Automated enteral nutrition
11147745 · 2021-10-19
Assignee
Inventors
- Christoph Ganter (Zurich, CH)
- Michael Jedwab (Lausanne, CH)
- Dorion Benjamin (Martigny, CH)
- Natalia Muehlemann (Territet, CH)
- Eric Johnson (Long Lake, MN, US)
- Steven Bernard (Eden Prairie, MN, US)
Cpc classification
A61M5/1723
HUMAN NECESSITIES
A61J15/0011
HUMAN NECESSITIES
International classification
A61M5/168
HUMAN NECESSITIES
Abstract
A system can automatically adjust flow rates/feeding regimen of a feeding pump feeding fluids/enteral nutrition to a patient. The system can, based upon a prescribed volume of nutrition or nutritional targets (such as and not limited to energy (calories), protein etc.) to be delivered and a prescribed delivery duration, adjust the pump flow rate/feeding regimen following unexpected delivery interruptions to achieve at or near to the prescribed total volume/nutritional targets to be delivered, despite the interruptions.
Claims
1. A pump system for delivering an enteral nutrition composition, the pump system comprising: a pump, an input device, a controller, a memory device and a processor, the processor configured to execute instructions stored on the memory device to cause the controller to: via the input device, enable a user to input a first nutrition parameter and a first duration of a nutrition delivery (T1), wherein the first nutrition parameter is a first nutrition volume to be delivered (V1); calculate a first delivery flow rate (F1) of the pump based upon the first nutrition volume (V1) and the first duration (T1); start the pump according to the first delivery flow rate (F1); stop the pump in the event of a pump interruption of a second duration, wherein the second duration is an interruption duration (I); determine if the interruption duration exceeds an interruption duration threshold; if the interruption duration does not exceed the interruption duration threshold, continue operating the pump according to the first delivery flow rate; and if the interruption duration exceeds the interruption duration threshold, after the conclusion the pump interruption: calculate a partial nutrition volume delivered (V2) and a remaining nutrition volume to be delivered (V3), wherein: V1=V2+V3; calculate a partial time duration completed (T2) and a remaining time duration (T3), wherein T1=T2+T3; and calculate a proposed delivery flow rate (F2) of the pump based upon the remaining nutrition volume to be delivered and the remaining time duration, wherein the instructions include a maximum allowable flow rate of the pump; determine if the proposed delivery flow rate exceeds the maximum allowable flow rate; and if the proposed delivery flow rate does not exceed the maximum allowable flow rate, resume the pump according to the proposed delivery flow rate, wherein the proposed delivery flow rate of the pump is higher than the first delivery flow rate of the pump.
2. The pump system of claim 1, wherein the first delivery flow rate of the pump is calculated based additionally on at least one of a first nutrition energy target to be delivered (E1) or a first nutrition protein target to be delivered (P1).
3. The pump system of claim 1, which includes calculating a proposed nutrition regimen for intermittent feeding.
4. A method for controlling a pump for delivering an enteral nutritional composition, the method comprising the steps of: receiving a first nutrition parameter and a first duration of nutrition delivery (T1) defining at least a portion of a prescription, wherein the first nutrition parameter is a first nutrition volume to be delivered (V1); starting the pump with a first delivery flow rate calculated based upon the first nutrition volume to be delivered (V1) and the first duration of nutrition delivery (T1) of the prescription; stopping the pump in the event of a pump interruption of a second duration, wherein the second duration is an interruption duration; determining if the interruption duration exceeds an interruption duration threshold: if the interruption duration does not exceed the interruption duration threshold, continue operating the pump according to the first delivery flow rate; and if the interruption duration exceeds the interruption duration threshold: after the second duration, calculate a proposed delivery flow rate based upon a duration of partial time remaining (TR) from the first duration of nutrition delivery of the prescription and a partial volume of the nutrition delivered (VR) from the first nutrition volume of the prescription; determining if the proposed delivery flow rate exceeds a maximum allowable flow rate of the pump; wherein, if the proposed delivery flow rate does not exceed the maximum allowable flow rate, restarting the pump after the pump interruption has concluded at the proposed delivery flow rate for the duration of partial time remaining or until a subsequent interruption, wherein the proposed delivery flow rate of the pump is higher than the first delivery flow rate of the pump, and wherein the proposed delivery flow rate is calculated to enable the pump to deliver the first nutrition volume within the first duration of nutrition delivery of the prescription notwithstanding the pump interruption.
5. The method of claim 4, wherein the first delivery flow rate of the pump is calculated based additionally on at least one of a first nutrition energy target to be delivered (E1) or a first nutrition protein target to be delivered (P1).
