Multiple medication IV pump

The multiple medication IV pump provides automated intravenous delivery of one or more medications. A carousel assembly holds multiple medication vials, and a computerized control circuit operates the carousel to position a selected medication vial proximate to a spiking unit and mixing chamber to deliver the contents of the vial into an IV solution. The spiking unit and mixing chamber comprise a hollow chamber and a hollow spike, or needle, extending from the hollow chamber. The contents of a medication vial spiked onto the spiking unit flow into the mixing chamber. A fluid entry port located near the top of the mixing chamber is connected to a first pump such that a fluid may be pumped into the mixing chamber. A fluid exit port located near the bottom of the mixing chamber is connected to a second pump such that a fluid may be pumped out from the mixing chamber.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus for delivery of intravenous medications. More particularly, the present invention is a multiple medication IV pump for automated delivery of a medication from one of several medication vials stored within the multiple medication IV pump.

2. Description of the Related Art

Intravenous (IV) delivery of fluids to a patient is commonplace in medical settings, ranging from the injection of a medication with a hypodermic syringe to the infusion of fluids, medications, and nutritional supplements by a pump.

An IV infusion pump is typically used when it is necessary to give a fluid, such as a medication or a nutritional supplement, at a controlled rate over a relatively long time period. An IV line, or catheter, is placed into one of the patient's veins, and connected by a length of tubing to the IV infusion pump, which is, in turn, connected to an IV bag containing the fluid to be supplied.

In contrast to the controlled delivery of a fluid over a relatively long period of time, some medications are administered as a bolus injection, pushing a prescribed amount of the medication into the patient at once. A bolus injection may be made by injecting the medication, with a hypodermic syringe, directly into the patient's vein or body. Preferably, a medication is injected into an IV line that is placed in one of the patient's veins. Generally, administration of a medication into an IV line is followed by a flush of saline solution to ensure that all of the medication has been pushed into the patient. It is common to place an IV line for the purpose of administering bolus injections, such as when multiple intravenous injections may be required or a medication may need to be quickly administered intravenously, so that it is undesirable to spend time to locate a suitable vein for injection.

It is sometimes necessary to deliver multiple medications, or multiple doses of a single medication, over a relatively short time period. One example is in cardiac care, such as in response to a cardiac arrest. Advanced Cardiac Life Support protocols recommend various medications during the course of treating cardiac emergencies. In certain situations, bolus administration of a medication is repeated during the course of treatment until a desired outcome is achieved. In other situations, bolus administration of multiple medications may be given in sequence. In still other situations, bolus administration of one or more doses of one or more medications may be given along with, or followed by, a slow or drip infusion of a medication.

Automated delivery of a sequence of medications would save time, and could help to reduce mistakes in an emergency situation. While an IV pump is useful in delivering a medication, such pumps are typically limited to delivering a slow infusion of a single, or a limited number of, medications. While IV pumps are known to utilize multiple medication channels, and to employ a cartridge system allowing quick exchange or replacement of a medication-containing cartridge, the ability of an IV pump to load itself with a medication automatically from a self-contained medication supply, or to select proper medications for delivery according to a predefined protocol, is largely unknown.

Thus, a multiple medication IV pump solving the aforementioned problems is desired.

SUMMARY OF THE INVENTION

The multiple medication IV pump provides automated intravenous delivery of one or more medications. A carousel assembly within the multiple medication IV pump holds multiple medication vials, and a computerized control circuit operates the carousel to select a given medication, position the medication proximate to a spiking unit and mixing chamber, and deliver the contents of the medication vial into an IV solution stream.

The spiking unit and mixing chamber comprise a hollow chamber and a hollow spike, or needle, extending from the hollow chamber. The spike is adapted for insertion into a medication vial so that the contents of the medication vial flow into the mixing chamber. A fluid entry port located near the top of the mixing chamber is connected by a fluid conduit to a pump so that a fluid may be pumped into the mixing chamber. A fluid exit port located near the bottom of the mixing chamber is connected by a fluid conduit to a pump so that a fluid may be pumped out from the mixing chamber.

