Air detection method for pumps by volume measurement

Abstract

A method for detecting air in a pump is described herein. In one embodiment, a pump for detecting air comprises a plunger, a plunger air detection module, a camshaft, and a first biasing member. The plunger is movable to selectively engage with a tube segment containing fluid. The plunger air detection module is located within the plunger. The camshaft is configured to move the plunger between an engaged position in contact with the tube segment and an unengaged position separated from the tube segment. In the engaged position, the first biasing member is configured to press the plunger toward the tube segment and maintain contact with the tube segment.

Description

Technical Field

[0001] The present invention generally relates to a method for detecting air in a pump, and more particularly to a method for detecting air in a peristaltic pump.

Background Art

[0002] Patients in hospitals are often infused with drugs or medical fluids (e.g., saline or liquid drugs) using an intravenous (IV) pump. In some applications, the IV pump uses a peristaltic operation of a portion of the tube of the IV set to generate a flow of medical fluid to the patient. Also, in some applications, volume measurements can be made to detect the flow rate of the fluid passing through the pump.

[0003] Particularly in infusion therapy, the accuracy of the flow rate is extremely important for clinicians and patients. New technologies are being developed to input information regarding the infusion rate into the pump control unit in real time. However, existing methods used to measure the infusion rate often assume that there is no air in the subsystem performing the measurement. This assumption is not always appropriate because it is common for air bubbles to be present in the set. If air bubbles enter the volume measurement subsystem within the pump, the measurement results can become inaccurate. This can cause the pump control to incorrectly adjust the flow rate, resulting in risks such as over-infusion, under-infusion, air embolism that occurs when the bag is empty, thrombosis that occurs when the bag is empty and the keep-vein-open (KVO) mode is not initiated, etc., being exposed to the patient.

Summary of the Invention

[0004] The subject matter of this disclosure relates to a peristaltic pump capable of detecting the presence of air present in and extending through a tube segment. In one embodiment, the pump for detecting air comprises a plunger movable to selectively engage with a tube segment containing fluid; a camshaft configured to move the plunger between an engaged position in contact with the tube segment and an unengaged position separated from the tube segment; and a first biasing member configured to press the plunger toward the tube segment and maintain contact with the tube segment in the engaged position, wherein the plunger comprises a plunger air detection module.

[0005] In one embodiment, the pump includes a backer configured to engage with a tube segment in an engaged and disengaged position. The backer includes a channel configured to prevent movement of the tube segment relative to the pump, the channel extending longitudinally along the backer. In one embodiment, the channel is defined by a forward wedge and a rear barrier extending longitudinally along the backer, and the backer also includes a notch extending longitudinally along its length. In one embodiment, the notch is configured to receive a backer air detection module. In one embodiment, the backer air detection module is parallel to a plunger air detection module, and the plunger air detection module is configured to transmit a signal when the plunger is in the engaged position, and the backer air detection module is configured to receive that signal.

[0006] In one embodiment, the plunger air detection module includes a plurality of elements, and the plunger air detection module includes elements of a piezoelectric array. In one embodiment, the pump has a slot defined in the plunger, and the plunger air detection module is located in the slot. In one embodiment, the plunger does not deform the tube segment in the engagement position.

[0007] In one embodiment, the method of the present disclosure includes arranging a tube segment in a pump, the tube segment containing a fluid flowing through it, pressing a plunger against the tube segment as the fluid flows through it, maintaining contact with the tube segment as the fluid flows through it, and transmitting a signal from a plunger air detection module of the plunger through the tube segment. In one embodiment, the method includes receiving a signal by a backer air detection module of a backer. In one embodiment, the method includes moving a plunger by a camshaft to increase or decrease the cross-section of the tube segment to adjust the flow rate of fluid passing through the tube segment. In one embodiment, the method includes moving a plunger by a camshaft to decrease the cross-section of the tube segment and block the flow of fluid passing through the tube segment. In one embodiment, the backer air detection module is parallel to the plunger air detection module when the plunger is pressed toward the tube segment to maintain contact with it. In one embodiment, the tube segment is not deformed when the plunger is pressed toward the tube segment to maintain contact with it.

[0008] Those skilled in the art will readily understand the various configurations of this technology from the disclosures of this invention. Although the various configurations of this technology are shown and described by example, as those skilled in the art will understand, this technology can take on other different configurations, and some of its details can be modified in various ways, but none of these will depart from the scope of this technology. Therefore, the "Summary of the Invention," "Drawings," and "Modes for Carrying Out the Invention" are illustrative and should not be interpreted as limiting.

