WO2010020939A2

WO2010020939A2 - Wireless ultrasound monitoring device

Info

Publication number: WO2010020939A2
Application number: PCT/IB2009/053627
Authority: WO
Inventors: Michael Peszynski; Heather Knowles; Martha Gail Grewe Wilson; Ivan Salgo
Original assignee: Koninklijke Philips Electronics, N.V.
Priority date: 2008-08-21
Filing date: 2009-08-17
Publication date: 2010-02-25
Also published as: WO2010020939A3

Abstract

A monitoring system includes a transducer and a wireless interface. The transducer receives ultrasonic imaging signals reflected from a target object and provides imaging data based on the received imaging signals. The wireless interface communicates the imaging data over a wireless communications network to a host device. The transducer may include a transesophageal echocardiogram (TEE) ultrasound transducer probe, a transnasal TEE (TNE) ultrasound transducer probe, or a transthoracic transducer.

Description

WIRELESS ULTRASOUND MONITORING DEVICE

This invention pertains to the field of ultrasound devices and wireless communications, and more particularly to an ultrasound transducer communicating over a wireless network with an imaging and/or display system for monitoring.

Ultrasound transducers are used extensively to provide imaging, particularly in medical applications. Typically, a transducer is held against a patient's body and emits sound waves or ultrasound transmit beams, which are reflected back to the transducer from an object of interest to generate images. Such ultrasound imaging may be used to observe tissue structures within a human body, such as the heart and vascular system, abdominal organs, a fetus, and the like.

For example, an ultrasound transducer may be attached to the outside of a patient's body in order to provide continuous imaging for monitoring and/or diagnosis. The transducer may include a low profile large aperture matrix on a pad which is attachable to the body using adhesive, as described, for example, in U.S. Patent No. 5,598,845 to CHANDRARATNA et al, issued February 4, 1997, and U.S. Patent Application No. 11/912,588 to PESZYNSKI, filed October 25, 2007, the contents of which are incorporated by reference herein in their entireties. Initially, the transducer pads required mechanical movement to keep the desired anatomy or object of interest in the field of view (FOV). With the advent of three-dimensional (3D) technology, PESZYNSKI, in particular, disclosed a continuous monitoring system that did not require mechanical adjustment, instead relying on electronic steering. However, the transducer pads are required to be cabled to an ultrasound imaging device, which must be positioned, for example, near the patient's bedside.

Other types of ultrasound transducers are designed to be inserted in the human body. For, example, a transesophageal echocardiogram (TEE) provides for insertion of a transducer probe into the patient's esophagus, enabling unobstructed ultrasound imaging of the heart and other internal organs within the chest cavity. Inserting the transducer probe into the esophagus through the nose is referred to as transnasal TEE (TNE), as described, for example, in U.S. Patent No. 6,572,547 to MILLER et al., issued June 3, 2003, and "Transnasal Transesophageal Echocardiography," JOURNAL OF THE AMERICAN SOCIETY OF ECHOCARDIOGRAPHY, Vol. 10 , Issue 7 , pp. 728 - 737, by LANG et al. for cardiac

PCIP.641 monitoring applications, the contents of which are incorporated by reference herein in their entireties. The insertable TNE transducer is cabled directly to an ultrasound imaging device, which may be positioned near the patient bedside, for example, in an operating room environment or in an intensive care unit (ICU) following surgery. The cabling connected to the ultrasonic transducers has a number of drawbacks.

For example, with respect to the adhesive transducer pads, the weight of the cables may affect the physical positioning and direction of the transducers, e.g., when the patient moves, and also the cables themselves may physically interfere with patient accessibility. Also, the cabling limits the location of the monitoring equipment, which must be physically attached to the transducer and thus typically at the patient's bedside. This requires the medical staff to be present in the room with the patient to read the display.

Accordingly, it would be desirable to provide transducers capable of communicating with imaging and/or display devices over a wireless network. Wireless communications eliminate cabling, and provide the ability to display ultrasound images at a centralized location and/or on a device not necessarily located at the patient's bedside, enhancing monitoring capabilities, for example.

In one aspect of the invention, a monitoring system is provided, including a transducer and a wireless interface. The transducer receives ultrasonic imaging signals reflected from a target object and provides imaging data based on the received imagining signals. The wireless interface communicates the imaging data over a wireless communications network to a host device. The wireless communications network may be an Ultra- Wideband (UWB) standard network, for example.

The transceiver may continuously send the imaging data over the wireless communications network to the host device for continuous monitoring of the target object. The host device may include an image generator, which generates at least one image to be displayed on an image display based on the imaging data. The host device may be dedicated to the transducer and located in proximity to a patient being monitored by the transducer. Alternatively, the host device may be located in a centralized monitoring station remote from a patient being monitored by the transducer, and configured to receive additional imaging data from at least one other transducer.

The transducer may include a one-dimensional array for creating a two-dimensional image based on the imaging data, or a two-dimensional array for creating a three- dimensional image based on the imaging data. The host device may include a

PCIP.641 laptop computer.

