Patent Description:
Force sensors (e.g., load reading sensors) have been used to enhance control of functions in a surgical device, such as a surgical stapling instrument. By using a force sensor, the clamping, stapling, and cutting forces of the surgical device can be monitored and used to facilitate these various functions. The force sensor can be used to detect pre-set loads and cause the surgical device to react in response thereto. 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> PSI @ <NUM> for <NUM> minutes). Such an environment is known to damage electronic components. For example, surgical devices may suffer from moisture ingress during cleaning and/or sterilizing procedures which, in turn, may corrode and/or degrade the electronic components.

It would be beneficial if the durability of the electronic components of the reusable surgical devices is enhanced to withstand cleaning and sterilization procedures (e.g., the electronic components are protected from high temperatures, steam, and/or moisture), thereby improving the reliability of the electronic components and/or extending the effective cycle life of the surgical device at a cost reduction and with improved manufacturability.

<CIT> discloses a force sensor including a substrate, a plurality of sensing elements and a plate for use in a surgical instrument.

According to the invention, in a first and a second aspect there is provided a force sensor as claimed in the independent claims with preferred features as set forth in the claims depending therefrom. A further aspect of the invention provides a surgical device including a force sensor in accordance with the first aspect.

The force sensors of the present disclosure are sealed to withstand environmental stresses associated with high pH cleaning and sterilization (e.g., autowashing and/or autoclaving), minimizing and/or eliminating the ingress of fluids during such processes thereby rendering the force sensors more durable for re-use.

The force sensors utilize a seal assembly held under mechanical compressive load to protect electronic components of the force sensor. The seal assembly may reduce or eliminate the use of expensive parts and/or intensive processes, such as laser welding, leak testing, and/or molded plastic potting, thereby providing a cost reduction over conventional force sensors. Further, the reduction or elimination of process control needs associated with welding and potting methods improves the design and manufacture of the force sensor and enables disassembly for error correction or salvage of components which improves production yield and reduces scrap. The seal assembly may reduce or eliminate the need for coatings thereby attaining greater reliability cycles.

In one aspect of the present disclosure, a force sensor includes a substrate, sensing elements, a pin block assembly, a first gasket, a flex cable, a second gasket, a retainer plate, and a seal restraint. The substrate has proximal and distal surfaces, and defines a cavity therein that is open to the proximal surface. The sensing elements are disposed within the cavity of the substrate. The pin block assembly is mounted within the cavity of the substrate and electrically coupled to the sensing elements. The first gasket is disposed within the cavity of the substrate over the pin block assembly. The flex cable is positioned against the proximal surface of the substrate over the cavity and is electrically coupled to the pin block assembly. The second gasket is positioned over the flex cable and the retainer plate is positioned over the second gasket. The seal restraint is coupled to the substrate and extends over the retainer plate. The seal restraint applies pressure on the retainer plate and compresses the second gasket against the flex cable to seal the cavity of the substrate.

In aspects, the sensing elements are body bloc.

In aspects, the pin block assembly includes a block body and pins extending through the block body. Each of the pins has a proximal portion and a distal portion extending proximally and distally, respectively, from the block body. The proximal portions of the pins extend proximally out of the cavity of the substrate and the distal portions of the pins are disposed within the cavity. In some aspects, the first gasket defines at least one opening therethrough, and the proximal portions of the pins of the pin block assembly extend proximally through the at least one opening of the first gasket. In some aspects, the flex cable includes a plurality of apertures defined therethrough, and the proximal portions of the pins of the pin block assembly extend proximally through the plurality of apertures. In some aspects, the second gasket defines openings therethrough, and the proximal portions of the pins of the pin block assembly are disposed within the openings of the second gasket.

In some aspects, the flex cable is wrapped over a proximal end of the second gasket, and the retainer plate is positioned against the flex cable.

In aspects, the cavity of the substrate is open to the distal surface, and the force sensor further includes an electronics assembly electrically coupled to the pin block assembly and extending distally out of the cavity. In some aspects, the force sensor further includes a cover disposed over the electronics assembly and positioned against the distal surface of the substrate over the cavity. The seal restraint extends over and compresses the cover against the distal surface to seal the cavity on the distal surface of the substrate. In certain aspects, the seal restraint is a compression clip including a proximal wall engaged with the retainer plate and a distal wall engaged with the cover.

In another aspect of the present disclosure, a surgical device includes a powered handle assembly, an adapter assembly including a distal connector housing and a trocar connection housing, an end effector releasably secured to the distal connector housing of the adapter assembly, and the force sensor described above disposed between the distal connector housing and the trocar connection housing. The force sensor is configured to measure forces exhibited by the end effector along a load path.

