Systems and methods for a cerebrospinal fluid flow detector

Embodiments for a cerebrospinal fluid flow detector for detecting the flow of cerebrospinal fluid are disclosed. In some embodiments, the cerebrospinal fluid flow detector includes a casing with a rotatable wheel having a plurality of radially extending arms disposed therein. The rotatable wheel is in communication with a channel having a distal end in communication with an inlet port and a proximal end in communication with an outlet port such that the flow of cerebrospinal fluid through the channel causes the rotatable wheel to rotate. In some embodiments, each radially extending arm includes at least one radiopaque marker in which movement of the rotatable wheel caused by fluid flow through the channel allows an X-ray imaging apparatus to detect the difference in position of a respective radiopaque marker at multiple times caused by rotation of the rotatable wheel.

FIELD

The present disclosure generally relates to a fluid flow detector, and in particular to systems and methods for a fluid flow detector having a rotary wheel that allows detection of cerebrospinal fluid based on movement of the rotary wheel in the presence of cerebrospinal fluid flow through the fluid flow detector.

BACKGROUND

Shunts are medical devices having various tubes referred to as catheters. Shunts are minimally used to allow excess fluids that build up in one portion of the body to be drained into another portion of the body, thereby normalizing fluid flow pressure in the first portion of the body. Typically, patients are implanted with one or more catheters, separated by one or more one-way valves to allow the excess fluid to periodically drain from the over-pressurized area in the body.

In particular, ventriculoperitoneal shunts are used to treat patient with hydrocephalus. These shunts allow passage of cerebrospinal fluid from the ventricles in the brain to the peritoneal cavity. Due to the excess protein levels in the cerebrospinal fluid of these patients, the shunt valves often become occluded.

In addition, there have been numerous issues associated with shunt systems intended to drain cerebrospinal fluid from the brain to the peritoneal cavity. For various reasons, such as a build-up of protein within the interior of a shunt system, kinking of a shunt catheter, or migration of the distal catheter out of the peritoneum, a shunt system may become occluded, therefore reducing or preventing the flow of cerebrospinal fluid. Symptoms of a blocked shunt system can be serious if left unchecked, and can result in frequent visitations to the emergency room.

In some cases, the ventricles in the brain in which the cerebrospinal fluid accumulates do not change size in response to elevated or depressed levels of cerebrospinal fluid. Therefore, traditional imaging techniques, such as computed tomography scanning of the brain, are unable to determine whether or not the cerebrospinal fluid flow through a shunt is occurring as intended. As a result, physicians often must resort to invasive techniques, such as a shunt tap, to detect the flow of cerebrospinal fluid. During a shunt tap, a needle is placed through the scalp into the shunt reservoir of the shunt system. The cerebrospinal fluid is then withdrawn, and the fluid pressure measured to determine if the cerebrospinal fluid has been flowing through the shunt system.

This procedure can result in a number of problems. First, the procedure can be uncomfortable for the patient and can result in an infection. Second, the procedure requires interpretation by an experienced physician, resulting in the need for the procedure to be performed at a facility with neurosurgical services.

DETAILED DESCRIPTION

Various embodiments of a fluid flow detector capable of detecting the presence of cerebrospinal fluid are disclosed herein. In some embodiments, the fluid flow detector is in selective fluid flow communication with a shunt reservoir for receiving cerebrospinal fluid that passes through a shunt valve. In some embodiments, the fluid flow detector includes a casing having a wheel housing disposed therein with a rotatable wheel inside the wheel housing, the rotatable wheel housing defining a plurality of radially extending arms. The casing further includes a fluid pathway in fluid flow communication between an inlet port and an outlet port configured to permit fluid flow of cerebrospinal fluid from the shunt reservoir through the fluid flow detector. In some embodiments, at least one of the radially extending arms of the rotatable wheel is partially disposed within the fluid pathway of the channel such that any flow of cerebrospinal fluid through the channel of the fluid flow detector causes movement of the rotatable wheel due to the force of the fluid flow against one or more of the radially extending arms. In some embodiments, each radially extending arm may include at least one radiopaque marker in which movement of the rotatable wheel caused by the flow of cerebrospinal fluid through the channel allows an X-ray imaging apparatus to observe the difference in position of each respective radiopaque marker, if any, at multiple time frames. In one method of detecting the presence of cerebrospinal fluid, an X-ray imaging apparatus periodically takes a plurality of images of the radiopaque markers located on one or more of the radially extending arms such that the position of the radiopaque markers observed in each respective image may be determined to indicate whether movement of the radially extending arms has occurred, and therefore indicate the presence of cerebrospinal fluid within the fluid flow detector. Referring to the drawings, embodiments of a fluid flow detector for detecting the presence of cerebrospinal fluid are illustrated and generally indicated as100inFIGS. 1-13.