The carousel comprises a central hub, from which extends a plurality of track arms adapted to hold multiple medication vials. The carousel rotates to position a selected one of the track arms proximate to the spiking unit. Each track arm has a movable track disposed about the perimeter of the track arm, the track having a plurality of medication vial holders. As the track moves about the perimeter of the track arm, medication vials held in the medication vial holders are moved. Thus, by selecting a given track arm to be rotated into position proximate to the spiking unit, and then by rotating the track arm's track to position a medication vial holder in alignment above the spiking unit, a selected medication vial (or vial holder position) is brought into alignment with the spiking unit to allow delivery of the medication into the mixing chamber.

A vial-handling arm is associated with each track arm. Each vial-handling arm is adapted to grasp a medication vial from a vial holder of the track, and spike the medication vial onto the spiking unit. Each vial handling arm is further adapted to remove an empty vial from the spiking unit and to drop the vial for disposal.

A control circuit, including a display and keypad, allow for selection of a single medication, or a series or protocol of medications, to be automatically administered to a patient through an IV line in connection with the multiple medication IV pump.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is multiple medication IV pump, designated generally as10in the drawings. Referring toFIGS. 1A,1B, and2, the multiple medication IV pump10provides automated intravenous delivery of one or more bolus medications. Medication vials for multiple medications are contained within the multiple medication IV pump10. A control circuit32allows a user to select a medication, or a series of medications, for intravenous delivery through an IV line12to a patient. The medications are delivered along with a fluid solution, such as a normal saline solution, used to flush the medication through the IV line12, or to dilute the medication for correct administration.

The multiple medication IV pump10comprises an exterior housing14having a top shell16and a bottom shell26. The top shell comprises a cylindrical outer wall18and a top20, while the bottom shell26comprises a cylindrical outer wall28and a bottom30. The cylindrical outer wall18of the top shell16comprises a hinged and movable front half22and a fixed rear half24, so that the front half22may be opened for access into the interior of the housing14. In the illustrated embodiment, the top shell16is removable from the bottom shell26, and the top20of the top shell16is hinged, the top20being secured to the top shell16by a hinge21. A lock19secures the top20in a closed position. A disposal chute31is disposed in the bottom shell26for removal of spent medication vials40through the bottom30of the housing14. A receptacle may be located below an outlet of the disposal chute31for collection of the spent medication vials40.

The multiple medication IV pump10is supported by a telescoping pole15mounted to the housing14. The telescoping pole15has a plurality of legs25attached to the lower end of the pole15. Coasters23may be provided at the ends of the legs to prevent the support legs from marring the floor or other supporting surface. A pair of horizontal support arms17is attached to the top of the telescoping support pole15. Each support arm17is provided with a hook at the free end adapted for holding an IV bag50. The support arms17are pivotally attached to the top of the telescoping pole15so that they can be rotated together in the horizontal plane to form a carrying handle for lifting the multiple medication IV pump10during transport.

The control circuit32, comprising a display34and keypad36, is disposed on the housing14for operation of the multiple medication IV pump10by a user. In the illustrated embodiment, the display34and keypad36are located on a front exterior surface of the bottom shell26, although other configurations are suitable.

Within the housing14is a carousel assembly38, adapted to hold a plurality of medication vials40or cartridges, and a spiking unit42and mixing chamber44, adapted to receive a medication vial40and introduce the contents of the medication vial40into a fluid stream within the IV line12. The carousel assembly38, under control of the control circuit32, positions a selected medication vial40in a position proximate to the spiking unit42, and spikes the medication vial40onto the spiking unit42so that the contents of the medication vial40enter into the mixing chamber44.

The spiking unit42and mixing chamber44allow for the introduction of a medication, from one of the medication vials40, into a fluid stream for intravenous delivery to a patient. The multiple medication IV pump10has a first pump46, located within the housing14, that delivers a fluid, such as a normal saline solution, from an IV bag50or a similar source into the mixing chamber44, via a length of IV tubing52. A second pump48, also located within the housing14, pumps the fluid and a medication from the mixing chamber44through the IV line12to the patient. Each of the pumps46,48is in electrical communication with, and is controlled by, the control circuit32. Referring toFIG. 3, the pumps46,48are shown alternatively mounted along with the spiking unit42and mixing chamber44, on an inner surface29of the cylindrical outer wall28. The pumps46,48and the spiking unit42and mixing chamber44may be collected on a removable portion of the cylindrical outer wall28, such as a hinged front panel portion, to allow for periodic removal and replacement of these components.