In aspects, the flex cable is electrically coupled to the powered handle assembly and the end effector assembly such that the forces measured by the force sensor is communicated to the powered handle assembly to affect a function of the end effector.

In yet another aspect of the present disclosure, a force sensor includes a substrate, sensing elements, a pin block assembly, a first gasket, a flex cable, a second gasket, a retainer plate, and a seal restraint. The substrate has proximal and distal surfaces, and defines a cavity therein open to the proximal surface. The sensing elements are disposed within the cavity of the substrate. The pin block assembly is mounted on the proximal surface of the substrate over the cavity and is electrically coupled to the sensing elements. The first gasket is positioned over the pin block assembly, the flex cable is positioned over the first gasket and electrically coupled to the pin block assembly, the second gasket is positioned over the flex cable, the retainer plate is positioned over the second gasket, and the seal restraint is coupled to the substrate. The seal restraint applies pressure on the retainer plate and compresses the second gasket, the flex cable, the first gasket, and the pin block assembly against the proximal surface of the substrate to seal the cavity of the substrate.

In aspects, the sensing elements are strain gauges.

In some aspects, the pin block assembly includes a block body and pins extending through the block body. Each of the pins has a proximal portion and a distal portion extending proximally and distally, respectively, from the block body. The distal portions of the pins are disposed within the cavity.

In aspects, the proximal surface of the substrate includes holes defined therein, and the seal restraint extends into the holes. In some aspects, each of the first gasket, the flex cable, the second gasket, and the retainer plate define through holes therethrough that are aligned with the holes defined in the substrate. In certain aspects, the seal restraint is screws extending through the through holes of the retainer plate, the second gasket, the flex cable, and the first gasket, and into the holes of the substrate.

In aspects, the cavity of the substrate is open to the distal surface, and the force sensor further includes an electronics assembly electrically coupled to the pin block assembly and extending distally out of the cavity. In some aspects, the force sensor further includes a cover disposed over the electronics assembly and positioned against the distal surface of the substrate to seal the cavity on the distal surface of the substrate.

The details of one or more aspects of this disclosure are set forth in the accompanying drawings and the description below. Other aspects, as well as features, objects, and advantages of the aspects described in this disclosure will be apparent from the description and drawings, and from the claims.

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

The force sensors of the present disclosure of, e.g., surgical devices, include electronic components that are protected from harsh environments, such as autowashing and/or autoclaving. The force sensors include a substrate having sensing elements, such as strain gauges and their supporting electronics, mounted therein, which are covered by a seal assembly to create a protective leak-proof barrier to the sensing elements.

Aspects 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.

Turning now to <FIG>, a surgical device <NUM>, in accordance with an aspect of the present disclosure, is in the form of a powered handheld electromechanical instrument. The surgical device <NUM> includes a powered handle assembly <NUM>, a tool assembly or end effector <NUM>, and an adapter assembly <NUM> interconnecting the powered handle assembly <NUM> and the end effector <NUM>. 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>.

The surgical device <NUM> will further be described to the extent necessary to disclose aspects of the present disclosure. Additionally, while described and shown as including powered handle assembly <NUM>, end effector <NUM>, and adapter assembly <NUM>, it should be understood that a variety of different handle assemblies, end effectors, and/or adapter assemblies may be utilized with aspects of the present disclosure.

With continued reference to <FIG>, the powered 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>. The end effector <NUM> includes a loading unit <NUM> having a plurality of staples (not shown) disposed therein and an anvil assembly <NUM> including an anvil head 24a and an anvil rod 24b. The adapter assembly <NUM> includes a proximal portion 30a configured for operable connection to the handle assembly <NUM> and a distal portion 30b configured for operable connection to the end effector <NUM>.

Referring now to <FIG>, the adapter assembly <NUM> includes an outer sleeve <NUM> and a distal connector housing <NUM> secured to a distal end of the outer sleeve <NUM>. The distal 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> includes a wiring assembly <NUM> (shown in phantom) disposed therein. The wiring assembly <NUM> is configured to enable communication between the handle assembly <NUM> (<FIG>) and the end effector <NUM> (<FIG>) and to relay power from the handle assembly <NUM> to the end effector <NUM>. For example, this communication allows for calibration and communication of data and control signals between the end effector <NUM> and the adapter assembly <NUM>, as well as between the adapter assembly <NUM> and the handle assembly <NUM>, thereby transferring data pertaining to the end effector <NUM> to the handle assembly <NUM> and signals from the handle assembly <NUM> to the end effector <NUM>. The wiring assembly <NUM> includes a force sensor <NUM> that detects stimuli (e.g., strain), converts the stimuli into electrical signals, and sends that data to the handle assembly <NUM> to affect a function of the end effector <NUM>. It should be understood while described and shown as a force sensor and, more specifically, as a strain gauge, other types of sensors may additionally or alternatively be utilized in the anvil assembly <NUM>.