The transducer may be a transesophageal echocardiogram (TEE) ultrasound transducer probe or a transnasal TEE (TNE) ultrasound transducer probe. The transducer may be locked into position in one of an esophagus or a stomach fundus of a patient being monitored by the transducer for cardiac imaging of the patient. The transducer may include a distal tip, which automatically periodically articulates away from the esophagus or the stomach fundus to prevent tissue necrosis.

In another aspect of the invention, an imaging system for monitoring a patient is provided. The imaging system includes a transesophageal echocardiogram (TEE) ultrasound transducer probe, insertable in the patient being monitored and contacting tissue within the patient, for sending ultrasonic imaging signals into the patient, receiving reflected imaging signals and providing imaging data based on the received imaging signals. The TEE ultrasound transducer probe includes a distal tip configured to periodically articulate away from the tissue to prevent tissue necrosis. The imaging system also includes a transceiver for sending the imaging data over a wireless communications network to a host device, enabling substantially continuous monitoring of the patient at the host device.

The transceiver may receive the ultrasound imaging signals and control signals from the host device over the wireless communications network. Also, the transducer probe may generate the ultrasound imaging signals, and send imaging data based on the ultrasound imaging signals to the host device over the wireless communications network. The transducer probe may generate the ultrasound imaging signals, perform quantification of at least one physiologic parameter based on the ultrasound imaging signals, and send a quantification signal to the host device over the wireless communications network. The quantification signal may indicate a result of comparing the at least one physiologic parameter with a predetermined threshold. The transducer probe may be self-powered, and include a battery.

In another aspect of the invention, an imaging system for monitoring cardiac status of a patient is provided. The imaging system includes transthoracic transducers affixable to a body of the patient for sending ultrasonic imaging signals into the patient, receiving reflected imaging signals and providing imaging data based on the received imaging signals. The imaging system further includes a transceiver for receiving the imaging data provided by each of the transthoracic transducers and sending the collective imaging data

PCIP.641 over a wireless communications network to a host device, enabling substantially continuous abdominal monitoring of the patient at the host device.

Each of the transthoracic transducers may be affixed to the body of the patient using an adhesive or suction. Also, each of the transthoracic transducers may include an electronically steerable array.

FIG. 1 is a functional block diagram of a representative ultrasound imaging system communicating over a wireless network according to various embodiments.

FIG. 2 is a functional block diagram of a representative transducer according to various embodiments.

FIG. 3 is a functional block diagram of a representative imaging system according to various embodiments.

FIG. 4 is a functional block diagram of a representative ultrasound imaging system including a transesophageal transducer probe according to various embodiments. FIGS. 5 and 5 A are schematic cross-sectional views of a rigid region of the transesophageal transducer probe according to various embodiments.

FIG. 6 is a functional block diagram of a representative ultrasound imaging system including a transthoracic transducer according to various embodiments.

FIG. 7 illustrates a transthoracic transducer patch attached to a patient's body in an area of interest according to various embodiments.

FIGS. 8 A and 8B illustrate shifting ultrasonic images without moving a transthoracic transducer patch according to various embodiments.

FIG. 9 is a diagram illustrating an ultrasound imaging system control panel according to various embodiments.

In the following detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth in order to provide a thorough understanding of an embodiment according to the present teachings. However, it will be apparent to one having ordinary skill in the art having had the benefit of the present disclosure that other embodiments according to the present teachings that depart from the specific details disclosed herein remain within the scope of the appended claims. Moreover, descriptions of well-known devices and methods may be omitted so as to not obscure the description of the example embodiments. Such methods and devices are

PCIP.641 clearly within the scope of the present teachings.

FIG. 1 is a functional block diagram of a wireless ultrasound imaging system 100 communicating over a wireless link or wireless network according to various embodiments. More particularly, FIG. 1 depicts remote transducer system 110 communicating over a wireless network 140 with a host imaging system 150 through respective wireless interfaces. Generally, embodiments of the present invention provide wireless transmission of ultrasound data from the remote transducer system 110 to the host imaging system 150 on a continuous basis, e.g., for viewing and/or measuring various physiologic parameters of the heart. A region of interest of a patient, for example, are scanned to generate two-dimensional (2D) or three-dimensional (3D) data sets, and transmitted wirelessly over the wireless network 140. Further, ultrasound transmit beams and/or control signals may be sent wirelessly from the host imaging system 150 to the remote transducer system 110 over the wireless network 140.

As will be appreciated by those skilled in the art, one or more of the various "parts" shown in FIG. 1 may be physically implemented using a software-controlled microprocessor, hard-wired logic circuits, or a combination thereof. Also, while the parts are functionally segregated in FIG. 1 for explanation purposes, they may be combined variously in any physical implementation.

In various embodiments, the wireless network 140 may be a wireless local area network (WLAN) or a wireless personal area network (WPAN). WLANs and WPANs may operate according to a number of different available standards, including IEEE standards 802.11 (Wi-Fi), 802.15 (Bluetooth) and 802.16 (WiMax), as well as the WiMedia Alliance Ultra- Wideband (UWB) standard. Transmission and reception of signals are performed according to the various standards and protocols of the wireless network 140, such as the WiMedia UWB standard, for example, depending on implementation. Although the wireless network 140 is shown as including only the remote transducer system 110 and the host imaging system 150, it is understood that a variety of devices and networks, such as patient administration systems, servers, databases and the like, may also be included to provide additional patient support. Further, in various embodiments, a single host imaging system 150 may communicate with and control multiple remote transducer systems 110.