6. The method of claim 4, which includes calculating a proposed nutrition regimen for intermittent feeding.
7. The method of claim 4, which includes defining the maximum allowable flow rate of the pump.
8. A non-transitory machine-readable storage medium comprising machine-readable instructions for causing a processor to execute a method for use with a medical device and an associated pump to automate enteral nutrition delivery, the method comprising: receiving a first nutrition parameter and a first duration of nutrition delivery (T1) defining at least a portion of a prescription, wherein the first nutrition parameter is a first nutrition volume to be delivered (V1); starting the pump at a first delivery flow rate calculated based upon the first nutrition volume to be delivered (V1) and the first duration of nutrition delivery (T1) of the prescription; stopping the pump in the event of a pump interruption of a second duration, wherein the second duration is an interruption duration; determining if the interruption duration exceeds an interruption duration threshold: if the interruption duration does not exceed the interruption duration threshold, continue operating the pump according to the first delivery flow rate; and if the interruption duration exceeds the interruption duration threshold, after the second duration has concluded, calculate a proposed delivery flow rate based upon a duration of partial time remaining (TR) from the first duration of nutrition delivery of the prescription and a partial volume of the nutrition delivered (VR) from the first nutrition volume of the prescription; and comparing the proposed delivery flow rate with a maximum allowable flow rate: if the proposed delivery flow rate exceeds the maximum allowable flow rate: restarting the pump at the maximum allowable flow rate; and calculating and displaying the maximum allowable flow rate on a display device associated with the pump; and if the proposed delivery flow rate does not exceed the maximum allowable flow rate, restarting the pump at the proposed delivery flow rate, wherein the proposed delivery flow rate of the pump is higher than the first delivery flow rate of the pump.
9. The non-transitory machine-readable storage medium of claim 8, wherein the first delivery flow rate of the pump is calculated based additionally on a first nutrition energy target to be delivered (E1).
10. The non-transitory machine-readable storage medium of claim 9, further comprising the step of defining an energy density of the prescription.
11. The non-transitory machine-readable storage medium of claim 8, wherein the first delivery flow rate of the pump is calculated based additionally on a first nutrition protein target to be delivered (P1).
12. The non-transitory machine-readable storage medium of claim 11, further comprising defining a protein ratio of the prescription.
13. The non-transitory machine-readable storage medium of claim 8, further comprising defining at least one maximum allowed intermittent feeding parameter.
14. The non-transitory machine-readable storage medium of claim 13, wherein the maximum allowable flow rate and the at least one maximum allowed intermittent feeding parameter can be modified by a user.
Description
BRIEF DESCRIPTION OF THE FIGURES
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DETAILED DESCRIPTION
(10) As used in this disclosure and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a fluid” or “the fluid” includes two or more fluids.
(11) The words “comprise,” “comprises” and “comprising” are to be interpreted inclusively rather than exclusively. Likewise, the terms “include,” “including” and “or” should all be construed to be inclusive, unless such a construction is clearly prohibited from the context.
(12) Nevertheless, the devices and apparatuses disclosed herein may lack any element that is not specifically disclosed. Thus, a disclosure of an embodiment using the term “comprising” includes a disclosure of embodiments “consisting essentially of” and “consisting of” the components identified. Similarly, the methods disclosed herein may lack any step that is not specifically disclosed herein. Thus, a disclosure of an embodiment using the term “comprising” includes a disclosure of embodiments “consisting essentially of” and “consisting of” the steps identified.
(13) The term “and/or” used in the context of “X and/or Y” should be interpreted as “X,” or “Y,” or “X and Y.” Where used herein, the terms “example” and “such as,” particularly when followed by a listing of terms, are merely exemplary and illustrative and should not be deemed to be exclusive or comprehensive. Any embodiment disclosed herein can be combined with any other embodiment disclosed herein unless explicitly stated otherwise.
(14) As used herein, “about” and “approximately” are understood to refer to numbers in a range of numerals, for example the range of −10% to +10% of the referenced number, preferably within −5% to +5% of the referenced number, more preferably within −1% to +1% of the referenced number, most preferably within −0.1% to +0.1% of the referenced number.
(15) Enteral feeding pumps are devices that control the timing and the amount of nutrition delivered to a patient during enteral feeding. Enteral feeding is the administration of nutrient fluids to a patient who cannot eat via normal ingestion routes. Enteral administration typically occurs through a set of tubes between a feeding bag and a catheter inserted into the patient. A disposable cassette typically carries at least a portion of the tubing so that spent tubing may be easily disposed of.
(16) Enteral feeding pumps can operate as part of a stand-alone nutrition delivery system or as part of a larger interconnected network of pumping apparatuses, controllers, servers, and databases. For various enteral feeding administrations, a doctor or clinician provides a prescription for an amount (e.g., volume, calories) and duration of continuous feeding or intermittent feeding regimen based upon the profile of each individual patient. It should be appreciated that various enteral feeding pump systems of the present disclosure are configured to enable the input of a feeding prescription, whether via a controller at the pump itself or a controller at a remote or separated server connected to the pump via a suitable network. In some embodiments, a controller associated with the pump is configured to operate the pumping speed, nutrition/enteral fluid delivery duration, and pumping timing based upon a variety of factors controllable by one or more of the patient, the clinician, indirectly by the prescription, and/or automatically by the pump controller.
(17) In various embodiments of the present disclosure, an enteral feeding pump system includes an associated user interface or suitable display device (collectively hereinafter “user interface”) that enables interaction between the patient or clinician and the pump system via a suitable associated input device. In various embodiments, a user or clinician, via the input device and user interface, has the ability to at least program the pump with pumping parameters, input a patient prescription, and monitor a continuous or intermittent enteral feeding pump delivery. It should be appreciated that such pump programming inputs may be achieved remotely according to known remote programming methods, as well as locally using an associated input device.