The wiring assembly <NUM> generally includes at least one flex cable <NUM>, as well as first and second electrical connectors <NUM>, <NUM> and the force sensor <NUM> coupled to the flex cable <NUM>. The flex cable <NUM> extends the length of the adapter assembly <NUM> and includes electrical contact regions (not shown) at terminal ends of conductive traces (not shown) defined therethrough for electrical connection with the first and second electrical connectors <NUM>, <NUM> and the force sensor <NUM>. The flex cable <NUM> includes a first or proximal end portion 42a coupled to the first electrical connector <NUM> for electrical connection with the handle assembly <NUM> (<FIG>), a second or distal end portion 42b coupled to the second electrical connector <NUM> for electrical connection with the end effector <NUM> (<FIG>), and a third or intermediate end portion 42c electrically coupled to the force sensor <NUM>. In aspects, the flex cable <NUM> supports electronic components thereon (e.g., surface mount technology and/or through-hole technology, including, for example, integrated circuits (e.g., microchips, microcontrollers, microprocessors), resistors, amplifiers, inductors, capacitors, sensing elements (e.g., optical sensors, pressure sensors, capacitive sensors), buttons, switches, circuit boards, electrical connectors, cables, and/or wires, among other elements or circuitry within the purview of those skilled in the art). It should be understood that the flex cable <NUM> may be one of a plurality of cables (e.g., flex cables, adapter cables, etc.) electrically coupled together to form a wiring harness, as is within the purview of those skilled in the art.

As shown in <FIG>, the adapter assembly <NUM> further includes a trocar assembly <NUM> that extends through a central aperture <NUM> (see e.g., <FIG>) of the 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>. The force sensor <NUM> is disposed between the trocar connection housing <NUM> and the distal connector housing <NUM> of the adapter assembly <NUM>, and is configured to measure forces along a load path. Specifically, the force sensor <NUM> measures forces of the end effector <NUM> (e.g., as shown in <FIG>, the pressure applied by the anvil head 24a in the direction of arrow "A" against the distal portion 30b of the adapter assembly <NUM>, the pressure applied by tissue acting on the anvil head 24a in a direction opposite of arrow "A" as the anvil head 24a is closed onto tissue, etc.).

As shown in <FIG> and <FIG>, the trocar connection housing <NUM> includes a distal surface 38a 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 34a of the distal connector housing <NUM> interfaces with and loads a distal surface 110b of the substrate <NUM> of the force sensor <NUM> at distal load contact areas "Cd" (e.g., disposed in each of the corners of the distal surface 110b). Thus, for example, as the anvil assembly <NUM> (<FIG>) is approximated towards the loading unit <NUM> (<FIG>) of the end effector <NUM> during clamping and/or stapling of tissue, the anvil head 24a applies uniform pressure in the direction of arrow "A" (<FIG>) against the distal end 34b of the distal connector housing <NUM> which, in turn, is transmitted to the distal load contact areas "Cd" of the force sensor <NUM>.

As shown in <FIG>, the substrate <NUM> of the force sensor <NUM> has a central aperture <NUM> defined through the proximal and distal surfaces 110a, 110b and extending along a central longitudinal axis "X" of the substrate <NUM>. The substrate <NUM> is divided into first and second lateral halves 111a, 111b by a plane passing through the central longitudinal axis "X". The proximal surface 110a (<FIG>) and the distal surface 110b (<FIG>) of the substrate <NUM> are load bearing surfaces having proximal and distal load contact areas "Cp," "Cd," respectively, as described above, that allow the substrate <NUM> to compress when loaded by the surgical device <NUM> (<FIG>). The substrate <NUM> is formed from a rigid material having high strength and high temperature endurance, such as a metal (e.g., stainless steel).

As seen in <FIG>, the proximal surface 110a of the substrate <NUM> is a stepped surface including a central wall 112a, lateral walls 112b, and intermediate walls 112c interconnecting the central and lateral walls 112a, 112b. The central wall 112a is substantially planar and extends along a plane lying substantially perpendicular to the central longitudinal axis "X" of the substrate <NUM>, and the lateral walls 112b 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 relative to the central wall 112a. The intermediate walls 112c 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 110a may have other configurations, such as, for example, angled lateral walls. As seen in <FIG>, the distal surface 110b of the substrate <NUM> is substantially planar and extends along a plane lying substantially perpendicular to the central longitudinal axis "X" (<FIG>) of the substrate <NUM> and substantially parallel to the central and lateral walls 112a, 112b (<FIG>) of the proximal surface 110a.

