Patent Description:
The present disclosure generally relates to pumps, and, in particular, to peristaltic pumps.

Patients in hospitals often receive medications and medical fluids (e.g., a saline solution or a liquid medication) via infusion using an intravenous ("IV") pump. In some applications, an IV pump uses peristaltic manipulation of a segment of tubing of an IV set to create the flow of medical fluid to the patient.

In document <CIT> a pump for treating a patient is disclosed, comprising: a spring biased plunger biased against a tube for actuation; a cam shaft configured to actuate the spring biased plunger; a lever actuatable between a closed position and an open position; a shaft coupled to the lever, the shaft having a central axis centrally along the length of the shaft, the shaft coupled to the lever to rotate about the central axis in accordance with actuation of the lever; and a lift cam pivotally coupled to the shaft, the lift cam pivoting about a lift cam axis, the lift cam axis of the lift cam being parallel to the central axis of the shaft, and the lift cam engaging the spring biased plunger; and a lift cam pivotally coupled to the shaft, the lift cam pivoting about a lift cam axis, the lift cam axis of the lift cam being parallel to the central axis of the shaft, the lift cam engaging the spring loaded plunger to lift the spring loaded plunger off the cam shaft as the shaft rotates in accordance with actuation of the lever to the open position.

Document <CIT> describes a peristaltic pump for pumping liquids through an elastic tube. In one embodiment the pump comprises a curved concave plate against which an elastic tube is placed. A multi-lobed cam is positioned adjacent the platen and the tube. A plurality of pump fingers are mounted between the tube and the cam in a manner that allows radial movement of the pump fingers. As the cam rotates, the fingers are sequentially pressed against the tube to pump fluid through the tube. The end of the lobe should press against the tube sufficiently to occlude the tube and prevent backflow without over-pressing and damaging the tube. A transverse pinch finger is provided on each pump finger, extending from the tube pressing surface of each pump finger. At the tube occluding position, the pump finger nearly occludes the tube and the pinch finger completes the occlusion without pushing the tube beyond the fully occluded position. A fixed or sliding spring-loaded pinch finger may be used. In a second embodiment, the pump fingers also include pinch fingers and are moved towards and away from a planar platen by a plurality of cams mounted transversely on a rotatable shaft. The pinch fingers operate in the same manner as in the first embodiment.

Document <CIT> discloses an infusion pump system which includes a stepper motor connected to a cam shaft through a reducer gear set. The cam shaft is equipped with several cams placed at various intervals along its circumference. These cams interact with follower fingers that compress sections of an intravenous drip tubing, which runs parallel to the cam shaft. The tubing is manually inserted into the mechanism using a capture plate or door. The operation of the stepper motor, specifically its step rate, controls the flow rate of the fluid through the pump.

The disclosed subject matter relates to peristaltic pumps. In certain embodiments, a peristaltic pump includes a plunger movable to selectively engage a pumping volume of a tubing segment; a camshaft comprising a first plunger cam lobe, wherein the first plunger cam lobe is configured to move the plunger between an engaged position in contact with the pumping volume and a disengaged position spaced apart from the pumping volume; and a first biasing member configured to urge the plunger toward the tubing segment to maintain contact with the tubing segment in the engaged position.

In certain embodiments, a peristaltic pump includes a first plunger movable to selectively engage a pumping volume of a tubing segment; a second plunger movable to selectively engage the pumping volume; a camshaft comprising: a first plunger cam lobe, wherein the first plunger cam lobe is configured to move the first plunger between an engaged position in contact with the pumping volume and a disengaged position spaced apart from the pumping volume; and a second plunger cam lobe, wherein the second plunger cam lobe is configured to move the second plunger between an expansion position to draw fluid flow into the pumping volume and a contraction position to conduct fluid flow from the pumping volume; a first biasing member configured to urge the first plunger toward the tubing segment to maintain contact with the tubing segment in the engaged position; and a second biasing member configured to urge the second plunger toward the tubing segment to contract the pumping volume in the contraction position.

In certain embodiments, a method is disclosed and comprises expanding a peristaltic pumping volume of a tubing segment; and urging a first plunger toward the tubing segment to maintain contact with the tubing segment after the expansion of the pumping volume with a first force.

The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. Like components are labeled with identical element numbers for ease of understanding. Reference numbers may have letter suffixes appended to indicate separate instances of a common element while being referred to generically by the same number without a suffix letter.

While the following description is directed to administration of medical fluid by utilizing the disclosed peristaltic pumps, it is to be understood that this description is only an example of usage and does not limit the scope of the claims. Various aspects of the disclosed peristaltic pumps may be used in any application where it is desirable to administer the flow of fluid.

<FIG> depicts a patient <NUM> receiving an infusion of a medical fluid using an IV pump <NUM>. In the depicted example, the IV pump <NUM> is delivering a medical fluid from a fluid container <NUM> to the patient <NUM>. A fluid container <NUM> is hung at or above the patient's head and connected via an IV set <NUM> to the IV pump module <NUM> and then to the patient <NUM>. In some embodiments, the IV pump <NUM> includes a control unit <NUM> and a pumping module <NUM>.

The pumping module <NUM> can include a peristaltic pump to administer the medical fluid from the fluid container <NUM> to the patient <NUM>.

During operation of the peristaltic pump, it may be desirable to monitor the volume pumped by the peristaltic pump. In some applications, the peristaltic pump can include a measurement phase between a refill phase and a delivery phase.

The disclosed peristaltic pump can incorporate various measurement mechanisms to allow for monitoring the volume pumped by the peristaltic pump. The disclosed peristaltic pump can include feeler mechanisms, biasing members with various levels of force, and/or split plungers. By utilizing the measurement mechanisms disclosed herein, the peristaltic pump can allow for monitoring without a dedicated measurement phase and/or without generating high internal pressures.

