Pulse infusion device system and method

Aspects of the invention are related to a method and a system for administrating an infusion liquid pulse. The system includes a tubing system having an inlet connected to an external reservoir adapted to contain infusion fluids and an outlet connected to a catheter. The tubing system includes a check valve proximate to the inlet and an anti-siphon valve proximate to the outlet. The system further includes an automatic pulse flow generation device. The automatic pulse flow generation device includes an internal reservoir and a bidirectional pump configured to pump infusion fluid from the external reservoir to the internal reservoir and further pump an infusion fluid pulse from the internal reservoir to be injected by the catheter, the infusion liquid pulse has a volume of at least 2 ml and a velocity of at least 5 ml/min.

FIELD OF INVENTION

The present invention relates to the administration of liquid medicines. More particularly there is disclosed a pulse infusion pump which is programmable to suit the volume, the velocity and frequency as directed by the doctor in charge of the patient and/or by the patient him/herself in pain control applications.

BACKGROUND OF THE INVENTION

Since the early 90's the use of infusion pumps to administer anesthetics has become common practice for achieving continuous regional and local anesthesia. These pumps are either electro-mechanical pumps or mechanical pumps. Most pumps are designed to be ambulatory, carried by the patient in a pouch or similar holder. Some types of pump are suitable for Patient Control Analgesia (PCA) whereby the patient can add additional medication bolus to the basal flow to address severe pain.

Currently there are two main clinical procedures that are used for continuous long-term postoperative regional/local anesthesia, both are subcutaneous/intramuscular. The first procedure is Surgical Site Infiltration (SSI), wherein the medication is introduced into or nearby the surgical incision by use of a catheter with a long fenestrated segment inserted into the patient tissue. The second procedure is Continuous Peripheral Nerve Block (CPNB), wherein medication is introduced proximate to the nerve that controls the limb that has been operated. When CPNB administration is performed, an efficient pain block is achieved due to medication saturation of an area surrounding the nerve. Therefore maintaining sufficient nerve bathing is essential to gain continuous pain blockage. For example, such sufficient nerve bathing is achieved when a nerve block is performed by manual injection, typically performed prior to surgery. One of the main objectives of the present innovation is to continuously maintain sufficient nerve bathing through implementing an innovative infusion strategy for CPNB and thereby gain an improved post-operative pain therapy.

Automatic pumps for continuous medication insertion are well known in the art, for example, insulin pumps. Such devices are configured to continuously inject small amounts of medication, for example, in the order of 1 ml/hour (0.017 milliliter/minute), intravenously (IV) into a human venous. The amounts of medication injected intravenously must be closely controlled as not to harm the venous while continuously injecting the medication. Other IV pumps known in the art can inject larger amount of medication even up to 30 ml/min, however such pumps are not designed to endure pressures higher than 0.2 bar. Such pumps do not suit regional/local anesthesia that requires rapid injection of relatively large amount of anesthetic medication at a relative rapid velocity that is administrated through relative thin and long catheter; requires relatively high pressure, for example, volume of more than 2 ml in a velocity of at least 5 ml/min with 20 G catheter 50 to 100 cm long required a pressure of at least 2.5 bar.

SUMMARY OF THE INVENTION

The device of the invention provides infused medication in a continuous pulse flow at a defined volume and frequency and velocity while maintaining a stable and accurate average flow rate. The device is particularly useful for large volume pulses at low frequency.

Embodiments of the invention may be related to a system for administrating an infusion liquid pulse. The system may include a tubing system having an inlet connected to an external reservoir adapted to contain infusion fluids and an outlet connected to a catheter. The tubing system may further include a check valve proximate to the inlet and an anti-siphon check valve proximate to the outlet. The system may further include an automatic pulse flow generation device. The automatic pulse flow generation device includes an internal reservoir and a bidirectional pump configured to pump infusion fluid from the external reservoir to the internal reservoir and further pump an infusion fluid pulse from the internal reservoir to be injected through a catheter, the infusion liquid pulse has a volume of at least 2 ml and a velocity of at least 5 ml/min.

