WO2000024318A1

WO2000024318A1 - Catheter parameter storage and transmission

Info

Publication number: WO2000024318A1
Application number: PCT/EP1999/008070
Authority: WO
Inventors: Donald Masters
Original assignee: Boston Scientific Limited
Priority date: 1998-10-27
Filing date: 1999-10-26
Publication date: 2000-05-04

Abstract

A catheter or other medical device (15) carries an information retention device that transmits or receives and transmits information acquired during catheter manufacturing or use. The catheter (10) can be an imaging catheter coupled to an imaging system (12) where the stored manufacturing parameters are read and compensations are made for deviations from ideal parameters to improve imaging. Alternately, the catheter can be connected to a diagnostic apparatus to analyze usage and failure modes and retained scanned images. Methods of use are also described.

Description

DESCRIPTION

Catheter Parameter Storage And Transmission

Field Of Invention

The invention generally relates to catheters carrying information retention devices that can be coupled to imaging systems and catheter diagnostic units and methods of their use. In a more specific sense, the invention relates to acoustic imaging systems and ultrasound catheters and especially to methods for improving imaging and diagnosing failure mechanisms of catheters. The devices include catheters that have readable rewritable nonvolatile programmable information retention devices that can receive and transmit information acquired during catheter manufacturing and use. In general, stored manufacturing information can be used to standardize the output of medical devices. This manufacturing information and the information acquired during use can also be used to optimize imaging or to track and diagnose failure mechanisms. The devices herein are particularly suited for intravascular ultrasound imaging.

Background

Various apparatus and methods for intravascular ultrasound imaging have been known and used in the past. Ultrasound imaging catheters coupled to motor drives and imaging systems are well known. See Yock, U.S. Pat. No 5,000,185 for a description of an imaging catheter, the disclosure of which is incorporated herein by reference. By rotating the image element, a real time ultrasound image in the plane perpendicular to the vessel can be obtained. The image created is 360° view of a particular region of the interior wall of the vessel. The view can be further enhanced by moving the entire rotating catheter in the longitudinal direction so that a two-dimensional cross-section or a three- dimensional view of the interior of the artery can be formed. There are a wide variety of catheter types, frequencies and configurations. As a result, the imaging apparatus to which the catheters are coupled typically must be manually adjusted to each type of catheter in order to obtain the proper image quality. Adjustments to image size, gain, frequency, rate of rotation, transmit power, and the like, are made by inputting specific data regarding the catheter type. Such manual input does not fully optimize performance of the system.

More recently, certain catheters having the capability to store limited information about catheter type have been described. One device uses a 4-bit signal, and is therefore limited to identification of a maximum of 16 different catheter types. See Brisken, et al., U.S. Pat. No. 5,209,235, the disclosure of which is incorporated herein by reference. Although additional signal terminals could be added to this device, there is a functional limit to the amount of data that can be stored, and thus the application is limited to detecting only certain categories of catheter information. Further, the device has no write capability and also requires a direct contact between the catheter and the rest of the imaging system thus requiring conventional patient isolation methods.

Information storage devices have also been used in ablation catheters, again to store a catheter identification code that identifies and locks out catheters that are not suited for the apparatus and also prevents reuse. See Jackson, et al., U.S. Pat. No. 5,383,874, the disclosure of which is incorporated herein by reference. Again, this catheter has direct electrical contact with the rest of the control system.

In other applications, information storage devices have been used to store a record of the number of times a medical device has been used to determine whether the device is within warranty. See Chin, et al., U.S. Pat. No. 5,425,375, the disclosure of which is incorporated herein by reference. This catheter tracks usage by means of a temperature sensor to detect the number of sterilizations to which the catheter has been subjected and records this number in the storage device.