The disclosed peristaltic pump overcomes several challenges discovered with respect to certain measurement approaches utilized with peristaltic pumps. One challenge with certain measurement approaches is that during a dedicated measurement phase, a plunger may apply a large force to a fluid volume confined between an upper valve and a lower valve to measure the fluid volume, pressurizing the fluid volume. Accordingly, the upper valve and the lower valve may apply a large force to the tubing that contains the pressurized fluid volume during measurement, which may damage or cause wear to the tubing. Another challenge with certain measurement approaches is that flow may be discontinued during a dedicated measurement phase, promoting out-gassing of dissolved gases in an infusate. Because damage or wear to the tubing can result in tubing material particulate to dislodge from the tubing and enter a patient's bloodstream and out-gassing of dissolved gases can cause embolisms in a patient, it is advantageous to provide measurement mechanisms that allow for measurement of a fluid volume without a dedicated measurement phase and/or without generating high internal pressures. The disclosed peristaltic pumps provide for measurement of a fluid volume without a dedicated measurement phase and/or without generating high internal pressures during a measurement phase.

Examples of peristaltic pumps that allow for measurement of a fluid volume without a dedicated measurement phase and/or without generating high internal pressures are now described.

<FIG> is a perspective view of a peristaltic pump <NUM>, in accordance with various aspects of the present disclosure. <FIG> is a simplified view of the peristaltic pump <NUM> of <FIG>. In the depicted example, the peristaltic pump <NUM> can peristaltically manipulate tubing to create the flow of medical fluid to the patient. In some embodiments, an upstream portion of the tubing is in fluid communication with a source of medical fluid, such as an IV bag or other medical fluid container, and the downstream portion of the tubing is in fluid communication with IV tubing to the patient. In some embodiments, the peristaltic pump <NUM> repeatedly cycles between a filling phase and a delivery phase to administer fluid to the patient. As described herein, the peristaltic pump <NUM> allows for volume measurements without requiring a dedicated measurement phase.

In the depicted example, the peristaltic pump <NUM> includes a plunger <NUM>, an upstream occluder or valve <NUM>, and a downstream occluder or valve <NUM>, each configured to contact and manipulate the tubing to deliver fluid from a fluid source to the patient. In some embodiments, the plunger <NUM>, the upstream valve <NUM>, and the downstream valve <NUM> can move in coordinated, sequential steps to pump fluid through the tubing. The tubing can be formed from a mechanically resilient material. The tubing can be supported by a backer <NUM> as the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> contact and manipulate the tubing.

As described herein, the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> can be moved by one or more actuators. The movement of actuators that control the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> can be coordinated, or otherwise sequenced. In the depicted example, the movement of the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> is cyclical.

<FIG> is an exploded view of components of the peristaltic pump <NUM> of <FIG>. With reference to <FIG>, the peristaltic pump <NUM> can include a camshaft <NUM> to actuate the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM>. In the depicted example, the camshaft <NUM> includes one or more cam lobes, such as a plunger cam lobe <NUM>, an upstream valve cam lobe <NUM>, and/or a downstream valve cam lobe <NUM>.

As described herein, the geometry of the respective cam lobes can be shaped or modified to allow for a desired actuation or movement of the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM>. For example, portions of a cam lobe with a larger radius can allow for the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> to open or lift further from the tubing and/or backer <NUM> while portions of a cam lobe with a smaller radius can allow the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> to closer or otherwise be urged toward the tubing and/or backing.

In some embodiments, the cam lobes of the camshaft <NUM> actuate one or more rockers to control the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM>. As can be appreciated, the geometry of the rockers described herein can be configured to provide a desired actuation ratio between the movement of the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> and the geometry of the plunger cam lobe <NUM>, upstream valve cam lobe <NUM>, and/or the downstream valve cam lobe <NUM>, respectively. As described herein, certain rockers, such as the second plunger valve rocker 111b may move independently or may otherwise not be directly actuated by the camshaft <NUM>. The first plunger valve rocker 111a, the second plunger valve rocker 111b, the upstream valve rocker <NUM>, and/or the downstream valve rocker <NUM> can each rotate or pivot about a pivot shaft <NUM>.

In the depicted example, biasing members, such as springs can urge the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> toward the tubing and/or the backer <NUM>. In some embodiments, biasing members can act upon the rockers to urge the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> toward the tubing and/or the backer <NUM>. During operation, actuation of the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> by the camshaft can overcome the biasing force applied by the biasing members to lift or otherwise actuate the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM>.

Further, the arrangement or phasing of the cam lobes about the camshaft <NUM> can be modified to provide a desired sequence of actuation or movement of the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> as the camshaft <NUM> is rotated. For example, the plunger cam lobe <NUM>, the upstream valve cam lobe <NUM>, and/or the downstream valve cam lobe <NUM> can each have a cam profile and/or a relative arrangement that eliminates or otherwise does not include a dedicated measurement phase where the plunger <NUM> is actuated against a pumping volume of the tubing closed by the upstream valve <NUM> and the downstream valve <NUM>.

In the depicted example, the peristaltic pump <NUM> includes a split rocker arrangement with a first plunger valve rocker 111a directly coupled to the plunger <NUM> and a second plunger valve rocker 111b configured to act upon the first plunger valve rocker 111a. In some embodiments, the first plunger valve rocker 111a is spaced apart, decoupled, not aligned, or otherwise not directly actuated by the plunger cam lobe <NUM>. As can be appreciated, the first plunger valve rocker 111a and therefore the plunger <NUM> may be independently moved or actuated separate from the actuation of the plunger cam lobe <NUM>.

In the depicted example, a first plunger biasing member 164a can act upon the first plunger valve rocker 111a to urge the plunger <NUM> toward the tubing and/or the backer <NUM>. As can be appreciated, the biasing force applied by the first plunger biasing member 164a to the first plunger valve rocker 111a and the plunger <NUM> can be a constant or chronic force that is independent of the rotation of the camshaft <NUM>. During operation, the arrangement of the first plunger valve rocker 111a and the first plunger biasing member 164a can allow the plunger <NUM> to maintain contact with the tubing. As can be appreciated, the force applied by the first plunger biasing member 164a can be sufficient for the plunger <NUM> to maintain contact with the tubing without damaging the tubing.

In the depicted example, the position of the plunger <NUM> can be used to determine the volume of fluid administered by the peristaltic pump <NUM>. During operation, the height of the plunger <NUM> can be used to determine the height of the pumping volume within the tubing, which can be used to determine the volume of fluid administered by the peristaltic pump <NUM>. Advantageously, the arrangement of the first plunger biasing member 164a and the first plunger valve rocker 111a allows for the plunger <NUM> to permit volume measurements without exerting excess force or requiring a dedicated measurement phase.

