Patent Application
20060058655
This disclosure relates to ultrasound devices and more particularly to such devices having a thin wire interface.
Ultrasound medical devices are becoming more common. Their typical implementation has the transducer portion separate from the main processing unit of the device. Traditionally, the analog and digital signal processing of the raw ultrasound signals to/from a patient are performed in a main processing unit. The raw ultrasound signals are passed to/from the scanhead transducer across a cable to the main processing unit. The cable that connects the ultrasound transducer with the main body of the ultrasound processing unit must be fairly long because the processing unit is not easily moveable and the scanhead must be placed on the anatomy of interest in a variety of positions. The cable is also typically large and heavy because it carries the transmit and receive signals for a number of individual elements of the transducers, located in the transducer head. The length usually in excess of six feet, coupled with the weight of the cable places significant stress and strain on a sonographer. The cable also adds significant cost and complexity to the system. A typical ultrasound device is shown in U.S. Pat. No. 5,772,412 dated Mar. 3, 1998 and U.S. Pat. No. 6,471,651 dated Oct. 29, 2002 which patent is hereby incorporated by reference herein.
Another problem with existing cables is that they typically contain a large number of individual coaxial cables that are expensive and difficult to connect to a single connector. A connector is typically required on the cable since multiple tranducers are used on the system for different applications. The connector, due to the large number of interconnect lines and the sensitive nature of the signals, is therefore large, complicated and expensive. Thus, the overall cable is expensive, troublesome to assemble and repair as well as difficult to use.
The reason for multiple cables is that the individual elements of the transducers are individually excited with electronic wave forms so as to generate mechanical movement of the transducer elements thereby creating ultrasound energy which is then transmitted to the patient's body. The reflected energy from internal organs (and other items of interest) comes back to the transducer elements and is converted back to electrical signals for subsequent processing by the processing unit. The signal between the transducer and the processor unit must pass without significant distortion, attenuation or interference up and down the connecting cable.
The present invention is directed to an ultrasound system and method which, in one embodiment, partitions the main body processing such that a portion of the processing is contained within the transducer thereby reducing the need for a multiplicity of high performance cables running between the transducer and the main body. This is possible through the use of a unique architecture to allow for proper power management given the small transducer size and an architecture that exploits the high levels of integration possible on integrated circuit technologies allowing for its implementation in a few highly integrated circuits with virtually no external components outside of the ICs.
In one embodiment, the transducer processing consists of transmitters, receivers, and the beam formers necessary to control and generate the beam formed ultrasound signal. By partitioning the system in this manner the output of the scanhead now becomes a digital data stream. All the sensitive analog signals are maintained in close proximity to their transmitters receivers and transducer elements thereby eliminating any significant signal degradation allowing increased performance. The digital data stream can also be converted to a serial high-speed bit stream to further reduce signal count across the interface. The result is a cable and connector having an extremely low signal count. Also, the signals on the cable are digital and, therefore, the cable does not require as high a fidelity, thereby further reducing the cost and size of the cable and connector.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized that such equivalent constructions do not depart from the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
In this arrangement, cable 18 contains a high number of individual signals, typically carried on coax cables, usually in the order of 128 or 256 to carry the analog signals from transducer array 17 back and forth between receiving and transmit channels 12-IT, 12-IR to 12-NT, 12-NR. As discussed above, cable 18 is big, bulky, heavy, expensive and not very efficient. The analog signals are also sensitive, often requiring tuning to try to compensate for the loading of the cable.
In addition to cable size reduction, this rearrangement of elements also results in a performance gain. By eliminating cable 18 analog loading, distortion and attenuation characteristics are also eliminated allowing for increased performance and signal integrity. Better sensitivity, better response, and better bandwidth are achieved. In addition, this arrangement reduces power loss of the transmitters on the cable.
Cable 25 (or 33) is preferably a pair of Low Voltage Differential Signal (LVDS) lines to transmit the digital data back and forth. Also, a USB or USB2, or IEEE1394 type interface could also be used using USB on other now standard interface could be used. This interface could also be replaced with a wireless interface, if desired. However, for wireless given the present transmission bandwidths available it would be better to move additional DSP functions to the transducer as well, thereby even further reducing the data bandwidth required.
As shown in
In a preferred embodiment, DBF 23, DSP 13 and BE 14 would be implemented using digital CMOS ASICS and digital/analog mixed-mode ASICS and Tx/Rx 26 would be implemented based on high-voltage and/or Bi-Cmos technology. The total weight of the scanhead module of one embodiment is less than 12 ounces. Excluding the housing, transducer 17, in one embodiment, weighs less than 8 ounces. The peak power consumption is approximately 6 watts. Average power consumption with power management is less than 4 watts and the bandwidth of the signals over the interface from the transducer to the processing unit, has been reduced at least on order of magnitude from approximately 400 Mbps to under 40 Mbps. In one embodiment, for a video display having 128×512 pixels, a data rate of 16 Mbps is possible using the concepts discussed herein.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
The present application is related to co-pending, and commonly-assigned U.S. patent application Attorney Docket No. 65744/P017US/10404216, entitled “Ultra System Power Management,” filed concurrently herewith U.S. patent application Ser. No. 10/847,643, filed on May 17, 2004, entitled “Processing Of Medical Signals;” U.S. patent application Ser. No. 10/821,123, filed on Apr. 8, 2004, entitled “Systems And Methods For Providing ASICS For Use In Multiple Applications;” U.S. patent application Ser. No. 10/821,198, filed on Apr. 8, 2004, entitled “System And Method For Enhancing Gray Scale Output On A Color Display;” the disclosures of which are all hereby incorporated.