Turning now to <FIG> and <FIG>, the force sensor <NUM> generally includes the substrate <NUM>, sensing elements <NUM>, a pin block assembly <NUM>, an electronics assembly <NUM>, and a seal assembly <NUM>. The substrate <NUM> includes a cavity <NUM> defined in the first lateral half 111a that is open at both the proximal and distal surfaces 110a, 110b. The distal surface 110a further includes a groove <NUM> (<FIG>) recessed therein that extends around the opening into the cavity <NUM> for engagement with a cover <NUM> of the seal assembly <NUM>.

In aspects, the substrate <NUM> includes relief holes <NUM> defined in a top surface 110c thereof to facilitate bending and/or to reduce stiffness of the substrate <NUM>. It should be understood that the relief holes <NUM>, as well as other relief features, such as relief cuts, may be formed in the substrate <NUM> in a variety of shapes and sizes, as well as in different positions about the substrate <NUM> when more elongation (e.g., flex) is desired.

The sensing elements <NUM>, for example, strain gauges, are disposed within the cavity <NUM> of the substrate <NUM> and bonded (e.g., glued) to the substrate <NUM> (see e.g., <FIG>) along with associated components thereof (not shown), e.g., media layers, films, protective coatings, circuitry including electronic components, such as resistors, conductive wires and/or traces, and electronic and/or solder connectors, etc. The sensing elements <NUM> 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. Alternatively, the sensing elements <NUM> may be directly coated or etched onto the substrate <NUM> by, for example, vapor deposition. In some aspects, the substrate <NUM> includes a thin insulative layer (e.g., vapor deposited glass) and a thin conductive layer (e.g., nichrome) laser etched to include the sensing elements <NUM> and the Wheatstone bridge.

The pin block assembly <NUM> is fixedly secured within the cavity <NUM> of the substrate <NUM>. The pin block assembly <NUM> includes a block body <NUM> and a plurality of pins <NUM> (referred to herein generally as pins) extending through the block body <NUM> in spaced relation relative to each other. The block body <NUM> is formed from an insulative material, such as glass or plastic, and the pins <NUM> are formed from a conductive material, such as metal. Each of the pins <NUM> includes a proximal portion 134a and a distal portion 134b extending proximally and distally, respectively, from the block body <NUM>. The sensing elements <NUM> are electrically coupled to the pins <NUM>, for example, by wires (not shown), within the cavity <NUM> of the substrate <NUM>. The proximal portions 134a of the pins <NUM> extend beyond the proximal surface 110a of the substrate <NUM> for electrical connection with the flex cable <NUM>, and the distal portions 134b of the pins <NUM> are disposed within the cavity <NUM> for electrical connection within the electronics assembly <NUM>.

The electronic assembly <NUM> includes a circuit board <NUM> and a connector <NUM> for electrical connection with the distal portions 134b of the pins <NUM> of the pin block assembly <NUM>. The connector <NUM> is disposed within the cavity <NUM> of the substrate <NUM> and the circuit board <NUM> extending distally out of the cavity <NUM> beyond the distal surface 110b of the substrate <NUM>. The circuit board <NUM> is configured for reading and/or storing data pertaining to the force sensor <NUM> and sending the data to the powered handle assembly <NUM> (<FIG>) via the flex cable <NUM>. The circuit board <NUM> includes a microprocessor 142a and a memory 142b. The microprocessor 142a is configured to receive and/or measure electrical signals from the sensing elements <NUM> and record them in the memory 142b which, in turn, is configured to store the data received from the microprocessor 142a. The memory 142b is configured to communicate the data to the handle assembly <NUM> (<FIG>) via electrical contact with the pin block assembly <NUM> and the flex cable <NUM> which, in turn, is electrically coupled to the handle assembly <NUM> by the first electrical connector <NUM> (<FIG>). The data may be processed by a processor of the power-pack (not shown) of the powered handle assembly <NUM> (<FIG>) or in some remote processor or the like. The data may include, for example, stress measurements along the anvil assembly <NUM> (<FIG>) which are converted via an algorithm into corresponding tissue stress measurements. It should be understood that the data may correspond with other desired monitored properties of the end effector <NUM> (<FIG>) which, in turn, correspond with other desired monitored tissue properties and/or behaviors depending upon the type of sensing elements <NUM> and/or sensor utilized in the anvil assembly <NUM>.

