NZ620431B2 - Infusion pump with independently controllable valves for optional gravity infusion and low power operation - Google Patents

Abstract

Disclosed is an infusion pump (100) for controlling a flow condition of a source of fluid (106) and delivered to a user through an output tubing (108). The pump comprises a computer processor (102), a first actuator (118), a second actuator (126) and an outlet valve (116). The first actuator (118) is configured for displacing at least one finger for compressing a first portion of the output tubing (108) to deliver the source of fluid (106) to the user. The second actuator (126) is configured for selectively operating an inlet valve of the infusion pump (100) to control the flow condition of the source of fluid (106) to the first portion of the output tubing (108). The outlet valve (116) is disposed downstream of the first portion of the output tubing (108), and the output tubing (108) includes a second portion between the inlet and outlet valve (116). The outlet valve (116) is controlled by the first actuator (118). The first actuator (118) controls the displacement of the at least one finger and the operation of the outlet valve (116) independently from the inlet valve. The second actuator (126) controls the operation of the inlet valve independently from the at least one finger. s configured for displacing at least one finger for compressing a first portion of the output tubing (108) to deliver the source of fluid (106) to the user. The second actuator (126) is configured for selectively operating an inlet valve of the infusion pump (100) to control the flow condition of the source of fluid (106) to the first portion of the output tubing (108). The outlet valve (116) is disposed downstream of the first portion of the output tubing (108), and the output tubing (108) includes a second portion between the inlet and outlet valve (116). The outlet valve (116) is controlled by the first actuator (118). The first actuator (118) controls the displacement of the at least one finger and the operation of the outlet valve (116) independently from the inlet valve. The second actuator (126) controls the operation of the inlet valve independently from the at least one finger.

Description

INFUSION PUMP WITH INDEPENDENTLY CONTROLLABLE VALVES FOR OPTIONAL GRAVITY INFUSION AND LOW POWER OPERATION CAL FIELD The present disclosure relates to an on pump with an independently controllable inlet valve. The present disclosure also relates to an infusion pump with an inlet valve for controlling flow from a drip chamber. The present disclosure further relates to an infusion pump switchable between gravity-feed operation and active pumping operation.

BACKGROUND Figure 9 is a schematic representation of prior art peristaltic pump 10. Pump includes drip r 12 connected to source of fluid 14, tubing 16 connected to the drip chamber, upstream valve 18 to block or allow fluid flow from the drip chamber to the tubing, and a plurality of s 20 to create a moving zone of occlusion along the tubing and to push the fluid downstream past downstream valve 22. The ream valve is used to block or enable fluid output, for example, blocking fluid output when the upstream valve is opened. The upstream valve, s and downstream valves are typically engaged with cam lobes 24 on cam shaft 26 and rotated by motor and associated gears 28. Different shapes for the cam lobes determine the timing of opening and g of the upstream and downstream valves and peristaltic function of the fingers. In l a pumping cycle for the pump is as follows: a first cam lobe operates the upstream valve to fully open the upstream valve to admit a volume of fluid while a second cam lobe operates the outlet valve to close the downstream valve; the first cam lobe operates to close the inlet valve and the second cam lobe operates to fully open the downstream valve; a set of cam lobes operates on the fingers such that the fingers expel fluid past the downstream valve; the second cam lobe es on the downstream valve to close the downstream valve; and, the preceding sequence is repeated. not possible to l the amount of fluid entering the chamber, independently from the nts of the . That is, for each pump cycle, the upstream valve is fiilly opened and an amount of fluid equal to the maximum volume flows to the tubing from the drip chamber. Therefore, the m amount of fluid entering the pumping chamber at each pumping cycle is 0.080 milliliter in this case.

Certain infusion regimens require very low flow rates, for e, 0.1 microliter/hour. Pump 10 has difficulty in maintaining flow continuity at such low flow rates.

