Spinal implants with active sensing capabilities

Abstract

Load sensing spinal implants having at least one sensor and an antenna are disclosed. An example implant may include an interbody cage extending in a longitudinal direction from a proximal end to a distal end and in a widthwise direction from a first lateral end to a second lateral end; and an electronics portion including a housing defining a sealed cavity for supporting an electronics assembly and a battery therein. The implant may include at least one antenna in electrical communication with the electronics assembly; and at least one strain gauge configured to detect a localized force experienced by the interbody cage. The at least one antenna may be configured to transmit information received from the at least one strain gauge to an external device. The electronics assembly may be disposed on the side of the cage, a distal end of the cage, or inside a window of the cage.

1 . A load sensing spinal implant, comprising:
 an interbody cage extending in a longitudinal direction from a proximal end to a distal end and in a widthwise direction from a first lateral end to a second lateral end;   an electronics portion including a housing defining a sealed cavity for supporting an electronics assembly and a battery therein;   at least one antenna in electrical communication with the electronics assembly; and   at least one strain gauge configured to detect a localized force experienced by the interbody cage and being in electrical communication with the electronics assembly,   wherein the at least one antenna is configured to transmit information received from the at least one strain gauge to an external device.   
     
     
         2 . The load sensing spinal implant of  claim 1 , wherein the at least one antenna is configured to utilize a Medical Implant Communication System (MICS) technology. 
     
     
         3 . The load sensing spinal implant of  claim 1 , wherein the at least one antenna is configured to utilize a Bluetooth low energy (BLE) technology. 
     
     
         4 . The load sensing spinal implant of  claim 1 , wherein the electronics portion is disposed inside of a graft window of the interbody cage. 
     
     
         5 . The load sensing spinal implant of  claim 1 , wherein an overmold is formed over the electronics portion. 
     
     
         6 . The load sensing spinal implant of  claim 1 , wherein at least one pass through connection extends through a sidewall of the housing thereby placing the at least one antenna in electrical communication with the electronics assembly. 
     
     
         7 . The load sensing spinal implant of  claim 1 , wherein the housing further comprises a cover configured to seal an opening of the cavity for placing the electronics assembly therein. 
     
     
         8 . The load sensing spinal implant of  claim 1 , wherein the electronics assembly is coupled to an exposed side surface of the interbody cage. 
     
     
         9 . The load sensing spinal implant of  claim 1 , further comprising at least one of: a temperature sensor, an accelerometer sensor, a gyroscope sensor, and an impedance sensor. 
     
     
         10 . The load sensing spinal implant of  claim 1 , wherein the at least one strain gauge is disposed on an interior sidewall of a graft window of the interbody cage. 
     
     
         11 . The load sensing spinal implant of  claim 1 , wherein the electronics assembly further comprises a wake-up sensor configured to power up the electronics assembly and cause the at least one antenna to initiate a transmission of information to the external device. 
     
     
         12 . The load sensing spinal implant of  claim 1 , wherein the at least one strain gauge is disposed inside of the housing. 
     
     
         13 . The load sensing spinal implant of  claim 1 , wherein the electronics portion is disposed inside of a graft window of the interbody cage and the housing comprises a primary protrusion that extends into a first cavity in a side wall of the graft window. 
     
     
         14 . The load sensing spinal implant of  claim 13 , wherein the housing comprises a secondary protrusion that extends into a second cavity in a sidewall of the graft window. 
     
     
         15 . The load sensing spinal implant of  claim 1 , wherein the electronics portion is coupled to an interior sidewall of the interbody cage by a pin or a threaded screw. 
     
     
         16 . The load sensing spinal implant of  claim 1 , wherein the at least one antenna has a size and shape that generally corresponds to at least one interior sidewall of a graft window of the interbody cage. 
     
     
         17 . The load sensing spinal implant of  claim 1 , wherein the interbody cage is formed around the at least one antenna and, when viewed in plan view, the at least one antenna has a size and shape that generally corresponds to a size and shape of the interbody cage. 
     
     
         18 . A load sensing spinal implant, comprising:
 an interbody cage extending in a longitudinal direction from a proximal end to a distal end and in a widthwise direction from a first lateral end to a second lateral end, the interbody cage including a graft window;   an electronics portion including a housing defining a sealed cavity for supporting an electronics assembly and a battery therein;   an overmold portion surrounding the electronics portion thereby forming a hermetic seal;   at least one antenna in electrical communication with the electronics assembly and having a size and shape that generally corresponds to a size and shape of at least one sidewall of the graft window; and   at least one strain gauge configured to detect a localized force experienced by the interbody cage and being in electrical communication with the electronics assembly,   wherein the at least one antenna is configured to transmit information received from the at least one strain gauge to an external device.   
     
     
         19 . The load sensing spinal implant of  claim 18 , wherein:
 the at least one strain gauge is disposed outside of the housing and the overmold portion, and the overmold portion conforms to a size and shape of the graft window.   
     
     
         20 . A load sensing spinal implant, comprising:
 an interbody cage extending in a longitudinal direction from a proximal end to a distal end and in a widthwise direction from a first lateral end to a second lateral end;   an electronics portion including a housing defining a sealed cavity for supporting an electronics assembly and a battery therein;   at least one antenna in electrical communication with the electronics assembly; and   at least one strain gauge configured to detect a localized force experienced by the interbody cage and being in electrical communication with the electronics assembly, wherein the at least one antenna is configured to transmit information received from the at least one strain gauge to an external device,   wherein the interbody cage comprises an exposed cavity at a distal end thereof having a curved sidewall, the electronics portion is disposed inside of the exposed cavity, and the housing conforms to the curved sidewall, and   wherein the at least one strain gauge is disposed inside of the housing and has a geometry corresponding to the curved sidewall.