The seal assembly <NUM> secures the flex cable <NUM> to the substrate <NUM> and seals the cavity <NUM> of the substrate <NUM> to protect the sensing elements <NUM>, the pin block assembly <NUM>, and the electronics assembly <NUM> disposed therein. The seal assembly <NUM> includes first and second gaskets <NUM>, <NUM>, a retainer plate <NUM>, a cover <NUM>, and a seal restraint <NUM>. The first or header gasket <NUM> is sized and shaped for positioning within the cavity <NUM> between the block body <NUM> of the pin block assembly <NUM> and the proximal surface 110a of the substrate <NUM>. The first gasket <NUM> includes a gasket body 152a defining an opening <NUM> therethrough. The gasket body 152a is configured to abut the block body <NUM> and to be flush with the proximal surface 110a of the substrate <NUM> such that the proximal portions 134a of the pins <NUM> of the pin block assembly <NUM> extend through the opening <NUM> defined in the gasket body 152a and proximally beyond the proximal surface 110a of the substrate <NUM>. The opening <NUM> of the first gasket <NUM> may be a single, continuous opening or include a plurality of openings aligned or in registration with the pins <NUM>. The first gasket <NUM> is formed from a high temperature compliant material, such as an elastomeric material (e.g., silicone, rubber, or combinations thereof, such as those sold under the trademark Elastosil® of Wacker Chemie AG) to aid in sealing the opening into the cavity <NUM> of the substrate <NUM>.

The third portion 42c of the flex cable <NUM> is sized and shaped for positioning over the cavity <NUM> on the proximal surface 110a of the substrate <NUM> and is dimensioned to be larger in size than the opening into the cavity <NUM> such that the flex cable <NUM> lays substantially flush against the proximal surface 110a of the substrate <NUM> and the first gasket <NUM> is disposed within the cavity <NUM>. The third portion 42c of the flex cable <NUM> includes a plurality of apertures <NUM> defined therethrough that are sized, shaped, and positioned to receive the pins <NUM> of the pin block assembly <NUM> therethrough. The third portion 42c of the flex cable <NUM> is positioned over the first gasket <NUM> of the seal assembly <NUM> such that the proximal portions 134a of the pins <NUM> of the pin block assembly <NUM> engage and extend through the plurality of apertures <NUM> of the flex cable <NUM>.

The second gasket <NUM> is sized and shaped for positioning over the third portion 42c of the flex cable <NUM>. The second gasket <NUM> includes a gasket body 154a defining a plurality of openings <NUM> therethrough that are aligned or in registration with the pins <NUM> of the pin block assembly <NUM>. The second gasket <NUM> is positioned over the third portion 42c of the flex cable <NUM> such that the proximal portions 134a of the pins <NUM> extend into and are disposed within the plurality of openings <NUM> of the second gasket <NUM>, as seen in <FIG>. The second gasket <NUM> is formed from a high temperature compliant material, such as an elastomeric material (e.g., the same as or similar to the first gasket <NUM>), that is compressible against the pins <NUM> and the flex cable <NUM> to aid in sealing the opening into the cavity <NUM> of the substrate <NUM>. In some aspects, the second gasket <NUM> is formed from a more flexible material than the first gasket <NUM>. In aspects in which the third portion 42c of the flex cable is defined in an end of the flex cable <NUM>, the flex cable <NUM> is wrapped around the second gasket <NUM>, as seen, for example, in <FIG>, such that the second gasket <NUM> is sandwiched between the flex cable <NUM>.

The retainer plate <NUM> is sized and shaped for positioning against the flex cable <NUM>. The retainer plate <NUM> includes a flat body 156a having a lip 156b extending around a distal end of the flat body 156a. The retainer plate <NUM> is positioned against the flex cable <NUM> to mechanically compress the second gasket <NUM> towards the proximal surface 110a of the substrate <NUM>. The retainer plate <NUM> is formed from a rigid material that is non-toxic, chemically inert, and capable of withstanding high temperatures and harsh detergents, such as, for example, a metal (e.g., stainless steel) or a polymer (e.g., polyphenylsulfone, such as those sold under the trademark Radel® by Solvay Specialty Polymers USA, L.

Alternatively, the retainer plate <NUM> may define a cavity (not shown) therein that is configured to receive the flex cable <NUM> and the second gasket <NUM> therein. In such aspects, the lip 156b of the retainer plate <NUM> abuts the proximal surface 110a of the substrate <NUM> as well as the portion of the flex cable <NUM> extending outwardly therefrom, thereby compressing the second gasket <NUM> within the retainer plate <NUM>.

