System and method for monitoring blood pressure with a powered linear actuator

Abstract

The present invention relates to a system and method for monitoring blood pressure with a powered linear actuator. A tissue property sensing system includes a sensing assembly that is movable along a drive screw and includes an outer shaft, an anvil, a central driver, a piston, and a tension spring. The piston includes a distal arm having a distal portion and a head extending from the distal portion. The piston is movable within the outer shaft to move the head relative to the anvil between an open configuration and a closed configuration, wherein in the closed configuration, the head of the piston and the anvil are positioned to clamp tissue and block blood flow in the tissue. The tension spring is coupled to the central driver and the piston to urge the piston toward the central driver and the head of the piston toward the anvil.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 62 / 878,816, filed on July 26, 2019, the entire contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates to systems and methods for measuring tissue properties, and more particularly to systems and methods for occluding blood flow in target tissue to measure tissue properties during minimally invasive surgery. Background Art

[0004] During a surgical procedure, medical personnel or clinicians may find it necessary to determine one or more tissue characteristics before acting on the tissue. For example, during colorectal surgery requiring anastomosis, the clinician visually inspects the tissue of the colon to be removed. Typically, during this inspection, the clinician visually observes the colon and determines which portion or portions of the colon are diseased. The clinician then identifies which diseased portions of the colon will be removed. The inspection can be performed via one or more imaging devices located within or near the colon. Various other surgical procedures require a similar visual inspection of the tissue to determine which portions of the tissue will be removed.

[0005] Depending on the procedure and the tissue being examined, the clinician may not be able to identify all areas of interest due to the clinician's limited visibility. For example, referring again to the anastomosis procedure, the colon may include abnormal growths that may not be easily visible by examining the exterior of the colon. Thus, the clinician may also need to examine the interior of the tissue to be resected. Examining the interior of the colon may require an additional clinician and / or an imaging or visualization device (e.g., an endoscope) to assist in imaging the interior of the colon. Care must be taken when aligning the interior and exterior views during the imaging process.

[0006] Thus, there is a need for improved devices and methods for assessing tissue properties during surgical procedures. Summary of the Invention

[0007] One aspect of the present disclosure relates to a tissue property sensing system comprising an adapter assembly having a drive interface, a drive screw, and a sensing assembly. The drive screw is coupled to the drive interface of the adapter assembly and extends from the adapter assembly. The sensing assembly is movable along the drive screw and comprises an outer shaft, an anvil, a central driver, a piston, and a tension spring. The anvil is supported on a distal portion of the outer shaft. The central driver is movable within the outer shaft and defines a longitudinal bore. The piston comprises a distal arm having a distal portion and a head extending from the distal portion of the distal arm. The piston is movable within the outer shaft to move the head relative to the anvil between an open configuration and a closed configuration, wherein in the closed configuration, the head of the piston and the anvil are positioned to clamp tissue and block blood flow within the tissue. The tension spring is coupled to the central driver and the piston to urge the piston toward the central driver and the head of the piston toward the anvil.

[0008] In an embodiment, said head of said piston supports at least one sensor.

[0009] In some embodiments, the piston includes a proximal arm and the central drive includes a housing, wherein the proximal arm is received within the housing to prevent rotational movement of the piston relative to the central drive.

[0010] In certain embodiments, the central drive includes a threaded opening, and a portion of the drive screw is received within the threaded opening such that rotation of the drive screw relative to the central drive causes the central drive to move longitudinally within the outer shaft.

[0011] In embodiments, rotation of the drive screw in a first direction moves the central driver distally relative to the adapter assembly, and rotation of the drive screw in a second direction moves the central driver proximally relative to the adapter assembly.

[0012] In some embodiments, in the closed configuration, the sensing assembly applies a predetermined range of forces to tissue disposed within the sensing assembly.

[0013] In some embodiments, the outer shaft defines a window and the proximal arm of the piston supports a plurality of indicators, wherein one or more of the plurality of indicators are visible through the window in the closed configuration to indicate the thickness of the tissue located between the head of the piston and the anvil.

[0014] In an embodiment, a sensor is positioned on one of the head of the piston or the anvil.

[0015] In some embodiments, the central driver supports a retaining pin disposed within the longitudinal bore, and the tension spring is coupled to the retaining pin.