As shown in FIG. 1, the remote transducer system 110 includes ultrasound transducer 112, processor 114, transceiver 120, memory 116 and antenna system 118. The

PCIP.641 ultrasound transducer 112 may be any type of ultrasound transducer array capable of emitting ultrasound signals or scanning beams into tissues of a patient, and receiving ultrasound response signals (echoes) reflected back from the tissues or other structures in the patient. FIG. 2 shows a representative embodiment of the ultrasound transducer 112, although it is understood that the transducer 112 may be implemented using other configurations without departing from the spirit or scope of the present disclosure. In the embodiment shown in FIG. 2, the transducer 112 has an ultrasound transducer array 111 including multiple sets of acoustic elements 113-1 through 113-n. In various embodiments, the ultrasound transducer array 111 may be a one-dimensional transducer array for generating 2D images, or a two-dimensional transducer array for generating 3D images, and is configured for low voltage operation. Each set of acoustic elements 113-1 through 113-n may function as transmit and receive acoustic elements for sending and receiving ultrasound signals. Alternatively, a first predetermined subset of acoustic elements may be designated for transmitting and a second predetermined subset of acoustic elements may be designated for receiving ultrasound signals.

Generally, the transducer 112 is connected to transmit and receive beamformers, which apply electrical pulses to the array acoustic elements 113-1 through 113-n of the transducer array 111 in a predetermined timing sequences to generate ultrasound transmit beams. The transmit beams propagate in a predetermined direction from the transducer 112, passing through the body. Acoustic energy from the transmitted beams is reflected back to the ultrasound transducer 112 from tissue structures as pressure pulses with associated acoustic characteristics. The reflected pressure pulses are converted into corresponding radio frequency (RF) signals by receive acoustic elements (which may be transmit acoustic elements operating in receive mode) of the transducer array 111, which are then provided to a receive beamformer. Due to varying distances traveled by the reflected pressure pulses to the individual acoustic elements, the reflected sound waves arrive at the individual acoustic elements at different times. Accordingly, the corresponding RF signals have different phases, for which the receive beamformer compensates.

In the illustrative embodiment of FIG. 2, the sets of acoustic elements 113-1 through 113-n of the transducer array 111 communicate with corresponding sub-array beamformers 115-1 to 115-m, which control transmission and reception of acoustic pulses

PCIP.641 through the acoustic elements 113-1 through 113-n. The sub-array beamformers 115-1 to 115-m provide partial processing of the ultrasound signals, the remainder of the processing being performed at the host imaging system 150, e.g., by beamformer 164 shown in FIG. 3. Use of sub-array beamformers in an ultrasound transducer is described, for example, in U.S. Patent Application Publication No. 2003/0158482 to POLAND et al, published August 21, 2003, the content of which is incorporated by reference herein in its entirety.

However, in various alternative embodiments, the ultrasound transmit beams emitted by the ultrasound transducer array 111 may be generated by transmit beamformers at the host imaging system 150 (i.e., with sub-array beamformers) and transmitted over the wireless network 140, along with control signals. Alternatively, the ultrasound transmit beams may be generated by transmit beamformers at the remote transducer system 110, e.g., in response to activation signals sent from the host imaging system 150.

More particularly, with respect to FIG. 2, during transmission, acoustic pulses are generated from the acoustic elements 113-1 through 113-n into the patient's body, and during reception, echoes from the generated pulses are received by acoustic elements 113-1 through 113-n. The sub-array beamformers 115-1 to 115 -m combine the received pulses and form sub-array summed RF acoustic signals, which are passed to the transceiver 120 for transmission over the wireless network 140 via antenna system 118.

The transceiver 120 includes receiver 122 and transmitter 124, and provides functionality for the remote transducer system 110 to communicate with the host imaging system 150 over the wireless communication network 140 according to the appropriate standard protocols. It is understood that the receiver 122 includes components necessary to receive data in accordance with various wireless protocols, such as the WiMedia UWB standard, including demodulators, demultiplexers, variable gain and low noise amplifiers, and/or filters, etc. It is likewise understood that the transmitter 124 includes components necessary to transmit data in accordance with various wireless protocols, including multiplexers, modulators, variable gain and low noise amplifiers and/or filters, etc. In an illustrative embodiment, a wireless system, such as that described in U.S. Provisional application No. 60/941,400, entitled "Light Weight Wireless Ultrasound Probe," filed June 1, 2007, may be incorporated within the transducer system 110 (as well as the host imaging system 150).

