Patent Description:
Force sensors (e.g., load reading sensors) are known, and have been used to enhance control of functions in a surgical device, such as a surgical stapling instrument. By using a load reading sensor, the clamping, stapling, and cutting forces of the surgical device can be monitored and used to facilitate these various functions. The load reading sensor can be used to detect pre-set loads and cause the surgical device to react to such a response. For example, during clamping of thick tissue, the load will rise to a pre-determined limit where the surgical device can slow clamping to maintain the clamping force as the tissue relaxes. This allows for clamping of thick tissue without damage to such tissue (e.g., serosa tears). One such example is the firing of a circular stapler type surgical device to create an anastomosis for a powered EEA device (e.g., End-to-End Anastomosis device). The intelligence of such a surgical device is at a higher product cost compared to currently available disposable units and thus would benefit if such intelligent devices are reusable.

Reusable surgical devices must be cleaned (e.g., disinfected) using high pH solutions and sterilized prior to subsequent uses. The most common method of sterilization is the use of autoclaving. Autoclaving utilizes high pressure superheated steam (e.g., <NUM> kiloPascals (<NUM> PSI) @ <NUM> for <NUM> minutes). Such an environment is known to damage various electronic components and thus a need exists for sensors that can withstand high pH cleaning and sterilizations.

<CIT> discloses adapter assemblies for use with and to electrically and mechanically interconnect electromechanical surgical devices and surgical loading units, and surgical systems including hand held electromechanical surgical devices and adapter assemblies for connecting surgical loading units to the hand held electromechanical surgical devices. This patent document discloses a strain gauge (<NUM>), fig 12A, 12B comprising a central aperture.

The force sensors of the present disclosure are hermetically sealed and configured to withstand environmental stresses associated with cleaning and sterilization (e.g., autowashing and/or autoclaving), thereby rendering the force sensors more durable for re-use. The invention is defined in claims <NUM> and <NUM>. Further embodiments of the invention are defined in the dependent claims.

In one aspect of the present disclosure, a force sensor for use in a powered surgical device, wherein the force sensor includes a substrate, a plurality of sensing elements, and a plate. The substrate includes a central aperture extending along a longitudinal axis of the substrate, and has a proximal surface, a distal surface, a first side surface, a second side surface, a top surface, and a bottom surface. A recess is defined within at least one of the distal surface, the first side surface, the second side surface, the top surface, or the bottom surface of the substrate. The plurality of sensing elements are disposed within the recess, and the plate is disposed over the recess and mounted to the substrate to hermetically seal the plurality of sensing elements within the substrate. The force sensor is sealed and configured to withstand environmental stresses associated with cleaning and sterilization.

In embodiments, the recess is a first recess defined in the first side surface of the substrate. The first recess includes a back wall, a proximal-facing wall, a distal-facing wall, a top wall, and a bottom wall. In some embodiments, the back wall, the proximal-facing wall, the distal-facing wall, the top wall, and the bottom wall are all substantially planar. In some embodiments, the back wall is angled with respect to the longitudinal axis of the substrate, and the proximal-facing and distal-facing walls are angled with respect to the back wall. The substrate may include a second recess defined in the second side surface of the substrate.

The substrate may include a through hole extending through a wall of the recess and the proximal surface of the substrate. In embodiments, at least one wire is coupled to the plurality of sensing elements disposed within the recess and extends through the through hole. In some embodiments, a sealant is disposed within the through hole filling a space defined between an outer diameter of the wire and an inner diameter of the through hole.

The force sensor may include a pin block assembly mounted to the substrate and in communication with the through hole of the substrate. In embodiments, the pin block assembly includes a plurality of conductive pins, a plurality of glass seals, and a pin block housing including a plurality of openings. Each pin of the plurality of conductive pins extends through a glass seal of the plurality of glass seals which is disposed within an opening of the plurality of openings of the pin block housing. In some embodiments, the pin block housing is disposed within the through hole of the substrate. In certain embodiments, a distal portion of each pin of the plurality of pins is disposed within the recess of the substrate, and a proximal portion of each pin of the plurality of pins is disposed outside of the substrate.

In some embodiments, the pin block housing of the pin block assembly is disposed within a pin block cover, and the pin block cover is mounted to the substrate. In certain embodiments, a distal portion of each pin of the plurality of pins is disposed within the pin block cover, and a proximal portion of each pin of the plurality of pins extends proximally through the pin block cover.

The pin block assembly may be welded to the substrate. The plate may be welded to the first side surface of the substrate. The first side surface may include a recessed lip defined around an inner perimeter thereof, and the plate may be received within the recessed lip.

The substrate may include wall sections that define the central aperture, and the wall sections may be angled with respect to the longitudinal axis of the substrate.

In embodiments, the recess is a distal recess defined in the distal surface of the substrate. In embodiments, the recess is defined in at least two of the distal surface, the first side surface, the second side surface, the top surface, or the bottom surface of the substrate.

In embodiments, the force sensor is disposed between a connector housing and a trocar connector housing of an adapter assembly of a surgical device. The surgical device includes a powered handle assembly, the adapter assembly, and an end effector releasably secured to the connector housing of the adapter assembly. The force sensor is configured to measure forces exhibited by the end effector along a load path.

In another aspect of the present disclosure, a force sensor includes a substrate, a plurality of sensing elements, a plate, and a pin block assembly. The substrate includes a proximal surface, a distal surface, a first side surface, a second side surface, a top surface, and a bottom surface. A recess is defined within at least one of the distal surface, the first side surface, the second side surface, the top surface, or the bottom surface of the substrate, and a through hole extends through the substrate from the recess to the proximal surface. The plurality of sensing elements are disposed within the recess, and the plate is disposed over the recess and mounted to the substrate. The pin block assembly is mounted to the substrate and is in communication with the through hole of the substrate. The pin block assembly includes a plurality of conductive pins, a plurality of glass seals, and a pin block housing including a plurality of openings. Each pin of the plurality of conductive pins extends through a glass seal of the plurality of glass seals which is disposed within an opening of the plurality of openings of the pin block housing. The plate and the pin block assembly hermetically seal the plurality of sensing elements within the substrate. The pin block housing and/or the plate may be welded to the substrate.

