Patent Description:
The necessity of manually loading a set into an IV pump is universal in the art. Generally, when a standard IV set is used, in addition to the rapid degradation of accuracy mentioned above, difficulty is encountered in correctly loading the set into those pumps presently in the art. The state of the art of loading technology as it relates to medical infusion pumps has progressed only to the state of enclosing the IV tube between a pumping device and a door or cover and adding progressively more elaborate sensors and alarms to assure that the tube is correctly loaded into the pump. Even so, loading errors may occur requiring great efforts on the part of hospital staffs to ensure that critical errors are minimized.

The state of the art in infusion pumps also includes the requirement of manually assuring that a free-flow condition of medicament does not occur when an IV set is installed or removed from a pump. Although hospital staffs exercise great care and diligence in their attempts to assure that free-flow conditions do not occur, a demonstrable need for additional precautions directed to the prevention of a free-flow condition has been a continuous concern of healthcare workers.

<CIT> discloses an infusion pump that includes a sliding clamp for closing and releasing an infusion tube; a pump body including a tube attachment portion to which the infusion tube is to be attached; and a door pivotably supported by the pump body so that the tube attachment portion is openable and closable by the door. The pump body also includes a clamp attachment portion into which the sliding clamp having the infusion tube set therein is to be inserted; and a release operator in the clamp attachment portion to transfer the sliding clamp from a closed mode to a released mode. The release operator is configured to be locked in response to opening the door, so that the release operator is inoperable for releasing, and to be unlocked in response to closing the door.

<CIT> discloses an infusion line clamp system that includes a clamp which is configured to attach to an infusion line and reversibly occlude the infusion line. The clamp is biased to occlude the infusion line except when acted upon by an externally applied opening force. The system also includes an infusion pump having a control system, a clamp receptacle configured to releasably secure the clamp to the infusion pump, and a clamp actuation mechanism that is configured to selectively actuate the clamp under command of the control system by selective application of an opening force to the clamp when the clamp is secured to the pump.

<CIT> discloses an infusion pump having a main body portion that includes a display area for displaying user interface information and at least one pump module that is removably secured to the main body portion and adapted to receive an IV tube. The pump module includes means for applying pumping action to the IV tube. The pump module further includes an auxiliary display area for displaying supplemental user interface information. A microprocessor is contained in the main body portion for generating user interface information on the display areas.

<CIT> discloses a syringe pump with an occlusion detection system for detecting an occlusion in a fluid line by determining if a relationship between force measurements departs from an expected relationship.

According to a first aspect of the present invention there is provided an infusion pump according to claim <NUM>. In one embodiment, the pump has a pumping body, which consists of a v-shaped groove extending longitudinally along a pump assembly and has associated therewith a fixed, and a moveable jaw and a plurality of valves located at either end of the v-shaped groove or shuttle.

In operation, an operator such as a nurse or patient would commence infusion of a medicament by inserting a standard IV set tube into a tube-loading orifice located on the front of the pump. Additionally, the operator would simultaneously insert a slide clamp, which is associated with the tube into an appropriate slide clamp orifice located upstream, i.e. more toward the fluid source, of the tube-loading orifice. The operator would then actuate a tube loading sequence to load the tube into a tubeway. In an example, a series of pawls and a moveable upper jaw would serve to seize the tube and draw it into a tubeway, part of which is comprised of the v-shaped groove and valves. As the loading cycle progresses, the jaws and pawls close about the tube capturing the tube within the tubeway. Sequentially as the valves close to occlude the tube, the slide clamp would be moved to a position such that the slide clamp would no longer occlude the tube. Upon receipt of appropriate signals from associated electronics which would determine the pumping speed, allowable volume of air, temperature and pressure, the pump is actuated wherein fluid is drawn from the fluid source and expelled from the pump in a constant and metered amount.

Should the tube be misloaded into the tubeway or the tube-loading orifice, appropriate sensors would determine the existence of such a state and effect an alarm directed thereto. At the end of the infusion, actuation by an operator would serve to automatically close the slide clamp and release the tube from the pump.

The pump comprehends a variety of sensors directed to improve the safety of the infusion of medicament and which provide information on the state of the fluid passing through the pump. For example, the sensors provide information regarding the state of various mechanical subassemblies within the pump itself such as a positional location of the shuttle or v-shaped slot aforementioned, valve operation, slide clamp location, and misload detection.

The sensors relating to the state of the fluid being passed through the pump have themselves been improved with regard to accuracy. This has been accomplished by the development of a method of making contact between the sensor and the tube such that the contact is normal to the tube and the tube is placed in contact with the various sensors in such a way that there is neither a volumetric nor a stress gradient across the tube.

The infusion pump of the present invention includes, inter alia, a slide clamp ejection device that includes a solenoid configured to automatically eject the slide clamp based on inputs from sensors arranged on the infusion pump.

The sensors include a first Hall effect sensor configured to detect when the door is positioned in the closed state, an optical sensor such as an optical IR sensor configured to detect when the door is latched while positioned in the closed state and a pressure sensor configured to detect the presence of the tube at a load point along the tube channel.

