Control unit for a medical device

A control unit for a medical instrument is provided. The control unit includes a housing having a curved top surface capable of accommodating a hand of the user, the housing being attachable to the medical instrument. The control unit further includes a first interface engageable by a purlicue of the hand for controlling a first function of the medical instrument and a second interface engageable by one or more fingers of the hand for operating at least a second function of the medical instrument.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to a control unit for a medical device and, more particularly, to a control unit and integrated user interface which enable translation of natural hand movements to an attached medical tool such as a laparoscopic tool to thereby enable precise and fine control over the position and function of the medical device.

Medical devices such as endoscopes and catheters are widely used in minimally invasive surgery for viewing or treating organs, cavities, passageways, and tissues. Generally, such devices include an elongated device body which is designed for delivering and positioning a distally-mounted instrument (e.g. scalpel, grasper or camera/camera lens) within a body cavity, vessel or tissue.

Since such devices are delivered through a delivery port which is positioned through a small incision made in the tissue wall (e.g. abdominal wall), and are utilized in an anatomically constrained space, it is desirable that the medical device or at least a portion thereof be steerable, or maneuverable inside the body using controls positioned outside the body (at the proximal end of the medical device). Such steering enables an operator to guide the device within the body and accurately position the distally-mounted instrument at an anatomical landmark.

Various interfaces for endoscopic instruments have been described in the prior art, see, for example, U.S. Patent Application Nos. 2008/0255420 and 2012/0041450 and U.S. Pat. No. 7,572,253.

However, there remains a need for a control unit having an interface that allows the surgeon to easily and intuitively maneuver and control an attached surgical tool.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided a control unit for a medical instrument, the control unit comprising: (a) a housing having a curved top surface capable of accommodating a hand of the user, the housing being attachable to the medical instrument; (b) a first interface rotatably attached to an end of the housing, the first interface being engageable by a purlicue of the hand and being for controlling a first function of the medical instrument; (c) a restraint element attached to the first interface and being capable of rotating therewith, the restraint element being for applying force to a back of the hand when positioned over the curved top surface; and (d) a second interface being attached to the first interface and being engageable by one or more fingers of the hand, the second interface being for operating at least a second function of the medical instrument.

According to further features in preferred embodiments of the invention described below, the control unit further comprising a drive unit.

According to still further features in the described preferred embodiments the drive unit is detachable from the housing.

According to still further features in the described preferred embodiments the drive unit includes at least one motor and a power source for enabling the first interface and the second interface to separately operate the medical instrument.

According to still further features in the described preferred embodiments the second interface includes levers simultaneously operable via thumb and index finger of the hand.

According to still further features in the described preferred embodiments the medical instrument is an articulating laparoscope having a grasper and further wherein the first interface controls articulation of the laparoscope.

According to still further features in the described preferred embodiments the second interface controls the grasper.

According to still further features in the described preferred embodiments the second interface controls opening and closing and rotation of the grasper.

According to still further features in the described preferred embodiments the control unit further comprising a user-engageable switch for activating/deactivating the first interface and/or the second interface.

According to another aspect of the present invention there is provided medical device comprising: (a) a control unit including: (i) a housing having a curved top surface capable of accommodating a hand of the user; (ii) a first interface rotatably attached to an end of the housing, the first interface being engageable by a purlicue of the hand; (iii) a restraint element attached to the first interface and being capable of rotating therewith, the restraint element being for applying force to a back of the hand when positioned over the curved top surface; and (iv) a second interface being attached to the first interface and being engageable by one or more fingers of the hand; and (b) a medical instrument attached to the housing and being operable via the first interface and the second interface.

According to still further features in the described preferred embodiments the medical device further comprising a drive unit.

According to still further features in the described preferred embodiments the drive unit is detachable from the housing.

According to still further features in the described preferred embodiments the drive unit includes at least one motor and a power source.

According to still further features in the described preferred embodiments the at least one motor engages a drive interface for the medical instrument when the drive unit is attached to the housing.