[0009] The drawings accompanying this specification are provided to enhance the understanding of the invention, are incorporated into this specification, and constitute part thereof, illustrating the disclosed embodiments and illustrating the principles of the disclosed embodiments together with the description. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows a patient receiving medical fluid infusion using an IV pump. [Figure 2A] This is a perspective view of a peristaltic pump relating to various aspects of this disclosure. [Figure 2B] Figure 2A is a simplified diagram of the peristaltic pump. [Figure 3] Figure 2A is an exploded view of the components of the peristaltic pump. [Figure 4] Figure 2A is an exploded view of the plunger and backer of the peristaltic pump. [Figure 5] This is a perspective view of a peristaltic pump relating to various aspects of this disclosure. [Modes for carrying out the invention]

[0011] The detailed descriptions provided below in this specification are intended to illustrate various configurations of the Art and do not represent the only configurations in which the Art can be carried out. The "Modes for Carrying Out the Invention" include certain details to fully understand the Art. However, it will be apparent to those skilled in the art that the Art can be carried out without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring the concepts of the Art. Similar components are denoted by the same reference numerals for ease of understanding. Reference numerals may be subscripted to indicate specific examples of common elements, but are generally referred to by the unsubscripted numerals.

[0012] The following description relates to the delivery of medical fluids using the disclosed peristaltic pump, but this description is intended to illustrate an example of use and does not limit the scope of the claims. Various embodiments of the disclosed peristaltic pump can be used in any application where it is desirable to control and deliver the flow of a fluid.

[0013] Figure 1 shows a patient 5 receiving medical fluid infusion using an IV pump 30. In the illustrated example, the IV pump 30 delivers medical fluid from a fluid container 36 to patient 5. The fluid container 36 is suspended above or above the patient's head and connected to an IV pump module 34 via an IV set 20, which in turn connects to patient 5. In some embodiments, the IV pump 30 includes a control unit 32 and a pumping module 34. Suitable IV pump configurations and systems are described, for example, in U.S. Patent Application No. 17 / 586,619, the entire disclosure of which is incorporated herein by reference.

[0014] The pumping module 34 may be equipped with a peristaltic pump for delivering medical fluid from the fluid container 36 to the patient 5. It may be desirable to monitor the volume delivered by the peristaltic pump while it is operating. In some applications, the peristaltic pump may include a measurement phase between a refill phase and a delivery phase.

[0015] The peristaltic pumps of this disclosure may incorporate various measuring mechanisms to enable not only detection of the presence of air but also monitoring of the volume being pumped by the peristaltic pump. The peristaltic pumps of this disclosure may include a tactile mechanism, biasing members having varying levels of force, and / or a split plunger. By utilizing the measuring mechanisms disclosed herein, the peristaltic pump can perform monitoring without providing a dedicated measuring phase and / or without generating high internal pressure.

[0016] The peristaltic pump of this disclosure solves several problems found in relation to specific air detection methods used in IV sets. One problem in specific air detection methods is the active adjustment of the fluid volume resulting from air detection. Therefore, simply adding an inline air sensor is not sufficient. An inline air sensor may only alert or notify the patient or clinician if the amount of air passing through exceeds a threshold. Furthermore, an inline air sensor assumes that all bubbles move downstream. However, in reality, bubbles may stagnate along the way or backflow upward, activating the sensor multiple times. Since the fluid volume passing through the peristaltic pump of this disclosure flows downstream and its volume is measured, it is advantageous to provide an inline air detection function to the fluid volume measurement system and correct the measured volume by directly measuring the amount of air passing through.

[0017] An example of a peristaltic pump that enables fluid volume measurement and inline air detection is described below.

[0018] Figure 2A is a perspective view of a peristaltic pump 100 according to various embodiments of the present disclosure. Figure 2B is a simplified diagram of the peristaltic pump 100 of Figure 2A. In the illustrated examples, the peristaltic pump 100 can regulate the flow of medical fluid to the patient by peristaltically deforming a tube (not shown). In some embodiments, the upstream portion of the tube 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 tube is in fluid communication with an IV tube connected to the patient. In some embodiments, the peristaltic pump 100 operates repeatedly and periodically between a filling phase and a delivery phase to deliver fluid to the patient. As described herein, the peristaltic pump 100 can perform volume measurement and air detection without requiring a dedicated measurement phase.

[0019] In the illustrated example, the peristaltic pump 100 includes a plunger 110, an upstream shut-off valve or valve 120, and a downstream shut-off valve or valve 130, all of which contact and deform a tube and are configured to send fluid from a fluid source to a patient. In some embodiments, the plunger 110, the upstream valve 120, and the downstream valve 130 may move in a coordinated series of steps to pump fluid through the tube. The tube may be formed from a material having mechanical elasticity. When the plunger 110, the upstream valve 120, and / or the downstream valve 130 contact and deform the tube, the tube may be supported by a backing 180.

[0020] As described herein, the plunger 110, the upstream valve 120, and / or the downstream valve 130 can be moved by one or more actuators. The movement of the actuators controlling the plunger 110, the upstream valve 120, and / or the downstream valve 130 can be coordinated or sequenced. In the illustrated example, the movement of the plunger 110, the upstream valve 120, and / or the downstream valve 130 is periodic.

