Overmold for a modular implantable medical device

Abstract

A modular implantable medical device permits implantable medical devices to have a smaller profile in order to better fit into locations within the human body. A modular implantable medical device separates various functional components of the implantable medical device into a set of interconnected modules. This distributed architecture of a modular implantable medical device may permit the device footprint to be distributed over a larger area while making the profile smaller, and may permit the overall shape of the implantable medical device to better match the body location into which it is to be implanted. An overmold integrates the modules of a modular implantable medical device into a single structure. In some embodiments the overmold is flexible and provides a biocompatible interface from the component modules and the patient, while restraining potentially harmful intermodule motion.

1 . An implantable medical device comprising: 
 a control module comprising a housing; and    an overmold that at least partially encapsulates the housing, wherein the overmold comprises a first component comprising an elastomeric material and a second component comprising a non-elastomeric material.    
   
   
       2 . The implantable medical device of  claim 1 , wherein the first component at least partially encapsulates the housing and the second component is positioned to at least partially surround the housing.  
   
   
       3 . The implantable medical device of  claim 1 , wherein the overmold is flexible.  
   
   
       4 . The implantable medical device of  claim 1 , wherein the elastomeric material comprises silicone.  
   
   
       5 . The implantable medical device of  claim 1 , wherein the non-elastomeric material comprises at least one of a polysulfone or a polyurethane.  
   
   
       6 . The implantable medical device of  claim 1 , further comprising a lead connection module within the overmold for connecting an external lead to electronics within the control module.  
   
   
       7 . The implantable medical device of  claim 1 , wherein the overmold comprises a first overmold, the implantable medical device further comprising a second overmold that at least partially encapsulates a lead connection module, wherein the second overmold is tethered to the first overmold.  
   
   
       8 . The implantable medical device of  claim 1 , wherein an edge of the overmold is tapered to provide a sloped transition between the implantable medical device and a surface of the patient, and an angle between the edge of the overmold and the surface of the patient is greater than approximately 90 degrees.  
   
   
       9 . The implantable medical device of  claim 8 , wherein the angle is within a range from approximately 120 to approximately 150 degrees.  
   
   
       10 . The implantable medical device of  claim 1 , further comprising a sloped interface element, separate from the overmold, which surrounds the overmold and provides a sloped transition between the implantable medical device and a surface of the patient, wherein an angle between an edge of the sloped interface element and the surface of the patient is greater than 90 degrees.  
   
   
       11 . The implantable medical device of  claim 1 , wherein at least one of the first or second components of the overmold is concave such that the overmold conforms substantially to a cranium of a patient.  
   
   
       12 . The implantable medical device of  claim 1 , wherein the overmold includes an external lead management structure for external leads being routed away from the implantable medical device.  
   
   
       13 . The implantable medical device of  claim 1 , wherein the overmold includes a removal assist structure for assisting in removal of the implantable medical device.  
   
   
       14 . The implantable medical device of  claim 1 , wherein the overmold includes a through-hole to receive an attachment mechanism for attaching the implantable medical device to a patient.  
   
   
       15 . The implantable medical device of  claim 1 , wherein the implantable medical device is adapted to be implanted on a cranium of a patient, and the overmold includes a cap to cover a hole through the cranium.  
   
   
       16 . The implantable medical device of  claim 1 , wherein the control module provides neurostimulation therapy to a patient.  
   
   
       17 . The implantable medical device of  claim 1 , wherein the control module comprises a first module, the implantable medical device further comprising a second module interconnected to the control module.  
   
   
       18 . The implantable medical device of  claim 17 , further comprising a motion reduction element to reduce motion between the control module and the second module.  
   
   
       19 . An implantable medical device comprising: 
 a control module comprising a housing; and    an overmold that at least partially encapsulates the housing, wherein the overmold comprises a first component that at least partially encapsulates the housing and a second component that is positioned to at least partially surround the housing and at least partially contact the housing.    
   
   
       20 . The implantable medical device of  claim 19 , wherein the first component comprises an elastomeric material, and the second component comprises a non-elastomeric material.  
   
   
       21 . The implantable medical device of  claim 19 , wherein the control module comprises a first module, the implantable medical device further comprising a second module interconnected to the control module.  
   
   
       22 . The implantable medical device of  claim 19 , further comprising a sloped interface element, separate from the overmold, which surrounds the overmold and provides a sloped transition between the implantable medical device and a surface of the patient, wherein an angle between an edge of the sloped interface element and the surface of the patient is greater than approximately 90 degrees.  
   
   
       23 . An implantable medical device comprising: 
 a control module comprising a housing; and    an overmold that at least partially encapsulates the housing; and    a sloped interface element separate from the overmold that at least partially surrounds the overmold and is tapered to provide a sloped transition between the overmold and a surface of the patient, wherein an angle between an edge of the sloped interface element and the surface of the patient is greater than approximately 90 degrees.    
   
   
       24 . The implantable medical device of  claim 23 , wherein the overmold is at least partially flexible.  
   
   
       25 . The implantable medical device of  claim 23 , wherein the angle is within a range from approximately 120 to approximately 150 degrees.  
   
   
       26 . The implantable medical device of  claim 23 , wherein the overmold comprises a first component that at least partially encapsulates the housing and a second component that is positioned to surround the housings, wherein the first component comprises an elastomeric material, and the second component comprises a non-elastomeric material.  
   
   
       27 . An implantable medical device adapted to be implanted on a cranium of a patient, the implantable medical device comprising: 
 a control module comprising a housing; and    an overmold that at least partially encapsulates the housing and comprises a cap to cover a hole through the cranium.    
   
   
       28 . The implantable medical device of  claim 27 , wherein the overmold comprises a first component that at least partially encapsulates the housing and a second component that is positioned to surround the housing.  
   
   
       29 . The implantable medical device of  claim 27 , wherein overmold comprises a first component comprising an elastomeric material and a second component comprising a non-elastomeric material.