Abstract: Devices and methods of use for introduction and implantation of an electrode as part of a minimally invasive technique. A system includes an introducer tool including a dilator portion, a carrier portion and a release mechanism, the dilator portion selectively engageable with the carrier portion. The system further includes a lead including a lead body and an electrode structure, the electrode structure including an active side with an electrode disposed thereon, and an inactive side with an element disposed thereon. The introducer tool is configured to be temporarily inserted into a patient over a guidewire, and a portion of the release mechanism is selectively engageable with the element of the electrode structure to retain the electrode structure to the introducer tool.

Abstract: Systems and methods for creating autologous monocuspid and bicuspid valves can include a catheter having a single expandable element or a double expandable element. Once the leaflets of the valve are created, various techniques can be used to fix the leaflets to the vessel wall or to each other, including clips, tissue anchors, adhesives, and heat.

Abstract: A device for drawing spinal fluid from a body part or injecting medication into the body part is disclosed. The device may include one or more measurement features (markings) that indicate the subcutaneous depth of the device as well as confirm placement and orientation of the spinal fluid withdrawing or medication injecting end of the device in the body part. The device may include a trocar and a cannula having a patient end, a non-patient end, an outer surface, and a central passage adapted to receive said trocar. One or more windows may be provided in or on the cannula, said windows extending from the outer surface of the cannula to the central passage. The windows may be spaced from the patient end of the cannula and from each other along a specific longitudinal axis of the cannula by a predetermined distance, such as 10 millimeters.

Abstract: A cannula device for draining sub-retinal fluid externally to the eye includes a shaft, an outer sleeve, and an inner sleeve. The outer sleeve and the inner sleeve have a curve therein to access the back of the eye externally. The outer sleeve is extendable relative to the inner sleeve and the shaft, and the outer sleeve includes a penetrative tip to penetrate the sclera and provide access to the sub-retinal fluid to the inner sleeve.

Abstract: A dilator assembly comprising an elongated body having a proximal end and a distal end, a first lumen extending along the body, a second lumen extending along the body so that it is a parallel to the first lumen, and a joint lumen disposed adjacent the distal end of the body, wherein both the first lumen and second lumen are in fluid communication with the joint lumen. A guidewire has a first end and a second end, and the first end of the guidewire is slidably received in the first lumen and the second end of the guidewire is slidably received in the second lumen.

Abstract: A guidewire for use with an implant delivery system in delivering a sheet-like implant is disclosed. The guidewire can include a distal tissue fixation member for releasable connection to a first location proximate a treatment site. An implant delivery system can include a distal guidewire port for receiving the proximal end of the guidewire. The implant delivery system is tracked over the guidewire to a selected position defined by the guidewire attachment. The tissue fixation member includes means for temporarily or reversibly fixing the distal end of the guidewire to tissue, such as bone. The means for affixing can include a K-wire, a screw, a pin or other fixation member.

Abstract: A nephroureteral catheter is provided that comprises a detachable portion such that when the detachable portion is removed, the catheter converts into an internal stent. The catheter includes a tube with two retention features, a detachable portion, and an inner tube. The inner tube is removably insertable into both the tube and the detachable portion, and a wire extends through at least a portion of a lumen of the inner tube and through the tube, to keep the pieces attached. The wire may be removed to remove the inner tube and then the detachable portion from the tube. When the detachable portion is attached to the tube, the catheter is a nephroureteral catheter. When the detachable portion is removed from the tube, the catheter becomes a stent.

Abstract: Disclosed are sheaths that comprise a first sheath member having a first passageway, a first length, and a first proximal end defined by a first valve apparatus configured to seal the first passageway, the first passageway having a first passageway diameter at a location in the first passageway; and a second sheath member coupled to the first sheath member, the second sheath member having a second passageway and a second length, the second passageway having a second passageway diameter at a location in the second passageway; where the first passageway and the second passageway are separate from each other and not co-axial, the first length is different from the second length, and the first and second sheath members are positioned beside each other for a portion of their first and second lengths.