The cover <NUM> is sized and shaped to house the circuit board <NUM> of the electronics assembly <NUM> therein. The cover <NUM> includes an elongated body 158a having an open proximal end 158b and a closed distal end 158c thereby defining a pocket <NUM> therein. A flange 158d extends around an entire outer perimeter of the open proximal end 158b for engagement with the distal surface 110b of the substrate <NUM> and, more specifically, for positioning within the groove <NUM> defined in the distal surface 110b. In some aspects, at least the flange 158d of the cover <NUM> and, in certain aspects, the entire cover <NUM> is formed from a polymeric material, such as an elastomer having a low durometer, to effectively seal the distal surface 110b of the substrate <NUM> over which the cover <NUM> is disposed in a fluid tight manner by a relatively low closure force provided by the seal restraint <NUM> of the seal assembly <NUM>. In aspects, the cover <NUM> is fabricated from a rigid material (e.g., the same as or similar to the retainer plate <NUM>).

Alternatively, in some aspects, the electronics assembly <NUM> may be integrated into the flex cable <NUM> and the cavity <NUM> of the substrate <NUM> is only open to the proximal surface 110a of the substrate <NUM>. In such aspects, the force sensor <NUM> does not include the electronics assembly <NUM> or the cover <NUM> of the seal assembly <NUM>.

The seal restraint <NUM> is in the form of a compression clip, and is sized and shaped for positioning around the first lateral half 111a of the substrate <NUM> to secure the seal assembly <NUM> to the substrate <NUM>. The compression clip <NUM> includes a side wall <NUM> configured to extend along a side surface 110d of the substrate <NUM>. In aspects, the side wall <NUM> of the compression clip <NUM> is positioned within a recess <NUM> defined in the side surface 110d of the substrate <NUM> such that the compression clip <NUM> is flush with the side surface 110d. The compression clip <NUM> further includes a proximal wall <NUM> extending transversely from the side wall <NUM> at a first or proximal end 162a thereof for engaging (e.g., covering) the retainer plate <NUM> and securing the first and second gaskets <NUM>, <NUM> as well as the third portion 42c of the flex cable <NUM> to the proximal surface <NUM> of the substrate <NUM>, and a distal wall <NUM> extending transversely from the side wall <NUM> at a second or distal end 162b thereof for engaging and securing the cover <NUM>, and more specifically, the flange 158d, to the distal surface 110b of the substrate <NUM>. While the distal wall <NUM> is shown as being bifurcated, the distal wall <NUM> may be a continuous wall defining an opening therethrough that is configured to receive the cover <NUM> therethrough and press the flange 158d against the distal surface 110b of the substrate <NUM>.

The compression clip <NUM> mechanically compresses the seal assembly <NUM> against the substrate <NUM> to hermetically seal the sensing elements <NUM>, the pin block assembly <NUM>, and the electronics assembly <NUM> within the cavity <NUM> of the substrate <NUM>. The compression clip <NUM> applies a constant pressure onto the components of the seal assembly <NUM> to prevent the ingress of fluids (e.g., liquids) during a cleaning or sterilization cycle thereby protecting the electronic components from the external environment. Specifically, the compression clip <NUM> applies pressure onto the retainer plate <NUM> towards the proximal surface 110a of the substrate <NUM> which, in turn, applies pressure onto the second gasket <NUM> and the flex cable <NUM> such that the second gasket <NUM> and flex cable <NUM> is compressed against the proximal surface 110a of the substrate <NUM> to close the opening into the cavity <NUM> on the proximal side of the substrate <NUM>. The compression clip <NUM> also applies pressure and compresses the flange 158d of the cover <NUM> towards and against the distal surface 110b of the substrate <NUM> to close the opening into the cavity <NUM> on the distal side of the substrate <NUM>. Accordingly, the compression clip <NUM> is held in place by the spring force from the compressed first and second gaskets <NUM>, <NUM> and flange 158d. In some aspects, the cover <NUM> of the seal assembly <NUM> may be additionally secured to the substrate <NUM> by conventional methods, such as the use of adhesives or coatings, among other techniques within the purview of those skilled in the art. The compression clip is fabricated from a rigid material, such as metal or plastic.

Turning now to <FIG>, a force sensor <NUM> in accordance with another aspect of the present disclosure is shown for use in the surgical device <NUM> (<FIG>). The force sensor <NUM> generally includes a substrate <NUM>, sensing elements <NUM>, a pin block assembly <NUM>, an electronics assembly <NUM>, and a seal assembly <NUM>. The force sensor <NUM> is electrically coupled to a flex cable <NUM>', as described above with regard to force sensor <NUM>. The force sensor <NUM> and the flex cable <NUM>' are substantially similar to the force sensor <NUM> and the flex cable <NUM> of <FIG> and will be described with respect to the differences therebetween. Accordingly, it should be understood that various components of the disclosure, such as those numbered in the <NUM> series or plainly numbered, correspond to components of the disclosure similarly numbered in the <NUM> series or prime numbered, such that redundant explanation of similar components need not be repeated herein.

