Patent Publication Number: US-2019192789-A1

Title: Pericardial access device and its methods of use

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 14/149,332 which was filed on Jan. 7, 2014, and is now U.S. Pat. No. 10,220,162, which is incorporated herein by this reference. 
    
    
     BACKGROUND 
     The subject matter described herein relates generally to medical devices and, more particularly, to a pericardial access device configured to access a pericardial cavity or space. 
     Medical devices are known to access a pericardial space for diagnostic and/or therapeutic purposes. The pericardial space is at least partially defined by a pericardium. The pericardium is a double-walled sac that substantially covers the heart. Due to the proximity of the pericardial space to the heart, percutaneously accessing the pericardial space through the pericardium may increase a risk of heart perforation, which may endanger and/or traumatize a patient. 
     BRIEF DESCRIPTION 
     In one aspect, a method is provided for using a pericardial access device to access a pericardial space. The access device includes a first tube, a second tube coupled to the first tube such that the pericardial access device is moveable between an expanded configuration and a contracted configuration, and a biasing mechanism that biases the pericardial access device towards the expanded configuration. The method includes positioning a distal end of the second tube adjacent a surface, advancing the pericardial access device to contact the surface, such that a force is applied to the second tube and the pericardial access device moves towards the contracted configuration, and advancing the pericardial access device towards the pericardial space while the pericardial access device is in the contracted configuration until at least the distal end of the second tube penetrates the surface. 
     In another aspect, a pericardial access device is provided for accessing a pericardial space. The pericardial access device includes a first tube, a second tube coupled to the first tube, and a biasing mechanism that biases the pericardial access device towards the expanded configuration. The pericardial access device is moveable between an expanded configuration and a contracted configuration. The pericardial access device moves towards the contracted configuration when a force is applied to the second tube. 
     The features, functions, and advantages described herein may be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments, further details of which may be seen with reference to the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic illustration of an exemplary pericardial access device in an expanded configuration; 
         FIG. 2  is a schematic illustration of the pericardial access device shown in  FIG. 1  in a contracted configuration; and 
         FIG. 3  is a flow chart illustrating an exemplary method of using the pericardial access device shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The methods and apparatus described herein relate to medical devices and, more particularly, to a pericardial access device configured to provide controlled access to a pericardial space. In some embodiments, the pericardial access device includes a first tube, a second tube coupled to the first tube such that the medical device is moveable between an expanded configuration and a contracted configuration, and a biasing mechanism that biases the pericardial access device towards the expanded configuration, and moves towards the contracted configuration when a force is applied to the second tube. The pericardial access device described herein provides access to the pericardial space in a controlled manner, such that a risk of heart perforation may be reduced. 
     As used herein, an element or step recited in the singular and preceded with the word “a” or “an” should be understood as not excluding plural said elements or steps, unless such exclusion is explicitly stated. Further, references to an “embodiment” are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising,” “including,” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property. 
       FIGS. 1 and 2  are schematic illustrations of an exemplary pericardial access device  100 . Pericardial access device  100  has an elongated body that is moveable between an expanded configuration (shown in  FIG. 1 ) and a contracted configuration (shown in  FIG. 2 ). For example, in the exemplary embodiment, pericardial access device  100  has a first length  102  when pericardial access device  100  is in the expanded configuration, and has a second length  104  less than first length  102  when pericardial access device  100  is in the contracted configuration. 
     Pericardial access device  100  includes a first tube  110 , and a second tube  120  coupled to first tube  110 . In the exemplary embodiment, first tube  110  is an outer sheath, and second tube  120  is an inner sheath at least partially positioned within the outer sheath, such that first tube  110  and second tube  120  are arranged in a telescopic configuration. Alternatively, first tube  110  and/or second tube  120  may be arranged in any configuration that enables pericardial access device  100  to function as described herein. 