Referring toFIGS. 1-8, in some embodiments the fluid flow detector100may include a casing102collectively defined by a top portion122, a bottom portion123, a first side portion126, an opposite second side portion128, a first end portion130, and an opposite second end portion132. In some embodiments, an inlet port116extends outwardly from the first end portion130and an outlet port118extends outwardly from the second end portion132of casing102. In some embodiments, the inlet port116may include a male port configured to engage in fluid tight engagement one end of a catheter103C (FIG. 11). As shown, the casing102further defines an interior chamber104in which a wheel housing108is disposed therein. In some embodiments, the wheel housing108defines a circular-shaped housing configured to receive a rotatable wheel110therein that rotates about an axis300as illustrated inFIG. 2.

As shown inFIGS. 2, 9 and 10, the rotatable wheel110defines a plurality of radially extending arms112in which each arm112extends radially from an axle114at the center of the rotatable wheel110which rotates about axis300. In some embodiments, the rotatable wheel110defines eight radially extending arms112A-112H, although in other embodiments any plurality of radially extending arms112sufficient to rotate the rotatable wheel110in the presence of cerebrospinal fluid within a channel106of the fluid flow detector100is contemplated. In some embodiments each of the radially-extending arms112defines an elongated member having a distal portion146that forms the free end of the radially extending arm112and a proximal portion148that extends radially from the axle114, such as illustrated by radially-extending arm112D illustrated inFIG. 9.

In some embodiments, some or all of each of the radially extending arms112includes at least one radiopaque marker136for providing a visual indicator to an X-ray apparatus which may indicate the present position of the radiopaque marker136when an X-ray image is taken. In some embodiments, first and second radiopaque markers136A and136B may be aligned in series along the longitudinal axis of each respective radially extending arm112as shown inFIGS. 2, 9 and 10. In other embodiments, each radiopaque marker136may define a single radiopaque marker or a plurality of radiopaque markers136. In some embodiments, each of the radiopaque markers136may define a circular-shaped configuration, a square-shaped configuration, a rectangular-shaped configuration, an oval-shaped configuration, an asymmetrical-shaped configuration, a symmetrical-shaped configuration, and/or an angular-shaped configuration. In some embodiments, one or more radiopaque markers136may extend along the longitudinal axis of each respective radially extending arm112. In some embodiments, the entire rotatable wheel110may be made from a radiopaque material or only the radially extending arms112may be made from a radiopaque material. In some embodiments, each of the radiopaque markers136may have the same configuration or different configurations. In some embodiments, the radiopaque markers136may each have a respective numerical designation.

Referring toFIGS. 1, 9 and 10, in some embodiments an elongated channel106defines a lumen that establishes a fluid pathway between the inlet port116and the outlet port118of the casing102. In some embodiments, the channel106defines a distal portion138in communication with the outlet port118, a central portion139in communication with the wheel housing108, and a proximal portion140in communication with the inlet port116. As shown, the distal portion138of the channel106communicates with the inlet port116through a proximal opening144and the proximal portion140communicates with the outlet port118through a distal opening142. As further shown, a central portion139of the channel106communicates with a lateral opening120of the wheel housing108such that at least one of the radially extending arms112of the rotatable wheel110extends into the channel106. This structural arrangement between the rotatable wheel110and the channel106allows the fluid flow detector100to detect the presence of cerebrospinal fluid any time the rotatable wheel110is made to rotate due to the force applied by the flow of cerebrospinal fluid against one or more of the radially extending arms112.