[0021] Figure 3 is an exploded view of the components of the peristaltic pump 100 of Figure 2A. Referring to Figures 2A - 3, the peristaltic pump l00 may include a camshaft 150 for operating the plunger 110, the upstream valve 120, and / or the downstream valve 130. In the illustrated example, the camshaft 150 includes one or more cam lobes such as a plunger cam lobe 154, an upstream valve cam lobe 152, and / or a downstream valve cam lobe 156.

[0022] As described herein, the geometry of each cam lobe can be shaped or deformed to enable the desired operation or movement of the plunger 110, the upstream valve 120, and / or the downstream valve 130. For example, the portion of the cam lobe having a larger radius can open or lift the plunger 110, the upstream valve 120, and / or the downstream valve 130 away from the tube and / or the backer 180, while the portion of the cam lobe having a smaller radius can bring the plunger 110, the upstream valve 120, and / or the downstream valve 130 closer to or press them against the tube and / or the backer.

[0023] In some embodiments, the cam lobes of the camshaft 150 actuate one or more rockers to control the plunger 110, the upstream valve 120, and / or the downstream valve 130. As will be appreciated, the geometry of the rockers described herein can be configured to provide a desired operating ratio between the movement of the plunger 110, the upstream valve 120, and / or the downstream valve 130 and the geometry of the plunger-cam lobe 154, the upstream valve-cam lobe 152, and / or the downstream valve-cam lobe 156. As described herein, certain rockers, such as the second plunger-valve rocker 111b, can move independently or may not be actuated directly by the camshaft 150. The first plunger-valve rocker 111a, the second plunger-valve rocker 111b, the upstream valve rocker 121, and / or the downstream valve rocker 131 can each rotate or pivot about the pivot axis 170.

[0024] In the illustrated example, a biasing member, such as a spring, may press the plunger 110, the upstream valve 120, and / or the downstream valve 130 toward the tube and / or backer 180. In some embodiments, the biasing member acts on a rocker, which may press the plunger 110, the upstream valve 120, and / or the downstream valve 130 toward the tube and / or backer 180. During operation, the actuation of the plunger 110, the upstream valve 120, and / or the downstream valve 130 by the camshaft may overcome the biasing force applied by the biasing member, lifting or operating the plunger 110, the upstream valve 120, and / or the downstream valve 130.

[0025] Furthermore, the arrangement or phasing of the cam lobes relative to the camshaft 150 can be modified to provide a desired series of actions or movements of the plunger 110, the upstream valve 120, and / or the downstream valve 130 as the camshaft 150 rotates. For example, the plunger cam lobe 154, the upstream valve cam lobe 152, and / or the downstream valve cam lobe 156 may each have a cam profile and / or relative arrangement that excludes or does not include a dedicated measuring phase, which is the phase in which the plunger 110 acts relative to the pumping chamber of the tube closed by the upstream valve 120 and the downstream valve 130.

[0026] In the illustrated example, the peristaltic pump 100 comprises a separate rocker having a first plunger valve rocker 111a directly connected to the plunger 110 and a second plunger valve rocker 111b configured to act on the first plunger valve rocker 111a. In some embodiments, the first plunger valve rocker 111a is spaced apart from, unconnected to, or unaligned with, or not directly actuated by, the plunger cam lobe 154. As can be understood, the first plunger valve rocker 111a, and by extension the plunger 110, can be moved or actuated independently of the action of the plunger cam lobe 154.

[0027] In the illustrated example, the first plunger biasing member 164a acts on the first plunger valve rocker 111a to press the plunger 110 toward the tube and / or backer 180. As understood, the biasing force that the first plunger biasing member 164a applies to the first plunger valve rocker 111a and plunger 110 is a constant or continuous force independent of the rotation of the camshaft 150. During operation, the arrangement of the first plunger valve rocker 111a and the first plunger biasing member 164a allows the plunger 110 to maintain contact with the tube. As understood, the force applied by the first plunger biasing member 164a may be large enough to allow the plunger 110 to maintain contact without damaging the tube.

[0028] In the illustrated example, the position of the plunger 110 can be used to determine the volume of fluid being pumped by the peristaltic pump 100. During operation, the height of the plunger 110 can be used to determine the height of the pumping chamber in the tube, from which the volume of fluid being pumped by the peristaltic pump 100 can be determined. Advantageously, the arrangement of the first plunger biasing member 164a and the first plunger valve rocker 111a allows the plunger 110 to measure volume without applying excessive force or requiring a dedicated measurement phase.

