Patent Description:
Medical treatment often involves the use of IV therapy, where fluids such as saline, blood, and/or medication are administered directly into the vein of a patient. Document <CIT> discloses a method of loading and discharging a drip chamber. A flexible tube is mounted on top of the drip chamber. The top of the tube is connected to the spike via a one-way ball-type valve. The bottom of the tube is connected to the drip chamber via a duck-bill-type valve inside of the drip chamber. The duck-bill is held closed against head pressure by a metal spring clip acting on the lip. The duck-bill will open when the tube is squeezed and fluid will be injected into the drip chamber. The drip chamber is charged bubble-free by the use of an output tube open to the chamber and joined to the flexible tubing carrying the hypodermic needle.

IV systems used for IV therapy commonly employ a drip chamber, which allows a clinician (e.g., a nurse) to determine rate at which the IV fluid is administered by manually counting the number of drops over a given period of time. Drip chambers are sometimes classified as macro-drop or micro-drop based on their drop factor, defined as the number of drops per milliliter (mL) of IV fluid provided. For example, macro-drop drip chambers commonly employ a drip factor of about <NUM> gtts/mL (or drops/mL), while micro-drop drip chambers commonly employ a drip factor of about <NUM> gtts/mL.

In one or more implementations, not all of the depicted components in each figure may be required, and one or more implementations may include additional components not shown in a figure. Variations in the arrangement and type of the components may be made without departing from the scope of the subject disclosure. Additional components, different components, or fewer components may be utilized within the scope of the subject disclosure.

The detailed description set forth below is intended as a description of various implementations and is not intended to represent the only implementations in which the subject technology may be practiced. As those skilled in the art would realize, the described implementations may be modified in various different ways, all without departing from the scope of the present disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive.

A drip chamber in an intravenous therapy system may be constrained in the precision at which flow rate can be measured based on its drop factor, in turn constraining the range of flow rates that can be accurately delivered to the patient. For example, neonatal, diabetic, or other fluid restricted patients may require infusion or IV fluid delivery at a slow rate on the order of one mL or a few mL per hour. Even for a micro-drop drip chamber having a drip factor of <NUM> drops/mL, this can lead to a drop rate as slow as one drop per minute, which may not permit accurate or practical measurement by a clinician using a stopwatch and counting the number of drops. Further, with such low flow rates, even small errors can significantly affect treatment. Automated pumps can provide more precise control over the flow rate, but these add cost and complexity, and pumps may be impractical for certain markets and environments.

In accordance with the invention, drip chambers, and IV therapy systems and methods employing drip chambers, allow for smaller drop sizes to permit more accurate metering of low flow rates and/or facilitate more precise flow rate measurements compared to existing technologies. In accordance with the invention, drip chamber employs a solid pin, wire, or other drop former structure that permits IV fluid to wick down an outside surface of the drop former. The drop former can terminate in a sharp solid point to reduce surface area and induce drops to fall from the drop former at a smaller volume. An acoustic emitter is employed to stimulate a formation or release of drops from the drop former. Additionally or alternatively, a gas inlet port can be included to permit or other gas to be injected in the drip chamber to break up flow and induce drop release from the drop former. Additionally or alternatively, a piezoelectric sensor can be utilized to detect the impact of falling drops and permit small drops to fall at a faster rate than may be reliably counted with a human eye.

However, those skilled in the art will appreciate various alterations and other embodiments that can employ principles of this disclosure without departing from the scope of the concepts disclosed herein. Thus, it is understood that the detailed figures and discussion provided herein is for explanatory purposes only and should not be construed as limiting.

<FIG> is a schematic diagram of an example IV therapy system <NUM> that can be used to administer fluids to a patient. The IV therapy system <NUM> includes an IV bag <NUM> containing a reservoir of fluid <NUM> to be administered to a patient <NUM>, a catheter <NUM> inserted into the patient's vein for delivering the IV fluid, and an IV line <NUM> that provides tubing to convey the fluid from the IV bag <NUM> to the catheter <NUM>. A drip chamber <NUM> is coupled between the IV bag <NUM> and the catheter <NUM> to form drops of the fluid <NUM> at a known drop factor. The drop formation in the drip chamber <NUM> can provide a metric to determine a flow rate, for example, by allowing counting or measurement of the number of drops over a period of time. A control mechanism <NUM>, such as a roller clamp coupled to the IV line, can be used to adjust the flow rate as desired based on the flow rate determined from the drip chamber.