In the depicted example, the second plunger valve rocker 111b is aligned, positioned, or otherwise configured to be actuated by the plunger cam lobe <NUM>. During operation, a portion of the second plunger valve rocker 111b can engage or slide along the cam profile of the plunger cam lobe <NUM> to translate the geometry of the cam profile into movement of the second plunger valve rocker 111b. In some embodiments, during certain movements (e.g., during a delivery phase of operation) the second plunger valve rocker 111b can engage with the first plunger valve rocker 111a to move the plunger <NUM> relative to the tubing in response to actuation from the plunger cam lobe <NUM>.

In the depicted example, a second plunger biasing member 164b can act upon the second plunger valve rocker 111b to urge the second plunger valve rocker 111b toward the first plunger valve rocker 111a. During certain portions of operation (e.g., the delivery phase of operation) the second plunger biasing member 164b can force the second plunger valve rocker 111b to engage with the first plunger valve rocker 111a and urge the plunger <NUM> toward the tubing and/or the backer <NUM>. As can be appreciated, actuation of the second plunger valve rocker 111b by the rotation of the plunger cam lobe <NUM> can overcome the biasing force to disengage the second plunger valve rocker 111b from the first plunger valve rocker 111a. Accordingly, the biasing force applied by the second plunger biasing member 164b to the first plunger valve rocker 111a and/or the plunger <NUM> can vary in response to the actuation of the second plunger valve rocker 111b by the rotation of the plunger cam lobe <NUM>. During operation, the arrangement of the second plunger valve rocker 111b and the second plunger biasing member 164b relative to the first plunger valve rocker 111a and the first plunger biasing member 164a allows the peristaltic pump <NUM> to apply additional force to the plunger during certain portions of operation (e.g., the delivery phase) while allowing the first plunger biasing member 164a to maintain a chronic biasing force against the tubing. In some embodiments, the force applied by the second plunger biasing member 164b is higher than the biasing force applied by the first plunger biasing member 164a. Optionally, the force applied by the second plunger biasing member 164b is sufficient to allow fluid delivery. In some embodiments, the first plunger biasing member 164a and the second plunger biasing member 164b cooperatively provide sufficient force to allow for fluid delivery.

In some embodiments, an upstream valve rocker <NUM> is coupled to the upstream valve <NUM> and can move the upstream valve <NUM> in response to actuation from the upstream valve cam lobe <NUM>. During operation, a portion of the upstream valve rocker <NUM> can engage or slide along the cam profile of the upstream valve cam lobe <NUM> to translate the geometry of the cam profile into movement of the upstream valve <NUM> relative to the tubing.

As illustrated, an upstream valve biasing member <NUM> can act upon the upstream valve rocker <NUM> to urge the upstream valve <NUM> toward the tubing and/or the backer <NUM>. As can be appreciated, actuation of the upstream valve rocker <NUM> by the rotation of the upstream valve cam lobe <NUM> can overcome the biasing force to lift or otherwise actuate the upstream valve <NUM>.

Similarly, a downstream valve rocker <NUM> is coupled to the downstream valve <NUM> and can move the downstream valve <NUM> in response to actuation from the downstream valve cam lobe <NUM>. During operation, a portion of the downstream valve rocker <NUM> can engage or slide along the cam profile of the downstream valve cam lobe <NUM> to translate the geometry of the cam profile into movement of the downstream valve <NUM> relative to the tubing.

Similarly, a downstream valve biasing member <NUM> can act upon the downstream valve rocker <NUM> to urge the downstream valve <NUM> toward the tubing and/or the backer <NUM>. As can be appreciated, actuation of the downstream valve rocker <NUM> by the rotation of the downstream valve cam lobe <NUM> can overcome the biasing force to lift or otherwise actuate the downstream valve <NUM>.

<FIG> is an illustration of the peristaltic pump <NUM> of <FIG> in a filling phase, in accordance with various aspects of the present disclosure. During operation, the tubing <NUM> draws in medical fluid <NUM> during the filling phase. As illustrated, the plunger <NUM> is withdrawn or retracted from a compressed portion of the tubing <NUM>, allowing the tubing walls <NUM> to resiliently expand the pumping volume <NUM> to an original or expanded state.

In the depicted example, the expansion of the pumping volume <NUM> draws in fluid into the pumping volume <NUM>. The mechanical resilience of the tubing <NUM> allows the tubing walls <NUM> to expand from a compressed state to an expanded state, expanding the pumping volume <NUM>. The rate at which the pumping volume <NUM> rebounds from a compressed state to an expanded state can determine the amount of fluid that can be drawn into the pumping volume <NUM> in a given period of time.

As illustrated, during the expansion of the pumping volume <NUM>, the downstream portion <NUM> of the tubing <NUM> is blocked, pinched, or otherwise occluded by the downstream valve <NUM> to prevent or restrict backflow or contamination of fluid into the pumping volume <NUM>.

In the depicted example, the downstream valve <NUM> is actuated, moved downward, or otherwise engaged to compress the tubing walls <NUM> of the tubing <NUM> at the downstream portion <NUM> to occlude flow through the downstream portion <NUM> of the tubing <NUM>. The downstream valve <NUM> can include a beveled engagement portion to contact the tubing <NUM>. When engaged, the downstream valve <NUM> can prevent or restrict flow or fluid communication from the downstream portion <NUM> into the pumping volume <NUM>.

During the expansion of the pumping volume <NUM>, medical fluid <NUM> is drawn into pumping volume <NUM> from the upstream portion <NUM> of the tubing <NUM>. As illustrated, during the expansion of the pumping volume <NUM>, the upstream portion <NUM> of the tubing <NUM> is unobstructed by the upstream valve <NUM>, permitting medical fluid <NUM> into the pumping volume <NUM>. During operation, the upstream valve <NUM> is withdrawn or retracted from a compressed portion of the tubing <NUM>, allowing the tubing walls <NUM> to resiliently expand the upstream portion <NUM> to an original or expanded state.