In addition to catheter identification and number of uses, there are other types of information that would be useful to store in a catheter if the information retention device had write, and in some cases rewrite, capability and sufficient memory. For instance, there are catheter to catheter differences that result from manufacturing variations during production. While the imaging apparatus can be adjusted to optimize imaging for a specific catheter type, there is presently no way to automatically compensate for these manufacturing variations. Accordingly, there is a need for a catheter that can receive and store information about its manufacturing parameters in a form readable by an imaging apparatus so that catheter parameters that vary from an ideal standard can be compensated for by the apparatus. There is also a need for a catheter with a rewritable storage device that can receive and store information acquired during catheter use in a form readable by a catheter diagnostic apparatus. Information such as time and duration of use, failure mechanisms, patient and hospital identification, performance deviations from standard scanned images, and the like, could be stored by the catheter and subsequently read by the diagnostic apparatus. Retrieval of such information could assist catheter designers and manufacturers in continuous quality improvement of the product. The quantity of information necessary for such applications requires a memory device with a vastly larger storage capacity than most of the devices currently in use. Further, the device must have write capability, preferably be erasable, nonvolatile and have rewrite capability and most preferably be electronically erasable and suitable for in- circuit programming. There is also a need for faster data transfer and for more advanced methods of electrically isolating the patient from the system electronics.

Summary Of The Invention

It is an object of the present invention to standardize the output of medical devices where deviations from standard have been created by manufacturing variability in the medical device. It is more particularly an object of the present invention to reduce the contribution to image distortion created by manufacturing variability in an imaging catheter. It is a further object to provide two-way communication and nonvolatile storage of large amounts of information in the catheter. Other objects are to provide wireless communication of information between the catheter and the rest of the system to provide a more complete patient isolation method and to store information acquired during catheter use for later diagnostic analysis. One embodiment is an imaging catheter that includes a catheter body, a functional imaging component, for example a transducer, and an information retention device carried by the catheter body, where the device carries stored information and transmits the information when prompted by an external reader. The information retention device is operably connectable to an imaging apparatus and to a catheter diagnostic unit, each of which are capable of reading the information stored in the device.

In certain embodiments, the stored information can be information acquired during catheter manufacturing that uniquely identifies the operating characteristics of the imaging component. In other embodiments where the device is a readable rewritable programmable information retention device, the stored information is information acquired during catheter use.

Another embodiment is imaging system that includes a catheter of the type previously mentioned and an imaging apparatus that has a reader capable of reading the information stored in the information retention device. The imaging apparatus also operates and controls the operation of the functional imaging component of the catheter. The apparatus receives detected feature information from the component and uses the information to produce images. In one embodiment, the imaging system stores a set of ideal catheter parameters and compares those parameters to the manufacturing parameters that it reads from the information retention device.

Methods of use are also described. An embodiment of a method of producing an image with an imaging system includes the steps of writing and storing catheter parameter information in the catheter information retention device. In certain embodiments, this step is performed during manufacturing. The stored information is then read by the imaging apparatus and compared to an ideal set of parameters stored in the apparatus. A set of operating instructions is created to compensate for deviations in catheter parameters from the ideal set and the imaging apparatus is then adjusted based on the operating instructions. An anatomical area having a feature is then scanned with the functional component to detect the feature, and the feature information is sent to the imaging apparatus that produces the image.

In other embodiments, this comparative method is used to standardize the output of a medical device that has an information retention device and a functional component having an output and a control apparatus operably connected to the functional component and to the information retention device. The control apparatus has a stored set of ideal parameters for the medical device. Medical device parameter information acquired during manufacturing of the device is written to and stored in the information retention device. The control apparatus then reads the information and compares it to the ideal set. It then creates a set of operating instructions to compensate for deviations in the actual medical device parameters from the ideal set and adjusts the control apparatus based on the operating instructions. The output of the functional component is thus standardized by the control apparatus. This standardization method can be used not only for imaging catheters, but for other types of medical devices, for example ablation catheters.

Another embodiment is a method for diagnosing catheter failure mechanisms in a catheter having a functional component and a readable rewritable programmable information retention device. First the functional component is used on an anatomical area of a patient. Information acquired during catheter use is stored in the information retention device of the catheter. Then the stored information is read to diagnose catheter failure mechanisms. In certain embodiments, the diagnostic apparatus is a separate unit from the control apparatus. In these embodiments, the information retention device is nonvolatile, allowing the catheter to be disconnected from the control apparatus after use and operably connected to the diagnostic apparatus where the step of reading the stored information is performed.

Brief Description Of The Drawings

FIG. 1 depicts a schematic view of an imaging catheter with an information retention device.

FIG. 2 depicts a schematic view of an imaging system that includes a motor drive unit in direct contact with the catheter of FIG. 1. FIG. 2A depicts a schematic view of a patient isolation method using an isolation transformer.

