material 406 and the coil 408) compared to currently available setups. In some embodiments, compared to the fluid bath approach, the disclosed setup takes less time (e.g., 30 minutes or less) to reach equilibrium temperature.

[0079] In some embodiments, the tissue-mimicking material 406 comprises agar. Agar is a tissue mimicking material that is utilized in medical imaging. For example, in the articletitled “Acoustic and thermal characterization of agar based phantoms used for evaluating focused ultrasound exposures,” Journal of Therapeutic Ultrasound (2017) 5: 14, the authors conducted experiments to characterize acoustic and thermal properties of agar materials for fabricating brain and muscle tissue mimicking phantoms. In another article titled “Agar ultrasound phantoms for low-cost training without refrigeration,” African Journal of Emergency Medicine (2016) 6, 18-23, the authors evaluated whether agar models would produce ultrasound images adequate for training healthcare professionals. These two articles are incorporated by reference herein in their entireties.

[0080] In the present disclosure, agar is found to be a suitable candidate for the test phantom 404 because it solidifies (e.g., cures, sets, transforms from a liquid state to a solid state) at around 40°C, which is typically higher than the range of operating temperatures of the ultrasound device 200. Thus, using agar as the tissue-mimicking material 406 ensures that the test phantom 404 will remain solid for the temperatures at which the ultrasound device will be tested.

[0081] In some embodiments, a procedure for making a tissue-mimicking material 406 is modified from Souza et al, “Standard operating procedure to prepare agar phantoms,” 2016 J. Phys.: Conf. Ser. 733 012044, which is incorporated by reference herein in its entirety. In some embodiments, the procedure includes the following steps:1) Set the hot plate to approximately 90 - 100 °C.2) Measure out the desired amount of deionized (DI) water in a beaker. Place the water on the hot plate and allow it to heat up to 90 - 100 °C.3) Weigh out the glycerin, aluminum oxide, silicon carbide and benzalkonium chloride and add them all to a reaction beaker in that order.4) Stir the mix in the reaction beaker with a magnetic stir bar at around 300-500 rpm. Stir for 5 minutes or so until the mixture is uniform. It should look like a dark gray paste.5) Stir for 2 minutes with a glass stirring rod until it looks homogenous.6) Carefully remove the water beaker from the hot plate and pour the heated water into the reaction beaker. Place the reaction beaker on the hot plate at around 90 °C.7) Add the agar to the reaction mix.8) Immediately start the mechanical stirring and set the stir speed to approximately 500 rpm.9) Let the reaction sit for 60 minutes or longer until it thickens and becomes highly viscous. Maintain reaction temperature between 80-90 °C. Increase the stir speed gradually to approximately 1000 rpm.10) Continuously stir while decreasing the temperature to between 40 - 50 °C. When the temperature is in that range, stir for an additional 10 minutes.11) Remove from heat and stir for 5 minutes with a glass stirring rod.12) Transfer the reaction solution to the phantom mold. Leave it out to set for around 5 hours or longer.13) While the phantom is setting, create the preservation solution by mixing together DI water, benzalkonium chloride and glycerol. The amount of preservation solution should be around 2% the weight of the phantom. For example, for a 750g phantom, make about 15g of preservation solution.

[0082] Table 1 illustrates a list of materials for making the tissue-mimicking material 406 and their relative weight percentages (in solution), in accordance with some embodiments.Table 1

[0083] Table 2 illustrates a list of materials for a preservation solution and their relative weight percentages (in solution), in accordance with some embodiments.Table 2

[0084] In some embodiments, the mass of the tissue-mimicking material 406, when solidified, is about 700 - 800 g within a predefined margin (e.g., ± 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%).

[0085] Figures 5 A to 5D illustrate, respectively, a perspective view, a plan view, a side view, and a side interior view of a test phantom 404, in accordance with some embodiments. In some embodiments, the test phantom 404 has a cylindrical shape that includes a diameter 502 and a height 504. In some embodiments, the diameter 502 of the test phantom 404 is approximately 9 - 14 cm within a first predefined margin (e.g., within ± 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%). In some embodiments, the height of the phantom is approximately 11 - 15 cm within a second predefined margin (e.g., within ± 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%). In some embodiments, the height 504 of the test phantom 404 is comparable to a depth of penetration of the ultrasound device 200.

