U.S. patent application number 17/573054 was filed with the patent office on 2022-04-28 for apparatus for ensuring strain gauge accuracy in medical reusable device.
The applicant listed for this patent is Covidien LP. Invention is credited to Joseph Eisinger, Patrick Mozdzierz, David Valentine, Justin Williams.
Application Number | 20220125435 17/573054 |
Document ID | / |
Family ID | 1000006078570 |
Filed Date | 2022-04-28 |
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United States Patent
Application |
20220125435 |
Kind Code |
A1 |
Eisinger; Joseph ; et
al. |
April 28, 2022 |
APPARATUS FOR ENSURING STRAIN GAUGE ACCURACY IN MEDICAL REUSABLE
DEVICE
Abstract
An apparatus for ensuring strain gauge accuracy including a
handle assembly including a controller, an adapter assembly
including a tubular housing having a proximal end portion
configured to couple to the handle assembly and a distal end
portion, a load sensing assembly configured to measure a load
exerted on the tubular housing, and a signal processing circuit
electrically coupled to the load sensing assembly, a memory coupled
to the signal processing circuit, and a calibration assembly
including a biasing member having a known spring rate stored as a
force value in the memory, the calibration assembly configured to
couple to the distal end portion of the adapter assembly. The
signal processing circuit is configured to calibrate the adapter
assembly with the calibration assembly attached thereto by
calculating a correction factor based on a comparison a force of
the spring member measured by the load sensing assembly to the
force value.
Inventors: |
Eisinger; Joseph;
(Northford, CT) ; Mozdzierz; Patrick;
(Glastonbury, CT) ; Valentine; David; (Hamden,
CT) ; Williams; Justin; (Southbury, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Covidien LP |
Mansfield |
MA |
US |
|
|
Family ID: |
1000006078570 |
Appl. No.: |
17/573054 |
Filed: |
January 11, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16441625 |
Jun 14, 2019 |
11241233 |
|
|
17573054 |
|
|
|
|
62695898 |
Jul 10, 2018 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2017/07285
20130101; A61B 2017/00393 20130101; A61B 17/068 20130101; A61B
17/1155 20130101; A61B 2017/00398 20130101; A61B 2017/07271
20130101; A61B 2017/00221 20130101; A61B 2017/00486 20130101; A61B
2017/00473 20130101; A61B 2017/07257 20130101; A61B 2017/00734
20130101 |
International
Class: |
A61B 17/115 20060101
A61B017/115; A61B 17/068 20060101 A61B017/068 |
Claims
1-10. (canceled)
11. An apparatus for ensuring strain gauge accuracy comprising: a
handle assembly including a controller; a tubular housing having a
proximal end portion configured to couple to the handle assembly
and a distal end portion; a load sensing assembly configured to
measure a load exerted on the tubular housing; a signal processing
circuit electrically coupled to the load sensing assembly; a memory
coupled to the signal processing circuit; and a calibration
assembly configured to couple to the distal end portion of the
tubular housing.
12. The apparatus of claim 11, wherein the memory stores a force
measured by the load sensing assembly and a correction factor.
13. The apparatus of claim 12, wherein the handle assembly includes
a display and the signal processing circuit is configured to
display the correction factor on the display.
14. The apparatus of claim 11, wherein the calibration assembly
includes a biasing member that is selectable from a plurality of
biasing members and is selectively couplable to the calibration
assembly.
15. The apparatus of claim 12, wherein the correction factor is
used to adjust a measurement by the load sensing assembly during
use of the apparatus.
16. An apparatus for ensuring strain gauge accuracy comprising: a
handle assembly including a controller; a tubular housing having a
proximal end portion configured to couple to the handle assembly
and a distal end portion; a load sensing assembly configured to
measure a load exerted on the tubular housing; and a signal
processing circuit electrically coupled to the load sensing
assembly; a memory coupled to the signal processing circuit and
configured to store at least one strain value; and a calibration
assembly configured to couple to the distal end portion of the
tubular housing, the calibration assembly including a hard stop,
such that the tubular housing flexes under load while applying
pressure on the hard stop.
17. The apparatus of claim 16, wherein the memory stores a
correction factor.
18. The apparatus of claim 17, wherein the correction factor is
used to correct the at least one strain value.
19. The apparatus of claim 18, wherein the handle assembly includes
a display and the signal processing circuit is configured to
display the correction factor on the display.