In some embodiments, one or more radiopaque reference markers134along the casing102provide a fixed visual reference for determining whether any movement of a radiopaque marker136has occurred over time when fluid flow through the fluid flow detector100occurs. The radiopaque reference markers134may be made from a radiopaque material positioned at particular locations along the casing102as shown inFIG. 10. In some embodiments, the fluid flow detector100includes three sets of radiopaque reference markers134A,134B and134C. As shown, radiopaque reference marker134A may be a single radiopaque marker134positioned proximate the central portion139of channel106, radiopaque reference markers134B may be a pair of radiopaque markers positioned between the outlet port118and the wheel housing108, and radiopaque reference markers134C may be three aligned radiopaque markers positioned between the inlet port116and the wheel housing108. In other embodiments, any number of radiopaque reference markers134may be positioned along the casing102to provide a fixed visual reference for determining whether the radiopaque marker(s)136on the rotatable wheel110have moved when cerebrospinal fluid flows through the channel106. In some embodiments, only one radiopaque reference marker134may be used as a visual reference.

As noted above, the flow of cerebrospinal fluid through the channel106applies a force to one or more of the radially extending arms112of the rotatable wheel110that extend into the channel106through the lateral opening120of the wheel housing108as illustrated inFIG. 10. As such, rotary movement B of the radially extending arms112changes the position of the radiopaque markers136relative to the fixed radiopaque reference markers134, thereby providing a visual indication of flow A of cerebrospinal fluid through the fluid flow detector100.

Referring toFIGS. 11 and 12, in some embodiments the fluid flow detector100may communicate with a catheter103B which is coupled between the inlet port116of the casing102and a shunt reservoir and valve component101. The shunt reservoir and valve component101stores excess cerebrospinal fluid that flows through a ventricular catheter103A disposed within the ventricle of an individual. As further shown, one end of a catheter103C is coupled to the outlet port118of the fluid flow detector100and the opposite end of the catheter103C terminates within a peritoneal cavity of the individual. In this arrangement, fluid flow A of cerebrospinal fluid from the ventricle of the individual is stored in the shunt reservoir and valve component101which is operable to periodically pass the cerebrospinal fluid through the fluid flow detector100. Once fluid flow A of cerebrospinal fluid exits the fluid flow detector100, the cerebrospinal fluid is allowed to flow into the peritoneal cavity of the individual. As further shown, an X-ray apparatus190may be implemented to capture X-ray images associated with the radiopaque markers136of the fluid flow detector100. Specifically, as shown inFIG. 11, the X-ray apparatus190may be oriented over the fluid flow detector100to capture X-ray images of the fluid flow detector100, which may reveal a movement of the radiopaque markers136, as described herein.

One method of detecting cerebrospinal fluid is illustrated in the flow chart shown inFIG. 13. Block200ofFIG. 13involves coupling a fluid flow detector to a flow source such as a shunt reservoir. The fluid flow detector includes a rotatable wheel with a plurality of radially extending arms with each of the plurality of radially extending arms having one or more radiopaque markers. At block202, a first X-ray image is captured showing a first position of one or more radiopaque markers at a first time sequence. At block204, a second X-ray image is captured showing a second position of the one or more radiopaque markers at a second time sequence. At block206comparing the first position of the one or more radiopaque markers with the second position of the one or more radiopaque markers to determine whether a change of position of the one or more radiopaque markers has occurred over time which provides a visual indication of cerebrospinal fluid flow through the fluid flow detector.

In some embodiments, the method ofFIG. 13may further include determining a time value associated with a change in time between the first time sequence and the second time sequence; and determining a rate of the fluid flow through the fluid flow detector using the time value associated with the change in time and a position value associated with any difference in position of the radiopaque marker between the first time sequence and the second time sequence.