<FIG> is an illustration of an example IV administration set <NUM>. The IV set <NUM> is a particular example of a device that includes a drip chamber and other operative components of a fluid administration system. The IV set <NUM> includes a modular design to allow for insertion in and removal from an IV system as desired. The IV set <NUM> can, for example, be employed in the IV therapy system <NUM> or any other appropriate fluid administration system.

As shown in <FIG>, the IV set <NUM> includes a drip chamber <NUM>, an IV line <NUM>, a luer lock fitting <NUM>, and a roller clamp <NUM>. The drip chamber <NUM> has a container for holding an IV fluid. A proximal end of the drip chamber <NUM> can include an inlet port to receive fluid from the fluid reservoir, while a distal end of the drip chamber <NUM> can include an outlet port to provide the fluid downstream to the patient through an IV line <NUM>. The drip chamber <NUM> can be configured to receive the fluid using a gravity feed from the fluid reservoir, where the proximal end of drip chamber <NUM> corresponds to an upper end (or top end) and the distal end corresponds to a lower end (or bottom end) in a gravitational frame of reference. A drop former <NUM> is suspended from the upper end of the drip chamber <NUM> and can extend downward from the upper end partially into an interior cavity of the container. The drop former <NUM> can, for example, be made from plastic, metal, and/or any other suitable material, and the drop former <NUM> can, for example, include a tube, pin, wire, cylinder, flared tip, or other structure that forms drops of IV fluid that can fall into the container below. During operation, the drip chamber <NUM> may initially be primed with the IV fluid (e.g., to a level of approximately half full) so that air or other gases are allowed to disperse and do not enter the IV line <NUM> below upon impact of the drops of the IV fluid, which is a liquid, from the drop former <NUM>.

The IV set <NUM> includes spike <NUM> at a proximal end which can contain the inlet port therein and couple to an IV bag (e.g., IV bag <NUM> of <FIG>). The IV bag can contain the fluid reservoir, which can provide a source of fluid to be delivered to the patient. The IV set <NUM> shown in <FIG> is implemented with a spike-type drip chamber, with the spike <NUM> included in a cap at the upper end of the drip chamber <NUM> so that the drip chamber itself can attach directly to a bottom of the IV bag through the spike <NUM>. A protective cover <NUM>, which is shown removed from the spike <NUM> in <FIG>, can cover the spike <NUM> during initial delivery or transport before use. At the opposing, distal end of the IV set <NUM> is a male luer fitting <NUM>, which is disposed at the end of a segment of the IV line <NUM>. The male luer fitting <NUM> provides a connector to couple to downstream or distal components, such as a catheter or an additional IV line segment through which the fluid is delivered to the patient.

A roller clamp <NUM> is included in the IV set <NUM> along the IV line. The roller clamp <NUM> provides a control mechanism allowing for manual adjustment of the flow rate by a user (e.g., a clinician). The drip chamber <NUM> can include a sufficiently transparent exterior surface to allow the user to see the drops falling from the drop former <NUM>, so that the drip rate of the drops can provide a visual check for the user to determine flow rate. For example, the user may use a stopwatch, count the number of drops over a set period of time, and determine the flow rate based on counted number of drops, the time period, and a known drop factor of the drip chamber <NUM>. Additionally or alternatively, the drip chamber <NUM> can include a sensor, such as a piezo electric sensor, to count or otherwise detect drops falling in the drip chamber. The user may then adjust the flow rate up or down accordingly by manipulating the roller clamp <NUM> based on the desired treatment of the patient.

<FIG> is an illustration of an example IV set <NUM>. The IV set <NUM> is another example of a device that includes a drip chamber and other operative components of a fluid administration system. The IV set <NUM> includes an inline drip chamber <NUM>, which is disposed along an IV line rather than being configured to couple directly to an IV bag like the drip chamber <NUM> of <FIG>. The IV set <NUM> can, for example, be employed in the IV therapy system <NUM> or any other appropriate fluid administration system.