FIG. 2B depicts a schematic view of a patient isolation method using a wireless RF link. FIG. 3 depicts a schematic view of an imaging catheter coupled to a catheter diagnostic apparatus.

FIG. 4 depicts a schematic view of an imaging catheter with an information retention device and serial communication capability.

FIG. 5 depicts a schematic view of an imaging system that includes a motor drive unit serially coupled to the catheter of FIG. 4.

Detailed Description

While the following detailed description is directed to a preferred embodiment of a catheter, the scope described herein is not limited to catheters, but may be equally appropriate to other medical devices as well, for example, minimally invasive probes. As shown in FIG. 1, an imaging catheter 10 includes a catheter body 11 carrying a functional imaging component 12 and an information retention device ("catheter chip") 15. The imaging component 12 is operably connectable to an imaging apparatus that controls the operation of the component and also controls the operation of an image producing device, hereinafter described. The catheter chip 15 can also be operably connectable to an imaging apparatus.

The catheter chip 15 is adapted to receive and store information and to transmit that information when prompted by an external reader. In certain embodiments, this information is catheter parameter information acquired during catheter manufacturing that uniquely identifies the operating characteristics of the imaging component. Where the catheter is an ultrasound imaging catheter and the functional imaging component is a transducer, this information typically consists of acoustical electronic parameters written to and stored in the device either during manufacturing or thereafter for subsequent reading by the imaging apparatus. The imaging apparatus then compares the catheter manufactπiring parameters to an ideal set of parameters stored in the imaging system and compensatorily adjusts the operation of the functional imaging component to enhance imaging. Such parameter information can include transducer gain, transducer center frequency, transducer beam pattern, transducer transfer function, transducer impulse response, transducer band width sheath artifact amplitude, optical transparency of cable sheaths and the like. For such applications, the information retention device need only be a one time programmable ("OTP") device, such as a read-only memory ("ROM") although more sophisticated devices will work, as well.

Where the catheter chip 15 is used to store information acquired during catheter use, the information retention device must be a readable rewritable programmable device to allow in-circuit programming. OTP devices are thus not suitable for this type of prograirvrning. The stored information can later be read by a catheter diagnostic apparatus. Such information can include time and duration of use of the catheter, failure mechanisms during use, hospital identification, patient identification, catheter performance deviations from standard, scanned images and the like. In a preferred embodiment, the functional component is a functional imaging component such as a transducer used in ultrasound imaging and more preferably, intravascular ultrasound imaging. The transducer can be a piezoelectric crystal, such as PZT crystal, or an organic electret, such as polyvinylidine fluoride, polyvinylidine difluoride, or the like, or any composite piezoelectric material. In the ultrasound application, certain embodiments are part of an imaging system (hereinafter described) that also includes a motor drive unit ("MDU") 30 as shown in FIG. 2. The MDU 30 interfaces with the proximal end of the catheter 10 to provide rotational and translational movement for the transducer and electrical connection to the transducer leads. The MDU rotates the transducer creating a real time ultrasound image in the plane perpendicular to the vessel. By moving the entire catheter in the longitudinal direction, a two-dimensional cross-section as well as a three-dimensional view of an artery can be formed. The catheter can be operated over a standard interventional guide wire that runs through the approximate center of the catheter and the MDU. Details of the catheter and imaging apparatus are provided in Jang, U.S. Patent No. 5,383,460, the disclosure of which is incorporated herein by reference.

In some embodiments, the catheter chip 15 is an electronic storage device with two-way communication capability. Although OTP devices lacking rewrite capability are functional for certain applications, preferable devices include nonvolatile in-circuit programmable devices with rewrite capability such as electrically-erasable programmable read-only memories ("EEPROMs") nonvolatile random access memories ("NVRAMs") and flash memory devices. Certain embodiments include I²C with EEPROM or RF with EEPROM. An example of the latter EEPROM for use in electronic read/write transponders is the 1 kBit device supplied by EM Microelectronic-Marin SA. A 1 kBit device is particularly useful, because the chip must be capable of storing the large amounts of data generated during manufacturing. Certain embodiments have storage ranges as low a 4 bits, which is minimally functional for catheter identification, and as high as 4 megabits or higher. Preferably, the device would store V* to 2 megabits of data, and most preferable, V₂ to 1 megabit.