20. The apparatus of claim 18, wherein the correction factor is
used to adjust a measurement by the load sensing assembly during
use of the apparatus.
21. A method for ensuring strain gauge accuracy, the method
comprising: coupling a proximal end portion of a tubular housing to
a handle assembly configured to determine accuracy of a strain
gauge; coupling a calibration assembly to a distal end portion of
the tubular housing, the calibration assembly including a hard
stop, such that the tubular housing flexes under load while
applying pressure on the hard stop; measuring, by a load sensing
assembly disposed in the tubular housing, a load exerted on the
tubular housing; and storing at least one strain value to a memory
of the handle assembly.
22. The method of claim 21, further comprising storing a correction
factor in the memory.
23. The method of claim 22, further comprising correcting the at
least one strain value based on the correction factor.
24. The method of claim 23, further comprising displaying the
correction factor on a display of the handle assembly.
25. The method of claim 23, further comprising adjusting a
measurement by the load sensing assembly during use of the handle
assembly based on a correction factor.
26. The method of claim 23, further comprising determining whether
a difference between the stored value and the measured force is
greater than a predetermined threshold value.
27. The method of claim 26, further comprising determining whether
the tubular housing is faulty based on the determination that the
difference between the stored value and the measured force is
greater than the predetermined threshold value.
28. The method of claim 27, displaying on the display that an
adapter assembly of an apparatus is faulty.
29. The method of claim 27, displaying on the display the
determined difference.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 16/441,625, filed on Jun. 14, 2019, which
claims the benefit of the filing date of provisional U.S. patent
application Ser. No 62/695,898, filed Jul. 10, 2018.
BACKGROUND
1. Technical Field
[0002] The present disclosure relates to surgical instrument. More
specifically, the present disclosure relates to ensuring accuracy
of load sensing devices used in handheld electromechanical surgical
systems.
2. Background of Related Art
[0003] One type of surgical instrument is a circular clamping,
cutting and stapling device. Such a device may be employed in a
surgical procedure to reattach rectum portions that were previously
transected, or similar procedures. Conventional circular clamping,
cutting, and stapling devices include a pistol or linear
grip-styled structure having an elongated shaft extending therefrom
and a staple cartridge supported on the distal end of the elongated
shaft. In this instance, a physician may insert an anvil assembly
of the circular stapling device into a rectum of a patient and
maneuver the anvil assembly up the colonic tract of the patient
toward the transected rectum portions. The physician may also
insert the remainder of the circular stapling device (including the
cartridge assembly) through an incision and toward the transected
rectum portions. The anvil and cartridge assemblies are
approximated toward one another and staples are ejected from the
cartridge assembly toward the anvil assembly thereby forming the
staples in tissue to affect an end-to-end anastomosis, and an
annular knife is fired to core a portion of the clamped tissue
portions. After the end-to-end anastomosis has been effected, the
circular stapling device is removed from the surgical site.
[0004] A number of surgical instrument manufacturers have also
developed proprietary powered drive systems for operating and/or
manipulating the end effectors. The powered drive systems may
include a powered handle assembly, which may be reusable, and a
disposable end effector that is removably connected to the powered
handle assembly.
[0005] Many of the existing end effectors for use with existing
powered surgical instruments and/or handle assemblies are driven by
a linear driving force. For example, end effectors for performing
endo-gastrointestinal anastomosis procedures, end-to-end
anastomosis procedures and transverse anastomosis procedures, are
actuated by a linear driving force. As such, these end effectors
are not compatible with surgical instruments and/or handle
assemblies that use rotary motion.
[0006] In order to make the linear driven end effectors compatible
with powered surgical instruments that use a rotary motion to
deliver power, a need exists for adapters to interconnect the
linear driven end effectors with the powered rotary driven surgical
instruments. Due to powered actuation of these adapters and end
effectors various sensors are used to measure mechanical forces and
strain imparted on them during use. Accordingly, there is a need
for systems and methods to calibrate and/or verify operation of
these sensors.