The pin block housing may be disposed within the through hole of the substrate. In some embodiments, a distal portion of each pin of the plurality of pins is disposed within the recess of the substrate, and a proximal portion of each pin of the plurality of pins is disposed outside of the substrate.

The pin block housing of the pin block assembly may be disposed within a pin block cover. The pin block cover may be mounted to the substrate and in fluid communication with the through hole of the substrate. In some embodiments, the pin block cover is welded to the pin block housing around an entire inner perimeter of a proximal opening of the pin block cover. In some embodiments, a distal portion of each pin of the plurality of pins is disposed within the pin block cover, and a proximal portion of each pin of the plurality of pins extends proximally through the pin block cover.

Other aspects, features, and advantages will be apparent from the description, drawings, and the claims.

Various aspects of the present disclosure are described herein below with reference to the drawings, which are incorporated in and constitute a part of this specification, wherein:.

The force sensors of the present disclosure include hermetically sealed substrates that protect sensing elements of, e.g., surgical devices, from harsh environments, such as autowashing and/or autoclaving. The force sensors include a substrate including at least one recess defined therein for housing sensing elements, such as strain gauges and their supporting electronics, which are sealed from the outside environment by the use of one or more plates, sealants, and/or pin block assemblies to create a protective leak-proof barrier to the sensing elements.

Embodiments of the present disclosure are now described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. Throughout this description, the term "proximal" refers to a portion of a device, or component thereof, that is closer to a hand of a user, and the term "distal" refers to a portion of the device, or component thereof, that is farther from the hand of the user. Directional reference terms, such as "top," "bottom," "back," "side," and the like, are intended to ease description of the embodiments and are not intended to have any limiting effect on the ultimate orientations of the surgical devices, or any parts thereof.

Turning now to <FIG>, a surgical device <NUM>, in accordance with an embodiment of the present disclosure, is in the form of a powered handheld electromechanical instrument, and includes a powered handle assembly <NUM>, an adapter assembly <NUM>, and a tool assembly or end effector <NUM> including a loading unit <NUM> having a plurality of staples (not shown) disposed therein and an anvil assembly <NUM> including an anvil head 34a and an anvil rod 34b. The powered handle assembly <NUM> is configured for selective connection with the adapter assembly <NUM> and, in turn, the adapter assembly <NUM> is configured for selective connection with the end effector <NUM>.

While described and shown as including adapter assembly <NUM> and end effector <NUM>, it should be understood that a variety of different adapter assemblies and end effectors may be utilized in the surgical device of the present disclosure. For a detailed description of the structure and function of exemplary surgical devices, reference may be made to commonly owned <CIT>, and <CIT>.

With continued reference to <FIG>, the handle assembly <NUM> includes a handle housing <NUM> housing a power-pack (not shown) configured to power and control various operations of the surgical device <NUM>, and a plurality of actuators <NUM> (e.g., finger-actuated control buttons, knobs, toggles, slides, interfaces, and the like) for activating various functions of the surgical device <NUM>. For a detailed description of an exemplary handle assembly, reference may be made to the '<NUM> application.

Referring now to <FIG>, in conjunction with <FIG>, the adapter assembly <NUM> includes a proximal portion 20a configured for operable connection to the handle assembly <NUM> (<FIG>) and a distal portion 20b configured for operable connection to the end effector <NUM> (<FIG>). The adapter assembly <NUM> includes an outer sleeve <NUM>, and a connector housing <NUM> secured to a distal end of the outer sleeve <NUM>. The connector housing <NUM> is configured to releasably secure an end effector, e.g., the end effector <NUM> (<FIG>), to the adapter assembly <NUM>.

The adapter assembly <NUM> will only further be described to the extent necessary to fully disclose the aspects of the present disclosure. For detailed description of an exemplary adapter assembly, reference may be made to the '<NUM> application.

With reference now to <FIG>, in conjunction with <FIG>, the adapter assembly <NUM> further includes a trocar assembly <NUM> that extends through a central aperture <NUM> (see e.g., <FIG>) of a force sensor <NUM> and a central aperture <NUM> (<FIG>) of a trocar connection housing <NUM>. The trocar connection housing <NUM> releasably secures the trocar assembly <NUM> relative to the outer sleeve <NUM> (<FIG>) of the adapter assembly <NUM>. For a detailed description of an exemplary trocar connection housing, reference may be made to <CIT>.

The force sensor <NUM> is disposed between the trocar connection housing <NUM> and the connector housing <NUM> of the adapter assembly <NUM>, and is configured to measure forces along a load path. As shown in <FIG> and <FIG>, the trocar connection housing <NUM> includes a distal surface 28a which interfaces with, and loads a proximal surface 110a of a body or substrate <NUM> of the force sensor <NUM> at proximal load contact areas "Cp". As shown in <FIG> and <FIG>, a proximal surface 24a of the connector housing <NUM> defines a contact surface which loads a distal surface 110b of the substrate <NUM> of the force sensor <NUM> at distal load contact areas "Cd. " Thus, for example, as the anvil assembly <NUM> (<FIG>) is approximated towards the loading unit <NUM> of the end effector <NUM> during clamping and/or stapling of tissue, the anvil head 34a applies uniform pressure in the direction of arrow "A" (<FIG>) against the distal end 24b of the connector housing <NUM> which, in turn, is transmitted to the distal load contact areas "Cd" of the force sensor <NUM>.

Referring now to <FIG>, the force sensor <NUM> includes a substrate <NUM>, and first and second plates <NUM>, <NUM> bonded to the substrate <NUM> in a fluid tight manner. A central aperture <NUM> is defined through the substrate <NUM> and extends along a central longitudinal axis "X" of the substrate <NUM>. The substrate <NUM> includes a proximal surface 110a and a distal surface 110b which are load bearing surfaces, as described above, that allow the substrate <NUM> to compress when loaded by the surgical device <NUM> (<FIG>). The proximal surface 110a of the substrate <NUM> includes a central region 112a and lateral regions 112b extending laterally from the central region 112a. The central region 112a is substantially planar and extends along a plane lying substantially perpendicular to the central longitudinal axis "X" of the substrate <NUM>. The lateral regions 112b are substantially planar and extend along planes disposed at angles with respect to the central region 112a that slope distally from the central region 112a to first and second side surfaces 110c, 110d of the substrate <NUM>.

