Systems and methods are provided for injecting one or more agents into tissue within a patient's body. In one embodiment, an injection device includes a substantially axially incompressible elongate member including a lumen extending between proximal and distal ends thereof. A distal stop is provided on the distal end and a needle tip extends distally beyond the distal stop, the needle tip having a cross-section smaller than the distal end. The needle tip includes a passage communicating between the lumen and an outlet in the distal tip that has having a cross-section smaller than the lumen. In an exemplary embodiment, the elongate member includes a coil extending between the proximal and distal ends, and a sleeve disposed within an interior region of the coil extending between the proximal and distal ends. The sleeve defines the lumen and may be free-floating within at least a portion of the coil.

A wall (39) of a catheter (38) (a) includes a braided portion (41) having an outer surface (45), an inner surface (47), and a braided interior (53) between the outer and inner surfaces (45, 47), and (b) is shaped to define first and second longitudinally-running channels (27a, 27b) therethrough. A distal portion of the catheter (38) is shaped to define first and second lateral openings (26a, 26b). An angle between (a) a first line (76) running between the first and second lateral openings (26a, 26b), and (b) a second line (78) that is parallel to a central longitudinal axis of the catheter (38) when the catheter (38) is straight, is between 30 and 150 degrees. A flexible longitudinal member (14) passes from a proximal portion of the catheter (38) to the distal portion via the first channel (27a), out of the first channel (27a) via the first lateral opening (26a), into the second channel (27b) via the second lateral opening (26b), and from the distal portion to the proximal portion via the second channel (27b).

Systems and methods are disclosed herein that generally involve CED devices with various features for reducing or preventing backflow. In some embodiments, CED devices include a tissue-receiving space disposed proximal to a distal fluid outlet. Tissue can be compressed into or pinched/pinned by the tissue-receiving space as the device is inserted into a target region of a patient, thereby forming a seal that reduces or prevents proximal backflow of fluid ejected from the outlet beyond the tissue-receiving space. In some embodiments, CED devices include a bullet-shaped nose proximal to a distal fluid outlet. The bullet-shaped nose forms a good seal with surrounding tissue and helps reduce or prevent backflow of infused fluid.

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.

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.

Medical devices including a balloon-actuated sheath are provided. The medical devices include a tubular body, a tooltip, a balloon, and a tubular sheath translatably coupled to the balloon. Medical devices including a balloon-actuated distal cap are provided. The medical devices include a tubular body, a tooltip, a balloon, and a distal cap translatably coupled to the balloon. When air is pushed into one end of the medical device, the balloon may inflate, translating the tubular sheath or distal cap along a longitudinal axis from a retracted position to an extended position. When in the extended position, the tubular sheath at least partially surrounds the tooltip. When in the extended position, the distal cap at least partially opens fluid communication between the tooltip and the environment.

A medical device that includes a handle, a sheath extending from the handle, and a tool within the sheath and movable relative to the sheath. The handle includes an inner body and an outer body disposed over the inner body. The outer body is movable relative to the inner body. The handle includes a first actuator secured to the tool. The first actuator has an actuated state permitting movement of the tool relative to the sheath in response to moving the outer body relative to the inner body. The handle includes a second actuator secured to the sheath. The second actuator has an actuated state permitting movement of the sheath relative to the tool in response to moving the second actuator relative to the outer body. An unactuated state of the first actuator and an unactuated state of the second actuator prevents movement of the tool relative to the sheath.

The present disclosure relates to a catheter device comprising a catheter hub in which a valve member is disposed, a needle fixed in a needle hub, the needle extending through the valve member in the catheter hub in a ready position, and a tubular receptacle in which the needle hub is displaceably guided and biased by a spring in a proximal direction relative to the receptacle, wherein the needle hub is releasably held in the ready position in the receptacle against the force of the spring by frictional force between needle circumference and catheter or catheter hub, which frictional force is reduced on retraction of the needle through the catheter hub such that the force of the spring prevails.

Methods for treating a patient using therapeutic renal neuromodulation and associated devices, systems, and methods are disclosed herein. One aspect of the present technology is directed to methods including selectively neuromodulating afferent or efferent renal nerves. One or more measurable physiological parameters corresponding to systemic sympathetic overactivity or hyperactivity in the patient can thereby be reduced. Selectively neuromodulating afferent renal nerves can include inhibiting sympathetic neural activity in nerves proximate a renal pelvis. This can include, for example, neuromodulating via fluid within the renal pelvis. Selectively neuromodulating efferent renal nerves can include inhibiting sympathetic neural activity in nerves proximate a portion of a renal artery or a renal branch artery proximate a renal parenchyma. This can include, for example, neuromodulating via a therapeutic element within the portion of the renal artery or the renal branch artery.

A system for delivering a medical instrument into a bodily cavity is provided, including an outer shaft having an aperture in a side wall thereof, wherein the aperture is provided at a distal portion of the outer shaft, an inner shaft positioned inside the outer shaft and having an inflatable balloon disposed at a distal portion thereof, and a needle member movably disposed in the outer shaft, wherein the needle member extends outwardly from the outer shaft through the aperture when the balloon is inflated.