Catheters with deployable instruments (e.g., needles) can damage tissue if the instrument unintentionally deploys during use. Described herein are devices and methods for controlling the position of a deployable catheter instrument. In one embodiment, a catheter can include an instrument slidably disposed within an inner lumen of the catheter and coupled to at least one protrusion, as well as a retraction stop coupled to the catheter. The catheter can further include a biasing element coupled to the instrument that can urge the instrument proximally such that the at least one protrusion abuts against the retraction stop, as well as an advancing mechanism to selectively engage the instrument and urge it distally. In some embodiments, the biasing element can be omitted and a deployment stop can be included distal to the retraction stop. These configurations can prevent unintentional instrument deployment and provide greater positioning precision during instrument deployment.

An injection device is described including a detection unit that includes an electrode that detects electrical characteristics of a biological tissue, a follow-up mechanism that follows motions of the biological tissue, and a puncture unit capable of puncturing the biological tissue. The injection device is configured to administer a predetermined substance to the biological tissue through a hollow portion defined in the puncture unit. A position of the puncture unit is specified based on a position of the electrode. The follow-up mechanism includes a spiral portion spirally extending around the puncture unit, and being stretchable and compressible along an extending direction of the puncture unit. Electrodes are disposed on an annular distal-end projected plane of the spiral portion, as seen from a distal end side of the puncture unit, along a circumferential direction of the puncture unit.

Provided is an endoscope sheath including: a sheath body having an elongated rotating section and a stationary section, which are coupled to each other in a relatively rotatable manner about a longitudinal axis; a first passage along the axis; a second passage parallel to the first passage; an outlet through which a proximal end of an injection needle inserted in the second passage is pulled outside, the outlet being capable of changing a pullout position of the proximal end of the needle relative to the stationary section in the circumferential direction; and holders provided in the stationary section and separated by intervals in the circumferential direction, each holder securing an injector having the needle to the stationary section at a position where the needle protrudes from the distal end of the body and releasing the injector at a position where the needle is accommodated inside the body.

A barbed microcatheter includes a hollow tube having an elongated lumen, outwardly projecting barbs, fluid egress openings, a tissue anchor secured to a proximal end of the hollow tube, and a needle secured to the distal end of the hollow tube. The needle is used to form a first tissue opening at the first end of the wound. The hollow tube is pulled through the first tissue opening until the tissue anchor abuts against tissue at the first end of the wound. The needle is used to form a second tissue opening at the second end of the wound. The hollow tube is pulled through the second tissue opening so that barbs engage wound tissue. After cutting away the needle, a therapeutic fluid is introduced into the elongated lumen and passes through the fluid egress openings for infusing the wound with the therapeutic fluid.

A catheter system includes: a catheter assembly that includes: an inner needle having a needle tip at a distal end thereof, a hollow needle hub fixed to a proximal end section of the inner needle, a catheter shaft into which the inner needle is inserted, and a catheter hub having the inner needle inserted thereinto, wherein the catheter hub is fixed to a proximal end section of the catheter shaft; and a catheter gripper that is attachable to and detachable from the catheter assembly, wherein the catheter gripper includes: a gripping member, and an attaching/detaching mechanism configured to attach and detach a proximal end section of the needle hub to and from a first end section of the gripping member.

Devices for transferring fluid to or from a subject include an extension tube assembly with an axially extending inner tube configured to couple to an elongate tubular cannula having opposing proximal and distal ends with an axially extending lumen and an axially extending inner tube. The inner tube extending through the tubular cannula defines an exposed needle tip and is in fluid communication with the inner tube of the extension tube assembly. The needle tip extends out of a distal end of the tubular cannula a suitable distance.

Disclosed embodiments relate to devices and related methods for delivering a composition to a subject. In some embodiments, a device may include a catheter coupled to a handle. The handle may include proximal and distal handle portions that are moveable relative to one another to selectively expose a needle at a distal end of the catheter. The proximal handle portion may include a container coupling and a grip extending proximally from the container coupling.

Ablation catheters and systems include catheter tips with a positioning element to ablate a target tissue that damages substantial cellular component in the target tissue while avoiding significant damage to the extra cellular matrix.

A wall of a catheter (a) includes a braided portion having an outer surface, an inner surface, and a braided interior between the outer and inner surfaces, and (b) is shaped to define first and second longitudinally-running channels therethrough. A distal portion of the catheter is shaped to define first and second lateral openings. An angle between (a) a first line running between the first and second lateral openings, and (b) a second line that is parallel to a central longitudinal axis of the catheter when the catheter is straight, is between 30 and 150 degrees. A flexible longitudinal member passes from a proximal portion of the catheter to the distal portion via the first channel, out of the first channel via the first lateral opening, into the second channel via the second lateral opening, and from the distal portion to the proximal portion via the second channel.

A delivery device for delivering an instrument through an intravenous catheter may include a housing, a rotary element disposed within the housing, and the instrument. In some embodiments, the rotary element may include a groove, which may extend around at least a portion of a circumference of the rotary element. In some embodiments, the instrument may be disposed within the groove and/or between the rotary element and the housing. In some embodiments, in response to rotation of the rotary element with respect to the housing, the instrument may be advanced distally through a port of the housing. In some embodiments, the instrument may include a guidewire, a probe, tubing, or a light tube.