Abstract: Methods and apparatuses for space-optimized visualization catheters are provided. Some embodiments utilize complimentary metal-oxide-semi-conductor (“CMOS”) technology integrated into a CMOS camera train holder system that may be a stand-alone component for use with a visualization catheter, such as a baby endoscope, or may be fabricated/extruded as a part of the catheter itself. Some embodiments of apparatuses, methods, and equivalents thereto provide better direct visual feedback to the medical personnel performing the procedure while providing a similarly-sized outer diameter visualization catheter device having an increased space therein for additional lumens and equipment or by reducing the overall outer diameter of the visualization catheter.

Abstract: Systems are disclosed for facilitating intranasal treatment of a patient's sphenopalatine/pterygopalatine recess. Likewise the instant system is effective for addressing acute pain conditions, and is refined enough to be performed by physician's assistants, nurses, and other well-trained practitioners. Apparatus involved includes a sheath hub, a catheter hub, an arresting element, and an engagement element in embodiments. Engagement between the arresting element and the engagement element prevents rotation of the sheath hub with respect to the catheter hub.

Abstract: The invention primarily is directed to a medical tubing adapted for insertion into a body tissue or cavity and method of manufacturing different variations of the tubing along a length of the tubing. The tubing comprises a plurality of individual, discrete, generally ring-shaped elements arranged in series and fused or bonded together forming a continuous tubular structure. The ring-shaped elements may include a combination of flexible and rigid ring-shaped elements assembled along different portions or sections of the tubular structure. In another aspect of the invention, the medical tubing may further comprise a secondary lumen and a pull wire to control the tubular structure. In another aspect of the invention, the ring-shaped elements may vary in diameter and/or composition in different portions or sections of the tubular structure.

Abstract: The invention relates to a biopsy device comprising a needle extending longitudinally from a proximal end to a distal end and including a channel extending there through. At least one section (6) of the needle (3) is provided with a curved shape so that tissues that normally would be out of reach of conventional needles can be targeted.

Abstract: A multi-lumen catheter including an elliptical cross-sectional profile configuration that enhances fluid flow rate while minimizing the average diameter of the catheter body is disclosed. In one embodiment the catheter includes an elongate catheter tube defining a plurality of lumens. At least a portion of the longitudinal length of the catheter tube may define an elliptical cross section, in turn defined by a major axis and a minor axis. In one embodiment, a ratio of the major axis to the minor axis of the elliptical cross section is between about 1.3 and about 1.4. The catheter body can define two, three, or more lumens. In one embodiment, a dual-lumen catheter tube includes an aspect ratio of about 1.1:1, and each lumen thereof includes an inner surface defined by a plurality of radii and an hourglass-shaped septum.

Abstract: Several needle assemblies and intracellular delivery devices that are used for the delivery of prophylactic and/or therapeutic material (i.e., delivered agents) into a tissue of a subject are disclosed. Preferably, the needle assemblies and/or the intracellular delivery devices comprise needles and/or needle electrodes, which are disposed in an array (e.g., a Y-type array having three outer needles and a center needle), wherein each needle in the array has a closed end and a plurality of apertures along each needle barrel, and the apertures on the needle barrels of the outer needles of the array are positioned to deliver the delivered agent toward the apertures of the center needle and/or an adjacent needle, but not outside of the active zone defined by the area within the needle array and the apertures on the needle barrel of the center needle are positioned to deliver the delivered agent toward the outer needles.

Abstract: An inserter assembly for a peripheral catheter assembly configured with an adhesive plaster member, wherein the catheter tube extends through the plaster member. The inserter assembly includes a first inserter part having first and second legs, a bridge member connecting the first and second legs at a distance from each other, with the bridge member adapted for detachably engaging or holding at least a part of the needle module extending coaxially between the first and second legs. The inserter assembly includes a second inserter part for covering the needle. The plaster member impairs visual sight and the line of vision to the needle tip during puncture may be impaired. To prevent this the first inserter part serves for holding a back-folded part of the plaster member.

Abstract: A cannula assembly includes a cannula and an obturator. The cannula includes an elongated shaft dimensioned to access tissue. The elongated shaft has a lumen extending therethrough. The elongated shaft includes a first shaft segment having a first pre-determined configuration and a second shaft segment having a second pre-determined configuration different from the first pre-determined configuration. The obturator includes an elongated body adapted for insertion through the lumen of the elongated shaft. The elongated body includes a first body segment having a configuration in general accordance with the first pre-determined configuration of the first shaft segment and a second body segment selectively adaptable to conform to the second pre-determined configuration of the second shaft segment upon insertion through the lumen of the elongated shaft.