[0086] In some embodiments, at least a portion of the coil 408 is positioned in the interior of the phantom 404 (e.g., embedded in the tissue mimicking material 406). For example, Figure 5D illustrates that the coil 408 has a height 506 that is less than the height 504 of the phantom. In some embodiments, the height 506 of the coil 408 does not exceed 85% of the height 504 of the phantom 404 (e.g., within a predefined margin, such as ± 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%). As an example, when the height of the phantom 404 is 15 cm, the height of the coil 408 does not exceed 12.8 cm ± 1.3 cm. As another example, when the height of the phantom 404 is about 12 cm, the height of the coil 408 does not exceed 10.2 ± 1.02 cm.

[0087] Figure 5D also illustrates that the coil has a diameter 503 that is less than the diameter 502 of the phantom. In some embodiments, diameter 503 of the coil 408 does not exceed 85% of the diameter 502 of the phantom 404 (e.g., within a predefined margin, such as ± 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%). For example, when the diameter of the phantom is 10 cm, the diameter of the coil can be about 8.5 ± 0.85 cm.

[0088] In Figure 5D, the distance 508 represents a separation between one end 520 of the coil 408 and a surface 516 of the phantom 404 that is in contact with the ultrasound device 200 during device testing. The distance 510 represents a separation between the other end 522 of the coil 408 and the surface 518 of the phantom 404 that is not in contact with the ultrasounddevice 200 during device testing. In some embodiments, the coil 408 is symmetrically positioned within the phantom 404, meaning that the distance 508 is equal to the distance 510 and the distance 512 is equal to the distance 514. In some embodiments, the coil is offset in the vertical direction (e.g., z-direction) such that the distance 508 is greater than the distance 510, so that the region of the tissue-mimicking material 406 that is contacted by the ultrasound device 200 has a temperature that is representative of skin temperature. For example, in some embodiments, the distance 508 is approximately 1 - 3 cm whereas the distance 510 is approximately 0.5 - 1 cm.

[0089] Figures 6A to 6C are graphs illustrating the acoustic properties of a tissue mimicking material 406 that is made using the procedure described above, in accordance with some embodiments. The acoustic properties are measured by positioning a block (e.g., about 1 cm thick) of the tissue mimicking material 406 between a transducer (also referred to as “piston” in the graphs) and a container of water with a submerged hydrophone. The transducer sends a 5 MHz pulse signal, which is transmitted through the tissue mimicking material 406 and the water, and measured by the hydrophone. Control measurements are performed using the same setup without tissue mimicking material.

[0090] Figure 6A shows a graph 602 of the amplitude (in millivolts) versus time for the tissue mimicking material and the control. From the graph 602, the velocity of sound the acoustic impedance can be derived. Figure 6A shows that the velocity of sound through the tissue mimicking material is 1566 m / s, which is similar to that of water (1500 m / s). Figure 6A also shows that the acoustic impedance of the tissue mimicking material is 1.67 MRayl, which is similar to that of water (1.4 MRayl).

[0091] Figure 6B shows a graph 604 of the amplitude (in decibels) versus frequency (in MHz) for the tissue mimicking material (sample) and the control. For both the sample and the control, there is a peak at around 5 MHz, which corresponds to the signal frequency from the transducer.

[0092] Figure 6C shows a graph 606 of the attenuation (in decibels per mm) versus frequency (in MHz), the graph 606 depicts the amount of loss in amplitude per millimeter of thickness of the tissue mimicking material. The test results in Figures 6A to 6C indicate that the tissue mimicking material that is made using the procedure described above has acoustic properties similar to that of water, which is what the human body is mostly composed of.

[0093] Figures 7A and 7B illustrate a flowchart diagram for a method 700 of determining (e.g., characterizing, testing) performance characteristics (e.g., imaging performance characteristics and / or thermal characteristics) of an ultrasound probe (e.g., ultrasound device 200) via a phantom (e.g., a test phantom, such as phantom 404), in accordance with some embodiments. In some embodiments, the method 700 is also applicable to any device that needs to be tested with a phantom that simulates skin temperature. Some operations in the method 700 may be combined and / or the order of some operations may be changed.