Figure 4 depicts a catheter 10 having a chip 15 with serial communication, the contacts 16 of which are shown. An example of a serial communication chip is the DS620x CyberKey series supplied by Dallas Semiconductor, certain of which have a 3- wire serial interface. Figure 5 shows the catheter 10 of FIG. 4 in an imaging system 18 that includes an MDU 30 and contacts 35 between the MDU and the catheter chip.

FIG. 2 depicts an imaging system 18 including the catheter 10 of FIG. 1 which includes a functional imaging component 12 and a catheter chip 15 and an imaging apparatus 20 for operably connected to the chip. The apparatus 20 has a reader capable of reading the information stored in the catheter chip. The imaging system 18 also operates and controls the operation of the functional component 12 of the catheter, controls an MDU, if present, and receives the detected feature information from the component 12. The system 18 uses this feature information to produce images. Although FIG. 2 includes an MDU 30 connecting the catheter 10 to the imaging apparatus 20, in some embodiments, the catheter 10 is directly connected to the imaging apparatus 20. The imaging apparatus 20 includes a signal processing unit ("SPU") 26 that is adapted to store a set of ideal parameters and compare those parameters to the catheter parameters, and an image producing device ("IPD") 27. Certain embodiments also include a display unit and in some embodiments, this display unit includes a video processor and a monitor 25. During use, the catheter parameter information stored by the catheter chip 15 is transmitted to the SPU 26. The SPU 26 compares this information to a stored set of ideal parameters and compensatorialy adjusts the operation of the functional imaging component 12, and sends output video signals that enhance the image produced by the IPD 27. In another embodiment, the enhanced feature signals are sent directly to the IPD by the functional imaging component. Also, any information acquired during use is written to and stored in readable form in the catheter chip 15. While the embodiment of the imaging apparatus shown in FIG. 2 includes an SPU 26 housed in the imaging apparatus 20, in other embodiments, the SPU 26 is housed in the MDU 20 or in the catheter 10. Within the SPU 26 is an ultrasound pulser and a receiver for respectively generating and receiving ultrasound signals from the transducer. The echo pattern from the transducer is passed back to the signal processor receiver, where the signal is detected and converted to digital form by the A/D converter. The digital signal passes to a memory unit and then to the D/A converter and on to the video processor and monitor. The MDU 30 shown in FIG. 2 is operably connected to the imaging apparatus 20 and to the catheter 10. The embodiment of the MDU 30 shown in FIG. 2 has its own communication device 31 that is operably connected to the to the SPU 26. When the MDU is coupled to the catheter 10, the MDU communication device 31 is operably connected to the catheter chip 15. The catheter chip 15 then uses one serial line of the MDU device 31 to transmit data to the SPU 26. In embodiments where the imaging system is an ultrasound imaging system, the system further includes a patient isolation device to isolate the patient from the system electronics. In some embodiments, where there is a direct connection between the catheter chip 15 and the MDU communication device 31, as shown in FIG. 2A, the patient isolation device is an isolation transformer 19 operably coupled to the MDU device and to the SPU 26. In another embodiment, shown in FIG. 2B, both the catheter chip 15 and the MDU device 31 are each operably coupled to a radio frequency ("RF") transmitter/receiver. This two-way RF link acts as a patient isolation method, and therefore no isolation transformer is needed. For RF transmission to effectively occur, any materials, such as MDU or catheter housing occupying the area that is in the direct line of RF transmission 17 must be RF transparent. The RF link also permits wireless data transmission to and from the catheter chip 15.

As stated previously, one of the functions of the catheter chip is to receive and store catheter parameter information generated during the manufacturing of the catheter in order to compensate for catheter variations and improve image quality. A method for producing an image with an imaging system is therefore described that includes the steps of first providing the previously described imaging system, and writing and storing catheter parameter information in the catheter chip. As described previously, this step can occur directly during manufacturing or at a subsequent time. Prior to imaging, the catheter parameter information is read by the imaging apparatus, and more particularly, the SPU. The SPU compares this information to the ideal set of parameters stored in the imaging apparatus and then creates a set of operating instructions to compensate for deviations in catheter parameters from the ideal set. The imaging apparatus is then adjusted based on these operating instructions. The functional imaging component then scans an anatomical area having a feature to detect the feature and sends the feature information to the imaging apparatus, and more particularly, to the IPD. An image is then produced with the imaging apparatus. This image is enhanced by the method of compensating for manufacturing variations and thereby standardizing catheter performance.