Other embodiments of the invention may be related to a method of administrating an infusion liquid pulse. The method may include automatically pumping an infusion liquid from an external reservoir to an internal reservoir included in a pulse infusion system, the external reservoir may be adapted to contain infusion fluids and automatically generating the infusion liquid pulse by pumping from the internal reservoir a predetermined volume of an infusion liquid and injecting the predetermined volume at a predetermined velocity, the predetermined volume is at least 2 ml and the predetermined velocity is at least 5 ml/min.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

System100, which is illustrated inFIGS. 1A and 1B, is a stand-alone electro-mechanical infusion system that creates pulsed flow having high volume and high velocity. According to some embodiments of the present invention system100may allow a user to set the volume of the pulse, the frequency of the pulses and the pulse velocity.

According to one embodiment of the present invention, system100may include a tubing system120having an inlet2connected to an external reservoir1adapted to contain infusion fluids and an outlet6connected to a catheter (not illustrated). External reservoir1may be a fluid medication reservoir; solid, semi-solid container or a bag. System100may be an automatic pulsed flow generation device110. According to some embodiments of the present invention, tubing system120may be a disposable tubing system. Tubing system120may further include a check valve3proximate to inlet2and an anti-siphon check valve5proximate to outlet6.

Automatic pulse flow generation device110may include an internal reservoir7, for example, in a form of a tube of a syringe, and a bidirectional pump12. Bidirectional pump12may include a piston (as illustrated inFIG. 1A) and a pulse actuation apparatus8. It should be understood by those skilled in the art that the piston illustrated inFIG. 1Ais given as an example only, and that other bidirectional pumps are in the scope of the present invention. According to other or additional embodiments automatic pulsed flow generation device110may be programmable by a user such as a medical team and/or a patient. According to yet another embodiment of the present invention, automatic pulsed flow generation device110may be pre-set. Bidirectional pump12may be configured to pump infusion fluid from external reservoir1to internal reservoir7and further pump an infusion fluid pulse from internal reservoir7to be injected by the catheter, the infusion liquid pulse may have a volume of at least 2 ml and a velocity of at least 5 ml/min at pulse cycle frequency of 15 minutes or longer.

An exemplary automatic pulsed flow generation device110may comprise an internal pump reservoir7, such as a syringe, a piston12and a pulse actuation apparatus8. During the bidirectional operation syringe7is filled and emptied during each cycle.

Device110may further include a controller (not illustrated) configured to control bidirectional pump12and optionally also valves3and5. In some embodiments, the controller may control pulse actuation apparatus8included in pump12to control the velocity of the infusion pulse, for example to generate or provide an infusion pulse having a velocity of 5-30 ml/min (milliliter/minute). In some embodiments, the controller may control pulse actuation apparatus8included in pump12to control the volume of the infusion pulse, for example, to generate or provide an infusion pulse having a volume of 2-15 ml (milliliter). In some embodiments, the controller may control pulse actuation apparatus8included in pump12to control a frequency at which the pulses are injected, for example, the pulse may be given to a patient between once in every 90 minutes to once in every 10 minutes. The controller may further control the internal pressure at which the pulse is injected. A relatively high pressure, for example, of at least 1.5 or 2 bar may be required to produce a pulse at a velocity of at least 5 ml/min. The controller may control pump12to build a pressure of at least 2 bar in order to inject the pulse at at least 5 ml/min.

The controller may control pump12to pump infusion fluid from external reservoir1to internal reservoir7while opening valve3. In another embodiment, the controller may control pump12to generate an infusion fluid pulse by pumping the infusion fluid from internal reservoir7to outlet6while opening anti siphon check valve5.

According to one embodiment of the present invention, internal reservoir7is filled using energy provided by the flow from external reservoir1. It would be appreciated by those skilled in the art that other mechanisms may be used for filling internal reservoir7with fluid received from external reservoir1.

According to one embodiment of the present invention, pulsed flow generation device110may be operated electromechanically, through an electric motor or solenoid (not shown) which may be controlled by an electronic controller (not shown) in actuation apparatus8. The electronic controller may be programmable or preprogrammed to allow adapting the pulses frequency, the volume and velocity of each pulse of fluid and other parameters in order to tailor these parameters to the needs of each patient.

In some embodiments, device110may include more than one controller. For example, actuation apparatus8may comprise a controller for controlling the pulses frequency (not shown). According to another embodiment of the present invention, actuation apparatus8may comprise another or an additional controller such as a pulsed flow volume controller. Additionally, actuation apparatus8may comprise a flow velocity controller. It would be appreciated by those skilled in the art that other controllers, optionally of other parameters, may be used.