The processor 114 is configured to execute software algorithms, including ultrasound imaging and network communication algorithms of the embodiments described

PCIP.641 herein, in conjunction with memory 116 to provide the functionality of the remote transducer system 110. The network communications may include, for example, software control of antenna system 118, which may be a beam-steering or beam- switching antenna, for example, implemented in the medium access control (MAC) layer. Processor 114 may include its own memory (e.g., nonvolatile memory) for storing executable software code that allows it to perform the various functions of the remote transducer system 110, discussed herein. Alternatively, the executable code may be stored in designated memory locations within memory 116.

The antenna system 118 may include a non-directional or directional antenna system. For example, as stated above, antenna system 118 may be a beam-steering or beam-switching antenna. Accordingly, the antenna system 118 may include multiple antennas, each corresponding to one antenna beam, or antenna system 118 may include a steering antenna or antenna array that can combine multiple different antenna elements to form a beam in different directions. Alternatively, antenna system 118 may be an omnidirectional antenna, such as a dipole antenna, with a good single polarization beam pattern. In an embodiment, the antenna system 118 may include a stub antenna, similar to that of a cell phone, for example. The stub antenna has small profile making it convenient to hold and carry, and reducing the possibility of damage.

The host imaging system 150 of the wireless ultrasound system 100 includes processor 160, transceiver 154, memory 162, antenna system 152 and graphical user interface 170. The host imaging system 150 may be located anywhere within range of the wireless network 140. For example, in alternative embodiments, the host imaging system 150 may be located bedside in the patent's room, or located outside the patient's room in a centralized work station. A centrally located host imaging system 150 enhances monitoring efforts since the attending medical professionals, such as physicians, nurses, patient managers, etc., may continuously observe the patient's status without having to enter the patient's room. Further, the host imaging system 150 may include alarms that are triggered based on various predetermined criteria provided by ultrasound data from the remote transducer system 110. Also, as stated above, the host imaging system 150 may send and/or receive ultrasound signals and data to multiple remote transducer systems 110, so that multiple patients may be continuously monitored at the central location.

In various embodiments, the host imaging system 150 may be incorporated within any type of computing device configured to include a wireless antenna and interface, such

PCIP.641 as a laptop computer, a personal computer, a dedicated ultrasound imaging processor, and the like. For example, the host imaging system 150 may be a portable 3D ultrasound device, as described, for example, in U.S. Patent Application Publication No. 2003/0158482 to POLAND et al, discussed above. The portable 3D ultrasound device may be a hand-held device small enough to be carried to different locations, and continue to be in contact with the remote transducer system 110, as long as it is within range of the wireless network 140.

The processor 160 is configured to execute software algorithms, including ultrasound imaging and network communication algorithms of the embodiments described herein, in conjunction with memory 162 to provide the functionality of the host imaging system 150. The network communications may include, for example, software control of antenna system 152, which may be a beam-steering or beam-switching antenna, for example, implemented in the MAC layer. Processor 114 may include its own memory (e.g., nonvolatile memory) for storing executable software code that allows it to perform the various functions of the host imaging system 150, discussed herein. Alternatively, the executable code may be stored in designated memory locations within memory 162. The transceiver 154 includes receiver 156 and transmitter 158, and provides functionality for the host imaging system 150 to communicate with the remote transducer system 110 over the wireless communication network 140 according to the same standard protocol. It is understood that the receiver 156 includes components necessary to receive data from the transmitter 124 in accordance with various wireless protocols, such as the WiMedia UWB standard, including demodulators, demultiplexers, variable gain and low noise amplifiers, and/or filters, etc. It is likewise understood that the transmitter 158 includes components necessary to transmit data to the receiver 122 in accordance with various wireless protocols, including multiplexers, modulators, variable gain and low noise amplifiers and/or filters, etc.

The processor 160 includes functionality complementary to that of the remote transducer system 110, as shown in FIG. 2, for performing and controlling the ultrasound imaging process. For example, referring to the representative block diagram of FIG. 3, the processor 160 may include (transmit and receive) beamformer 164, image detector 166 and scan converter 168. In the depicted illustrative embodiment, when receiving ultrasound data through the antenna system 152 and the transceiver 154, the beamformer 164 may be provided a stream of digital data through analog-to-digital converters (not shown), and

PCIP.641 performs dynamic beamforming to generate a full array of beamformed RF data. The image detector 166 generates detected acoustic data from the RF data, which is converted into a 2D or 3D image by the scan converter 168.

The 2D or 3D image may be displayed on display 172 of GUI 170. The process may be controlled and/or the image may be manipulated by a user by input commands via the console 174, which may include a keyboard, a mouse, a touch pad, or other input device of the GUI 172.