The top end or cap of the inline drip chamber <NUM> can include an inlet port coupled to a proximal or upstream segment of the IV line <NUM> between the drip chamber <NUM> and the IV bag. The IV set <NUM> shown in <FIG> further includes a pair of connectors at its proximal end for coupling to a pair of respective fluid reservoirs (e.g., an IV bag for saline and a separate IV bag for blood, or any other appropriate combination of fluids to be delivered to a patient). Unlike the example of <FIG>, in which spike is included directly on the top side or cap of the drip chamber <NUM> (<FIG>), the IV set <NUM> in <FIG> includes a pair of spikes <NUM> respectively disposed at the ends of a pair of IV line segments at the proximal end of the IV set <NUM>.

A pair of roller clamps <NUM> are provided on the pair of IV line segments, respectively, and can allow for individual adjustment of the flow rate for each respective fluid reservoir. The roller clamps <NUM> are provided proximal to and upstream from the drip chamber <NUM>, between the drip chamber <NUM> and fluid reservoirs, in contrast to the IV set <NUM> of <FIG>, in which roller clamp <NUM> (<FIG>) is disposed distal to and downstream from the drip chamber <NUM> (<FIG>), between the drip chamber and the patient. The IV set <NUM> also includes various additional components to provide additional functionalities. For example, access connectors <NUM> are shown disposed along the IV line <NUM> to allow additional fluid transfer devices (e.g., needless syringes or other components) to be coupled to and removed from the IV line <NUM> for delivery to or removal of additional fluids from the patient as desired. A slider clamp <NUM> is also shown disposed along the IV line <NUM> to provide an additional control mechanism for stopping or starting the flow rate.

<FIG> is a cross section view of an example drip chamber <NUM>. The drip chamber <NUM> is a particular example of a drip chamber that employs a solid pin, wire, or other drop former structure providing an outer surface for the IV fluid to descend. The drop former structure can terminate in a small point to encourage the drop, or series of drops, to fall down the outside surface and release from the tip of the drop former at a smaller volume. In some embodiments, the drip chamber <NUM> can share features in common with any one or more of the drip chambers shown in <FIG>.

The drip chamber <NUM> includes a container <NUM>, a cap <NUM>, and an internal cavity <NUM> within the container and enclosed by the cap <NUM>. The container <NUM> can have a substantially cylindrical body, or any other appropriate structure to permit holding the IV fluid with an interior cavity of the container body. The cap <NUM> is disposed on an upper side or proximal end of the container <NUM>, and includes a spike <NUM>, which can be configured to couple to an IV bag containing a fluid (e.g., by insertion of the spike into a bottom end or port in the IV bag). An inlet port <NUM> is included in the proximal end of the container and can be configured to receive the fluid from the IV bag. As shown in <FIG>, the inlet port <NUM> extends through the spike <NUM> and through the cap <NUM>, and is coupled to a drop former <NUM> at an upper side or proximal end of the drip former. The inlet port <NUM> is disposed above the drop former to permit the IV fluid to descend to the drop former. Although shown as including a lumen extending through the cap, in various configurations the inlet port can have any suitable opening, channel, or other structure to permit receipt of IV fluid flowing into the drip chamber. Further, although the drip chamber <NUM> is shown as including a spike <NUM> that can be used for direct connection to an IV bag, the drip chamber <NUM> can additionally or alternatively be implemented as an inline drip chamber that does not employ spike <NUM>, but rather, for example, has an inlet port configured to couple to an upstream segment of an IV line.

The drop former <NUM> is suspended from the cap <NUM> and extends distally from the cap <NUM> in a downward direction partially into the interior cavity <NUM>. The drop former <NUM> is configured to form a drop of the fluid received from the inlet port <NUM>, and can be configured to release a steady rate of drops into the interior cavity <NUM> and into the container <NUM> to permit a flow rate measurement or estimation by counting of the drops. The drop former <NUM> can, for example, be implemented as a solid pin, wire, or other elongated member. The drop former <NUM> can terminate in a lower tip <NUM> (or "distal tip") at its lower or distal end, which provides a release point for a drop of the IV fluid <NUM> to fall into the container <NUM>.