In the depicted example, the expansion of the upstream portion <NUM> permits the flow of medical fluid <NUM> into the pumping volume <NUM>. The mechanical resilience of the tubing <NUM> allows the tubing walls <NUM> to expand from a compressed state to an expanded state, expanding the cross-sectional profile or flow area of the upstream portion <NUM>. The amount of medical fluid <NUM> drawn into the pumping volume <NUM> during the filling phase can be determined by the timing and sequence of the plunger <NUM>, the upstream valve <NUM>, a viscosity of the medical fluid <NUM>, and the mechanical properties of the tubing <NUM>.

Advantageously, and as described herein, the first plunger biasing member 164a can maintain a constant or chronic force to allow the plunger <NUM> to maintain contact with the tubing <NUM> during the filling phase to permit measurement of the pumping volume. In the depicted example, the force applied by the first plunger biasing member 164a can be sufficient to maintain contact with the tubing <NUM> while allowing for the pumping volume <NUM> to be filled.

<FIG> is an illustration of the peristaltic pump <NUM> of <FIG> in a delivery phase, in accordance with various aspects of the present disclosure. <FIG> is an illustration of the peristaltic pump <NUM> of <FIG> in a delivered position, in accordance with various aspects of the present disclosure. With reference to <FIG>, the peristaltic pump <NUM> delivers medical fluid through a downstream portion <NUM> to a downstream location, such as a patient. As illustrated, the plunger <NUM> is actuated, moved downward, or otherwise engaged to compress the tubing walls <NUM> of the tubing <NUM> to compress the pumping volume <NUM> to a compressed or reduced state.

During operation, the compression of the pumping volume <NUM> expels or otherwise administers fluid from the pumping volume <NUM> to a downstream location. The rate of administration of the medical fluid can be controlled by the force and velocity of the plunger <NUM>.

As described herein, the first plunger biasing member 164a and the second plunger biasing member 164b cooperatively force the plunger <NUM> to compress the pumping volume <NUM> to a compressed or reduced state. In some embodiments, the second plunger biasing member 164b can force the plunger <NUM> to compress the pumping volume <NUM> to a compressed or reduced state without the cooperation of the first plunger biasing member 164a.

During administration, the upstream portion <NUM> of the tubing <NUM> is blocked, pinched, or otherwise occluded by the upstream valve <NUM> to prevent or restrict inadvertent fluid flow into the pumping volume <NUM> and to prevent or restrict backflow of fluid into the medical container from the pumping volume <NUM>.

In the depicted example, the upstream valve <NUM> is actuated, moved downward, or otherwise engaged to compress the tubing walls <NUM> of the tubing <NUM> at the upstream portion <NUM> to occlude flow through the upstream portion <NUM> of the tubing <NUM>. The upstream valve <NUM> can include a beveled engagement portion to contact the tubing <NUM>. When engaged, the upstream valve <NUM> can prevent or restrict flow or fluid communication between the upstream portion <NUM> and the pumping volume <NUM>.

During the compression of the pumping volume <NUM>, medical fluid is forced from the pumping volume <NUM> to a downstream location through the downstream portion <NUM> of the tubing <NUM>. As illustrated, during the compression of the pumping volume <NUM>, the downstream portion <NUM> of the tubing <NUM> is unobstructed by the downstream valve <NUM>, permitting medical fluid <NUM> to flow out of the tubing <NUM>. During operation, the downstream valve <NUM> is withdrawn or retracted from a compressed portion of the tubing <NUM>, allowing the tubing walls <NUM> to resiliently expand the downstream portion <NUM> to an original or expanded state.

In the depicted example, the expansion of the downstream portion <NUM> permits the flow of medical fluid <NUM> out of the pumping volume <NUM>. The mechanical resilience of the tubing <NUM> allows the tubing walls <NUM> to expand from a compressed state to an expanded state, expanding the cross-sectional profile or flow area of the downstream portion <NUM>. The rate at which the downstream portion <NUM> rebounds from a compressed state to an expanded state can limit the size of the flow area or opening out of the pumping volume <NUM>. Therefore, the rate at which the downstream portion <NUM> rebounds from a compressed state to an expanded state can limit or restrict the amount of fluid that can flow out of the pumping volume <NUM> in a given period of time.

The amount of medical fluid <NUM> administered from the pumping volume <NUM> during the delivery phase can be determined by the timing and sequence of the plunger <NUM>, the downstream valve <NUM> and the mechanical properties of the tubing <NUM>.

<FIG> is a perspective view of a peristaltic pump <NUM>, in accordance with various aspects of the present disclosure. <FIG> is a simplified view of the peristaltic pump <NUM> of <FIG>. <FIG> is a back view of the peristaltic pump <NUM> of <FIG>. <FIG> is an exploded view of components of the peristaltic pump <NUM> of <FIG>. With reference to <FIG>, the peristaltic pump <NUM> can independently control the operation of the first plunger valve rocker 111a and the second plunger valve rocker 111b to control the spring or biasing force applied to the plunger <NUM>. Advantageously, the peristaltic pump <NUM> can be configured to permit volume measurements without exerting excess force during a measurement phase.

As previously described, the peristaltic pump <NUM> can include a camshaft <NUM> to actuate the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM>. In the depicted example, the camshaft <NUM> includes one or more cam lobes, such as a first plunger cam lobe 154a, a second plunger cam lobe 154b, an upstream valve cam lobe <NUM>, and/or a downstream valve cam lobe <NUM>.

In the depicted example, the peristaltic pump <NUM> includes a split rocker arrangement with a first plunger valve rocker 111a directly coupled to the plunger <NUM> and a second plunger valve rocker 111b configured to act upon the first plunger valve rocker 111a. In the depicted example, the first plunger valve rocker 111a is aligned, positioned, or otherwise configured to be actuated by the first plunger cam lobe 154a. During operation, a portion of the first plunger valve rocker 111a can engage or slide along the cam profile of the first plunger cam lobe 154a to translate the geometry of the cam profile into movement of the first plunger valve rocker 111a and the plunger <NUM>. As can be appreciated, the first plunger valve rocker 111a and therefore the plunger <NUM> may be independently moved or actuated separate from the actuation of the second plunger valve rocker 111b during certain portions of operation (e.g., a measurement phase).