In a first embodiment of the infusion pump of the first aspect of the present invention, the sensors also include a second Hall effect sensor configured to detect that a valve is closed to place the tube in an occluded state.

In a second embodiment of the infusion pump of the first aspect of the present invention, which may also be used in combination with the first embodiment, the infusion pump is configured to initiate an infusion after receiving a confirmation that at least one of the slide clamp is in an ejected state and the door is in a closed state.

In a third embodiment of the infusion pump of the first aspect of the present invention, which may also be used in combination with the first or the second embodiment, the infusion pump includes a sensor that detects the presence of the slide clamp within the channel.

In an fourth embodiment of the infusion pump of the first aspect of the present invention, which may also be used in combination with any one or more of the first to third embodiments, the infusion pump further includes a tube loading guidance system, wherein the tube loading guidance system includes one or more visual cues configured to provide guidance to a user during tube loading.

In a fifth embodiment of the infusion pump of the first aspect of the present invention, which may be used in combination with the fourth embodiment, the visual cues include a first light-emitting diode, a second light emitting diode, and a display. The first and second light emitting diodes are configured to indicate whether a tube is properly or improperly loaded at respective load points on the infusion pump.

In a sixth embodiment of the infusion pump of the first aspect of the present invention, which may also be used in combination with any one or more of the first to fifth embodiments, the infusion pump further includes an occlusion sensor. The occlusion sensor is configured to determine if an infusion line connected to the infusion pump is blocked.

In a seventh embodiment of the infusion pump of the first aspect of the present invention, which may be used in combination with the sixth embodiment, the occlusion sensor determines if an infusion line is blocked by calculating a slope of a force curve, a slope of a pressure curve, a comparison to a baseline force measurement, a comparison to a baseline pressure measurement, or an area under the force curve.

In an eighth embodiment of the infusion pump of the first aspect of the present invention, which may also be used in combination with any one or more of the first to seventh embodiments, the infusion pump further includes an accelerometer. The accelerometer is configured to detect an occlusion and/or whether the infusion pump experienced an external impact.

In a ninth embodiment of the infusion pump of the first aspect of the present invention, which may also be used in combination with any one or more of the first to eighth embodiments, the infusion pump is positioned in a rack with at least one other infusion pump or syringe pump.

In one particular embodiment, a tube loading guidance system for positioning a tube within an infusion pump housing includes a first visual cue, a second visual cue, and a third visual cue. The first visual cue is configured to indicate both proper and improper loading of a slide clamp in the infusion pump. The second visual cue is configured to indicate both proper and improper loading of the tube at a first load point in the infusion pump. Additionally, the third visual cue is configured to indicate both proper and improper loading of the tube at a second load point in the infusion pump. The second visual cue and the third visual cue can include light emitting diodes. The light emitting diodes can indicate proper loading by illuminating in a first color. Additionally, the light emitting diodes indicate improper loading by illuminating in a second color. The second visual cue can be illuminated based on an output from a pressure sensor associated with the first load point. The third visual cue can be illuminated based on an output from a different pressure sensor associated with the second load point.

Also described herein but not claimed is a method of detecting an occlusion that includes monitoring a pressure measurement, comparing the pressure measurement to a threshold, and determining an occlusion exists within a tube of an infusion pump when the pressure measurement is greater than the threshold. The pressure measurement is based on a current Analogue to Digital Converter count, a baseline Analogue to Digital Converter count, and a slope of an Analogue to Digital Converter-pressure count plot. Additionally, the threshold is based on a selected occlusion detection mode. The selected occlusion detection mode can include one of a rapid occlusion detection mode and a non-rapid occlusion detection mode. The threshold may be lower for the rapid occlusion detection mode than the non-rapid occlusion detection mode.

Therefore, it is a primary object of the invention to provide for an infusion pump capable of delivering an accurate volume of medicament using a standard infusion set.

It is another object of the invention to provide an infusion pump capable of detecting proper IV tube loading.

It is another object of the invention to provide an infusion pump capable of providing IV tube loading guidance to a user.

It is a further object of the invention to provide automatically actuated slide clamp ejection based on various pump sensor input.

It is another object of the invention to provide occlusion detection for an infusion pump.

It is an additional object of the invention to provide drop detection for an infusion pump.

It is a further object of the invention to provide power management for an infusion pump loaded in a rack configuration.

Additional features and advantages of the disclosed infusion pump are described in, and will be apparent from, the following Detailed Description and the Figures. The features and advantages described herein are not all-inclusive and any particular embodiment does not have to have all of the advantages listed herein.

The below disclosure relates to an infusion pump <NUM>. Infusion pump <NUM> may employ a pump assembly and other features such as and not limited to those described in <CIT>; a volumetric infusion pump with automatic tube load described in <CIT>; a volumetric infusion pump described in <CIT>; a volumetric infusion pump described in <CIT>; a volumetric infusion pump described in <CIT>; a volumetric infusion pump described in <CIT>; and a peristaltic pump described in <CIT>. The above examples are non-limiting and the concepts disclosed herein could apply to other medical devices and/or infusion pumps such as a syringe pump.