The first and second side surfaces 110c, 110d and top and bottom surfaces 110e, 110f extend between the proximal and distal surfaces 110a, 110b of the substrate <NUM>. The first and second side surfaces 110c, 110d each define a recess <NUM>, <NUM>, respectively, therein for bonding of sensing elements "Se" (<FIG>), for example, strain gauges, therein. The first and second side surfaces 110c, 110d are substantially a mirror image of each other and allows for uniform strain along the force sensor <NUM>. It should be understood, however, that the substrate <NUM> may be formed to include only one recess in either the first or second side surfaces 110c, 110d while maintaining a flex-type configuration (such as that of a simply supported beam) that allows for large strain upon deformation which, in turn, creates more signal and resists transient thermos or thermal variation shifts. The force sensor <NUM> self-aligns regardless of tolerance variation and upon loading, is forced against proximal load contact areas "Cp" and will flex, having constant flexure along its length.

The first and second recesses <NUM>, <NUM> are each defined by a back wall 114a, a proximal-facing wall 114b, a distal-facing wall 114c disposed in spaced, opposed relation to the proximal-facing wall 114b, a top wall 114c, and a bottom wall 114d disposed in spaced, opposed relation to the top wall 114c. The back wall 114a extends along a plane that is substantially parallel to the central longitudinal axis "X" of the substrate <NUM>. The proximal-facing wall 114b, the distal-facing wall 114c, the top wall 114c, and the bottom wall 114d extend outwardly from the back wall 114a and are oriented at about <NUM>° relative to the back wall 114a. A through hole <NUM> extends through the distal-facing wall 114c of the first and/or second recesses <NUM>, <NUM> and the respective lateral region 112b of the proximal surface 110a of the substrate <NUM>. The angle of the lateral region 112b of the proximal surface 110a provides a strain relief on wires (see e.g., flex cable "F" in <FIG>) passed therethrough.

As shown in <FIG>, sensing elements "Se", e.g., strain gauges, are disposed within the first recess <NUM>, along with associated components thereof (not shown), e.g., media layers, films, protective coatings, circuitry including electronic components, such as resistors, and conductive wires and/or traces, electronic and/or solder connectors, etc. The sensing elements "Se" are mounted in specific locations within the first recess <NUM> and in embodiments, to the back wall 114a of the first recess <NUM>, and are connected together with a series of wires (not shown) to form a resistance bridge, e.g., a Wheatstone bridge, that can read a linear strain response of the substrate <NUM> when compressed, as is within the purview of those skilled in the art. In embodiments, the linear strain response is read using a single conditioner which may include an operational amplifier to enhance the signal.

A flex cable "F," which is coupled to the sensing elements "Se," exits the first recess <NUM> through the through hole <NUM> for electrical connection with electronics of the surgical device <NUM> (<FIG>). For example, the flex cable "F" (<FIG>) extends through the through hole <NUM> of the substrate <NUM> for electrical connection with wires "W" (<FIG>) coupled to the trocar connection housing <NUM> which, in turn, are electrically connected to electronics (not shown) of the surgical device <NUM> (<FIG>) for supplying power and reading force responses from the force sensor <NUM>. Thus, when surgical device <NUM> (<FIG>) is used in such a way to cause compression on the force sensor <NUM>, the surgical device <NUM> can be programmed to perform a function with respect to the measured force.

A sealant <NUM> is disposed within the through hole <NUM> in a fluid tight manner with the flex cable "F" to maintain a hermetic seal within the first recess <NUM>. The sealant <NUM> may be, for example, epoxies, RTV sealants, urethanes, acrylics, among other materials and/or encapsulates that can withstand sterilization, disinfection, and/or cleaning procedures to which the adapter assembly <NUM> (<FIG>) may be subjected, as is within the purview of those skilled in the art.

The first and second plates <NUM>, <NUM> are dimensioned to cover and seal the first and second recesses <NUM>, <NUM>, respectively. The first and second plates <NUM>, <NUM> are mounted on the first and second side surfaces 110c, 110d, respectively, and secured thereto in a fluid tight manner. In embodiments, the first and second plates <NUM>, <NUM> are welded to the first and second side surfaces 110c, 110d, respectively, by, for example, laser or electronic beam welding, around the entirety of an outer perimeter "Po" of the first and second plates <NUM>, <NUM> to form a hermetic seal and leak-proof barrier to protect the sensing elements "Se" and associated components from the external environment (e.g., during cleaning and/or sterilization processes). The first and second plates <NUM>, <NUM> may be fabricated from a metal, such as stainless steel (e.g., <NUM>/<NUM>-<NUM> stainless steel), among other materials capable of achieving a desired yield as within the purview of those skilled in the art. The first and second plates <NUM>, <NUM> have a minimal thickness so as to bend and to allow for a responsive signal from the substrate <NUM> upon loading.

In embodiments, the through hole <NUM> may be a series of through holes through which individual wires and/or cables may pass. In some embodiments, individual pins may be sealed within the series of through holes, for example, with sealants disposed within each through hole as described above, glass seals disposed within each through hole as described below, and/or o-rings placed on the pins within the each through hole.

While only the first recess <NUM> is shown having sensing elements "Se" mounted therein, and having a through hole <NUM> in communication therewith, it should be understood that, depending on the desired sensor configuration, the sensing elements "Se" may be mounted in either or both of the first or second recesses <NUM>, <NUM>, and either or both of the first or second recesses <NUM>, <NUM> may include a through hole <NUM> therethrough. In embodiments, both the first and second recesses may include sensing elements, through holes, and first and second plates mounted thereto. In embodiments, the sensing elements may be disposed in only one of the first or second recesses and a through hole may be defined in only the recess including the sensing elements. In some embodiments in which only one of the first or second recesses includes sensing elements, only the respective first or second plate may be secured to the first or second side surface containing the sensing elements. In certain embodiments, both the first and second plates may be secured to the substrate where a wire trace is utilized for electrical communication between the first and second recesses.