Cam shaft 26 is supported proximate each end by respective bearings 30. The bearings hold the shaft in a position that is fixed except for on of the shaft. The fixed position is such that cam lobes 24 are able to operate fingers 14 and to open and close the upstream and ream valves. In general, the cam lobes are positioned such that one of the upstream or downstream valves is closed at all times. One possible mode of failure for pump 10 is the failure of some or all of bearings 30. For example, the bearings can fail such that the shaft is no longer held in the fixed position noted above and one or both of the ends of the shaft are further from body. In this case, the cam lobes may be far enough from the fingers and/or the upstream or ream valves such that the cam lobes are no longer able to close the upstream and/or downstream valves. Thus, for e of some or all of the bearings, pump 10 is unable to control flow from the drip chamber. For example, in the sequence noted above, when the upstream valve is opened it is presumed that the downstream valve is closed. However, if the g failure results in the cam shaft being unable to close the downstream valve, an uncontrolled flow from the drip chamber results when the upstream valve is opened. An uncontrolled flow condition can be extremely hazardous to a patient receiving an infusion via pump 10, for example, resulting in a dangerously high dosage of a drug being infused with pump 10.

[0006] Figure 10 is a schematic representation of a prior art gravity—feed infusion arrangement. In some clinical applications, fluid ry by gravity, as shown in Figure 10, is acceptable. For delivery by gravity, gravity force is strong enough to cause fluid to flow from container 32 hung on pole 34 through tubing 36 to the patient. However, the flow rate from container 32 cannot be automatically controlled and it is difficult to accurately control the flow rate. For example, roller clamp 38 is used to manually control the flow. The clamp is equipped with roller 40 that may be rolled by hand to contract tubing 14 to compress the tubing to control the flow h the tubing from container 32. Such manual control is not accurate and is very susceptible to human error.

It is an object of the present invention, to at least provide the public with a useful choice.

According to one aspect of the invention, there is provided an infusion pump, including: a computer processor; a first actuator configured for displacing at least one finger for compressing a first n of the output tubing to deliver the source of fluid to the user; a second actuator configured for selectively operating an inlet valve of the infusion pump to control the flow ion of the source of fluid to the first portion of the output tubing; and an outlet valve is disposed downstream of the first portion of the output tubing, and the output tubing includes a second portion between the inlet and outlet valves, said outlet valve being controlled by said first actuator, wherein, using the processor, the first actuator controls the displacement of the at least one finger and the operation of said outlet valve independently from the inlet valve, and the second actuator controls the operation of the inlet valve ndently from the at least one finger.

Unless the context clearly requires otherwise, throughout the description and claims the terms “comprise”, “comprising” and the like are to be construed in an inclusive sense, as opposed to an exclusive or tive sense. That is, in the sense of “including, but not limited to”.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Various embodiments are disclosed, by way of e only, with nce to the accompanying tic drawings in which corresponding reference symbols indicate corresponding parts, in which: Figure 1 is a schematic representation of an infusion pump with independent control of inlet and outlet valves; Figures 2A through 2G are schematic diagrams illustrating a pumping cycle for the pump shown in Figure 1; is a graph showing flow pulses for the pump shown in is a table showing example flow pulses and fluid volumes at a flow rate of 0.1 microliter/hour; is a pictorial representation of a portion of the pump shown in showing a cam shaft bearing; is a perspective view of an exemplary embodiment of an on pump with independent control of inlet and outlet valves and low power operation; is a detail of a portion of the pump shown in is a schematic entation of an infusion pump for use in gravity-feed mode; is a schematic entation of a prior art altic pump; and, is a schematic representation of a prior art gravity-feed infusion arrangement.

DETAILED DESCRIPTION At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the disclosure. It is to be understood that the disclosure as claimed is not limited to the disclosed aspects.

Furthermore, it is understood that this sure is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also tood that the terminology used herein is for the purpose of describing ular aspects only, and is not intended to limit the scope of the present disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. It should be understood that any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure.

Figure 1 is a schematic representation of on pump 100 with independent control of inlet an outlet valves. Pump 100 includes specially programmed microprocessor 102, drip chamber 104 for connection to source 106 of fluid and to output tubing 108. The pump includes flow sensor, or flow meter, 110 for measuring flow through the drip chamber, and pumping section 112 including a plurality of fingers 114, outlet valve, or downstream valve, 116, and actuator 118. The pumping section is not limited to a particular number of s 114.