The substrate <NUM> is substantially the same as the substrate <NUM> (<FIG>) of the force sensor <NUM>, except that the proximal surface 210a further includes a groove <NUM> recessed therein that extends around the opening into the cavity <NUM> for engagement with the pin block assembly <NUM>. Holes <NUM> are defined through the proximal surface 210a and on opposed sides of the cavity <NUM> within the groove <NUM>. In aspects, the holes <NUM> are threaded for engagement with a seal restraint <NUM> of the seal assembly <NUM>.

The pin block assembly <NUM> includes a block body <NUM> and a plurality of pins <NUM> extending through the block body <NUM>. The block body <NUM> further includes through holes <NUM> extending therethrough on opposed sides of the pins <NUM> that are aligned or in registration with the holes <NUM> of the substrate <NUM>.

The seal assembly <NUM> includes first and second gaskets <NUM>, <NUM>, a retainer plate <NUM>, a cover <NUM>, and a seal restraint <NUM>. Each of the first and second gaskets <NUM>, <NUM> includes a gasket body 252a, 254a defining a plurality of openings <NUM>, <NUM> therethrough that are aligned or in registration with the pins <NUM> of the pin block assembly <NUM>, and further includes through holes 253a, 255a that are aligned or in registration with the through holes <NUM> of the pin block assembly <NUM>. The first and second gaskets <NUM>, <NUM> are formed from a flexible material, such as an elastomeric material (e.g., silicone rubber) that have sealing and adhesive properties and durability. The retainer plate <NUM> includes a flat body 256a defining through holes <NUM> therethrough aligned or in registration with the through holes <NUM> of the pin block assembly <NUM>.

The flex cable <NUM>' is substantially the same as flex cable <NUM> (<FIG>), except that the third portion 42c' of the flex cable <NUM>', in addition to including the plurality of apertures <NUM>' that are sized, shaped, and positioned to receive the pins <NUM> of the pin block assembly <NUM> therethrough, includes through holes <NUM>' that are sized, shaped, and positioned to receive the seal restraint <NUM> therethrough.

The seal restraint <NUM> is in the form of screws, with each screw <NUM> including a head 266a and a threaded shank 266b extending from the head 266a. The screws <NUM> are sized and shaped for positioning through the through holes 253a, 255a of the first and second gaskets <NUM>, <NUM>, the through holes <NUM> of the pin block assembly <NUM>, the through holes <NUM>' of the flex cable <NUM>', and into the holes <NUM> of the substrate <NUM>.

A method of assembling the seal assembly <NUM> onto the force sensor <NUM> is shown in <FIG>. With the sensing elements <NUM> (<FIG>) positioned and secured to the substrate <NUM> within the cavity <NUM>, the pin block assembly <NUM> is positioned on the first lateral half 211a of the proximal surface 210a of the substrate <NUM> such that distal portions 234b (<FIG>) of the pin <NUM> are disposed within the cavity <NUM> of the substrate <NUM> and the block body <NUM> is positioned adjacent to the proximal surface 210a of the substrate <NUM> and seated within the groove <NUM>, as seen in <FIG>. The sensing elements <NUM> (<FIG>) are electrically coupled to the distal portions 234b (<FIG>) of the pins <NUM> via, e.g., wires (not shown), as described above and the connector <NUM> (<FIG>) of the electronics assembly <NUM> is positioned within the cavity <NUM> of the substrate <NUM> and coupled to the distal portions 234b of the plurality of pins <NUM> via, e.g., wires (not shown) for electrical connection with the circuit board <NUM>, which extends distally out of the substrate <NUM>. The cover <NUM> is positioned over the electronics assembly <NUM> (<FIG>) and secured to the distal surface 210b of the substrate <NUM>, e.g., by welding, adhesives, coatings, and/or mechanical connections (e.g., the same as or similar to the seal restraint <NUM>, <NUM>) to seal the cavity <NUM> on the distal side of the substrate <NUM>.

As shown in <FIG>, the first gasket <NUM> is then placed atop the block body <NUM> of the pin block assembly <NUM> with the proximal portions 234a of the pins <NUM> extending through the openings <NUM> of the first gasket <NUM> and the through holes 253a aligned with the through holes <NUM> (<FIG>) of the block body <NUM> such that the first gasket <NUM> lays flush against the block body <NUM>.

As seen in <FIG>, the third portion 42c' of the flex cable <NUM>' is then positioned over the first gasket <NUM> such that the proximal portions 234a of the pins <NUM> of the pin block assembly <NUM> extend through the plurality of apertures <NUM>' of the flex cable <NUM>' and the through holes <NUM> are aligned with the through holes 253a (<FIG>) of the first gasket <NUM> such that the third portion 42c' of the flex cable <NUM>' lays flush against the first gasket <NUM>.