[0016] Another aspect of the present disclosure relates to a method for sensing blood pressure within a tissue property sensing device, wherein the method includes: positioning tissue between a head of a piston and an anvil, the piston and the anvil being connected together via a spring having a known spring constant; blocking blood flow within the tissue by moving the head of the piston and the anvil of the tissue property sensing device to a closed configuration and increasing the tension in the tension spring; moving the head of the piston away from the anvil to reduce the pressure applied to the target tissue to allow the blood to begin flowing again within the tissue; and calculating the patient's systolic blood pressure obtained at the tissue when the blood within the target tissue begins to flow again.

[0017] In an embodiment, after determining the systolic blood pressure of the patient, the method includes moving the head of the piston further away from the anvil so that the blood flow in the tissue is not blocked; and calculating the diastolic blood pressure of the patient obtained at the tissue when it is determined that the blood flow in the target tissue is not blocked.

[0018] In some embodiments, determining the systolic pressure includes: determining the position of the head of the piston relative to the fixed component of the tissue property sensing device when the blood begins to flow again in the tissue; calculating the length of the spring based on the determined position; and calculating the force applied by the spring on the tissue based on the length of the spring.

[0019] In an embodiment, determining the diastolic pressure includes: determining the position of the head of the piston relative to the fixed component of the tissue characteristic sensing device in response to determining that blood flow is no longer blocked in the tissue; calculating the length of the spring based on the determined position; and calculating the force applied by the spring on the tissue based on the length of the spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various embodiments of the disclosed systems and methods are described below with reference to the accompanying drawings, in which:

[0021] Figure 1 is a side perspective view of a tissue characteristic sensing device with a sensing assembly in an open configuration according to an exemplary embodiment of the present disclosure;

[0022] Figure 2 yes Figure 1 a side perspective view of a tissue characteristic sensing device with multiple parts separated;

[0023] Figure 3 yes Figure 1 an enlarged view of the indicated detail area;

[0024] Figure 4 yes Figure 3 An enlarged view of the indicated area of ​​detail is shown;

[0025] Figure 5 It is along Figure 1 A cross-sectional view taken along section line 5-5 of the tissue characteristic sensing device in an open configuration;

[0026] Figure 6 yes Figure 5 an enlarged view of the indicated detail area;

[0027] Figure 7 It is along Figure 1 a cross-sectional view taken along line 5-5 of the tissue characteristic sensing device in a close configuration;

[0028] Figure 8 yes Figure 7 an enlarged view of the indicated detail area;

[0029] Figure 9 It is along Figure 1 a cross-sectional view taken along line 5-5 of the tissue characteristic sensing device in a partially approximated configuration;

[0030] Figure 10 yes Figure 9 an enlarged view of the indicated detail area;

[0031] Figure 11 Is used with Figure 1 A perspective view of a handle assembly connected to a tissue characteristic sensing device;

[0032] Figure 12 is a schematic block diagram of a computing device that may be employed according to various embodiments of the present disclosure; and

[0033] Figure 13A The embodiment of the present disclosure is shown for controlling Figure 1 Flowchart of the process of the tissue characteristic sensing device. DETAILED DESCRIPTION

[0034] The disclosed tissue characteristic sensing device will now be described in detail with reference to the accompanying drawings. It should be understood that the same reference numerals may represent the same or corresponding elements in each of the several views. As used herein, the term "proximal" generally refers to the portion of the element or feature that is closer to the clinician, while the term "distal" generally refers to the portion of the element or feature that is farther away from the clinician; the term "clinician" generally refers to medical personnel, including doctors, surgeons, nurses, auxiliary personnel, etc.; and directional terms such as front, back, above, below, top, bottom, distal, proximal and similar terms are used to assist in understanding the present specification and are not intended to limit the present disclosure.

[0035] Now refer to Figures 1 to 4 , an embodiment of a tissue property sensing device is generally indicated as tissue property sensing device 100. Tissue property sensing device 100 includes an adapter assembly 102 configured to couple to a remote device, such as, for example, a handheld device 200 ( Figure 11 ) or a robotic surgical system (not shown). For clarity, the reference tissue characteristic sensing device 100 is generally referred to as the handheld device 200 ( Figure 11 ) and their operation, but it should be understood that the robotic surgical system can be connected and operated similarly. Examples of such systems may be found by reference to U.S. Patent Application Publication No. 2015 / 0157320, filed by Zergiebel et al. on November 21, 2014, entitled “ADAPTER ASSEMBLY FOR INTERCONNECTING ELECTROMECHANICAL SURGICAL DEVICES AND SURGICAL LOADING UNITS, AND SURGICAL SYSTEMS THEREOF” (now U.S. Patent No. 9,918,713), U.S. Patent Application Publication No. 2016 / 0310134, filed by Contini et al. on April 12, 2016, entitled “HANDHELD ELECTROMECHANICAL SURGICAL SYSTEM,” and U.S. Patent No. 8,828,023, each of which is incorporated herein by reference in its entirety. Although the handheld device 200 ( Figure 11 ) is shown as an electrically powered device, but it is contemplated that a manually powered handheld device may also be provided to drive the tissue characteristic sensing device 100.