Referring now to <FIG>, a force sensor <NUM>' is shown in accordance with another embodiment of the present disclosure. The force sensor <NUM>' is substantially the same as the force sensor <NUM>, and therefore will only be described herein with respect to the differences therebetween. The force sensor <NUM>' includes a substrate <NUM>', a first plate <NUM>', and a second plate (not shown). The substrate <NUM>' includes a proximal surface 110a, a distal surface 110b, a first side surface 110c' defining a first recess <NUM>' therein, a second side surface 110d' defining a second recess (not shown) therein, and top and bottom surfaces 110e, 110f. While the first side surface 110c' is described singularly herein, it should be understood that the second side surface 110d' may be substantially similar to the first side surface 110c', or the structure may vary depending on the desired sensor configuration as described above with regard to substrate <NUM>.

The first side surface 110c' includes a recessed lip <NUM> extending around an inner perimeter thereof. The recessed lip <NUM> is configured to receive the first plate <NUM>' such that the first plate <NUM>' is disposed in spaced relation relative to the sensing elements "Se" disposed within the first recess <NUM>' and is flush with, and sealed to, the first side surface 110c' of the substrate <NUM>', for example, by welding the first plate <NUM>' around an entire outer perimeter "Po" of the first plate <NUM>'.

Referring now to <FIG>, a force sensor <NUM> is shown in accordance with another embodiment of the present disclosure. The force sensor <NUM> is substantially similar to the force sensor <NUM> and therefore, will only be described herein with respect to the differences therebetween. The force sensor <NUM> includes a substrate <NUM> having a central aperture <NUM> defined therethrough. The substrate <NUM> includes a proximal surface 210a, a distal surface 210b, a first side surface 210c defining a first recess <NUM> therein, a second side surface 210d defining a second recess <NUM> therein, and top and bottom surfaces 210e, 210f. First and second plates <NUM>, <NUM> are configured to be mounted and sealed to the first and second side surfaces 210c, 210d, respectively, to hermetically seal the first and second recesses <NUM>, <NUM>. It should be understood that while the first and second plates <NUM>, <NUM> are shown mounted to the first and second side surfaces 210c, 210d of the substrate <NUM>, the first and second side surfaces 210c, 210d may each include a recessed lip configured to receive the first and second plates <NUM>, <NUM> therein, as described above with regard to substrate <NUM>'.

As specifically shown in <FIG>, the central aperture <NUM> of force sensor <NUM> includes relief features <NUM> to maintain angled wall sections <NUM> that define the central apertures <NUM>. The first and second recesses <NUM>, <NUM> are each defined by a back wall 214a, a proximal-facing wall 214b, a distal-facing wall 214c disposed in spaced, opposed relation to the proximal-facing wall 214b, a top wall 214c, and a bottom wall 214d disposed in spaced, opposed relation to the top wall 214c. The back wall 214a extends along a plane that is angled with respect to a central longitudinal axis "X" of the substrate <NUM>, such that the respective first or second recess <NUM>, <NUM> tapers distally. The proximal-facing wall 214b, the distal-facing wall 214c, the top wall 214c, and the bottom wall 214d extend outwardly from the back wall 214a. The proximal-facing wall 214b and the distal-facing wall 214c taper laterally towards the respective first or second side surface 210c, 210d, and the top wall 214c and the bottom wall <NUM> are substantially perpendicular to the back wall 214a. A through hole <NUM> extends through the proximal-facing wall 214b of the first recess <NUM> and the distal surface 110b of the substrate <NUM>.

The angled wall sections <NUM> of the central aperture <NUM>, as well as the angled walls (e.g., the back wall 214a, the proximal-facing wall 214b, and the distal-facing wall 214c) of the first and second recesses <NUM>, <NUM> eliminates or reduces pure compression during loading of the force sensor <NUM>, allowing the substrate <NUM> to be subjected to both compression and bending. The configuration of the first and second recesses <NUM>, <NUM> allows for increased strain (e.g., substrate deflection) which can produce a larger strain range which, in turn, allows for more signal response from the force sensor <NUM> to improve accuracy.

As described above with respect to substrate <NUM>, sensing elements (not shown) are disposed within the first and/or second recess <NUM>, <NUM>, along with and associated components thereof (not shown), a flex cable (not shown) exits the first and/or second recess <NUM>, <NUM> via the through hole <NUM> of the substrate <NUM>, and a sealant (not shown) is disposed within the through hole <NUM> in a fluid tight manner with the flex cable to maintain a hermetic seal within the first and/or second recess <NUM>, <NUM>. It should be understood the structure of the first and/or second recesses <NUM>, <NUM>, as well as the through hole <NUM> may vary, as described above with regard to substrate <NUM>, depending on the desired sensor configuration.

Referring now to <FIG>, a force sensor <NUM> is shown in accordance with another embodiment of the present disclosure. The force sensor <NUM> includes a substrate <NUM>, first and second plates <NUM>, <NUM>, and a pin block assembly <NUM>. The substrate <NUM> is substantially similar to the substrates <NUM>, <NUM>' described above and therefore, will only be described herein with respect to the differences therebetween. The substrate <NUM> includes a proximal surface 310a and a distal surface 310b, which are load bearing surfaces as described above, a first side surface 310c including a first recess <NUM> defined therein, and a second side surface 310d including a second recess <NUM> defined therein. Sensing elements "Se" are mounted inside the first and/or second recesses <NUM>, <NUM> of the substrate <NUM>, as described above, for example, with regard to substrate <NUM>, and the first and second plates <NUM>, <NUM> are mounted over the first and second recesses <NUM>, <NUM>, respectively, and sealed to the respective first and second side surfaces 310c, 310d (e.g., by welding).

While each of the first and second recesses <NUM>, <NUM> are shown having a back wall 314a, a proximal-facing wall 314b, a distal-facing wall 314c, a top wall 314d, and a bottom wall 314e that are all planar, it should be understood that the first and second recesses <NUM>, <NUM> may include angled walls as described above with respect to first and second recesses <NUM>, <NUM> of substrate <NUM> of force sensor <NUM>. Additionally, while the first and second plates <NUM>, <NUM> are shown as being received within recessed lips <NUM> of the respective first and second side surfaces 310c, 310d, it should be understood that the first and second plates <NUM>, <NUM> may overly the first and second side surfaces 310c, 310d as described above, for example, with respect to force sensor <NUM>.