Actuator 118 is controllable using the microprocessor, to rotate cam shaft 119 and cam lobes 120 such that the cam lobes contact the plurality of fingers to tially displace the plurality of finger to compress n 121 of the output tubing t a support structure, such as supporting platen 122, to ce fluid from the drip chamber through the output tubing and past the outlet valve. Portion 121 also can be considered the portion of the tubing between the inlet and outlet . Shaft 119 and cam lobes 120 can displace the fingers n any manner known in the art. Rotation of shaft 119 and cam lobes 120 also controls opening and closing of valve 116.

[0013] The pump also includes inlet valve, or upstream valve, 124 disposed between the drip chamber and the pumping section, and actuator 126, controllable using the microprocessor. Actuator 126 is arranged to operate the inlet valve, for example, open or close the inlet valve, or position the inlet valve between open and closed positions, independent of the displacement of the plurality of fingers; or to operate the inlet valve, for e, to position the inlet valve between an open or closed position, to control a rate of flow of fluid from the drip chamber to the output tubing, as further described below.

Figures 2A h 2G are schematic diagrams rating a pumping cycle for pump 100 shown in Figure 1. The following should be viewed in light of Figures 1 through 2G.

Pump 100 enables execution of extremely low continuous flow rates. For example, pump 100 is compliant with the ECRI Institute's Excellent rating for flow continuity at low flow rates, which requires that a period of no flow in an infusion regimen to be less than 20 seconds. In an e ment, the specially programmed microprocessor is for implementing the ing example on scheme, which can be a low flow rate regimen. As shown in Figure 2A, at the start of a pump cycle for the infusion n, the microprocessor controls actuator 126 to close the inlet valve and controls actuator 118 to close the outlet valve and to move the fingers for maximum compression of the tubing by the fingers. As shown in Figure 2B, actuator 118 ts the fingers, while the valves remain closed, to create a vacuum in portion 121 of the output tubing, that is, in the passageway formed by portion 121.

As shown in Figure 2C, the microprocessor controls actuator 126 to displace the inlet valve to flow a specified volume of fluid, as measured by sensor 110, from the drip chamber to portion 121 of the output . By specified volume, we mean a ular volume that is inputted to the microprocessor, stored in memory 128 of the microprocessor, or calculated by the microprocessor. In general, the specified volume is associated with a desired fluid flow to achieve the d outcome of the infusion scheme. Sensor 110 monitors flow through the drip chamber to portion 121 of the tubing. In an example embodiment, the inlet valve is continuously positionable between a fully closed position and fully open position. For example, a position of the inlet valve is not limited to a series of stepped positions, which would be the case if actuator 126 were a stepper motor. Such continuous positioning greatly increases the accuracy and range of flow rates, from the drip chamber to portion 121, executable using the inlet valve.

As shown in Figure 2D, after the specified volume of fluid has flowed through the drip chamber to portion 121 of the tubing, for example, as measured by sensor 110, the microprocessor controls actuator 126 to close the inlet valve. As shown in Figure 2E, the microprocessor then controls actuator 118 to operate the outlet valve, for example, fully opening the outlet valve. As shown in Figure 2F, the microprocessor controls actuator 118 to displace the plurality of fingers to expel the specified volume of fluid past the outlet valve within a first specified time period. By specified time period, we mean a particular time period that is inputted to the microprocessor, stored in memory by the microprocessor, or calculated by the microprocessor. In general, the specified time period is associated with a d outcome of the infusion scheme or required operation of the pump. For example, the specified time period can be associated with the ECRI Institute's Excellent rating for flow continuity at low flow rates. As is understood in the art, a time period for infusing the specified volume is usually associated with the specified , this time period can be the first specified time period noted above. At the end of the first specified time period, as shown in Figure 2G, the microprocessor controls actuator 118 to close the outlet valve, ting the pumping cycle.

As noted below, the cycle described above is typically repeated at a ular frequency to attain a d flow rate over a longer time period.

In an example embodiment, tubing 108 is compressed between the fingers and the supporting platen so that the tubing is partially compressed, reducing the maximum amount noted above, which in turn reduce the volume of fluid entering portion 121 each time the inlet valve is opened. In an example embodiment, tubing 108 has an inner diameter of about 0.1'' length L for portion 122 of the tubing (between the inlet and outlet ) is around 1.25.'' This configuration s in a maximum volume of about 0.160 milliliter for portion 121. In the example that follows, the maximum volume is reduced to about 0.080 milliliter.

Figure 3 is a graph showing e flow pulses for pump 100 shown in Figure 1.