In the depicted example, a first plunger biasing member 164a can act upon the first plunger valve rocker 111a to urge the plunger <NUM> toward the tubing and/or the backer <NUM>. As can be appreciated, actuation of the first plunger valve rocker 111a by the rotation of the first plunger cam lobe 154a can overcome the biasing force to lift or otherwise actuate the plunger <NUM> independent of the second plunger valve rocker 111b. Therefore, the force applied to the plunger <NUM> can vary in response to the actuation of the first plunger valve rocker 111a by the rotation of the first plunger cam lobe 154a.

During operation, the arrangement of the first plunger valve rocker 111a, the first plunger cam lobe 154a, and the first plunger biasing member 164a can allow the plunger <NUM> to contact the tubing during a measurement phase without administering the fluid within the pumping volume or damaging the tubing.

In the depicted example, the second plunger valve rocker 111b is aligned, positioned, or otherwise configured to be actuated by the second plunger cam lobe 154b. During operation, a portion of the second plunger valve rocker 111b can engage or slide along the cam profile of the second plunger cam lobe 154b to translate the geometry of the cam profile into movement of the second plunger valve rocker 111b. In some embodiments, during certain movements (e.g., during a delivery phase of operation) the second plunger valve rocker 111b can engage with the first plunger valve rocker 111a to move the plunger <NUM> relative to the tubing in response to actuation from the second plunger cam lobe 154b.

In the depicted example, a second plunger biasing member 164b can act upon the second plunger valve rocker 111b to urge the second plunger valve rocker 111b toward the first plunger valve rocker 111a. During certain portions of operation (e.g., the delivery phase of operation) the second plunger biasing member 164b can force the second plunger valve rocker 111b to engage with the first plunger valve rocker 111a and urge the plunger <NUM> toward the tubing and/or the backer <NUM>. As can be appreciated, actuation of the second plunger valve rocker 111b by the rotation of the second plunger cam lobe 154b can overcome the biasing force to disengage the second plunger valve rocker 111b from the first plunger valve rocker 111a. Accordingly, the biasing force applied by the second plunger biasing member 164b to the first plunger valve rocker 111a and/or the plunger <NUM> can vary in response to the actuation of the second plunger valve rocker 111b by the rotation of the second plunger cam lobe 154b. During operation, the arrangement of the second plunger valve rocker 111b and the second plunger biasing member 164b relative to the first plunger valve rocker 111a and the first plunger biasing member 164a allows the peristaltic pump <NUM> to apply additional force to the plunger during certain portions of operation (e.g., the delivery phase) while allowing the a reduced force during other portions of operation (e.g., the measurement phase). In some embodiments, the force applied by the second plunger biasing member 164b is higher than the biasing force applied by the first plunger biasing member 164a. Optionally, the force applied by the second plunger biasing member 164b is sufficient to allow fluid delivery. In some embodiments, the first plunger biasing member 164a and the second plunger biasing member 164b cooperatively provide sufficient force to allow for fluid delivery.

Further, the arrangement or phasing of the first plunger cam lobe 154a and the second plunger cam lobe 154b about the camshaft <NUM> can be modified to provide a desired sequence of actuation or movement of the first plunger valve rocker 111a and the second plunger valve rocker 111b as the camshaft <NUM> is rotated. For example, the cam lobes can each have a cam profile and/or a relative arrangement that includes a measurement phase that applies the plunger to the tubing with a reduced spring force.

In the depicted example, the expansion of the pumping volume <NUM> draws in fluid into the pumping volume <NUM>. As illustrated, during the expansion of the pumping volume <NUM>, the downstream portion <NUM> of the tubing <NUM> is blocked, pinched, or otherwise occluded by the downstream valve <NUM> to prevent or restrict backflow or contamination of fluid into the pumping volume <NUM>.

In the depicted example, the expansion of the upstream portion <NUM> permits the flow of medical fluid <NUM> into the pumping volume <NUM>. Advantageously, and as described herein, the arrangement of the first plunger cam lobe 154a and the second plunger cam lobe 154b can prevent the first plunger biasing member 164a and the second plunger biasing member from applying force to the plunger <NUM> and/or the tubing <NUM> during the filling phase.

<FIG> is an illustration of the peristaltic pump <NUM> of <FIG> in an initial or measurement position, in accordance with various aspects of the present disclosure. After filling, the volume of medical fluid within the pumping volume <NUM> can be measured. As illustrated, the plunger <NUM> is used to measure the height of the pumping volume <NUM> and/or the tubing <NUM> to determine the volume of medical fluid within the pumping volume <NUM>.

During the measurement phase, the downstream portion <NUM> of the tubing <NUM> remains blocked, pinched, or otherwise occluded by the downstream valve <NUM> to prevent or restrict backflow or contamination of fluid into the pumping volume <NUM>. Further, the upstream portion <NUM> of the tubing <NUM> is blocked, pinched, or otherwise occluded by the upstream valve <NUM> to prevent or restrict inadvertent fluid flow into the pumping volume <NUM> and to prevent or restrict backflow of fluid into the medical container from the pumping volume <NUM>.

Further, during measurement, the first plunger biasing member 164a applies a force to the plunger <NUM> to allow the plunger <NUM> to contact the tubing <NUM> to determine the height of the tubing <NUM> and/or the pumping volume <NUM>. In the depicted example, the force applied by the first plunger biasing member 164a can be sufficient to maintain contact with the tubing <NUM> without creating excess pressure within the pumping volume.

During the compression of the pumping volume <NUM>, medical fluid is forced from the pumping volume <NUM> to a downstream location through the downstream portion <NUM> of the tubing <NUM>.

<FIG> is a simplified perspective view of a peristaltic pump <NUM>, in accordance with various aspects of the present disclosure. <FIG> is a top view of the peristaltic pump <NUM> of <FIG>. <FIG> is a back view of the peristaltic pump <NUM> of <FIG>. With reference to <FIG>, the peristaltic pump <NUM> can independently control the operation of a first plunger 110a and a second plunger 110b to facilitate measurement of the volume within the tubing and to control the contact area and force applied to the tubing. Advantageously, the configuration of the peristaltic pump <NUM> can permit volume measurements without exerting excess force during a measurement phase.