[0029] In the illustrated example, the second plunger valve rocker 111b is configured to be aligned, positioned, or actuated by the plunger cam lobe 154. During operation, a portion of the second plunger valve rocker 111b engages with or slides along the cam profile of the plunger cam lobe 154, so that the geometry of the cam profile can be translated into movement of the second plunger valve rocker 111b. In some embodiments, during certain operation (e.g., during the fluid delivery phase of operation), the second plunger valve rocker 111b engages with the first plunger valve rocker 111a, so that the plunger 110 moves relative to the tube in response to the actuation from the plunger cam lobe 154.

[0030] In the illustrated example, the second plunger biasing member 164b may act on the second plunger valve rocker 111b to press the second plunger valve rocker 111b toward the first plunger valve rocker 111a. During operation of a particular portion of the operation (e.g., during the fluid delivery phase of the operation), the second plunger biasing member 164b may engage the second plunger valve rocker 111b with the first plunger valve rocker 111a, pressing the plunger 110 toward the tube and / or backer 180. As understood, the actuation of the second plunger valve rocker 111b by the rotation of the plunger cam lobe 154 may overcome the biasing force and disengage the second plunger valve rocker 111b from the first plunger valve rocker 111a. Therefore, the biasing force applied to the first plunger valve rocker 111a and / or plunger 110 by the second plunger biasing member 164b can change in response to the operation of the second plunger valve rocker 111b due to the rotation of the plunger cam lobe 154. 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 100 to apply an additional force to the plunger during operation of a particular part of the operation (e.g., the fluid delivery phase), while allowing the first plunger biasing member 164a to maintain a sustained biasing force on the tube. In some embodiments, the force applied by the second plunger biasing member 164b is greater than the biasing force applied by the first plunger biasing member 164a. Optionally, the force applied by the second plunger biasing member 164b is large enough to enable fluid transfer. In some embodiments, the first plunger biasing member 164a and the second plunger biasing member 164b work together to provide sufficient force to enable fluid transfer.

[0031] In some embodiments, the upstream valve rocker 121 is connected to the upstream valve 120 and can move the upstream valve 120 in response to an action from the upstream valve cam lobe 152. During operation, a portion of the upstream valve rocker 121 engages with or slides along the cam profile of the upstream valve cam lobe 152, and the geometry of the cam profile can be translated into the movement of the upstream valve 120 relative to the tube.

[0032] As shown in the figure, the upstream valve biasing member 162 acts on the upstream valve rocker 121, which can press the upstream valve 120 toward the tube and / or backer 180. As can be understood, the actuation of the upstream valve rocker 121 by the rotation of the upstream valve cam lobe 152 may overcome the biasing force and lift or actuate the upstream valve 120.

[0033] Similarly, the downstream valve rocker 131 is connected to the downstream valve 130 and can move the downstream valve 130 in response to the action from the downstream valve cam lobe 156. During operation, a portion of the downstream valve rocker 131 engages with or slides along the cam profile of the downstream valve cam lobe 156, and the geometry of the cam profile can be translated into the movement of the downstream valve 130 relative to the tube.

[0034] Similarly, the downstream valve biasing member 166 acts on the downstream valve rocker 131, which can press the downstream valve 130 toward the tube and / or backer 180. As understood, the actuation of the downstream valve rocker 131 by the rotation of the downstream valve cam lobe 156 may overcome the biasing force and lift or actuate the downstream valve 130.

[0035] Figure 4A shows the peristaltic pump 100 of Figure 2A in the filling phase according to various embodiments of the present disclosure. During operation, the tube 102 draws in the medical fluid 10 during the filling phase. As shown, the plunger 110 is pulled back or retracted from the compression portion of the tube 102, allowing the tube wall 104 to elastically expand the pumping chamber 107 to its original or expanded state.

[0036] In the illustrated example, fluid is drawn into the pumping chamber 107 by its expansion. Due to the mechanical elasticity of the tube 102, the tube wall 104 expands from a compressed state to an expanded state, expanding the pumping chamber 107. The amount of fluid that can be drawn into the pumping chamber 107 within a predetermined time can be determined by the speed at which the pumping chamber 107 returns from the compressed state to the expanded state.

[0037] As shown in the figure, during the expansion of the pumping chamber 107, the downstream portion 108 of the tube 102 is blocked, pinched, or otherwise occluded by the downstream valve 130 to prevent or limit the backflow or contamination of fluid back into the pumping chamber 107.

[0038] In the illustrated example, the downstream valve 130 is actuated and moves downward or engages, compressing the tube wall 104 of the tube 102 in the downstream portion 108 and blocking the flow through the downstream portion 108 of the tube 102. The downstream valve 130 may have an inclined engaging portion for contacting the tube 102. When engaged, the downstream valve 130 may prevent or restrict the flow or fluid passage from the downstream portion 108 to the pumping chamber 107.