(18) In various embodiments, a typical prescription for a pump system of the present disclosure defines at least one or more of: (1) a volume of nutrition to be delivered to the patient; (2) a flow rate profile controlling the rate of delivery of the nutrition to the patient; (3) a duration or time period during which the total nutrition is expected to be delivered to the patient; (4) energy prescribed to the patient; (5) protein or other macro/micronutrient prescribed per day over the determined period; and (6) type of nutrition (e.g., hyperproteinin or hypercaloric). In various embodiments with intermittent deliveries, a prescription could also include planned delivery stops (as discussed and illustrated in more detail below), planned interruptions, bolus feeds, and minimum and maximums on bolus feeds, maximum allowed intermittent feeding parameters, pre-planned interruption durations, flow rate, catch-up flow rate, and over-delivery flow rates. The embodiments discussed herein can be used not only for nutrition delivery, but also for hydration of a patient. For example, in various hydrating embodiments, the fluid delivered can be water or tea.
(19) In various embodiments, the pump includes an interruption duration threshold, short of which, the pump does not go through the full recalibration and flow rate adjustment calculation and resetting described herein. For example, in one embodiment, if a delivery system experiences a plurality of minor pauses that are very short in duration (or pump interruptions), the feeding stops may not aggregate to a significant enough interruption to warrant recalculation of flow rates or total fluid delivered during the feeding. In various embodiments, the feeding stops, pauses, or pump interruptions may be upstream or downstream occlusions of the feeding lines, temporary power outages to the pump, or other abnormalities detected in the nutrition delivery, such as air detected in the feeding lines, short manual stoppage of the pump for any known reasons, pump errors causing a pause in delivery, or outputs from pump sensors indicating readings that exceed threshold safety values stored in the pump memory device.
(20) It should be appreciated that, while an acceptable number of pump interruptions may be abbreviated enough in aggregate to not adversely affect the overall delivery, the pump system of various embodiments monitors the total interruption duration and compares it to a preset or a predefined threshold. In some embodiments, the predetermined threshold is a parameter of an inputted or calculated duration for the particular delivery. If, for example, the pump interruptions include a plurality of short occlusions or interruptions whose cumulative duration falls short of the predetermined threshold parameter, the pump continues with the feeding without adjustment or recalculation. If, on the other hand, the cumulative duration of the short occlusions or interruptions exceeds the predetermined threshold parameter (e.g., more than 1 or 2 minutes), the pump system recalculates flow rates to ensure accurate nutrition delivery in any of the manners described herein.
(21) It should be appreciated that each of the above parameters can be defined directly by the operator via the prescription, or can be calculated directly or indirectly based upon one or more parameters or other variables. For example, in various embodiments, the volume to be delivered divided by the average flow rate of the pump will calculate the total duration of delivery. In various embodiments, the volume to be delivered can be calculated from information on the bar code or other suitable identification mechanism situated on the feeding bag or the product. In various embodiments the barcode can also inform the pump of the type of feed and display that information on the display device. It should be appreciated that, because the pump is informed of the type of feed, the display can update the user in real time of the accumulated parameters of the delivered feed, such as the amount of protein or calories.
(22) During continuous enteral feeding, for various reasons, a patient may need to pause the nutrition delivery for a period of time. For example, enteral nutrition can be held or discontinued varying periods of time for diagnostic or therapeutic interventions undergo different procedures (including, but not limited to, bed side procedures, extubation/intubation, operating room procedures, or procedures in radiology suite). Patients may wish to be ambulatory away from the pump system, the reservoir or source of nutrition being fed to the patient may need replenishment, or the treatment may be interrupted for any other expected or unexpected reason, such as X-ray or other screening assessment. In various embodiments of the present disclosure, such a pause is enabled by instructing the controller to stop the pump via the suitable input device. Additionally, some embodiments include a controller that causes the pump to automatically interrupt nutrition delivery for various reasons.
(23) During intermittent enteral feeding the prescription is subdivided over several feeding sessions with one or more planned delivery stops (as opposed to interruptions). Unexpected interruptions often disrupt intermittent feeding just as they do for continuous feeding. Therefore, it should be appreciated that the discussion herein of interruptions (expected or unexpected) can be remedied by the methods described for both intermittent and continuous feedings.
(24) In the event of a nutrition delivery interruption, one or more of the defined pump parameters from the prescription will be affected, which could affect one or more of the calculated pump parameters. Therefore, an interruption in nutrition delivery may result in the failure to complete the prescription according to its intended requirements. For example, as most prior systems operate, if the pump flow rate is a defined parameter, and the total duration of the delivery is a defined parameter, an interruption will effectively result in a lower duration of active pumping time at the set pump flow rate, and therefore less than the intended total nutrition will be delivered to the patient. It is also possible (common case in current practice) that none of the pump parameters are affected (because most commonly used parameter is flow rate for continuous feeding) and when resuming delivery after pump pausing pump will continue delivery leading to under-delivery which may not be noticed in the absence of nutrition delivery monitoring (either in connection with information system or manually). Recent study across 160+ intensive care units (“ICUs”) in many countries showed that on average only 60% of prescribed calories and protein are delivered to ICU patients. In the present disclosure, however, if the volume/nutrition targets and duration are both defined parameters and the flow rate is a calculated parameter, the automatic flow rate adjustment described herein (e.g., catch-up flow rate) enables the system to mitigate any deficiency of nutrition volume delivered to the patient in the event of an interruption.