[0094] The method includes controlling (702) a temperature of an ambient environment (e.g., air) of the phantom (e.g., in which the phantom is placed) (e.g., ambient environment 402) to a first temperature value within a first predefined margin (e.g., ± 0.5 °C or ± 1.0 °C, or ± 1%, 2%, 3% or 5%). For example, the first temperature value corresponds to an operating temperature of the ultrasound probe (e.g., prior to use). In some embodiments, the phantom is not placed in a liquid bath.

[0095] In some embodiments, the phantom includes (704) a thermally conductive coil (e.g., coil 408) positioned at an interior of the phantom (see, e.g., Figure 5D). In some embodiments, the thermally conductive coil comprises one or more tubes through which a fluid can flow. The coil is coupled to a chiller / heater system that controls the temperature of the fluid flowing through the coil.

[0096] In some embodiments, the phantom comprises a tissue-mimicking material (e.g., tissue-mimicking material 406) that is capable of simulating skin temperature (e.g., of a human subject).

[0097] In some embodiments, the tissue-mimicking material comprises (708) agar. Agar is a suitable candidate for the particular application of characterizing the performance characteristics of an ultrasound probe not only because is agar an acceptable material / standard that is used in medical imaging, but also because it can also simulate thermal and acoustic properties of human tissue (e.g., human skin). Furthermore, agar sets (e.g., solidifies) at around 40°C, which is higher than the typical operating range of an ultrasound probe (e.g., around 0 to 30 °C). Thus, the use of agar as the tissue-mimicking material ensures that the test phantom always remains solid for the temperatures at which the ultrasound probe will be tested.

[0098] In some embodiments, the tissue-mimicking material comprises (710) glycerin (e.g., the agar is stabilized with glycerin).

[0099] In some embodiments, the first temperature is (712) between 0°C and 30°C inclusive, within a threshold value (e.g., within ± 0.5 °C or ± 1.0 °C, or within ± 1%, 2%, 3% or 5%). In some embodiments, the first temperature is between 0°C and 35°C inclusive, within a threshold value (e.g., within ± 0.5 °C or ± 1.0 °C, or within ± 1%, 2%, 3% or 5%). In some embodiments, the first temperature is between 0°C and 40°C inclusive, within a threshold value (e.g., within ± 0.5 °C or ± 1.0 °C, or within ± 1%, 2%, 3% or 5%).

[0100] In some embodiments, a height of the phantom is (714) comparable to the depth of penetration of the ultrasound probe.

[0101] The method includes controlling (716) a temperature of (e.g., at) an interface between the phantom and the ultrasound probe to a second temperature value within a second predefined margin (e.g., ± 0.5 °C or ± 1.0 °C, or ± 1%, 2%, 3% or 5%). The controlling the temperature of the interface between the phantom and the ultrasound probe is performed independently of the controlling the temperature of the ambient environment. In some embodiments, the second temperature value corresponds to skin temperature of a human subject.

[0102] In some embodiments, the second temperature is (718) between 30°C and 35°C inclusive, within a threshold value (e.g., within ± 0.5 °C or ± 1.0 °C, or within ± 1%, 2%, 3% or 5%). In some embodiments, the second temperature is between 32°C and 37°C inclusive, within a threshold value (e.g., within ± 0.5 °C or ± 1.0 °C, or within ± 1%, 2%, 3% or 5%). In some embodiments, the second temperature is between 33°C and 37°C inclusive, within a threshold value (e.g., within ± 0.5 °C or ± 1.0 °C, or within ± 1%, 2%, 3% or 5%).

[0103] In some embodiments, the tissue-mimicking material remains (720) in a solid state while (1) the temperature of the ambient environment of the phantom is at the first temperature value and (2) the temperature of the interface between the phantom and the ultrasound probe at the second temperature value.

[0104] Referring to Figure 7B, the method includes, while the temperature of the ambient environment of the phantom is at the first temperature value, acquiring (722) one or more ultrasound images via the ultrasound probe while maintaining the temperature of aninterface between the phantom and the ultrasound probe at the second temperature value within a predefined margin, such as within ± 0.5 °C or ± 1.0 °C of the second temperature value, or within ± 1%, 2%, 3% or 5% pf the second temperature value.