An outer surface <NUM> that is between a proximal end and the distal end of the drop former <NUM> can be coupled directly or indirectly to the inlet port <NUM> to receive the IV fluid <NUM> from the inlet port <NUM>. The outer surface <NUM> can extend in a downward direction and terminate at the distal tip <NUM> to permit the IV fluid <NUM> to descend down the outer surface <NUM> towards a small release point at the distal tip <NUM>. A lateral surface on an exterior of a pin, wire, or other elongated member can provide the outer surface <NUM> for fluid to descend down. A small solid point at the lower tip <NUM> below the outer surface <NUM> can allow formation and release of small drops that may be smaller than those formed by a <NUM> drop/mL or purely tube type drip chamber having an internal resistance that constrains the size of drops. By way of example, the drop former <NUM> can be configured (e.g., based on its dimensions) to form drops on the order of <NUM> to <NUM> drops/mL, or any other desired size.

The drop former <NUM> can have a uniform diameter throughout its entire length. Alternatively, the drop former <NUM> can reduce to a smaller diameter at the distal tip, such as a pin implementation where the distal (lower) tip of the pin has a smaller diameter or size than a proximal (upper) part of the pin. The drop former <NUM> can have a solid construction throughout its length, with no lumen or interior fluid pathway provided through the entire extent of the drop former, or the drop former <NUM> can have a solid construction at only a distal section terminating in the distal tip <NUM>, for example, which provides a release point for the drops of the fluid <NUM>.

The drop former <NUM> can be coupled to the fluid source and coupled to the inlet port <NUM> through a small hole <NUM>, or pinhole, which can be included in the cap <NUM> between the upper end of the inlet port <NUM> and the lower end of the drop former <NUM>. The size of the hole can be sufficiently small so that a surface tension of the fluid prevents a gravity force from allowing a free fall of the fluid through the hole <NUM>. In this example, the drop former <NUM> includes a proximal section disposed in the hole <NUM>, which can allow the drop former <NUM> to wick fluid through the hole <NUM> by capillary action, for example, with a wire shape that wicks fluid similar to the wick of a candle. Alternatively, the drop former <NUM> may be coupled to the inlet port <NUM> through any other appropriate structure or arrangement that allows the fluid to descend down the outer surface <NUM> of the drop former <NUM>.

An outlet port <NUM> is included at a distal end of the container <NUM>. The outlet port <NUM> is configured to couple to IV line <NUM> to allow fluid to be provided downstream from the interior cavity <NUM> of the drip chamber <NUM> through the IV line <NUM> and to the patient. In <FIG>, the drip chamber <NUM> is shown after priming with IV fluid <NUM> to a level at approximately halfway up the container. All or a portion of the container can be made sufficiently transparent to allow the drops falling from the drop former <NUM> to be visible from an exterior of the drip chamber <NUM>. For example, the container <NUM> can be made of a transparent plastic, in whole or in part, to allow the formation and/or release of the drops to be visible to a user (e.g., a clinician) from an exterior of the drip chamber <NUM> to permit manual counting of the drops by the user.

<FIG> is a cross section view of an example drip chamber <NUM>. The drip chamber <NUM> is a particular example of a drip chamber that employs electronics, such as an acoustic emitter, to energize a drop former to stimulate ejection or release of small drops form the drop former. In some embodiments, the drip chamber <NUM> can share features in common with any one or more of the drip chambers shown in <FIG>.

The drip chamber <NUM> includes a drop former <NUM>, which can be suspended from a cap <NUM> and configured to release a drop of IV fluid <NUM> into an interior cavity <NUM> of a container <NUM>. The drop former <NUM> is shown in <FIG> as including a tubular structure having an inner lumen through which the fluid from the inlet port <NUM> passes through to a distal tip of the tubular structure. Additionally or alternatively, the drop former <NUM> can employ any suitable structure for forming and releasing drops, such as, for example, a pin or wire with a solid distal tip like that shown in <FIG>.