[0039] During the expansion of the pumping chamber 107, the medical fluid 10 is drawn into the pumping chamber 107 from the upstream portion 106 of the tube 102. As shown in the figure, during the expansion of the pumping chamber 107, the upstream portion 106 of the tube 102 is not obstructed by the upstream valve 120, and as a result, the medical fluid 10 is allowed to flow into the pumping chamber 107. During operation, the upstream valve 120 is pulled back or retracted from the compressed portion of the tube 102, and as a result, the tube wall 104 is allowed to elastically expand the upstream portion 106 to its original or expanded state.

[0040] In the illustrated example, the expansion of the upstream section 106 allows the medical fluid 10 to flow into the pumping chamber 107. Due to the mechanical elasticity of the tube 102, the tube wall 104 expands from a compressed state to an expanded state, increasing the cross-sectional shape or flow area of ​​the upstream section 106. The amount of medical fluid 10 drawn into the pumping chamber 107 during the filling phase can be determined by the timing and sequence of operations of the plunger 110, the upstream valve 120, the viscosity of the medical fluid 10, and the mechanical properties of the tube 102.

[0041] As described herein, advantageously, the first plunger biasing member 164a maintains a constant or sustained force, allowing the plunger 110 to maintain contact with the tube 102 during the filling phase and enabling measurement of the volume being pumped. In the illustrated example, the force applied by the first plunger biasing member 164a may be sufficient to maintain contact with the tube 102 while enabling the filling of the pumping chamber 107.

[0042] Figure 4B shows the peristaltic pump 100 of Figure 2A in the fluid delivery phase according to various embodiments of the present disclosure. Figure 4C shows the peristaltic pump 100 of Figure 2A in the fluid delivery completion position according to various embodiments of the present disclosure. Referring to Figures 4B and 4C, the peristaltic pump 100 delivers medical fluid to a downstream position such as a patient through the downstream section 108. As shown, the plunger 110 is actuated, moves downward, or engages to compress the tube wall 104 of the tube 102, and compresses or contracts the pumping chamber 107.

[0043] During operation, compression of the pumping chamber 107 causes fluid to be discharged or delivered downstream from the pumping chamber 107. The delivery rate of the medical fluid can be controlled by the pressing force and speed of the plunger 110.

[0044] As described herein, the first plunger biasing member 164a and the second plunger biasing member 164b cooperate to press the plunger 110 and compress or contract the pumping chamber 107. In some embodiments, the second plunger biasing member 164b can press the plunger 110 and compress or contract the pumping chamber 107 without cooperation from the first plunger biasing member 164a.

[0045] During fluid delivery, the upstream portion 106 of the tube 102 is blocked, pinched, or otherwise occluded by the upstream valve 120 to prevent or limit the inflow of unwanted fluid into the pumping chamber 107, and further prevent or limit the backflow of fluid from the pumping chamber 107 to the medical container.

[0046] In the illustrated example, the upstream valve 120 is actuated and moves downward or engages, compressing the tube wall 104 of the tube 102 in the upstream portion 106 and blocking the flow through the upstream portion 106 of the tube 102. The upstream valve 120 may have an inclined engaging portion for contacting the tube 102. When engaged, the upstream valve 120 may prevent or restrict flow or fluid flow between the upstream portion 106 and the pumping chamber 107.

[0047] During compression of the pumping chamber 107, the medical fluid is pushed out of the pumping chamber 107 to a downstream position through the downstream portion 108 of the tube 102. As shown in the figure, during compression of the pumping chamber 107, the downstream portion 108 of the tube 102 is not obstructed by the downstream valve 130, allowing the medical fluid 10 to flow out of the tube 102. During operation, the downstream valve 130 is pulled back or retracted from the compressed portion of the tube 102, allowing the tube wall 104 to elastically expand the downstream portion 108 to its original or expanded state.

[0048] In the illustrated example, the expansion of the downstream section 108 allows the medical fluid 10 to flow out of the pumping chamber 107. Due to the mechanical elasticity of the tube 102, the tube wall 104 can expand from a compressed state to an expanded state, thereby expanding the cross-sectional shape or flow area of ​​the downstream section 108. The speed at which the downstream section 108 returns from a compressed state to an expanded state can limit the flow area or opening size from the pumping chamber 107. Therefore, the speed at which the downstream section 108 returns from a compressed state to an expanded state can limit or suppress the amount of fluid that can flow out of the pumping chamber 107 within a given time.

[0049] The amount of medical fluid 10 delivered from the pumping chamber 107 during the fluid delivery phase can be determined by the timing and sequence of operations of the plunger 110, the downstream valve 130, and the mechanical properties of the tube 102.

