Patent Publication Number: US-11660067-B2

Title: Image guided catheters and methods of use

Description:
CROSS-REFERENCES 
     This application is a continuation of U.S. patent application Ser. No. 16/247,062, filed Jan. 14, 2019, which is a continuation of U.S. patent application Ser. No. 15/845,756, filed Dec. 18, 2017, which is a continuation-in-part of U.S. patent application Ser. No. 14/865,151, filed Sep. 25, 2015, (now U.S. Pat. No. 9,855,021), which is a continuation-in-part of U.S. patent application Ser. No. 13/847,902, filed Mar. 20, 2013 (now U.S. Pat. No. 9,149,257), and a continuation-in-part of U.S. patent application Ser. No. 13/973,476, filed Aug. 22, 2013; U.S. patent application Ser. No. 13/847,902 is a continuation of U.S. patent application Ser. No. 11/871,282, filed Oct. 12, 2007 (now U.S. Pat. No. 8,403,859) and a continuation-in-part of U.S. patent application Ser. No. 11/782,991 filed Jul. 25, 2007 (now U.S. Pat. No. 8,403,858), both of which claim the benefit of the right of priority to U.S. provisional patent application Ser. No. 60/851,451 filed Oct. 12, 2006; U.S. patent application Ser. No. 13/973,476 claims the benefit of the right of priority to U.S. provisional patent application Ser. No. 61/692,443, filed Aug. 23, 2012; and this application claims the benefit of the right of priority to U.S. provisional patent application Ser. No. 62/526,170, filed Jun. 28, 2017; to U.S. provisional patent application Ser. No. 62/527,865, filed Jun. 30, 2017; to U.S. provisional patent application Ser. No. 62/527,905, filed Jun. 30, 2017; and to U.S. provisional patent application Ser. No. 62/590,464, filed Nov. 24, 2017, the disclosures of all priority applications being hereby incorporated by reference into the present application in their entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments of the illustrated and disclosed aspects and features relate to minimally invasive interventional medical devices having removable and/or reusable components of an ultrasound imaging system and associated channel for introduction of a removeable needle and tools for performing the minimally invasive procedures, and, more particularly, to an ultrasound image guided catheter and methods of use, the catheter elongated housing having a dome-shaped, flat or tapered ultrasound transducer assembly tip at a distal (patient) end, a removable and reusable ultrasound transducer assembly component and a removable and replaceable needle, sheath or tool assembly component. The transducer sensor assembly slidably enters a probe and needle guide housing body and is clasped into a locked position. The ultrasound transducer assembly comprises, for example, a linear phased array at a center frequency of approximately fifteen megahertz (range on ten to forty megahertz) and a pitch between elements of approximately one wavelength (or lambda) (range between 0.85 and 1.15λ or wavelength of center frequency. A conventional pitch of one half lambda or a pitch in the range of 0.5 and 0.6λ or wavelength of the center frequency may be used. The ultrasound transducer assembly is preferably replaceable and reusable with optical coherence tomography or with other assemblies with ultrasound transducers having higher or lower center frequency ranges. The needle or tool assembly may be inserted vertically into a parallel channel of a needle guide, the needle/tool assembly being replaceable with instruments/tools for use at a target site for a medical procedure. The plane of the ultrasound image is mechanically aligned with the needle guide delivery port to ensure that the needle/syringe/tool is visible in the image without the physician needing to make any adjustments to either the imaging array or sheath orientation. In one embodiment, the tool/instrument channel or channels and imaging channel or channels are mounted side-by-side (the needle guide preferably located on top). A patient body region of interest may be visible by the ultrasound transducer assembly from external skin tissue, via a body orifice or subcutaneously. In an embodiment, the needle/tool guide may be mounted above the image guided catheter. Moreover, in other embodiments the needle/tool channel or lumen may extend beyond a transducer window at the distal (patient) end or the transducer window may not extend beyond the needle/tool channel/lumen or lumens. 
     BACKGROUND 
     Ultrasound operates by creating an image from sound in three steps—producing a sound wave, receiving echoes, and interpreting those echoes to create an image. 
     Ultrasound has many uses in medical applications. For example, ultrasound is routinely used during pregnancy to provide images of the fetus in the womb. Generally, a water-based gel is applied to the patient&#39;s skin, and a hand-held probe, called an ultrasound transducer, is placed directly on and moved over the patient. The probe typically contains one or a plurality of piezoelectric elements that vibrates and generates a sound wave when a current is applied. In ultrasound devices, the sound wave is typically produced by creating short, strong vibrational pulses using the piezoelectric transducer element. The sound wave is reflected (echoes) from tissues and structures and returns an echo, which vibrates the transducer elements and turns the vibration into electrical pulses. The electrical pulses are then sent to a processor and then to an ultrasound scanner having a display where they are transformed into a viewable analog or digital image on the display. Ultrasound contrast agents (which may be introduced into the blood) are known for enhancing visibility of blood vessels so that smooth needles, sheaths or tools may avoid inadvertent puncture of a vessel. Surrounding human tissue of blood vessels of interest in a particular medical procedure or blood flow may be seen in an ultrasound image. Also, methods for improving the surface echogenicity of tools are known which permit, for example, improved reflection of sound waves back to the ultrasound transducer assembly. 
     While general-purpose ultrasound machines may be used for most imaging purposes, certain procedures require specialized apparatus. For example, in a pelvic ultrasound, organs of the pelvic region can be imaged using either external or internal ultrasound devices used together or in combination with ultrasound image guided catheters of the present invention (implanted or inserted, for example, via the rectal opening, the mouth, a vein or other useable openings to a human body). In contrast, echocardiography, which is used in cardiac procedures, can require specialized machines to take into account the dynamic nature of the heart. 
     Ultrasound has advantages over other imaging methods such as magnetic resonance imaging (MRI) and computed tomography (CT) or optical coherence tomography (OCT), but these, along with known X-ray imaging can be used together to gather displayed images of a patient&#39;s region of interest. Ultrasound produces a sequence of images in real time and so, for example, a mother may see the ultrasound image of her baby and see the baby&#39;s heartbeat. Also, ultrasound is relatively inexpensive compared to techniques such as MRI and CT. Ultrasound also is capable of imaging muscle and soft tissue very well, can delineate interfaces between solid and fluid filled spaces (for example, for cardiocentesis procedures with a pericardial sac), and may show the structure of organs and their internal components (such as a heart valve). Ultrasound renders live images in real time in sequence and can be used, for example, to view blood vessels in relation to the operation of organs in real time (with or without contrast). Ultrasound has no known long-term side effects and generally causes little to no discomfort to a patient. Further, ultrasound equipment is widely available, flexible and portable. 
     However, ultrasound does have some drawbacks. When used on obese patients, image quality is compromised as the overlying adipose tissue scatters the sound and the sound waves are required to travel greater depths, resulting in signal weakening (attenuation) on transmission and reflection back to the ultrasound transducer (especially a surface-mounted ultrasound system). Even in non-obese patients, depth penetration is limited, thereby making it difficult to obtain images of structures located deep within the body. Further, ultrasound has trouble penetrating bone and, thus, for example, ultrasound imaging of the brain within skull bone is limited from external to animal bone. Ultrasound also does not perform well when there is gas present (as in the gastrointestinal tract and lungs). Still further, a highly skilled and experienced ultrasound operator is necessary to obtain quality images. These drawbacks do not, however, limit the usefulness of ultrasound as a medical diagnostic and treatment tool. 
     The use of ultrasonic apparatus for imaging areas of the human body, either alone or in combination with other instruments, is known, for example, for guiding therapeutic instruments through a catheter to a field of view within a human body. For example, ultrasound devices have been combined with catheters for insertion into a body, usually through a vein or artery, to reach a part of the human body for examination or treatment. Such devices are commonly known in the art as “imaging catheters.” 
     For example, U.S. Pat. No. 5,704,361 to Seward et al. discloses a volumetric image ultrasound transducer underfluid catheter system. For example, FIGS. 2-9 and 11-12 of Seward et al. and their attendant description suggest specific methods of intervention for imaging purposes in the vicinity of a human heart. To reach such an area of interest within a human body, an ultrasound imaging and hemodynamic catheter may be advanced via the superior vena cava to a tricuspid valve annulus. A distal end of a cylindrical body includes a guide wire access port and a guide wire provides a means of assuring that the catheter reaches a target for imaging. A surgical tool may be fed through the catheter to the area imaged. 
     U.S. Pat. No. 6,572,551 to Smith et al. provides another example of an imaging catheter. Tools such as a suction device, guide wire, or an ablation electrode, may be incorporated in an exemplary catheter according to Smith et al. 
     U.S. Pat. No. 5,967,984 to Chu et al. describes an ultrasound imaging catheter with a cutting element which may be an electrode wire or a laser fiber. FIGS. 1 and 2 of Chu et al. also describe a balloon 14 and a means to inflate the balloon. The balloon, for example, may be utilized to dilate a vessel having strictures imaged via the imaging catheter. 
     Other imaging catheters are known. For example, U.S. Pat. No. 6,162,179 to Moore teaches bending (using a pull wire) an acoustic window into a known and repeatable arc for improved three-dimensional imaging. U.S. Pat. No. 6,306,097 to Park et al. discloses an intravascular ultrasound imaging catheter whereby a first lumen provides access for an ultrasound imaging catheter and a second lumen provides a working port for a tool. U.S. Pat. No. 5,505,088 to Chandraratna et al. teaches using a 200 MHz transducer in an ultrasonic microscope combined with a catheter as a delivery means for the microscope to provide imaging of myocardial tissue. According to Chandraratna et al., lower frequency ultrasound transducers can provide deeper penetration in the tissue but do not provide the image quality provided by higher frequencies. 
     Optical coherence tomography (OCT) operates in a similar manner to ultrasound in producing an image having high resolution but the transmitted light signal reaches only so far into human tissue. White light diodes covering the visible spectrum may be used to transmit light through, for example, a transparent window to the human tissue, and the echo is received and passed to a display which may create a three-dimensional image. Near infrared and other radio frequencies, visible and invisible, may be applied to create an image of human tissue at, for example, a site of a medical procedure. 
     Needle guides are known for probes and catheters. Typically, a needle guide may be located at the top of the probe or catheter and provide a channel having a diameter for a specific needle size. The needle may be inserted subcutaneously with or without imaging by sliding the needle from the surgeon end through the needle channel. Also, the needle guide is in one piece and incapable of being opened to release the needle from the probe or catheter. The needle is removed by pulling the needle through the needle channel toward the surgeon end, and the needle may capture debris or fluid such as blood at the needle channel tip as the needle is pulled out of the needle channel. 
     All the above-cited references are incorporated by reference as to any description which may be deemed essential to an understanding of illustrated and discussed aspects and embodiments of devices and methods herein and as summarized below. 
     SUMMARY OF THE EMBODIMENTS 
     This summary is intended to introduce, in simplified form, a selection of concepts that are further described in the Detailed Description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     In an image-guided catheter such as represented by U.S. Pat. No. 9,149,257 entitled “Image Guided Catheters and Methods of Use” issued Oct. 6, 2015 (the &#39;257 patent) by the same inventor, per  FIG.  3 A , an ultrasound beam generated by a transducer element  210  of an ultrasound imaging channel  214  provides a cone-shaped imaging zone  301  which can display a needle  208  directed parallel to the ultrasound beam and located within a sheath or lumen or plurality of lumens. (The &#39;257 patent should be deemed to be incorporated by reference as to its entire contents). One the other hand, the needle  208 , (sheath or tool) being parallel to the cone-shaped ultrasonic beam, may be difficult to see in the imaging zone  301  because the needle, sheath or lumen is very thin in diameter, may comprise a smooth surface, and may extend in the same direction as the ultrasound beam is projected (parallel to the sonic beam) from the thin, minimally invasive image-guided catheter so that the sonic beam will tend to follow the angles of impingement and reflection and are intended to project from the needle, sheath or tool in a direction deeper into, for example, a human body in which the image guided catheter of  FIG.  3 A  is inserted. Also, it is desirable to visualize the needle, sheath or tool itself to determine the direction of its movement within the human body from the point of entry of the human body to an area of interest such as the human heart, the liver or other organ of interest. In one embodiment, the needle or sheath may be hollow (in another, solid) and may be removed once the catheter is located at a site of interest and replaced in real time with a tool. In another embodiment, the tool may be used simultaneously (in its own lumen) with the needle or sheath to bend or guide the needle or sheath to the region of interest from a patient&#39;s skin surface. 
     The following additional U.S. patents and published applications of Dr. Theodore Abraham should be deemed to be incorporated by reference as to their entire subject matter and refer to similar image guided catheters, implanted ultrasound devices, wired or wireless ultrasound devices and the like which may receive signals from echogenic needles, sheaths or tools and surrounding tissue or blood: U.S. Pat. No. 8,038,622 issued Oct. 18, 2011; U.S. Pat. Nos. 8,147,413 and 8,147,414, issued Apr. 13, 2012; U.S. Pat. Nos. 8,403,858 and 8,403,859 issued Mar. 26, 2013, and U. S. 2016/008,1658 published Mar. 24, 2016. 
     A device in accordance with one or more aspects described herein may include ultrasound imaging using a conventional piezoelectric linear or phased array transducer or a more recently developed photo-acoustic transducer (light transmit, sound receive) providing high resolution imaging or optical imaging through the use of fiber optics, i.e. using optical coherence imaging, through an additional channel or lumen than a single ultrasound channel and a single needle/instrument channel, or a combination of these, to provide a wide range of imaging capabilities coupled with one or more diagnostic, therapeutic, or interventional capabilities. In one or more embodiments, according to aspects herein, an interventional ultrasound device preferably may include an expendable housing (useful for one minimally invasive medical procedure) while the ultrasound assembly may be reusable. An optional handle for the use of a surgeon may help the surgeon guide the progress of the device as its distal end progresses into a human body subcutaneously or into a body orifice (as necessary). The image guided catheter device may have a proximal end (the surgeon end) and a distal end, a first lumen, also referred to as an imaging lumen or channel, for holding a replaceable imaging ultrasound transducer assembly of varying center frequency (for example between ten and forty megahertz) and a second lumen which may extend to a distal end or short of the distal end of the expendable housing, also referred to as a needle/instrument lumen, for, for example, a needle guide and for replacing a removable needle or sheath with another interventional device such as a cutting and grasping instrument, sheath or syringe (referred to generally herein as a tool). The imaging transducer assembly may be adapted to removably fit into the imaging lumen at the distal (patient) end of the housing. The transducer assembly may be removed, reused, and/or replaced with imaging transducer assemblies having ultrasound transducers of higher or lower frequency ranges or OCT assemblies and adapted to be used for different purposes in real time, for example, during a medical procedure or comprise additional lumen, for example, for optical coherence tomography imaging or with other ultrasound devices which may be surface-mounted or implanted. 
     Illustrative aspects described herein include a minimally invasive interventional medical device that can provide ultrasound imaging coupled together with one or more interventional capabilities. The ultrasound frequencies present in a sound wave output by such a device can range between twenty kilohertz and several hundred megahertz or ultrasound frequencies in the gigahertz range. Frequencies in the lower range, for example, below one megahertz, and particularly in the 100-200 kilohertz range, can be used, for example, to provide heat therapy or to treat conditions such as blood clots and provide low resolution, long range imaging. Frequencies above one megahertz can be used to provide higher resolution imaging at shorter range. For example, ultrasound frequencies in the 25 to 30 megahertz range can be used to image organs such as the eye or can be used to provide imaging of small animals. Higher frequencies, for example, ultrasound frequencies in the one hundred to several hundred megahertz range, can be used to provide even higher-resolution imaging, sometimes known as high-frequency ultrasound microscopy, at a target site within a body undergoing a medical procedure. A feature of the imaging channel of an embodiment of the present invention is that the ultrasound transducer may be replaceable during a medical procedure to provide imaging for any of these purposes during the procedure via replacement of a replaceable and reusable ultrasound transducer and cabling module, for example, with one of higher center frequency and greater resolution including optical coherence tomography imaging or the use of a plurality of optical fibers. Center frequencies for ultrasound imaging via a linear phased array may vary from ten to forty megahertz and have a sufficiently small diameter for subcutaneous or body orifice use (ear canal, nasal cavity, throat or rectum). In embodiments not shown, more than one imaging lumen/channel may be used at a time during a medical procedure if provided in an embodiment of an image guided catheter. 
     An embodiment of a device in accordance with one or more aspects and features described herein can include a reusable, removable ultrasonic imaging device assembly or module having one or more forward-directed ultrasound transducers, for example, comprising a linear phased array or comprise optical fibers or optical coherence tomography that can be inserted into a distal (patient) end of an expendable catheter housing by way of a lengthwise slot in the proximal end of the housing so as to provide access to the distal end (lumen) of the housing from which, when the ultrasonic or other imaging device assembly is moved forward into the distal end and operated, a direct forward view forming an imaging zone of the tissue being accessed comprising a pie-shaped cross section may be obtained from the ultrasonic or other imaging device assembly and displayed on a display. The imaging zone of the ultrasound transducer may be seen through a dome or window (which may be transparent) of a probe housing assembly having an openable needle guide. An introducer needle may be used during introduction of the device subcutaneously or the probe end be simply used external to the human body or in an orifice of the human body followed by its replacement with an interventional device or instrument introduced via a needle guide, for example, to cut and remove unwanted tissue, a biopsy needle to gather a tissue sample, a syringe to remove unwanted liquid or a sheath to permit a repair or replacement of a heart valve. 