Certain details of image enhancement techniques using specific examples are set forth below. Ultrasound imaging systems typically use B-mode displays which represent the ultrasound echoes reflected from the scanned area at various brightness or gray scale levels corresponding to the amplitude of the reflected wave. In an ideal environment, the amplitude of the reflected echo would entirely be a function of the measurement of the differences in acoustic impedance of the area of the patient scanned. Instead however, variations in the thickness and composition of the disk that forms the transducer head, lack of absolute transparency in the sheaths surrounding the catheter drive cable and transducer leads, the integrity of the mounting of the transducer supporting ring and the size of the conductive epoxy dot that electrically couples the transducer to the transducer leads all affect parameters that control the amplitude of the reflected echo, and thus image quality. These compositional, physical and electrical manufacturing variations can affect catheter parameters including transducer gain, transducer center frequency, transducer beam pattern, transducer transfer function, transducer impulse response, transducer band width sheath artifact amplitude, optical transparency of cable sheaths and the like.

For example, the goal in controlling transducer gain is to get the same brightness on the monitor every time. Transducer gain results from the pulse-echo response. The transducer sends out a pulse at a certain amplitude, and the received signal voltage is the gain of the transducer. This gain varies from transducer to transducer, sometimes as much as two-fold due to variations in the fabrication of the piezoelectric disk that forms the transducer head. The gain is also a function of the strength of the signal. However in the imaging enhancing embodiment described herein, the SPU reads data from the catheter chip that describes the transducer parameters that control gain, and the SPU compensates by adjusting the strength of the signal to the transducer to produce a uniform brightness from transducer to transducer.

The goal in controlling transducer center frequency is to improve the signal to noise ratio. Each transducer has a natural resonant frequency that is affected by the mounting in the transducer head supporting ring and the thickness and composition of the transducer. By receiving the manufacturing data regarding transducer center frequency, the SPU can compensate by adjusting the RF band pass to accommodate for individual variations.

The goal of transducer beam pattern control is to improve lateral resolution. Similarly, the goal of transducer impulse response is to improve axial resolution. Transducer impulse response occurs when the pressure wave that is created when the acoustical wave reflects off an object returns to contact the transducer. The impulse response is a function of how fast the transducer bends and converts the impulse into electrical voltage. The speed of this response varies from transducer to transducer. Compensation of the variations in speed can produce more consistent axial resolution from transducer to transducer. Another example of compensation for manufacturing variations is removal of sheath artifacts that result in bright rings at the center of the image. The rings are caused by variations in optical transparency in the sheaths surrounding the drive wires and transducer leads that run from the MDU through the catheter body and connect with the transducer. Ideally, the sheaths should be optically transparent, however variations in manufacturing produce some degree of optical opacity. By identifying the exact diameter of the particular sheath and its relative transparency during manufacturing and storing this information on the catheter chip, the signal processing unit can subtract out the amplitude and distance of the opacity and remove the artifact from the image produced. Similarly, the manufacturing parameters that affect transducer transfer function can be controlled to improve gray scale resolution.