Referring to <FIG>, <FIG>, an infusion pump <NUM> is used to deliver fluids (e.g., medications or nutrients) to a patient in predetermined quantities. The infusion pump <NUM> includes a housing <NUM>, a door <NUM> pivotally connected to the housing <NUM>, a display <NUM>, and a keypad <NUM>. The display <NUM> and keypad <NUM> are located on the door <NUM> along with beacon <NUM>. The display <NUM> and the keypad <NUM> are used to program the infusion pump <NUM>, and more specifically, a processor in the pump to set the fluid delivery amount, etc., which is later communicated to the pumping mechanism. It should be appreciated that in various other embodiments, one or more elements of the display <NUM> and the keypad <NUM> could be combined in central touch screen.

Beacon <NUM> may be used as an indicator beacon that emits light or sound to indicate operational states or status of pump <NUM>. For example, when the pump <NUM> is operating normally and infusing fluids, the beacon <NUM> may emit a solid green light. During a medium priority alarm, the beacon <NUM> may emit a flashing yellow light. Similarly, during a high priority alarm, the beacon may emit a flashing red light. The beacon <NUM> may emit other combinations of colors at various intervals (e.g., pulsing, blinking, solid light) or other audible alerts to indicate the operational state or status of pump <NUM>.

When the pump <NUM> is in use, fluids move through a tube loaded into the pump <NUM>. The tube <NUM> is loaded along the tube channel <NUM> on the pump <NUM>. Along the tube channel <NUM>, the tube passes through a slide clamp <NUM>, an ultrasonic air sensor <NUM>, an upstream pressure sensor 174a, an upstream valve 176a, the shuttle pumping region <NUM>, a downstream valve 176b, and a downstream pressure sensor 174b. Positioned on the door <NUM> are other tube engagement features, such as indentions 186a, 186b and tube guide <NUM>. The tube guide <NUM> is adapted to maintain the tube's position in the shuttle pumping region <NUM>.

As illustrated in <FIG>, the pressure sensors 174a, 174b have corresponding door structures (e.g., protrusions or setscrews) that ensure the tube <NUM> is sufficiently held against the respective sensor. For example, protrusions 184a and 184b correspond to pressure sensors 174a, 174b. Additionally, protrusion <NUM> corresponds to ultrasonic air sensor <NUM>. There may also be corresponding door indentions for each of the valves 176a, 176b. For example, indentions 186a and 186b (e.g., t-shaped indentions illustrated in <FIG>) are configured to prevent the tube from dislodging or "snaking" outside of the tube channel. As illustrated, the indentions 186a, 186b in door <NUM> are sized and shaped to prevent the tube <NUM> from "walking" out of valves 176a, 176b.

The door <NUM> may also include pegs or door latches 192a and 192b that correspond to door mounting apertures 194a and 194b in the pump housing. The door latches 192a, 192b engage with a slidable latch bar mechanism that is operatively connected to the slide clamp mechanism such that the slide clamp <NUM> can be inserted or ejected depending on a door open or a door closed position. For example, the latch bar mechanism may be spring biased towards the downstream side of the pump (e.g., to the left when looking at <FIG>) and as the door <NUM> is closed, the door latches 192a, 192b move the latch bar mechanism to the right as the door latches 192a, 192b are pressed into the pump housing.

The door <NUM> may also include a magnet <NUM> that is associated with a Hall effect sensor in the pump <NUM>. The Hall effect sensor is configured to detect the presence of magnet <NUM> to determine whether the door <NUM> is closed.

In an example, as a user begins to move the door <NUM> from an open position (illustrated in <FIG>) to a closed position (illustrated in <FIG>), at least one of the valves 176a, 176b may occlude the tube <NUM> during the closing process.

<FIG> depicts a high-level component diagram of an infusion pump system. The infusion pump system <NUM> includes a processor <NUM> in communication with memory <NUM>, which is powered by a battery or power supply <NUM>. The processor <NUM> communicates with a display <NUM>, a motor <NUM> and associated pumping mechanism <NUM>, and a communication module <NUM>. The pump system <NUM> also may include tube loading guidance modules <NUM>, such as a slide clamp indicator <NUM>, tube loading indicators <NUM>, and display instructions <NUM>. Additionally, the infusion pump system <NUM> may include various sensor modules <NUM>, such as a motor encoder <NUM>, an ultrasonic air sensor <NUM>, pressure sensors <NUM>, Hall effect sensors <NUM>, a slide clamp position sensor <NUM>, optical sensors <NUM>, temperature sensors <NUM>, an accelerometer <NUM>, and/or an ambient light sensor <NUM>.

The power supply <NUM> may take many different forms. In one preferred embodiment, the power supply <NUM> may be in the form of a rechargeable battery unit. Additionally, the pump may be powered from an AC power supply. The AC power supply assembly has a power cord and an associated terminal that plugs into the housing. The AC power supply assembly has a plug that can be inserted into a standard electrical outlet to recharge the rechargeable battery when necessary. The AC power can also be supplied through the assembly to power the pump.