As seen in <FIG>, the second gasket <NUM> is positioned over the third portion 42c' of the flex cable <NUM>' such that the proximal portions 234a of the pins <NUM> extend into and are disposed within the plurality of openings <NUM> of the second gasket <NUM> and the through holes 255a are aligned with the through holes <NUM> (<FIG>) of the flex cable <NUM>'. The second gasket <NUM> lays flush against the flex cable <NUM>'.

As seen in <FIG>, the retainer plate <NUM> is positioned over the second gasket <NUM> with the through holes <NUM> aligned with the through holes 255a (<FIG>) of the second gasket <NUM>. As seen in <FIG>, in conjunction with <FIG>, the threaded shanks 266b of the screws <NUM> are then inserted through the through holes <NUM> of the retainer plate <NUM>, the through holes 255a of the second gasket <NUM>, the through holes <NUM>' of the flex cable <NUM>', the through holes 253a of the first gasket <NUM>, and into the holes <NUM> of the substrate <NUM>, and the heads 266a of the screws <NUM> are seated within the retainer plate <NUM>.

The screws <NUM> secure the pin block assembly <NUM>, the first and second gaskets <NUM>, <NUM>, the flex cable <NUM>', and the retainer plate <NUM> to the substrate <NUM> and applies pressure onto the retainer plate <NUM> to compress the first and second gaskets <NUM>, <NUM> between the retainer plate <NUM> and the block body <NUM> of the pin block assembly <NUM>. The screws <NUM> apply constant pressure on the components of the seal assembly <NUM> to effective seal the electronic components therein.

While the force sensors <NUM>, <NUM> are shown including sensing elements and a seal assembly associated with the first lateral half of the substrate, it should be understood that additionally or alternatively, the force sensors <NUM>, <NUM> may include a cavity in the second lateral half of the substrate. At least because the first and second lateral halves of the substrate are mirror images of each other, a person of ordinary skill in the art will readily understand that the seal assemblies are configured to accommodate such alternate or additional configurations. In aspects in which the sensing elements are disposed in each of the first and second lateral halves of the substrate, two seal assemblies would be utilized with the force sensor, as can be readily appreciated by one skilled in the art.

It should be understood that the seal assembly may vary. For example, additional gaskets may be provided and/or alternate seal restraints may be utilized used to hold the seal assembly under compressive load. Accordingly, while the seal restraints are shown as a compression clip and as screws, other configurations are envisioned (e.g., straps).

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 natural orifice (e.g., transanally) and positioned within a first tissue or intestinal section (not shown) and secured temporarily thereto (e.g., by a purse string suture), and the loading unit <NUM> and the outer sleeve <NUM> (<FIG>) of the adapter assembly <NUM> may be inserted into a second tissue or intestinal section (not shown) and secured temporarily thereto. Thereafter, a clinician maneuvers the anvil assembly <NUM> until the proximal end of the anvil rod 24b is inserted into the distal end of the adapter assembly <NUM>, wherein mounting structure (not shown) within the distal end of the adapter assembly <NUM> engages the anvil rod 24b to effect mounting. The anvil assembly <NUM> and the loading unit <NUM> are then approximated to approximate the first and second tissue sections. The 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 <NUM>, <NUM> of the present disclosure may be utilized to enhance the anastomosis procedure by controlling a function of the surgical device <NUM>. For example, the force sensors 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 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 sensors may also monitor the stapling function. Such monitoring allows for the programming of the stapling function. In aspects, the surgical device is programmed to deliver a preset load depending on the anvil selected. For example, a smaller anvil requires a lower force than a larger anvil. In aspects, 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>) comprising:
a substrate (<NUM>; <NUM>) having a proximal surface and a distal surface, the substrate defining a cavity (<NUM>;<NUM>) therein open to the proximal surface;
sensing elements (<NUM>) disposed within the cavity of the substrate;
a pin block assembly (<NUM>; <NUM>) mounted within the cavity of the substrate and electrically coupled to the sensing elements; a flex cable (<NUM>; <NUM>') positioned against the proximal surface of the substrate over the cavity, the flex cable electrically coupled to the pin block assembly; characterised in that it further comprises:
a first gasket (<NUM>; <NUM>) disposed within the cavity of the substrate over the pin block assembly;
a second gasket (<NUM>; <NUM>) positioned over the flex cable;
a retainer plate (<NUM>; <NUM>) positioned over the second gasket; and
a seal restraint (<NUM>; <NUM>) coupled to the substrate and extending over the retainer plate, the seal restraint applying pressure on the retainer plate and compressing the second gasket against the flex cable to seal the cavity of the substrate.