[0020] Figure 4 is a table showing example flow pulses and fluid volumes at a flow rate of 0.1 microliter/hour. The ing should be viewed in light of Figures 1 through 4. The unit of measurement for the x axis of the graph is second, and the unit of measure for the y axis is microliter of fluid from source 106. The ECRI's Excellent ranking for flow continuity at low flow rate es that the period of no flow is less than 20 s. For example, the time period between Figures 2A and 2F must be less than 20 seconds. The microprocessor controls actuator 126 to displace the inlet valve to generate flow pulse 130, that is, to flow a specified volume of fluid from the drip chamber to n 121 of the output tubing.

Flow pulses 130A and B are shown in Figure 3. As an example, such pulses are generated in the portion of a pumping cycle shown in Figure 2C. In Figure 3, the pulses are sized and spaced to implement a flow of 0.1 microliter/hr. It should be understood that other flow pulses are possible, for example, as shown in Figure 4.

As shown in Figures 3 and 4, a variety of pulses 128 can be generated to ent the pumping cycle shown in Figures 2A through 2G. For e, pulse 130A is about two second long and the subsequent expelling of fluid from portion 121 is done in about 18 s. As another example, pulse 130B is about 10 seconds long and the uent expelling of fluid from portion 121 is done in about 10 seconds. Thus, to generate a rate of 0.1 microliter/hr with pulses 130A, pump 100 delivers pulses 130A (Figures 2F and 2G) about 164 times per hour, and each pulse delivers about 0.61 microliter of fluid. To generate a rate of 0.1 microliter/hr with pulses 130B, pump 100 delivers pulses 130B (Figures 2F and 2G) about 120 times per hour, and each pulse delivers about 0.83 iter of fluid. It should be understood that combinations of different pulse widths, for example, combinations of pulses shown in Figure 4, can be used during an infusion regimen. Other combinations of number of pulses and flow pulses are also possible to achieve the desirable flow rate and a no-flow period of less than 20 seconds. For example, for flow rate of 0.1 milliliter/hr or 100 microliter/hr, it is possible to have 10 flow pulses per hour, each of which has 10 microliter of fluid and delivered into the section 121 in less than 20 seconds. The fluid then can be expelled in 5 minutes and 40 seconds.

To provide better flow continuity at low flow rates, the amount of fluid entering portion 121 of the tubing is made smaller than the total volume available in portion 121. For example, when the total volume available is 0.080 milliliter, the amount of fluid entering portion 121, for e, pulses 130, is much less than the ble volume, as shown in Figure 4. g such vely small amount of fluid can only be done if flow into portion 121 is controlled separately from the movement of the fingers in the pumping chamber, as described above and shown in Figures 2A through 2G. Shaft 119 revolves once during the pumping cycle shown in FIGS. 2A-2G. For example, to implement an infusion n of 0.1 microliter/hour, shaft 119 revolves once about every 6 minutes.

Using pulses 130A and with a maximum volume available for portion 121 equal to 0.80 iter, the amount of fluid entering portion 121 in each pumping cycle is no more that 0.7 percent of the maximum volume for portion 121. Using pulses 130A and with a maximum volume available for portion 121 equal to 0.80 milliliter, the period of no flow for pulses 128A is about 2 seconds or about 10 t of the maximum no flow period of less than 20 seconds needed for compliance with the ECRI's Excellent ranking for flow continuity at low flow rate. It should be understood that pump 100 is not limited to this ratio of fluid entering portion 121 and maximum volume of portion 121, and that other ratios are possible, for example, as shown in Figure 4

[0024] In contrast, as noted supra, since for a typical prior art peristaltic pump, valves and s are all mounted on a single cam shaft, it is not possible to control the amount of fluid entering the r independently from the movements of the fingers. Therefore, with a reduced volume of 0.080 milliliter for the output tubing, to generate 0.1 microliter/hr, the output tubing for the prior art pump has to be pumped out in one cycle over a period of 48 min with the attendant problems noted above.

A pumping sequence for an infusion scheme, such as shown in Figures 2A through 2G, can be implemented in a periodic sequence, for example, ing the pumping sequence shown in Figures 2A h 2G, to control flow through the drip chamber. For example, a particular flow rate, such as 0.1 microliter/hr, can be executed by repeating the pumping sequence shown in s 2A through 2G.