SUMMARY
[0007] Powered surgical instruments may include various sensors for
providing feedback during their operation. Feedback detection
enables anvil detection, staple detection, cutting to a force for
consistent cutting, controlled tissue compression to avoid tissue
damage while maximizing staple formation consistency, excessive
load adjustment of stroke to optimized staple formation, and tissue
thickness identification. Use of load sensing devices, such as
strain gauges, in reusable devices enables many powered, reusable,
intelligent devices. Maintaining load sensing device calibration
ensures accurate readings or measurements. This device calibration
enables a higher degree of load sensing device accuracy confidence,
than that gained through reliability testing. This greater
confidence may enable load sensing devices, that are unable to
establish statistical reliability, to be reused in the field
without risk to the patient.
[0008] The present disclosure provides for a calibration assembly
having accurate feedback detection. This eliminates the problem of
un-calibrated feedback detection and the need for reliability
testing, which is required to prove that the load sensing device
reading correlation to actual forces maintains accuracy. The
apparatus incorporates an external fixture to enable the adapter to
check the load sensing device accuracy.
[0009] According to one embodiment of the present disclosure, an
apparatus for ensuring strain gauge accuracy is disclosed. The
apparatus includes a handle assembly including a controller, an
adapter assembly including a tubular housing having a proximal end
portion configured to couple to the handle assembly and a distal
end portion, a load sensing assembly configured to measure a load
exerted on the tubular housing, and a signal processing circuit
electrically coupled to the load sensing assembly, a memory coupled
to the signal processing circuit, and a calibration assembly
including a biasing member having a known spring rate stored as a
force value in the memory, the calibration assembly configured to
couple to the distal end portion of the adapter assembly. The
signal processing circuit is configured to calibrate the adapter
assembly with the calibration assembly attached thereto by
calculating a correction factor based on a comparison a force of
the spring member measured by the load sensing assembly to the
force value.
[0010] According to one aspect of the above embodiments, the memory
stores the force measured by the load sensing assembly and the
correction factor. According to another aspect of the present
disclosure the handle assembly includes a display and the
controller is configured to display the correction factor on the
display. According to a further embodiment of the present
disclosure, the biasing member is selectable from a plurality of
biasing members and is selectively couplable to the calibration
assembly. According to another aspect of the present disclosure the
correction factor is used to adjust a measurement by the load
sensing assembly during use of the apparatus.
[0011] According to one embodiment of the present disclosure, an
apparatus for ensuring strain gauge accuracy is disclosed. The
apparatus includes a handle assembly including a controller, an
adapter assembly which includes a tubular housing having a proximal
end portion configured to couple to the handle assembly and a
distal end portion, a load sensing assembly configured to measure a
load exerted on the tubular housing, and a signal processing
circuit electrically coupled to the load sensing assembly, a memory
coupled to the signal processing circuit, the memory storing at
least one strain value, and a calibration assembly including a hard
stop that the adapter assembly, the calibration assembly configured
to couple to the distal end portion of the adapter assembly, such
that the adapter assembly flexes under load while applying pressure
on the hard stop. The signal processing circuit is configured to
calibrate the adapter assembly with the calibration assembly
attached thereto by calculating a correction factor based on a
deviation between the at least one strain value and a force value
measured by the load sensing assembly during flexing of the adapter
assembly under load while applying pressure on the hard stop.
[0012] According to one aspect of the above embodiments, the memory
stores the correction factor. According to another aspect of the
above embodiments, the correction factor is used to correct at
least one strain value. According to a further aspect of the above
embodiments, the handle assembly includes a display and the
controller is configured to display the correction factor on the
display. The correction factor is used to adjust a measurement by
the load sensing assembly during use of the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Embodiments of the present disclosure are described herein
with reference to the accompanying drawings, wherein:
[0014] FIG. 1 is a perspective view of a handheld surgical
instrument, an adapter assembly, an end effector having a reload
and an anvil assembly according to an embodiment of the present
disclosure;
[0015] FIG. 2 is a perspective view illustrating a connection of
the adapter assembly and the handle assembly of FIG. 1 according to
an embodiment of the present disclosure;
[0016] FIG. 3 is perspective view of internal components of the
handle assembly according to an embodiment of the present
disclosure;
[0017] FIG. 4 is a perspective view of the adapter assembly of FIG.