As discussed above, the antenna system 152 may include a non-directional or directional antenna system. For example, as stated above, antenna system 152 may be a beam-steering or beam-switching antenna. Accordingly, the antenna system 152 may include multiple antennas, each corresponding to one antenna beam, or antenna system 152 may include a steering antenna or antenna array that can combine multiple different antenna elements to form a beam in different directions. Alternatively, antenna system 152 may be an omnidirectional antenna, implemented for example as a dipole antenna. In alternative embodiments, additional functionality may be included in the remote transducer system 110. For example, the beamformer 164, the image detector 166 and/or the scan converter 168 may be included in the remote transducer system 110, requiring additional processing capacity by the processor 114. In this case, image data is transmitted over the wireless network 140 to the host imaging system 150. Therefore, the transceivers 120, 154, the antenna systems 118, 152 and/or the wireless network 140 must be configured to handle greater bandwidths. Also, since the ultrasound signals would be generated locally at the remote transducer system 110, ultrasound signals would not be generated and sent over the wireless network 140 from the host imaging system 150, although control signals would continue to be sent from the host imaging system 150. Further, in addition to beamforming, scan conversion and the like, the transducer system 110 may perform quantification or other processing for monitoring the patient, and send only status signals to the host system 150 via the wireless network 140. The status signal, which may simply indicate acceptable versus unacceptable (pass/fail) conditions of the patient, require very little bandwidth, thus enabling use of a type of wireless network 140 having reduced or minimal capabilities. The quantification process or algorithm is by the processor 114, and may include, for example, measuring flow rates within the heart, detecting rates of change of various physiological parameters, etc. Then, only the "monitoring information" is transmitted by the transmitter 124, e.g., using a relatively

PCIP.641 small bandwidth, over the wireless network 140 to host system 150. The host system 150 may be configured to generate an alarm when the received signal indicates a failing condition, such as a flow rate or other parameter dropping below a predetermined threshold. In a representative embodiment, the wireless ultrasound system may include a TEE or TNE transducer probe that is introduced through the esophagus or nose, respectively, and locked into position in the esophagus or fundus of the stomach for cardiac imaging. The TEE or TNE transducer probe may be self-powered, using a battery or an adapter. In an embodiment, the initial data may be sub-beamformed using technology described, for example, U.S. Patent Application Publication No. 2003/0158482 to POLAND et al, discussed above. The data may then be transmitted to a host imaging system over an UWB radio link, for example.

FIG. 4 is a functional block diagram illustrating a representative wireless ultrasound system 400, including a wireless TEE and/or TNE transducer. The functionality of the ultrasound imaging components may incorporate any ultrasound imaging system, including the TEE and TNE ultrasound imaging systems described, for example, in U.S. Patent No. 6,572,547 to MILLER et al., issued June 3, 2003, the content of which is incorporated herein by reference herein in its entirety.

Referring to FIG. 4, TEE imaging system 400 includes a transesophageal remote transducer probe 410 with a probe handle 414, which may house the components of exemplary remote transducer 110 of FIG. 1, including a transceiver (not shown) and an antenna 418. The remote transducer probe 410 communicates through the antenna 418 with host imaging system 450 over a wireless network, through antenna 452 connected to the host imaging system 450. The host imaging system 450 may include the components of exemplary host imaging system 150 of FIG. 1 in electronics box 420, as well as display 472 and console 474, which interface with a user and the electronics box 420. The electronics box 420 may include, for example, transmit and receive beamformers, image detector and scan converter, as discussed above.

The transesophageal remote transducer probe 410 includes a distal part 430 connected to an elongated semi-flexible body 436. The proximal end of elongated body 436 is connected to a distal end of probe handle 414. The distal part 430 may include a rigid region 432 and a flexible region 434, which is connected to a distal end of the elongated body 436. The probe handle 414 may include a positioning controller 415 for

PCIP.641 articulating the flexible region 434, orienting the rigid region 432 relative to tissue of interest in the patient's body. The elongated body 436 is constructed and arranged for insertion into the esophagus. In an embodiment, the entire insertion tube may be about 110 cm long and has a diameter of about 3OF. Alternatively, the imaging system 400 may use a TNE imaging probe, which includes an insertion tube connected to the distal part 430 with a one-dimensional or two-dimensional transducer array for insertion through the patient's nose. In an embodiment, the nasal insertion tube is about 100 cm to 110 cm long and has a diameter of about 1OF to 2OF. The transducer array may be bonded to an array backing and the individual transducer elements may be connected to an integrated circuit, as discussed with respect to FIGS. 5 and 5 A.

The transducer probe 410 can be made by using a commercially available gastroscope and the distal rigid region 432 shown in FIGS. 5 and 5 A. The gastroscope is made, for example, by Welch Allyn (Skananteles Falls, N.Y.).

Referring to FIGS. 5 and 5 A, the remote transducer probe 410 includes the distal rigid region 432 coupled to the flexible region 434 at coupling region 540. The distal rigid region 432 includes a distal tip housing 550 for encasing an ultrasound transducer array 511, electrical connections and associated electronic elements. The transducer array 511 may be a one-dimensional or two-dimensional array of ultrasound acoustic elements, for generating 2D or 3D images, respectively, as discussed above. The distal tip housing 550 includes a lower tip housing 552 and an upper tip housing 554 having an ultrasonic window 556 and a matching medium located in front of transducer array 511. The front part of tip housing 550 has a bullet shape with a rounded tip (or pill shape) for easy introduction into the fornix and advancement in the esophagus. Furthermore, housing 554 has a convex shape around the ultrasonic window 556. The ultrasonic window 556 may also include an ultrasonic lens and a metal foil embedded in the lens material for cooling purposes.