[0105] In some embodiments, the method includes, while acquiring the one or more ultrasound images, changing (724) a value of an output parameter (e.g., time, power, current, number of coils activated, region(s) of coil that are activated, fluid flow rate in the interior of the coil) of the coil so as to maintain the temperature of the interface between the phantom and the ultrasound probe at the second temperature value (e.g., within a second predefined margin).

[0106] Figures 8A and 8B illustrate a flowchart diagram for a method 800 of constructing a phantom (e.g., test phantom 404) for determining performance characteristics of an ultrasound probe, in accordance with some embodiments. Additional details of the method 800 can be found in Figures 1 to 7B and the accompanying descriptions, and are not repeated for the sake of brevity.

[0107] The method includes positioning (802) at least a portion of a thermally conductive coil within an interior of a mold.

[0108] The method includes placing (804) (e.g., pouring) a liquid mixture into the mold (e.g., a container). The liquid mixture fully (e.g., completely) covers the at least a portion of thermally conductive coil within the interior of the mold.

[0109] In some embodiments, the liquid mixture includes (806) a tissue-mimicking material capable of simulating skin temperature (e.g., of a human subject).

[0110] In some embodiments, the tissue-mimicking material comprises (808) agar.

[0111] In some embodiments, the liquid mixture includes (810) glycerin (glycerol), aluminum oxide, and silicon carbide.

[0112] The method includes curing (812) (e.g., setting, solidifying) the liquid mixture component in the mold to form a cured component The at least a portion of the thermally conductive coil is encapsulated (e.g., fully encapsulated) by the cured component and the cured component and the thermally conductive coil form the phantom.

[0113] In some embodiments, the method 800 includes, while curing the liquid mixture component in the mold, adding (814) a preservation solution to the liquid mixture.

[0114] In some embodiments, the preservation solution includes (816) benzalkonium chloride and glycerol (e.g., glycerin).

[0115] In some embodiments, the curing time is (818) at least 5 hours.

[0116] Referring to Figure 8B, in some embodiments, the method includes after the curing, controlling (820) a temperature of an ambient environment of the phantom to a first temperature value and controlling (822) a temperature of an interface between the phantom and the ultrasound probe to a second temperature value (e.g., independently of controlling the temperature of the ambient environment of the phantom). The method includes, while the temperature of the ambient environment of the phantom is at the first temperature value, acquiring (824) one or more ultrasound images via the ultrasound probe while maintaining the temperature of an interface between the phantom and the ultrasound probe at the second temperature value.

[0117] Although some of various drawings illustrate a number of logical stages in a particular order, stages that are not order dependent may be reordered and other stages may be combined or broken out. While some reordering or other groupings are specifically mentioned, others will be obvious to those of ordinary skill in the art, so the ordering and groupings presented herein are not an exhaustive list of alternatives. Moreover, it should be recognized that the stages could be implemented in hardware, firmware, software or any combination thereof.

[0118] It will also be understood that, although the terms first, second, etc. are, in some instances, used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first segmentation value could be termed a second segmentation value, and, similarly, a second segmentation value could be termed a first segmentation value, without departing from the scope of the various described implementations. The first segmentation value and the second segmentation value are both segmentation values, but they are not the same type of segmentation value.

[0119] The terminology used in the description of the various described implementations herein is for the purpose of describing particular implementations only and is not intended to be limiting. As used in the description of the various described implementations and the appended claims, the singular forms “a”, “an” and “the” are intended to include theplural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “includes,” “including,” “comprises,” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0120] As used herein, the term “if’ is, optionally, construed to mean “when” or “upon” or “in response to determining” or “in response to detecting” or “in accordance with a determination that,” depending on the context. Similarly, the phrase “if it is determined” or “if [a stated condition or event] is detected” is, optionally, construed to mean “upon determining” or “in response to determining” or “upon detecting [the stated condition or event]” or “in response to detecting [the stated condition or event]” or “in accordance with a determination that [a stated condition or event] is detected,” depending on the context.

[0121] The foregoing description, for purpose of explanation, has been described with reference to specific implementations. However, the illustrative discussions above are not intended to be exhaustive or to limit the scope of the claims to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The implementations were chosen in order to best explain the principles underlying the claims and their practical applications, to thereby enable others skilled in the art to best use the implementations with various modifications as are suited to the particular uses contemplated.