As specifically shown in <FIG>, the proximal surface 310a of the substrate <NUM> is a stepped surface including a central region 312a, lateral regions 312b, and intermediate regions 312c interconnecting the central and lateral regions 312a, 312b. The central region 312a is substantially planar and extends along a plane lying substantially perpendicular to the central longitudinal axis "X" of the substrate <NUM>, and the lateral regions 312b are also planar and extend along a plane lying substantially perpendicular to the central longitudinal axis "X" of the substrate <NUM> in longitudinally spaced and distal relation to the central region 312a. The intermediate regions 312c are substantially planar and extend along a plane lying substantially parallel to the central longitudinal axis "X" of the substrate <NUM>. It should be understood that the proximal surface 310a may also be configured to include angled lateral walls as described, for example, with respect to proximal surface 110a of substrate <NUM> of force sensor <NUM>, and conversely, the proximal surfaces 110a, 210a of the substrates <NUM>, <NUM>', <NUM> may alternatively include the stepped configuration of proximal surface 310a of substrate <NUM>.

A through hole <NUM> is defined in the substrate <NUM> that extends through the distal-facing wall 314c of the first and/or second recess <NUM>, <NUM> and a respective lateral region 312b of the proximal surface 310a of the substrate <NUM> such that the first and/or second recess <NUM>, <NUM> is in communication with the exterior of the substrate <NUM>. In some embodiments, a pass through <NUM> (see e.g., <FIG>) may be provided in the substrate <NUM> adjacent the through hole <NUM> for passage of a ground wire "Wg.

As best seen in <FIG>, the pin block assembly <NUM> is disposed and fixedly secured within the through hole <NUM> of the first recess <NUM> of the substrate <NUM>. However, it should be understood that either or both the first or second recess <NUM>, <NUM> may include a pin block assembly <NUM>. As shown in <FIG>, the pin block assembly <NUM> includes a plurality of conductive pins <NUM>, with each pin <NUM> extending through a glass substrate or seal <NUM> disposed within an opening <NUM> of a pin block housing <NUM>. The plurality of conductive pins <NUM> are formed from metals, such as copper, iron, nickel and alloys thereof. In embodiments, the plurality of conductive pins <NUM> are formed from low thermal expansion alloys, such as Alloy <NUM> (NILO®, which is a registered trademark owned by Inco Alloys International, Inc. Each conductive pin <NUM> includes a proximal portion 342a, a distal portion 342b, and a central portion 342c disposed therebetween. The central portion 342c is disposed within the glass substrate <NUM> and the proximal and distal portions 342a, 342b extend proximally and distally, respectively, therefrom.

The pin block housing <NUM> includes a plurality of openings <NUM> defined therethrough that correspond to the desired number of conductive pins <NUM>. The conductive pins <NUM> are sealed with the pin block housing <NUM> by the glass substrates <NUM>. The glass substrates <NUM> are formed from glass, silicates, ceramics, and composites thereof that are capable of withstanding large temperature variations associated with, for example, autoclaving and/or autowashing procedures, and, in some embodiments, the glass substrates have an internal porosity which provides flexibility to the glass substrate to minimize or prevent fracture and/or breakage thereby strengthening the seal. In embodiments, the glass substrates <NUM> are formed from a polycrystalline ceramic, such as KRYOFLEX®, which is a registered trademark owned by Pacific Aerospace and Electronics, Inc.

In a method of forming the pin block assembly <NUM>, the pin block housing <NUM> is placed in a fixture and each conductive pin <NUM> is positioned through, and centered within, an opening <NUM> of the pin block housing <NUM>. Glass is heated to its melting point and poured into each opening <NUM> so that the glass flows into and fills the space between the inner diameter of the opening <NUM> of the pin block housing <NUM> and the outer diameter of the conductive pin <NUM>. Upon cooling, the glass solidifies and seals the conductive pins <NUM> to the pin block housing <NUM>. In embodiments, solid glass particles are pre-assembled and heated to allow the glass to flow and make the seal.

Depending on the choice of materials, in another method of forming the pin block assembly <NUM>, the pin block housing <NUM> may also be heated such that the inner diameter of the openings <NUM> expands upon heating and then shrinks upon cooling to form a compression seal thereby enhancing the seal of the pin block assembly <NUM>. For example, materials for various components of a pin block assembly may be selected based on, among other things, their coefficient of thermal expansion. In embodiments, the pin block housing <NUM> is formed from <NUM>-<NUM> PH stainless steel and the conductive pins <NUM> are formed from NILO®, a nickel-iron alloy which has minimal to no thermal expansion. When heated, the openings <NUM> of the pin block housing <NUM> that will contain the glass seals <NUM> expand. After the glass is melted and the pin block assembly <NUM> is cooled, the openings <NUM> shrink and compress the conductive pins <NUM> (that did not expand or that minimally expanded upon heating), thereby forming a compression seal.

Referring again to <FIG>, the pin block housing <NUM> is positioned within the through hole <NUM> of the substrate <NUM> and is secured therein in a fluid tight manner. In embodiments, the pin block housing <NUM> is welded along its entire outer perimeter "Po" to the substrate <NUM> to form a fully hermetic assembly of the pin block assembly <NUM> to the substrate <NUM>. As the conductive pins <NUM> are sealed within the pin block housing <NUM> via the glass substrates <NUM> and the pin block housing <NUM> is welded to the substrate <NUM>, the entire force sensor <NUM> is hermetically sealed without the use of sealants. It should be understood that, for example, the substrates <NUM>, <NUM>', <NUM> may include a pin block assembly through the through hole(s) of the substrates <NUM>, <NUM>', <NUM> as an alternative to the use of the sealants <NUM>. The integrity of glass seals is not sacrificed over time by chemical attack and/or degradation which may occur with sealants. Sealants may break down over time and, if not processed properly and/or applied correctly, may leak. Glass seals, on the other hand, are highly reliable and consistent once the process and components are dialed in.

As shown, for example, in <FIG>, the proximal portions 342a of the plurality of conductive pins <NUM> are disposed external of the substrate <NUM> and the distal portions 342b of the plurality of conductive pins <NUM> are within the first recess <NUM> of the substrate <NUM>. Wires (not shown) are connected (e.g., soldered) to the sensing elements "Se" which are disposed within the first recess <NUM> of the substrate <NUM> in a bridge configuration (e.g., a Wheatstone bridge), and soldered to the distal portions 342b of the plurality of conductive pins <NUM> so that electrical signals may exit the substrate <NUM> in order to supply power and read force responses from the force sensor <NUM>.