According to still further features in the described preferred embodiments the drive unit electrically communicates with the first interface and the second interface when the drive unit is attached to the housing.

According to still further features in the described preferred embodiments the second interface includes levers simultaneously operable via thumb and index finger of the hand.

According to still further features in the described preferred embodiments the medical instrument is an articulating laparoscope having a grasper and further wherein the first interface controls articulation of the laparoscope.

According to still further features in the described preferred embodiments the second interface controls the grasper.

According to still further features in the described preferred embodiments the second interface controls opening and closing and rotation of the grasper.

According to still further features in the described preferred embodiments the medical device further comprising a user-engageable switch for activating/deactivating the first interface and/or the second interface.

The present invention successfully addresses the shortcomings of the presently known configurations by providing a control unit for a medical instrument. The control unit includes a user interface that enables a user to simultaneously control the movement and actuation of, for example, a laparoscope using a single hand.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is of a control unit which can be used to maneuver and operate an attached medical instrument. The control unit includes an interface which can be used to control the movement, position and function of an attached medical instrument such as a laparoscope.

In laparoscopic surgery, a surgeon has to position the distal end portion (including a tissue manipulating end, e.g., grasper) of a medical instrument such as a laparoscope within a body cavity (e.g. abdominal cavity) and adjacent to treated tissue. In order to correctly position the laparoscope, the surgeon has to spatially orient the entire laparoscope while controlling deflection of the steerable portion and actuating the tissue manipulating end.

A surgeon typically uses an interface (graspable handle and lever) of a surgical tool for positioning, maneuvering, holding and operating the device and effector end at the tissue site of interest. While presently used device interfaces can provide such functionality, they can be limited by a tradeoff between maneuverability and operability of the entire device and its effector end (instrument mounted on a distal end of a laparoscope shaft) or limited by a steep learning curve thus requiring considerable time and effort on the part of the surgeon to complete a minimally invasive treatment procedure.

Experiments conducted by the present inventors demonstrated that an interface that provides single hand control over all of the functions of a medical instrument such as a laparoscope is typically difficult to master due to the complexity of movements and the number of interfaces. The present inventors set out to design a single hand control unit that is easy to master and provides the functions most needed by surgeons. As is further describes hereinunder, the present inventors devised a miniature, light weight motorized control unit with intuitive interfaces that enable a surgeon to easily maneuver and operate an attached medical instrument such as a laparoscope using a single hand.

Thus, according to one aspect of the present invention there is provided a control unit for a medical instrument.

As used herein, the phrase “medical instrument” refers to any instrument used in an internal or external procedure (e.g. surgery). The medical instrument can be a laparoscope fitted with a grasping tool, cutting tool and the like, an endoscope fitted with a camera and/or delivery/suction channels or a catheter, cannula and the like.

The user interface of the present invention is particularly suitable for use with a laparoscope having a steerable (deflectable) distal portion and a distally-mounted instrument such as a grasper or cutter.

Laparoscopes are widely used in minimally invasive surgery for viewing or treating organs, cavities, passageways, and tissues. Generally, such devices include an elongated device body which is designed for delivering and positioning a distally-mounted instrument (e.g. scalpel, grasper or camera/camera lens) within a body cavity, vessel or tissue.

Since such devices are delivered though a delivery port which is positioned through a small incision made in the tissue wall (e.g. abdominal wall), and are utilized in an anatomically constrained space (within, for example, the abdominal cavity), it is desirable that the medical device or at least a portion thereof be steerable, or maneuverable inside the body using controls positioned outside the body (at the proximal end of the medical device). Such steering enables an operator to guide the device within the body and accurately position the distally-mounted instrument at an anatomical landmark.

Deflection of the steerable portion is typically effected via one or more control wires which run along the shaft of the device to the distal end of the steerable portion.

The proximal end of each control wire can be connected to the control unit such that pulling of the wire bends the device shaft and deflects the steerable portion with relation to the pulled wire.