[0050] During operation, the arrangement of the first plunger valve rocker 111a, the first plunger cam lobe 154a, and the first plunger biasing member 164a may allow the plunger 110 to contact the tube during the measurement phase without pumping fluid from the pumping chamber or damaging the tube. In some embodiments, the first plunger valve rocker 111a, the first plunger cam lobe 154a, and the first plunger biasing member 164a may allow the plunger 110 to be in constant contact with the tube. The first plunger biasing member 164a applies force to the plunger 110 so that the plunger 110 can contact the tube 102 to determine the height of the tube 102, the height of the pumping chamber 107, and / or the presence of air. In the illustrated example, the force applied by the first plunger biasing member 164a may be sufficient to maintain contact with the tube 102 without creating excessive pressure in the pumping chamber.

[0051] During operation, tube 102 (shown in Figure 1) draws in medical fluid 10 during the filling phase. The plunger 110 is pulled back or retracted from the compressed portion of tube 102, allowing the tube wall 104 to elastically expand the pumping chamber 107 to its original or expanded state. Due to the mechanical elasticity of tube 102, the tube wall 104 is able to expand from the compressed state to the expanded state, thereby expanding the pumping chamber 107. The speed at which the pumping chamber 107 returns from the compressed state to the expanded state can determine the amount of fluid that can be drawn into the pumping chamber 107 within a given time.

[0052] During the expansion of the pumping chamber 107, the downstream portion 108 of the tube 102 may be blocked, pinched, or occluded by the downstream valve 130 to prevent or limit backflow, air, or fluid contamination into the pumping chamber 107. The downstream valve 130 may be actuated, moved downward, or engaged to compress the tube wall 104 of the tube 102 in the downstream portion 108, thereby blocking the flow through the downstream portion 108 of the tube 102. The downstream valve 130 may have an inclined engaging portion for contact with the tube 102. When engaged, the downstream valve 130 may prevent or limit flow or fluid communication from the downstream portion 108 to the pumping chamber 107.

[0053] During the expansion of the pumping chamber 107, the medical fluid 10 is drawn into the pumping chamber 107 from the upstream portion 106 of the tube 102. As shown in the figure, during the expansion of the pumping chamber 107, the upstream portion 106 of the tube 102 is not obstructed by the upstream valve 120, and as a result, the medical fluid 10 is allowed to flow into the pumping chamber 107. During operation, the upstream valve 120 is pulled back or retracted from the compressed portion of the tube 102, allowing the tube wall 104 to elastically expand the upstream portion 106 to its original or expanded state.

[0054] The expansion of the upstream section 106 may allow the medical fluid 10 to flow into the pumping chamber 107. Due to the mechanical elasticity of the tube 102, the tube wall 104 can expand from a compressed state to an expanded state, expanding the cross-sectional shape or flow area of ​​the upstream section 106. The amount of medical fluid 10 drawn into the pumping chamber 107 during the filling phase can be determined by the timing and sequence of operations of the plunger 110, the upstream valve 120, the viscosity of the medical fluid 10, and the mechanical properties of the tube 102. Advantageously, and as described herein, the first plunger biasing member 164a may maintain a constant or sustained force, allowing the plunger 110 to maintain contact with the tube 102 and measure the volume being pumped during the filling phase. In the illustrated example, the force applied by the first plunger biasing member 164a may be sufficient to maintain contact with the tube 102 while allowing the pumping chamber 107 to fill.

[0055] Figure 4 is an exploded view of the plunger 110 and backer 180. As shown, the plunger 110 may be equipped with a plunger air detection module 410, and the backer 180 may be equipped with a backer air detection module 420. The air detection modules 410 and 420 are located along the longitudinal axis L of the plunger 110 and backer 180, respectively. P , L B The air detection modules 410 and 420 may extend along the length of the plunger 110 and backer 180, respectively. The air detection modules 410 and 420 comprise multiple elements, each element performing in-line air measurement. In one embodiment, the air detection modules 410 and 420 may comprise a single element. The air detection module 410 may transmit a signal, and the air detection module 420 may receive that signal. In one embodiment, the air detection module 420 may transmit a signal, and the air detection module 410 may receive that signal. The air detection modules 410 and 420 may generally be arranged parallel to each other during measurement, particularly in the engagement position, when the plunger 110 is close to the backer 180.

[0056] The air detection modules 410, 420 may be piezoelectric arrays. As shown in Figure 4, the plunger 110 may have a slot or notch having a shape and dimensions for receiving the air detection module 410. The backer 180 may also have a slot or notch for receiving the air detection module 410. The piezoelectric array may comprise one or more elements that make up the air detection modules 410, 420. Each element of the piezoelectric array may be square. In one embodiment, each element of the piezoelectric array may be rectangular or other polygonal. In one embodiment, each element may be circular. To prevent the tube segment from moving relative to the pump 100, a channel 182 may be defined around the slot or notch of the backer 180. The channel 182 may comprise a forward wedge 184 and a rear barrier 186 extending from the backer 180. The forward wedge 184 has an angle to press the tube segment toward the rear barrier 186 when the tube segment is positioned inside it. Multiple front wedges 184 are aligned along the longitudinal axis L B The rear barrier 186 may substantially extend along the length of the backer 180. The rear barrier 186 has generally flat characteristics that extend from the backer 180. The rear barrier 186 is along the longitudinal axis L B It can substantially extend along the length of the backer 180.