Transducer array 511 may be bonded to an array backing 560, and individual transducer elements may be connected integrated circuit 562, as described, for example, in U.S. Patent No. 5,267,221 to MILLER et al, issued November 30, 1993, the content of which is incorporated by reference herein in its entirety. The integrated circuit 562 is connected to a circuit board 564 using wire bonds 566. This structure is thermally connected to a heat sink 568. The remote transducer probe 410 may further include two super flex circuits 558 and 558 A, which provide connections between the circuit board 564

PCIP.641 and a transceiver (not shown) for transmitting and receiving data/signals to and from the host imaging system 450. The super flex circuits 558 and 558 A may be arranged to have isotropic bending properties, for example, by folding into an accordion shape or by wrapping into a spiral shape. Alternatively, the super flex circuits 558 and 558 A may be replaced by a coaxial cable.

For continuous monitoring, the TEE or TNE transducer probe should not be kept in pressure contact with the esophagus to prevent necrosis of the tissue. The self-powered monitoring transducer probe will systematically relieve pressure from the esophagus by articulating off of the tissue over periods of time. For example, the transducer probe may automatically articulate off of the wall of the esophagus or fundus of the stomach at times to relieve the pressure on the tissue. This allows for continuous or periodic monitoring at intervals over a longer period of time.

The TEE or TNE transducer probe allows for hands free and wire free cardiac monitoring, for example. The wireless TEE or TNE transducer probe may be positioned by an expert in sonography, while the continuous and/or interval monitoring can be performed by a less skilled worker, such as an ICU nurse, intensivist, etc. This enables improved and more efficient monitoring and care of the patients. In addition, continuous monitoring via wireless TEE or TNE transducer probes dramatically simplifies care of the patient, by eliminating bulky cables. The wireless TEE or TNE transducer probe provides a less intrusive more easily tolerated transesophageal approach than standard TEE or TNE probes having cables attached to a bedside imaging system, thus restricting probe and patient positions. The TEE or TNE transducer probe would also incorporate both manual and electronic articulation control such that remote control of articulation position and pressure could be achieved by an operator or automatically, e.g., at preset internals. In another representative embodiment, the wireless ultrasound system includes a transthoracic transducer, which includes an adhesive or suction patch to fix a transducer probe to the patient's chest or abdomen, enabling substantially continuous abdominal monitoring, for example. The wireless probe would have the ability to scan electronically since it is a 3D probe and transmit the data to a remote ultrasound system, as described, for example, in U.S. Patent No. 5,598,845 to CHANDRARATNA et al, and U.S. Patent Application No. 11/912,588 to PESZYNSKI. FIG. 6 is a functional block diagram illustrating a representative wireless ultrasound system 600, including a wireless transthoracic transducer.

PCIP.641 The wireless transthoracic transducer may be a low profile transducer, since cable, cable attachment and handle are not needed. The chip subassembly of the remote transducer is typically less than one centimeter in thickness, even with packing. It is coupled to the body through by a standoff pad and gel, held in place with any physical mechanisms, e.g., suction, adhesive, etc. The lower profile design and lack of wires makes the remote transducer simpler to place and wear. The wireless nature of the remote transducer also removes the need for bulky ultrasound systems that are dedicated to a single patient and located in the crowded patient room, particularly in an ICU or operating room setting. FIG. 6 is a functional block diagram illustrating a representative wireless ultrasound system 600, including a wireless low profile large aperture matrix array sensor assembly controlled by a phased array ultrasound imaging system, according to an embodiment. Remote transthoracic transducer 610 includes transducer matrix array 611, held captive in a low profile rigid housing 613. The remote transducer 610 may include the components of exemplary remote transducer 110 of FIG. 1 , including a transceiver (not shown) and an antenna 618. The remote transducer 610 may be self-powered, using a battery or an adapter. The transducer array 611 communicates with host imaging system 650 over a wireless network through antenna 618 electrically connected to the transducer array 611 and antenna 652 electrically connected to the host imaging system 650. The host imaging system 650 may include the components of exemplary host imaging system 150 of FIG. 1 in electronics box 620, as well as display 672 and console 674, which interface with a user and the electronics box 620.

The remote transducer 610 may be attachable using a disposable pad, for example, made of suitable low acoustic loss material such as silicon or equivalent, which is attached to the transducer housing 613 and acoustically coupled to the transducer array 611 with ultrasound gel. The remote transducer 610 (and pad) may be attached to a patient's body in the area of interest with adhesive on its perimeter, and is acoustically coupled to the body with ultrasonic gel, as shown in FIG. 7. In alternative embodiments, multiple remote transducers 610 are affixed to the patient to monitor different areas or to provide different views of the same area. For example, multiple remote transducers 610 are useful for cardiac monitoring by locating the pads over standard cardiac imaging windows on the patient's body, such as the suprasternal, parasternal, and subcostal areas. It is understood that this embodiment is not limited to cardiac imaging, but may be used whenever

PCIP.641 placement of multiple remote transducers 610 may be useful, for example, when monitoring a pregnant woman and her fetus. When multiple remote transducers 610 are affixed to a patient, each remote transducer 610 may include a corresponding wireless interface, including a transceiver and an antenna, for individually communicating with the host imaging system 650. Alternatively, the multiple remote transducers 610 may be interconnected by cabling to a single wireless interface, which includes a transceiver and an antenna for exchanging communications with the host imaging system 650 for all of the remote transducers 610.