Returning toFIG. 2, the carousel assembly38of the illustrated embodiment comprises a rotating central hub54and a plurality of arm assemblies56extending radially from the hub54. A hub motor58functions to rotate the central hub54, under the control of the control circuit32. The hub motor58may be engaged with the hub54in a direct-drive configuration, or by a drive train such as the belt drive60shown. The hub motor58may be a stepping motor or another type of motor adapted for accurate positional control, such that the hub54may be rotated into a precise position to bring an arm assembly56into alignment with the spiking unit42. Alternatively, positional control of the hub54may be achieved by use of appropriate positional markers and sensors on or adjacent to the hub54, the positional markers and sensors in communication with the control circuit32.

Turning now toFIGS. 4,5A,5B,6A, and6B, each of the arm assemblies56comprises a medication vial track62, having a track support member64and a movable track66surrounding the track support member64. The track support member64is an elongated, oval arm having an outer perimeter68. The movable track66is entrained about the outer perimeter68such that the movable track66is movable along the outer perimeter68.

A plurality of vial holders70are disposed along the movable track66, each vial holder70being adapted to retain a medication vial40. A track motor72is engaged to the movable track66to move the movable track66about the track support member64. The track motor72may be a stepping motor or another type of motor adapted for accurate positional control, such that the movable track66may be positioned to bring a vial holder70into alignment with the spiking unit42. Alternatively, positional control of the movable track66may be achieved by use of appropriate positional markers and sensors on or adjacent to the movable track66or the track support member64, the positional markers and sensors in communication with the control circuit32.

In conjunction with the medication vial track62, each of the arm assemblies56comprises a vial-handling arm74. The vial-handling arm74comprises a fixed member130, the fixed member130being generally a hollow tubular member. A telescoping member132slidably extends from the fixed member130. A first actuator134, such as a solenoid, is disposed within the fixed member130and connected to the telescoping member132such that the telescoping member132may be extended and retracted by the first actuator134.

A vertically pivoting member136is pivotally attached to the telescoping member132. A second actuator138, such as a solenoid, is employed to move the vertically pivoting member136upward and downward. The second actuator138is disposed on the vertically pivoting member136, and is connected to a lever arm140disposed on the telescoping member132.

A vial grasping mechanism76is disposed on the vertically pivoting member136, positioned to grasp a medication vial40from the medication vial track62in alignment with the spiking unit42. A third actuator142is disposed on the vertically pivoting member136, and is in connection with the vial grasping mechanism76to move the vial grasping mechanism76between an open and a closed position.

The second actuator138moves the vertically pivoting member136vertically such that a grasped medication vial40may be removed from the medication vial track62and spiked onto the spiking unit42, and such that a medication vial40may be lifted from the spiking unit42for disposal, the vial grasping mechanism76dropping the medication vial40into the disposal chute31. A barcode reader78is disposed on the vertically pivoting member136and oriented to read a barcode label on a medication vial40before removal of the medication vial40from the medication vial track62.

Turning now toFIG. 7, the spiking unit42and mixing chamber44are illustrated in greater detail. The mixing chamber44comprises an enclosed receptacle having a hollow interior80. The spiking unit42is essentially a hollow spike, or needle, extending from the mixing chamber44, and in fluid communication with the hollow interior80of the mixing chamber44. The spiking unit42is adapted for insertion into a medication vial40such that the contents of the medication vial flow into the hollow interior80of the mixing chamber44. An aperture82formed along the length of the spiking unit allows entry of air into a spiked medication vial40to facilitate emptying of the contents of the medication vial40into the mixing chamber44.

A fluid entry port84is located near the top of the mixing chamber44. The fluid entry port84is connected, by a fluid conduit86, to the first pump46so that a fluid may be pumped by the first pump46into the mixing chamber44. In use, a fluid source, such as IV bag50, is connected to the first pump46to supply fluid to the mixing chamber44. A fluid exit port88is located near the bottom of the mixing chamber44. The fluid exit port88is connected by a fluid conduit90to a second pump48so that a fluid may be pumped out from the mixing chamber44. In use, the second pump48is connected to IV line12for delivery of the fluid and a medication to a patient P.