     An embodiment of a device in accordance with one or more aspects and features described herein may comprise a minimally invasive image guided catheter device having a removable, replaceable introducer needle, sheath or instrument (tool) assembly in the needle/instrument lumen and then the one or more replaceable forward-directed ultrasound transducer or optical assemblies that can be inserted and moved forward into the imaging lumen of the single expendable housing via the lengthwise slot at the proximate end so that the introducer needle, sheath or instrument and the imaging catheter (expendable) housing along with the replaceable transducer assembly can be introduced into a body substantially simultaneously via one or more proximate channels. The introducer needle, sheath (or instruments replacing the needle or sheath), the distal tip of the housing and the path taken by the needle or sheath can be viewed within the imaging zone of the replaceable transducer assembly as the entire assembly comprising transducer assembly, housing and instrument/syringe/needle/sheath/tool assembly components may travel through an animal/human body subcutaneously to a target site for a medical procedure or be simply used at skin surface or inserted via a body orifice. A solid or hollow needle, syringe, sheath or other tool may be replaced in the needle channel with medical instruments or carriers of replacement body parts such as heart valves when the operating site via the sheath is reached. 
     An alternative embodiment of a device (shown in priority patent applications and issued patents and published applications of the inventor introduced above) in accordance with aspects described herein can have one or more ultrasonic transducers located along one or more sides of the image guided transducer assembly and housing to obtain peripheral views of the body tissue under medical procedure. The replaceable imaging transducer assembly and removable introducer needle or sheath assembly may comprise a forward-directed ultrasound transducer imaging assembly operating within, for example, a first and second, sonic or optical predetermined range of ultrasound/optical frequencies to enter the human body, then guide the entire image guided catheter to the target site of a medical procedure and provide high resolution (high frequency or optical coherence or both) imaging at the target site of a medical procedure. A tool such as a clasper or microelectromechanical motor system may be introduced to help guide the sheath or needle upwards or downwards to reach the site of interest or may replace the needle or sheath when located at the site of interest, for example, to repair or replace a heart valve. 
     The ultrasound features of the device can serve to guide and facilitate surgical procedures performed with the image guided catheter device. For example, a medical professional such as a surgeon can receive direct high-resolution vision of a targeted area in real time. The lumen for example, for receiving a syringe or surgical instrument and introducer needle assembly may have inserted and locked into place therein, a hollow syringe needle for withdrawing unwanted fluids or tissue specimens or a tapered solid needle for, for example, skin penetration and internal body wall puncture may be used when needed via the tool replacement feature and multiple usage of a single instrument lumen or channel or used together with a tool in a second parallel lumen and visioned by ultrasound or OCT or other imaging channel. 
     A wide variety of other interventional elements also can be incorporated into such a device. Examples of replacements for a syringe/needle assembly in the needle or sheath lumen may include a syringe for removing fluids, an instrument having a biopsy needle for extracting tissue specimens, an instrument including a biopsy blade, an instrument carrying a micro-motive electronic manipulator (MEMS) device, an instrument comprising a clasper for cutting and clasping tissue for removal and other instruments as described in priority patent applications and issued patents. A syringe needle may be hollow or solid and may be used as an introducer needle or larger diameter sheath for another device and for delivering medication or for removing unwanted fluid (for example, unwanted fluid in the pericardial sac or space). 
     For example, in some embodiments of a device in accordance with one or more aspects and features described herein, an ultrasound imaging transducer assembly can be combined with an interventional catheter having an introducer needle so that the catheter distal end can be inserted under ultrasound imaging guidance directly into the target site (the proximal end being held by a handle and used by medical personnel to grasp the assembled image guided catheter device with one hand while replaceable needles, tools, transducers of different frequencies, optical fibers and the like are inserted in the two or more channels to the distal end). For example, the image guided catheter can be inserted directly through the chest wall, guided to a heart and then into the heart using the introducer needle without having to make entry through another means such as through a blood vessel in a human leg or other vein or by using a guide wire as is taught with prior art devices. If necessary, an ultrasound transducer assembly having a longer range and lower resolution may be replaced in real time during the movement of the image guided catheter assembly with a higher resolution and shortrange transducer assembly as the target site is reached or used with a high resolution short range optical coherence tomography or plurality of optical fibers or other known vision device. Once at the target location for a medical procedure, the removable needle or sheath may be removed and replaced with another instrument such as a biopsy needle, MEMS device, tissue clasper or biopsy blade among other instruments (tools). 
     In another embodiment in accordance with one or more aspects herein, a medical device is provided that can comprise one or more ultrasound transducers coupled or associated with a syringe element for delivery of medication or withdrawal of unwanted fluids at a treatment site. An exemplary syringe that may be used to replace an introducer needle assembly once the device is at the target site is a needle assembly such as is described in U.S. Pat. No. 6,592,559 to Pakter et al., which may deliver multiple needles to multiple sites within the body at the target site. 
     A MEMS device may be deployed via the distal end to help guide upwards or downwards the needle, syringe or sheath as the catheter is surgically moved towards a site of interest. Furthermore, a tool may replace a solid or hollow needle, syringe or sheath once a site of interest is reached using the needle guide. 
     According to other aspects, at the proximal end of such a device, an anchoring portion may be provided for anchoring the device to a human body once the device is image-guided to the diagnosis or treatment site or alternatively the device may be manipulated by a handle grasped in one hand by the surgeon. The proximal end may also include locking mechanisms for securing the removable, replaceable imaging transducer assembly and/or a replaceable syringe with another medical device or instrument of the expendable housing component while the image catheter device is in use during a medical procedure. 
     According to aspects herein, the housing of such a device may be formed from one or more of a variety of materials such as silicone, Teflon, polyurethane, PVC, TPX, and/or elastomeric hydrogel. According to some aspects, the housing may be cylindrical in shape and may include, for example, a catheter or vascular sheath. As will be shown herein, the needle/instrument channel and an ultrasound transducer channel may be mounted side by side one another or one on top of the other. The expendable housing may be tapered at the distal (patient) end or have a dome or a window that may be flat and transparent for the ultrasound transducer, optical coherence tomography or plurality of optical fibers, once inserted in the imaging transducer channel/lumen or in its own lumen. According to some aspects, the ultrasonic probe housing may have a lengthwise slot opening at the proximal cross-sectional side allowing its user to freely remove and replace the replaceable imaging transducer assembly while the image guided catheter device is being used during a minimally invasive medical procedure. 
     According to aspects herein, the imaging transducer assembly may comprise a forward viewing linear phased array probe with a variable field of view depending on the specific array and choice of center frequency and frequency range. The imaging transducer assembly may comprise a plurality of ultrasound transducers at the distal end with variable frequency, variable cross-sectional diameter, and a variable number of transducer elements located in a steel or rigid plastic cylinder with a varying outer diameter, for example, wherein the expendable housing may have two or three different outer diameters during its length from a large outer diameter surgeon grasp and optional handle at the proximal end of the expendable housing to a very small outer diameter at the distal end, typically referred to herein as the barrel having a small diameter for just the imaging and instrument channels/lumens. 
     According to aspects herein, the syringe/needle assembly/instrument lumen may fit a removable variable gauge solid introducer needle, a hollow syringe needle, a sheath or other interventional instruments as discussed above once the operating target site is reached. The needle, sheath or tool may be echogenic and comprise a variegated surface by sanding, engraving, etching or wrapping wire of non-allergic material round the catheter needle or sheath or tool. 
     These and other aspects of embodiments of an image guided catheter assembly will be discussed with reference to the drawings, a brief description of which follows. 
     In the brief description of the drawings, for drawings  FIG.  1 A  through  FIG.  12 I , similar reference numerals are used to denote similar elements and the first numeral of a reference numeral such a 1XX denotes the figure in which the element first appears, in this case,  FIG.  1   . Also, the XX portion of a reference numeral is intended to refer to a similar component in each figure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings are exemplary and are not intended to limit the dimensions of the depicted elements to those shown in the drawings. All dimensions may vary with the particular application of the image guided catheter or probe depicted in the several drawings. 
         FIG.  1 A  through  FIG.  6 B  depict a disposable assembly comprising a needle guide, and a tab which may be moved circularly round the elongate probe housing to close one half of the needle guide onto the other half so that a needle (or syringe or other tool) may be placed vertically into the open needle guide, the needle guide closed about the tool and the tool removed therefrom, for example, vertically, a probe barrel containing an ultrasound transducer section and a disposable sheath section which has a locking tab. A second assembly, not introduced until  FIG.  9 A  is discussed, comprises the ultrasound transducer assembly, a probe housing, a sheath and a cable narrowing section and the exiting cable which connects to a processor and display not shown. The ultrasound transducer assembly provides an imaging plane (referred to in earlier patents as an imaging zone) capturing a region of interest originating from the transducer array. 
         FIG.  1 A  depicts a view of a patient or distal end of an image guided catheter device assembly in accordance with one or more aspects described herein,  FIG.  1 A  showing a replaceable introducer needle/syringe/instrument channel  103  above a transducer sensor tip channel  105 , the needle/tool guide  103  having a tapered distal tip  104 . When a needle protrudes from this distal tip  104 , the needle is visible in an imaging zone (not shown) of the removable, replaceable transducer element or array within the probe distal end  105  replaceable, for example, as higher resolution is needed when the access instrument reaches the operating site. A tab  106  is shown for use by a surgeon to open or close the needle guide  103  for insertion of a needle/syringe or other tool. Body or sheath  102  may comprise additional lumen or channels and may comprise a sensor channel or lumen  105  for additional needles/tools (not shown) and may contain leads to the transducer array behind tip  105  that form a cable to a processor and display (not shown). A locking tab  101  is provided for permitting insertion of a probe, transducer and cable assembly which may comprise a linear phased array transducer assembly having a collection of leads to each piezoelectric element which form a cable (not shown) but exiting at the rear of sensor channel  102  to a section first shown in  FIG.  9 A . Button tabs  107  and  108 , when needle guide  103  is in an open position, serve to push up on a needle, syringe or tool in the needle guide  103  so as to release it (for example, if the needle comes in contact with a sticky substance such as coagulated blood). Tab  106  will be seen to be used to lock two halves of needle guide  103  together. 
         FIG.  1 B  depicts a top view of a needle guide  103  of  FIG.  1 A  to show how guides  121  and  122  guide a needle or tool into a needle channel and can rest on needle buttons  107 A and  108 A of one side of the needle guide  103  and also rest on needle buttons  108 A and  108 B of the other side of the needle guide. 
         FIG.  1 C  depicts an open front view of the needle guide  103 . A needle (syringe or tool) may be moved out of the guide sides shown due to opening guides  121  and  122 . Button tabs  107 A and  107 B along with button tabs  108 A and  108 B help extricate the needle from the needle guide  103  from above. 
         FIGS.  2 A and  2 B  depict different cross-sectional views of the patient or distal end of the embodiment of  FIG.  1    where tab  106  for closing the needle channel is now referenced as tab  206  for opening the needle channel  203  of an imaging device in accordance with one or more aspects described herein. When tab  206  is manipulated in a clockwise direction round the elongated housing&#39;s cylindrical body, the needle channel is closed around a needle/syringe/tool (not shown).  FIG.  2 B  shows additional button tabs  209 ,  210  which may be used or not used in a given embodiment to further serve to support a needle/syringe/tool in needle channel tabs ( FIGS.  1 B and  1 C ). Needle channel tip  204  is tapered and may receive and permit a tapered tip hollow needle (possibly of a syringe) to exit the needle guide at tip  204 . Sensor channel tip  205  may indicate the location of an ultrasound sensor not seen which may be directed forward and provide forward-imaging of a needle/syringe/tool in the needle channel  203 . In either figure, a rear tab  101 ,  201  may lock a sensor and cable section assembly in place within the body  202  comprising a sensor channel (transducer assembly and cabling). Needle  1010  and sensor and cable assembly  1006  are first seen in  FIG.  10    locked in place by locking tab  1001 . 
         FIG.  3 A  provides an enlarged front-end view of the tab  106  now seen as tab  306 A which may move between positions  309  and  310  to open or close the needle channel. In  FIG.  3 A , the needle channel tip  304 A is shown closed. 
       In  FIG.  3 B , the needle channel tip  304 B is shown open. Similarly, a first part of the needle channel  321 A is shown closed in  FIG.  3 A , and the same part of the needle channel  322 B is shown open in  FIG.  3 B . Sensor channel  302  of either  FIGS.  3 A and  3 B  carries the sensor and cable to the sensor channel tip  305 . A second part of the needle channel  322 A or  322 B remain stationary where line  320  represents the line along which the needle channel opens. Section A-A extends from the top of the needle channel through the sensor body  302 . 
         FIGS.  4 A and  4 B  depict details of the opening and closing of a needle channel using tabs  106  where  FIG.  4 A  represents a closed needle channel and  FIG.  4 B  represents and open needle channel, for example, where partial circular sections connected to tab  106  comprise line  420  along which the needle channel opens.  FIG.  4 A  comprises closed needle channel tip  404 A, the first part  421 A of the closed needle channel, the second part  422 A of the closed needle channel, and the sensor channel tip  405  of the ultrasound sensor channel. Referring to  FIG.  4 B , sensor channel tip  405  is in the center. Surrounding this center  405  are open needle channel tip  404 B, open second part  422 B of the needle channel and open first part  421 B of the needle channel. Section C-C is taken just of the probe housing as seen in  FIG.  1 A . 
         FIGS.  5 A and  5 B  depict in rear perspective view a closed needle channel  504 A ( FIG.  5 A ), button tabs  507 ,  508 , and closed needle entry  503 A ( FIG.  5 A ) leading to distal closed tip  504 A ( FIG.  5 A ) of the needle channel sensor channel tip  505  (seen in both  FIGS.  5 A and  5 B ). The sensor body  502  in both figures has a tab  501  for allowing a sensor probe and cable to be placed within the housing per  FIG.  10   . Closing tab  506 A in  FIG.  5 A  shows a close position for the needle guide while closing tab  506 B in  FIG.  5 B  shows an open position for the needle guide as per open needle guide  503 B. Distal tip  504 A is shown closed in  FIG.  5 A  and open tip  504 B is shown in  FIG.  5 B . Circle D shows the difference between closed needle guide  503 A ( FIG.  5 A ) and open needle guide  503 B ( FIG.  5 B ) where opening and closing uses tabs  506 A (closed) and the same tab  506 B in an open position. 
         FIGS.  6 A through  12 I  show an embodiment similar to the previously discussed embodiment whereby a sleeve lock is used to lock two halves of a needle channel of a needle guide together around an inserted tool: for example, a needle, syringe or other tool. 
         FIGS.  6 A and  6 B  depict front perspective views of the line  620  along which the needle channel  603  opens along with a portion of the sensor housing or body  602 . Referring to  FIG.  6 A  needle channel  603 A is in a closed position, the first part of the needle channel  621 A is closed as is the second part (for example, half) of the needle channel  622 A. Referring now to  FIG.  6 B , the needle guide is in an open position  603 B and the first and second parts  621 B and  622 B (for example, halves) of the needle channel are opened. 
       Thus far, we have discussed how a tab  106  may open and close a needle channel. In  FIGS.  7 A through  8 H  and in  FIG.  9 A  an alternative to a tab closure is shown that comprises a sliding groove  724  moved by a surgeon via a circular or partially circular tab or sleeve lock  723  with unnumbered finger grips seen as rounded gripping ridges on the sides of the sleeve lock  723 . 
         FIG.  7 A  shows sensor housing channel  702  and the needle channel  703  in a closed position where the circular tab or sleeve lock  723  and groove  725 A have been slid forward to clasp the two halves of a needle guide  703  together. The groove may have parallel sides shown or have V-shaped clasping sides. The parallel sides  721  and  722  ( FIG.  7 B ) of groove  724  may have a corresponding quarter-circular portion  725 A which gathers the two sides  721 ,  722  of the needle guide together, and the groove  724  holds the needle guide together. A retaining spring tab  712  retains the sleeve lock so as to close the needle channel  703  of the needle guide. 
       In  FIG.  7 B , it may be seen that a matching quarter-circular portion  725 B matches portion  725 A and so, when they meet as the tab  723  is closed, the two sides  721 ,  722  of the needle guide  703  are caused to collapse and be held by together by the groove  724  via sleeve lock  723  as seen in  FIG.  7 A . 
         FIG.  8 A  depicts a top down view of the groove closure of  FIGS.  7 A and  7 B . As already seen, sensor housing  809  has a locking tab  801  for linking with a sensor and cable assembly seen in  FIG.  10   . Needle guide  803  is seen held closed in a groove and is so held in a closed position as long as the groove grips the halves of the needle guide  803  together. Retaining tab  812  holds sleeve lock  823  closed also closing needle channel  803 . 
         FIG.  8 B  provides a side cross-sectional view of the sensor and needle guide assembly shown in top view in  FIG.  8 A . Sensor  802  has a locking tab  801  for linking to an internal transducer and cable assembly per  FIG.  10    as seen in  FIG.  8 A  in top view. Needle guide  803  is shown closed with button tabs  807  and  808 . Retaining tab  813  prevents a sleeve lock  823  from opening any further than its raised edge. 