Images obtainable from the transducer array 611 include both standard 2D phased or linear array formats, as well as 3D real-time volume imaging as described, for example, in U.S. Patent No. 6,679,849 to MILLER et al, issued January 20, 2004, the content of which is incorporated by reference herein in its entirety. The images may be tuned and manipulated electronically from the host imaging system 650. Keyhole imaging may be used, for example, to image between ribs if the transducer array 611 is inadvertently placed over a rib during cardiac imaging. Multiple transducers may be envisioned running on the same system depending upon the clinical imaging requirements at hand.

The low profile transducer array 611 may be a Capacitive Micromachined Ultrasound Transducer (CMUT), as described for example in U.S. Patent No. 6,585,653 to MILLER, issued July 1, 2003, or a Piezoelectric Micromachined Ultrasound Transducer (PMUT), as described for example in U.S. Patent No. 6,659,954 to ROBINSON, issued December 9, 2003, the contents of which are incorporated by reference herein in their entireties. Alternatively, the low profile transducer array 611 may have a micro-machined ultrasound transducer construction or a piezo-based construction, as described for example in U.S. Patent No. 6,679,849. The CMUT may be manufactured using standard integrated circuit processes where capacitively coupled micro-machined drums would create the acoustic beams. An application-specific integrated circuit (ASIC) is integrally fabricated as part of the CMUT. The PMUT may be manufactured using integrated circuit processes where piezoelectric elements would create the acoustic beams. The ASIC may fabricated first, and the piezo material doped afterwards. The transducer array 611 may be attached to the rigid transducer housing 613 using standard techniques. The acoustic interface materials are known in the art. As discussed above, a low loss pad having a thickness sufficient to absorb minor changes in human body contours may be manufactured as a disposable, so that it could be attached to and later

PCIP.641 removed from the transducer housing 613 and applied with acoustic gel to insure good acoustic coupling between transducer and pad. A release film may be applied at the perimeter of the patient to pad adhesive interface. Once the transducer position of interest is determined, acoustic gel may be applied to the pad and the release film removed and the transducer applied to the patient imaging area. Once good acoustic contact is obtained, imaging control may be input at the host system 650 without the need to physically manipulate the transducer array 611.

The imaging system 650 may be a phased array ultrasound imaging system, for example, for controlling the transducer array 611, so that images from the transducer array 611 include both standard 2D phased and linear array formats as well as 3D real-time imaging, as described in U.S. Patent No. 6,679,849, for example. The host imaging system 650 may be any suitable ultrasound imaging system, such as but not limited to Philip's Sonos 7500, for example. The images may be tuned and manipulated electronically from the host imaging system 650. In an illustrative embodiment, the structure of the remote transducer 610, including the transducer array 611, may include a de-matching layer for low profile assembly, as described for example in U.S. Patent No. 6,685,647 to SAVORD et al., issued February 3, 2004, the content of which is incorporated by reference herein in its entirety.

A problem may arise when views of imaging targets are obstructed, for example, by the patient's ribs. However, the obstruction may be avoided without having to mechanically adjust of the remote transducer 610 adhered to the patient's body, using remote operation of the controls on the console 674 of the ultrasound imaging system 650. It is understood that the described embodiment applies equally to obstructions other than rib shadowing, as well. Also, in substantially the same manner, the remote transducer 610 may be positioned over one or more targets to visualize at least one or more targets by repositioning sector scans using the controls on the console 674 of the ultrasound imaging system 650, again, without having to mechanically adjust the remote transducer 610. This makes it possible to visualize multiple targets remotely with the ultrasound imaging system 650. That is, embodiments may be utilized for sector scanning, volume scanning, and elimination of obstructions while imaging and imaging remotely in more than one area of interest of a patient's body.

FIGS. 8 A and 8B depict scanning views that address the problem of image obstruction. As shown in FIG. 8 A, the remote transducer 610, including transducer array

PCIP.641 611, is applied with the acoustic gel to the patient's body, for example, with the acoustic gel applied between the transducer array 611 and the patient. Assuming the patient's ribs 854 block access to acoustic scan lines for imaging target 830, the original 2D sector scan 851 may be repositioned to shifted 2D sector scan 852 from the control console 674 of the host imaging system 650 by utilizing, for example, touch screen keys 954 and trackball 955, shown in FIG. 9.

Referring to FIG. 9, which shows a phased array ultrasound imaging system control panel (e.g., console 674), the trackball 955 may be rotated accordingly to scroll the image, e.g., shown on display 672, to the left or to the right in order to position the image with the rib out of the way. The soft key controls 954 also provide various movement of the image as indicated, such as tilt, elevation, biplane rotate, etc., resulting in an unobstructed view of the image, as indicated in FIG. 8B. The 3D ultrasound system operates in a 2D imaging mode with the transducer array 611 that is positioned over an imaging target and can visualize the image by repositioning sector scanning, e.g., horizontally, using a remote system control at host imaging system 650. As stated previously, the controls on these consoles can be used to image targets having any type of obstruction or for visualizing more than one target, and the present invention is not limited to any one particular use.

