Force sensors for surgical devices to prevent ingress of fluids

Abstract

A force sensor includes a substrate, a plurality of sensing elements, a seal, and a cover plate. The substrate includes a proximal surface and a distal surface, with the plurality of sensing elements coupled to the distal surface of the substrate. The seal includes a base wall and a flange extending proximally from the base wall. The flange is positioned against the distal surface of the substrate to define a cavity between the base wall of the seal and the distal surface of the substrate within which the plurality of sensing elements are disposed. The cover plate is positioned over the seal and fixed to the substrate. The cover plate applies a closure force on the seal to inhibit the ingress of fluids into the cavity.

1 - 12 . (canceled) 
     
     
         13 . A force sensor comprising:
 a substrate including a proximal surface and a distal surface;   a plurality of sensing elements coupled to the distal surface of the substrate;   a reservoir plate including a main body and a raised central portion having an opening defined therethrough, the reservoir plate mounted to the distal surface of the substrate, the plurality of sensing elements disposed within the opening and hermetically sealed therein; and   a cover plate positioned over the reservoir plate and welded to the substrate.   
     
     
         14 . The force sensor according to  claim 13 , wherein the substrate includes first and second lateral halves interconnected by an intermediate wall, the first lateral half being lower than the second lateral half. 
     
     
         15 . The force sensor according to  claim 14 , wherein the reservoir plate is welded to the first lateral half of the substrate, the main body of the reservoir plate having a height that is equal to a height difference between the first and second lateral halves. 
     
     
         16 . The force sensor according to  claim 13 , wherein a sealant is disposed over the plurality of sensing elements within the opening of the reservoir plate. 
     
     
         17 . The force sensor according to  claim 13 , wherein a seal is disposed over the reservoir plate, the seal including an end wall and a flange disposed around the entire outer perimeter of the end wall and extending proximally therefrom, the flange positioned against the distal surface of the substrate to define a cavity in which the raised central portion of the reservoir plate is housed, and the cover plate applies a closure force on the seal to prevent the ingress of fluids therein. 
     
     
         18 . The force sensor according to  claim 17 , further comprising a flex cable electrically coupled to the plurality of sensing elements and extending between the reservoir plate and the distal surface of the substrate. 
     
     
         19 . A surgical device comprising:
 a powered handle assembly;   an adapter assembly including a connector housing and a trocar connection housing;   an end effector releasably secured to the connector housing of the adapter assembly; and   the force sensor of  claim 13  disposed between the connector housing and the trocar connection housing, and configured to measure forces exhibited by the end effector along a load path.   
     
     
         20 . The force sensor according to  claim 13 , wherein the substrate includes a central aperture defined through the proximal and distal surfaces, and extending along a central longitudinal axis. 
     
     
         21 . The force sensor according to  claim 20 , wherein the reservoir plate is sized and shaped to cover a first lateral half of the distal surface of the substrate, the reservoir plate including a cutout dimensioned to align with the central aperture of the substrate. 
     
     
         22 . The force sensor according to  claim 20 , wherein the cover plate includes a central aperture defined therethrough that is sized and dimensioned to be coincident with the central aperture of the substrate. 
     
     
         23 . The force sensor according to  claim 13 , wherein the plurality of sensing elements are strain gauges. 
     
     
         24 . The force sensor according to  claim 13 , wherein the cover plate includes first and second rails seated against the main body of the reservoir plate and the distal surface of the substrate. 
     
     
         25 . The force sensor according to  claim 24 , wherein the cover plate includes a plurality of legs extending from the first and second rails, the plurality of legs engaged with side surfaces of the substrate.