As shown in <FIG>, the force sensor <NUM> is disposed between a trocar connection housing <NUM> and a connector housing <NUM> of an adapter assembly <NUM>' of a surgical device <NUM> (<FIG>) in a similar manner as force sensors <NUM>, <NUM>', <NUM> to measure forces along a load path and enhance control of a function of the surgical device <NUM>, as described in further detail below.

Referring now to <FIG>, another embodiment of a force sensor <NUM> is shown. The force sensor <NUM> includes a substrate <NUM>, a first or distal plate <NUM>, and a pin block assembly <NUM>. The substrate <NUM> includes a central aperture <NUM> defined therethrough and extending between a proximal surface 410a and a distal surface 410b. The proximal surface 410a interfaces with a trocar connection housing <NUM> (see e.g., <FIG>), and the distal surface 410b interfaces with a connector housing <NUM> (see e.g., <FIG>). The proximal and distal surfaces 410a, 410b are load bearing surfaces that allow the substrate <NUM> to flex when loaded by a surgical device <NUM> (<FIG>), and include proximal and distal load contact areas "Cp" and "Cd," respectively, as described above, for example, with respect to force sensor <NUM>.

The proximal surface 410a of the substrate <NUM> is a stepped surface that is substantially similar to the proximal surface 310a of substrate <NUM>, described above, and includes a central region 412a which is an outwardly protruding loading portion, lateral regions 412b, and intermediate regions 412c interconnecting the central and lateral regions 412a, 412b. The distal surface 410b is a substantially planar surface including a distally extending flange <NUM> extending around the central aperture <NUM> of the substrate <NUM>.

As shown in <FIG>, the substrate <NUM> includes a through hole <NUM> extending through the distal surface 410b and the lateral region 412b of the proximal surface 410a. The through hole <NUM> is aligned with the pin block assembly <NUM> which is secured to the lateral region 412b of the proximal surface 410a of the substrate <NUM>. Optionally, in some embodiments, as shown for example, in <FIG>, a hole <NUM> is defined in the distal surface 410b and extends at least partially into the substrate <NUM>, in a location symmetrically opposed to through hole <NUM>, to equalize stresses on the substrate <NUM> during flexing of the substrate <NUM>.

As shown in <FIG>, sensing elements "Se" are bonded to the distal surface 410b of the substrate <NUM>. As specifically shown in <FIG>, the distal plate <NUM> includes a substantially planar end wall <NUM> and a proximally facing flange <NUM> extending around the end wall <NUM>, such that when the distal plate <NUM> is mounted on the distal surface 410b of the substrate <NUM> a cavity or recess <NUM> (shown in phantom) is defined between the end wall <NUM> of the distal plate <NUM> and the distal surface 410b of the substrate <NUM>, providing space and clearance for the sensing elements "Se" and associated components (not shown). The distal plate <NUM> is secured to the distal surface 410b of the substrate <NUM> in a fluid tight manner. In embodiments, the distal plate <NUM> is welded, for example, by laser or electronic beam welding, to the distal surface 410b of the substrate <NUM> around the entirety of an outer perimeter "Po" and the entirety of an inner perimeter "Pi" of the distal plate <NUM> to form a hermetic seal to protect the sensing elements "Se" and associated components from the external environment, such as, for example, during sterilizing and/or autoclaving processes. The distal plate <NUM> has a minimal thickness so as to bend and to allow for a responsive signal from the substrate <NUM> upon loading. In embodiments, the distal plate <NUM> has a thickness of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), and in some embodiments, about <NUM> (<NUM> inches).

As shown in <FIG>, in conjunction with <FIG> and <FIG>, the pin block assembly <NUM> includes a plurality of conductive pins <NUM>, with each pin <NUM> extending through a glass substrate or seal <NUM> disposed within an opening <NUM> of a pin block housing <NUM> which is housed within a pin block cover <NUM>. The pin block cover <NUM> includes a proximal opening <NUM> through which the plurality of conductive pins <NUM> extend. The pin block housing <NUM> and the pin block cover <NUM> are secured together, e.g., by welding, along the entire inner perimeter "Pi" of the proximal opening <NUM> of the pin block cover <NUM>. Each conductive pin <NUM> includes a proximal portion 442a, a distal portion 442b, and a central portion 442c (shown in phantom) disposed therebetween. The central portion 442c is disposed within the glass substrate <NUM> and the proximal and distal portions 442a, 442b extend proximally and distally, respectively, therefrom.

The pin block housing <NUM> includes a plurality of openings <NUM> defined therethrough that correspond to the desired number of conductive pins <NUM>. The conductive pins <NUM> are sealed with the pin block housing <NUM> by the glass substrates <NUM> as described, for example, above with regard to pin block assembly <NUM>. As shown in <FIG>, the distal portions 442b of the conductive pins <NUM> are disposed within the pin block cover <NUM>, and the proximal portions 442a of the plurality of conductive pins <NUM> extend proximally out through the pin block cover <NUM>.

As shown in <FIG>, the pin block cover <NUM> is secured (e.g., by welding) to the lateral region 412b of the proximal surface 410a of the substrate <NUM> around the entirety of an outer perimeter "Pp" of the pin block cover <NUM>, such that the distal portions 442b of the plurality of conductive pins <NUM> are hermetically sealed within the pin block assembly <NUM>. Wires (not shown) are connected (e.g., soldered) to the sensing elements "Se" (<FIG>) of the substrate <NUM> in a bridge configuration (e.g., a Wheatstone bridge), passed through the through hole <NUM>, and soldered to the distal ends 442b of the plurality of conductive pins <NUM> disposed within the pin block cover <NUM> so that electrical signals may exit the substrate <NUM> in order to supply power and read force responses from the force sensor <NUM>, while allowing the internal wires and electronics to be protected from the outside environment. Additionally, the hermetic sealing of the pin block assembly <NUM> and distal plate <NUM> to the substrate <NUM>, as well as the use of glass seals <NUM> within the pin block assembly <NUM>, allows the force sensor <NUM> to withstand harsh environments (e.g., autowashing and autoclaving) so that an adapter assembly <NUM>", such as that shown in <FIG>, can be cleaned and/or sterilized for multiple uses.