The device effector end (distally-mounted instrument) is controlled via one or more additional wires which are similarly connected to the control unit and actuated by the user interface. Thus, the control unit of a steerable device such as a steerable laparoscope provides three separate functions, positioning of the device shaft with respect to the tissue access site (up/down right/left in/out, angle) deflection of the steerable portion, and actuation of the distally mounted instrument in the case of grasper, open/close and rotation of the jaws.

The control unit of the present invention includes a housing having a curved top surface for accommodating a portion of the palm of a hand of the user. The housing contains electronic circuitry for transferring user control actions to a drive unit and a drive mechanism (gears, levers, shafts, wires, belts etc) for transferring a driving force from the drive unit to an attached medical instrument.

The electronic circuitry translates in real time (via a microcontroller) the hand/finger movements of the surgeon to commands for motors/actuators of the drive unit. The motors/actuators then drive the attached medical instrument functions through the drive mechanism.

The control unit further includes a first interface which is rotatably attached to an end of the housing (also referred to herein as the ‘front end’). The first interface is engageable by a purlicue of the hand (the palm-side cleft between the thumb and index finger) and is designed for controlling a first function of the medical instrument.

The control unit optionally further includes a restraint element which is attached to the first interface such that it rotates therewith. The restraint element is designed for applying a force to a back of the hand when the hand is positioned over the curved top surface of the housing.

The control unit further includes a second interface which is attached to the first interface. The second interface is engageable by one or more fingers of the hand (e.g. thumb and index finger) and is designed for operating at least a second function of the medical instrument.

The user interface of the present control unit provides single hand control over an attached medical instrument in the following manner:

(i) the shaft of the medical device can be moved in and out, up and down and side to side with respect to, for example, a tissue access site via hand and arm movement (primarily by flexing/extending the wrist and elbow joints and rotating the shoulder joint);

(ii) a steerable portion of the shaft can be deflected by tilting (rotating side to side) the first interface (primarily by rotating the wrist join); and

(iii) a distally mounted tissue manipulating end can be actuated (open/close and rotation) via finger movement (primarily about the inter-phalangeal joints and the metacarpal-phalangeal joints).

The present control unit provides several advantages when used to position and operate a medical instrument such as a steerable laparoscope:

(i) greater and more natural maneuverability—a laparoscope can be operated using less effort and without requiring extreme maneuvering of body and limbs;

(ii) simultaneous control over three functions—laparoscope spatial positioning, shaft steering and effector end actuation;

(iii) single hand operation—all movements are controlled via a single hand using three interface regions, the palm/dorsum, purlicue and fingers;

(iv) compact and intuitive interface with instinctive operational controls that are easy to master; and

(v) can be used to control any attached/integrated medical instrument.

Referring now to the drawings,FIG. 1Aillustrates the present control unit which is referred to herein as control unit10.

FIG. 1Aillustrate control unit10having housing330with a curved top surface331designed for accommodating a palm portion of a hand (shown inFIG. 1B). A medical instrument30is shown attached to housing330via coupler320positioned at a bottom side of housing330. Medical instrument30can include diathermia functions provided from electrical plug318.

Housing330(and interfaces100and150described below) can be fabricated from a polymer and/or alloy using machining, 3D printing and/or casting/molding fabrication approaches. Housing330can be 10-40 mm wide, 10-40 mm deep and about 60-100 mm in height. Curved top portion331can have a radius of curvature of 10-60 mm.

First interface150(also referred to herein as interface150) is rotatably attached to a front end of housing330and is capable of tilting side to side. Interface150is designed to be engaged by a purlicue of a hand (shown inFIG. 1B) such that rotation of the wrist joint side to side tilts first interface through an arc of 60-120 degrees. A dorsum retaining element200is attached to first interface150and rotates therewith and is designed for restraining the palm portion against curved top surface331of housing330.

Tilting of interface150to one side results in corresponding deflection of articulation308of medical instrument30(laparoscope shaft310shown with grasper302). Control unit10can be designed such that the degree of deflection of articulation308can directly correspond to the degree of tilting of first interface150or to increase/decrease the degree of deflection with respect to the degree of tilting.