Standardizing devices by compensating for manufacturing variations can be used in other applications. One embodiment is a method for standardizing the output of a medical device that has an information retention device ("device chip") and a functional component having an output and a control apparatus operably connected to the functional component and to the device chip. The control apparatus has a set a ideal medical device parameters stored in it. Actual medical device parameters acquired during device manufacturing are written to the device chip. The control apparatus reads these manufacturing parameters and compares them to the ideal set and creates a set of operating instructions to compensate for deviations in manufacturing parameters from the ideal. The control apparatus is then adjusted based on the operating instructions and the output of the functional component of the medical device is thus standardized. The standardized functional component of the medical device may then be used on an anatomical area of a patient. In addition to storing information that can be used to enhance image quality or to otherwise standardize output of a medical device, the catheter chip can be used to store information acquired during catheter use. Such information includes time and duration of use of the catheter, failure mechanisms during use, hospital identification, patient identification, scanned images and catheter performance deviations from standard. In some embodiments, the imaging apparatus has write capability and performs the step of writing to the catheter chip. In certain of these embodiments, the imaging apparatus has a user interface allowing a user to enter information which the imaging apparatus then writes to the catheter chip. This information has a variety of uses. As an example, certain catheters may be limited in their ability to be reused due, for instance, to septic problems resulting from attempts to resterilze the units. By tracking catheter usage in the catheter chip, the usage information can be read by the imaging apparatus to signal or disallow unauthorized reuse. Other information is useful in diagnosing failure analysis if catheters are returned to the manufacturer. For instance, scanned images stored in the catheter can be accessed by a diagnostic apparatus at the manufacturer to determine how the catheter functioned during use. An embodiment of a method for diagnosing catheter failure mechanisms first includes the step of using the functional component of a catheter on an anatomical area of a patient. In some embodiments, the catheter is an imaging catheter. In other embodiments, the catheter is an ablation catheter or some other type. Information acquired during this catheter use is stored in the catheter chip which is a readable rewritable programmable device. The stored information is then read to diagnose catheter failure mechanisms. Certain embodiments include the step of operably connecting the catheter to a control apparatus that reads the stored information. Some embodiments include the step of operably connecting the catheter to a diagnostic apparatus that reads the stored information. In certain embodiments, the catheter chip is nonvolatile, and the method further includes operably connecting the catheter to the control apparatus, using the catheter as previously described and storing information acquired during use, disconnecting the catheter from the control apparatus and operably connecting the catheter to the diagnostic apparatus that reads the stored information. The diagnostic apparatus may be located distant from the point of catheter use. The nonvolatile catheter chip allows the catheter to be disconnected from the control apparatus while still retaining the stored information during transit of the catheter to the location of the diagnostic apparatus.

Information such as patient and hospital identification can be input by the user, and other information such as time and duration usage, any failure analysis data and scanned images to be viewed later can be detected by the system while the catheter is coupled to the imaging apparatus and stored directly on the chip. In certain embodiments the control system writes the information to the catheter chip. In some embodiments, the diagnostic apparatus stores the data received from each catheter for subsequent statistical analysis that can be used to optimize manufacturing processes for continuous quality improvement.

While particular devices and methods have been described for catheters and control systems, once this description is known, it will be apparent to those of ordinary skill in the art that other embodiments and alternative steps are also possible without departing from the spirit and scope of the invention. Moreover, it will be apparent that certain features of each embodiment as well as features disclosed in each reference incorporated herein, can be used in combination with devices illustrated in other embodiments. Accordingly, the above description should be construed as illustrative, and not in a limiting sense, the scope of the invention being defined by the following claims.

Claims

1. An imaging catheter comprising: a catheter body; a functional imaging component carried by the catheter body, the functional component operably connectable to an imaging apparatus; and an information retention device carried by the catheter body, the device carrying stored information and transmitting the information when prompted by an external reader.

2. The imaging catheter of claim 1, wherein the stored information is catheter parameter information acquired during catheter manufacturing that uniquely identifies the operating characteristics of the imaging component.

3. The imaging catheter of claim 1, wherein the information retention device is operably connectable to the imaging apparatus.

4. The imaging catheter of claim 1, wherein the information retention device is operably connectable to a catheter diagnostic unit.

5. The imaging catheter of claim 2, wherein the functional imaging component is a transducer and the catheter is an ultrasound imaging catheter.

6. The imaging catheter of claim 2, wherein the information retention device is an electronic information retention device.

7. The imaging catheter of claim 6, wherein the information retention device is a ROM.

8. The imaging catheter of claim 5, wherein the catheter parameters acquired during manufacturing are selected from the group consisting of transducer gain, transducer center frequency, transducer band width, transducer beam pattern, transducer transfer function, transducer impulse response, sheath artifact amplitude and optical transparency of sheaths.

9. The imaging catheter of claim 1, wherein the information retention device is a readable rewritable nonvolatile programmable information retention device storing information written to it and transmitting the information when prompted by an external reader.

10. The imaging catheter of claim 9, wherein the stored information is information acquired during catheter use.

11. The imaging catheter of claim 9, wherein the stored information is catheter parameter information acquired during manufacturing that uniquely identifies the operating characteristics of the imaging component.