(25) Regardless of the reason for a pump interruption, the source causing the pump interruption, or which prescription parameters are defined and which are calculated, it should be appreciated that an interrupting event of any duration affects the volume/target of the total expected nutrition delivery as prescribed by the prescription. As discussed in greater detail below, one way to ameliorate the undesirable effects of a planned or unplanned delivery interrupting event is to cause the pump to adjust its flow rate (or feeding regimen for intermittent mode) to make up for the duration of the interruption without sacrificing the overall volume/calories to be delivered. For purposes of discussion, any adjustment of the flow rate or feeding regimen of the pump to compensate for pump down-time during an interruption or delivery pause will be referred to as a “catch-up flow rate”. Typically, although not always, the catch-up flow rate is a higher rate than the programmed or calculated flow rate intended by the prescription for the nutrition administration. It should be appreciated that the catch-up flow rate, while typically being higher than the programmed flow rate, can also be subject to a pre-set maximum allowable catch-up flow rate restriction (pre-set parameters of intermittent regimen). Based upon one or more of the patient's condition, the patient's parameters and metrics, the nutrition profile, or any part of the enteral feeding prescription, the enteral feeding pump can be restricted to a maximum flow rate, beyond which neither the prescribed delivery flow rate nor the catch-up flow rate are allowed to exceed. It should be appreciated that the pre-set maximum allowable catch-up flow rate may differ from a pre-set maximum allowable prescribed flow rate. In various embodiments, the catch-up flow rate may vary from the pre-set flow rates.
(26) In various embodiments, the volume/target of the total expected nutrition delivery as prescribed by the prescription is adjusted in anticipation of a potential interruption. Whether planned or unplanned, based upon past feedings, the presence of delivery interruptions can be predicted with a reasonable degree of likelihood. In such cases where a regimen will likely include an interruption, the pump can be programmed to adjust its flow rate higher before an interruption so that, when such an interruption occurs, the patient has already received excess nutrition compared with the programmed flow rate. Because the patient is ahead of schedule from the over-delivery, the anticipated interruption has an excess of nutrition from which to offset the nutrition shortage resulting from pump downtime, and the regimen more closely matches the prescription following the interruption. It should be appreciated that such an embodiment includes a preemptive increased flow rate, which is similar to a catch-up flow rate discussed above. By using a preemptive increased flow rate, the pump need not aggressively max out a catch-up flow rate following an interruption.
(27) In various embodiments, the pump system is an adaptive pump system that is programmed to receive a variety of different inputs related to predicted interruptions. One such adaptive pump system proactively anticipates or predicts interruptions based upon the inputs (e.g., past interruptions typical to the particular patient, institution, facility, or clinician) and modifies the calculated pump delivery flow rate(s) similar to the preemptive increased flow rate discussed above. For example, in one such adaptive pump system embodiment, a hypothetical patient has in the past been typically disconnected for approximately 30 minutes at 10:00 am to be bathed and for the room to be cleaned. For the first few days of this consistent interruption, the adaptive pump system would record those interruptions and learn from those events to create an input and instruct the system to modify its preemptive flow rate in future deliveries to compensate for the likely 30 minute 10:00 am interruption. In one such situation, for example, the preemptive flow rate may need to be 10% higher to compensate for the planned 30 minute interruption and still achieve 100% of the feeding volume prescribed. It should be appreciated that, the more anticipated or predicted interruptions, and the longer the duration of the sum total of interruptions predicted, the higher preemptive flow rate adjustment made to the delivery.
(28) The adaptive pump system of this and other embodiments avoids the potentially undesirable situation in which the patient falls short of the optimal 100% prescribed feeding volume delivered on account of an interruption that was wholly predictable. It should be appreciated that various adaptive pump systems of the current disclosure can incorporate any conceived number of inputs of known scenarios that may result in anticipated or predicted interruptions in a patient's feeding regimen.
(29) It should be appreciated that, by using an associated memory device or data connection and the inputs regarding anticipated interruptions, the adaptive pump system of the present disclosure can also learn and track the likelihood of future interruptions actually occurring vs. those that were planned or budgeted in the modification of the preemptive flow rate. For example, if the above hypothetical 30 minute interruption were to occur three consecutive days at 10:00 am, the adaptive pump system of one embodiment would be able to assign a high degree of likelihood that the same interruption would occur on the fourth day as well. It should be appreciated that, as the accuracy of its predictions changes and the pump is dynamically updated based upon actual occurrences, the adaptive pump system can also adjust the preemptive flow rate associated with the predicted interruption accordingly. For example, if the likelihood of the 30 minute interruption at 10:00 am has decreased significantly, yet the interruption still has some chance of occurring, the adaptive pump system could automatically hedge the chance that the interruption occurs by reducing the preemptive flow rate to deliver only 5% more than prescription, rather than 10% more than prescription. It should be appreciated that various different factors can incorporated into the preemptive flow rate delivery modification.