Abstract: An apparatus having a distal end that may be selectively bent in situ. The apparatus has a curved configuration and a substantially straightened configuration. First and second tubular components of the apparatus each include a distal portion that is at an acute angle with respect to a longitudinal axis of the apparatus. The second tubular component is rotatably disposed within the first tubular component. In the curved configuration, the distal portions of the first and second tubular components are positioned to extend at substantially the same acute angle with respect to the longitudinal axis of the apparatus. In the substantially straightened configuration, the distal portions of the first and second tubular components are positioned such that the curvatures thereof counterbalance each other. The first and second tubular components may be used in an occlusion bypassing apparatus for re-entering the true lumen of a vessel after subintimally bypassing an occlusion.

Abstract: An improved catheterization device of the type in which a flexible catheter overlays a rigid or semi-rigid stylet, the improvement residing in the preformed arcuate curvature of the stylet, the curvature of which can be in the form of a circular arc, an elliptical arc, or an irregular curvature, for facilitating insertion of the catheter into the blood vessel of a subject with reduced risk of vascular damage or where the direct path to the blood vessel is obstructed, and methods for its use.

Abstract: In a device (1) for monitoring and/or manipulating objects that are arranged in a cavity that can be accessed through a narrow opening, a tubular or hose-shaped insertion part (2) is provided, on which a flexible section (4) is formed, which can be controlled by a Bowden cable (5), the Bowden cable (5) acting on an actuating element (10) which is rotatably supported in a joint (11) which includes a joint socket (13) and a corresponding joint ball (12) that engages with the joint socket (13).

Abstract: Disclosed herein is a nerve block system comprising a nerve block needle and a curved introducer. Also disclosed are components of and methods of use of the nerve block system. The curved introducer of the nerve block system provides navigability and maintains column stiffness.

Abstract: The device infuses a compound subcutaneously or intradermally over an extended period of time. The delivery is from a conventional prefilled syringe with a staked cannula with the device adhered to the injection site and the syringe positioned substantially parallel to the injection site. The cannula is formed by a mechanism integral to the device to provide the cannula distal section substantially perpendicular to the syringe axis. The compound delivery is based on springs or other mechanisms. The approach offers a low cost mechanical system for the infusion of high volume, viscous compounds. The activation of the patch infuser required a few simple steps by the user. A single lever is used to trigger all device functions.

Abstract: A device for inserting a non-balloon gastrostomic device through an opening in the wall of the abdomen and stomach or other viscera of a patient is provided. The insertion device comprises a body, a stylus, and a trigger device being adapted to selectively maintain a selected position of the stylus relative to the body without the use of an external force. A method of inserting the gastrostomic device utilizing the insertion tool is also provided. In addition or alternatively, a gastrostomic device is provided including a hollow tube member and an enlarged resiliently deformable tip at one end of the tube member. The deformable tip is deformable between a first configuration and a second configuration, each configuration having a cross-sectional area. In addition or alternatively, a method is provided for forming the gastrostomic device using a disposable core.

Abstract: An insertion tool for inserting a catheter into a patient's body is disclosed. The insertion tool unifies needle insertion, guidewire advancement, and catheter insertion in a single device. In one embodiment, the insertion tool comprises a housing in which at least a portion of the catheter is initially disposed, a hollow needle distally extending from the housing with at least a portion of the catheter pre-disposed over the needle, and a guidewire pre-disposed within the needle. A guidewire advancement assembly is also included for selectively advancing the guidewire distally past a distal end of the needle in preparation for distal advancement of the catheter. In one embodiment a catheter advancement assembly is also included for selectively advancing the catheter into the patient. Each advancement assembly can include a slide or other actuator that enables a user to selectively advance the desired component. Guidewire and catheter advancement assemblies are also disclosed.

Abstract: A transseptal guidewire and methods for perforating the intra-atrial septum of the heart are disclosed. The transseptal guidewire has an elongated body, an end section biased in a curved configuration to define a proximal curve, and a distal section biased in a curved configuration to define a distal curve, the distal curve being oriented in a direction generally opposite that of the proximal curve.