         FIG.  8 C  depicts an expanded view of the closing groove mechanism (Detail B) for closing the needle guide first and second parts  821  and  822  along line  820  via quarter-circular groove portions  825 A and  825 B so that sleeve lock  823  in a forward position closes the needle guide within the depicted groove  824 . 
         FIG.  8 D  shows a side view similar to the side cross-sectional view of  FIG.  8 B . The sensor channel  802  is seen at the distal end and the tab  801  at the proximal end. The finger grip  823  is shown extended so as to force the needle channel  803  closed with button tabs  807  and  808 . 
         FIG.  8 E  is a front perspective view of the sensor housing of  FIG.  8 D . An ultrasound sensor channel  802  is located below the needle channel indicated by button tabs  807  and  808  and needle guide opening  803 . The needle channel  803  is closed by a sleeve lock  823  and retained in a closed position by retaining tab  812 , the sleeve lock  823  having finger grips as seen and a groove (not visible) which holds the halves of the needle guide  803  together. Also shown are a disposable plastic sheath  809  and locking tab  801  for locking together with a sensor and cable assembly seen in  FIG.  10   . Circle D will be described in  FIG.  8 F . 
         FIG.  8 F  provides an expanded view (Detail D) of the sleeve lock  823  showing needle guide halves  821 ,  822  held together in a groove  824  facilitated by quarter-circular section  825 A. 
         FIG.  8 G  shows a rear perspective view of the needle guide and sensor housing with locking tab  801 , needle guide  803 , button tabs  807 ,  808 , sensor housing  803 , quarter-circular section  825 A of a gripping groove of sleeve lock  823  held in closed position by retaining tab  812  and disposable plastic sheath  809 . Circle C will be described with reference to  FIG.  8 H . 
         FIG.  8 H  provides a rear expanded perspective view of the closure of needle guide  803  (Detail C) having halves  821  and  822  within a groove  824  of sleeve lock  823  having a quarter-circular section  825 A for matching with needle guide quarter-circular section  825  along closure line  820 . 
         FIG.  8 I  provides a cross-section of the disposable plastic sheath portion including sheath  809 , the needle channel distal tip  804  and the sensor channel tip  805  which may comprise a window for an internal ultrasound transducer assembly (not shown). 
         FIGS.  9 A through  9 I  provide views of a combination assembly of the sensor housing and needle guide section with the sensor and cabling section using the groove needle guide locking mechanism or sleeve lock  923  as discussed above. Alignment of the imaging plane  919  (or zone of reflected imaging) with the needle delivery port of the needle guide  903  permits ultrasound visibility of the needle/syringe/tool or other device within the imaging plane when these are introduced subcutaneously into a patient. 
         FIG.  9 A  provides a top view of the combination assembly comprising from left to right sensor channel tip  905  with a needle guide tip directly above but not easily discernable. Sensor channel  902  holds, for example, a probe comprising a linear phased array with each element connected to leads of a cable (not seen) until the cable exits at right as cable  906 A. An imaging plane or zone is seen surrounding the linear phased array within a range around the center frequency. Alignment of the imaging plane with the needle delivery port portion of the sheath permits ultrasound display of an emerging needle/biopsy needle/syringe/other tool of needle guide  903 . Needle guide  903  is shown closed within a groove of circle B. Gripping tab  923  that may slide back is shown closed and retained by retaining tab  912  so that a groove closes needle guide  903 . Next to the right is disposable sheath  909  and a cable joining section  906 B of a probe, probe housing and cable assembly. 
         FIG.  9 B  is a cross-section along line A-A of  FIG.  9 A  so as to see the internal components of the combination assembly. A right-side cross-section of the assembly comprises from right, cable  906 A which merges with cable joining section  906 B and the individual piezoelectric element leads (from each element may be combine to form a cable) may pass through sections  906 B and  906 C (a probe section) to, for example, a linear phased array of elements facing forward at sensor tip  905 . Tab  901  locks needle guide section  902 ,  903 ,  904 ,  907 ,  908 , along with cable section disposable housing  909  to the internal cable and sensor sections  906 A,  906 B and  906 C. 
         FIG.  9 C  is a further exploded top view (Detail B) of the needle guide locking mechanism comprising along closing line  920  a first quarter-circular groove section  925 A and an opposite quarter-circular grove section  925 B of groove  904  of sleeve lock  923  which close around needle guide halves  921  and  922  to close the needle guide  903 . 
         FIG.  9 D  is a complete assembly side view comprising from left to right a sensor tip  905 , a sensor housing  902 , needle guide button tabs  907  and  908  and needle guide  903 . The sleeve lock  923  is seen in a closed position so that needle guide  903  would be closed. Disposable plastic sheath  909  is seen next with tab  901  holding sensor and cable assembly  906 A and  906 B in place, mostly internally within the housings  902  and  909 . 
         FIG.  9 E  provides a front perspective view of the entire assembly. Starting from left is seen the sensor housing tip  905 , the probe housing  902 , needle guide button tabs  907 ,  908 , the needle channel  903  with sleeve lock  923  having quarter-circular section  925 A for locking the needle guide  903  in a groove of sleeve lock  923  in a closed position (Circle D discussed in  FIG.  9 F ) held by retaining tab  912 , disposable plastic sheath section  909  (covering cable) and ultrasound sensor and cable sections  906 B and cable  906 A may be seen. When sleeve lock  923  is moved to the rear opening the needle channel  903  via the sleeve lock  923 , the sleeve lock  923  is retained by a retaining tab on the bottom of sheath  909 . A forward-directed linear phased array would be located just behind sensor tip  905 , and the array provides an imaging plane which may be aligned with the needle guide delivery port portion of the sheath of the needle guide  903  for displaying in real time a position of a needle/syringe/tool emerging from the needle guide and used subcutaneously. An approximately two-dimensional ultrasound imaging plane  919  is shown to be oriented perpendicular to the face of the ultrasound array to the center of the needle port delivery port portion of the sheath; (see also FIG.  9 I). This ensures that during a procedure the needle or other tool emerging from the needle guide  903  at its distal port is automatically visible in the ultrasound image without the physician needing to adjust the relative orientation of a sheath or ultrasound probe. 
         FIG.  9 F  provides a front perspective view of the needle guide locking mechanism in a closed position along line  920  (Detail D). Sleeve lock  923  locks needle guide halves  921  and  922  together in a groove  924  having a quarter-circular section  925 A and a rear groove face  926 A and is retained in closed position by retaining tab  912  ( FIG.  9 E ). 
         FIG.  9 G  provides a rear perspective view of the combination assembly from left to right comprising the sensor housing tip  905 , the probe housing  902 , needle guide button tabs  907 ,  908 , the needle channel  903  with sleeve lock  923  having quarter-circular section  925 A for locking the needle guide  903  (in circle C) in a groove of sleeve lock  923 , disposable plastic sheath section  909  (covering cable) and ultrasound sensor and cable sections  906 B and cable  906 A may be seen along with tab  901  for holding the outer housing together with the probe and cable assembly. A forward-directed linear phased array would be located just behind sensor tip  905  and the array provides an imaging plane  919  which may be aligned with the needle guide delivery port portion of the sheath of the needle guide  903  for displaying in real time a position of a needle/syringe/tool emerging from the needle guide and used subcutaneously. 
         FIG.  9 H  is an exploded view of Detail C where needle guide halves  921 ,  922  of needle guide  903  are held together by a groove  924  of sleeve lock  923 . 
         FIG.  9 I  is very similar to  FIG.  8 I  and shows a cross-section of the disposable plastic sheath portion  909 , the needle channel tip and the sensor channel tip  905 , the needle channel tip being the end portion of the needle guide  903 . The exact orientation of the ultrasound image plane  919  is shown to intersect the center of the imaging array and needle delivery port, thereby ensuring that the needle or other tool being delivered will be visible in a processed ultrasound image (not shown) without the physician having to adjust the relative position of the sheath or ultrasound probe. 
         FIGS.  10 A through  10 I  depict several views of the above-described needle guide embodiment and probe and cable assembly also including an exemplary needle having a handle  1010  and a tip  1011 . The needle  1011  and handle  1010  are shown in the needle channel  1003 . The needle  1010 ,  1011  may be a biopsy needle and be hollow for collecting tissue at a site of interest located by forward-imaging of a transducer array located behind sensor tip  1005 . Retainer tab  1012  retained sleeve lock  1023  in a closed position. 
         FIG.  10 A  shows section A-A seen in  FIG.  10 B .  FIG.  10 A  from left to right includes but is not limited to showing needle tip  1011 , closed needle guide  1003 , sleeve lock  1023 , needle handle  1010 , circle B for explaining the locking mechanism, disposable plastic sheath section  1009 ; letter A where the clasp  1001  would be located on the underside and is not visible, cable narrowing section  1006 B and cable section  1006 A. Needle handle  1010  may comprise a syringe. 
         FIG.  10 B  shows section A-A comprising from left to right a needle tip  1011 , button tabs  1007  and  1008  which assist in lifting needle  1011  (or other tool) vertically out of the needle channel  1003 , sensor tip  1005 , probe  1006 C, piezoelectric element signal leads  1002  (from array elements to form a cable), needle handle  1010 , locking tab  1001  in the vicinity of A of  FIG.  10 A , cable narrowing section  1006 B and cable section  1006 A from which a cable exits a proximal end toward a processor and display (not shown). 
         FIG.  10 C  provides an expanded view of detail B (circle B of  FIG.  10 A ) showing the needle channel halves  1021 ,  1022  in a locked position in groove  1024  having been guided into groove  1024  by quarter-circular edges  1025 A,  1025 B of the distal end of groove  1024 .  FIG.  10 C  also shows needle handle  1010  and a top viewable portion of locking sleeve  1023 . 
         FIG.  10 D  is a side view of a complete assembly including both a probe and cable housing portion  1005 ,  1002 ,  1009 , a locking sleeve  1023  held in a closed position by retaining tab  1012 , a needle  1011  and handle  1010  held in needle channel  1003  by button tabs  1007 ,  1008  and a disposable sheath  1009  having a retaining tab  1001  for securing a cable and probe section  1006 A,  1006 B. Retaining tab  1013  stops sleeve lock  1023  from moving rearwards along sheath  1009 . 
         FIG.  10 E  provides a front perspective view of a complete assembly as seen in  FIG.  10 D  comprising four components, a needle  1011  and needle handle  1010 , the needle residing in a needle channel  1003  of a needle guide, the needle  1011  supported by button tabs  1007  and  1008  of the needle guide portion of a probe and cable housing comprising the needle guide, a distal probe tip window  1005 , a probe housing  1002  and a disposable sheath  1009  having a locking tab  1001  for locking, for example, a probe containing a linear phased transducer array located behind the window  1005 , and element leads to a cable exiting the sheath  1009  via cable narrowing section  1006 B while cable  1006 A leads to a processor and display (not shown) and the sleeve lock  1023  which is slid down sheath  1009  and over retaining tab  1012  to close needle channel  1003  over needle  1011 . Circle D will be discussed with reference to  FIG.  10 F . 
         FIG.  10 F  provides an expanded view of detail D (circle D of  FIG.  10 E ) showing the needle channel halves  1021 ,  1022  in a locked position in groove  1024  having been guided into groove  1024  by quarter-circular edges  1025 A,  1025 B (not visible) of the distal end of groove  1024  joining the two halves  1021 ,  1022  of needle channel  1003 .  FIG.  10 F  also shows needle handle  1010  and a top viewable portion of locking sleeve  1023 . 
         FIG.  10 G  provides a rear perspective view of a complete assembly as seen in  FIG.  10 D  comprising four components, a needle  1011  and needle handle  1010 ; the needle  1011  residing in a needle channel  1003  of a needle guide, the needle  1011  supported by button tabs  1007  and  1008  of the needle guide portion of a probe and cable housing comprising the needle guide, a distal probe tip window  1005 , a probe housing  1002  and a disposable sheath  1009  having a locking tab  1001  for locking, for example, a probe containing a linear phased transducer array (not shown) located behind the window  1005 , and element leads to a cable exiting the sheath  1009  via cable narrowing section  1006 B while cable  1006 A leads to a processor and display (not shown) and the sleeve lock  1023  which is slid down sheath  1009  during assembly and over retaining tab  1012  to close needle channel  1003  over needle  1011 . Circle C will be discussed with reference to  FIG.  10 H . 
         FIG.  10 H  provides an expanded view of detail C (circle C of  FIG.  10 G ) showing the needle channel halves  1021 ,  1022  in a locked, closed position in groove  1024  having been guided into groove  1024  by quarter-circular edges  1025 A,  1025 B (not visible) of the distal end of groove  1024  joining the two halves  1021 ,  1022  of needle channel  1003 .  FIG.  10 H  also shows needle handle  1010  and a top viewable portion of locking sleeve  1023 . 
         FIG.  10 I  is very similar to  FIGS.  8 I and  9 I  but differs in showing needle tip  1011  emerging from needle guide  1003  and shows a cross-section of the disposable sheath portion  1009 , the needle channel tip  1004  and the sensor channel tip  1005  with the end portion of the needle guide  1003 . 
         FIG.  11 A  provides a top view of a complete assembly of an image guided catheter or probe  1100  as seen also in  FIG.  10 E  with sleeve lock  1123  open comprising four components, a needle  1111  and needle handle  1110 , the needle still residing in a needle channel  1103  of a needle guide, the needle  1111  supported by button tabs (not visible) of the needle guide portion of a probe and cable housing comprising the needle guide, a distal probe tip window  1105 , a probe housing  1102  and a disposable sheath  1109  having a locking tab (not visible) for locking, for example, a probe containing a linear phased transducer array located behind the window  1105 , and element leads to a cable exiting the sheath  1109  via cable narrowing section  1106 B while cable  1106 A leads to a processor and display (not shown) and the sleeve lock  1123  which is slid down sheath  1109  and over retaining tab (not visible) to close needle channel  1103  over needle  1111  via groove  1124 . Circle B will be discussed with reference to  FIG.  11 C . Cross-section A-A will be discussed with reference to  FIG.  11 B . 
         FIG.  11 B  provides a cross-section view of a complete assembly along A-A of  FIG.  11 A  and comprises four components, a needle  1111  and needle handle  1110 , the needle  1111  residing in a needle channel  1103  of a needle guide, the needle  1111  supported by button tabs  1107 ,  1108  of the needle guide portion of a probe and cable housing comprising the needle guide located at the top, a distal probe tip window  1105 , a probe housing  1102  and a disposable sheath  1109  having a locking tab  1101  for locking, for example, a probe containing a linear phased transducer array located behind the window  1105  seen as section  1106 C, and element leads (not shown) to a cable section  1106 A exiting the sheath  1109  via cable narrowing section  1106 B while cable  1106 A leads to a processor and display (not shown) and the sleeve lock  1123  which is slid down sheath  1109  and over retaining tab  1113  to close needle channel  1103  over needle  1111  via groove  1124 . The needle channel  1103  is open and sheath  1123  has not been moved toward the distal tip  1105  to close the needle channel  1103 . 
         FIG.  11 C  provides an expanded view of Detail B of  FIG.  11 A  showing the needle channel open and comprises the needle channel halves  1121 ,  1122  in an open, unlocked position outside groove  1124  having been released from groove  1124  and quarter-circular edges  1125 A,  1125 B of the distal end of groove  1124  releasing the two halves  1121 ,  1122  of needle channel  1003  to expose to view needle  1110  with its handle  1111  also visible.  FIG.  11 C  also shows needle handle  1111  and a top viewable portion of locking sleeve  1123 . 
         FIG.  11 D  provides a side view of the complete assembly of four parts with the needle channel  1103  open but the needle  1111  and needle handle  1110  still residing in the needle channel. Locking sheath  1123  has been moved toward the proximal end to be stopped by retaining tab  1113 . From left to right, imaging window  1105  of probe housing  1102  has mounted thereon a needle guide comprising button tabs  1107 ,  1108  supporting needle  1111  in needle channel  1103 . At the end of needle channel  1103  is seen a quarter-circular edge of the channel which mates with quarter-circular edge  1125 A of groove of open sheath  1123  when closed but, when open, locking sheath  1123  rests against retaining tab  1113  and surrounds sheath  1109 . Locking tab  1101  locks in probe and cable assembly comprising a cable narrowing section  1106 B leading to cable  1106 A. 
         FIG.  11 E  is a front perspective view of a complete assembly with the needle channel  1103  open and the needle  1111  and needle handle  1110  are exposed and are supported on button tabs  1107  and  1108  of the needle guide. From left, the probe housing tip or window  1105  is seen on probe housing  1102  while sleeve lock  1123  is shown open on disposable sheath  1109 . Locking tab  1101  locks probe and cable section within comprising visible cable narrowing section  1106 B and cable  1106 A. Circle D will be described with reference to  FIG.  11 F . Needle handle  1110  may comprise a syringe having two cylindrical sections. 
         FIG.  11 F  is an expanded view of detail D of  FIG.  11 E  showing the needle channel halves  1121 ,  1122  open exposing to view needle  1111  and needle handle  1110  and comprises the needle channel halves  1121 ,  1122  in an open, unlocked position outside groove  1124  having been having been released from groove  1124  and quarter-circular edges  1125 A,  1125 B of the distal end of groove  1124  releasing the two halves  1121 ,  1122  of needle channel  1103  to expose to view needle  1111  with its handle  1110  (which may comprise a syringe) also visible.  FIG.  11 C  also shows needle handle  1110  and a top viewable portion of locking sleeve  1123 . 