The drip chamber <NUM> includes an electronic component <NUM> housed within the cap <NUM>. The electronic component <NUM> is operatively coupled to the drop former <NUM> and configured to stimulate drop formation and/or release therefrom. The electronic component <NUM> may be operatively coupled to the drop former directly or through intervening components, such as through the cap, so long as the coupling is sufficient to permit the electronic component to interact with the drop former <NUM>. The electronic component <NUM> can, for example, include an acoustic emitter, which can be operatively coupled to the drop former <NUM> through any appropriate physical or mechanical coupling that permits sound waves or other signals emitted from the component <NUM> to reach a surface of the drop former <NUM>. Additionally or alternatively, the electronic component can include circuitry, a power source (e.g., a battery), wires, and/or other electronics to facilitate energizing the drop former <NUM>.

Acoustic energy or mechanical vibrations generated or otherwise provided by the electronic component <NUM> can be configured to overcome a resistance or surface tension of the fluid in the drop former to trigger release of a drop that might not otherwise fall relying on gravity or pressure differences alone. The electronic component <NUM> can, for example, be configured to stimulate the drop former <NUM> periodically, such as by generating a burst of acoustic energy periodically in synchronization with a predetermined drop rate, which can be fixed or user-programmable.

The electronic component <NUM> can be housed within an enclosure of the cap <NUM> that is sealed or otherwise insulated from the fluidic pathway of the fluid <NUM> (e.g., insulated from the inlet port <NUM> and the interior cavity <NUM>). This can permit the electronic component <NUM> to be insulated from sterile components and/or allow the electronic component <NUM> to be removed from the cap <NUM> and reused in other drip chambers, while a remaining structure of the drip chamber <NUM>, such as container <NUM> and/or drop former <NUM>, can be discarded after each instance of use. The electronic component <NUM> is shown in <FIG> as an annular structure at least partially surrounding the inlet fluid pathway, but the electronic component <NUM> can additionally or alternatively be implemented as one or more discrete structures having any other suitable size or shape.

<FIG> is a cross section view of an example drip chamber <NUM>. <FIG> are illustrations of a sequence of operating a drop former <NUM> included in the drip chamber <NUM>. The drip chamber <NUM> is a particular example of a drip chamber that employs ultrasonic energy to energize a drop former to stimulate ejection or release of small drops from the drop former. In some embodiments, the drip chamber <NUM> can share features in common with any one or more of the drip chambers shown in <FIG>.

The drip chamber <NUM> includes an electronic component housed within the cap <NUM>. In particular, the electronic component is implemented as or otherwise includes an ultrasonic emitter <NUM> operatively coupled to a drop former <NUM> that is suspended from a cap <NUM>. The ultrasonic emitter <NUM> can, for example, include a piezoelectric, capacitive, or other suitable transducer capable of emitting ultrasonic waves to a surface of the drop former <NUM>. The drop former <NUM> includes a transverse outer surface <NUM> at a distal or lower tip of the drop former. The transverse outer surface <NUM> extends substantially orthogonal to the downward direction, or more generally extends transverse to the direction in which drops are released from the drop former <NUM>. This allows the drops to be released from the drop former <NUM> in a direction generally normal to the outer surface <NUM>. The transverse outer surface <NUM> may be provided using a flared structure, as shown in <FIG>, in which the distal, lower end of the drop former is flared radially outward to provide an increased diameter at its lower end. Alternatively, the drop former <NUM> may be implemented with a solid cylindrical structure (such as a large gauge wire) in which a distal, lower tip provides a transverse surface with sufficient surface area for the ultrasonic emitter to create drops in the manner described herein.

<FIG> also shows an external coupling connector <NUM> which can, for example, permit coupling of the ultrasonic emitter <NUM> to external electronic components, such as an external power source and/or external ultrasonic generator configured to provide an oscillating signal to the ultrasonic emitter <NUM> housed within the drip chamber <NUM>. Although the drip chamber <NUM> is shown as included both an internal ultrasonic emitter <NUM> and external coupling connector <NUM>, in alternate embodiments only one or the other may be used. For example, in some embodiments, all electronics used for emitting waves to the drop former <NUM> can be housed entirely within the cap <NUM>. Alternatively, all the electronics including the ultrasonic emitter <NUM> can be provided externally and coupled to the drop former through one or more external coupling connectors.

