A variable stiffness device includes a shape-memory unit formed of at least two hollow shape-memory members connected together. Each of the shape-memory members is transitionable in phase between a first phase in which the shape-memory member is in a low stiffness state and a second phase in which the shape-memory member is in a high stiffness state. The shape-memory member in the high stiffness state has a higher level of stiffness than in the low stiffness state. Hollow portions of the shape-memory members are connected together so that the shape-memory unit has a lumen-like inner space configured to allow fluid for cooling the shape-memory members to flow. The variable stiffness device also includes a heating member configured to heat the shape-memory members.

The present invention is directed to a tool having a wrist mechanism that provides pitch and yaw rotation in such a way that the tool has no singularity in roll, pitch, and yaw. In one embodiment, a minimally invasive surgical instrument includes an elongate shaft having a working end, a proximal end, and a shaft axis between the working end and the proximal end; and an end effector. A wrist member has a flexible tube including an axis extending through an interior surrounded by a wall. The wall of the flexible tube includes a plurality of lumens oriented generally parallel to the axis of the flexible tube. The wrist member has a proximal portion connected to the working end of the elongate shaft and a distal portion connected to the end effector. A plurality of actuation cables have distal portions connected to the end effector and extend from the distal portion through the lumens of the wall of the wrist member toward the elongate shaft to proximal portions which are actuatable to bend the wrist member in pitch rotation and yaw rotation.

A variable stiffness device includes a first elongated member in a hollow shape extending along a longitudinal axis, and a second elongated member including a heater, disposed inside an inner circumference of the first elongated member, and extending in parallel to the first elongated member along the longitudinal axis. The first elongated member includes a high bending stiffness portion and a low bending stiffness portion alternately aligned along the longitudinal axis. One of the first elongated member and the second elongated member includes a shape-memory pipe. The heater extends through an inner space of the shape-memory pipe and configured to heat the shape-memory pipe to increase stiffness of the shape-memory pipe.

An over-actuated system [304], such as a catheter, having shape memory alloy (SMA) hysteretic wire actuators is controlled using a controller [300, 302] that generates a control signal [310] based on a temperature model that takes into account physical limitations of the SMA hysteretic wire actuators, and based on a hysteresis model (e.g., the Duhem model) that describes hysteresis behavior of the SMA hysteretic wire actuators. The controller preferably includes a feedback controller [302] and a reference governor [300] that generates a smart reference signal [308] from a reference signal [306] representing a desired value of an output of the system. The smart reference signal preferably minimizes an error between the reference signal and an achievable output, and the control signal preferably is generated based on the smart reference signal.

A medical device may comprise a handle portion; an insertion portion having a proximal end portion at the handle portion, wherein the insertion portion includes a lumen therein and a distal end having a distal opening in communication with the lumen; and a member disposed within the lumen, the member having a distal end portion with an imaging device. The member may be configured to transition between a first configuration and a second configuration. In the first configuration, the imaging device may face distally, and, in the second configuration, the imaging device may face proximally. Extending the distal end portion of the member distally past the distal opening may cause the member to transition from the first configuration to the second configuration.

A rigidity variable apparatus includes: a rigidity variable member having a cylindrical shape, a bending rigidity of the rigidity variable member increasing by being heated; a heater having a cylindrical shape and arranged along the rigidity variable member on an inside of the rigidity variable member in a radial direction, the heater being configured to heat the rigidity variable member; a filler arranged so as to fill a gap between the heater and the rigidity variable member in the radial direction, the filler being configured to transfer heat from the heater to the rigidity variable member; and a tube arranged along the heater on an inside of the heater in the radial direction.

An insertion shaft for an electrically actuated scope includes at least two wires. Each wire has a proximal end anchored to a respective proximal anchoring point and a distal end anchored to a respective distal anchoring point. The wires are disposed around a central axis and extend along the insertion shaft. Each of the wires comprises two-way memory material configured to contract when heated to or above a first predetermined temperature and return to a predetermined original length thereof upon cooling to or below a second predetermined temperature below the first predetermined temperature. The length of each wire is larger than a length along the insertion shaft between the proximal anchoring point and the distal anchoring point to which the wire is anchored, such that each of the wires is incorporated in the insertion shaft with a predetermined slack.

An invasive medical device (10) is disclosed comprising a flexible sheath (11) enveloping at least one lumen (17, 17′) comprising an electrically conductive wire (20) including a deformable actuator (21) for deforming a section of the invasive medical device in response to an electric current provided through the electrically conductive wire, wherein the flexible sheath comprises a set of apertures (31) extending through the flexible sheath to the at least one lumen, said apertures being filled with an adhesive (33) anchoring the deformable actuator to the flexible sheath. A manufacturing method for such an invasive medical device (10) is also disclosed.

An apparatus for performing surgical procedures is disclosed including a flexible entry guide tube and a first steering device. The guide tube has one or more lumens extending along its length from a proximal end to substantially at or near a distal end. At least one of the one or more lumens is an instrument lumen with open ends to receive a flexible shaft of a surgical tool. The first steering device is insertable into the instrument lumen to shape the guide tube as it is inserted through an opening in a body and along a path towards a surgical site. The apparatus may further include a flexible locking device to couple to the flexible entry guide tube and selectively rigidize the guide tube to hold its shape. The guide tube may be steered by remote control with one or more actuators.

Apparatus described herein includes a tube, shaped to define a tube lumen and including a distal portion that has a plurality of articulated sections. The apparatus further includes a ribbon that passes longitudinally through the tube lumen and is connected to a distalmost one of the articulated sections, and a control handle disposed at a proximal end of the tube, the control handle being configured to flex the distal portion of the tube by pulling the ribbon. Other embodiments are also described.