Turning to <FIG>, another embodiment of a force sensor <NUM>' is shown. The force sensor <NUM>' is similar to force sensor <NUM>, and therefore will be described with respect to the differences therebetween. The force sensor <NUM>' includes a substrate <NUM>', a distal or first plate <NUM>', and a pin block assembly <NUM>.

The substrate <NUM>' includes a proximal surface 410a and a distal surface 410b'. The distal surface 410b' is substantially planar, and defines a distal or first recess <NUM>' therein. The first recess <NUM>' is defined in one side of a central aperture <NUM>' of the substrate <NUM>', however, it should be understood that a second recess may be defined in the other side of the central aperture <NUM>' in a location symmetrically opposed to the first recess <NUM>'. A through hole <NUM>' extends between a back wall 414a of the first recess <NUM>' and a lateral region 412b of the proximal surface 410a of the substrate <NUM>'. Sensing elements "Se" (see e.g., <FIG>) are secured within the first recess <NUM>' and the distal plate <NUM>' is secured (e.g., welded) to the distal surface 410b' of the substrate <NUM>' around the entire outer perimeter "Po" of the distal plate <NUM>' to form a hermetic seal to protect the sensing elements and associated components from the external environment. Wires (not shown) that are soldered to the sensing elements, are passed through the through hole <NUM>' and secured to conductive pins <NUM> of the pin block assembly <NUM>, as described above.

In embodiments in which more elongation (e.g., flex) is desired, the substrate of the force sensors <NUM>, <NUM>', <NUM>, <NUM>, <NUM>, <NUM>' may include one or more relief features to facilitate bending or to reduce stiffness. As shown, for example, in <FIG>, a series of relief cuts <NUM> are formed in the substrate <NUM>' of the force sensor <NUM>' adjacent the lateral region 412b and the intermediate region 412c of the stepped proximal surface 410a. As another example, as shown in <FIG>, a hole <NUM> is defined in a top surface 410e' of the substrate <NUM>' of the force sensor <NUM>'. The relief cuts <NUM> and/or holes <NUM> may be formed in a variety of sizes and shapes, such as, but not limited to circular, square, elliptical, trapezoidal, etc., and may be symmetrically positioned about the substrate.

As shown in <FIG>, the force sensor <NUM>', which includes a plurality of relief features or holes 460a-460c defined in the substrate <NUM>', is electrically coupled to a sensor flex cable "F1" via the plurality of conductive pins <NUM> of the pin block assembly <NUM>. As specifically shown in <FIG>, the sensor flex cable "F1" includes solder pads "S1" which are aligned and soldered to solder pads "S2" of an adapter flex cable "F2", the connection of which may be coated with a conformal coating, such as HUMISEAL® UV-<NUM> which is a registered trademark owned by Columbia Chase Corporation, or a flexible resin, such as DOLPHON® CB-<NUM> PBT which is a registered trademark owned by John C. Dolph Company. The adapter flex cable "F2" extends distally to an electrical connector "C" (see e.g., <FIG>) for electrical connection with an end effector <NUM> (<FIG>), and also extends proximally to an electrical connector (not shown) for electrical connection with the powered handle assembly <NUM> (<FIG>).

While the sensor flex cable "F1" is shown coupled to and extending from the proximal surface 410a of the force sensor <NUM>', it should be understood that the sensor flex cable "F1" may be coupled to a distal surface of a force sensor in embodiments in which a through hole extends through the distal surface, as shown, for example, in <FIG>. It is contemplated that through hole(s) utilized for electrically connecting the sensing elements of the force sensor with the electronics of the surgical device may extend through either the proximal or distal surfaces of the force sensor described herein.

Referring now to <FIG>, a force sensor <NUM> in accordance with yet another embodiment is shown. The force sensor <NUM> includes a substrate <NUM>, a first plate set <NUM>, and a second plate <NUM> bonded to the substrate <NUM> in a fluid tight manner. A central aperture <NUM> is defined through the substrate <NUM> and extends along a central longitudinal axis "X" of the substrate <NUM>. The substrate <NUM> includes a proximal surface 510a having central and lateral regions 512a, 512b, and a distal surface 510b having a distally extending flange <NUM> extending around the central aperture <NUM> of the substrate <NUM>. The proximal and distal surfaces 510a, 510b are load bearing surfaces, as described above with regard to force sensor <NUM>, that allow the substrate <NUM> to flex when loaded by the surgical device <NUM> (<FIG>).

The distal surface 510b includes a distal recess <NUM> defined therein. The distal recess <NUM> is a stepped recess including proximal recess portions 511a disposed on opposed sides of the central aperture <NUM> and a distal recess portion 511b. Proximal recessed lips 518a are defined between the proximal and distal recess portions 511a, 511b, and a distal recessed lip 518b is defined between the distal recess portion 511b and the distal surface 510b. Sensing elements "Se" (see e.g., <FIG>) are positioned in at least one of the proximal recess portions 511a and the first plate set <NUM> is disposed over the proximal recess portions 511a in abutting relation with the proximal recessed lips 518a and secured thereto (e.g., by welding). In embodiments, additional clearance may be provided between the proximal recess portions 511a to allow for tracing wires to extend between the proximal recess portions 511a. Each plate of the first plate set <NUM> includes a cut-out <NUM> defined therethrough that is open for the passage of wires (not shown) therethrough. In embodiments, the cut-out <NUM> is disposed in an outer perimeter of each plate of the first plate set <NUM>, however, it should be understood that the cut-out <NUM> may be defined in any portion of the plates of the first plate set <NUM>.

Additional electronic components may be placed on the distal facing surfaces of the plates of the first plate set <NUM>, and the second plate <NUM> is positioned over the distal recess portion 511b in abutting relation with the distal recessed lip 518b so that it is flush with the distal surface 510b of the substrate <NUM>. The second plate <NUM> is secured thereto (e.g., by welding around the entirety of an outer perimeter "Po" and an inner perimeter "Pi" of the second plate <NUM>) to form a hermetic seal to protect the sensing elements "Se" and associated components from the external environment. While the second plate <NUM> is shown and described as being received within the distal recessed lip 518b, it should be understood that the second plate <NUM> may be mounted to the distal surface 510b as shown and described, for example, with respect to the second plate <NUM> of the force sensor <NUM>. The second plate <NUM> includes a through hole <NUM> disposed therethrough to allow for the passage of wires and/or cables (not shown) therethrough. The through hole <NUM> may include a sealant (not shown) to form a seal, as described above, for example, with respect to the through hole <NUM> of substrate <NUM>.