Abstract: An apparatus includes a catheter for an intrathecal drug delivery system and a stylet having a curved forward end. Preferably, the curved forward end has a shape in the form of a “J” or a “C.” Also preferably, the catheter has a distal end that conforms to the curved forward end of the stylet. Thus, the present invention provides a catheter having a blunt forward end that minimizes the risk of penetrating the substance of the spinal cord. Additionally, the curved forward end of the stylet can be formed of a springy material so that it straightens out during the processes of insertion through a guide needle and retraction from the needle.

Abstract: An applicator insertable into a living body includes a nozzle having an elongated nozzle main body and a nozzle head on a front end side of the nozzle main body and through which a liquid together with a gas is expelled, with the nozzle main body including a flexible curved section. The applicator also includes an outer tube in which is positioned a portion of the nozzle main body so as to be movable along a longitudinal direction. The angle or degree of curvature of the curved section is changed by inserting the curved section into the outer tube to thereby adjust a direction of the nozzle head relative to a axis of the nozzle main body. In addition, a longitudinally extending gap exists between the outer tube and the nozzle. The gap functions as a discharge path for discharging gas within the body cavity.

Abstract: A regional anesthesia catheter used with a guide such as for example a needle cannula has a distal portion integrally connected to a main portion of the catheter by a junction portion that has a cross-sectional profile different from the distal and main portions, so as to predispose the distal portion of the catheter to move in a given direction when the distal portion is not guided by or constrained by the needle cannula. The cross-sectional profile of the junction portion may be configured in a particular shape, or be constructed to have a flexibility that predisposes the distal portion to bend, curve or move toward a given direction.

Abstract: A system includes a steerable device, such as a sheath or shaft, having proximal and distal ends. The steerable device includes an elongated body having a proximal section, a steering section, and a distal tip. Control wires are routed through the body and connected at or near the distal end of the steerable device. The system further includes a control unit to which the proximal end of the steerable device is functionally connected. In one embodiment, the control unit includes an actuator connected to one control wire and a biasing force generating device connected to a second control wire. The steering section is controllably manipulated by the control unit to facilitate steering of the distal tip of the steerable device as the steerable device is advanced through tortuous passageways of a patient's body.

Abstract: A Surgical device for invasive surgery, having a cannula with a wall for surrounding at least one lumen extending from an access end to a tissue tip. One or more instruments are slidably receivable and guidable in the lumen of the cannula, where in the surgical device is configured to be used with a medical imaging system for image guidance of the device. The cannula wall is configured to allow partial transparency with respect to a scanning signal of the medical imaging system such that at least portions of the instrument received in the cannula are visible.

Abstract: An intravascular needle and catheter arrangement that ensures flashback is indicated after the catheter is safely inserted through the needle puncture in the vascular wall and emplaced into the vessel. This placement location, at which flashback first occurs is sufficient to begin threading the catheter without risk of over-insertion or under-insertion. The catheter overlies a needle having a distal tip that defines a point. The needle tip includes an enclosed distal-most end and a port located along at least one of the proximal portion of the point and an adjacent cylindrical sidewall of the needle. The distal end of the catheter exposes the port for entry of blood from a vessel thereinto only after the distal end of the catheter has entered sufficiently into the interior of the vessel. An opposing second side of the tip defines a curved surface that prevents puncturing of the back vessel wall.

Abstract: Methods and devices are provided for providing direction to surgical tools. In one embodiment, a surgical device can include a cannulated elongate shaft with a cannulated curved distal tip. The device can be configured to be introduced into a body of a patient, and one portion of the device can be configured to be positioned on a proximal side of a tissue wall and a distal-most portion of the device including at least a portion of the curved distal tip can be configured to be positioned on the other, distal side of the tissue wall. A surgical tool can be configured to be advanced through the device to pass the surgical tool through the tissue wall with the curved distal tip providing direction for the surgical tool.

Abstract: An intravascular needle and catheter arrangement that ensures flashback is indicated after the catheter is safely inserted through the needle puncture in the vascular wall and emplaced into the vessel. This placement location, at which flashback first occurs is sufficient to begin threading the catheter without risk of over-insertion or under-insertion. The catheter overlies a needle having a distal tip that defines a point. The needle tip includes an enclosed distal-most end and a port located along at least one of the proximal portion of the point and an adjacent cylindrical sidewall of the needle. The distal end of the catheter exposes the port for entry of blood from a vessel thereinto only after the distal end of the catheter has entered sufficiently into the interior of the vessel. An opposing second side of the tip defines a curved surface that prevents puncturing of the back vessel wall.