         FIG.  11 G  is a rear perspective view of the complete assembly with the needle channel  1103  open and the needle  1111  and needle handle  1110  are exposed and are supported on button tabs  1107  and  1108  of the needle guide. From left, the probe housing tip or window  1105  is seen on probe housing  1102  while sleeve lock  1123  is shown open on disposable sheath  1109 . Locking tab  1101  locks probe and cable section within, the section comprising visible cable narrowing section  1106 B and cable  1106 A. Circle C will be described with reference to  FIG.  11 H . Needle handle  1110  may comprise a syringe having two cylindrical sections, one for holding fluid and a pull handle for withdrawn fluid through needle  1111 . 
         FIG.  11 H  is an expanded view of detail C of  FIG.  11 G  showing the needle channel halves  1121 ,  1122  open exposing to view needle  1111  and needle handle  1110  and comprises the needle channel halves  1121 ,  1122  in an open, unlocked position outside groove  1124  having been having been released from groove  1124  and quarter-circular edges  1125 A,  1125 B of the distal end of groove  1124  releasing the two halves  1121 ,  1122  of needle channel  1103  to expose to view needle  1111  with its handle  1110  (which may comprise a syringe) also visible.  FIG.  11 H  also shows needle handle  1110  and a top viewable portion of locking sleeve  1123 . 
         FIG.  11 I  is a top perspective expanded cross-sectional view showing open needle channel  1103  comprising needle channel halves  1121  and  1122  in an open position. Needle  1111  has handle  1110  shown still inside the needle open channel  1103  comprising halves  1121  and  1122 .  FIG.  11 I  further shows cross-section  1109  of disposable sheath  1109  and the probe window or distal probe housing end  1105 . 
         FIGS.  12 A through  12 I  are identical to  FIGS.  11 A through  11 I  but for the movement of needle  1211  (or other tool) and handle  1210  (or syringe portion) vertically out of the needle channel  1203  and will not be described in any detail to avoid redundancy. However,  FIG.  12 I  will be briefly explained as it shows the needle  1111  removed from the channel vertically. 
         FIG.  12 I  shows needle handle  1210  and needle  1211  removed vertically and outside the open needle channel comprising open needle channel halves  1221  and  1222 . Probe distal end  1205  is seen as is the sheath section  1209  in cross-section. 
         FIGS.  13  through  17 B  provide an overview of the insertable probe, cable and linear phased array transducer assembly  1006 A,  1006 B,  1106 C, that is locked by locking tab  101 ,  201 ,  501 ,  801 ,  901 ,  1001 , for example, inside disposable sheath  102 ,  202 , 502 ,  909 ,  1009 , for example. 
         FIG.  13    present provides a side view at its center of a plurality ultrasonic elements (not visible) of a transducer probe according to the present invention which may have a protective sheath (not shown) disposed between the probe  1361  located toward the distal tip  1360 . All distances if any are shown are approximate and may be changed for different applications such as reaching the heart pericardial sac (also known as the pericardial space) versus reaching a melanoma close to the skin or a kidney with an anterior approach with optimized resolution and are shown in millimeters. A convention used in the brief and detailed description is that a reference numeral YXX may be used wherein the Y provides the Figure number where the element first appears and the XX (which may be any two-digit number) may represent the reference numeral of the element (used consistently for a similar component), for example, transducer array  1362  comprises Y for  FIG.  13    and XX for numeral  62  which represents the transducer array while element  1310 A represents the cylindrical housing  1310 A shown in  FIG.  12    held within disposable sheath, for example,  1109  by a surgeon (not shown in this figure series). To the left of  FIG.  13   , is seen a cross-section of a plane of housing  1310 A including both the probe  1361  and the cylindrical housing  1310 A. At the right of  FIG.  13    is shown a cross-section  1340  intended to show the radially placed elements of the outer cylindrical housing  1310 A, cable transition portion  1206 B, the strain relief feature and the cable  1206 A including, for example, the twenty-three leads to the transducer linear phased array, shown by way of example, which in turn leads to a display processor and display. Views  1361 ,  1362 ,  1316  are shown enlarged as  FIGS.  14 A  (end view) and  14 B (cross-sectional top view) of exemplary linear phased array elements  1462 - 1  through  1462 - 23 . 
         FIG.  14 A  shows a first exemplary embodiment of a front view of an exemplary ultrasound linear phased array having, for example, twenty-three linear elements  1462 - 1  through  1462 - 23  of, for example, 0.1 millimeters pitch (approximately one lambda wavelength of an exemplary center frequency of fifteen megahertz) making a total array  1362 ,  1462  of about 2.3 millimeters by 2.3 millimeters. A ½λ embodiment may also be used as is known in the art with the complication that the number of elements of the array may increase the size of a cable to a processor and display (not shown). Not shown in  FIG.  14 A  or distal tip  1360  of  FIG.  13    is that the linear phased array may be protected within a dome, flat window, no window, or tapered window of the housing including the needle guide and when actuated generates an image plane discussed above with intersects with a needle delivery port of a needle guide so as to capture an image of any needle/syringe/sheath/tool emerging into the imaging plane. A probe shaft cylindrical housing  1410 A ( FIG.  14 B ) is seen that may have a circular cross-sectional shape that is approximately four millimeters in diameter as seen in  FIG.  13   . Not shown, the probe shaft cylindrical housing  1410 A may contain electrical leads to the linear phased array transducer array  1362  and an accelerometer and/or one or more gyroscopes having signal leads which will align any image on a display with the gravitational field of the earth. One transducer array may be replaced with another transducer array having a different center frequency and similar one lambda pitch and still fit within the outer probe housing diameter, for example, four millimeters. A more conventional ½λ pitch may be used in alternative embodiments, a possible problem being the number of diameter of leads forming a cable from the distal to the proximal end of the catheter. The array  1362  may comprise individual linear phased array transducer elements comprising a one by twenty-three linear array shown as elements individually numbered  1462 - 1  through  1462 - 23 . The white area between the linear phased transducer array  1362  and the housing  1361  is un-numbered and comprises a potting material  1464  seen best in top-down cut-away view  FIG.  14 B . As described above these array elements  1462 - 1  through  1462 - 23  for different center frequency may be contained within a probe insertable into a disposable outer housing,  FIGS.  1  through  12 I  so that transducer arrays may be exchanged for different applications of the probe. 
         FIG.  14 B  shows a top sectional  1460  comprising the distal tip and, in particular, comprises from left to right a cross-hatched probe shaft housing  1410 A, an array potting material  1464  to firmly grasp the linear phased array elements  1462 - 1  through  1462 - 23  ( FIG.  14 A ). Below the section  1460 , there is seen at the center of the probe shaft housing  1410 A, an aperture for conducting an electrical signal cable  1465 , narrowing the signal cable  1465  from the diameter of cable channels to piezoelectric elements  1462 , the leads carrying signals to/from the linear phased array elements  1462 - 1  through  1462 - 23  via the array backing  1463 . The aperture is preferably walled as shown and extends the entire length of the probe shaft housing, carrying the electrical cable  1465 . 
         FIG.  15 A  is a blow-up of the left side cross-section of  FIG.  13   . There is a section labeled  1216  intended to represent a thicker portion of the hollow cylindrical housing  1310 A of  FIG.  13   . A pair of broken lines, perpendicular to one another signifies the center of the cylindrical housing  1310 A. Similarly, a pair of solid lines perpendicular to one another signifies the center of the probe shaft housing in circle A such that the distance between the two centers may be approximately six millimeters and the diameter (shown as a single line and arrow tip) of the cylindrical housing  1310 A may be approximately 17.5 millimeters. 
         FIG.  15 B  is a blow-up of detail A of  FIG.  15 A  showing the relationship between the linear phased transducer array  1462 , its probe shaft  1461  which may comprise potting material  1464  and the outer wall  1416  of the cylindrical housing  1310 A. The partial circular line is intended to show that wall  1416  only represents a portion of cylindrical housing  1310 A and should not be considered a part of the image guided probe which may be reusable and removable from the outer sheaths depicted in Figures described above. 
         FIG.  16    provides either a top-down view or a bottom-up view of the image guided probe at the center of  FIG.  13    (without showing details of any sheath for protecting the probe so that the probe housing is reusable). The view shows the probe  1350 &#39;s distal end  1360  where would be located the linear phased transducer array  1462  of the present invention. The center section is the cylindrical housing  1310 A that is covered by a disposable sheath that may be grasped and utilized by a surgeon. The section transition feature  1315  provides a side view of an example transition between the probe&#39;s cylindrical cable housing  1310 A and the cable strain relief feature  1306 B which provides the exit of cable  1306 A from the imaging probe for image processing and display. 
         FIG.  17 A  is a left front perspective view of an image guided probe comprising distal probe end  1360 , probe shaft  1350 , cylindrical housing  1310 A, transition feature  1315 , flexible cable section  1306 B and cable  1306 A from left to right. 
         FIG.  17 B  is a right rear perspective view of an image guided probe showing the same components in the same order as is seen in  FIG.  17 A  from upper left to lower right. 
     
    
    
     These and other echogenic shapes of needles, sheaths and tools for imaging in parallel via a parallel ultrasound transducer are described in U.S. provisional patent application Ser. No. 62/526,170 filed Jun. 28, 2017, incorporated by reference as to its entire contents. Imaging may also be improved using a known contrast agent during a procedure if the needle, syringe, sheath or tool penetrates the skin tissue so that blood vessels may preserved from puncture as a tool is guided toward a region of interest. 
     Thus, there will be described in the following detailed description a plurality of embodiments and features of an image guided catheter or probe of the present invention with removable, replaceable and reusable imaging assemblies and removable, replaceable instruments for performing minimally invasive medical procedures as will be explained further herein. 
     DETAILED DESCRIPTION 
     The aspects summarized above can be embodied in various forms. The following description shows, by way of illustration, combinations and configurations in which the aspects can be practiced. It is understood that the described aspects and/or embodiments are merely examples. It is also understood that other aspects and/or embodiments can be utilized, and that structural and functional modifications can be made, without departing from the scope of the present disclosure. 
     Minimally invasive procedures provide physicians with access to internal organs and structures via a small number of incisions in the patient&#39;s body. Minimally invasive procedures are generally preferable over open procedures because they require only small incisions, thus reducing trauma to the body, lessening recovery time, and reducing costs. The medical instruments used in performing such procedures are generally similar to those used in open surgical procedures except that they include an extension such as a tubular extension of small outer diameter between the patient end of the instrument entering the surgical field (i.e., the operable end of the tool, instrument or device) and the proximal end portion having a large outer diameter gripped by the surgeon, the tubular extension at the distal or patient end being tapered or having a viewing dome and containing an imaging assembly lumen and at least one other lumen, for example, for an introducer needle having a solid pointed tip, a biopsy or other needle, sheath, syringe or other tool or instrument of various types once the operating site is reached. 
     Typically, minimally invasive procedures may involve up to five incisions up to one inch in length. The treatment area is then accessed by inserting one or more cannulas or sleeves through the incisions to provide entry ports through which instruments are passed. Alternatively, access to the treatment area can sometimes be obtained using a natural body opening such as the throat, nose, ear canal or rectum or via a vein. In procedures using this approach, a cannula or sleeve may be inserted into the bodily opening and surgical instruments are passed to the treatment site, either through the cannula/sleeve or directly through the body opening or vein. 
     While minimally invasive procedures provide numerous advantages over open procedures, they generally do not provide a physician with a direct view of the targeted sites. Further, many parts of the anatomy are rather complex and/or small and thus require particular precision and delicate handling. It is therefore desirable to provide precise imaging techniques for use during minimally invasive procedures. 
     In general, the illustrated embodiments and aspects provide an image guided catheter/probe device that couples an imaging system within an imaging lumen and an instrument delivery system and/or minimally invasive interventional device within a further lumen or channel (such as the needle channel  103  of  FIG.  1   ) open from the proximal end to the tapered or flat distal end. The instrument delivery system can include, for example, delivery of materials to or from a target site or delivery of instruments and devices to a target site, depending on the application. 
     In accordance with aspects described herein, an ultrasound imaging device of this invention can comprise one or more small ultrasound transducers integrated into an imaging transducer assembly exemplified by a linear phased transducer array, either as forward-directed transducers for direct, head-on imaging or combined with one or more side-directed transducers (as taught in priority patent applications and issued patents of inventor Dr. Abraham) which can provide additional imaging or other ultrasound applications such as delivery of heat to a target site within the patient. In addition, such ultrasound imaging can also be combined with all-optical high-resolution transducer imaging such as optical coherence tomography imaging and/or provide optional optical imaging through the use of one or more fiber optic bundles disposed though the imaging transducer probe and cable assembly in additional imaging lumens (not shown) but discussed in priority applications and patents. 
     For example, a first low resolution, long range ultrasound imaging transducer assembly may be used with an introducer needle to subcutaneously enter a patient. This assembly may be replaced with a higher resolution, short range imaging transducer assembly as the target site is reached in real time. Once the site is reached, a further high resolution, short range assembly may be introduced through the imaging lumen or channel which may comprise an optical coherence tomography device which operates on an echo principle similar to that employed by ultrasound. One or more minimally invasive medical procedure applications will be discussed herein. 
     An imaging system in accordance with aspects and features described herein can guide and facilitate many different procedures, thereby significantly assisting in the access of and performance of procedures on organs, structures and cavities within the body, particularly during minimally invasive procedures. The described devices and methods are compatible with all surgical and diagnostic devices and will allow bedside emergency procedures. Ultrasound provides particular benefits because it is biologically safe and uses non-radiating energy to provide detailed anatomic and, in some cases, functional images. The images generated by devices described herein can provide a user with direct vision within the body in real time. Further, both ultrasound and optical coherence tomography provide a user with visualization of structures as well as within and beyond nearby structures (such as the pericardium) to perform procedures such as a cardiocentesis. 
     In certain embodiments, the device may comprise an ultrasound imaging catheter/probe that incorporates one or more variable frequency ultrasound transducer assemblies that replace an original transducer assembly operating at one or more frequency ranges within the frequency range of from twenty kilohertz to, for example, several hundred megahertz; (however, the wavelength of such a low frequency may require the probe housing to have a large diameter unsuitable for subcutaneous probe insertion). Optical coherence tomography may provide further imaging at radio frequencies, for example, in the infrared. In one preferred embodiment, one selected frequency range of one replaceable transducer assembly of a center frequency may be from ten to forty megahertz (fifteen megahertz center frequency shown). However, various frequency ranges of the replaceable ultrasound transducer assembly can be used for different purposes and provide different beneficial results. Frequencies in the lower range, for example, below one megahertz, and particularly in the 100 to 200 kilohertz range, can be used, for example, to provide heat therapy or to treat conditions such as blood clots and provide low resolution, long range imaging. Frequencies above one megahertz can be used to provide higher resolution, short range imaging. For example, frequencies in the 25 to 30 megahertz range can be used to image organs such as the eye or can be used to provide imaging of small animals. Even higher frequency ranges, for example, ultrasound frequency ranges in the one hundred to several hundred megahertz frequency range, can be used to provide very high-resolution imaging, sometimes known as high-frequency ultrasound microscopy. This and optical coherence tomography may achieve sub-micrometer resolution for use in very close target sites such as at a heart valve with minimally invasive surgery replacing prior art open heart surgery. A further operation for placing, for example, for placing a heart pacemaker may now employ the present invention to place the pacemaker directly on the pericardium rather than utilize a wire and hook device to deliver an electric pulse to the heart as is now commonly used. Now the image catheter devices will be further discussed with respect to potential applications. 
     Devices and methods such as are described herein are suitable for use in a variety of medical procedures. In certain embodiments, the image guided catheter device may comprise conventional catheter applications including, for example, biopsy catheters, ablation catheters, and mapping catheters, in combination with the novel imaging aspects of replaceable imaging frequencies and instruments imaged by the imaging components described herein. In other embodiments, the device can comprise one or more interventional devices (e.g. syringe, forceps, biopsy instruments, clamps, MEMS manipulators, retractors, etc.) that may be compatible with an imaging catheter/probe such as a biopsy catheter, ablation catheter, mapping catheter, or other form of sheath having larger diameter lumens. In some embodiments, the device can also be compatible with instruments such as video-scopes, external wired or wireless ultrasound imaging and delivery needles such as those used for stem cell therapy or implanted ultrasound devices which may utilize wireless transmission of ultrasound data for supplemental viewing of a surgical site. In still other embodiments, the devices may be compatible with fiber optics such as those used for vision therapy as well as optical coherence tomography. U.S. patent application Ser. No. 11/871,219 filed Oct. 12, 2007 (now U.S. Pat. No. 8,147,413 issued Apr. 12, 2012, Ser. No. 12/182,247 filed Jul. 30, 2008 (now U.S. Pat. No. 8,038,622 issued Oct. 18, 2011), Ser. No. 12/283,779 filed Oct. 14, 2008 (now U.S. Pat. No. 8,147,414 issued Apr. 3, 2012), Ser. No. 12/700,066 filed Feb. 4, 2010 (now U.S. Pat. No. 8,235,903 issued Aug. 7, 2012), Ser. No. 13/847,902 filed Aug. 22, 2013 (now U.S. Pat. No. 9,149,257 issued Oct. 6, 2016) and Ser. No. 13/973,476 filed Aug. 22, 2013 (pending) all by Theodore P. Abraham are incorporated by reference as to their entire contents, and all medical devices and applications described therein may be adapted for use with the present invention and, for example, adapted to fit through the needle/instrument lumen or channel or other additional lumen (not shown) of the present invention&#39;s expendable housing part (for example, per  FIG.  1 A ). Furthermore, all other features and functionalities described in all these patent applications may be incorporated into and may be combined with embodiments of the present invention. 