Referring now to <FIG>, a force sensor <NUM> is shown in accordance with yet another embodiment of the present disclosure. The force sensor <NUM> includes a substrate <NUM> having a central aperture <NUM> extending therethrough along a central longitudinal axis "X," and a cap or plate <NUM> configured to mate with substrate <NUM>. The substrate <NUM> includes a proximal surface 610a, a distal surface 610b, a first side surface 610c, a second side surface 610d, a top surface 610e, and a bottom surface 610f. The proximal surface 610a includes central and lateral regions 612a, 612b that are substantially identical to, for example, the proximal surface 110a of force sensor <NUM>. Load bearing tabs <NUM> extend distally from opposed sides of the distal surface 610b which may include lines of contact which act as distal load contact areas "Cd. " In embodiments, the load bearing tabs <NUM> are full radius load bearing tabs, and in some embodiments, the load bearing tabs <NUM> are linear tabs with a full radius of contact. The longitudinal length of the load bearing tabs <NUM> may vary, for example, to increase the thickness of the substrate <NUM> to increase the strength of the force sensor <NUM>.

The substrate <NUM> includes a single continuous recess <NUM> defined in at least two surfaces of the substrate <NUM>, and in embodiments, in at least three surfaces of the substrate <NUM>. As shown, the recess <NUM> is defined in the distal surface 610b, the top surface 610e, and the bottom surface 610f of the substrate <NUM>. The recess <NUM> provides increased surface area for bonding of sensing elements "Se" thereto. In embodiments, the increased surface area allows the sensing elements "Se" to be placed on smaller substrates. As specifically shown in <FIG>, the recess <NUM> include a substantially planar back wall 614a and angled top and bottom walls 614b, 614c that taper proximally. It should be understood that the walls of the recess may be angled or planar depending on the desired characteristics of the force sensor <NUM>.

The cap <NUM> is configured and dimensioned to cover the recess <NUM>. As shown, the cap <NUM> includes a back side 620a corresponding with the distal surface 610b of the substrate, a top side 620b corresponding with the top surface 610e of the substrate <NUM>, and a bottom side 620c corresponding with the bottom surface 610f of the substrate <NUM>. The cap <NUM> is positioned on the substrate <NUM> such that the sides thereof match the surfaces of the substrate <NUM> and lie flush therewith. As shown, the back side 620a lies flush with the distal surfaces 610b of the substrate <NUM>, the top side 620b lies flush with the top surface 610e of the substrate <NUM>, and the bottom side 620c lies flush with the bottom surface 610f of the substrate <NUM>. The cap <NUM> is sealed to the substrate <NUM> in a fluid tight manner by, for example, welding the cap <NUM> around an entire outer perimeter "Po" and an entire inner perimeter "Pi" of the cap <NUM> to the substrate <NUM>. A through hole (not shown) may be provided in the cap <NUM>, in a similar manner as through hole <NUM> of force sensor <NUM>, or through the substrate <NUM> in a similar manner as through hole <NUM> of force sensor <NUM>, for example.

The surgical device is used, for example, in an anastomosis procedure to effect joining of two tubular or hollow tissue sections (e.g., intestinal section) together. Generally, referring again to <FIG>, the anvil assembly <NUM> may be applied to the operative site either through a surgical incision or transanally and positioned within a first intestinal section (not shown) and secured temporarily thereto (e.g., by a purse string suture), and the loading unit <NUM> and outer sleeve <NUM> of the adapter assembly <NUM> may be inserted transanally into a second intestinal section (not shown) and secured temporarily thereto. Thereafter, a clinician maneuvers the anvil assembly <NUM> until the proximal end of the anvil rod 34b is inserted into the distal end of the adapter assembly <NUM>, wherein mounting structure (not shown) within the distal end of adapter assembly <NUM> engages anvil rod 34b to effect mounting. The anvil assembly <NUM> and the loading unit <NUM> are then approximated to approximate the first and second intestinal sections. Surgical device <NUM> is then fired, and a knife (not shown) cuts the portion of tissue disposed radially inward of the knife, to complete the anastomosis.

The force sensors of the present disclosure may be utilized to enhance the anastomosis procedure by controlling a function of the surgical device. For example, the force sensor may be used to control the force and/or rate of compression of tissue. If tissue is compressed too rapidly, it may become bruised, torn, damaged, etc. during such compression. Without being bound to any particular theory, it is believed that maintaining a constant force of compression on the tissue of, for example, around <NUM> pounds, provides a steady yet rapid compression of tissue until the optimal staple gap is achieved for performing stapling and cutting functions. The force sensors may be utilized to first read the force to compress the tissue. Once compressed, the force sensor may also monitor the stapling function. Such monitoring allows for the programming of the stapling function. In embodiments, the surgical device is programmed to deliver a preset load depending on the anvil selected. For example, a smaller anvil, e.g., a <NUM> anvil, requires a lower force than a larger anvil, e.g., a <NUM> anvil. In embodiments, the cutting function may be controlled to stop at a predetermined force. This allows for the electronics and software to control such functions eliminating the need for tight mechanical stops.

Claim 1:
A force sensor (<NUM>, <NUM>', <NUM>, <NUM>, <NUM>, <NUM>', <NUM>, <NUM>) for use in a powered surgical device, the force sensor comprising:
a substrate (<NUM>, <NUM>', <NUM>, <NUM>, <NUM>, <NUM>', <NUM>, <NUM>) including a central aperture (<NUM>, <NUM>, <NUM>, <NUM>) extending along a longitudinal axis of the substrate, the substrate having a proximal surface, a distal surface, a first side surface, a second side surface, a top surface, and a bottom surface, at least one of the distal surface, the first side surface, the second side surface, the top surface, or the bottom surface including a recess (<NUM>, <NUM>, <NUM>', <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>', <NUM>, <NUM>) defined therein;
a plurality of sensing elements (Se) disposed within the recess; and
a plate (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>', <NUM>, <NUM>, <NUM>) disposed over the recess and mounted to the substrate to hermetically seal the plurality of sensing elements within the substrate, whereby the force sensor is sealed and configured to withstand environmental stresses associated with cleaning and sterilization.