Abstract: Device and method are provided for diagnosing and treating diseases and injuries to the spine by injecting drugs into the diseased or injured area. The device and method of the subject invention provide improvements to patient and operator safety, along with ease-of-use and convenience improvements over conventional techniques.

Abstract: An apparatus includes a catheter for an intrathecal drug delivery system and a stylet having a curved forward end. Preferably, the curved forward end has a shape in the form of a “J” or a “C.” Also preferably, the catheter has a distal end that conforms to the curved forward end of the stylet. Thus, the present invention provides a catheter having a blunt forward end that minimizes the risk of penetrating the substance of the spinal cord. Additionally, the curved forward end of the stylet can be formed of a springy material so that it straightens out during the processes of insertion through a guide needle and retraction from the needle.

Abstract: A trocar system for providing access across a body wall includes a trocar and an anchor provided in the form of a first helix. The anchor is adapted for placement in an operative position wherein the anchor extends at least partially through the body wall. A second helix formed on the trocar is size and configured to engage the first helix of the anchor so that rotation of the trocar relative to the anchor moves the second helix along the first helix. In this manner, the trocar is drawn into the anchor as it moves into the body wall. A proximal force applied to the anchor resists tenting of the abdominal wall. The anchor also holds the layers of the body wall together thereby resisting peritoneal separation.

Abstract: A support catheter that can puncture a heart septum with a guidewire without buckling and that can access difficult to reach arteries such as carotid or renal arteries from the aorta under difficult circumstances is provided. The support catheter comprises a catheter body having a proximal end, a distal end, and an interior wall surface defining a first lumen extending from the proximal end toward the distal end. A second lumen is disposed between the interior wall surface and an outer surface of the catheter body. A plurality of stiffening members is disposed around the second lumen, the plurality of stiffening members being engageable to selectively stiffen the catheter body. In another configuration, the catheter further comprises a second plurality of stiffening members disposed between the first lumen and the second lumen.

Abstract: A trocar tube, trocar, obturator, rectoscope is suitable for transluminal endoscopic surgery via natural body cavities. A trocar tube (2) has a distal section (22) for positioning at least in the region of or outside the body cavity, and a proximal section (21) for positioning within the human or animal, wherein at least the proximal section has a substantially rigid or inflexible curvature. An obturator (3) and a rectoscope (5) may be adapted for use with such a trocar tube for this purpose.

Abstract: A catheter-insertion assembly includes a catheter with a proximal end and a distal end, a needle with a proximal end and a beveled distal end forming a sharp distal point, and an obturator with a proximal end and a distal end. The distal end of the obturator includes at least one bend. The bend allows the distal end of the obturator to protect the catheter from the sharp distal point of the needle during insertion of the needle through the catheter.

Abstract: The instant invention is directed toward transseptal puncture needles and transseptal puncture needle assemblies. More specifically, it relates to curved transseptal puncture needles and needle assemblies that facilitate insertion through curved transseptal introducers. Each curved transseptal puncture needle includes a needle tip with a tangential back bevel configuration, a reverse tangential back bevel configuration, or a conical reverse bevel configuration. The axial orientation of the needle tip relative to the needle curvature, whether on the concave side or convex side of the curved transseptal puncture needle, provides additional benefits. The leading edge of the needle tip is located at a distal end of an inner needle tube, and the leading edge of the needle tip may be positioned away from an outer surface of the inner needle tube and adjacent to an inner surface of the inner needle tube.

Abstract: A trocar needle includes an elongate body having a distal end portion and a proximal end portion, a penetrating tip formed at the distal end portion of the body, and an attachment portion formed at the proximal end portion for attaching a tether thereto. A grip region can further be provided and can be formed for example, at the proximal end portion of the body to facilitate gripping by a surgical grasping device. Additionally or alternatively, a notch or otherwise reduced cross-sectional area can be provided. Such a feature can be formed, for example, at the distal end portion of the body, arranged proximal from a distal end thereof for enhancing haptic perception by a surgeon when utilizing the needle.