     Pericardial access device  100  includes a biasing mechanism  130  positioned between at least a portion of first tube  110  and at least a portion of second tube  120 . In the exemplary embodiment, biasing mechanism  130  is coupled to first tube  110  and/or second tube  120 . In the exemplary embodiment, biasing mechanism  130  is in a relaxed state when pericardial access device  100  is in the expanded configuration, and is in a tensed state when pericardial access device  100  is in the contracted configuration. In the exemplary embodiment, pericardial access device  100  is biased towards the expanded configuration and moves away from the expanded configuration (i.e., increases or decreases in length relative to first length  102 ) when a force is applied to pericardial access device  100  or, more particularly, biasing mechanism  130 . A movement of first tube  110  relative to second tube  120  “charges” biasing mechanism  130  (e.g., moves biasing mechanism  130  away from the relaxed state and/or increases a spring force associated with biasing mechanism  130 ). 
     In the exemplary embodiment, biasing mechanism  130  is a spring positioned within first tube  110  and between a proximal end  132  of first tube  110  and a proximal end  134  of second tube  120 . In the exemplary embodiment, biasing mechanism  130  is coupled to proximal ends  132  and/or  134 , such that biasing mechanism  130  spans the distance between a distal surface of first tube proximal end  132  and a proximal surface of second tube proximal end  134 . In the exemplary embodiment, biasing mechanism  130  expands as pericardial access device  100  is moved towards the expanded configuration and/or as the distance between first and second tubes  110  and  120  increases, and contracts as pericardial access device  100  is moved towards the contracted configuration and/or as the distance between first and second tubes  110  and  120  decreases. For example, biasing mechanism  130  may be a cylinder, hydraulics, oil, and/or any other shock-absorber mechanism. Alternatively, biasing mechanism  130  may be any device and/or be coupled to any portion of pericardial access device  100  that enables pericardial access device  100  to function as described herein. 
     Pericardial access device  100  includes an indicating mechanism  140  configured to indicate whether pericardial access device  100  is in the contracted configuration and/or the expanded configuration. For example, in at least some embodiments, indicating mechanism  140  enables a user to visually, audibly, and/or tactilely monitor a relative positioning of first tube  110  and second tube  120  as pericardial access device  100  moves between the expanded configuration and the contracted configuration. For example, in one embodiment, indicating mechanism  140  includes a light source, a sound source, and/or a vibration source. In such an embodiment, indicating mechanism  140  may generate an alert when an electric circuit (as a switch) is closed or open. 
     In the exemplary embodiment, indicating mechanism  140  includes a first marker  142  extending about first tube  110  adjacent a distal end  144  of first tube  110 , and a second marker  146  extending about second tube  120  at a location  148  remote from distal end  144  of first tube  110  when pericardial access device  100  is in the expanded configuration, and adjacent distal end  144  of first tube  110  when pericardial access device  100  is in the contracted configuration. Alternatively, indicating mechanism  140  may be any device and/or be coupled to any portion of pericardial access device  100  that enables pericardial access device  100  to function as described herein. 
     In the exemplary embodiment, pericardial access device  100  includes a sensor (not shown) configured to detect a movement of first tube  110  and/or second tube  120  and/or a pressure at a distal end of pericardial access device  100 . In the exemplary embodiment, the sensor is configured to transmit a signal associated with the detection to indicating mechanism  140 . For example, in at least some embodiments, the sensor is an electric or piezoelectric sensor configured to detect a position and/or movement of first tube  110  and/or second tube  120 . Additionally or alternatively, the sensor is a pressure sensor configured to detect a pressure and/or a pressure change at the distal end of pericardial access device  100 . In at least some embodiments, pericardial access device  100  includes a single tube (i.e., a tube that is not arranged in a telescopic configuration with another tube) that includes and/or is coupled to a sensor at a distal tip of the single tube. 