Claims

What is claimed is:

1. A method of determining performance characteristics of an ultrasound probe via a phantom, the method comprising: controlling a temperature of an ambient environment of the phantom to a first temperature value; controlling a temperature of an interface between the phantom and the ultrasound probe to a second temperature value; and while the temperature of the ambient environment of the phantom is at the first temperature value, acquiring one or more ultrasound images via the ultrasound probe while maintaining the temperature of an interface between the phantom and the ultrasound probe at the second temperature value.

2. The method of claim 1, wherein the phantom includes a thermally conductive coil positioned at an interior of the phantom.

3. The method of claim 2, further comprising: while acquiring the one or more ultrasound images, changing a value of an output parameter of the coil so as to maintain the temperature of the interface between the phantom and the ultrasound probe at the second temperature value.

4. The method of claim 1, wherein the phantom comprises a tissue-mimicking material capable of simulating skin temperature.

5. The method of claim 4, wherein the tissue-mimicking material comprises agar.

6. The method of claim 4, wherein the tissue-mimicking material comprises glycerin.

7. The method of claim 4, wherein the tissue-mimicking material remains in a solid state while (1) the temperature of the ambient environment of the phantom is at the first temperature value and (2) the temperature of the interface between the phantom and the ultrasound probe at the second temperature value.

8. The method of claim 1, wherein the first temperature value is between 0 and 30 °C inclusive.

9. The method of claim 1, wherein the second temperature value is between 30 - 35 °C inclusive.

10. The method of claim 1, wherein a height of the phantom is comparable to a depth of penetration of the ultrasound probe.

11. A phantom for determining performance characteristics of an ultrasound probe, comprising: a tissue-mimicking material capable of simulating skin temperature; and a thermally conductive coil positioned at an interior of the phantom.

12. The phantom of claim 11, wherein the thermally conductive coil is about 1-3 cm from a surface of the phantom.

13. The phantom of claim 11, further comprising a temperature sensor for measuring a temperature at an interface between the phantom and the ultrasound probe.

14. The phantom of claim 11, wherein the tissue-mimicking material comprises agar.

15. The phantom of claim 11, wherein the tissue-mimicking material comprises glycerin.

16. The phantom of claim 11, wherein a height of the phantom is comparable to a depth of penetration of the ultrasound probe.

17. The phantom of claim 16, wherein the height of the phantom does not exceed 15 cm.

18. The phantom of claim 11, wherein a diameter of the phantom does not exceed 10 cm.

19. The phantom of claim 11, wherein a height of the thermally conductive coil is within85% of a height of the phantom.

20. A method of constructing a phantom for determining performance characteristics of an ultrasound probe, the method comprising: positioning at least a portion of a thermally conductive coil within an interior of a mold; placing a liquid mixture into the mold, the liquid mixture fully covering the at least a portion of thermally conductive coil within the interior of the mold; andcuring the liquid mixture component in the mold to form a cured component, wherein (i) the at least a portion of the thermally conductive coil is encapsulated by the cured component and (ii) the cured component and the thermally conductive coil form the phantom.

21. The method of claim 20, wherein the liquid mixture includes a tissue-mimicking material capable of simulating skin temperature.

22. The method of claim 21, wherein the tissue-mimicking material comprises agar.

23. The method of claim 20, wherein the liquid mixture includes glycerin, aluminum oxide, and silicon carbide.

24. The method of claim 20, further comprising: while curing the liquid mixture component in the mold, adding a preservation solution to the liquid mixture.

25. The method of claim 24, wherein the preservation solution includes benzalkonium chloride and glycerol.

26. The method of claim 20, wherein the curing time is at least 5 hours.

27. The method of claim 20, further comprising: after the curing, controlling a temperature of an ambient environment of the phantom to a first temperature value; controlling a temperature of an interface between the phantom and the ultrasound probe to a second temperature value; and while the temperature of the ambient environment of the phantom is at the first temperature value, acquiring one or more ultrasound images via the ultrasound probe while maintaining the temperature of an interface between the phantom and the ultrasound probe at the second temperature value.

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