[0057] Each element of the piezoelectric array may be approximately 4 mm wide x 4 mm. Each element of the piezoelectric array may be approximately 2 mm wide x 2 mm. Each element of the piezoelectric array may be approximately 2.5 mm wide x 2.5 mm. Each element of the piezoelectric array may be approximately 3 mm wide x 3 mm. Each element of the piezoelectric array may be approximately 3.5 mm wide x 3.5 mm. Each element of the piezoelectric array may be approximately 4.5 mm wide x 4.5 mm. Each element of the piezoelectric array may be approximately 5 mm wide x 5 mm. Each element of the piezoelectric array may be approximately 5.5 mm wide x 5.5 mm. Each element of the piezoelectric array may be approximately 6 mm wide x 6 mm.

[0058] Each element of the piezoelectric array may be approximately 0.86 mm thick. Each element of the piezoelectric array may be approximately 0.8 mm thick. Each element of the piezoelectric array may be approximately 0.81 mm thick. Each element of the piezoelectric array may be approximately 0.82 mm thick. Each element of the piezoelectric array may be approximately 0.83 mm thick. Each element of the piezoelectric array may be approximately 0.84 mm thick. Each element of the piezoelectric array may be approximately 0.85 mm thick. Each element of the piezoelectric array may be approximately 0.87 mm thick. Each element of the piezoelectric array may be approximately 0.88 mm thick. Each element of the piezoelectric array may be approximately 0.89 mm thick. Each element of the piezoelectric array may be approximately 0.9 mm thick. Each element of the piezoelectric array may be approximately 0.91 mm thick.

[0059] Figure 5 shows one embodiment of air detection modules 410 and 420 connected to plunger 110 and backer 180, respectively. In this example, air detection module 410 may be a transmitter and air detection module 420 may be a receiver. In one embodiment, air detection module 420 may be a transmitter and air detection module 410 may be a receiver. Housings (not shown) may be provided to cover the air detection modules 410 and 420 to protect them from external forces and foreign objects. Three air detection modules 410 and 420 may be arranged on plunger 110 and backer 180, respectively. In one embodiment, one air detection module 410 and 420 may be arranged on plunger 110 and backer 180, respectively. Air detection modules 410 and 420 may be cylindrical in shape. Air detection modules 410 and 420 may have the same elements as the elements that make up the piezoelectric array shown in Figure 4.

[0060] The delivery rate of the medical fluid can be controlled by the force and movement speed of the plunger 110. If air is detected in the tube, the rate of fluid volume passing through the pump can be controlled to ensure safe infusion to the patient.

[0061] This disclosure is provided to enable those skilled in the art to implement the various embodiments described herein. While this disclosure provides various examples of the art, the art is not limited to these examples. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may also apply to other embodiments.

[0062] When referring to an element in the singular form, unless otherwise specified, it means "one or more" and not "the only one." Unless otherwise specified, the word "some" refers to "one or more." Masculine pronouns (e.g., "his") include feminine and neuter forms (e.g., "her" and "its"), and vice versa. Headings and subheadings, where present, are for convenience only and do not limit the invention.

[0063] The term "exemplary" is used to mean "functioning as an example or illustration." Embodiments or designs described as "exemplary" in this specification should not be construed as necessarily superior or preferable to other embodiments or designs. In some embodiments, various alternative configurations and operations described herein may be considered at least equivalent.

[0064] The term "aspect" does not mean that the aspect is essential to the Art or that it applies to all configurations of the Art. Disclosure relating to an aspect may apply to all configurations or to only one or more configurations. An aspect may provide one or more examples. The term "aspect" may refer to one or more aspects, and vice versa. Similarly, the term "embodiment" does not mean that such an embodiment is essential to the Art or that it applies to all configurations of the Art. Disclosure relating to an embodiment may apply to all embodiments or to only one or more embodiments. An embodiment may provide one or more examples, and the term "embodiment" may refer to one or more embodiments, and vice versa. The term "configuration" also does not mean that the configuration is essential to the Art or that it applies to all configurations. Disclosure relating to a configuration may apply to all configurations or to only one or more configurations. The term "composition" may provide one or more examples, and the phrase "composition" may refer to one or more compositions, and vice versa.

[0065] In some embodiments, unless otherwise specified, all measurements, numerical values, evaluation values, locations, quantities, sizes, dimensions, and other specifications described herein (including subsequent claims) are approximate values ​​rather than exact values. In some embodiments, they are intended to have a reasonable range of variation that is consistent with the function in which they relate and the range generally accepted in the art.

[0066] In some embodiments, terms such as "coupled" may mean directly connected. In other embodiments, terms such as "coupled" may mean indirectly connected.