     In the exemplary embodiment, indicating mechanism  140  generates a visual, audial, and/or tactile indication and/or alert associated with the detection based on the signal received from the sensor. Alternatively, the sensor may be any device and/or be coupled to any portion of pericardial access device  100  that enables pericardial access device  100  to function as described herein. In at least some embodiments, a position and/or movement of first tube  110  and/or second tube  120  may be automatically controlled based on the signal received from the sensor. 
     In at least some embodiments, pericardial access device  100  includes and/or is coupled to a computing system including a memory device (not shown) and a processor (not shown) coupled to the memory device. In such embodiments, the computing system enables indicating mechanism  140  and/or the sensor to function and/or communicate with each other. In such embodiments, the computing system is configurable to perform one or more operations described herein by programming the memory device and/or processor. 
     As used herein, the term “processor” is not limited to integrated circuits referred to in the computing arts, but rather broadly refers to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits. Moreover, the term “memory device” refers to a device that enables information such as executable instructions and/or other data to be selectively stored and retrieved. 
     In the exemplary embodiment, pericardial access device  100  includes a puncturing mechanism  160  configured to puncture a surface (e.g., a skin surface or a pericardium surface) and/or enable pericardial access device  100  to traverse through tissue. In the exemplary embodiment, puncturing mechanism  160  is a needle coupled to a distal end of second tube  120 . In at least some embodiments, the needle has a beveled tip and is hollow, such that a fluid and/or object may be channeled therethrough. Alternatively, a distal end  162  of second tube  120  is configured to puncture the surface. In one embodiment, puncturing mechanism  160  is sized and/or configured to enable a distal end of puncturing mechanism  160  to puncture a surface (e.g., a pericardium surface) while first tube  110  and/or second tube  120  are not subcutaneous (i.e., first tube  110  and second tube  120  stay outside of the body). Puncturing mechanism  160  may be any device, be coupled to any portion of pericardial access device  100 , and/or be a part of any portion of pericardial device  100  that enables pericardial access device  100  to function as described herein. 
     In the exemplary embodiment, first tube  110  and/or second tube  120  has an inner surface  170  that defines a lumen  180  configured to channel a fluid and/or an object there through. For example, in one embodiment, a guide wire is positioned within lumen  180  to facilitate guiding pericardial access device  100 . Additionally or alternatively, lumen  180  channels blood when second tube  120  and/or puncturing mechanism  160  punctures a heart, and the blood is channeled into pericardial access device  100  via a distal opening defined at a distal end of second tube  120  and/or puncturing mechanism  160 . In at least some embodiments, first tube  110  and/or second tube  120  is fabricated from a transparent material, such that the fluid and/or object being channeled through lumen  180  is visible to the naked eye through a sidewall of first tube  110  and/or second tube  120 . 
     In at least some embodiments, pericardial access device  100  includes a valve (not shown) that is configured to selectively provide access to lumen  180 . For example, in at least some embodiments, the valve is selectively moveable between an open configuration that provides access to lumen  180  and a closed configuration that restricts access to lumen  180 . 
     In at least some embodiments, pericardial access device  100  includes a plunging mechanism (not shown) that is at least partially positioned and moveable within lumen  180  to facilitate channeling the fluid and/or object through lumen  180 . For example, in one embodiment, a fluid and/or object is channeled through lumen  180  to facilitate radiologically and/or ultrasonically confirming a position of a distal end of second tube  120  and/or puncturing mechanism  160 . Additionally or alternatively, the distal tip of second tube  120  and/or puncturing mechanism  160  is radio opaque and/or detectable by ultrasound. Alternatively, lumen  180  may interface and/or interact with any device and/or mechanism that enables pericardial access device  100  to function as described herein. 
       FIG. 3  is a flow chart illustrating an exemplary method  300  of using pericardial access device  100  to access a pericardial space. During operation, distal end  162  of second tube  120  is positioned  310  adjacent a surface (e.g., a skin surface or a pericardium surface). In some embodiments, a user holds first tube  110  to position second tube  120  adjacent the surface. 