Flow sensor 110 in conjunction with actuators 118 and 126 enable redundant shut-off of flow from the drip chamber, for example, in the event of a high flow event. In one embodiment, threshold value 132 for flow detected by sensor 110 is stored in memory element 128. This value can be fixed or can be dependent upon the flow rate for a particular infusion n being implemented by the pump, for example, value 132 could be a percentage of the flow rate. The microprocessor uses value 132 for determining if a high flow event is occurring and responds accordingly. For example, for detection, by the flow sensor, of flow above a predetermined level, such as value 132, the rocessor is for using actuator 118 to close the outlet valve independently of the inlet valve and/or using or 126 to close the inlet valve ndently of the outlet valve. Thus, even if one or the other of actuators 118 or 126 fails, flow from the drip chamber and portion 121 can be blocked. Value 132 can be received by the microprocessor as input or can be calculated by the microprocessor.

Figure 5 is a pictorial representation of pump 100 shown in Figure 1 showing cam shaft bearing 134. The ing should be viewed in light of Figures 1 and 5. Cam shaft 119 is supported proximate each end by respective gs, for example, bearing 134 at the downstream end of the shaft. The bearings hold the shaft in a position that is fixed except for rotation of the shaft. That is, the bearing fix the shaft while enabling rotation of the shaft, for example, to position cam lobes 120A and 120B to operate outlet valve 116 and fingers 114, respectively.

As noted supra, one possible mode of failure for a pump with a cam shaft is the failure of the bearings for the cam shaft. For example, as shown in Figure 5, if bearing 134 fails, end 136 can shift in direction D, away from the main portion of the pump. One result of the shifting of end 136 is that cam lobes 120 may be displaced far enough from the s and the outlet valve such that the cam lobes are no longer able to close the outlet valve or the fingers are no longer able to fully compress portion 121 of the tubing. However, since valve 124 is controlled separately from cam shaft 119 via actuator 126, valve 124 can be actuated to block the tubing regardless of the status of the cam shaft. Thus, even though failure of one or both of the gs may render fingers 114 and valve 116 unable to l or block flow through the tubing, independently actuated valve 124 is still able to provide flow blockage to prevent a hazardous uncontrolled flow condition.

[0029] Pump 100 also provides energy savings. In an example ment, pump 100 is switchable between a gravity-feed mode and an active pumping mode. For example, the default mode of operation is the gravity-feed mode and pump 100 operates in this mode unless inadequate flow is detected as described below. The microprocessor operates actuator 118 to maintain the plurality of fingers in respective fixed positions and to open the outlet valve such that a passageway is formed in the output tubing between the inlet and outlet . For example, the fingers are displaced so as to compress the tubing to a n specified extent (partially closing the passageway h portion 121) or are displaced such that the passageway is fully open. The actual location of the fingers and the resultant volume for the passageway can be ined ing to the infusion regimen being implemented by pump 100.

The microprocessor controls actuator 126, for e, using feed back from the flow sensor, to e the inlet valve to establish flow from the drip chamber to the output tubing at a desired flow rate. By desire flow rate, we mean a ular flow rate that is inputted to the microprocessor, stored in memory 128 of the microprocessor, or calculated by the rocessor. In general, the desired flow rate is associated with a desired outcome of the infusion scheme. As an example, for a particular drug being infused via the infusion scheme, a particular flow rate is needed to attain a desired therapeutic affect.

In an example embodiment, as long as gravity force is sufficient to provide the desire flow rate, the gravity-feed mode is used. For example, as long operation of the input valve is able to provide the desired flow rate, the pump es in the gravity-feed mode. If operation in the gravity-feed mode is not able to provide the desired flow rate, the pump automatically switches to the active pumping mode. For example, if the inlet valve is fully open and the flow sensor measures flow less than a threshold related to the desired flow rate, for example, a specified percentage of the flow rate, the microprocessor switches to the active g mode.

In general, the active pumping mode includes nated operation of the inlet and outlet valves and the s to introduce fluid into portion 121 and expel the fluid past the outlet valve. The pumping cycle shown in Figures 2A through 2G is an example, of operation in the active pumping mode. It should be understood that the active pumping mode is not limited to the pumping cycle shown in Figures 2A through 2G.