[0036] refer to Figure 2 and Figure 5, the adapter assembly 102 includes one or more proximal connector sleeves 108 ( Figure 5 ) of the adapter interface, the proximal connector sleeve being configured to accommodate one or more drive screws 208 ( Figure 11 ), the drive screw extends from the handheld device 200 (see Figure 11 In response to engagement of a motor (e.g., a motor of the handheld device 200 or a robotic surgical system, not explicitly shown), the drive screw 208 rotates the proximal connector sleeve 108 clockwise or counterclockwise. The proximal connector sleeve 108 may be operably coupled to the drive interface 106, and it should be understood that in embodiments such as Figure 2 ), the proximal connector sleeve 108 and the drive interface 106 may be integrally formed and / or may be the same component. For a detailed description of the operation and engagement of the adapter (e.g., adapter assembly 102) by the handheld device 200, reference may be made to U.S. Provisional Patent Application No. 62 / 597,595 filed by Williams on December 12, 2017, entitled “SURGICAL INSTRUMENTS INCLUDING DEVICES FOR SENSING TISSUE PROPERTIES AND METHODS THEREOF,” the entire contents of which are incorporated herein by reference.

[0037] The drive interface 106 includes a flange 112 that extends around the periphery of the drive interface 106. The flange 112 is configured to engage a proximal portion of a compression spring 114 and receive a longitudinal force applied from the compression spring 114 to urge the drive interface 106 proximally into the cavity "C" ( Figure 5 ). The drive interface 106 further includes a distal connector sleeve 110 defining a corresponding recess extending proximally inwardly from a distal portion of the drive interface 106. The proximal connector sleeve 108 and the distal connector sleeve 110 are configured to receive the drive screw 208 ( Figure 11 ) and the drive head 116. In an embodiment, when rotatably coupled to one or more drive screws 208 ( Figure 11), the drive interface 106 can be engaged or disengaged by advancing one or more drive screws 208 of the handheld device 200 distally or proximally relative to the proximal connector sleeve 108. Such distal and proximal advancement of the one or more drive screws 208 compresses or decompresses the compression spring 114, thereby causing the proximal portion of the drive head 116 to enter or exit the distal connector sleeve 110 of the drive interface 106. The distal portion of the drive screw 208 has a configuration corresponding to the configuration of the recess defined by the proximal connector sleeve 108 (e.g., a flat head screw, a Phillips head screw, a Torx head screw, etc.). Similarly, the proximal portion of the drive head 116 has a configuration corresponding to the recess 110a defined by the proximal connector sleeve 108. The drive head 116 extends distally to form a drive screw shaft 120. In an embodiment, the drive screw shaft 120 has a proximal flange 118a and a distal flange 118b that are spaced apart from each other and extend around the drive screw shaft 120. The proximal flange 118a can be configured to be received in a corresponding channel defined by the housing 104 of the adapter (not explicitly shown), and the distal flange 118b can be disposed around the drive screw shaft 120 and configured to be received in a separate corresponding channel of the housing 104 of the adapter assembly 102 (see FIG. Figure 5 ) to longitudinally fix the drive screw shaft 120 relative to the housing 104. The drive screw shaft 120 also includes threads 122 disposed around a distal portion thereof. The threads 122 are configured to rotatably engage corresponding threads defined within a threaded opening of the center driver 124 to move the center driver 124 proximally or distally when rotated in a first direction or a second direction, respectively. It is contemplated that the drive screw shaft 120 can be formed from any desired metal, plastic, composite material, alloy, etc., and in an embodiment, can be made from lead.