12. The imaging catheter of claim 11, wherein the catheter parameter information acquired during manufacturing is written to the information retention device during manufacturing.

13. The imaging catheter of claim 9, wherein the catheter is an ultrasound imaging catheter and the functional imaging component is a transducer.

14. The imaging catheter of claim 9, wherein the information retention device is an electronic information retention device.

15. The imaging catheter of claim 14, wherein information retention device is an in-circuit programmable device.

16. The imaging catheter of claim 15, wherein the in-circuit programmable device is selected from the group consisting of EEPROM, flash memory and NVRAM.

17. The imaging catheter of claim 15, wherein the in-circuit programmable device is an EEPROM.

18. The imaging catheter of claim 11, wherein the catheter is an ultrasound imaging catheter, the functional component is a transducer and the catheter parameters acquired during manufacturing are selected from the group consisting of transducer gain, transducer center frequency, transducer band width, transducer beam pattern, transducer transfer function, transducer impulse response, sheath artifact amplitude and optical transparency of sheaths.

19. The imaging catheter of claim 10, wherein the information acquired during catheter use is selected from the group consisting of failure mechanisms during use, hospital identification, patient identification and catheter performance deviations from standard and scanned images.

20. The imaging catheter of claim 10, wherein the information acquired during catheter use is the time and duration of use of the catheter.

21. An imaging system comprising: an imaging catheter, having a catheter body, a functional imaging component and an information retention device for storing information and transmitting the information when prompted to an external reader; and an imaging apparatus operably connected to the functional imaging component and to the information retention device, the apparatus having a reader capable of reading the stored information in the information retention device.

22. The imaging system of claim 21, wherein the stored information is catheter parameter information acquired during manufacturing.

23. The imaging system of claim 21, wherein the imaging apparatus further comprises a signal processing unit and an image producing device.

24. The imaging system of claim 22, wherein the imaging system stores a set of ideal parameters and compares those parameters to the catheter parameters that it reads from the information retention device.

25. The imaging system of claim 22, wherein the information retention device stores a set of ideal parameters and compares those parameters to the catheter parameters acquired during manufacturing.

26. The imaging system of claim 21, wherein the system is an ultrasound imaging system and the functional imaging component is a transducer, the system further comprising a patient isolation device to isolate a patient from the system electronics.

27. The imaging system of claim 26, further comprising a motor drive unit operably coupled to the catheter and to the imaging apparatus, the motor drive unit having a communication device operably connected to the information retention device of the catheter and to the imaging apparatus.

28. The imaging system of claim 27, wherein the operative coupling between the catheter information retention device and the motor drive unit communication device is a direct contact, and the patient isolation device is an isolation transformer operably coupled to the catheter and to the imaging apparatus.

29. The imaging system of claim 27, wherein the operative coupling between the catheter information retention device and the motor drive unit communication device is a wireless RF connection and the patient isolation device is the wireless RF connection.

30. The imaging system of claim 29, wherein the communication device and the information retention device each further comprise a radio frequency transmitter/receiver coupled to each device.

31. The imaging system of claim 21 , further comprising a display unit.

32. The imaging system of claim 31 , wherein the display unit further comprises a video processor and a monitor.

33. The imaging system of claim 22, wherein the system is an ultrasound imaging system, the functional imaging component is a transducer and the stored information is selected from the group consisting of transducer gain, transducer center frequency, transducer beam pattern, transducer transfer function, transducer band width, transducer impulse response, sheath artifact amplitude and optical transparency of sheaths.

34. The imaging system of claim 21, wherein the information retention device is a readable rewritable nonvolatile programmable information retention device.

35. The imaging system of claim 34, wherein the information retention device is a readable rewritable nonvolatile programmable electronic information retention device.

36. The imaging system of claim 35, wherein the information retention device is an in-circuit programmable device.

37. The imaging system of claim 36, wherein the in-circuit programmable device is selected from the group consisting of EEPROM, NVRAM and flash memory.

38. The imaging system of claim 34, wherein the stored information is information acquired during catheter use.

39. The imaging system of claim 38, wherein the imaging apparatus has write capability and the information is written to the information retention device by the imaging apparatus.

40. The imaging system of claim 39, wherein the information is selected from the group consisting of failure mechanisms during use, hospital identification, patient identification, catheter performance deviations from standard and scanned images.