1 without the reload according to an embodiment of the present
disclosure;
[0018] FIG. 5 is a side, cross-sectional view, of the reload of
FIG. 1 according to an embodiment of the present disclosure;
[0019] FIG. 6 is a perspective view of the distal end portion of
the adapter assembly according to an embodiment of the present
disclosure;
[0020] FIG. 7 is a side, cross-sectional view, of the distal end
portion of the adapter assembly of FIG. 1 with a trocar member
coupled to a calibration assembly according to an embodiment of the
present disclosure;
[0021] FIG. 8 is a side, cross-sectional view, of the distal end
portion of the adapter assembly of FIG. 1 with the staple band
making contact with the calibration assembly according to an
embodiment of the present disclosure;
[0022] FIG. 9 is a side, cross-sectional view, of the distal end
portion of the adapter assembly of FIG. 1 coupled to the
calibration assembly, where the trocar member is retracted and the
staple band is extended according to an embodiment of the present
disclosure;
[0023] FIG. 10 is a perspective view of a distal portion of a
calibration assembly according to another embodiment of the present
disclosure;
[0024] FIGS. 11 is a side, cross-sectional view, of the distal end
portion of the adapter assembly of FIG. 1 coupled with the
calibration assembly of FIG. 10, where the trocar member is
extended, according to an embodiment the present disclosure;
[0025] FIGS. 12 is a side, cross-sectional view, of the distal end
portion of the adapter assembly of FIG. 1 coupled with the
calibration assembly of FIG. 10, where the staple band is extended
to contact the calibration assembly, according to an embodiment the
present disclosure;
[0026] FIGS. 13 is a side, cross-sectional view, of the distal end
portion of the adapter assembly of FIG. 1 coupled with the
calibration assembly of FIG. 10, where the trocar and the staple
band are retracted, according to an embodiment the present
disclosure; and
[0027] FIG. 14 is a side, cross-sectional view of the distal end
portion of the adapter assembly of FIG. 1 coupled with a
calibration assembly according to a further embodiment the present
disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
[0028] 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. As used herein, the term "clinician" refers to a
doctor, a nurse or any other care provider and may include support
personnel. Throughout this description, the term "proximal" will
refer to the portion of the device or component thereof that is
closer to the clinician and the term "distal" will refer to the
portion of the device or component thereof that is farther from the
clinician. Additionally, in the drawings and in the description
that follows, terms such as front, rear, upper, lower, top, bottom,
and similar directional terms are used simply for convenience of
description and are not intended to limit the disclosure. In the
following description, well-known functions or constructions are
not described in detail to avoid obscuring the present disclosure
in unnecessary detail.
[0029] The present disclosure relates to powered surgical
instruments having electronic sensors for monitoring mechanical
strain and forces imparted on components of the powered surgical
instruments. More particularly, this disclosure relates to load
measuring sensors including load sensing devices as well as analog
and digital circuitry that are hermetically sealed such that the
load sensors are configured to resist harsh environments. In the
event that electrical connections of the powered surgical
instruments are compromised during use, measurement signals output
by the sensors of the present disclosure remain unaltered. In
addition, the sensors are programmable allowing for adjustments to
gain and offset values in order to optimize the measurement
signals.
[0030] With reference to FIG. 1, a powered surgical instrument 10
includes a handle assembly 20, which is configured for selective
connection with an adapter assembly 30, which in turn, is
configured for selective connection with an end effector, such as
an annular reload 40. Although generally referred to as being a
powered surgical instrument, it is contemplated that the surgical
instrument 10 may be a manually actuated and may include various
configurations.
[0031] The handle assembly 20 includes a handle housing 22 having a
lower housing portion 24, an intermediate housing portion 26
extending from and/or supported on a portion of the lower housing
portion 24, and an upper housing portion 28 extending from and/or
supported on a portion of the intermediate housing portion 26. As
shown in FIG. 2, a distal portion of the upper housing portion 28
defines a nose or connecting portion 28a that is configured to
accept a proximal end portion 30b of the adapter assembly 30.
