A variable diameter tube for use in a vessel inserter for performing hemodynamics researches and related operations comprises two coupled different-characteristic materials which are coupled to one another to provide a single stretchable tube assembly.

A cannulation tool, systems, and methods for placing a cannula is provided. The tool includes a body and a plurality of tubes removably secured to the body. Each tube is moveable from a retracted position to an extended position. The plurality of tubes may include an inner tube, an outer tube, and a set of tubes positioned between the inner tube and the outer tube. Each tube of the set of tubes is nested in an adjacent tube, the outer tube is positioned external to the set of tubes, and the inner tube is positioned internal to the set of tubes. The tool also includes a gripper rod having a gripper disposed on an end thereof for forcibly moving each tube of the set of tubes, in sequence, from the retracted position to the extended position.

A catheter assembly may include a cannula. The cannula may include a distal tip, an elongated tubular shaft, and an inner lumen formed by the elongated tubular shaft. A first portion of the elongated tubular shaft may have a first outer diameter. The first portion may be proximate the distal tip. A second portion of the elongated tubular shaft may have a second outer diameter. The second outer diameter may be greater than the first outer diameter. The catheter assembly may also include a catheter adapter, which may include a catheter and a catheter hub. The second portion of the elongated tubular shaft may be at least partially disposed in the catheter hub.

A method of forming an access opening through a psoas muscle to a patient's spine includes laterally inserting a stimulating dilator into the psoas muscle. The stimulating dilator has a stimulation channel formed in an outer surface thereof. An electrical pulse is transmitted via an EMG into the stimulating dilator to locate a position of a nerve in the patient's psoas muscle. The stimulating dilator is laterally inserted through the psoas muscle and toward the patient's spine in a way that avoids the nerve. A stimulating probe is inserted into the stimulation channel along the outer surface of the stimulating dilator while transmitting an electrical pulse via the EMG into the stimulating probe to verify the position of the nerve.

An access sheath is provided. The access sheath comprises: an outer sheath extending in one direction and having a cavity formed along a longitudinal axis of the outer sheath; and an inner sheath arranged in the cavity of the outer sheath, and having a plurality of balloons configured to expand, wherein the outer sheath includes: an outer body formed of a first material; and an elastic connection part formed of a second material which is more flexible than the first material of the outer body, and wherein a diameter of the outer sheath increases by the elastic connection part which expands according to an expansion of the balloons.

A medical device includes an inner element and an outer element positioned at least in part around the inner element. At least one of the inner element and the outer element comprises compression-stiffening particles. The compression-stiffening particles are transitionable from a first state to a second state in response to application of pressure. The compression-stiffening particles have a higher rigidity in the second state than in the first state. The medical device also includes a pressure source operably coupled to one or both of the inner element and the outer element to apply pressure sufficient to transition the compression-stiffening particles from the first state to the second state.

A cannula system and method for accessing a blood mass in the brain. The system comprises a cannula with a camera mounted on the proximal end of the cannula with a view into the cannula lumen and the surgical field below the lumen. A prism, reflector or other suitable optical element is oriented between the camera and the lumen of the cannula to afford the camera a view into the cannula while minimizing obstruction of the lumen. The system may also include an obturator with a small diameter shaft and a large diameter tip which is optically transmissive, so that a surgeon inserting or manipulating the assembly can easily see that the obturator tip is near brain tissue (which is white) or blood (which is red).

A pacemaker lead for cerclage pacing includes a lead fixing part including a fixing tip whose diameter becomes gradually smaller toward an end of a distal part thereof, a plurality of bipolar electrodes that come into close contact with heart muscle, in an outer circumference of the lead fixing part, and a guide wire insertion through hole through which a guide wire can be inserted thereinto, a lead body part configured to be extended to the lead fixing part, having a stylet insertion through hole formed therein, and a body fixing part formed in a bent shape so as to be fixed to an inner wall of the coronary sinus, and a stylet inserted into the stylet insertion through hole, enabling the pacemaker lead for cerclage pacing to be easily moved within the body of the patient.

A method of forming an access opening through a psoas muscle to a patient's spine includes laterally inserting a stimulating dilator into the psoas muscle. The stimulating dilator has a stimulation channel formed in an outer surface thereof. An electrical pulse is transmitted into the stimulating dilator to locate a position of a nerve in the patient's psoas muscle. The stimulating dilator is laterally inserted through the psoas muscle and toward the patient's spine in a way that avoids the nerve. A stimulating probe is inserted into the stimulation channel along the outer surface of the stimulating dilator while transmitting an electrical pulse into the stimulating probe to verify the position of the nerve.

The use of stepped cannulas, wherein a step structure creates a backstop to reduce backflow along the cannula body, is known for convection enhanced delivery of agents to the brain and other structures within an animal. Described herein are novel and improved stepped cannula designs wherein the length of the cannula segment between the step and the dispensing outlet is variable and can be controllably adjusted inside the patient during delivery. This advantageously allows the operator to place the cannula step at the optimal position and deliver agents at one or more positions within the target structure.