[0067] Where terms such as "top," "bottom," "front," and "rear" are used in this specification, they should be understood to refer to an arbitrary reference frame, not a standard based on the normal direction of gravity. Therefore, the top, bottom, front, and back may extend upward, downward, obliquely, or horizontally within the reference frame of gravity.

[0068] Various elements may be arranged in various ways (for example, in different orders or in different ways), but not all of these will deviate from the scope of this technology. All structural and functional equivalents of elements in various forms described throughout this specification, whether known to those skilled in the art or known later, are expressly incorporated by reference and intended to be included by the claims. Furthermore, nothing disclosed herein, whether expressly stated in the claims or not, is intended to be public property. The elements of the claims should not be construed under Section 112, Section 6 of the U.S. Patent Act unless the phrase "means for" or, in a method claim, the phrase "step for". Furthermore, terms such as "include" and "have" are intended to be used in a comprehensive sense, similar to the transition word "comprise" in the claims.

[0069] The “Title of the Invention,” “Background Art,” “Summary of the Invention,” “Brief Description of the Drawings,” and “Abstract” of this Disclosure are incorporated herein by reference and are provided as illustrative descriptions, not as restrictive descriptions of the disclosure. They are submitted with the understanding that they are not intended to limit the scope or meaning of the claims. Furthermore, in the “Modes for Carrying Out the Invention,” illustrative embodiments are presented and various features are combined in various embodiments for the purpose of conciseness of the disclosure; however, this method of description is not intended to indicate that the invention described in each claim requires more features than those explicitly described. Rather, as the following claims show, the subject matter of the invention resides in a part of, and does not necessarily depend on, all features of, a single disclosed configuration or operation. The following claims are incorporated herein by reference as independent inventive features.

[0070] The claims are not intended to be limited to the embodiments described herein, but should be interpreted in the broadest sense to encompass all legal equivalents thereof, to the extent consistent with the language of the claims. However, no claim is intended, nor should it be interpreted, to encompass matters that do not meet the requirements of Section 101, 102, or 103 of the U.S. Patent Act.

Claims

1. A pump for detecting air, A plunger that is movable to selectively engage with a fluid-containing tube segment, A plunger air detection module is placed inside the plunger, A camshaft configured to move the plunger between an engaged position in contact with the tube segment and an unengaged position separated from the tube segment, A first biasing member configured to press the plunger toward the tube segment and maintain contact with the tube segment at the engagement position, A pump equipped with the following features.

2. The pump according to claim 1, further comprising a backer configured to engage with the tube segment in the engagement position and the non-engagement position.

3. The pump according to claim 2, wherein the backer comprises a channel configured to prevent movement of the tube segment relative to the pump.

4. The pump according to claim 3, wherein the channel extends in the longitudinal direction of the backer.

5. The pump according to claim 4, wherein the channel is defined by a forward wedge and a rear barrier extending along the longitudinal direction of the backer.

6. The pump according to claim 2, wherein the backer has a notch that extends along the longitudinal direction.

7. The pump according to claim 6, wherein the notch is configured to receive a backer air detection module.

8. The pump according to claim 7, wherein the backer air detection module is parallel to the plunger air detection module.

9. The pump according to claim 8, wherein the plunger air detection module is configured to transmit a signal when the plunger is in the engagement position, and the backer air detection module is configured to receive the signal.

10. The pump according to claim 1, wherein the plunger air detection module includes a plurality of elements.

11. The pump according to claim 10, wherein the plunger air detection module includes elements of a piezoelectric array.

12. The pump according to claim 1, further comprising a slot defined within the plunger.

13. The pump according to claim 12, wherein the plunger air detection module is located within the slot.

14. The pump according to claim 1, wherein the plunger does not deform the tube segment at the engagement position.

15. A step providing a tube segment within a pump, wherein the tube segment contains a fluid flowing therethrough, The steps include pressing the plunger toward the tube segment and maintaining contact with the tube segment as the fluid flows through the tube segment, The steps include: transmitting a signal from the plunger air detection module of the plunger via the tube segment; A method that includes this.

16. The method according to claim 15, further comprising the step of receiving the signal with a backer air detection module of the backer.

17. The method according to claim 16, further comprising the step of moving the plunger with a camshaft to increase or decrease the cross-section of the tube segment to adjust the flow rate of the fluid through the tube segment.

18. The method according to claim 16, further comprising the step of moving the plunger with a camshaft to reduce the cross-section of the tube segment and prevent fluid flow through the tube segment.

19. The method according to claim 16, wherein the backer air detection module is parallel to the plunger air detection module when the plunger is pressed toward the tube segment to maintain contact with the tube segment.

20. The method according to claim 15, wherein the plunger does not deform the tube segment when the plunger is pressed toward the tube segment to maintain contact with the tube segment.

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