[0032] With reference to FIG. 3, the handle assembly 20 includes
one or more motors 36 which are coupled to a battery 37. The handle
assembly 20 also includes a main controller 38 for operating the
motors 36 and other electronic components of the handle assembly
20, the adapter assembly 30, and the reload 40. The motors 36 are
coupled to corresponding drive shafts 39 (FIG. 2), which are
configured to engage sockets 33 on the proximal end portion 30b,
such that rotation of the drive shafts 39 is imparted on the
sockets 33. The actuation assembly 52 (FIG. 6) is coupled to one of
the sockets 33. The actuation assembly 52 is configured to transfer
rotational motion of the sockets 33 into linear motion and to
actuate the reload 40 along with the anvil assembly 58. There are
three actuation assemblies in the adapter assembly 30. The first
actuation assembly is configured to convert rotational motion
provided by the handle assembly 20 into axial translation useful
for advancing/retracting the trocar member 50 slidably disposed
within the distal end portion 30c of the adapter assembly 30. The
second actuation assembly is configured to convert rotational
motion provided by the handle assembly 20 into axial translation
useful for advancing/retracting the staple band slidably disposed
within the distal end portion 30c of the adapter assembly 30. The
third actuation assembly is configured to convert rotational motion
provided by the handle assembly 20 into axial translation useful
for advancing/retracting a knife slidably disposed within the
distal end portion 30c of the adapter assembly 30. The handle
assembly 20 further includes a display screen 146 supported on main
controller circuit board 142b. Display screen 146 is visible
through a clear or transparent window.
[0033] With reference to FIG. 4, the adapter assembly 30 includes a
tubular housing 30a that extends between a proximal end portion 30b
that is configured for operable connection to the connecting
portion 28a of the handle assembly 20 and an opposite, distal end
portion 30c that is configured for operable connection to the
reload 40. In this manner, the adapter assembly 30 is configured to
convert a rotational motion provided by the handle assembly 20 into
axial translation useful for advancing/retracting a trocar member
50 slidably disposed within the distal end portion 30c of the
adapter assembly 30 (FIG. 5) for firing staples of the reload
40.
[0034] With reference to FIG. 2, the connecting portion 28a
includes an electrical receptacle 29 having a plurality of
electrical contacts 31, which are in electrical communication with
electronic (e.g., main controller 38) and electrical components
(e.g., battery 37) of the handle assembly 20. The adapter assembly
30 includes a counterpart electrical connector 32 that is
configured to engage the electrical receptacle 29. The electrical
connector 32 also includes a plurality of electrical contacts 34
that engage and electrically connect to their counterpart
electrical contacts 31.
[0035] With reference to FIG. 4, the trocar member 50 is slidably
disposed within the tubular housing 30a of the adapter assembly 30
and extends past the distal end portion 30c thereof. In this
manner, the trocar member 50 is configured for axial translation,
which in turn, causes a corresponding axial translation of an anvil
assembly 58 (FIG. 1) of the reload 40 to fire the staples (not
shown) disposed therein. The trocar member 50 includes a proximal
end which mates with the tubular housing 30a of the adapter
assembly 30. A distal end portion of the trocar member 50 is
configured to selectively engage the anvil assembly 58 of the
reload 40 (FIG. 4). In this manner, when the anvil assembly 58 is
connected to the trocar member 50, as will be described in detail
hereinbelow, axial translation of the trocar member 50 in the first
direction results in an opening of the reload 40, and axial
translation of the trocar member 50 in a second, opposite
direction, results in a closing of the reload 40.
[0036] As illustrated in FIGS. 1 and 5, the reload 40 is configured
for operable connection to adapter assembly 30 and is configured to
fire and form an annular array of surgical staples, and to sever a
ring of tissue. The reload 40 includes a housing 42 having a
proximal end portion 42a and a distal end portion 42b and a staple
cartridge 44 fixedly secured to the distal end portion 42b of the
housing 42. The proximal end portion 42a of the housing 42 is
configured for selective connection to the distal end portion 30c
of the adapter assembly 30 and includes a means for ensuring the
reload 40 is radially aligned or clocked relative to the adapter
assembly 30.
[0037] With reference to FIG. 5, the housing 42 of the reload 40
includes an outer cylindrical portion 42c and an inner cylindrical
portion 42d. The outer cylindrical portion 42c and the inner
cylindrical portion 42d of the reload 40 are coaxial and define a
recess 46. The recess 46 of the reload 40 includes a plurality of
longitudinally extending ridges or splines 48 projecting from an
inner surface thereof which is configured to radially align the
anvil assembly 58 relative to the reload 40 during a stapling
procedure.
[0038] With reference now to FIG. 6, adapter assembly 30 includes
an electrical assembly 60 disposed therewithin, and configured for
electrical connection with and between handle assembly 20 and
reload 40. Electrical assembly 60 provides for communication (e.g.,
identifying data, life-cycle data, system data, load sense signals)
with the main controller 38 of the handle assembly 20 through the
electrical receptacle 29.