(30) In some adaptive pump system embodiments, the interruption prediction inputs which are tracked and modified are either patient-specific or institution-specific. It should be appreciated that the patient-specific inputs may be discerned from clinician or user-provided information as well as past data regarding interruptions experienced. The institution-specific inputs to the adaptive pump system may be affected by the nurse associated with the specific patient, the unit of the institution the patient is admitted into, or any other known hospital or institutional variables that may affect or interrupt a patient's feeding regimen.
(31) It should be appreciated that, in various embodiments, the preemptive flow rate and catch-up flow rate can both be used together as well. For example, in one exemplary feeding regimen, if an interruption is long enough, even maxing out the catch-up flow rate following the interruption may not be sufficient to deliver the entire prescription. In such a case, employing a hybrid that also uses a preemptive flow rate increase would build up reserves of the nutrition delivered beyond that of the expected prescribed delivery, so that following the unusually long interruption, the catch-up flow rate (if necessary) can be set appropriately to deliver the full volume to the patient as prescribed.
(32) In various embodiments the pump is programmed to deliver an intermittent rather than continuous feeding regimen. In such an embodiment, the system is programmed with maximum allowed intermittent feeding parameters. One such example includes parameters suggested by the pumps but requiring confirmation or modification by the user or clinician to account for individual patient tolerance, symptoms, and/or condition. As discussed in greater detail below, during an intermittent feeding regimen, a prescription could include pre-planned feeding stops of set durations. In various embodiments, a bolus feed is pre-planned at various stages of the delivery (both continuous and intermittent). In intermittent embodiments which bolus feeds are missed during a stop (planned or not), the planned duration of feeding stops can be decreased to achieve all boluses. Alternatively, if a bolus feed is missed, rather than adjusting the planned duration of the feeding stop, future bolus amounts could be increased to meet the total delivery. It should be appreciated that another alternative embodiment uses a combination of both methods to achieve full delivery: shortening stop duration and increasing future bolus amounts. For safety, a minimum bolus interval and a maximum bolus amount could be included in the prescription. It should be appreciated that a range of parameters could also be used to make up for the shortfall, such as time, flow rate, or caloric density.
(33) In some embodiments, a doctor or clinician is granted permission to manually override any one of the maximum flow rate restrictions (e.g., pre-set maximum allowable catch-up flow rate and a pre-set maximum allowable prescribed flow rate and a pre-set maximum allowable preemptive flow rate). In one such embodiment, the system notifies the doctor or clinician that a pre-set by pump or by a clinician maximum flow rate has been reached, and provides the option to exceed the pre-set maximum flow rate. In an intermittent delivery embodiment, the doctor or clinician is granted permission to manually override any one of the minimum or maximum bolus feed amounts, planned stop duration, as well as the above-described flow rate restrictions.
(34) In one embodiment, safety may be increased for a patient on insulin infusion by a mandatory validation (by a healthcare professional) of all changes of feed rates proposed by the pump system. Examples of such changes requiring validation are those that may have implication on insulin infusion.
(35) While failing to complete a prescription is undesirable and should be avoided if possible, such situations are often times unavoidable when an interruption is long enough. In some situations, the pre-set maximum allowable catch-up flow rate is still insufficient to deliver the total prescribed nutrition within the prescribed delivery time. In such cases, it is beneficial to calculate and inform the user and/or clinician as to the percentage of partial prescription that will be completed within the delivery time frame prescribed. It may be resolved by changing prescription to higher calorie density enteral formula within the limits of the patient's tolerance.
(36) For example, in one embodiment discussed in greater detail below, the duration of a delivery interruption exceeds the amount of time for which a maximum allowable catch-up flow rate could fully compensate within the prescribed delivery time. In such an instance, the pump system is configured to calculate and display a delivery status to the user including how much of the prescribed delivery can be delivered according to the maximum allowable catch-up flow rate. In various embodiments, the displayed delivery status includes a real-time updating percentage of how much of the prescribed nutrition will be delivered based upon varying flow rate profiles. Additionally, in various embodiments, the display device can include a status of a real-time updating percentage of how much prescribed nutrition has been actually delivered at that point in the feeding. It can also display daily or cumulated nutritional deficit (e.g., calorie or protein). As flow rates change throughout the enteral feeding delivery (whether the prescribed flow rate, the catch-up flow rate, or another transitional flow rate), the pump system is configured to automatically readjust and display the expected total delivery percentage or actual volume or calorie/other nutrient deficit expressed accordingly (e.g., kcal). The extrapolations calculated and displayed can be, but are not necessarily, linear based upon a first flow rate and a second catch-up flow rate. The real-time updated delivery percentage status can also be dynamically adjusted based upon a plurality of proposed flow rates vs. actual flow rates, taking into account ramp-up flow rates and actual nutrition volume delivered, rather than predicted nutrition volume delivered.