     The devices and methods of various embodiments of an imaging catheter such as those illustrated in  FIGS.  1 A- 17 B  and described herein can be used in various minimally invasive surgical procedures and in other diagnostic and therapeutic applications. One skilled in the art will appreciate that the aspects and embodiments of an imaging catheter/probe as described herein, although advantageously suited for such procedures on humans, can have other uses, such as for veterinary procedures and open medical techniques as well as minimally invasive procedures in humans or used externally or in body orifices. Further, while the devices of the present invention are described with particular reference to catheters/probes, this shall not be construed as limiting the devices to these embodiments, as it is contemplated and thus within the scope of the illustrated devices to adapt the devices described herein so as to be in the form of any type of minimally invasive or non-invasive device and sized for use for a medical procedure involving any body organ or structure (e.g. using syringes, sheaths, wires, forceps, biopsy instruments, clamps, retractors, micro-electronic motors (MEMS), etc.). 
     Further, while certain devices, systems and methods are described herein with particular reference to pericardial access devices, systems, and methods, this shall not be construed as limiting, as it is contemplated to adapt the devices, systems and methods described herein so as to be used in any of a number of procedures, including, but not limited to: various cardiovascular procedures; general micro-surgery; biopsy, drug and device delivery; vascular procedures; urology; thoracic procedures; otorhinolaryngology (ear, nose and throat); orthopedic procedures; neurosurgery; gynecologic procedures; gastroenterologic and general procedures; colon and rectal procedures; pericardiocentesis; thoracentesis; ascites tap; ventricular lead placements; and electrical and electro-mechanical mapping of the heart. As such, it is contemplated that the specific design parameters, (such as length of the distal end having parallel imaging and needle/instrument channels) and other characteristics set forth hereinafter, and methods in relation thereto can be modified to provide appropriate dimensions and geometries as required to perform such other techniques. For example, the length and diameter of the device as herein described is adapted to suit the particular conditions for a given procedure. Thus, the disclosure to follow should be considered illustrative only and should not be construed as limiting in any configuration of a device as described herein. 
     The device may be used to provide a three-dimensional mapping system solely using an incorporated ultrasound system or in connection with other imaging modalities such as optical coherence tomography, computed tomography, magnetic resonance, or videoscopy. When the device is in the form of a catheter, probe or sheath, this will allow stereotactic and remote/robotic operation of devices inserted and manipulated through the device. In such a system, an imaging modality (ultrasound, OCT, CT or MRI) can be used to generate a three-dimensional image on one of a plurality of two-dimensional screens. The device can interactively use the generated images to be directed either manually or through an automated or semi-automated process for deployment to a target area displayed in composite three-dimensional images from various views. The device can be used in connection with an ultrasound or OCT display system (B mode image or 3D image) that interfaces with the device to produce and display the images. 
     By way of introduction, a fully assembled imaging device  1000  of the present invention is depicted in  FIG.  10 A- 10 I ; (needle or syringe handle  1010  and needle  1011  first shown in  FIG.  10 A ). The present invention includes new embodiments of the imaging catheter of U.S. Ser. No. 14/865,151 filed Mar. 24, 2015 (now allowed) and U.S. Ser. No. 13/847,902 filed Mar. 20, 2013 (now U.S. Pat. No. 9,149,257) with several new features and alternative embodiments in its design. In the present invention, the transducer element may be placed close to but separate from the introducer needle (or a syringe) so that either the one or the other may be removed and replaced at any time with another element/instrument according to the needs of the surgeon. The imaging assembly lumen or channel contained within probe section  1002  ( FIG.  10 B ) and the needle/instrument lumen or channel  1003  located above an ultrasonic probe housing  1002  are placed in the center and top of the distal end of the device respectively. The ability to change imaging assemblies at will in real time during a procedure enables higher fidelity imaging as the operating site within a body is approached during a procedure by a needle, syringe tool or sheath within, for example, needle channel  1003 . In one embodiment of the present invention as shown in  FIG.  1 A , the image quality may be improved by placing a vertical window  105  at the end of the imaging lumen or channel instead of an angled (or tapered) window or a dome which may be used in the alternative and may expand the imaging zone to hemispheric proportions. Another important new feature is a reusable imaging transducer comprising a linear phased array ( FIG.  14 A ) contained in a separate imaging transducer assembly probe section insertable into a probe housing and top-mounted needle guide (for example,  FIG.  1 A  or  FIG.  8 A or  8 B  that opens from the top, each transducer assembly operating at a desired ultrasound or optical coherence frequency range. The image guided catheter/probe device of the present invention comprises an expendable housing  102 ,  202 ,  502 ,  809 ,  909 ,  1009 ,  1109  with a proximal cable end  1006 A proximal to the healthcare professional using the device, a distal tip  104 ,  204 ,  904 ,  1004  having an introducer needle, syringe or tool  1010 ,  1011  for insertion of the device into a patient&#39;s body or just the needle/syringe which is replaceable with other instruments, an imaging lumen or needle channel  103  that may open to release the needle/tool/instrument. In other words, the present device may be used subcutaneously, in a body orifice or external with just a needle puncture to introduce, for example, a biopsy needle or syringe. 
     In the image guided catheter/probe device (for example,  FIG.  10 A  of the present invention), the distal housing, syringe and needle guide may be disposable and the imaging transducer assembly (more expensive) replaceably introduced through an imaging lumen channel in sheath  1009  and probe housing  1002  and may be removed and reused, separated from the device and cleaned if necessary. To reuse an imaging transducer assembly, for example, the front-end assembly seen in  FIG.  14 A , may be covered by window (for example, distal tip window  105  of  FIG.  1 A  being disposable, removable and plastic or uncovered but protected within the distal probe housing while in use and sterilized between uses. The present invention is designed such that the imaging transducer assembly may have a curved cable shape that fits into a lengthwise slot on, for example, the left (or right) side, top or bottom, of the housing barrel, allowing the transducer assembly to slide into the imaging channel or probe housing  1460 . The present invention may also include locking mechanisms or tabs (such as locking tab  101 ) to temporarily secure the imaging transducer assembly. The syringe/needle assembly has a needle channel that is opened either via a tab  106  ( FIG.  1 A ) or via a sleeve lock  823  ( FIG.  8 A ) to the proximal cable end  1306 A of the reusable housing  1006 A,  1006 B,  1006 C ( FIG.  10 C ) which may reside in disposable sheath  1009 . 
     The reusable imaging ultrasound transducer assembly section  1006 A,  1006 B,  1006 C assembly may also be freely removed and replaced at any time during a procedure. For example, a lower-frequency transducer assembly  1462  adapted to produce images at a lower resolution but greater depth into the body may be used to find a target site in a patient&#39;s internal target organ. Once the target site is found, the user can remove a lower-frequency range transducer assembly and replace it with a higher-frequency range transducer assembly  1462  such as an OCT assembly to produce a higher-resolution image at the target site (with three dimensions) allowing the user to obtain an improved quality image or sequential series of images while performing a procedure. 
     The expendable housing, for example, housing  102 ,  809 ,  909 ,  1009  may be a variable outer diameter rigid plastic sheath with a diameter in the range of 1-20 French, with current preferred embodiments in the 10 to 14 French range (3.3667 to 4.6667 mm diameter) for tight work or much larger diameter such as 20 millimeters for larger work or to carry more imaging capability. The imaging channel  1465  ( FIG.  14 B ) may have a larger outer diameter than that of the syringe/needle channel, for example channel or guide  103  or  903 . The probe barrel which may enter a patient subcutaneously may be any length depending on the approximate distance of travel from a skin insertion to a target site. The imaging ultrasound transducer assembly  1362  ( FIG.  13   ) may comprise a forward viewing phased array probe with a variable field of view depending on the specific array. The imaging transducer assembly  1362  may comprise an ultrasound or OCT transducer at the distal end (as seen in  FIG.  14 B ) with variable frequency, variable cross-sectional diameter, and a variable number of transducer elements or optical fibers located in a steel or rigid plastic cylinder inside the expendable housing for the reusable housing with a variable outer diameter at the proximal end and narrow diameter at the distal end. Examples of possible arrangements of transducer elements at the tip of the transducer are depicted in U.S. application Ser. No. 13/847,902, FIGS. 5A, 5B, and 5C. The present invention encompasses transducer assemblies  704  with center frequency ranges in the ten to forty megahertz range (fifteen megahertz center frequency shown), with a current preferred range of ten to twenty-five megahertz for use in traveling from external skin tissue (or the exterior of the eye) to one to five centimeters beneath the skin. Wide band OCT imaging may be performed as white light imaging as well as a narrower band near infrared imaging. However, the frequency ranges may vary depending on the particular application for which the imaging device is used. 
     The length dimensions of the probe barrel of the device are not particularly limited and can vary depending on the ultimate use of the device, the insertion point, the obesity of the patient and the distance to the target area from the insertion point (if insertion is required). The length of the device may vary depending on the application, but a preferred range is between one to four inches to be used, for example, for vascular applications, ranging up to twenty inches (ten inches for the proximal or surgeon end and ten inches for the distal end) to be used, for example, to perform procedures on the liver. The diameter and length of the tapered, flat or domed end near, for example, the distal tip  105  of the housing  102  can be affected by the size of an anatomical structure in which it is to be inserted. For example, the tapered, flat or domed distal end  105  can be of greater radius, longer or more slender for deep abdominal structures such as the kidneys or pelvic structures such as the ovaries or uterus, or can be shorter and wider for delivery of devices into more shallow structures such as a joint, muscle, the liver, or the heart. The diameter of the distal end can also be affected by the desired size of the incision through which device  1000  is inserted and which must subsequently be closed. The diameter of the distal end  105  of the probe housing can also be affected by the purpose for which the device is used. For example, the diameter of the distal end can be smaller for aspiration of fluids from a target site or larger if additional ports or device/medication delivery are desired. 
     For example, when device  1000  is in the form of a vascular sheath (not shown), the outer diameter can vary depending on the targeted blood vessel through which the distal tip  105  is inserted. In an embodiment, device  1000  can be in the form of vascular sheaths (not shown but exemplified in priority applications and patents) used during cardiac procedures and can be inserted through a blood vessel in the upper thigh or, alternatively, can be inserted through a blood vessel in the arm. In another embodiment, alternative devices  1000  can be inserted by anesthetizing an area of the patient&#39;s upper thigh and inserting the distal end  105  (if of sufficiently narrow diameter) through a blood vessel in the upper thigh and towards the heart. In this embodiment, the distal end  105  can have a length sufficient to traverse this pathway, a diameter small enough and material flexible enough to be inserted into a blood vessel and advanced through the blood vessel to a target site. In an additional embodiment, the front end of the imaging transducer assembly  1362  may be housed in a flexible material that would allow the front end of the ultrasound transducer to advance longer distances through a blood vessel along with a flexible distal end of the image guided catheter device  1000 . In a further embodiment, device  1000  can have an introducer needle  1011  integrated (not shown) therein (without using a syringe), which can enable device  700  to penetrate directly into the chest wall of a patient for direct access to the heart without the need for access through the vascular system. A cardiocentesis may be performed in this way using an introducer needle  1011  followed by a syringe  1011  once the heart is reached and the introducer needle replaced with the syringe to alleviate some excess body fluid in the pericardial space. 
     Device  1000  can also be in the form of a sheath (not shown) used, for example, during a laparoscopic procedure, and in such a case, the distal (patient) end  105  can generally have an outer diameter in accordance with conventional laparoscopic sheaths and will have a length that provides access to the target site. 
     Further, the device can be used as a minimally invasive conduit from the skin surface to the target site to allow passages of catheters, guide wires (not used in the depicted embodiment  1000 ), and other instruments through distal tip  104  of the depicted needle guide, and the distal tip  104  can be sized to allow these various instruments to be passed therethrough. The user of the device may change the imaging transducer assembly  1462 - 1  through  1462 - 23  as needed during a procedure to obtain a better image, and the user may also change the instrument contained in the needle channel  103 ,  1003  as needed to perform the procedure. 
     In an exemplary embodiment described in more detail herein, device  1000  can be in the form of an image guided catheter  1000  that can be introduced through the chest, side or back to access various internal structures using minimally invasive techniques. As such, the distal end  104 ,  105  can have an outer diameter ranging from about 1 F to 15 F (wherein 1 F=0.33 mm) up to about six millimeters and a length ranging from about 1″ to 20″. Specific lengths and diameters can be provided based on the insertion site of the catheter/probe, the distance to the desired target site(s), the obesity of the patient and the space required for insertion of one or more interventional devices through the distal (patient end) tip  104 . 
     In other embodiments, device  1000  can be in the form of any interventional device that can be, for example, inserted through a sheath (not shown) or catheter to access various internal structures using minimally invasive techniques. As such, the distal tip  104 ,  105  can have an outer diameter sized so as to fit within conventional sheaths or catheters, and a length suitable to access the desired target site(s) through the sheaths or catheters. 
       FIG.  1 A  depicts a view of a patient or distal end of an image guided catheter device assembly which may be referred to herein as a barrel (as distinct from a larger diameter proximal end, not shown) in accordance with one or more aspects described herein,  FIG.  1 A  showing a replaceable introducer needle/syringe/instrument channel/lumen having a distal tip  104  visible in an imaging zone of a replaceable transducer element  1362  ( FIG.  13   ) replaceable as higher resolution is needed when the access instrument reaches the operating site if used subcutaneously. As shown in  FIG.  1 A , the ultrasound or OCT transducer or other known vision element being the distal tip  105  of the device  1000  at the patient end has an imaging zone desirably encompassing the tip of the introducer needle  1011  (typically pointed) or biopsy needle or syringe (typically hollow) as it emerges from guide or channel  103 .  FIG.  1 A  shows an introducer needle lumen or channel  103  of a needle guide mounted above an ultrasound or OCT imaging lumen or channel ending at tip  105  that is captured by a imaging plane of an ultrasound transducer array; (see  FIGS.  9 E,  9 I ). The removable, replaceable imaging transducer assembly  1362  (not shown) may be inserted into the imaging probe barrel as will be discussed herein in real time during a medical procedure. To reduce ultrasound deflection during use of the device, as seen in  FIG.  1 A , the imaging system can be provided with matching layers disposed, for example, adjacent the front face of transducer elements. Matching layers can facilitate the matching of an impedance differential that may exist between the high impedance transducer elements and a low impedance patient. The structure of matching layers can generally be in accordance with conventional matching layers and generally can include a matching layer front face and a matching layer rear face, and can optionally include a pocket with matching material that can reduce ultrasound deflection. Suitable matching layer materials can include, for example, plastic materials such as polysulfone or REXOLITE® (a thermoset material produced by crosslinking polystyrene with divinyl benzene, available from C-LEC Plastics, Inc., Beverly, N.J.). 
     The imaging system may further include a backing layer (not shown) in accordance with conventional backing layers. The backing layers can generally be coupled to the rear face of the transducers  1462 - 1  through  1462 - 23  ( FIGS.  14 A and  14 B ) and function to attenuate acoustic energy that emerges from the rear face of the transducer elements. Generally, such backing layers can have a front face and a rear face, and can be fabricated of acoustic damping material that possesses high acoustic losses. 
     Transducers can be of a size and composition in accordance with conventional transducers. For example, in some embodiments, the transducer elements can comprise natural piezoelectric materials such as quartz, topaz, or tourmaline group minerals or can comprise man-made materials such as PZT ceramics or piezoelectric polymers such as Polyvinylidene fluoride (PVDF). In other embodiments and for high resolution and all-optic ultrasound transducer is useful. Transducer elements can also be of any suitable size, with such size being limited by the desired size of the housings used and the use which is being made of the ultrasound, i.e., for imaging or therapeutic purposes. 
     In currently preferred embodiments, as many as 20-96 channels (twenty-three by way of example) may be provided from the ultrasound transducer array to the display output device through the ultrasound transducer and cable assembly. However, further embodiments of the transducer assembly may contain anywhere from one to 2000 ultrasound imaging channels, with a greater number of parallel channels possible as ultrasound imaging technology progresses toward smaller elements such as, for example, fiber optics. Moreover, known contrast agents may be introduced through a hollow needle or sheath lumen through a blood vessel and may be known to adhere to, for example, human muscle tissue or a heart valve or other organ of interest to improve echogenicity just as the needle, sheath or a tool may have an echogenic surface such as a spirally wrapped wire round the needle or syringe. 
       FIG.  1 B  depicts a top view of a needle guide  103  of  FIG.  1 A  to show how guides  121  and  122  guide a needle or tool into a needle channel and can rest on needle buttons  107 A and  108 A of one side of the needle guide  103  and also rest on needle buttons  108 A and  108 B of the other side of the needle guide.  FIG.  1 A  disposable housing and needle guide is operated by tab  106  to rotate one half of a needle guide to match with the other half. 
       FIG.  1 C  depicts an open front view of the needle guide  103 . A needle (syringe or tool) may be moved out of the needle guide  103  due to opening guides  121  and  122 . Button tabs  107 A and  107 B along with button tabs  108 A and  108 B help extricate the needle from the needle guide  103  from above. Such an open needle guide precludes the collection of material which may adhere to a needle or syringe or other bodily material at the needle guide end  104  when the needle is removed through a closed needle guide. 