[0038] refer to Figure 3 and Figure 4 , the center driver 124 includes a base 126 and a driver housing 128 that extends distally from the base 126. The base 126 and the driver housing 128 define a through hole "B". The through hole "B" is defined by an inner surface 131 that includes a threaded portion 127 that is configured to be rotatably engaged by the threads 122 of the drive screw shaft 120. In an embodiment, the center driver 124 ( Figure 6 ) can extend along any one or more portions between the proximal and distal portions of the central driver 124. The driver housing 128 defines a pair of apertures 130 ( Figure 2), the pair of apertures 130 are configured to receive a portion of a securing pin 132. Specifically, the securing pin 132 can include a spring-loaded and outwardly biased securing member 134 disposed within a housing of the securing pin 132. The securing member 134 can be advanced inwardly relative to the housing of the securing pin 132, and then the securing pin 132 can be inserted into the lumen of the driver housing 128. The securing pin 132 can then be aligned with the pair of apertures 130, thereby allowing the securing member 134 to move outwardly and through the pair of apertures 130 to secure the securing pin 132 within the central driver 124.

[0039] The central drive 124 further includes a piston arm housing 136 configured to house a portion of the proximal piston arm 140 to maintain the angular position of the piston 138 relative to the central drive 124 (e.g., to prevent the piston 138 from rotating relative to the central drive 124). Figure 2 As shown), the fixing member 134 of the fixing pin 132 can extend outward and be configured to extend along the pin window "P" ( Figure 2 ) slides, thereby limiting the rotational movement of the center drive 124 relative to the inner shaft "IS".

[0040] Continue to refer Figures 1 to 4 , especially reference Figure 3 and Figure 4 , the sensing assembly includes a central driver 124, a piston 138, and a tension spring 160 positioned to exert a force on both the central driver 124 and the piston 138 to urge them toward a close configuration ( Figure 9 ). The piston 138 includes a proximal piston arm 140 and a distal piston arm 144, which extend away from the proximal piston arm 140. The proximal piston arm 140 has a generally rectangular cross-section and a plurality of indicators 142 disposed along its top. The plurality of indicators 142 are configured to pass through the outer shaft "OS" ( Figure 2 ) is observed through the window 162. The distal piston arm 144 of the piston 138 has a housing that defines an aperture 146 ( Figure 4), the aperture 146 is positioned along the proximal portion of the distal piston arm 144. Aperture 146 is configured to accommodate the distal portion of a tension spring 160. The distal piston arm 144 includes a head 148 extending inwardly therefrom. In embodiments, the head 148 can be shaped to correspond to the shape of the head 152 of anvil 150, which is coupled to the outer shaft "OS" of the tissue property sensing device 100. In embodiments, the head 148 of the distal piston arm 144 can support one or more sensors "S," such as, for example, a piezoresistive force sensor, an optical sensor, an impedance sensor, and the like. For a more general and detailed discussion of sensors used in conjunction with tissue property sensing devices and sensing systems, reference may be made to U.S. Provisional Patent Application Publication No. 62 / 661,821 to Eschbach, entitled "SURGICAL DEVICE INCLUDING SYSTEM FOR SENSING TISSUE PROPERTIES AND METHODS THEREOF," the entire contents of which are incorporated herein by reference.

[0041] Continue to refer Figure 2 , the anvil 150 is inserted into the opening defined by the distal portion of the outer shaft "OS" of the tissue property sensing device 100. More specifically, the anvil 150 is secured along the interior of the outer shaft "OS" by any suitable means, such as, but not limited to, friction fit, adhesive, crimping, welding, or other known connection techniques. The anvil 150 defines a head 152 and includes a flange 154 extending proximally from a peripheral wall 156 of the anvil 150 relative to the head 152. The flange 154 limits the proximal movement of the anvil 150 toward the outer shaft "OS" of the tissue property sensing device 100 to allow the anvil 150 to accommodate and compress the target tissue thereon while transmitting the force received by the head 152 to the outer shaft "OS". The head 152 of the anvil 150 also includes a passage 158 that is configured to slidably receive the proximal piston arm 140 of the piston 138 therethrough, thereby allowing the proximal piston arm 140 to be inserted into the piston arm housing 136 of the central drive 124 when the anvil 150 is coupled to the outer shaft "OS". The passage 158 is formed in part by an opening of the anvil 150 in the flange 154. It should be understood that in embodiments, one or more sensors (not explicitly shown) may be disposed in or on the head 152 of the anvil 150, similar to the sensor "S" disposed in or on the head 148 of the piston 138.