[0039] Electrical assembly 60 includes the electrical connector 32,
a proximal harness assembly 62 having a ribbon cable, a distal
harness assembly 64 having a ribbon cable, a load sensing assembly
66, and a distal electrical connector 67. The electrical assembly
60 also includes the distal electrical connector 67 which is
configured to selectively mechanically and electrically connect to
a chip assembly (not shown) of reload 40.
[0040] Electrical connector 32 of electrical assembly 60 is
supported within the proximal end portion 30b of the adapter
assembly 30. Electrical connector 32 includes the electrical
contacts 34 which enable electrical connection to the handle
assembly 20. Proximal harness assembly (not shown) is electrically
connected to the electrical connector 32.
[0041] Load sensing assembly 66 is electrically connected to
electrical connector 32 via proximal and distal harness assemblies
(not shown). Shown in FIG. 6, the load sensing assembly 66 includes
a sensor 68 and a memory 69. The sensor 68 is electrically
connected to the memory 69. Load sensing assembly 66 is also
electrically connected to distal harness assembly 64 via a sensor
flex cable. As shown in FIG. 6, an actuation assembly 52, which is
coupled to the trocar member 50, extends through the load sensing
assembly 66. The load sensing assembly 66 provides strain
measurements imparted on the adapter assembly 30 during movement of
the trocar member 50, the anvil assembly 58, and other mechanical
actuations, e.g., knife.
[0042] For a detailed description of an exemplary powered surgical
stapler including an adapter assembly and a reload, reference may
be made to commonly owned U.S. Patent Application Publication No.
2016/0310134 to Contini et al., titled "Handheld Electromechanical
Surgical System," filed Apr. 12, 2016 incorporated by reference
hereinabove.
[0043] FIGS. 7-9, depict an apparatus for ensuring strain gauge
accuracy in accordance with the present disclosure. In one
embodiment, the calibration assembly 700 includes a biasing member
704, having a predetermined spring load. The calibration assembly
700 includes a cylindrical housing 712, an opening 703 at a distal
end, a loading area 708, and two opposing arms 711a, 711b. Located
on the distal portion of each arm 711a, 711b is a catch 702 and an
auto release latch 713 for moving the arms 711a and 711b apart. As
the trocar member is extended through the opening 703 in the
calibration assembly 700 as in FIG. 7, each of the catches 702
engages a corresponding opening 714 in the actuation assembly
52.
[0044] As shown in FIG. 8, when the trocar member 50 is retracted
and the staple band 706 is extended, the calibration assembly 700
compresses the biasing member 704. The staple band 706 at this
point is applying pressure to the loading area 708. The sensor 68
is calibrated by cycling power while the calibration assembly 700
is attached to the adapter assembly 30. The known spring load of
the biasing member 704 and the sensing assembly 66 reading may be
used to update the adapter assembly's memory 69 to apply the most
recent conversion formula for the sensing assembly 66 electrical
resistance to force correlation. This may be accomplished in
several ways. In one embodiment, the known spring load of the
biasing member 704 may be measured by the load sensing assembly 66
in the adapter assembly 30. The calibrated biasing member 704
deflects a certain known distance. The biasing member 704 signals a
certain known force has been reached. In another embodiment, the
known spring load may be stored in the memory 69 and used with the
calculated distance the adapter assembly 30 has traveled, to
calculate force. For example, multiple biasing members could be
used with different spring loads, which bottom out at different
differences, thus increasing the amount of data points that may be
used for calibration.
[0045] A signal processing circuit is configured to calibrate the
adapter assembly 30 with the calibration assembly 700 attached
thereto by calculating a correction factor based on a comparison a
force of the biasing member measured by the load sensing assembly
66 to the force value. The memory 69 of FIG. 6. stores the force
measured by the load sensing assembly and the correction factor.
The main controller 38 is configured to display the correction
factor on the display screen 146 of FIG. 3. The main controller 38
uses the correction factor to adjust the measurements by the load
sensing assembly 66 during use of the surgical instrument 10. As
shown in FIG. 9, after calibration, when the staple band 706 is
retracted, the trocar member 50 may be retracted, ejecting the
calibration assembly 700 automatically, as the adapter assembly 30
cams off of the as the auto release latch 713.