[0032] Figure 6 is a perspective view of an exemplary embodiment of on pump 100 with independent control of inlet and outlet valves and low power operation.

Figure 7 is a detail of a portion of pump 100 shown in Figure 6. The following should be viewed in light of Figures 6 and 7. s 6 and 7 depict an exemplary construction of at least portions of a pump with ndent control of inlet and outlet valves and other functions described supra. It should be understood that a pump with independent control of inlet and outlet valves and other functions described supra is not limited to the configuration shown in Figures 6 and 7.

Figure 8 is a schematic representation of infusion pump 200 for use in gravityfeed mode. Pump 200 includes specially programmed microprocessor 102 and drip r 104 for connection to source 106 of fluid and to output tubing 108. In one embodiment, the source of fluid is a medication bag. In one embodiment, element 107 is used to force fluid from source 106, for example, to squeeze a medication bag, to force fluid out of source 106 and to the drip chamber. For example, in the event that gravitational force on the fluid in source 106 is not sufficient to overcome backpressure in tubing 108, for example, due to a patient to whom the tubing is connected, t 107 can be used to provide the extra force needed to overcome the back pressure. Any device known in the art can be used for element 107.

[0035] The pump includes flow sensor, or flow meter, 110 for measuring flow through the drip chamber, and inlet valve 124 ed downstream of the drip chamber. Actuator 126 is llable using the microprocessor to regulate flow through tubing 108. Actuator 126 is arranged to operate the inlet valve, for example, open or close the inlet valve, or position the inlet valve n open and closed positions, to control a rate of flow of fluid from the drip chamber to the output tubing. Thus, pump 200 is configured to e in gravity-feed mode, for example, pump 200 does not include a pumping section, such as pumping section 112 for pump 100 in Figure 1, to ly transport fluid from source 106 through tubing 108. In the gravity-feed mode, the flow can be via gravitation force alone or can be via a combination of gravitation force and force applied by element 107.

[0036] In gravity-feed mode, the rocessor is arranged to control the actuator, using data from the flow sensor including flow measured by the flow sensor, to operate the inlet valve to establish flow from the drip chamber to the output tubing at a desired flow rate. That is, the microprocessor accepts data 202 from the flow sensor including flow measured by the flow sensor and controls, using the data, the actuator to operate the inlet valve to establish flow from the drip chamber h the output tubing at a desired flow rate. The discussion for pump 100 regarding a desired flow rate is applicable to Figure 8 and pump 200. Pump 200 is arranged to occlude the tubing, via valve 124, in response to emergency or alarm conditions.

Although pumps 100 and 200 have been shown with a particular uration of components, it should be understood that pumps 100 and 200 are not limited to the particular configuration of components shown and that other configurations of components are possible.

It will be iated that various of the above-disclosed and other features and functions, or atives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those d in the art which are also intended to be encompassed by the following claims.

Claims (22)

1. An infusion pump for controlling a flow condition of a source of fluid and delivered to a user h an output tubing, the pump comprising: a computer processor; a first actuator configured for cing at least one finger for compressing a first portion of the output tubing to deliver the source of fluid to the user; a second actuator configured for selectively operating an inlet valve of the infusion pump to control the flow condition of the source of fluid to the first portion of the output tubing; and an outlet valve is disposed downstream of the first portion of the output tubing, and the output tubing includes a second portion between the inlet and outlet valves, said outlet valve being lled by said first actuator, wherein, using the processor, the first actuator controls the displacement of the at least one finger and the operation of said outlet valve independently from the inlet valve, and the second actuator controls the operation of the inlet valve independently from the at least one finger.

2. The infusion pump of claim 1, wherein the source of fluid is ted to a drip chamber, the inlet valve is disposed between the drip chamber and the first portion of the output tubing, and is arranged for compressing the output tubing to control the flow condition of the source of fluid through the output .

3. The infusion pump of claim 1, wherein said fingers are constructed and arranged to te a pumping action by compressing the first portion of the outlet tubing.

4. The infusion pump of claim 1, wherein the source of fluid is connected to a drip chamber, the second actuator operates the inlet valve for enabling flow of a predetermined amount of the source of fluid from the drip chamber to the second n of the output tubing while controlling the first actuator to close the outlet valve, and maintaining the at least one finger in a respective fixed position.