       FIGS.  2 A and  2 B  depict different cross-sectional views of the patient or distal end of the embodiment of  FIG.  1 A  where tab  106  for closing the needle channel is now referenced as tab  206  for opening the needle channel  203  of an imaging device in accordance with one or more aspects described herein. When tab  206  is manipulated in a clockwise direction, the needle channel is closed around a needle/syringe/tool not shown or opened to allow vertical removal.  FIG.  2 B  shows additional button tabs  209 ,  210  which may be used or not used in a given embodiment to further serve to support a needle/syringe/tool in needle channel button tabs; (see  FIGS.  1 B and  1 C ). Needle channel tip  204  may be tapered and may receive and permit a tapered tip hollow needle (possibly of a syringe) to exit the needle guide at tip  204 . Sensor channel tip  205  may indicate the location of an ultrasound sensor not seen which may be directed forward and provide forward-imaging of a needle/syringe/tool in the needle channel  203  as it extends into a forward imaging zone of a transducer array (such as array  1362  of  FIG.  13   ). In either figure, a rear tab  101 ,  201  may lock a sensor and cable section assembly in place within the body  202  comprising a sensor channel (transducer assembly and cabling). Needle  1010  and sensor and cable assembly  1006  are first seen in  FIG.  10    locked in place by tab  1001 . 
       FIG.  3 A  provides an enlarged front-end view of the tab  106  now seen as tab  306 A which may move between positions  309  and  310  to open or close the needle channel. In  FIG.  3 A , the needle channel tip  304 A is shown closed. 
     In  FIG.  3 B , the needle channel tip  304 B is shown open. Similarly, a first part of the needle channel  321 A is shown closed in  FIG.  3 A  and the same part of the needle channel  321 B is shown open in  FIG.  3 B . Sensor channel  302  of either of  FIGS.  3 A and  3 B  carries the sensor and cable to the sensor channel tip  305 . A second part of the needle channel  322 A or  322 B remain stationary where line  320  represents the line along which the needle channel opens. Section A-A extends from the top of the needle channel through the sensor body  302 . 
       FIGS.  4 A and  4 B  depict details of the opening and closing of a needle channel using circularly moveable tab  106  where  FIG.  4 A  represents a closed needle channel and  FIG.  4 B  represents an open needle channel, for example, where partial circular sections connected to tab  106  comprise line  420  along which the needle channel opens.  FIG.  4 A  comprises closed needle channel tip  404 A, the first part  421 A of the closed needle channel, the second part  422 A of the closed needle channel, and the sensor channel tip  405  of the ultrasound sensor channel. Referring to  FIG.  4 B , sensor channel tip  405  is in the center. Surrounding this center  405  are open needle channel tip  404 B, open second part  422 B of the needle channel and open first part  421 B of the needle channel. Section C-C is taken just of the probe housing as seen in  FIG.  1 A . 
       FIGS.  5 A and  5 B  depict in rear perspective view a closed needle channel  504 A ( FIG.  5 A ), button tabs  507 ,  508 , and closed needle entry  503 A ( FIG.  5 A ) leading to distal closed tip  504 A ( FIG.  5 A ) of the needle channel sensor channel tip  505  (seen in both  FIGS.  5 A and  5 B ). The sensor body  502  in both  FIGS.  5 A and  5 B  has a flexible locking tab  501  for allowing a sensor probe and cable assembly to be placed within the housing per  FIG.  10   . Closing tab  506 A in  FIG.  5 A  shows a close position for the needle guide while closing tab  506 B in  FIG.  5 B  shows an open position for the needle guide as per open needle guide  503 B. Distal tip  504 A is shown closed in  FIG.  5 A  and open tip  504 B is shown in  FIG.  5 B . Circle D shows the difference between closed needle guide  503 A ( FIG.  5 A ) and open needle guide  503 B ( FIG.  5 B ) where opening and closing uses tabs  506 A (closed) and the same tab  506 B in an open position. 
       FIGS.  6 A through  12 I  show an embodiment similar to the previously discussed embodiment whereby a sleeve lock is used to lock two halves of a needle channel of a needle guide together around an inserted tool: needle, syringe or other tool. Normally, the needle guide is open but may be closed by a sleeve lock as discussed herein. 
       FIGS.  6 A and  6 B  depict front perspective views of the line  620  along which the needle channel  603  opens along with a portion of the sensor housing or body  602 . Referring to  FIG.  6 A , needle channel  603 A is in a closed position, the first part of the needle channel  621 A is closed as is the second part (for example, half) of the needle channel  622 A. Referring now to  FIG.  6 B , the needle guide is in an open position  603 B and the first and second parts  621 B and  622 B (for example, halves) of the needle channel are opened to their normally open position. 
     Thus far, we have discussed how a tab  106  may open and close a needle channel. In  FIGS.  7 A through  8 H  and in  FIG.  9 A  an alternative to a tab closure is shown that comprises a sliding groove  724  moved by a surgeon via a circular or partially circular tab or sleeve lock  723  with unnumbered finger grips seen as rounded gripping ridges on the sides of the sleeve lock  723 . 
       FIG.  7 A  shows sensor housing channel  702  and the needle channel  703  in a closed position where the circular tab or sleeve lock  723  and groove  725 A have been slid forward to clasp the two halves of a needle guide  703  together. The groove may have parallel sides shown or have V-shaped clasping sides (not shown). The parallel sides  721  and  722  ( FIG.  7 B ) of groove  724  may have a corresponding quarter-circular portion  725 A which gathers the two sides  721 ,  722  of the needle guide together, and the groove  724  holds the needle guide together. A retaining spring tab  712  retains the sleeve lock so as to close the needle channel  703 . Any circular arc  725 A may mate with a similar arc to close the normally open needle channel  703  in groove  704 . Another example is an approximately forty-five degree angle on each of the groove  724  as  725 A and the halves of the needle guide  703 . 
     In  FIG.  7 B , it may be seen that a matching quarter-circular portion  725 B matches portion  725 A and so, when they meet as the tab  723  is closed, the two sides  721 ,  722  of the needle guide  703  are caused to collapse and be held by together by the groove  724  via sleeve lock  723  as seen in  FIG.  7 A . As already discussed, a quarter circle is shown but may be another arc of a circle or a cut at, for example, a forty-five degree angle. 
       FIG.  8 A  depicts a top down view of the groove closure of  FIGS.  7 A and  7 B . As already seen, sensor housing  809  has a locking tab  801  for linking with a sensor and cable assembly seen in  FIG.  10   . Needle guide  803  is seen held closed in a groove and is so held in a closed position as long as the groove grips the halves of the needle guide  803  together. Flexible retaining tab  812  holds sleeve lock  823  closed also closing needle channel  803 . 
       FIG.  8 B  provides a side cross-sectional view of the sensor and needle guide assembly shown in top view in  FIG.  8 A . Sensor  802  has a flexible locking tab  801  for linking to an internal transducer and cable assembly per  FIG.  10    as seen in  FIG.  8 A  in top view. Needle guide  803  is shown closed with button tabs  807  and  808  for supporting a needle, syringe or other tool. A flexible retaining tab  813  prevents a sleeve lock  823  from opening any further than its raised edge. 
       FIG.  8 C  depicts an expanded view of the closing groove mechanism (Detail B) for closing the needle guide first and second parts  821  and  822  along line  820  via quarter-circular groove portions  825 A and  825 B (or other circular arcs or forty-five degree cuts) so that sleeve lock  823  in a forward position closes the normally open needle guide halves within the depicted groove  824 . 
       FIG.  8 D  shows a side view similar to the side cross-sectional view of  FIG.  8 B . The sensor channel  802  is seen at the distal end and the tab  801  at the proximal end. The finger grip  823  is shown extended so as to force the needle channel  803  closed with button tabs  807  and  808 . 
       FIG.  8 E  is a front perspective view of the sensor housing of  FIG.  8 D . An ultrasound sensor channel  802  is located below the needle channel indicated by button tabs  807  and  808  and needle guide opening  803 . The needle channel  803  is closed by sleeve lock  823  and retained in a closed position by flexible retaining tab  812 , the sleeve lock  823  having finger grips as seen and a groove (not visible) which holds the halves of the needle guide  803  together. Also shown are a disposable plastic sheath  809  and flexible locking tab  801  for locking together with a sensor and cable assembly seen in  FIG.  10   . Circle D will be described in  FIG.  8 F . 
       FIG.  8 F  provides an expanded view (Detail D) of the sleeve lock  823  showing needle guide halves  821 ,  822  held together in a groove  824  facilitated by quarter-circular section  825 A (or other arcs of a circle may be used or a straight cut of the groove  824  and needle guide halves such as at a forty-five degree angle. 
       FIG.  8 G  shows a rear perspective view of the needle guide and sensor housing with flexible locking tab  801 , needle guide  803 , button tabs  807 ,  808 , sensor housing  803 , quarter-circular section  825 A of a gripping groove of sleeve lock  823  held in closed position by flexible retaining tab  812  and disposable plastic sheath  809 . Circle C will be described with reference to  FIG.  8 H . 
       FIG.  8 H  provides a rear expanded perspective view of the closure of needle guide  803  (Detail C) having flexible halves  821  and  822  within a groove  824  of sleeve lock  823  showing a quarter-circular section  825 A for matching with a needle guide quarter-circular section  825  along closure line  820 . As explained above, other arcuate cuts of groove  824  may match with arcuate cuts of needle guide halves or a line cut at an angle of approximately forty-five degrees may be applied to close normally open halves  821  and  822   
       FIG.  8 I  provides a cross-section of the disposable plastic sheath portion including sheath  809 , the needle channel distal tip  804  and the sensor channel tip  805  which may comprise a window for an internal ultrasound transducer assembly (not shown). 
       FIGS.  9 A through  9 I  provide views of a combination assembly of the sensor housing and needle guide section (distal or patient end) with the sensor and cabling section (proximal end) using the groove needle guide locking mechanism or sleeve lock  923  as discussed above. Referring to  FIGS.  9 E and  9 I , for example, an imaging plane of a transducer array is aligned with a needle/syringe delivery port so that the imaging plane captures images of the tool as it emerges into the imaging plane and a surgeon need not optimize the delivery of the tool to be seen by reflected ultrasound. 
       FIG.  9 A  provides a top view of the combination assembly comprising from left to right sensor channel tip  905  with a needle guide tip directly above but not easily discernable. Sensor channel or probe housing  902  holds, for example, a probe comprising a linear phased array with each element connected to leads of a cable (not seen) until the cable exits at right as cable  906 A. Flexible needle guide  903  in flexible halves is shown closed within a groove of circle B. Gripping tab or sleeve lock  923  that may slide back is shown closed and retained by retaining tab  912  so that a groove closes needle guide  903  having flexible halves that close together around a needle, syringe or other tool. Next to the right is disposable sheath  909  and a cable joining section  906 B of a probe, probe housing and cable assembly locked together as will be discussed with reference to  FIG.  9 B . 
       FIG.  9 B  is a cross-section along line A-A of  FIG.  9 A  so as to see the internal components of the combination assembly. A right-side cross-section of the assembly comprises from right, cable  906 A which merges with cable joining section  906 B and the individual piezoelectric element leads pass through sections  906 B and  906 C (a probe section) to, for example, a linear phased array of elements facing forward at sensor tip  905 . A flexible locking tab  901  locks needle guide section  902 ,  903 ,  904 ,  907 ,  908 , along with cable section disposable housing  909  to the internal cable and sensor sections  906 A,  906 B and  906 C. 
       FIG.  9 C  is a further exploded top view (Detail B) of the needle guide locking mechanism comprising along closing line  920  a first quarter-circular groove section  925 A and an opposite quarter-circular grove section  925 B of groove  924  of sleeve lock  923  which close around needle guide halves  921  and  922  to close the needle guide  903 . As already discussed, a quarter-circle cut is one of many cuts of the groove  924  and of the halves of the normally open flexible needle guide  903 . 
       FIG.  9 D  is a complete assembly side view comprising from left to right a sensor tip  905 , a sensor probe housing  902 , needle guide button tabs  907  and  908  and needle guide  903 . The sleeve lock  923  is seen in a closed position so that normally open flexible needle guide  903  would be closed. Disposable plastic sheath  909  is seen next with flexible locking tab  901  holding sensor and cable assembly  906 A and  906 B in place, mostly internally within the housings/sheaths  902  and  909 . 
       FIG.  9 E  provides a front perspective view of the entire assembly. Starting from left is seen the sensor housing tip  905 , the probe housing  902 , needle guide button tabs  907 ,  908 , the flexible, normally open needle channel  903  with sleeve lock  923  having quarter-circular section  925 A for locking the needle guide  903  in a groove of sleeve lock  923  in a closed position (Circle D discussed in  FIG.  9 F ) held by flexible retaining tab  912 , disposable plastic sheath section  909  (covering cable, not visible and, for example, containing an accelerometer and/or at least one gyroscope for alignment of images with gravity) and ultrasound sensor and cable sections  906 B and cable  906 A may be seen. When sleeve lock  923  is moved to the rear opening the normally open needle channel  903  via the sleeve lock  923 , the sleeve lock  923  is retained by a flexible retaining tab on the bottom of sheath  909 . A forward-directed linear phased array may be located just behind sensor tip  905  as will be discussed later herein. An approximately two-dimensional ultrasound imaging plane  919  is shown to be oriented perpendicular to the face of the ultrasound array to the center of the needle port delivery port portion of the sheath; (see also  FIG.  9 I ). This ensures that during a procedure the needle or other tool emerging from the needle guide  903  at its distal port is automatically visible in the ultrasound image without the physician needing to adjust the relative orientation of a sheath or ultrasound probe. 
       FIG.  9 F  provides a front perspective view of the needle guide locking mechanism in a closed position along line  920  (Detail D). Sleeve lock  923  locks normally open, flexible needle guide halves  921  and  922  together in a groove  924  having a quarter-circular section  925 A and a rear groove face  926 A and is retained in closed position by flexible retaining tab  912  ( FIG.  9 E ). As already discussed, other arcuate cuts of the groove  924  and halves  921 ,  922  will also close the needle guide channel as will an approximately forty-five degree angle cut. 
       FIG.  9 G  provides a rear perspective view of the combination assembly from left to right comprising the sensor housing tip  905 , the probe housing  902 , needle guide button tabs  907 ,  908 , the normally open needle channel  903  with sleeve lock  923  having quarter-circular section  925 A for locking the needle guide  903  (in circle C) in a groove of sleeve lock  923 , disposable plastic sheath section  909  (covering cable) and ultrasound sensor and cable sections  906 B and cable  906 A may be seen along with flexible locking tab  901  for holding the outer housing together with the probe and cable assembly inner housing. A forward-directed linear phased array may be located just behind sensor tip  905  as will be discussed herein. 
       FIG.  9 H  is an exploded view of Detail C where needle guide halves  921 ,  922  of needle guide  903  are held together by a groove  924  of sleeve lock  923 . 
       FIG.  9 I  is very similar to  FIG.  8 I  and shows a cross-section of the disposable plastic sheath portion  909 , the needle channel tip and the sensor channel tip  905 , the needle channel tip being the end portion of the needle guide  903 . The exact orientation of the ultrasound image plane  919  is shown to intersect the center of the imaging array and needle delivery port, thereby ensuring that the needle or other tool being delivered will be visible in a processed ultrasound image (not shown) without the physician having to adjust the relative position of the sheath or ultrasound probe. 
       FIGS.  10 A through  10 I  depict several views of the above-described needle guide embodiment and probe and cable assembly also including an exemplary needle having a handle  1010  and a tip  1011 . The needle  1011  and handle  1010  are shown in the needle channel  1003  having flexible halves. The needle  1010 ,  1011  may be a biopsy needle and be hollow for collecting tissue at a site of interest or a syringe for removing fluids (for example, during a cardiocentesis) located by forward-imaging of a transducer array located behind sensor tip  1005 . Flexible retainer tab  1012  retains sleeve lock  1023  in a closed position and normally open needle guide  1003  is locked closed. 
       FIG.  10 A  shows section A-A seen in  FIG.  10 B .  FIG.  10 A  from left to right includes but is not limited to showing needle tip  1011 , closed but normally open needle guide  1003 , sleeve lock  1023 , needle handle  1010 , circle B for explaining the locking mechanism, disposable plastic sheath section  1009 ; letter A where the locking tab  1001  would be located on the underside and is not visible, locking the entire assembly including cable narrowing section  1006 B and cable section  1006 A. Needle handle  1010  may comprise a syringe. 
       FIG.  10 B  shows section A-A comprising from left to right a needle tip  1011 , button tabs  1007  and  1008  which assist in lifting needle  1011  out of the needle channel  1003 , sensor tip  1005 , probe and cable housing  1006 C, piezoelectric element leads  1002 , needle handle  1010 , flexible locking tab  1001  in the vicinity of A of  FIG.  10 A , cable narrowing section  1006 B and cable section  1006 A. 
       FIG.  10 C  provides an expanded view of detail B (circle B of  FIG.  10 A ) showing the normally open, flexible needle channel halves  1021 ,  1022  in a locked and closed position in groove  1024  having been guided into groove  1024  by quarter-circular edges  1025 A,  1025 B of the distal end of groove  1024  (also other arcs or linear cuts may be used).  FIG.  10 C  also shows needle handle  1010  and a top viewable portion of sleeve lock  1023 . 