Control unit10further includes second interface100(also referred to herein as interface100) which is engageable by a thumb and index finger portions of a user (shown inFIG. 1B). Interface100is attached to interface150and rotates therewith. Interface100can actuate tissue effector end such as grasper302to open and close by opening and closing the thumb and index finger.

Control unit10includes a drive mechanism which is attachable to control wires running the length of shaft310of medical device30. The drive mechanism actuates the wires that in turn actuate shaft deflection and grasper opening closing and rotation.

The drive mechanism can be manually driven (e.g. directly connected to interfaces100and150via levers) or it can be driven by a drive unit500removably attachable to housing330. Drive unit500includes a motor/actuator and power source (battery) and can be reused by fitting a sterilizable cover600around it. Housing330, interfaces100and150as well as attached medical instrument30can be disposable.

Cover600(FIG. 1C) is fabricated from a sterilizable elastic material such as PC, ABS, PC/ABS and/or Thermoset photo polymer. Once sterilized, cover600is carefully fitted over drive unit500without allowing drive unit500to contact external surfaces of cover600. The covered drive unit500is then coupled to housing330of control unit10and cover600is secured to housing300via releasable connectors such as snaps, buttons, hooks or the like. Cover600isolates the exposed parts of drive unit500from the environment allowing safe use in the operating room without fear of contamination.

To disassemble control unit10, a user simply releases the connectors allowing cover600and drive unit500to be removed from housing330. Drive unit500can then be removed from cover600and be reused with another sterile cover in another procedure.

Drive unit500can include a motor pack, a control unit composed mainly of electrical circuits, a battery pack and optional screen, speaker and buttons for user control and feedback. The shaft(s) of the motor pack engages drive ends505,506,507which protrude out of housing530.

FIG. 1Dillustrates the mechanical interface between housing330and drive unit500. Sockets305,306,307, which form a part of a drive mechanism of housing330, are shown at the rear face of housing330. Drive shaft ends505,506,507protruding out of housing530of the drive unit500engage sockets305,306,307of the drive mechanism when drive unit500is coupled to housing330.

Shaft110of the flexible drive shaft of finger interface mechanism, engages socket510of drive unit500. Shaft110is connected to finger interface100and transfers movement at finger interface100(i.e. open/close and rotation) to sensors of a control unit of drive unit500for operating the motor pack. When drive unit500is connected to housing330, electrical contacts115and515of the drive unit500transmit signals from mode button312(shown inFIG. 1C) to drive unit500.

FIG. 2Aillustrates the drive mechanism within lumen350of housing330. Interface100is connected to a front end of interface150via tube92and nut90. Flexible shaft101is connected at its front end to interface100and runs through tube92and tube364at the rear side of the drive mechanism. Shaft head110is connected to flexible shaft101. Cables361,362and pulley360rotate with shaft364, resulting in deflection of a steerable portion of a shaft of an attached medical device.

Restraining element200is connected at the front of interface150via a pivoting connector205. Interface150is connected to housing330via rotating surface151. Electric mode button312is placed at the bottom of interface150with wiring114connecting button312to contacts115.

FIG. 2Billustrate the drive mechanisms for articulating a steerable shaft and actuating a grasper.

At the top of housing330, hollow shaft364is fixed to pulley360and gear368and cable361is routed over pulleys365and367. Coupler320connects housing330to shaft310of medical instrument30(not shown). Gears340-342transmit rotation from one motor socket of drive unit500to a jaw rotation mechanism, while worm gear380transmits rotational movement from another motor socket to a jaw open/close mechanism. Lever329secures sterile cover600when drive unit500is coupled to housing330.

FIGS. 3A-Cillustrate in details the jaws rotation mechanism. Hexa-shaped nut334is fixed to shaft303. The hexa-shaped nut334slides freely up and down through opening323of gear335which is located at the bottom end of housing350; rotation of gear335rotates hexa-shaped nut334.