     Pericardial access device  100  or, more specifically, first tube  110  is advanced  320  towards the surface (e.g., an operator and/or an apparatus pushes first tube  110  towards the surface to increase a force associated with pericardial access device  100 ), such that a force is applied to distal end  162  of second tube  120 . 
     In the exemplary embodiment, when biasing mechanism  130  is not fully charged (i.e., biasing mechanism  130  is not in the contracted configuration) and the force applied to distal end  162  of second tube  120  is less than or equal to a predetermined threshold (i.e., a threshold associated with the surface), an increase in force associated with an advancement of first tube  110  is at least partially absorbed by biasing mechanism  130  and, thus, the advancement of first tube  110  moves pericardial access device  100  towards the contracted configuration. In at least some embodiments, advancement of first tube  110  moves first tube  110  relative to second tube  120  while second tube  120  remains substantially stationary relative to the surface. In at least some embodiments, a convergence of markers  142  and  146  and/or an increase in resistance indicates that pericardial access device  100  is approaching the contracted configuration. 
     In some embodiments, second tube  120  does not slide and/or move within first tube  110  when pericardial access device  100  is in the contracted configuration. In at least some embodiments, a proximal positioning of first marker  142  and second marker  146  (see  FIG. 2 ) indicates that pericardial access device  100  is in the contracted configuration. When biasing mechanism  130  is fully charged (i.e., biasing mechanism  130  is in the contracted configuration) and the force applied to distal end  162  of second tube  120  is less than or equal to the predetermined threshold, an increase in force associated with an advancement of first tube  110  cannot absorbed by biasing mechanism  130  and, thus, the advancement of first tube  110  directly increases the force applied to distal end  162  of second tube  120 . 
     When the force applied to distal end  162  of second tube  120  exceeds or is greater than the predetermined threshold, further advancement of first tube  110  moves second tube  120  relative to the surface (e.g., forces distal end  162  of second tube  120  to puncture the surface, e.g., the skin surface, and/or traverse the subcutaneous and/or muscle layer). In at least some embodiments, puncturing mechanism  160  facilitates puncturing the skin surface and/or traversing the subcutaneous and/or muscle layer. When second tube  120  and/or puncturing mechanism  160  punctures the surface, the force applied to distal end  162  of second tube  120  decreases, and pericardial access device  100  moves towards the expanded configuration. 
     Pericardial access device  100  is advanced  330  towards a pericardial space while pericardial access device  100  is in the contracted configuration until at least distal end  162  of second tube  120  penetrates a surface (e.g., a pericardium surface). In some embodiments, when distal end  162  of second tube  120  clears the surface, pericardial access device  100  returns and/or moves towards the expanded configuration. In at least some embodiments, a divergence of markers  142  and  146  and/or a decrease in resistance indicates that pericardial access device  100  is returning to the expanded configuration. 
     Additionally or alternatively, in at least some embodiments, indicating mechanism  140  indicates that distal end  144  of first tube  110  and/or distal end  162  of second tube  120  is in the pericardial space. In some embodiments, fluid and/or an object is injected to the pericardial space through lumen  180  to facilitate radiologically and/or ultrasonically confirming a position of first tube distal end  144  and/or second tube distal end  162 . 
     The embodiments described herein relate generally to medical devices and, more particularly, to methods and systems for providing controlled access to a pericardial space. The embodiments described herein enable a user to percutaneously access a pericardial space in a controlled manner. For example, the embodiments described herein enable a user to monitor a relative positioning of a first tube and a second tube as a pressure or force is applied to the second tube. 
     Exemplary embodiments of methods and systems for providing controlled access to a pericardial space are described above in detail. The methods and systems are not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the method may be utilized independently and separately from other components and/or steps described herein. Each method step and each component may also be used in combination with other method steps and/or components. Although specific features of various embodiments may be shown in some drawings and not in others, this is for convenience only. Any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing. 
     This written description uses examples to disclose the embodiments, including the best mode, and also to enable any person skilled in the art to practice the embodiments, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.