(37) In one example embodiment, a prescription was not fully delivered within the prescribed delivery time, even when operating at the maximum allowable catch-up flow rate. When the pump system has resumed following an interruption, and the resumption is set at the maximum allowable catch-up flow rate, the system of one embodiment automatically extrapolates the maximum amount of nutrition that can be delivered in at the maximum allowable catch-up flow rate within the amount of time remaining in the prescription. The pump will provide an extended delivery option to achieve full prescription delivery.
(38) For example, if after an interruption, the prescription is 80% delivered, the pump system will calculate that, even at the maximum allowable catch-up flow rate for the remainder of the delivery, the prescription will only be 90% delivered at the end of the allotted time. In such an embodiment, the pump system will calculate that the delivery will not hit 100% of the prescription within the allotted time and notify the patient or clinician accordingly. In one exemplary embodiment, the pump system provides an option to extend the time of the delivery by a calculated duration to achieve 100% delivery of the nutrition. In the embodiment discussed above, at the time of resumption of delivery following an interruption, the pump system can notify the patient that, although 80% of the delivery has been completed, even under the maximum allowable catch-up flow rate, only 90% can be delivered. However, if the patient or clinician is willing to extend the delivery time by a calculated duration of time, 100% of the nutrition can be delivered. It should be appreciated that the pump system can be configured to calculate the extended delivery duration based on an assumed maximum allowable catch-up flow rate, an override flow rate from a clinician, or any other suitable flow rate encountered during the delivery described herein. See
(39) In an intermittent embodiment, also displayed and illustrated below, the duration of one or more planned delivery stops can be adjusted based upon unplanned interruptions. Additionally, the existence and duration of one or more planned delivery stops can affect the catch-up flow rate and the urgency which the system attempts to realign the feeding flow profile with that of its prescription. In other words, if an intermittent delivery has five planned stops, and after the first planned stop is 20% behind prescription due to unplanned interruptions, the system can readjust the catch-up flow rate to more conservatively reach 100% delivery by the end of all the feeding sessions than if there were only two planned stops. In the first five-stop scenario, after the first stop, the system knows there will be five more feeding sessions during which the relative 20% deficit can be compensated. In the second two-stop scenario, however, there are only two subsequent feeding sessions to make up for the 20% deficit at the time of the first stop. Therefore, the second scenario would require a more aggressive catch-up flow rate or over-delivery flow rate for the fewer remaining feeding sessions than the first scenario. It should be appreciated that, in each case, the intermittent delivery system could include an over-delivery flow rate planned into the prescription to target an early completion in the anticipation of interruptions or missed bolus feedings. Additionally, for both illustrative examples, the catch-up/over-delivery flow rates could be increased in conjunction with the stop duration being decreased as necessary to reach 100% delivery.
(40) Referring now to
(41) As seen in the flow profile 100, the delivery has a total duration of E minutes, and during that duration, delivery was interrupted twice, as illustrated by the dashed lines defining time period X and time period Y. The top chart 110 illustrates the initial pump flow rate F ml/min, which is programmed by the system according to a prescription. Flow rate line 112 shows that the pump continues a constant flow rate F from the beginning of delivery until the beginning of interruption X, marked at X1 minutes. When the delivery is interrupted at X1 minutes, the pump's flow rate goes from F ml/min to 0 ml/min, as depicted by flow rate line 114, which continues until the interruption X is over and the system resumes pumping, marked at X2 minutes.
(42) It should be appreciated that, according to such a prior art delivery profile, because the prescription is flow-rate based, rather than volume-based, the flow rate of the pump is static and therefore resumes after an interruption as if the interruption never happened. As seen in chart 110, flow rate line 116 indicates that the pump is switched back on at the prescribed pump flow rate F ml/min after the X interruption concludes at time X2 minutes. The delivery in chart 110 continues until the second interruption Y begins, marked at Y1 minutes. Similar to the first interruption X, this second interruption Y results in the pump being switched off and flow rate going to 0 ml/min, as indicated by flow rate line 118, which continues until interruption Y is over and the system resumes pumping, marked at Y2 minutes. Again, because the prior art system illustrated is flow-rate driven, the pump resumes its flow rate F ml/min at flow rate line 119 until the conclusion of delivery at time E minutes.
(43) Referring now to chart 120 of
(44) When the pump operates at flow rate F ml/min at 112, the total volume delivered is illustrated on line 140. Upon the start of interruption X at time X1 minutes, the total volume ceases to accumulate 142 because the pump has stopped operating, and only after X2 minutes (and the conclusion of interruption X) does the total volume continue to rise along line 144. It should be appreciated that, because the flow rate 116 is still F ml/min, the slope of 144 is equal to the slope of 140, which is equal to F. Similar to interruption X, the interruption Y at Y1 minutes results an 0 ml of volume accumulating from Y1 to Y2 minutes 146. Following interruption Y, pumping resumes at F ml/min 119 and volume accumulates as expected until the delivery's conclusion at E minutes.
(45) Chart 120 illustrates the deficiency of this prior art system at E minutes. Specifically, it should be appreciated that the difference in total volume delivered C ml vs. total volume prescribed D ml is shown by bracket 150. Because the interruptions stopped the pump, and the subsequent restarts of the pump did not account for the interruptions, D minus C ml 150 of nutrition that should have been delivered was not.