The pump sub-assembly, as previously described, has associated therewith a plurality of sensors, which are operative to provide information as to the function and location of the various elements thereof. A drive motor shaft encoder comprises an encoder flag wheel attached to the armature shaft of the motor. The pump motor flag wheel may include a plurality of flags (e.g., twelve flags) extending radially outward from the hub thereof.

These flags act in concert with optical switches to fix the location of the armature shaft of the pump drive motor. The switches may further consist of a light emitting diode ("LED") and a photocell. An arrangement of two optical switches allows for a first switch to sense the edge of a flag, and the second switch to sense the middle of a subsequent flag. This arrangement allows for greater resolution of motor shaft position and direction as read by the encoder. For example, the resolution of the encoder may be approximately <NUM>/<NUM> of a rotation of the motor shaft.

The motor encoder senses shaft rotation directly. An index wheel may have a plurality of circumferentially coextensive radially disposed slots. Associated with these slots is an index wheel optical sensor. This sensor comprises a light emitting diode and an optical sensor or switch. In an example, the index wheel sensor is cooperative with the index wheel and the slots therein to provide positional information of the rotational location of the pump motor shaft.

In operation, the index wheel sensor acts in concert with the pump encoder to provide this positional information as well as directional information of the motor shaft. Associated with the shuttle itself is a linear gross position sensor. This sensor comprises a linear position Hall effect sensor and a plurality of magnets. Shuttle position sensor magnets present opposite poles to the shuttle Hall switch, so as to provide a field gradient operative to provide an indicium of the linear position of the shuttle.

The combination of the encoder and the other associated sensors aforementioned, provide inputs to a control mechanism, which may operate to accurately control the speed of the variable speed motor, the primary feature provided by such speed control is a temporal variability of the output of the pump. Additionally, such speed control allows for an electronically controlled linearization of the pump output per individual stroke as well as improving the time-integrated output of the pump.

The infusion pump may also include an ultrasonic air detection apparatus or transducer. The ultrasonic transducer acts in concert with a second transducer element to detect air within the IV tubing.

The pump allows the tube to be extended or stretched equally across the face of the associated sensor, thereby eliminating either a volumetric or stress gradient in the tube beneath the associated sensor so as to improve the accuracy of response of the sensor associated with, or connected to, housing. Essentially all of the sensors associated with, or actuated by, sensor arm execute the above described motion so as to achieve the above described result.

The pump may also include a downstream pressure sensor and a plurality of temperature sensors, which consist of thermistors.

The slide clamp may include a Hall effect sensor to identify the presence and/or position of the slide clamp <NUM>.

A solenoid actuated anti-free flow system automatically ejects the slide clamp <NUM>. The automated ejection of the slide clamp <NUM> utilizes various sensors discussed herein to improve patient safety (e.g., avoid a free flow condition) and decrease errors of slide clamp ejection by confirming vital systems in the pump prior to ejection. The ejection of the slide clamp <NUM> is automated after the system establishes that the IV tube is properly installed and loaded, the door is positively closed, and the respective sensors successfully perform system diagnostic checks.

In an example, a user may manually insert slide clamp <NUM> and then open door <NUM> of infusion pump <NUM> and the tube <NUM> may be positively held in an occluded state. After the door <NUM> is closed and proper loading is confirmed, the solenoid actuated anti-free flow system automatically ejects the slide clamp <NUM>.

Various sensors within the infusion pump may be used for diagnostic checks. Hall effect sensors in the slide clamp <NUM> may be used to confirm that a slide clamp <NUM> is present. Pressure sensors (e.g., pressure sensors 174a, 174b) may confirm proper IV tube loading. Additionally, a Hall effect sensor (e.g., Hall effect sensor in housing <NUM> and associated magnet <NUM> in door <NUM>) may confirm that the door <NUM> is closed. Optical sensors, such as optical IR sensors may confirm that the door is secured and latched. Additionally, pressure sensors may confirm that the door is closed and pressure is maintained. Hall effect sensors positioned within the latch may confirm that valve(s) are close. Any combination of the above sensors may be used for system diagnostic checks prior to slide clamp ejection. After the established set of sensors each successfully performs a system diagnostic check, a solenoid is energized and ejects the slide clamp <NUM>.

Slide clamp ejection may also be governed by auxiliary monitoring systems that confirm other vital information such as patient information, medication information, clinician information, and pump information. Auxiliary devices connected to the patient may be used to confirm acceptability of a drug based on the patient's vital data.

As illustrated in <FIG>, <FIG>, the solenoid <NUM> is positioned within the pump housing <NUM> above the slide clamp channel <NUM>. <FIG>, <FIG> illustrate several alternative embodiments for auto slide clamp ejection. As illustrated in <FIG>, the solenoid <NUM> may also be positioned about the side of the slide clamp channel.