       FIG.  10 D  is a side view of a complete assembly including both a probe and cable housing portion  1005 ,  1002 ,  1009 , a locking sleeve  1023  held in a closed position by retaining tab  1012 , a needle  1011  and handle  1010  held in needle channel  1003  by button tabs  1007 ,  1008  and a disposable sheath  1009  having a flexible retaining tab  1001  for securing (or releasing) a cable and probe section  1006 A,  1006 B,  1006 C. Retaining tab  1013  stops sleeve lock  1023  from moving rearwards along sheath  1009  but is used during assembly as will be described herein for installing sleeve lock  1023 . 
       FIG.  10 E  provides a front perspective view of a complete assembly as seen in  FIG.  10 D  comprising four components, a needle  1011  and needle handle  1010 , the needle residing in a needle channel  1003  of a needle guide, the needle  1011  supported by button tabs  1007  and  1008  of the needle guide portion of a probe and cable housing comprising the needle guide, a distal probe tip window  1005 , a probe housing  1002  and a disposable sheath  1009  having a flexible locking tab  1001  for locking, for example, a probe containing a linear phased transducer array located behind the window  1005 , and element leads to a cable exiting the sheath  1009  via cable narrowing section  1006 B while cable  1006 A leads to a processor and display (not shown) and the sleeve lock  1023  which is slid down sheath  1009  and over retaining tab  1012  to close needle channel  1003  over needle  1011 . Circle D will be discussed with reference to  FIG.  10 F . 
       FIG.  10 F  provides an expanded view of detail D (circle D of  FIG.  10 E ) showing the normally open, flexible needle channel halves  1021 ,  1022  in a locked position in groove  1024  having been guided into groove  1024  by quarter-circular edges  1025 A,  1025 B (not visible) of the distal end of groove  1024  joining the two halves  1021 ,  1022  of needle channel  1003 . (A discussion of alternative edges will not be discussed again.)  FIG.  10 F  also shows needle handle  1010  and a top viewable portion of locking sleeve  1023 . 
       FIG.  10 G  provides a rear perspective view of a complete assembly as seen in  FIG.  10 D  comprising four components, a needle  1011  and needle handle  1010 ; the needle  1011  residing in a needle channel  1003  of a needle guide, the needle  1011  supported by button tabs  1007  and  1008  of the needle guide portion of a probe and cable housing comprising the needle guide, a distal probe tip window  1005 , a probe housing  1002  and a disposable sheath  1009  having a flexible locking tab  1001  for locking, for example, a probe containing a linear phased transducer array (not shown) located behind the window  1005 , and element leads to a cable exiting the sheath  1009  via cable narrowing section  1006 B while cable  1006 A leads to a processor and display (not shown) and the sleeve lock  1023  which is slid down sheath  1009  during assembly and over retaining tab  1012  to close needle channel  1003  over needle  1011 . As already discussed, an accelerometer and/or at least one gyroscope may be located in sheath  1009  for maintaining an image on a display (not shown) in alignment with the gravitational field of the earth. Circle C will be discussed with reference to  FIG.  10 H . 
       FIG.  10 H  provides an expanded view of detail C (circle C of  FIG.  10 G ) showing the normally open needle channel halves  1021 ,  1022  in a locked, closed position in groove  1024  having been guided into groove  1024  by quarter-circular edges  1025 A,  1025 B (not visible) of the distal end of groove  1024  joining the two halves  1021 ,  1022  of needle channel  1003  to form a closed needle channel.  FIG.  10 H  also shows needle handle  1010  and a top viewable portion of locking sleeve  1023 . 
       FIG.  10 I  is very similar to  FIGS.  8 I and  9 I  but differs in showing needle tip  1011  emerging from needle guide  1003  and shows a cross-section of the disposable sheath portion  1009 , the needle channel tip  1004  and the sensor channel tip  1005  with the end portion of the needle guide  1003 . 
       FIG.  11 A  provides a top view of a complete assembly of an image guided catheter or probe  1100  as seen also in  FIG.  10 E  with sleeve lock  1123  open comprising four components, a needle  1111  and needle handle  1110 , the needle still residing in a needle channel  1103  of a needle guide, the needle  1111  supported by button tabs (not visible) of the needle guide portion of a probe and cable housing comprising the needle guide, a distal probe tip window  1105 , a probe housing  1102  and a disposable sheath  1109  having a flexible locking tab (not visible) for locking, for example, a probe containing a linear phased transducer array located behind the window  1105 , and element leads to a cable exiting the sheath  1109  via cable narrowing section  1106 B while cable  1106 A leads to a processor and display (not shown) and the sleeve lock  1123  which is slid down sheath  1109  and over retaining tab (not visible) to close needle channel  1103  over needle  1111  via groove  1124 . Circle B will be discussed with reference to  FIG.  11 C . Cross-section A-A will be discussed with reference to  FIG.  11 B . 
       FIG.  11 B  provides a cross-section view of a complete assembly along A-A of  FIG.  11 A  and comprises four components, a needle  1111  and needle handle  1110 , the needle  1111  residing in a needle channel  1103  of a needle guide, the needle  1111  supported by button tabs  1107 ,  1108  of the needle guide portion of a probe and cable housing comprising the needle guide located at the top, a distal probe tip window  1105 , a probe housing  1102  and a disposable sheath  1109  having a flexible locking tab  1101  for locking, for example, a probe containing a linear phased transducer array located behind the window  1105  seen as section  1106 C, and element leads (not shown) to a cable section  1106 A exiting the sheath  1109  via cable narrowing section  1106 B while cable  1106 A leads to a processor and display (not shown) and the sleeve lock  1123  which is slid down sheath  1109  and over retaining tab  1113  to close needle channel  1103  over needle  1111  via groove  1124 . The needle channel  1103  is normally open and sheath  1123  has not been moved toward the distal tip  1105  to close the normally open needle channel  1103 . 
       FIG.  11 C  provides an expanded view of Detail B of  FIG.  11 A  showing the needle channel open and comprises the flexible needle channel halves  1121 ,  1122  in a normally open, unlocked position outside groove  1124  having been released from groove  1124  and quarter-circular edges  1125 A,  1125 B of the distal end of groove  1124  releasing the normally open two halves  1121 ,  1122  of needle channel  1003  to their open state to expose to view needle  1110  with its handle  1111  also visible.  FIG.  11 C  also shows needle handle  1111  and a top viewable portion of locking sleeve  1123 . 
       FIG.  11 D  provides a side view of the complete assembly of four parts with the needle channel  1103  open but the needle  1111  and needle handle  1110  still residing in the open needle channel  1103 . Locking sheath  1123  has been moved toward the proximal end to be stopped by retaining tab  1113 . From left to right, imaging window  1105  of probe housing  1102  has mounted thereon a needle guide comprising button tabs  1107 ,  1108  supporting needle  1111  in open needle channel  1103 . At the end of needle channel  1103  is seen a quarter-circular edge of the channel which mates with quarter-circular edge  1125 A of groove of open sheath/sleeve  1123  when closed but, when open, sleeve lock  1123  rests against retaining tab  1113  and surrounds sheath  1109 . Locking tab  1101  locks in probe and cable assembly comprising a cable narrowing section  1106 B leading to cable  1106 A. 
       FIG.  11 E  is a front perspective view of a complete assembly with the needle channel  1103  open and the needle  1111  and needle handle  1110  are exposed and are supported on button tabs  1107  and  1108  of the normally open needle guide. From left, the probe housing tip or window  1105  is seen on probe housing  1102  while sleeve lock  1123  is shown open (moved proximally) on disposable sheath  1109 . Flexible locking tab  1101  locks probe and cable section within comprising visible cable narrowing section  1106 B and cable  1106 A. Circle D will be described with reference to  FIG.  11 F . Needle handle  1110  may comprise a syringe having two cylindrical sections. 
       FIG.  11 F  is an expanded view of detail D of  FIG.  11 E  showing the normally open needle channel halves  1121 ,  1122  open exposing to view needle  1111  and needle handle  1110  and comprises the needle channel halves  1121 ,  1122  in an open, unlocked position outside groove  1124  having been released from groove  1124  and quarter-circular edges  1125 A,  1125 B of the distal end of groove  1124  releasing the two halves  1121 ,  1122  of needle channel  1103  to expose to view needle  1111  with its handle  1110  (which may comprise a syringe) also visible.  FIG.  11 F  also shows needle handle  1110  and a top viewable portion of locking sleeve  1123 . 
       FIG.  11 G  is a rear perspective view of the complete assembly with the normally open, flexible needle channel  1103  open and the needle  1111  and needle handle  1110  are exposed and are supported on button tabs  1107  and  1108  of the open needle guide. From left, the probe housing tip or window  1105  is seen on probe housing  1102  while sleeve lock  1123  is shown open (slid proximally) on disposable sheath  1109 . Flexible locking tab  1101  locks probe and cable section within, the section comprising visible cable narrowing section  1106 B and cable  1106 A. Circle C will be described with reference to  FIG.  11 H . Needle handle  1110  may comprise a syringe having two cylindrical sections, one for holding fluid and a pull handle for withdrawn fluid through a hollow needle  1111 . 
       FIG.  11 H  is an expanded view of detail C of  FIG.  11 G  showing the needle channel halves  1121 ,  1122  open exposing to view needle  1111  and needle handle  1110  and comprises the normally open, flexible needle channel halves  1121 ,  1122  in an open, unlocked position outside groove  1124  having been having been released from groove  1124  and quarter-circular edges  1125 A,  1125 B of the distal end of groove  1124  releasing the normally open two halves  1121 ,  1122  of needle channel  1103  to expose to view needle  1111  with its handle  1110  (which may comprise a syringe) also visible.  FIG.  11 H  also shows needle handle  1110  and a top viewable portion of locking sleeve  1123 . 
       FIG.  11 I  is a top perspective expanded cross-sectional view showing open needle channel  1103  comprising normally open needle channel halves  1121  and  1122  in an open position. Needle  1111  has handle  1110  shown still inside the open needle channel  1103  comprising halves  1121  and  1122  also open.  FIG.  11 I  further shows cross-section  1109  of disposable sheath  1109  and the probe window or distal probe housing end  1105 . 
       FIGS.  12 A through  12 I  are identical to  FIGS.  11 A through  11 I  but for the movement of needle  1211  and handle  1210  vertically out of the needle channel  1203  and will not be described in any detail to avoid redundancy. However,  FIG.  12 I  will be briefly explained as it shows the needle  1111  and handle  1110  removed from the open needle channel vertically. 
       FIG.  12 I  shows needle handle  1210  and needle  1211  removed vertically and outside the open needle channel comprising open needle channel halves  1221  and  1222 . Probe distal end  1205  is seen as is the sheath section  1209  in cross-section. 
       FIGS.  13  through  17 B  provide an overview of the insertable probe, cable and linear phased array transducer assembly  1006 A,  1006 B,  1106 C, that is locked by a flexible locking tabs  101 ,  201 ,  501 ,  801 ,  901 ,  1001 , for example, inside disposable sheaths  102 ,  202 ,  502 ,  909 ,  1009 , for example. 
       FIG.  13    provides a side view at its center of a plurality ultrasonic elements (not visible) of a transducer probe according to the present invention which may have a protective sheath (for example, sheath or probe housing  702  of  FIG.  7   ) disposed between the probe  1361  located toward the distal tip  1360 . All distances if any are shown are approximate and may be changed for different applications such as reaching the heart pericardial sac (also known as the pericardial space) versus reaching a melanoma close to the skin or a kidney with an anterior approach with optimized resolution and are shown in millimeters. A convention used in the brief and detailed description is that a reference numeral YXX may be used wherein the Y provides the Figure number where an element first appears and the XX (which may be any two-digit number) may represent the reference numeral of the element (used consistently for a similar component), for example, transducer array  1362  comprises Y for  FIG.  13    and XX for numeral  62  which represents the transducer array while element  1310 A represents the cylindrical housing  1310 A shown in  FIG.  13    held within disposable sheath, for example,  1109  by a surgeon (not shown in this figure series). To the left of  FIG.  13   , is seen a cross-section of a plane of housing  1310 A including both the probe  1361  and the cylindrical housing  1310 A. At the right of  FIG.  13    is shown a cross-section  1340  intended to show the radially placed elements of the outer cylindrical housing  1310 A, cable transition portion  1206 B, the strain relief feature and the cable  1206 A including, for example, the twenty-three leads to the transducer linear phased array, shown by way of example, which in turn leads to a display processor and display. Views  1361 ,  1362 ,  1316  are shown enlarged as  FIGS.  14 A  (end view) and  14 B (cross-sectional top view) of exemplary linear phased array elements  1462 - 1  through  1462 - 23 . 
       FIG.  14 A  shows a first exemplary embodiment of a front view of an exemplary ultrasound linear phased array having, for example, twenty-three linear elements  1462 - 1  through  1462 - 23  of, for example, 0.1 millimeters pitch (approximately one lambda wavelength of the center frequency of fifteen megahertz) making a total array  1362 ,  1462  of about 2.3 millimeters by 2.3 millimeters for a center frequency of approximately fifteen megahertz. The center frequency for a probe linear phased array may be selected within a range of ten to forty megahertz, and each piezoelectric element may have a pitch of between 0.85 to 1.15 times the wavelength of the selected center frequency. A more conventional pitch or 0.5 to 0.6λ may also be used but will increase the number of cable leads to the array and may impact subcutaneous use due to need for a larger diameter probe. Not shown in  FIG.  14 A  or distal tip  1360  of  FIG.  13    is that the linear phased array may be protected within a dome, flat window, no window, or tapered window of the housing including the needle guide. On the other hand, a window at distal tip  105  of a probe housing per  FIG.  1 A , for example, may comprise a dome or window protecting the transducer array. A probe shaft cylindrical housing  1410 A ( FIG.  14 B ) is seen that may have a circular cross-sectional shape that is approximately four millimeters in diameter as seen in  FIG.  13   . Not shown, the probe shaft cylindrical housing  1410 A may contain electrical signal leads to the linear phased transducer array  1362  for transmitted and reflected ultrasound signals and an accelerometer and/or at least one gyroscope having leads which produce signals which when processed may be used to align any image on a display (not shown) with the gravitational field of the earth. One transducer array may be replaced with another transducer array having a different center frequency and similar one lambda or a conventional half lambda pitch (but more linear elements) and still fit within the outer probe housing diameter, for example, four millimeters. The array  1362  may comprise individual linear phased array transducer elements comprising a one by twenty-three linear array shown as elements individually numbered  1462 - 1  through  1462 - 23 . More elements would be needed for a conventional array of linear elements at one half lambda pitch. The white area between the linear phased transducer array  1362  and the housing  1361  is un-numbered and comprises a potting material  1464  seen best in top-down cut-away view  FIG.  14 B . As described above these array elements  1462 - 1  through  1462 - 23  for different center frequency may be contained within a probe insertable into a disposable outer housing,  FIGS.  1  through  12 I  so that transducer arrays may be exchanged for different applications of the probe. 
       FIG.  14 B  shows a top sectional  1460  comprising the distal tip and, in particular, comprises from left to right a cross-hatched probe shaft housing  1410 A, an array potting material  1464  to firmly grasp the linear phased array elements  1462 - 1  through  1462 - 23  ( FIG.  14 A ). Below the section  1460 , there is seen at the center of the probe shaft housing  1410 A, an aperture for conducting an electrical signal cable  1465 , narrowing the signal cable  1465  from the diameter of cable channels to piezoelectric elements  1462 , the leads carrying signals to/from the linear phased array elements  1462 - 1  through  1462 - 23  via the array backing  1463 . The aperture is preferably walled as shown and extends the entire length of the probe shaft housing, carrying the electrical cable  1465 . 
       FIG.  15 A  is a blow-up of the left side cross-section of  FIG.  13   . There is a section labeled  1316  intended to represent a thicker portion of the hollow cylindrical housing  1310 A of  FIG.  13   . A pair of broken lines, perpendicular to one another signifies the center of the cylindrical housing  1310 A. Similarly, a pair of solid lines perpendicular to one another signifies the center of the probe shaft housing in circle A such that the distance between the two centers may be approximately six millimeters and the diameter (shown as a single line and arrow tip) of the cylindrical housing  1310 A may be approximately 17.5 millimeters (within a range of, for example, twelve to twenty-five millimeters). 
       FIG.  15 B  is a blow-up of detail A of  FIG.  15 A  showing the relationship between the linear phased transducer array  1462 , its probe shaft  1461  which may comprise potting material  1464  and the outer wall  1416  of the cylindrical housing  1310 A. The partial circular line is intended to show that wall  1416  only represents a portion of cylindrical housing  1310 A and should not be considered a part of the image guided probe which may be reusable and removable from the outer sheaths depicted in Figures described above. 
       FIG.  16    provides either a top-down view or a bottom-up view of the image guided probe at the center of  FIG.  13    (without showing details of any sheath for protecting the probe so that the probe housing is reusable). The view shows the probe  1350 &#39;s distal end  1360  where would be located the linear phased transducer array  1462  of the present invention. The center section is the cylindrical housing  1310 A that is covered by a disposable sheath that may be grasped and utilized by a surgeon. The section transition feature  1315  provides a side view of an example transition between the probe&#39;s cylindrical cable housing  1310 A and the cable strain relief feature  1306 B which provides the exit of cable  1306 A from the imaging probe for image processing and display. 