[0046] FIGS. 10-13, depict an apparatus for ensuring strain gauge
accuracy in accordance with the present disclosure. In an
embodiment, the calibration assembly 800 of FIG. 10 has a hard
stop, the loading surface 802, that the moving components of the
adapter assembly 30 can apply pressure towards. The calibration
assembly 800 flexes under load application, e.g., clamping, making
the adapter assembly 30 itself act like a spring under load. The
calibration assembly 800 includes an arm 804 having a latch 902,
the arm is connected pivotally at a distal end portion of the
calibration assembly 800 with a fastener 805. The calibration
assembly 800 also includes an opening 803 at the proximal end for
the trocar member 50 to be inserted and extended there through. The
calibration assembly 800 has a tubular shape with a large flange
807 at the distal end for aiding a user during attachment of the
calibration assembly 800 to the adapter assembly 30.
[0047] Referring to FIGS. 11-13, a latch 902 engages the trocar
member 30 as the trocar member is inserted into the calibration
assembly 800. As shown in FIG. 11, the proximal end of the trocar
member 50 is inserted into the opening 803 on the distal end of the
calibration assembly 800. The latch 902 engages an opening 714 in
the actuation assembly 52 as the trocar member 50 is extended. As
shown in FIG. 12, the staple band 706 extends to contact the
calibration assembly 800 before the trocar member 50 retracts
fully. The loading surface 802 of the calibration assembly 800
makes contact with the staple band 706 starting the calibration
load sequence. The load sensing assembly 66 measures a signal
produced by flexing the adapter assembly 30 against the hard stop
of the loading surface 802 of the calibration assembly 700, and
stores this signal as a force value in the memory 69. The signal
processing circuit is configured to determine if a relationship
between the force value and the stored strain has changed. If a
ratio between the force value and the stored strain changes, the
signal processing circuit is configured to determine the deviation
and store the deviation as a correction factor. The memory 69
stores the correction factor. The stored correction factor is then
used to correct the stored strain.
[0048] The main controller 38 is configured to display the
correction factor on the display screen 146 of FIG. 3. The main
controller 38 uses the correction factor to adjust the measurements
by the load sensing assembly 66 during use of the surgical
instrument 10. As shown in FIG. 13 after load calibration, the
staple band 706 is retracted and the trocar member 50 is continued
to be pulled in. The calibration assembly 800 has a latch auto
remove tab 904 that is used to cam the latch 902 off the trocar
member 50.
[0049] While the adapter assembly 30 spring load may not be
calibrated, recalling from memory 69 the previous loading
measurements, the main controller 38 can check to see if signal
from the load sensing assembly 66 and its relationship to the
adapter assembly's 30 spring load has changed. If the ratio of
strain gauge signal to the adapter assembly 30 spring load has
degraded from its known ratio, the main controller 38 can recognize
the deviation and either compensate, signal an error to the user,
or decommission the adapter assembly 30. The known ratio may be
calibrated in advance at manufacture. In order to compensate for
the error, the main controller 38 utilizes the deviation to
calculate a correction factor. This correction factor is stored in
the memory 69 and may be used to correct for the deviation.
[0050] FIG. 14 depicts a side view of another embodiment of the
distal end portion of the adapter assembly of FIG. 1 coupled to a
calibration assembly 1000 according to an embodiment the present
disclosure. A latching mechanism 1002, which Isa spring loaded
mechanism, latches onto a trocar member 50, by inserting the trocar
member 50 and having the staple band 706 contact the loading
surface 802. The latching mechanism 1002 acts as a latch to hold
the trocar member 50 in place. The calibration assembly 1000 may be
pulled off of the trocar member 50 at a predetermined load, which
indicates a force for load sensing assembly 66 calibration. This
force may be measured by the load sensing assembly 66. This
measured force may be stored in the memory 69 and the main
controller 38 can compare this value to a stored value. Based on
the difference between the stored value and the measured force, a
correction factor may be calculated by the main controller 38. This
correction factor is then stored in the memory 69, where it is used
be the main controller 38 to compensate for the deviation in force.
In an embodiment, a user could be notified of the error on the
display screen 146 of FIG. 3, and/or the adapter assembly 30 could
be decommissioned.
[0051] It will be understood that various modifications may be made
to the embodiments of the presently disclosed adapter assemblies.
Therefore, the above description should not be construed as
limiting, but merely as exemplifications of embodiments. Those
skilled in the art will envision other modifications within the
scope and spirit of the present disclosure.
* * * * *