<FIG> illustrates an example IV set loading sequence 500a. For example, when IV tube loading starts (block <NUM>), the Hall effect sensor in the slide clamp <NUM> detects that the slide clamp <NUM> is present (block <NUM>). Then, the door <NUM> is opened and the IV tube <NUM> is loaded, which is confirmed by a pressure sensor (e.g., pressure sensors 174a, 174b) (block <NUM>). Once the door <NUM> is closed, another Hall effect sensor (e.g., sensor associated with magnet <NUM>) confirms that the door <NUM> is in the closed position (block <NUM>) and an optical IR sensor confirms that the door link is latched (block <NUM>). Then a Hall effect sensor confirms that at least one valve (e.g., valves 176a, 176b) is closed such that the IV tube <NUM> is closed (block <NUM>). For each of blocks <NUM> to <NUM>, the pump may provide tube loading guidance (LED, display, audio, etc.) as further described below (block <NUM>). After each of the above sensors confirms that IV tube <NUM>, door <NUM>, and valve (e.g., valves 176a, 176b) are loaded and/or positioned, the pump <NUM> provides power to energize the solenoid (block <NUM>). Then, the solenoid is activated to automatically eject the slide clamp <NUM> (block <NUM>). Once the slide clamp <NUM> is ejected, the pump <NUM> may initiate an infusion (block <NUM>).

<FIG> illustrates an alternative IV set loading sequence 500b. For example, after the above sensors confirm loading and positioning of the pump components (e.g., blocks <NUM> to <NUM>), the pump may also confirm patient, medication, clinician (e.g., doctor or nurse), and/or pump information (block <NUM>). Patient's vital signs may also be confirmed through patient monitoring systems (block <NUM>). Then, the solenoid may be energized and ejected (blocks <NUM> and <NUM>) based on these additional safety checks and constraints.

Unlike systems that use mechanically timed slide clamp releases, the present disclosure provides additional patient safety that takes advantage of system diagnostic checks using a multitude of sensors to ensure proper tube loading and pump configuration.

Occlusions may be detected by monitoring force and/or pressure measurements using various techniques. Additionally, the user may select between rapid occlusion detection and non-rapid occlusion detection. In rapid occlusion detection mode, the syringe pump <NUM> may report an occlusion at <NUM>% of the force or pressure thresholds discussed below.

A baseline force value (e.g., a moving or sliding average window of force measurement samples, such as twenty samples) may be taken after the motor starts. The force and/or pressure sensor may output an Analog to Digital Converter ("ADC") count. In an example, the baseline force value may be a window of <NUM> samples of ADC counts after the pump motor starts. The current force measurement may be monitored and a difference value (e.g., baseline force value subtracted from the current value) may be determined. If the difference value exceeds a predetermined threshold, an occlusion alarm may sound. The pump may have various settings for various occlusion detection sensitivities (e.g., Very High, High, Medium High, Medium, Low, and Very Low).

In an example, the syringe pump <NUM> may generate a high priority downstream occlusion alarm for the following fluid pressures and sensitivities: (Sensitivity - Very High; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi); (Sensitivity - High; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi); (Sensitivity - Medium High; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi); (Sensitivity - Medium; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi); (Sensitivity - Low; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi); and (Sensitivity - Very Low; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi).

In another example, the syringe pump <NUM> may generate a high priority downstream occlusion alarm for the following fluid pressures and sensitivities: (Sensitivity - Very High; Occlusion pressure <NUM> psi; Limit < <NUM> psi); (Sensitivity - High; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi); (Sensitivity - Medium High; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi); (Sensitivity - Medium; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi); (Sensitivity - Low; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi); and (Sensitivity - Very Low; Occlusion pressure <NUM> psi; Lower Limit <NUM> psi; Upper Limit <NUM> psi).

For an infusion pump, the tubing relaxes into the channel causing a change in force, which is dependent on temperature. For example, the tube material properties change based on temperature and a temperature compensation slope may be added for both the baseline force value as well as current ADC values. However, for a syringe pump, the syringe force contact is non-relaxing in nature and a change in temperature does not cause a material property change. Also, the force sensor for the syringe pump is rated and compensated to operate from -<NUM> degrees to <NUM> degrees C, which covers typical pump operating ranges without affecting system level temperature variations in down stream occlusion ("DSO") detection for the syringe.

After the pump reaches steady state, occlusion detection may be based on a change in pressure or delta pressure instead of the High, Medium, or Low threshold settings. For example, after reaching steady state where the pressure is very steady, a sudden shift upwards for pressure may indicate that the pump is trending to occlusion. Monitoring a delta pressure after steady stay may allow for earlier occlusion detection.

In an example, steady state is achieved when there is less than a one (<NUM>) psi pressure change in the last two minutes of pressure measurements. If the system is not in a steady state condition, pressure delta sensing may be disabled.

The pump may also monitor changes in pressure as a function of flow rate. Different baseline and/or different threshold levels may be established based on the flow rate. For example, if the difference in pressure from baseline exceeds a predetermined relationship (e.g., pressure Increase = <NUM>*Flowrate in a <NUM> minute duration), an alert or warning for an occlusion sounds.

An occlusion alarm may be generated if the slope calculated from the difference of two pressure measurements exceeds a threshold value. The pressure measurements may be taken in a predetermined window or time interval, for example, every two seconds. In an example, two different slope measurements may be used to account for any braking forces at the start of an infusion. To prevent false alarms, the initial threshold value may be higher to account for braking forces from the tubing or other pump components at start-up. After start-up, the threshold value may be lower after the pump has overcome the braking forces.