Gear335is rotated by worm gear333which is in turn rotated by spur gears331,332,333. Spur gear333and worm gear335are fixed onto the same shaft and rotate together; when shaft303rotates, jaws rotate as shown inFIG. 3C.

FIGS. 4A-Eillustrate in details the mechanism for actuating opening and closing of the jaws of medical device30grasper302. Hexa clamp390holds hexa nut334between upper part384and lower part385. At the clamping area between part384and385nut334is round and can rotate with respect to hexa clamp390, while allowing clamp390to move nut334forward and backward. Part384has an internal thread for accepting screw383which is fixed to gear382; rotation of gear382rotates screw383. Parts384and385have flat surfaces (identical to surface387). Portion350of housing330has internal flat surfaces353(shown inFIG. 3B) that match the flats surfaces of clamp390. These sliding flat surfaces353of housing350and387of clamp390do not allow clamp390to rotate. Thus, when screw384is rotated clamp390move back and forth according to direction of the rotation. When clamp390moves forward and backward it moves shaft303(FIG. 4E) resulting in opening/closing movement of the jaws.

FIGS. 5A-Billustrate in detail the pulley mechanism that articulates region308(FIG. 1A) of shaft310.

Gear369rotates gear368which is fixed to shaft364. Pulley360is also fixed to shaft364such that when gear368rotates, shaft364rotates along with pulley360. Cables361,362are connected to pulley360, thus when pulley360is rotated to one direction one cable is pulled and the other cable is released, resulting in deflection of element308(FIG. 5B).

FIGS. 6A-Dillustrate in detail drive unit500of control unit10.FIG. 6Ais a front view of drive unit500showing drive shaft ends505,506,507and rotation sensor head508protruding out of housing530of the drive unit500. Rotation sensor head508engages gear head308located at interface150to measure the rotation (tilt angle) of interface150. Socket591of sensors590engage interface100enabling measurement of finger movements. Touch screen560of drive unit500(located on the side of housing530) allows the user to get information about drive unit500mode of operation and battery status and to verify drive setting (speed etc) inputted by the user.

FIG. 6Bshows the rear side of drive unit500with on/off switch561.FIGS. 6C-Dshow front and rear views of the internal components of drive unit500. A battery pack552is located at the bottom of drive unit housing530. Battery pack552can include, for example, 4 CR123 type batteries arranged in 2 layers in battery pack housing550. Motors525,526,527(DC, brushless or steps type) are located on top of battery pack552and are connected to motors driver circuits (PCB)522. Control unit570is located above the motors unit and a sensor unit590is located between PCB's532and533which contain the electrical circuits for receiving and processing sensors signals (from interfaces and motors) to generate motor commend signals. PCB's532and533also include touchscreen and wireless communication components. PCB517contains 2 arced shape contacts that engage with contacts115of the interface.FIGS. 7A-Billustrate the interface between control unit10, medical instrument30and drive unit500. A portion of medical instrument30, housing330of the surgical tool, and a portion of interface150and housing530have been removed from these figures for clarity purposes. Interface100mechanically transfer finger opening/closing movement via flexible shaft101and interface150is purlicue-actuated rotational (tilt side to side) movement. Gear220is coupled to gear221which is fixed to interface150and thus, rotation of interface150rotates gear221. Gear220is fixed to shaft222and rotates with gear222. A socket308located at the distal end of shaft222can be engaged to rotate sensor head508of rotation sensor518with shaft222.

When the user tilts interface150(with purlicue motion), a scaled rotation movement is transferred to rotation sensor518. The signals from rotation sensor518are processed by the control unit of drive unit500into motor operation.

FIGS. 8A-Cillustrate in more details the tilt measuring mechanism of interface150. Gear220is coupled to gear221which is fixed to interface150via inner part of holding surface252. Tilting of interface150by the purlicue of a user's hand rotates gear221which transfers rotation to gear220(which is rotationally connected to housing330) to rotates shaft222(shown inFIGS. 8A-B). Interface150also includes central tube253of flexible shaft101that transfers interface100movements to control unit570located in housing530.