[0042] The drive screw shaft 120, the center drive 124, or any other component operatively coupled thereto may be coupled to one or more encoders (not explicitly shown), such as longitudinal or rotary encoders disposed along the inner shaft "IS" and / or the outer shaft "OS." Figure 12 The controller 300 is further described to communicate electronically (e.g., wired and / or wirelessly). The encoder can transmit received position data indicating the longitudinal or rotational distance traveled by the drive screw shaft 120 and / or the central drive 124. In embodiments, a longitudinal encoder (not explicitly shown) can be coupled to the central drive 124, an inner portion of the outer shaft "OS," and / or various portions of the piston 138 to measure the longitudinal movement of the piston 138 relative to the tissue characteristic sensing device 100.

[0043] Figure 5 and Figure 6 The tissue property sensing device 100 is shown in an open configuration. To transition the tissue property sensing device 100 to the open configuration, the drive screw shaft 120 is rotated in a first direction (e.g., clockwise or counterclockwise), thereby causing the threads 122 of the drive screw shaft 120 to exert a force on the threads of the central driver 124 and advance the central driver 124 along the drive screw shaft 120 within the outer shaft "OS." As the central driver 124 advances, it contacts the distal piston arm 144 and advances the piston 138, causing the head 148 of the piston 138 and the anvil 150 to move to an open position spaced apart from each other. Once the piston 138 moves away from the anvil 150, the target tissue (e.g., a portion of the intestine or other tissue within a patient's body) can be located between the proximal portion of the head 148 and the anvil 150. As the piston 138 moves within the outer shaft "OS," the indicator 142 moves out of alignment with the window 162 of the outer shaft "OS."

[0044] Figure 7 and Figure 8 The tissue property sensing device 100 is shown in the close configuration. To transition the tissue property sensing device 100 to the close configuration, the drive screw shaft 120 is rotated in a second direction different from the first direction, causing the threads 122 of the drive screw shaft 120 to apply a force to the threads of the center driver 124 and retracting the center driver 124 relative to the drive screw shaft 120 into the outer shaft "OS". Once retracted, the tension spring 160 applies a known force proximally and distally on the piston 138. In response to the pull of the center driver 124 on the tension spring 160, the tension spring 160 applies forces proximally and distally to push the piston 138 and the inner shaft "IS", respectively, toward each other. As shown Figure 8As shown, in embodiments, indicator 142 may become visible once center driver 124 is advanced proximally beyond a predetermined position. Based on the position of piston 138 relative to center driver 124, the distance that tension spring 160 has expanded can be calculated. The tension applied by tension spring 160 can then be calculated based on the known spring constant associated with tension spring 160 and the expansion distance. In embodiments, the compressive force on tissue compressed between anvil 150 and head 148 of piston 138 can also be determined by dividing the calculated tension in spring 160 by the area formed by the compression surface of anvil 150.

[0045] Now refer to Figure 9 and Figure 10 , the tissue property sensing device 100 is shown in an intermediate configuration. To transition the tissue property sensing device 100 to the intermediate configuration, the drive screw shaft 120 is rotated in a first direction, thereby advancing the central drive 124 within the outer shaft "OS". Figure 11 A handheld device is shown, which is configured to be connected to a tissue characteristic sensing device 100 ( Figure 1 ) and is generally designated 200. The handheld device 200 includes a housing 202 having a handle portion 202a and a connecting portion 202b. The connecting portion 202b is configured to selectively couple to the adapter assembly 102. More specifically, the connecting portion 202b has a recess 204 that extends proximally and inwardly to a proximal connecting surface 206. The connecting portion 202b of the handheld device 200 also includes electrical contacts 212 that extend distally from the proximal connecting surface 206 and are configured to mate with electrical contacts (not explicitly shown) located on the adapter assembly 102. The connecting portion 202b of the handheld device 200 includes a drive screw 208 that is configured to rotate and mate with one or more proximal connector sleeves 108 located on the adapter assembly 102 as described above. When the electrical contacts 212 are operably coupled to the housing 104 of the tissue property sensing device 100, the electrical contacts 212 are configured to transmit electrical signals to and from components of the tissue property sensing device 100, including one or more sensors "S" disposed along the head 148 of the piston 138 and one or more encoders (not explicitly shown) disposed along various components of the tissue property sensing device 100. For a detailed description of the handheld device, reference may be made to U.S. Patent Application Publication No. 2016 / 0310134, filed on April 12, 2016, entitled "HANDHELD ELECTROMECHANICAL SURGICAL SYSTEM," the contents of which are incorporated herein by reference in their entirety.