Occlusion detection may also be based on energy spent or the area between a base line and the current force line. The area calculation may be compared to a threshold value.

False alarms are an increasing issue in the infusion world. Patient movement may result in pulls or tugs of downstream tubing. This patient movement often leads to line management issues and it becomes increasingly challenging to differentiate between a false alarm from a true occlusion.

A pressure may be monitored where the pressure is equal to the current ADC minus baseline ADC multiplied by a factor of (<NUM>/DistCalSlope) (e.g., Pressure = (Current ADC - Baseline ADC)* <NUM>/DistCalSlope). The current ADC may be a window or continuous moving average of <NUM> samples of ADC counts taken during the pumping phase at <NUM>. The baseline ADC may be a rolling sum of <NUM> samples of the first <NUM> ADC counts after the pump starts. The "DistCalSlope" term is a two-point slope (points taken at <NUM> psi and <NUM> psi) during manufacturing calibration. For example, the "DistCalSlope" term is equal to the difference of the ADC taken at <NUM> psi and <NUM> psi divided by the difference of the psi values (e.g., DistCalSlope = (ADC at <NUM> psi - ADC at <NUM> psi)/(<NUM>-<NUM>).

After the baseline ADC is determined, the baseline is held constant while the current ADCs are typically higher than the baseline ADCs. If the current ADCs are lower than the Baseline ADCs, then the baseline ADC may be updated to the current ADC. For example, the current ADC may be lower than baseline ADC due to tube relaxation and updating the baseline ADC to the current ADC accounts for the tube relaxation.

If the pressure calculated is greater than an established threshold, an occlusion is detected. Additionally, if an occlusion is detected, the pump may be stopped and a high priority occlusion alarm is communicated to the clinician.

As discussed above, the pump may have various settings for various occlusion detection sensitivities (e.g., Very High, High, Medium High, Medium, Low, and Very Low). Additionally, the lower limit may be updated to help distinguish tube-tugging and sudden drop scenarios from tube relaxation. In an example, if a tube pull or tug is detected, an alert or communication may be conveyed to the user to stop pulling on the tubing.

Digital moving average filters filter out unwanted spikes and/or noise signals. However, mechanically generated noise may also be unexpected and irregular which may lead to false alarms. In some instances, the mechanically generated noise may be more problematic than electrical noise.

An accelerometer may be used to help distinguish and/or filter mechanically induced sudden noises and/or spikes. Example sources of such noise may be from an operator pushing on the door of the infusion pump, an operator bumping into the pump, an operator moving the pump and patient while infusing, etc..

If the pump <NUM> drops from a height or an impact causes the pump to syphon or bolus, a separate high priority alarm can be sent to the user. If the accelerometer picks up mechanical movement/vibrations due to door movement or key selection (e.g., pressing display or physical keys), a feedback signal is sent to pump to not alarm or auto-restart because the event was purely caused by a sudden mechanically induced spike. Consequently, following an impact/drop a separate diagnostic algorithm is run on the sensors to test the functionality of the sensors and/or other critical components. For example, the diagnostic algorithm may ensure that the impact or drop did not disable or impair any of the sensor functions to ensure that the pump can detect and filter future vibration or drop events. When there is no impact but sudden irregular pressure spike(s) are detected by the occlusion algorithm, it can be confirmed from the accelerometer that it was purely electrically induced. If these spikes are sudden and irregular and not within an expected occlusion spike range an electrically induced sensor failure alarm is generated.

With an accelerometer sensitive enough to detect smaller movements/vibrations, a tubing tug or pulled scenario is confirmed in addition to the force sensor signal characteristics.

As illustrated in <FIG>, a moving average force sensor may monitor the forces applied to select locations on the pump (block <NUM>). If a disturbance, or sudden pressure/force spike is detected (block <NUM>), the system may check whether the accelerometer has detected an externally induced sudden or irregular disturbance (block <NUM>). If the accelerometer has detected an externally induced and irregular disturbance, the pump may disregard the force sensor disturbance (block <NUM>) and continue monitoring (block <NUM>). However, if the accelerometer has not detected an external event, the pump may generate a failure alarm signal to indicate an alarm condition, such as the presence of an occlusion (block <NUM>).

Sensors within the infusion pump may also be used for tube loading guidance. The IV set or tube loading guidance advantageously provides clinical staff with visual confirmation of proper IV set or tube loading to ensure patient safety during infusion preparation. In an example embodiment, the display and visual cues may be positioned on the pump to provide visual guidance to user's during IV tube loading. The pump may be configured to detect a user's presence in the pump's proximity. For example, a Long Wavelength Infrared ("LWIR") system may detect a user's presence in the pump's proximity. In another example, an ambient light sensor may be used to detect a user's presence. As a user approaches the pump, the pump detects the user's presence and if there is no IV tube loaded, a visual cue is provided to indicate where to insert the slide clamp. For example, an illuminated ring or other shape may indicate where to insert the slide clamp. Simple point LEDs may also indicate where to insert the slide clamp.