According to the various embodiments, by having the wireless ultrasound transducer in-situ during critical situations, the cardiac or other critical function can be carefully and continuously monitored. By having simple image quantification in place, the management of the patient will be improved. For example, the reduction in cardiac output has been shown to be a good indicator of whether the patient is getting sepsis. There is about a six hour window critical to determining proper treatment. If the sepsis is caught early enough, the patient will do better. By having a wireless ultrasound transducer in place, the nurse or patient manager is able to monitor the cardiac output during the critical time period. As stated earlier, by having the ultrasound transducer link wirelessly to a host, this increases the flexibility of the ultrasound system. It can be brought into the room on occasion or integrated into the monitoring system. The wireless transducers may be useful in several disciplines, including cardiology, OBGYN and radiology, for example. While illustrative embodiments are disclosed herein, many variations are possible which remain within the concept and scope of the invention. Such variations would become clear to one of ordinary skill in the art after inspection of the specification, drawings and claims herein. The invention therefore is not to be restricted except within

PCIP.641 the spirit and scope of the appended claims.

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Claims

CLAIMSWhat is claimed is:

1. A monitoring system, comprising: a transesophageal echocardiogram (TEE) ultrasound transducer probe for receiving ultrasonic imaging signals reflected from a target object and providing imaging data based on the received imagining signals; and a wireless interface for communicating the imaging data over a wireless communications network to a host device.

2. The monitoring system of claim 1, wherein the wireless communications network comprises an Ultra- Wideband (UWB) standard network.

3. The monitoring system of claim 2, wherein the transceiver continuously sends the imaging data over the wireless communications network to the host device for continuous monitoring of the target object.

4. The monitoring system of claim 3, wherein the host device comprises an image generator generates at least one image to be displayed on an image display based on the imaging data.

5. The monitoring system of claim 4, wherein the host device dedicated to the transducer and is located in proximity to a patient being monitored by the transducer.

6. The monitoring system of claim 6, wherein the host device is located in centralized monitoring station remote from a patient being monitored by the transducer, and is configured to receive additional imaging data from at least one other transducer.

7. The monitoring system of claim 2, wherein the transducer comprises a one- dimensional array for creating a two-dimensional image based on the imaging data.

8. The monitoring system of claim 2, wherein the transducer comprises a two- dimensional array for creating a three-dimensional image based on the imaging data.

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9. The monitoring system of claim 2, wherein the host device comprises a laptop computer.

10. The monitoring system of claim 1, wherein the transducer comprises a transnasal TEE (TNE) ultrasound transducer probe.

11. The monitoring system of claim 10, wherein the transducer is locked into position in one of an esophagus or a stomach fundus of a patient being monitored by the transducer for cardiac imaging of the patient.

12. The monitoring system of claim 11 , wherein the transducer comprises a distal tip, which automatically periodically articulates away from the esophagus or the stomach fundus to prevent tissue necrosis.

13. An imaging system for monitoring a patient, comprising: a transesophageal echocardiogram (TEE) ultrasound transducer probe, insertable in the patient being monitored and contacting tissue within the patient, for sending ultrasonic imaging signals into the patient, receiving reflected imaging signals and providing imaging data based on the received imaging signals, the TEE ultrasound transducer probe comprising a distal tip configured to periodically articulate away from the tissue to prevent tissue necrosis; and a transceiver for sending the imaging data over a wireless communications network to a host device, enabling substantially continuous monitoring of the patient at the host device.

14. The monitoring system of claim 13, wherein the transceiver receives the ultrasound imaging signals and control signals from the host device over the wireless communications network.

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15. The monitoring system of claim 13, wherein the transducer probe generates the ultrasound imaging signals, and sends imaging data based on the ultrasound imaging signals to the host device over the wireless communications network.

16. The monitoring system of claim 13, wherein the transducer probe generates the ultrasound imaging signals, performs quantification of at least one physiologic parameter based on the ultrasound imaging signals, and sends a quantification signal to the host device over the wireless communications network, the quantification signal indicating a result of comparing the at least one physiologic parameter with a predetermined threshold.

17. The monitoring system of claim 13, wherein the transducer probe is self- powered, and comprises a battery.

18. An imaging system for monitoring cardiac status of a patient, comprising: a plurality of transthoracic transducers affixable to a body of the patient for sending ultrasonic imaging signals into the patient, receiving reflected imaging signals and providing imaging data based on the received imaging signals; and a transceiver for receiving the imaging data provided by each of the plurality of transthoracic transducers and sending the collective imaging data over a wireless communications network to a host device, enabling substantially continuous abdominal monitoring of the patient at the host device.

19. The imaging system of claim 18, wherein each of the plurality of transthoracic transducers affix to the body of the patient using one of an adhesive or suction.

20. The imaging system of claim 19, wherein each of the plurality of transthoracic transducers comprises an electronically steerable array.

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