(46) For each of the illustrated embodiments in
(47) Referring now to
(48) To draw an analogous comparison to the
(49) Now referring to the bottom chart 220, the first portion of total volume delivered from the start of delivery to X1 240 is identical to profile 140 of
(50) Similar to interruption X, the interruption Y at Y1 minutes results an 0 ml of volume accumulating from Y1 to Y2 minutes 246. Following interruption Y, pumping resumes at another recalibrated catch-up flow rate and volume accumulates as expected until the delivery's conclusion at E minutes. Because the system was programmed to adjust catch-up flow rate 216 to increase from F ml/min to G ml/min in order to complete the prescribed delivery on time, a second interruption Y will once again affect the total nutrition that will be delivered to the patient, absent another pump recalibration. As seen in upper chart 210, after the conclusion of Y interruption at Y2 minutes, the pump catch-up flow rate is recalibrated again and increased from G ml/min to H ml/min as shown by line 219. To determine just how much the pump need speed up to meet the volume and duration prescription, the flow rate H must be set at the same as the slope of line 248. It should be appreciated that B′ ml of volume has been delivered as of interruption Y, and the slope line 248 can be calculated by subtracting B′ from the total prescribed volume D over the time E minutes minus Y2 minutes.
(51) Assuming the delivery does not experience anymore interruptions, and the flow rate H does not exceed any of the pump's maximum pre-set flow rates as discussed above, this second increased catch-up flow rate will result in the patient receiving the prescribed total volume over the prescribed delivery duration notwithstanding two disruptive interruptions.
(52) Referring now to
(53) After interruption X, and similar to the slope 244 of
(54) The practical result of the maximum flow rate being reached is more easily illustrated in Section IV of
(55) In various embodiments, the system is configured to display to the user or clinician both the proposed catch-up flow rate 348 and the maximum catch-up flow rate 348′, and indicate to the user which of the flow rates is the actual pump operating flow rate. The system of various embodiments is configured to calculate and display on the user interface the amount of nutrition D minus D′ that will not be delivered to the patient, but that was intended for delivery. In one embodiment, the system will determine the percentage of the total volume delivered vs volume prescribed, and display on the user interface what percent of the prescription was achieved. In other embodiments, the user interface will display what percentage has been achieved in real time, as well as what percentage will be achieved according to the current and/or maximum pump flow rates and the duration of delivery remaining. Some embodiments include the calculation of assuming no more interruptions in the calculation or projected prescription delivery percentage. Other embodiments may incorporate external parameters and factors in the calculation of the projected percentage prescription delivered, such as planned interruptions that may be specific to that patient.
(56) In the
(57) TABLE-US-00001 Proposed Max Actual Projected Actual Projected Actual Time Flow rate Flow Rate Flow Rate Volume Volume Percentage Percentage 0 F M F D 0 100% 0% X1 F M 0 D A 100% (D-A/D)% X2 G M G D A 100% (D-A/D)% Y1 G M 0 D B′ 100% (D-B′/D)% Y2 H M M D B′ 100% (D-B′/D)% E M M M D′ D′ (D-D′/D)% (D-D′/D)%
(58) As seen in the table above, the Proposed Flow Rate shows the dynamically adjusting flow rates throughout six different milestones of the delivery: immediately at the start of delivery (0), beginning of interruption X (X1), end of interruption X (X2), beginning of interruption Y (Y1), end of interruption Y (Y2), and end of delivery. At the start of the delivery, the proposed flow rate is the prescribed flow rate until the end of an interruption, X2, at which point the proposed catch-up flow rate is adjusted to G. When a second interruption occurs, the proposed catch-up flow rate becomes H. Column three shows the max flow rate throughout the delivery, which is M. Column four lists the actual flow rate, which, during interruptions is zero, and which adjusts the proposed flow rate based upon any limitations from the max flow rate in column three. It should be appreciated that, since H exceeds M as seen on
(59) Column five shows the projected volume, which matches the prescribed volume D until it becomes evident to the pump that delivering all of the prescription is not feasible within the duration allowed, at which time it becomes D′. Actual volume delivered is shown in column six. It should be appreciated that, subject to the maximum flow rate M requiring the pump operate slower than the proposed flow rate H at Y2, the projected volume never reaches D, and therefore D′ is the final volume of nutrition delivered to the patient. Columns seven and eight show the projected percentage of prescription that will be delivered by the end of feeding and the actual prescription delivered at the various times of the feeding, respectively.
(60) Referring now to
(61) In the event of an over-delivery, whether as a result of a planned interruption or an unplanned interruption, the pump's flow rate is increased to the maximum flow rate M, as in
(62) It should be appreciated that some systems enable the automatic adjustment of an over-delivery flow rate to accommodate future interruptions that are similar to historical ones. The system is capable of storing patient-specific data (either locally or through a known interconnected network and database system). From past deliveries, the system can become ‘smart’ to the specific patient to predict timing, duration, and frequency of potential unplanned interruptions. With such knowledge, or even the knowledge of data from a pool of typical patients (and not that specific patient), the prescriptions, over-delivery flow rates, catch-up flow rates, bolus feeding timings, planned stop durations, and override minimums and maximums can be adjusted proactively to adjust for future interruptions based on historical data.