Abstract: Devices and methods are disclosed for providing a sensing element to scan tissue and detect the presence of structures within the tissue to avoid the structures when performing a procedure on the tissue. A tissue penetrating member or needle is extendable from the device to create a channel or opening through the wall of an airway. The device is sufficiently flexible to navigate turns of at least 90 degrees. The distal section of the device includes puncture resistant sections, a curved needle tip, and depth limiting features that serve to create a channel in the lumen wall without causing collateral damage to the instruments, or patient.

Abstract: A transseptal guidewire and methods for perforating the intra-atrial septum of the heart are disclosed. The transseptal guidewire has an elongated body, an end section biased in a curved configuration to define a proximal curve, and a distal section biased in a curved configuration to define a distal curve, the distal curve being oriented in a direction generally opposite that of the proximal curve.

Abstract: An introducer for providing intravascular access to a patient is disclosed, and includes a dilator and sheath that are configured to prevent peelback, or “fishmouthing,” of the sheath during introducer advancement. In one embodiment, the introducer comprises a dilator including a distal tapered region, and a sheath including an inner bore that receives the dilator such that a portion of the tapered region of the dilator extends from the sheath distal end. A distal outer surface of the sheath includes a first curved portion defined by a first radius and extending proximally from the distal end of the sheath to a first end point, and a second curved portion defined by a second radius and extending proximally from the first end point to a second end point. Additionally, an interference fit is established between the dilator tapered region and the sheath distal end to further prevent sheath end deformation.

Abstract: A medical apparatus for insertion into a body cavity which comprises an elastic linear body and delivers the distal tip to the predesignated object portion in a living organ, wherein the elastic linear body comprises a plurality of curved portions between the proximal end and the distal end, and at least one pair of adjacent curved portions are present on different planes which intersect each other. The apparatus can spontaneously control the direction thereof, and the distal tip can be delivered to the predesignated object portion in a living organ accurately and easily by pushing the apparatus into a body cavity.

Abstract: An improved catheterization device of the type in which a flexible catheter overlays a rigid or semi-rigid stylet, the improvement residing in the preformed arcuate curvature of the stylet, the curvature of which can be in the form of a circular arc, an elliptical arc, or an irregular curvature, for facilitating insertion of the catheter into the blood vessel of a subject with reduced risk of vascular damage or where the direct path to the blood vessel is obstructed, and methods for its use.

Abstract: The invention encompasses various introducer devices, typically used in conjunction with another, elongated medical device. The devices of the invention direct a medical device around or toward a desired anatomical feature through a tube having straight and curved regions. In preferred embodiments, the introducers of the invention are used with a device having a preformed shape, such as the sizing introducers used in atrial fibrillation treatments.

Abstract: Probe for providing a fluid connection with the small intestine comprising a tube (10) to be inserted in the small intestine via the stomach, having proximal and distal open ends (10A, 10B) and inherent tendency of coiling over a predetermined length at the distal end, and a guide (14) displaceable in the tube from the proximal end for straightening said length in order that it shall be straightened during the actual insertion into the stomach. According to the invention the tube has at least in said predetermined portion a hairy, frosted, rough, ribbed or finned outside surface (16).

Abstract: A vascular introducer assembly is disclosed that includes a dilator, a sheath having an axial lumen for accommodating the dilator, a locking collar for securing the dilator and the sheath to one another and an adjustable hemostatic seal for preventing fluid egress from the axial lumen and restricting insertion of instruments through the axial lumen.

Abstract: An orthogonal arterial catheter preferably includes a hub and a cannula. The hub preferably protects the cannula from potential kinking and shearing forces because the cannula upon exiting a patient's body enters the hub. The hub preferably provides a passageway through which the hose travels to a connector piece. The connector piece preferably attaches the device to a fluid line such as an arterial line transducer. In addition, the hub preferably includes a port that provides a channel through which a guide wire or a needle may gain access to the cannula. The hub also may include appendages extending from it to suture to the patient.

Abstract: A medical device is provided having a needle or a catheter, insertable into a living body, which defines a plurality of holes in fluid communication with a central lumen. The holes may be of various patterns located and angled to create a desired injectate cloud pattern when an injectate is forced through the central lumen and through the plurality of holes. One embodiment provides various designs including a moveable sheath or stylet used to selectively occlude one or more of the holes while in use, thereby providing an operating physician a way to manipulate the cloud pattern anytime during the introduction of the injectate. A reducer may be used in conjunction with these needles which provides an increased degree of control when injecting very small quantities of fluid.