5. The infusion pump of claim 1, wherein the source of fluid is connected to a drip chamber, the second actuator es the inlet valve for disabling flow of the source of fluid from the drip chamber to the second portion of the output tubing after a predetermined amount of the source of fluid has flowed to the second n of the output tubing.

6. The infusion pump of claim 1, wherein the first actuator operates the outlet valve for displacing the at least one finger to expel a predetermined amount of the source of fluid past the outlet valve within a first specified time period, and to close the outlet valve at the end of the first specified time period.

7. The infusion pump of claim 1, further comprising a flow sensor configured for measuring a flow rate of the source of fluid, and memory ured for storing a threshold value of the flow rate, wherein the inlet valve is operated based on the old value.

8. The infusion pump of claim 7, wherein the inlet valve is operated based on the flow rate independently from the outlet valve, and the outlet valve is operated based on the flow rate independently from the inlet valve.

9. The infusion pump of claim 1, wherein the infusion pump operates in at least one of: a gravity-feed mode and an active g mode based on a flow rate of the source of fluid.

10. The infusion pump of claim 1, wherein a pumping section of the pump includes an outlet valve, and the pumping section with the at least one finger is configured for acting on the first n of the output tubing located between the inlet valve and the outlet valve, using a common linkage for controlling the at least one finger and the outlet valve.

11. A computer-implemented method for controlling a flow condition of a source of fluid and delivered to a user through an output tubing, the method comprising: displacing at least one finger for compressing a first portion of the output tubing to deliver the source of fluid to the user using a first actuator; selectively operating an inlet valve of the on pump to l the flow condition of the source of fluid to the first portion of the output tubing using a second actuator; disposing an outlet valve downstream of the first portion of the output tubing, and including a second n of the output tubing between the inlet and outlet valves; controlling, using a computer processor, the displacement of the at least one finger and the outlet valve independently from the inlet valve using the first actuator; and controlling, using the er processor, the operation of the inlet valve independently from the at least one finger and the outlet valve using the second actuator.

12. The method of claim 11, further comprising disposing the inlet valve between a drip chamber connected to the source of fluid and the first portion of the output tubing, and arranging the inlet valve for compressing the output tubing to control the flow condition of the source of fluid through the output tubing.

13. The method of claim 11, further comprising operating said fingers to create a pumping action by partially compressing the first portion of output tubing, and operating said first and second valves to periodically block the first portion of output tubing under the control of the processor.

14. The method of claim 11, further sing operating, using the second actuator, the inlet valve for enabling flow of a predetermined amount of the source of fluid from a drip r connected to the source of fluid to the second portion of the output tubing while controlling the first actuator to close the outlet valve, and maintaining the at least one finger in a respective fixed position.

15. The method of claim 11, further comprising operating, using the second actuator, the inlet valve for disabling flow of the source of fluid from a drip chamber connected to the source of fluid to the second portion of the output tubing after a predetermined amount of the source of fluid has flowed to the second n of the output tubing.

16. The method of claim 11, r comprising operating, using the first actuator, the outlet valve for displacing the at least one finger to expel a predetermined amount of the source of fluid past the outlet valve within a first specified time period, and to close the outlet valve at the end of the first specified time period.

17. The method of claim 11, further comprising measuring, using a flow sensor, a flow rate of the source of fluid, and g a threshold value of the flow rate in memory, and operating the inlet valve based on the threshold value.

18. The method of claim 17, further comprising operating the inlet valve based on the flow rate independently from the outlet valve, and operating the outlet valve based on the flow rate independently from the inlet valve.

19. The method of claim 11, r comprising operating the infusion pump in at least one of: a gravity-feed mode and an active pumping mode based on a flow rate of the source of fluid.

20. The method of claim 11, further comprising providing a pumping n having an outlet valve, wherein the pumping section with the at least one finger is configured for acting on the first portion of the output tubing located n the inlet valve and the outlet valve.

21. An infusion pump for controlling a flow condition of a source of fluid and delivered to a user through an output tubing substantially as herein described with reference to any one of the embodiments illustrated in the accompanying gs.

22. A computer-implemented method for controlling a flow condition of a source of fluid and delivered to a user through an output tubing substantially as herein described with reference to any one of the embodiments illustrated in the accompanying drawings.