       FIG.  17 A  is a left front perspective view of an image guided probe comprising distal probe end  1360 , probe shaft  1350 , cylindrical housing  1310 A, transition feature  1315 , flexible cable section  1306 B and cable  1306 A from left to right. 
       FIG.  17 B  is a right rear perspective view of an image guided probe showing the same components in the same order as is seen in  FIG.  17 A  from upper left to lower right. 
     Assembly of a device  1000  will now be described with reference to  FIGS.  10 A and  10 B  starting with section  1009 ,  1002 ,  1005 . The sleeve lock  1023  is introduced from the right (proximal end or surgeon end) by passing sleeve lock  1023  over sheath  1009  via flexible locking tab  1001 . The sleeve lock is moved toward the distal end and passes over flexible retaining tab  1013  where it is locked between an open and a closed (distal) position. With the sleeve lock proximate to tab  1013 , the normally open needle channel is open so that needle  1011  and handle  1010  may simply be lain vertically unto button tabs  1007  and  1008  within the channel. Then, the sleeve lock  1023  may be moved forward over flexible retaining tab  1012  to lock the needle channel and secure the needle  1011  within the normally open needle channel  1003 , now closed around the needle. The needle and handle may be moved forward and back. 
     The cable and probe section assembly  1006 A,  1006 B and  1006 C may then be slid in from the proximal (surgeon side) and locked in place by the flexible locking tab  1001 . The surgeon may adjust the needle  1011  and handle  1010  within the needle guide. The surgeon may start with a solid introducer needle to puncture skin tissue. A sheath may be slid over the solid introducer needle if its tip is at a medical procedure site via external or internal imaging. If subcutaneous entry of the probe is desired, the probe may follow the introducer needle into the skin tissue puncture made by the introducer needle. The introducer needle, depending on the procedure may be followed by replacing the introducer needle with a hollow biopsy needle or a syringe via the sheath. Any viewed needle, syringe or sheath may be rendered echogenic following the methods and procedures described in U.S. Provisional Application 62/526,170, filed Jun. 28, 2017. A pacer placement procedure for installing and securing a pacer through the heart pericardium is described in U.S. provisional patent application Ser. No. 62/527,865, filed Jun. 30, 2017, incorporated by reference as to its entire contents. This is one example of the use of an embodiment of the present device  1000 . In a similar manner, and without subcutaneous use of the probe housing  105  (only use of the needle of the needle guide), cardiocentesis may be performed by first creating a path with a needle  1011  via the needle guide to inside a pericardial space having excess fluid. The needle is covered with a sheath under ultrasound vision and a syringe is used and its needle inserted within the pericardial space for removal of excess fluid under vision. Further U.S. provisional patent application Ser. No. 62,527,905 filed Jun. 30, 2017, incorporated by reference as to its entire contents may be referred to for replacement of a heart valve using the present device  1000 . Similarly, a needle is used to place a sheath and an expanding umbrella and tools for defective heart valve removal or applied through the sheath under vision and a replacement heart valve inserted replacing the defective heart valve. Other procedures have and will be discussed herein using an embodiment of device  1000  using different components of different dimensions and different medical procedure capabilities. 
     In some embodiments, device  1000  (with or without an optional handle) can be steerable and externally controlled by the operator. In some embodiments, one or more Micro-Electro-Mechanical Systems (MEMS) devices can be incorporated into the use of the device  1000  to allow an operator to control aspects of the device. MEMS systems can include, for example, mechanical elements (beams, cantilevers, diaphragms, valves, plates, and switches), sensors, actuators, and electronics. Referring to FIG. 7A of U.S. patent application Ser. No. 13/847,902, (now U.S. Pat. No. 9,149,257), a MEMS position manipulator  701  can be mounted on device  100  at a distal portion of device  100  to control a position of transducer  210  to, for example, standard position  702 , Position A  702   a  or Position B  702   b . In other embodiments, one or more MEMS devices can be provided to function as tiny sensors and actuators. For example, MEMS can be incorporated in the device for measuring and monitoring pressure in the stomach or other organs in which the catheter is inserted, and for measuring and monitoring blood pressure when performing cardiac catheterization. According to the present invention, the tool may be provided with an echogenic surface to improve visibility (see U.S. provisional patent application Ser. No. 62/526,170 filed Jun. 28, 2017 for use of echogenicity) and a contrast agent used if appropriate for the procedure to improve ultrasound visibility of blood vessels. 
     In another embodiment, for example, as shown in FIG. 7B of U.S. patent application Ser. No. 13/847,902, (now U.S. Pat. No. 9,149,257) a MEMS manipulator lead fixation device  703  can be provided to permit an operator to remotely access a portion of a device within a patient&#39;s body. For example, MEMS manipulator  703  can be used to screw in a lead for a pacemaker implanted in a patient or directly mount a pacemaker to the pericardium without the use of electrical stimulation leads which are typically planted in the pericardium according to known procedures. Alternatively, MEMS manipulator  703  can be used to operate a biopsy needle, syringe, sheath or other tool or to manipulate a suture-application device within a patient. It should be noted that these uses are exemplary only and that a device  1000  capable of using a MEMS manipulator as described herein can be used to access or manipulate any device in a body or for any other suitable purpose. 
     In accordance with aspects described herein, a device  1000  may have a biopsy instrument such as, for example, the biopsy device depicted in FIGS. 8A-8D of U.S. patent application Ser. No. 13/847,902, (now U.S. Pat. No. 9,149,257). In such an embodiment, device  1000  can be adapted for use in biopsy procedures including but not limited to myocardial biopsy, brain biopsy (nasal cavity or ear canal entry to the brain is possible without probe entry), muscle biopsy, lung biopsy, liver biopsy, kidney biopsy, uterine and ovarian biopsy, esophageal biopsy, stomach biopsy, intestinal biopsy, tumor biopsy (anywhere), targeted biopsy of potentially abnormal zones in any of the above items (e.g., ultrasound or OCT guided biopsy of an abnormal area in the liver or kidney with the present catheter will allow access to the abnormal area, identification of abnormal zones by deploying the ultrasound and biopsy instrument to the specific area of interest). As such, device  1000  can, in some cases, be used in the form of a catheter or probe for delivery of a sheath-like device that is insertable through small incisions in the body. A biopsy tool could be inserted through the needle channel of the device  1000  as could a syringe needle. As used herein, device  1000  generally refers to any embodiment of an image catheter device or probe of the present invention, for example, with or without a handle, with a tapered or flat end, with a tab or a sleeve lock to close the needle channel around a tool, the device  1000  having, for example, an imaging channel  1003  and a needle/instrument channel mounted with the needle guide on top of the ultrasound probe or the probe mounted side by side or with the needle/instrument needle guide assembly being fixable to the device  1000  or removable and replaceably attached to the probe housing and with varying size or diameter of barrel or probe housing depending on the application. 
     In another embodiment, such as is shown in FIGS. 9A and 9B of U.S. patent application Ser. No. 13/847,902, (now U.S. Pat. No. 9,149,257), device  1000  can include a retrieval instrument in combination with a bioptome or another custom instrument. As is known in the art, a bioptome can comprise a specialized biopsy catheter/probe for use in cardiac applications, particularly a catheter/probe with a special end designed for obtaining endomyocardial biopsy samples. In use, a bioptome can be threaded through the needle lumen of the device  1000  to the right ventricle, where it can snip small tissue samples from the septal wall for pathologic examination. In other uses, a bioptome tip device can be used to monitor heart transplantation patients for early signs of tissue rejection. In use, as seen in FIGS. 9A and 9B of U.S. patent application Ser. No. 13/847,902, (now U.S. Pat. No. 9,149,257), a retrieval instrument having a bioptome  903  can be in closed position  901  at a distal end and closed position  904  at a proximal end to assist in inserting the instrument into the area of interest, and then can be placed into an open position  902  at the distal (patient) end so that the desired tissue can be retrieved for examination or testing. A tissue sample collected by either a retrieval instrument, a biopsy tool, or a bioptome may be removed for analysis either by threading the instrument out of the body through the needle or sheath lumen, or by removing the entire device from the patient&#39;s body along with the tissue sample. 
     Device  1000  in accordance with one or more aspects described herein can have many different embodiments for many different uses within the scope and spirit of the present disclosure. Device  1000  can be in the form of a catheter and a placed needle can carry a small diameter, minimally invasive sheath to a medical procedure site that provides entry into various body spaces, thus allowing therapy delivery, intervention, placement of devices and diagnostics. Device  1000  can also be in the form of interventional devices for use in procedures within these spaces. Such catheters, probes, sheaths, and devices are known, and, thus, the general features of device  1000  for these embodiments can be in accordance with conventional devices. 
     In addition, when provided with one or more integrated transducers (such as linear phased arrays) and other components required to provide ultrasound imaging as described herein, device  1000  can be used in a wide variety of procedures which can be made substantially safer and easier through the combination of ultrasound imaging aspects with therapeutic aspects of the ultrasound probe of device  1000 . 
     In some embodiments, device  1000  can be used to provide access to vascular structures including arteries, veins, lymphatics, and to other hollow structures or body orifices such as the gastrointestinal tract, genitourinary tract, and the respiratory system. As such, the device  1000  can be used with, for example, a vascular sheath (not shown, but shown in priority applications and patents). Such sheaths are well known, and, thus, the general features of device  1000  for these embodiments can be in accordance with conventional devices. 
     In other embodiments, device  1000  can be used in procedures in various body spaces such as the pleural peritoneal space, pericardial space, perisphinal space, pelvis, and cerebrospinal space. For example, the device can be adapted for use in paracentesis, biopsy of any intraabdominal or intrapelvic organ, prostate biopsy, biopsy of tumors or otherwise suspected abnormal structures within the pelvis and abdomen, diagnosis of endometriosis, treatment by chemicals, cells, bio-agents, physical energy (e.g., cryo, radiofrequency, heat, laser) of any pathology within the pelvis and abdomen, visualization and application of therapy within the genitourinary tract, and drainage of abnormal or normal collection of fluid in actual or potential space in the abdomen, pelvis or genitourinary tract. In other embodiments, device  1000  can be in the form of a catheter/probe which can be used with a syringe to drain fluid from a patient&#39;s gall bladder or any other hollow or solid organ in the abdomen. 
     Other procedures that can be performed using device  1000  include procedures relating to diagnosis and treatment of infertility, including following a woman&#39;s ovum to determine an appropriate time for harvest, harvesting the ovum, and assisting in or performing the delivery of the fertilized egg to the uterus (with or without use of a contrast agent or echogenicity). 
     In some embodiments, device  1000  can be designed for use in cardiac or vascular procedures and for accessing various targets. For example, device  1000  can be designed to provide access to various structures such as the coronary sinus and other cardiac venous structures. Exemplary procedures that can be performed using device  1000  can include: epicardial biopsy; electronic mapping (endocardial or epicardial); electromechanical mapping (endocardial or epicardial); endocardial or epicardial ablation using any form of energy; cannulation or delivery of catheters, heart rhythm pacing leads or pacemaker devices, and other interventional devices (medicinal pumps for calming tremors in Parkinson&#39;s disease patients; and mapping and access to the fossa ovalis and patent foramen ovale to enable crossing the atrial septum and allowing transvenous access to the left side of the heart; pericardiocentesis; left ventricular lead placement; delivery of therapy (e.g., drugs, stem cells, laser therapy, or ultrasound energy); epicardial coronary artery bypass; valve repair and placement, delivery of cardiac shape modifying devices (e.g., ACORN® or MYOSPLINT® devices); myocardial scar reconstruction; ventricular reconstruction; ventricular assist device placement; and the treatment by chemicals, cells, bio-agents, physical energy (e.g., cryo, radiofrequency, heat, laser) of any pathology within the pericardial space or myocardium or intracardiac. As such, device  1000  can, in some cases, be used with a sheath-like device introduced via an image-guided needle that is insertable through, for example, a needle puncture in the patient&#39;s upper thigh and through a blood vessel all the way up to the heart. In such embodiments, guidewire can be used with the device  1000  to guide the device  1000  to the target area for guidewire introduction through the vein. In other embodiments, the device  1000  can be inserted through the pericardial space through the use of an introducer needle or sheath integrated therein. 
     In other embodiments, device  1000  can be in the form of a device that is used in performing a cardiac procedure such as a biopsy instrument or an instrument for heart valve repair or replacement. In this case, device  1000  can be provided with one or more transducer imaging systems or used with auxiliary imaging systems such as OCT, along with the other components required to provide ultrasound imaging using the transducers as discussed herein and tools to implement the repair or replacement, for example, of a heart valve with or without contrast or using echogenicity (for the tool or use of the contrast agent in proximate heart tissue). 
     In other embodiments, device  1000  can be in the form of devices for use in performing procedures on the musculo-skeletal system and for accessing the musculoskeletal system. For example, device  1000  can be used for treatment by chemicals, cells, bio-agents, or physical energy (cryo, radiofrequency, heat, laser) of any pathology within the joint cavity, joint components, or muscle and bone; visualization and application of therapy involving muscle, bone, and joint components, including a joint cavity; and drainage of abnormal or normal collection of fluid in actual or potential space in the muscle, bone, or joint components. In these embodiments, device  1000  can be in the form of a catheter or sheath that provides access to the musculo-skeletal system, thus allowing therapy delivery, intervention, placement of devices and diagnostics. Device  1000  can also be in the form of interventional devices for use in procedures on the musculo-skeletal system. Such catheters, sheaths, and devices are well known, and, thus, the general features of device  1000  for these embodiments can be in accordance with conventional devices. Device  1000  would further include one or more transducer assemblies such as linear phased arrays, along with the other components required to provide ultrasound imaging using the transducer assemblies as discussed herein. 
     In some embodiments, device  1000  can be in the form of devices for use in procedures on the brain and nervous system and for accessing the brain and nervous system. For example, such devices can be used for the treatment by chemicals, cells, bioagents, or physical energy (cryo, radiofrequency, heat, laser) of any pathology within the cranium and spinal and pen-spinal space including the vasculature contained within; visualization and application of therapy within the cranium, spinal, and pen-spinal space and all contained vasculature; drainage of abnormal or normal collection of fluid in actual or potential space in the cranium, spinal, and pen-spinal space and all contained vasculature; and for transcatheter delivery of interventional devices such as aneurysm clips, hematologic treatments, and any other drug or non drug therapy, either directly or via the vasculature or via any other hollow structure within the cranium, spinal, and peri-spinal space and all contained vasculature. In these embodiments, device  1000  can be in the form of a catheter or sheath that provides access to the brain and system, thus allowing therapy delivery, intervention, placement of devices and diagnostics. Ultrasound visualization need not be subcutaneous but external or via a body orifice such as the nasal passages and ear canal. 
     Device  1000  can further be adapted for use in procedures on the nasal passages, sinuses, ear canals and pharynx and other orifices and for accessing these orifices to reach organs such as the brain and the throat and such as via the esophagus for accessing the heart. In these embodiments, device  1000  can be in the form of a catheter and use a sheath that provides access to a desired site of the nasal passages, sinuses, pharynx and heart, thus allowing therapy delivery, intervention, placement/replacement of devices and defective heart valves and diagnostics. Device  1000  can also be in the form of interventional devices for use in procedures on the nasal passages, sinuses, and pharynx (e.g., devices for therapy delivery, intervention, placement of devices and diagnostics). Such catheters, sheaths, and devices are well known, and, thus, the general features of device  1000  for these embodiments can be in accordance with conventional devices. Device  1000  would further include one or more transducers, along with the other components required to provide ultrasound imaging using the transducers as discussed herein. Device  1000  can further be in the form of devices used to treat and address chronic problems and, as such, can be delivered and lodged in body cavities, organs, or other anatomic locations for long term monitoring or anatomy or function or dynamics including hemodynamics. In these examples, the device  1000  can be in the form of a catheter or probe and introduce a sheath or other conventional chronic treatment or monitoring device that can be lodged at a desired site. Device  1000  may further include one or more transducer probes, along with the other components required to provide ultrasound imaging using the transducer assemblies as discussed herein. Device  1000  can also be used for implanting a monitoring or drug delivery device at a specific site in the body using its imaging capabilities to assist the user in finding a precise target site. In some embodiments, the present device  1000  can further be integrated with other non-ultrasound imaging modalities including infrared, laser, CT scan, X-ray, optical coherence tomography, fiber optic instruments including, but not limited to endoscopic mapping. For example, the imaging lumen or probe can further be provided with a fiber optic lumen through which an optical fiber is insertable in place or proximate to the linear phased array. 
     The devices  1000  can be used to perform any variety of medical procedures including those set forth herein. The general features of these procedures are in accordance with conventional procedures and further make use of the integrated imaging system to provide visualization while accessing and performing procedures at the target site. Access to other organs, structures, and spaces can be performed in similar fashion with appropriate procedural modifications specific for the particular organs, structures or spaces. 
     All documents mentioned herein are incorporated by reference herein as to any description which may be deemed essential to an understanding of illustrated and discussed aspects and embodiments of devices and methods herein. 
     Although the devices and methods discussed above and primarily illustrated and described herein provide instruments that also can be adapted for performing minimally invasive diagnostic or therapeutic procedures on humans, it will be appreciated by those skilled in the art that such instruments and methods also are adaptable for use in other surgical procedures as well as in performing various veterinary surgeries. Further, while several preferred embodiments have been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.