In the depicted example, the peristaltic pump <NUM> includes a first plunger 110a, a second plunger 110b, an upstream occluder or valve <NUM>, and a downstream occluder or valve <NUM>, each configured to contact and manipulate the tubing to deliver fluid from a fluid source to the patient. In some embodiments, the first plunger 110a, the second plunger 110b, the upstream valve <NUM>, and the downstream valve <NUM> can move in coordinated, sequential steps to pump fluid through the tubing.

In some embodiments, the first plunger 110a can be configured to contact the tubing to measure the volume within the pumping volume. The second plunger 110b can be configured to contact the tubing to administer fluid during a delivery phase of operation. As illustrated, the first plunger 110a and the second plunger 110b can have different geometries to vary the contact area in contact with the tubing during operation. As illustrated, the first plunger 110a can have a smaller contact area with the tubing compared to the second plunger 110b. In some embodiments, the first plunger 110a and the second plunger 110b can have similar or same sized contact areas. Further, as described herein, the first plunger 110a and the second plunger 110b can apply different or varying forces to the tubing.

As described herein, the first plunger 110a, the second plunger 110b, the upstream valve <NUM>, and/or the downstream valve <NUM> can be moved by one or more actuators.

<FIG> is an exploded view of components of the peristaltic pump <NUM> of <FIG>.

In the depicted example, the peristaltic pump <NUM> includes a split rocker arrangement with a first plunger valve rocker 111a directly coupled to the first plunger 110a and a second plunger valve rocker 111b directly coupled to the second plunger 110b. In the depicted example, the first plunger valve rocker 111a is aligned, positioned, or otherwise configured to be actuated by the first plunger cam lobe 154a. During operation, a portion of the first plunger valve rocker 111a can engage or slide along the cam profile of the first plunger cam lobe 154a to translate the geometry of the cam profile into movement of the first plunger valve rocker 111a and the first plunger 110a. As can be appreciated, the first plunger valve rocker 111a and therefore the first plunger 110a may be independently moved or actuated separate from the actuation of the second plunger valve rocker 111b and the second plunger 110b during certain portions of operation (e.g., a measurement phase).

In the depicted example, a first plunger biasing member 164a can act upon the first plunger valve rocker 111a to urge the first plunger 110a toward the tubing and/or the backer <NUM>. As can be appreciated, actuation of the first plunger valve rocker 111a by the rotation of the first plunger cam lobe 154a can overcome the biasing force to lift or otherwise actuate the first plunger 110a independent of the second plunger valve rocker 111b and the second plunger 110b. Therefore, the force applied to the first plunger 110a can vary in response to the actuation of the first plunger valve rocker 111a by the rotation of the first plunger cam lobe 154a.

During operation, the arrangement of the first plunger valve rocker 111a, the first plunger cam lobe 154a, and the first plunger biasing member 164a can allow the first plunger 110a to contact the tubing during a measurement phase with a reduced contact area and without administering the fluid within the pumping volume or damaging the tubing.

In the depicted example, the second plunger valve rocker 111b is aligned, positioned, or otherwise configured to be actuated by the second plunger cam lobe 154b. During operation, a portion of the second plunger valve rocker 111b can engage or slide along the cam profile of the second plunger cam lobe 154b to translate the geometry of the cam profile into movement of the second plunger valve rocker 111b and the second plunger 110b. As can be appreciated, the second plunger valve rocker 111b and therefore the second plunger 110b may be independently moved or actuated separate from the actuation of the first plunger valve rocker 111a and the first plunger 110a during certain portions of operation (e.g., a delivery phase). In some embodiments, during certain movements (e.g., during a delivery phase of operation) the second plunger valve rocker 111b can move in tandem with the first plunger valve rocker 111a to move both the first plunger 110a and the second plunger 110b.

In the depicted example, a second plunger biasing member 164b can act upon the second plunger valve rocker 111b to urge the second plunger 110b toward the tubing and/or the backer <NUM>. As can be appreciated, actuation of the second plunger valve rocker 111b by the rotation of the second plunger cam lobe 154b can overcome the biasing force to lift or otherwise actuate the second plunger 110b independent of the first plunger valve rocker 111a and the first plunger 110a. Therefore, the force applied to the second plunger 110b can vary in response to the actuation of the second plunger valve rocker 111b by the rotation of the second plunger cam lobe 154b.

During operation, the arrangement of the second plunger valve rocker 111b and the second plunger biasing member 164b relative to the first plunger valve rocker 111a and the first plunger biasing member 164a allows the peristaltic pump <NUM> to apply additional force to the tubing via the first plunger 110a and the second plunger 110b during certain portions of operation (e.g., the delivery phase) while allowing the a reduced force via the first plunger 110a during other portions of operation (e.g., the measurement phase). In some embodiments, the force applied by the second plunger biasing member 164b to the second plunger 110b is higher than the biasing force applied by the first plunger biasing member 164a to the first plunger 110a. Optionally, the force applied by the second plunger biasing member 164b to the second plunger 110b is sufficient to allow fluid delivery. In some embodiments, the first plunger biasing member 164a and the second plunger biasing member 164b cooperatively provide sufficient force via the first plunger 110a and the second plunger 110b to allow for fluid delivery.

Further, the arrangement or phasing of the first plunger cam lobe 154a and the second plunger cam lobe 154b about the camshaft <NUM> can be modified to provide a desired sequence of actuation or movement of the first plunger 110a and the second plunger 110b as the camshaft <NUM> is rotated. For example, the cam lobes can each have a cam profile and/or a relative arrangement that includes a measurement phase that applies the first plunger 110a to the tubing with a reduced spring force and a delivery phase that applies the second plunger 110b with additional force.

<FIG> is an illustration of the peristaltic pump <NUM> of <FIG> in a filling phase, in accordance with various aspects of the present disclosure. During operation, the tubing <NUM> draws in medical fluid <NUM> during the filling phase. As illustrated, the first plunger 110a and the second plunger 110b are withdrawn or retracted from a compressed portion of the tubing <NUM>, allowing the tubing walls <NUM> to resiliently expand the pumping volume <NUM> to an original or expanded state.