[0046] Figure 12 1 is a schematic diagram of a computing device that can be configured for operation of the tissue characteristic sensing device 100 and is generally represented as a controller 300. Although not explicitly shown in the drawings of this application, the controller 300 or one or more of its components can represent one or more components (e.g., input interface, output interface, etc.) of the tissue characteristic sensing device 100. In addition, the controller 300 can include one or more processors 302, memory 304, input interface 310, output interface 312, wireless interface 314, or any desired subset of their components.

[0047] The memory 304 includes a non-transitory computer-readable storage medium for storing data and / or software, including instructions that can be executed by the one or more processors 302. The instructions, when executed, can cause the processor 302 to control the operation of the controller 300, for example, to receive and transmit signals from one or more sensors "S" positioned along the head 148 of the piston 138 and from the first drive screw 208 ( Figure 11) and an associated motor (not explicitly shown). More specifically, the controller 300 may receive sensor signals indicating one or more light amplitude measurements and store the sensor signals in a memory 304 of the controller 300. The sensor signals indicating the light amplitude measurements may be stored along with supplemental information, including, but not limited to, timestamp information associated with the receipt of the signal, device information associated with the device receiving the sensor signal (e.g., encoder measurements), and the like. In an embodiment, the memory 304 includes a non-transitory computer-readable storage medium for storing data and / or software, including instructions that can be executed by one or more processors 302. The memory 304 may include one or more solid-state storage devices, such as flash memory chips. Additionally or alternatively, the memory 304 may include one or more mass storage devices that communicate with the processor 302 via a mass storage controller and a communication bus (not shown). Although the description of computer-readable media described in this disclosure refers to solid-state storage devices, it will be understood by those skilled in the art that computer-readable media may include any available media that can be accessed by the processor 302. More specifically, computer-readable storage media may include, but are not limited to, non-transitory, volatile, non-volatile, removable, non-removable media implemented in any technology for storing information, such as computer-readable instructions, data structures, program modules, or other suitable data access and management systems. Examples of computer-readable storage media include RAM, ROM, EPROM, EEPROM, flash memory or other known solid-state memory technologies, CD-ROM, DVD, Blu-ray or other such optical storage devices, magnetic cassettes, magnetic tape, magnetic disk storage devices or other magnetic storage devices, or any other medium that can be used to store information and that can be accessed by the computing device 300.

[0048] In an embodiment, the memory 304 stores data 306 and / or one or more applications 308. Such applications 308 may include instructions executed on the one or more processors 302 of the controller 300. The applications 308 may include instructions for causing the input interface 310 and / or the output interface 312 to receive sensor signals from the tissue characteristic sensing device 100 and / or the handheld device 200 and transmit sensor signals thereto, respectively. More specifically, when at least one sensor "S" (see Figure 1) detects one or more of the tissue characteristics discussed above, in response, at least one sensor "S" may transmit a signal indicative of the measurement value to the input interface 310. Once received by the input interface 310, the signal transmitted by the one or more sensors "S" may be stored in at least one memory 304 of the controller 300. Additionally or alternatively, the controller 300 may transmit the signal via the output interface 312 for analysis and / or display. For example, the output interface 312 may transmit the sensor signal to a display device (not explicitly shown) disposed on the tissue characteristic sensing device 100, the handheld device 200, or a display remotely located relative to the tissue characteristic sensing device 100. The memory 304 may also transmit and / or receive data via the wireless interface 314 through one or more wireless configurations, such as radio frequency, optical, Wi-Fi, Bluetooth (an open wireless protocol for exchanging data from fixed and mobile devices over a short distance using short-length radio waves to create a personal area network (PAN); (The IEEE 802.15.4-2003 standard for wireless personal area networks (WPANs) is based on the specification of a set of high-level communication protocols using small, low-power digital radios.) Although depicted as a separate component, wireless interface 314 may be integrated into input interface 310 and / or output interface 312 .

[0049] refer to Figure 13A , a flowchart associated with a method of measuring one or more tissue properties using a tissue property sensing device is shown and is generally referred to as process 400.