41. The imaging system of claim 39, wherein the information is time and duration of use of the catheter.

42. The imaging system of claim 39, wherein the imaging apparatus has a user interface and the information written to the information retention device is information entered by the user.

43. The imaging system of claim 42, wherein the information is selected from the group consisting of hospital identification and patient identification.

44. The imaging system of claim 34, wherein the catheter is operably connectable to a catheter diagnostic apparatus having a reader capable of reading the stored information in the information retention device.

45. A method for producing an image with imaging system comprising a catheter having a functional imaging component and an information retention device, and an imaging apparatus operably connected to the functional imaging component and to the information retention device, the system having a set of ideal parameters stored therein, the method comprising the steps of: writing and storing catheter parameter information in the information retention device; reading the catheter parameter information by the imaging apparatus; comparing the catheter parameter information to the ideal set of stored parameters; creating a set of operating instructions to compensate for deviations in catheter parameters from the ideal set of parameters; adjusting the imaging apparatus based on the operating instructions; scanning an anatomical area having a feature with the functional imaging component of the catheter to detect the feature; sending the feature information to the imaging apparatus; and producing an image with the imaging apparatus.

46. The method of claim 45, wherein the step of writing and storing the catheter parameter information in the information retention device occurs during catheter manufacturing.

47. The method of claim 45, wherein the ideal set of parameters is stored in the imaging apparatus.

48. The method of claim 45, wherein the ideal set of parameters is stored in the information retention device.

49. The method of claim 46, further comprising the step of storing the ideal set of parameters in the information retention during catheter manufacturing.

50. The method of claim 45, further comprising the step of writing and storing information acquired during catheter use in the information retention device.

51. The method of claim 50, wherein the step of writing is performed by the imaging apparatus.

52. The method of claim 51 , wherein the imaging apparatus has a user interface and wherein prior to the step of writing information acquired during use to the information retention device, the method further comprises the step of entering information into the imaging apparatus by the user.

53. A method for diagnosing catheter failure mechanisms in a catheter having a functional component and a readable rewritable programmable information retention device, comprising the steps of: using the functional component of the catheter on an anatomical area of a patient; storing information acquired during catheter use in the information retention device; and reading the stored information to diagnose catheter failure mechanisms.

54. The method of claim 53, further comprising the step of operably connecting the catheter to a control apparatus and wherein the step of reading is performed by the control apparatus.

55. The method of claim 53, further comprising the step of operably connecting the catheter to a diagnostic apparatus and wherein the step of reading is performed by the catheter diagnostic apparatus.

56. The method of claim 53, wherein the information retention device is nonvolatile.

57. The method of claim 55, wherein the information retention device is nonvolatile and the method further comprises the steps of: first, operably connecting the catheter to a control apparatus; disconnecting the catheter from the control apparatus after the step of storing; and operably connecting the catheter to the diagnostic apparatus after the step of disconnecting the control apparatus.

58. The method of claim 53, wherein the stored catheter use information is selected from the group consisting of time and duration of use of the catheter, failure mechanisms occurring during use, hospital identification, patient identification and catheter performance deviations from standard.

59. The method of claim 53, wherein the catheter is an imaging catheter, the functional component is a functional imaging component and the step of using the functional component is imaging.

60. The method of claim 59, wherein the stored catheter use information is a scanned image.

61. A method for standardizing the output of a medical device comprising a medical device having an information retention device and a functional component having an output, and a control apparatus operably connected to the functional component and to the information retention device, the control apparatus having a set of ideal medical device parameters stored therein, the method comprising the steps of: writing and storing medical device parameter information acquired during medical device manufacturing in the information retention device; reading the medical device parameter information by the control apparatus; comparing the medical device parameter information to the ideal set of parameters stored in the control apparatus; creating a set of operating instructions to compensate for deviations in medical device parameters from the ideal set of parameters; adjusting the control apparatus based on the operating instructions; and standardizing the output of functional component of the medical device with the control apparatus.

62. The method of claim 61, wherein the catheter is an imaging catheter, the functional component is a functional imaging component and the control apparatus is an imaging apparatus.

63. The method of claim 61, further comprising the step of using the standardized functional component of the medical device on an anatomical area of a patient.