In the depicted example, the expansion of the upstream portion <NUM> permits the flow of medical fluid <NUM> into the pumping volume <NUM>. Advantageously, and as described herein, the arrangement of the first plunger cam lobe 154a and the second plunger cam lobe 154b can prevent the first plunger biasing member 164a and the second plunger biasing member from applying force to the first plunger 110a, the second plunger 110b, and/or the tubing <NUM> during the filling phase.

<FIG> is an illustration of the peristaltic pump <NUM> of <FIG> in a measurement position, in accordance with various aspects of the present disclosure. After filling, the volume of medical fluid within the pumping volume <NUM> can be measured. As illustrated, the first plunger 110a is used to measure the height of the pumping volume <NUM> and/or the tubing <NUM> to determine the volume of medical fluid within the pumping volume <NUM>.

Further, during measurement, the first plunger biasing member 164a applies a force to the first plunger 110a to allow the first plunger 110a to contact the tubing <NUM> to determine the height of the tubing <NUM> and/or the pumping volume <NUM>. In the depicted example, the force applied by the first plunger biasing member 164a via the first plunger 110a can be sufficient to maintain contact with the tubing <NUM> without creating excess pressure within the pumping volume.

<FIG> is an illustration of the peristaltic pump <NUM> of <FIG> in a delivery phase, in accordance with various aspects of the present disclosure. <FIG> is an illustration of the peristaltic pump <NUM> of <FIG> in a delivered position, in accordance with various aspects of the present disclosure. With reference to <FIG>, the peristaltic pump <NUM> delivers medical fluid through a downstream portion <NUM> to a downstream location, such as a patient. As illustrated, the first plunger 110a and the second plunger 110b are actuated, moved downward, or otherwise engaged to compress the tubing walls <NUM> of the tubing <NUM> to compress the pumping volume <NUM> to a compressed or reduced state.

During operation, the compression of the pumping volume <NUM> expels or otherwise administers fluid from the pumping volume <NUM> to a downstream location. The rate of administration of the medical fluid can be controlled by the force and velocity of the first plunger 110a and the second plunger 110b.

As described herein, the first plunger biasing member 164a and the second plunger biasing member 164b cooperatively force the first plunger 110a and the second plunger 110b, respectively, to compress the pumping volume <NUM> to a compressed or reduced state. In some embodiments, the second plunger biasing member 164b can force the second plunger 110b to compress the pumping volume <NUM> to a compressed or reduced state without the cooperation of the first plunger biasing member 164a or the first plunger 110a.

<FIG> is a perspective view of a peristaltic pump <NUM>, in accordance with various aspects of the present disclosure. <FIG> is a simplified view of the peristaltic pump <NUM> of <FIG>. In the depicted example, the peristaltic pump <NUM> includes a feeler pin <NUM> to measure the volume of the fluid being delivered to the patient. In the depicted example, the peristaltic pump <NUM> includes a plunger <NUM>, an upstream occluder or valve <NUM>, and a downstream occluder or valve <NUM>, each configured to contact and manipulate the tubing to deliver fluid from a fluid source to the patient. Advantageously, the configuration of the peristaltic pump <NUM> can permit volume measurements without a dedicated measurement phase.

In the depicted example, the peristaltic pump <NUM> can include a camshaft <NUM> to actuate the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM>. In the depicted example, the camshaft <NUM> includes one or more cam lobes, such as a plunger cam lobe <NUM>, an upstream valve cam lobe <NUM>, and/or a downstream valve cam lobe <NUM>.

As described herein, the geometry of the respective cam lobes can be shaped or modified to allow for a desired actuation or movement of the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM>. In some embodiments, the cam lobes of the camshaft <NUM> actuate one or more rockers to control the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM>.

In the depicted example, biasing members, such as springs can urge the plunger <NUM>, the upstream valve <NUM>, and/or the downstream valve <NUM> toward the tubing and/or the backer <NUM>.

In the depicted example, the peristaltic pump <NUM> includes a single rocker arrangement with a plunger valve rocker <NUM> directly coupled to the plunger <NUM>. In the depicted example, the plunger valve rocker <NUM> is aligned, positioned, or otherwise configured to be actuated by the plunger cam lobe <NUM>. During operation, a portion of the plunger valve rocker <NUM> can engage or slide along the cam profile of the plunger cam lobe <NUM> to translate the geometry of the cam profile into movement of the plunger valve rocker <NUM> and the plunger <NUM>. In the depicted example, a plunger biasing member <NUM> can act upon the plunger valve rocker <NUM> to urge the plunger <NUM> toward the tubing and/or the backer <NUM>. As can be appreciated, actuation of the plunger valve rocker <NUM> by the rotation of the plunger cam lobe <NUM> can overcome the biasing force to lift or otherwise actuate the plunger <NUM>. Therefore, the force applied to the plunger <NUM> can vary in response to the actuation of the plunger valve rocker <NUM> by the rotation of the plunger cam lobe <NUM>.

In some embodiments, an upstream valve rocker <NUM> is coupled to the upstream valve <NUM> and can move the upstream valve <NUM> in response to actuation from the upstream valve cam lobe <NUM>. As illustrated, an upstream valve biasing member <NUM> can act upon the upstream valve rocker <NUM> to urge the upstream valve <NUM> toward the tubing and/or the backer <NUM>.

Similarly, a downstream valve rocker <NUM> is coupled to the downstream valve <NUM> and can move the downstream valve <NUM> in response to actuation from the downstream valve cam lobe <NUM>. Similarly, a downstream valve biasing member <NUM> can act upon the downstream valve rocker <NUM> to urge the downstream valve <NUM> toward the tubing and/or the backer <NUM>.

<FIG> is a perspective view of the feeler pin <NUM> of the peristaltic pump <NUM> of <FIG>. With reference to <FIG>, <FIG>, and <FIG>, the feeler pin <NUM> can determine the volume of fluid administered by the peristaltic pump <NUM>. During operation, the feeler pin <NUM> can be used to determine the height of the pumping volume within the tubing <NUM>, which can be used to determine the volume of the fluid administered by the peristaltic pump <NUM>.