The hollow interior80of the mixing chamber44has a sufficient volume to contain a single, typical dose of a medication prepared for delivery to the patient. It should be noted that some medications will require dilution with a saline solution before delivery to the patient. Therefore, the volume of the hollow interior80of the mixing chamber44should accommodate a quantity of a fully diluted medication. In the illustrated embodiment, the volume is slightly greater than twenty cubic centimeters (20 CC). The mixing chamber44may be made of a transparent material, and may include visual volumetric indicia92disposed thereon for ready observation of the volume of fluid contained within the mixing chamber44.

A pair of fluid level sensors provide control signals to the control circuit32. A first level sensor94is located near the top of the mixing chamber44at a predefined volumetric level, such as at a twenty cubic centimeters (20 CC) level. The first level sensor94provides a signal to the control circuit32when the fluid level within the mixing chamber44rises above this level. A second level sensor96is located near the bottom of the mixing chamber44at a predefined volumetric level, such as at a five cubic centimeters (5 CC) level. The second level sensor96provides a signal to the control circuit32when the fluid level within the mixing chamber44falls below this level.

Turning now toFIG. 8, the control circuit32is discussed in greater detail. The control circuit32is, in the illustrated embodiment, a microcomputer based controller having a central processing unit (CPU)100in communication with a memory102, the memory102including RAM and ROM memories. The CPU100is also in communication with a timer103. Additionally, a reader104for a removable storage medium106may be provided in communication with the CPU100. The control circuit32includes control interfaces108that communicate with the display34and keypad36to provide a user interface for the multiple medication IV pump10. Additionally, the control interfaces108provide for connection to the hub motor58, arm actuators75, the vial grasping mechanism76, the barcode reader78, the first and second pumps46,48, and the first and second level sensors94,96. The control interfaces108provide for the operation of the first pump46and the second pump48at a variable speed such that the fluid volume and rates of the pumps46,48may be controlled by the control circuit32. A computer program stored in the memory102and executed by the CPU100operates the multiple medication IV pump10. A battery109may be provided to power the control circuit32.

A stored medication library110is stored within the memory102. Referring toFIG. 9, the stored medication library110is a database of the types of medications that will be used with the multiple medication IV pump10. The stored medication library110includes an entry112for each of the medications that will be used with the multiple medication IV pump10, each entry102including at least the name114of the medication, the dosage116, a dilution factor118if the medication is to be diluted for use, and a repeat interval120if the medication is to be administered repeatedly. The stored medication library110may be stored in the ROM portion of the memory102, or may be stored on a removable storage medium106, the removable storage medium adapted for use with the reader104, and loaded into the RAM portion of the memory102. In addition to individual medication entries, the stored medication library110may include entries that indicate a medication protocol or series, wherein a medication protocol or series is simply a series of medications to be administered in a predetermined sequence and at predetermined dosages and intervals.

Turning now toFIG. 10, a typical operating sequence of the multiple medication IV pump10is described. The control circuit32displays a menu of selections on the display34(step902). A user enters a selected operation using the keypad36. Before operation of the multiple medication IV pump10to deliver a fluid or medication to a patient, the multiple medication IV pump10must be primed.

The priming steps (not shown) include attaching an IV bag50or other fluid source to the first pump46, attaching an IV line12to the second pump48, and operating the multiple medication IV pump10in a priming mode to ensure that the fluid from the IV bag50displaces all of the air in the system and the attached IV line12. During the priming process, the fluid is pumped by the first pump46into the mixing chamber44. Once the fluid level within the mixing chamber44reaches the second level sensor96, the second pump48is activated to pump the fluid through the IV line12. Once the fluid reaches the end of the IV line12(or after a sufficient time interval for the fluid to reach end of the IV line12), both pumps46,48are turned off, leaving the multiple medication IV pump10primed with a small amount of the fluid remaining in the mixing chamber44.

With the multiple medication IV pump10primed, the user selects the desired mode of operation. Initially, the user selects between a bolus mode and a drip mode (at904). In the drip mode, used for ordinary infusion of IV fluids, the user enters a volume and rate for the infusion (step906), and then the multiple medication IV pump10begins delivery of the IV drip by operating the first pump46and the second pump48together, controlling the speed of the pumps46,48to achieve the desired infusion rate (step908). To deliver a medication bolus, the bolus mode is selected. A menu of available medications is displayed on the display34, displaying the medications defined in the stored medication library110. The user selects the desired medication (or a medication protocol) using the keypad (step910). Note that a single medication may be selected, or a series or protocol of medications may be selected. In either case, the medication may be delivered according to default values contained within the stored medication library110, or according to customized instructions that are entered when the medication or protocol is selected.