[0050] Initially, the tissue property sensing device 100 is engaged by a clinician or by default instructions stored in the memory 304 to transition the tissue property sensing device 100 to the open configuration (block 402; see Figure 5 This can be done before or after the tissue property sensing device 100 is inserted into the patient. To transition the tissue property sensing device 100 to the open configuration, the clinician can engage one or more input buttons (not explicitly labeled) on the handheld device 200. In response to the input, the controller 300 can receive and analyze the signal and, based on the analysis, cause the motor of the handheld device 200 to engage the one or more proximal connector sleeves 108 by rotating the one or more drive screws 208. Once the piston advances to the desired position ( Figure 5) (e.g., advanced to the open configuration), the handheld device 200 prevents further rotation of the drive screw 208. It should be understood that in embodiments, the memory 304 can cause the tissue property sensing device 100 to transition to the closed configuration before the distal portion of the tissue property sensing device 100 is inserted into the patient's body. This is done to collapse the piston or otherwise prevent the piston from engaging or grabbing tissue during the insertion process, as well as for calibration of the tissue property sensing device 100 (e.g., calibrating to zero or otherwise initializing initial position measurements collected from one or more encoders positioned around the tissue property sensing device 100).

[0051] Once the tissue property sensing device 100 is inserted into the patient, the target tissue "T" is positioned between the head 148 of the piston 138 and the head 152 of the anvil 150 (block 404). Next, the clinician engages the handheld device 200 to transition the sensing assembly to the proximal configuration (see FIG. Figure 7 ) (block 406). Specifically, the clinician engages one or more buttons on the handheld device 200 to retract the piston 138 to the proximal-most position. As the piston 138 moves proximally, the controller 300 may receive sensor measurements from one or more encoders to determine the position of the piston 138 relative to the central driver 124 (e.g., a component associated with the one or more encoders that remains stationary as the central driver 124 and the piston 138 move proximally or distally). When the controller 300 determines that the piston 138 is not in the retracted position (block 408), the controller 300 continues to move the piston 138 proximally to compress the tissue "T". Otherwise, once the controller 300 determines that the piston 138 is in the retracted position, the controller 300 prepares for the tissue property sensing phase. The retracted position can be any predetermined position or range of positions of the piston 138 and / or central driver 124 relative to a fixed component of the tissue property sensing device (e.g., the inner shaft "IS" or the outer shaft "OS") and can vary depending on the thickness of the tissue "T".

[0052] Once in the retracted position (e.g., the closed configuration), the thickness of the tissue "T" can be determined. For example, a clinician can observe the multiple indicators 142 through a window 162 in the outer shaft "OS" and, based on the visible indicators, determine the thickness of the tissue between the head 148 of the piston 138 and the head 152 of the anvil 150. In embodiments, the controller 300 can determine tissue thickness based on measurements received by one or more encoders positioned around the tissue property sensing device 100. In addition to tissue thickness, the initial pressure applied by the sensing assembly to the target tissue "T" can also be determined. For example, based on received sensor signals indicating the position of the piston 138 relative to the central driver 124, the known spring constant of the tension spring 160, and the surface area of ​​the head 148 of the piston 138 and the head 152 of the anvil 150, the controller 300 can determine the initial pressure applied by the sensing assembly when the tissue property sensing device 100 is in the approximated configuration. It should be understood that the tension spring 160 can be selected such that, when in the approximated configuration, the sensing assembly applies a known pressure to occlude blood flow to the tissue "T." Confirmation of blood flow obstruction may be determined by the controller 300 based on one or more sensor measurements measured by the sensor "S" (eg, one or more light amplitude measurements being within a predetermined range).

[0053] To determine systolic pressure, the controller 300 may cause the motor of the handheld device 200 to rotate the one or more drive screws 208 to move the central drive 124 distally toward the neutral position until blood begins to flow within the tissue (block 410; see Figure 9 Based on the measured distance that the piston 138 and / or central driver 124 are moved distally relative to one or more fixed components of the tissue property sensing device 100, the spring constant of the tension spring 160, and the surface area of ​​the head 148 of the piston 138 and the head 152 of the anvil 150, the controller 300 determines the pressure applied by the sensing assembly on the target tissue "T" when blood within the tissue begins to flow again (block 414). Based on this determination, the blood pressure can be determined. If the controller 300 determines that blood flow to the target tissue "T" is still completely blocked ("yes" at block 416) (e.g., the light amplitude measurement sensed by the sensor "S" does not exceed the predetermined measurement value), the central driver 124 moves distally (block 410) until blood begins to flow again in the tissue "T".