In the depicted example, the feeler pin <NUM> can extend through the plunger <NUM> to contact the tubing <NUM> disposed between the plunger <NUM> and the backer <NUM>. As illustrated, the feeler pin <NUM> can extend through a slot <NUM> formed through the plunger <NUM>. In some embodiments, the feeler pin <NUM> has a rounded tip to contact the tubing <NUM>.

During operation, the feeler pin <NUM> can move with the tubing <NUM> as the height of the pumping volume changes. In some embodiments, the feeler pin <NUM> can include a biasing member <NUM> configured to urge the feeler pin <NUM> toward the tubing <NUM>, allowing the feeler pin <NUM> to maintain contact with the tubing during operation. As can be appreciated, the biasing force of the biasing member <NUM> can be sufficient to maintain contact with the tubing <NUM> without exerting excess force on the tubing. Optionally, the biasing member <NUM> can exert the biasing force against the feeler pin <NUM> via a feeler plate <NUM>. An opposite end of the biasing member <NUM> can engage against a feeler pin bracket <NUM>.

In some embodiments, the feeler pin <NUM> is coupled to the peristaltic pump <NUM> via the feeler pin bracket <NUM>. The feeler pin bracket <NUM> can include a passage to support the feeler pin <NUM> during operation. Optionally, the feeler pin bracket <NUM> can constrain the movement of the feeler pin <NUM> in a single measurement direction. For example, the feeler pin bracket <NUM> can constrain the movement of the feeler pin <NUM> in an axis perpendicular to the longitudinal axis of the tubing <NUM>.

In the depicted example, the peristaltic pump <NUM> can measure the position or height of the feeler pin <NUM> to determine the height of the pumping volume in the tubing <NUM>. As illustrated, the peristaltic pump <NUM> can include a position transducer <NUM> to detect the position of the feeler pin <NUM>. The feeler pin <NUM> can include a trigger portion <NUM> that provide a signal or identifiable portion of the position transducer <NUM>. Optionally, the trigger portion <NUM> can be magnetic and provide a signal to the position transducer <NUM>. The position transducer <NUM> can be mounted parallel to the direction of travel of the feeler pin <NUM> via a mounting bracket <NUM>. The height or position of the feeler pin <NUM> can be utilized to determine the volume of the pumping volume within the tubing <NUM>.

<FIG> is an illustration of the peristaltic pump <NUM> of <FIG> in a filling phase, in accordance with various aspects of the present disclosure. During operation, the tubing <NUM> draws in medical fluid <NUM> during the filling phase. In the depicted example, the expansion of the pumping volume <NUM> draws in fluid into the pumping volume <NUM>.

In the depicted example, the downstream valve <NUM> is actuated, moved downward, or otherwise engaged to compress the tubing walls <NUM> of the tubing <NUM> at the downstream portion <NUM> to occlude flow through the downstream portion <NUM> of the tubing <NUM>. During the expansion of the pumping volume <NUM>, medical fluid <NUM> is drawn into pumping volume <NUM> from the upstream portion <NUM> of the tubing <NUM>.

In the depicted example, the expansion of the upstream portion <NUM> permits the flow of medical fluid <NUM> into the pumping volume <NUM>. Advantageously, and as described herein, the feeler pin <NUM> can extend through the plunger <NUM> to maintain contact with the tubing <NUM> during the filling phase to permit measurement of the pumping volume. In the depicted example, the force applied by the biasing member <NUM> can be sufficient to maintain contact with the tubing <NUM> while allowing for the pumping volume <NUM> to be filled.

During operation, the compression of the pumping volume <NUM> expels or otherwise administers fluid from the pumping volume <NUM> to a downstream location. As described herein, the plunger biasing member <NUM> force the plunger <NUM> to compress the pumping volume <NUM> to a compressed or reduced state.

In the depicted example, the upstream valve <NUM> is actuated, moved downward, or otherwise engaged to compress the tubing walls <NUM> of the tubing <NUM> at the upstream portion <NUM> to occlude flow through the upstream portion <NUM> of the tubing <NUM>. During the compression of the pumping volume <NUM>, medical fluid is forced from the pumping volume <NUM> to a downstream location through the downstream portion <NUM> of the tubing <NUM>.

In the depicted example, the expansion of the downstream portion <NUM> permits the flow of medical fluid <NUM> out of the pumping volume <NUM>. The amount of medical fluid <NUM> administered from the pumping volume <NUM> during the delivery phase can be determined by the timing and sequence of the plunger <NUM>, the downstream valve <NUM> and the mechanical properties of the tubing <NUM>.

Advantageously, and as described herein, the feeler pin <NUM> can maintain contact with the tubing <NUM> during the delivery phase to permit measurement of the pumping volume during the entire cycle, providing more information to a clinician without interrupting fluid delivery.

Claim 1:
A peristaltic pump (<NUM>) comprising: a plunger (<NUM>) movable to selectively engage a pumping volume (<NUM>) of a tubing segment (<NUM>); an upper valve (<NUM>) movable to selectively engage an upstream portion (<NUM>) of the tubing segment; a lower valve (<NUM>) movable to selectively engage a downstream portion (<NUM>) of the tubing segment;
characterized by:
a camshaft (<NUM>) comprising a first plunger cam lobe (154a) and a second plunger cam lobe (154b), wherein the first plunger cam lobe is configured to move the plunger between an engaged position in contact with the pumping volume and a disengaged position spaced apart from the pumping volume, the second plunger cam lobe is configured to move the plunger between an expansion position to draw fluid flow into the pumping volume and a contraction position to conduct fluid flow from the pumping volume, and the first plunger cam lobe and the second plunger cam lobe are out of phase to permit the first plunger cam lobe to move the plunger to the engaged position and the second plunger cam lobe away from the contraction position during a measurement phase;
a first rocker (111a), wherein the first plunger cam lobe is configured to actuate the first rocker;
a second rocker (111b), wherein the second plunger cam lobe is configured to actuate the second rocker;
a first biasing member (164a) coupled to the first rocker, the first biasing member configured to urge the plunger toward the tubing segment to maintain contact with the tubing segment in the engaged position;
a second biasing member (164b) coupled to the second rocker, the second biasing member configured to urge the plunger toward the tubing segment to contract the pumping volume in the contraction position.