The ultrasonic emitter <NUM> can be configured to generate standing waves of an IV fluid <NUM> at the surface of the drop former <NUM> to allow creating of very small drops or droplets that can have a smaller diameter than the transverse surface <NUM>. <FIG> illustrate an example sequence of drop creation at drop former <NUM> using ultrasonic electronics to energize the drop former and create standing waves at the transverse surface <NUM>. In <FIG>, the drop former <NUM> is shown in inverted form to better show the surface <NUM> and wave generation.

<FIG> shows the drop former <NUM> with IV fluid resting on the surface <NUM> when no ultrasonic waves or energy are provided to the surface. In this state, the fluid can form a relatively large clump. In <FIG>, ultrasonic waves are coupled to the surface <NUM> to cause the formation of standing waves which generally cause the clump of IV fluid <NUM> to separate into smaller sections or smaller peaks and valleys. In this state, the IV fluid <NUM> has not yet released from the drop former. In <FIG>, the waves have crested after their amplitudes have increased sufficiently to cause release of one or more small drops or droplets of the IV fluid <NUM>, which can generally have a diameter smaller than a diameter of the transverse surface <NUM> at the tip of the drop former <NUM>. Although the waves are shown with a generally circular or annular pattern in <FIG>, in various implementations the waves and/or drops released from the ultrasonic drop former <NUM> may generally have any appropriate size, shape, or pattern, as desired. For example, the use of ultrasonic electronics may also allow the size, pattern, or rate of drop creation to be fine-tuned by adjusting the waveform (e.g., by adjusting shape, frequency, and/or amplitude of the ultrasonic waves) provided to the transverse outer surface <NUM>.

<FIG> is a cross section view of an example drip chamber <NUM>. The drip chamber <NUM> is a particular example of a drip chamber that employs injected air to stimulate a release of a drop from the drop former. In some embodiments, the drip chamber <NUM> can share features in common with any one or more of the drip chambers shown in <FIG>.

The drip chamber <NUM> includes a gas inlet port <NUM> coupled to a drop former <NUM> via a fluidic pathway to permit an injected gas <NUM> (e.g., sterile air or another gas) to stimulate a release of a small drop from the drop former <NUM>, which can receive an IV fluid from liquid inlet port <NUM>. A gas injection component <NUM> can be coupled to the gas inlet port <NUM> to inject a gas into an interior of the drip chamber, where it can stimulate a surface of the drop former to trigger a release of a drop of IV fluid <NUM>. The gas injection component <NUM> can include, for example, a compressed gas cartridge, or a tubing segment coupled to a pressurized gas tank, a pump, or other source of gas in a facility (e.g., a hospital).

The gas inlet port <NUM> can be operatively coupled to the drop former via a fluidic pathway that permits the injected gas <NUM> to reach the drop former. For example, a gas orifice <NUM> can be provided in the cap immediately above the drop former to permit gas <NUM> injected through the gas inlet port <NUM> to reach the drop former <NUM>. Alternatively, other structures may be used to permit the gas inlet port <NUM> to be operatively coupled to the drop former to stimulate release of drops thereform. In some embodiments, the injected gas may be delivered in a series of bursts timed in synchronization with a predetermined drip rate, which may be fixed or user-programmable. For example, a small disposable compressed gas cartridge may be provided with the drip chamber <NUM> and configured to meter out the injected gas through the gas inlet port in a series of small bursts. This may allow for the desired drip rate while also permitting compressed gas contained within the compressed gas cartridge to last for a duration of use of the drip chamber <NUM>.

<FIG> is a cross section view of an example drip chamber <NUM>. The drip chamber <NUM> is a particular example of a drip chamber that employs a piezoelectric sensor to detect drip rate of drops falling within the drip chamber, which may, for example, permit drops to be counted at a rate faster than the human eye can reliably see. In some embodiments, the drip chamber <NUM> can share features in common with any one or more of the drip chambers shown in <FIG>.