(63) In various alternative embodiments, an over-delivery flow rate or catch-up flow rate can be adjusted to accommodate for future interruptions similar to historical interruptions experienced during the same discrete continuous or intermittent feeding session. For example, if a feeding is scheduled for four hours and after the first hour, there were 15 minutes of total interruptions, the catch-up flow rate or over-delivery flow rate could be adjusted to not only make up for the 15 minutes of delay, but also to anticipate an additional 45 minutes of delay in the remaining three hours. The rate could be adjusted downward periodically (tapering flow rate) if these additional delays are not realized. It should be appreciated that the pump's incorporation of information into the catch-up flow rate or over-delivery flow rate calculations could be across a period of hours, days, weeks, or months. In some embodiments, the pump is set to accept information from historical data to become smart and in other embodiments the pump is set to be blind and not take into account its environment.
(64) In various embodiments, the tapering flow rate is activated when the total nutrition volume or energy delivered is a certain percentage of the total prescribed nutrition volume or energy. For example, if 90% of the total nutrition volume or energy has been delivered, but only 80% of the duration of the delivery has elapsed, the pump can automatically slow the pump down to a linear or a non-linear tapering flow-rate profile so that the remaining 10% of total nutrition volume or energy is delivered smoothly over the remaining 20% of the prescribed delivery duration. It should be appreciated that, by using a tapering flow-rate profile, whether linear or non-linear, the prescription is still fully delivered as outlined and sudden increases or decreases of pump flow rate are avoided.
(65) Referring again to
(66) In
(67) Returning to
(68) Referring now to
(69) In this particular intermittent delivery system 600, the second delivery (S2 to E2) is also originally prescribed to deliver 500 ml (D″ minus D). Because there was a shortfall of delivery of D minus D1 ml 650 as of the end of the first delivery E1, the system is programmed to remember the shortfall and make up for it in the second delivery. For example, although the second delivery has a prescribed volume of 500 ml, its target flow rate in
(70) It should be appreciated that, if the deliveries of
(71) In various embodiments, some or all of the information portrayed in the table above can be displayed on the user interface for a real-time view of feeding progress (volume and flow rate) and percentage of completion expected and achieved.
(72) In one embodiment, following an interruption (whether planned or unplanned), the pump controller increases the pump flow rate to the maximum allowable flow rate until the delivery is back on track with the planned delivery profile. Referring now to
(73) The controller of this embodiment also calculates a partial time duration completed (T2), a catch-up time duration (T4), and a residual time duration (T5). Similar to the volumes of the profile, the overall time T1 is equal to the sum of: the partial time duration completed (T2), the catch-up time duration (T4), and the residual time duration (T5). Therefore, T1=T2+T4+T5.
(74) In this embodiment, the controller also calculates a proposed delivery flow rate (F2) of the pump based upon a maximum allowable catch-up flow rate restriction, as discussed in other embodiments here. The controller also determines a residual flow rate (F3). In this embodiment, following the interruption, the pump is programmed to automatically ramp to the maximum allowable flow rate immediately, rather than an interim catch-up flow rate calculated as in other embodiments. The pump is operated at the maximum allowable flow rate (F2) until it reaches the original flow profile along the slope of (F1), at which point it is “back on track”. Once the flow profile is back on track, the pump speed is reduced to a residual flow rate (F3), which in one embodiment, is the same as the first delivery flow rate (F1). In an embodiment, the controller calculates the residual flow rate (F3) based upon the residual volume (V5) and the residual time (T5), wherein F3=V5/T5. In various embodiments, the proposed delivery flow rate (F2) is greater than the residual flow rate (F3). In an embodiment, the proposed delivery flow rate (F2) is equal to the maximum allowable catch-up flow rate restriction. In an embodiment, the catch-up time T4=[V1−V2−F1*(T1−T2)]/(F2−F1).
(75) In another embodiment discussed above and illustrated in
(76) Upon resumption of the delivery, the pump's flow rate is increased as illustrated by the slope of line 904 between time R minutes and time S minutes. At S minutes of the delivery, a second interruption occurs 905 for a duration of Y minus S minutes. It should be appreciated that any number of interruptions are contemplated prior to the extended delivery operation embodiment discussed here. At time Y minutes of the delivery, when the interruption has concluded, the pump system calculates that the maximum allowable catch-up flow rate. In the illustrated embodiment, the slope of line 906 represents the maximum allowable catch-up flow rate. At time Y, the pump system recognizes that only B % of the total 100% nutrition has been delivered. The pump system also recognizes that the allotted time for the entire delivery is X minutes. As seen graphically in
(77) Accordingly, in this and other contemplated embodiments, the pump system: (1) calculates at time Y that the maximum allowable catch-up flow rate 906 will not result in 100% nutrition delivery by allotted time X minutes; and (2) calculates a time Z minutes at which point 100% of the nutrition would be delivered with the pump operating under the maximum allowable catch-up flow rate, or any other suitable flowrate programmed by the clinician. Upon calculation of required delivery extension time Z minutes, the pump system of various embodiments provides the option to the patient or clinician to extend the delivery by the required duration of Z minus X minutes in order to deliver the full 100% of the nutrition to the patient.
(78) Various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.