Initially, the pump may be powered on without an IV tube loaded. At this stage, a light indicator for slide clamp loading may be pulsing or blinking. The rate of pulsing or blinking may depend on whether the pump is running off battery power or is plugged-in and is using a power cord. The display may be used to support a user with further visual guidance prior to the door opening. Then, the user may insert the slide clamp. After inserting the slide clamp, the slide clamp light changes color while the door opens and the light indicator around the perimeter of the slide clamp is now in an "ON" state indicating the next step to the user. As the user loads the IV tube throughout the IV tube channel, various critical loading points may include other visual and audio guidance to complete the IV tube loading sequence.

As illustrated in <FIG>, a rectangular shape 610a (e.g., slide clamp area) is illuminated, for example in a yellow color (e.g., yellow pulsing light), to indicate where the slide clamp <NUM> should be inserted (e.g., slide clamp slot <NUM>). The color of illumination may also indicate that the slide clamp <NUM> has not yet been inserted (e.g., after insertion the yellow illumination may change to a green illumination). The display <NUM> may provide additional guidance to the user through instructions or prompts. For example, as illustrated in <FIG>, the display <NUM> may provide a message to the user, such as "To load the IV tube set, Insert slide clamp into opening.

After the user successfully loads the slide clamp <NUM>, the illuminated shape <NUM> (e.g., rectangle around the slide clamp area) may change from a yellow color (as illustrated in 8A as rectangular shape 610a) to a green color (as illustrated in <FIG> as rectangular shape 610b) to indicate that the slide clamp <NUM> has been loaded. For example, the change from yellow to green may serve as a confirmation that this stage in the tube loading sequence has been properly completed. At this point, the user may open the door <NUM> and additional visual cues such as (e.g., LED lights <NUM> and <NUM>) positioned behind the door, may guide the user for loading the tube. Once the door is opened, the display <NUM> is no longer visible to the user, and colored LEDs <NUM>, <NUM> are used to confirm various load points. In <FIG>, there are two different load points 670a, 670b that are indicated with LEDs <NUM>, <NUM>. Additionally LEDs or other visual cues may indicate other load points along the tube path.

The LEDs <NUM>, <NUM> may originally display a first color (e.g., red or orange) if the tube has not been loaded or has been improperly loaded. The LEDs <NUM>, <NUM> may then display a second color (e.g., green) once the tube has been properly loaded. In another example, the LEDs may pulse or blink to indicate whether a tube has been loaded. For example, a blinking LED may indicate that a tube is improperly loaded or unloaded and a solid colored LED may indicate that the tube is properly loaded at a respective load point. Initially, an indicator such as LED 650a may be pulsing orange to provide visual guidance and advise the user of the next tube-loading step. After the user loads the tube at a respective load point (e.g., load point 670a), the indicator (e.g., LED 650a) associated with that load point 670a may change from pulsing orange to a solid or steady green color. Then, the next indicator (e.g., LED 650b) associated with load point 670b may start pulsing to indicate the next loading step to the user.

Colors as well as animations may be used to indicate pump states and IV set or tube loading confirmations. For example, animations as well as pulsing, flashing or blinking lights may indicate the pump and IV tube loading states. It should be appreciated that any type of visual indicator or cue may be used and that LEDs are provided by way of example.

The pump may also use audible cues or tactile cues to inform or alert the user during tube loading. For example, the pump may use an assortment of beeps or vibrations to indicate the various stages of tube loading.

<FIG> illustrate example visual indicators during tube loading. In <FIG>, the slide clamp indicator area (e.g., rectangular shape 610b) is illuminated green after the slide clamp <NUM> has been successfully loaded. As the tube is loaded into each successive load point (e.g., load points 670a and 670b), the LED indicators <NUM> and <NUM> changes from red to green as illustrated in <FIG>. The LED indicators may also change from yellow to green or any other color combination. As shown, the LEDs <NUM>, <NUM> change from the first color to the second color once proper tube loading is detected and confirmed. Other visual indicators other than color may be used. Additionally, the indicators <NUM>, <NUM> may have various geometries and shapes (e.g., circle, ring, triangle, square, etc.).

As illustrated in <FIG>, the tube is properly loaded in load point 670a and the LED indicator <NUM> changes from a first color (illustrated as 650a) to a second color (illustrated as 650b) to provide a visual cue to the user that the tube has been properly loaded. As discussed above, other cues may be provided to the user such as an audible beep. At this point in <FIG>, the tube has not yet been loaded into load point 670b, so LED indicator <NUM> is still in the first color (illustrated as 660a) to indicate that the tube has not been properly loaded at that load point.

As illustrated in <FIG>, the tube is properly loaded in load point 670b and the LED indicator <NUM> changes from a first color (illustrated as 660a) to a second color (illustrated as 660b) to provide a visual cue to the user that the tube has been properly loaded at that respective load point. After the tube has been properly loaded and the door is closed, the pump may be ready to program an infusion. Then, the slide clamp indicator area (e.g., rectangular shape 610b) may be activated in a different color to indicate to the user to eject the slide clamp and start the infusion.