FIG. 8Dis a cut-away view of interface150showing the mechanism that transfers rotation of interface150through gear221(that rotates with interface150) to rotation sensor518of control unit570. When the user tilts interface150, a scaled rotation movement is transferred to rotation sensor518; the signals from rotation sensor518are processed by the control unit into operation of the motor of drive unit500.

FIGS. 9A-Dillustrate finger interface100of control unit10.FIGS. 9A-Billustrates shaft90and nut92which connect interface100to interface150. In order to use interface100simultaneously with interface150, the user places the purlicue of a hand on interface150and a thumb and index finger on levers161. Optional external wings162may be used to secure the thumb and index finger within levers161. The angle between a lever161and a wing162can be adjusted via hinge164.

FIGS. 9C-Dillustrate the internal mechanism of interface100. Inner levers161are fixed to brackets166which rotate around hinge165. Pin169of central shaft101is positioned through elongated holes167at the end of brackets166. Rotation of brackets166by inner levers161leads to linear movement of shaft101(through pin167). Spring91located on straight part109of shaft101between distal part of shaft90and the distal end181of shaft10, is stretched when the user applies a closing force on levers161. When this closing force is released spring91contracts linearly and shaft101returns to its original position.

FIGS. 10A-Eillustrate the connection between flexible shaft101operated by interface100and the movement sensors of control unit592of drive unit500. A magnet470is fixed to the end of flexible shaft101(FIGS. 10A-B). Connector518and a magnetic sensor471(FIG. 10E) are positioned parallel to the main plane of shaft469(FIGS. 10D-E). Sensor471which measures the linear movement of magnet470is sampled by control unit of drive unit500which is used to control the open-close movement and position of the jaws via motor.

As used herein the term “about” refers to ±10%.

Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following examples, which are not intended to be limiting.

EXAMPLES

Reference is now made to the following example, which together with the above descriptions, illustrate the invention in a non limiting fashion.

Interface Design Based on Manual Object-Picking Patterns

In a previously filed patent application (WO2015029041), Applicant disclosed a motorized articulated surgical tool having a user interface capable of measuring the orientation of a user's palm in three axis relative to the interface housing. Orientation measurements were translated into electrical signals and processed into command signals for actuating articulation of a medical device shaft and operation of an effector end thereof.

Following numerous studies conducted with the aforementioned user interface, the present inventors observed that while the interface of WO2015029041 was highly efficient in controlling an attached medical device, the learning period required to master this interface was relatively long for inexperienced users.

In order to substantially decrease the time required to master an interface for a surgical device, the present inventors studied users tasked with picking objects from a surface in an effort to decipher the patterns of movements used for such activity. A pencil was placed on a table surface and each subject in the study was instructed to place a hand over a pencil and pick it up as quickly as possible when hearing an audio signal. Of the15subjects tested, all demonstrated the pattern of picking up the pencil shown inFIG. 11A.

In order to pick the pencil the tested subjects rotated their palm to an orientation which is parallel to the table surface (left images) thus enabling their thumb and index finger to quickly clamp over the pencil (right images).

The results of this study indicated that in order to shorten the time needed to master control over a medical device, the user interface of the device must orient the user's hand such that the plane of the hand is perpendicular to the shaft of a medical instrument attached to the user interface and not allow the palm to roll or pitch with respect to the interface housing.

The lessons learned from this study were used to develop a user interface that measures purlicue and finger movements while restricting the palm of the user from moving with respect to the interface housing.

A prototype medical device (FIGS. 11B-C) was developed and tested on a group of users who were instructed to use the interface controls (first and second interfaces described hereinabove) in order to pickup objects from a table surface.

This test showed that eliminating palm movements with respect to the interface housing considerably shortened the time needed to achieve full control over device shaft articulation and effector end operation. Interestingly, following a time period of using this new interface, users adapted quicker to operating more complex interfaces such as the one described in WO2015029041.