The drip chamber <NUM> includes a piezo electric sensor <NUM> coupled to a container <NUM> to detect drops falling within the container. The piezo electric sensor <NUM> can, for example, include a passive piezo electric material <NUM> that acts as a microphone to detect the impact of drops of the IV fluid <NUM> falling into the container <NUM> from the drop former <NUM>. In the example shown in <FIG>, the piezo electric sensor <NUM> includes one or more electrodes <NUM> coupled to the piezoelectric material <NUM>. The piezoelectric material <NUM> can, for example, be a passive piezo electric material. The electrode(s) <NUM> can be coupled to detection circuitry <NUM> which is configured to measure a signal and/or determine a flow rate by counting a number of drops falling into the container <NUM>. The detection circuitry <NUM> can generally include any one or more analog and/or digital circuits, processor(s), microcontroller(s), and/or other circuitry suitable for processing a signal received from the piezoelectric sensor <NUM>. The detection circuitry <NUM> can, for example, be contained within the same physical module or sensor package as the piezo electric sensor <NUM>, or may be physically separate communicatively coupled to the piezo electric sensor <NUM> through one or more wired and/or wireless interconnections.

The piezo electric sensor <NUM> can be disposed outside of the container <NUM> and outside of the interior cavity <NUM> to insulate the piezo electric sensor <NUM> from physical contact with the IV fluid <NUM> delivered to the patient. The piezoelectric sensor <NUM> can be attached to a sidewall of the container <NUM> to facilitate pickup of the signal from drop impact within the cavity <NUM> by the sensor <NUM>. The piezoelectric sensor <NUM> can also be disposed below a fluid level where the IV fluid is initially primed, for example, below a midway point of the container body. This may also facilitate pickup of the signal of each drop upon impact to be picked up by the sensor, as the IV fluid <NUM> can act as a transmission medium for the acoustic or mechanical impact of falling drops.

<FIG> is a cross section view of an example drip chamber <NUM>. The drip chamber <NUM> is a particular example of a drip chamber that employs a charged electrode to attract polar molecules (e.g., water molecules) in the IV fluid <NUM> and dislodge drops of the IV fluid <NUM> at a volume smaller than may be possible with gravity alone. In some embodiments, the drip chamber <NUM> can share features in common with any one or more of the drip chambers shown in <FIG>.

The drip chamber <NUM> includes an electrode <NUM>, which is disposed sufficiently close to the drop former <NUM> to attract a polar molecule in the IV fluid <NUM> based on a charge applied to or otherwise held in the electrode <NUM>. For example, as shown in <FIG> the electrode <NUM> can be negatively charged, which can attract a positive end of water molecules within the drop former to effect a release of drops. As another example, in some embodiments the electrode <NUM> can be positively charged to attract a negative end of water molecules or other polar molecules in the IV fluid <NUM>. In the example shown in <FIG>, the electrode <NUM> is disposed within the interior cavity <NUM> of the container <NUM> and suspended from the cap <NUM> in a region near the tip of the drop former <NUM>. However, implementations are contemplated in which the electrode <NUM> can be disposed in any other suitable location to permit the electrode to attract polar molecules in the IV fluid <NUM>. For example, in some embodiments the electrode <NUM> can be implemented as all or a portion of the container <NUM> itself. The drop former <NUM> is shown as having a tubular structure in <FIG> but can in various embodiments employ any suitable structure for forming and releasing drops, such as, for example, a pin or wire with a solid distal tip like that shown in <FIG>.

Claim 1:
A drip chamber (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising:
a container (<NUM>) configured to hold an IV fluid (<NUM>);
a drop former (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) suspended over the container (<NUM>) and coupled to an inlet port (<NUM>) to receive the IV fluid (<NUM>) from a reservoir;
characterized in that the drip chamber (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) further comprises
an acoustic emitter operatively coupled to the drop former (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) to stimulate a release of a drop of the IV fluid (<NUM>) from the drop former (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>).