As discussed herein, ejection of the slide clamp occurs automatically after confirmation from various sensors. Upon infusion completion, the slide clamp area may again be indicated by a light so that the door can again be opened by inserting the slide clamp.

In addition to color indication for slide clamp and tube loading guidance, LEDs may be cycled to indicate various stages of IV tube loading. For example, if a load has not yet been attempted, the LED may slowly pulse. If a load is completed successfully, the LEDs may be permanently on. Various LED colors may also be used to further distinguish the tube loading stages. Yellow may be used in a slow pulse or where the LED is slowly "breathing" to indicate that a load has not yet been attempted. Green may be used when the load is completed successfully, and the LEDs may be colored red when flashing to indicate that the load was not successful or that the IV popped out of a load point.

The guidance described herein advantageously improves patient safety by enhancing IV tube loading (e.g., insertion) guidance with confirmation of each completed loading step via visual and acoustic guidance. For example, tri-color or discrete color LEDS, light-guides, diffusers, light-guides with integrated diffusers, display screens, speakers and other acoustic elements (or a combination thereof) may be positioned on the pump and activated in specific combinations or sequences to provide guidance to the user while loading an IV tube.

The LEDs (e.g., <NUM>, <NUM>, <NUM> of <FIG> or <NUM>, 950a-c of <FIG>) may also be used to indicate the pump is "ON" as well as flow direction. In some examples (e.g., with multi-colored LEDs such as tri-colored LEDs) the LEDs may be used to indicate some of the basic pump states when the display is off to reduce power consumption as illustrated in <FIG>. As illustrated in <FIG>, the load point LEDs (e.g., 950a-c) may be integrated on the external edge of the pump for improved visibility. Additionally, the LEDs 950a-c may be used to indicate pump status in a low power state consumption level.

The visual cues and/or other indicators such as audible cues and tactile cues may work in conjunction with the display to provide guidance and information to a user.

Operation of each of the above modes may be changed within the pump settings. Additionally, the display may depend on whether operation is from the power cord or battery. For example, to conserve the battery, the LED (e.g., <NUM>, <NUM>, <NUM> of <FIG> or <NUM>, 950a-c of <FIG>) and other light indicators may be used. However, when operating via a power cord, both the LED/light indicators and the display may be used to provide visual indications and prompts to the user.

The infusion pump disclosed herein and/or a syringe pump may be used with a rack configured to house one or more pumps (e.g., infusion and/or syringe pumps). The rack may provide dynamic power and heat management for each pump housing within the rack. The power and heat management may be based on medication criticality that each respective pump is delivering. For example, a pump housed in the rack that is delivering a highly critical medication may be allocated more power so that the battery is charged to a level that reduces risk to the patient from a depleted battery after AC has been removed.

The rack may assist with pump identification, pump-to-pump communication, pump-to-rack and rack-to-pump communication, pump battery charging, etc. The rack may also manage power based on medication criticality and may also manage motor consumption per medication needs.

The rack may provide a common display and external connectivity via a wired or wireless connection.

The rack may implement several methods or procedures to control battery consumption and charging of the various infusion pumps and/or syringe pumps housed in the rack. The rack may allow a pump power supply or wall wart to draw higher current for faster charging. For example, the rack may allocate rack power to each pump such that its battery will be charged to a level that reduces risk to a patient from a depleted battery after AC-power has been removed. If a patient is receiving a critical medication along with a noncritical IV solution, the pump delivering the critical therapy may be given charging priority such that it is allowed to charge its battery faster than other pumps housed in the rack. The rack may also manage the amount of power that a pump is using for things other than battery charging, such as driving its motor. If one pump is using more power to drive its motor then that pump may be allowed to have a higher charge current so that when unplugged, the run time on the battery will be similar for all pumps housed in the rack. The rack may also prioritize and assign fast charging vs. trickle charging on a pump-to-pump basis based on criteria, such as charge need, medication being delivered, etc..

The rack may also detect failure modes, such as exceeding thermal constraints on power supplies.

Claim 1:
An infusion pump (<NUM>) comprising:
a housing (<NUM>) with a door (<NUM>) pivotally mounted to the housing;
a tube channel (<NUM>) positioned at least partially behind the door on the housing, the tube channel configured to hold an IV tube (<NUM>) in the infusion pump;
a pumping mechanism (<NUM>) including a shuttle positioned behind the door;
a slide clamp channel (<NUM>) for receiving a slide clamp (<NUM>),
characterized in that the infusion pump further comprises:
a slide clamp ejection device including a solenoid (<NUM>) configured to automatically eject the slide clamp (<NUM>) from the slide clamp channel such that the slide clamp will no longer occlude the IV tube, and
sensors arranged on the infusion pump including a first Hall effect sensor (<NUM>) configured to detect when the door is positioned in a closed state, an optical sensor such as an optical IR sensor (<NUM>) configured to detect when the door is latched while positioned in the closed state, and a pressure sensor (174a, 174b) configured to detect the presence of the tube at a load point along the tube channel,
wherein the slide clamp is automatically ejected from the slide clamp channel when inputs from the sensors establish that the IV tube is properly installed and loaded and the door is closed and latched.