Once a medication has been selected, the medication name and information from the stored medication library is displayed on the display34, along with information about the medication obtained from the stored medication library110. If the medication is to be given repeatedly, an indication is displayed to remind the user. The medication may be repeated manually, at the initiation of the user, or automatically, at the initiation of the control circuit, according to the repeat interval120specified in the medication's entry112within the stored medication library110.

Once a medication selection has been made, the carousel38is activated to position a medication vial40containing the desired medication in position at the spiking unit42(step912). It can be noted at this point that the medication vials40can be placed into the carousel at predetermined and predefined positions so that a given medication is selected by the position of the carousel38. Alternatively, although potentially slower, the medication vials40might be placed randomly within the carousel38and identified by the barcode reader78for use, the medication vials40being retrieved one at a time until the correct medication vial40is found. As an improvement to the random placement, the vials might be randomly placed, with the control circuit then performing a “learning” cycle wherein each of the medication vials40is scanned by the barcode reader for identification, and it's position then recorded.

Assuming that the medication vials40are stored in known positions, the control circuit32activates the hub motor58to rotate the carousel38so that an arm assembly56carrying the a medication vial40containing the desired medication is aligned with the spiking unit42. The control circuit32then activates the track motor72of the arm assembly56to position a medication vial40containing the desired medication in alignment with the spiking unit42.

The barcode reader78is then activated to read a barcode label on the medication vial40aligned over the spiking unit42(step914). If the barcode label does not match the selected medication (at916), an alarm is activated to bring attention to the error condition (step918). If the medication vial40is correct, the vial handling arm74is activated to grasp the medication vial40and to spike the medication vial40onto the spiking unit42(step920), releasing the contents of the medication vial40into the mixing chamber44.

Some medications are to be delivered to the patient undiluted, while others must be diluted with saline solution (or another fluid) before delivery to the patient. The medication's entry112in the stored medication library110indicates whether or not the medication is to be diluted, as reflected by the dilution factor118. If the medication is to be diluted (at922), the first and second pumps46,48are operated in sequence to dilute the medication within the mixing chamber before delivery to the patient (step924). The medication is diluted by operating the first pump46, with the second pump48off, to pump fluid into the mixing chamber44. The first pump is operated by the control circuit32at a predetermined rate, and for a fixed time interval (measured by the timer103), to pump an amount of fluid into the mixing chamber44to dilute the medication according to the dilution factor118. Once the time interval has elapsed, and the correct amount of fluid is pumped into the mixing chamber44, the second pump48is activated to deliver the diluted medication to the patient P, with both pumps46,48operating as the medication is delivered (step926).

If the medication is to be administered undiluted, the second pump48is activated simultaneously with the first pump46, such that the undiluted medication is pumped to the patient P with both pumps46,48operating as the medication is delivered (step926). The first and second pumps46,48continue operation for a sufficient time interval that a fluid flush follows the medication, to ensure that the entire dose of medication is delivered to the patient (step928).

Once the delivery of the medication is completed, the vial handling arm74is activated to remove the medication vial40from the spiking unit42and to deposit the medication vial44into the disposal chute31(step930).

A user programmed medication sequence, or a medication protocol contained within the stored medication library, or a particular medication dosage may require that the process be repeated with the same, or with a different, medication. If the cycle is to be repeated (at932), the control circuit32repeats its operations from step912, activating the carousel38to identify and load the next medication vial40. Otherwise, the process is complete, returning to an initial menu display to await further user operations.

In the embodiment described above, the first and second pumps are described as being contained within the housing of the multiple medication IV pump. In another embodiment, one or both of first and second pumps may be external to the housing. The components of the pumps that come into contact with the medication of the fluids being pumped are selected so that they are chemically inert with respect to the medications being administered by the multiple medication IV pump. The pumps may be peristaltic pumps designed so that the pumped fluids come into contact only with tubing of the same type used for the IV lines.