[0054] Similar to blocks 410 through 416, the tissue property sensing device 100 can move the central actuator 124 and the piston 138 to determine the patient's diastolic pressure at the target tissue. To measure the diastolic pressure after measuring the systolic pressure, the controller 300 continues to advance the central actuator 124 and the piston 138 until blood flow is fully restored within the tissue "T" (block 420). When this occurs, the pressure applied to the target tissue "T" can be determined as described above. This pressure corresponds to the patient's diastolic pressure obtained at the target tissue (e.g., the light amplitude measurement value can be consistently greater than a predetermined light amplitude measurement value threshold, indicating that blood flow has fully returned to the target tissue (block 428)).

[0055] Once the desired blood pressure (systolic, diastolic, or both) is determined, the controller 300 can transition the tissue property sensing device 100 to the open configuration. This can be accomplished by engaging the motor of the handheld device 200 to rotate the one or more drive screws 208 and advance the central drive 124 to the proximal-most position (e.g., the open configuration). Once the tissue is removed from the sensing assembly, the tissue property sensing device 100 can be positioned around the target tissue and the process 400 can be repeated to determine the systolic and / or diastolic pressure at the target tissue.

[0056] In an embodiment, when it is desired to remove the inserted portion of the tissue property sensing device 100 from the patient's body, the tissue property sensing device 100 can be transformed into a close configuration for removal. To this end, the controller 300 can cause the motor of the handheld device 200 to rotatably engage the proximal connector sleeve 108, thereby moving the central drive proximally. Specifically, the controller 300 can receive manual input from the clinician (e.g., by determining that one or more input buttons are engaged) and engage the motor in response. Once the head 148 of the piston 138 is flush with the head 152 of the anvil 150, the tissue property sensing device 100 can be removed from the patient's body.

[0057] It should be understood that various modifications may be made to the embodiments disclosed herein. In embodiments, the sensor may be positioned on any suitable portion of the robotic arm. Therefore, the above description should not be construed as limiting, but merely as examples of various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the appended claims.

Claims

1. A tissue property sensing system, comprising: an adapter assembly, the adapter assembly comprising a drive interface; a drive screw coupled to the drive interface and extending from the adapter assembly; as well as a sensing assembly capable of moving along the drive screw, the sensing assembly comprising: external axis; an anvil supported on a distal portion of the outer shaft; a central drive movable within the outer shaft and defining a longitudinal bore; a piston movable within the outer shaft and comprising a distal arm having a distal portion and a head extending from the distal portion of the distal arm, the piston movable within the outer shaft to move the head relative to the anvil between an open configuration and a closed configuration, wherein in the closed configuration the head of the piston and the anvil are positioned to clamp tissue and occlude blood flow in the tissue; one or more sensors configured to sense one or more of the tissue characteristics; and a tension spring coupled to the center driver and the piston to urge the piston toward the center driver and the head of the piston toward the anvil, wherein at least a portion of the tension spring is disposed within the longitudinal bore of the central driver, The central driver supports a fixed pin disposed within the longitudinal bore, the tension spring being coupled to the fixed pin.

2. The tissue property sensing system of claim 1, wherein the head of the piston supports at least one sensor.

3. The tissue property sensing system of claim 1 , wherein the piston includes a proximal arm and the central drive includes a housing, the proximal arm being housed within the housing to prevent the piston from rotatably moving relative to the central drive.

4. A tissue characteristic sensing system according to claim 1, wherein the central drive includes a threaded opening and a portion of the drive screw is accommodated within the threaded opening, so that rotation of the drive screw relative to the central drive causes the central drive to move longitudinally within the outer shaft.

5. A tissue characteristic sensing system according to claim 4, wherein rotation of the drive screw in a first direction causes the central drive to advance distally relative to the adapter assembly, and rotation of the drive screw in a second direction causes the central drive to advance proximally relative to the adapter assembly.

6. The tissue property sensing system of claim 2, wherein in the closed configuration, the sensing assembly applies a predetermined range of forces to tissue disposed within the sensing assembly.

7. A tissue property sensing system according to claim 3, wherein the outer shaft defines a window and the proximal arm of the piston supports a plurality of indicators, one or more of the plurality of indicators being visible through the window in the closed configuration to indicate the thickness of the tissue located between the head of the piston and the anvil.

8. The tissue property sensing system of claim 1, wherein a sensor is disposed on one of the head of the piston and the anvil.

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