Pulsed flow generation device110may pump a defined volume of fluid, for example, 10 ml, received from external reservoir1to an internal pump reservoir, such as syringe7. Pump12(e.g., a piston) may then pump out that defined volume or a smaller volume, for example, 5 ml, entirely or partially, into a catheter (not shown) placed in the body of the patient. These pumping operations may be performed continuously at a selected frequency, for example, once every 60 minutes.

According to one embodiment of the invention both internal reservoir7and pump12may be parts of a disposable syringe set. Device operation parameters can be preset during manufacturing (pre-programmed) or, in a programmable version, the medical team may have the option to select and set the operational parameters of the device during the course of the therapy and to permanently lock them when needed.

In some embodiments, the device may be an ambulatory type powered by batteries13. However a stationary device can be used where the patient is unlikely to be moved. Energy may then be supplied through a cord14connected to the building electric supply via a transformer-rectifier15.

In some embodiments the system may be operated manually by the patient and/or medical team in addition to the automatically pulses delivery. In some embodiments, the system may be operated manually only by the patient and/or medical team. In some embodiments, when operated manually system100may be configured to supply an infusion liquid pulse having a volume of at least 2 ml and a velocity of at least 5 ml/min.

FIG. 1Arepresents an electromechanical pulsed flow generation device110. Tubing system120compromise inlet tube2that may be connected at one end to external reservoir1by use of a standard fitting and on the other end to check valve3. A connector, such as a T shape connector4, may be positioned between said check valve and an anti-siphon check valve5. Outlet port6may be positioned after said anti-siphon check valve. Outlet port6may have standard fitting to be connected to an NB catheter placed in the patient body or any other fluid insertion apparatus known in the art. The remaining branch of T connector4opens into variable volume container such as a standard disposable syringe7. It would be appreciated by those skilled in the art that actuation apparatus8of device110may be disposable or reusable, while tubing system120and external reservoir1are usually disposable components.

Internal reservoir7may be connected to electromechanical programmable actuation apparatus8by mounting the reservoir barrel11onto a holder9and the piston rod12to the pull lever10.

Check valve3may further prevent back-flow of fluids from connector4to external reservoir1. Anti-siphon check valve5may further prevent gravity flow from reservoir1to exit port6and prevents back flow from exit port6to connector4.

Pull lever10of actuation apparatus8may move linearly only along one axis of pump12(in the direction of the double-headed arrow indicated inFIGS. 1A and 1B) so that when pull lever10moves in a first direction, the internal volume of internal reservoir7increases and when pull lever10moves in a second direction the volume of internal reservoir7decreases.

Movement in the first direction of the pull lever10, driven by the actuation apparatus8, draws the pump (e.g., piston)12in the same first direction, creating a vacuum in the cylinder of syringe which serves as internal intermittent reservoir7. As a result fluid is drawn from reservoir1into internal reservoir7.

Movement of pull lever10in said second direction applies pressure on the fluid in internal reservoir7that pumps out the medication from said internal reservoir7to the patient through anti-siphon check valve5and through outlet port6.

Electronic programmable means of actuation apparatus8may enable to determine the volume that to be pumped into syringe7every and each movement cycle of pull lever10(e.g., 15 ml) in the first direction and the volume that is pumped out of syringe7(e.g., 5 ml) every and each movement of pull lever10in the second direction. Frequency of pull lever10movement may also be pre-set and controlled. Similarly, the speed of movement of pull lever10may also be pre-set and controlled.

According to some embodiments of the present invention, actuation apparatus8may be equipped with electronic means to store and analyze the infusion data and to sound an alarm when data received and recorded is outside pre-defined limits. For example, when the total pulsed flow volume is beyond a predefined maximum dosage.

FIG. 1Bshows the electromechanical pulse infusion system100, presenting the system in a situation where the pull lever10has moved in the second direction to its extremity, i.e. pumping out the fluids within syringe7. According to the embodiment illustrated inFIG. 1B, device110may be arranged to receive power from a wall socket, using a transformer-rectifier15and a cable14.

Reference is made toFIG. 1Cthat is a schematic illustration of a stationary pulse infusion system100according to some embodiments of the invention. External reservoir1in a form of a plastic bag may be placed on a pole near or above a patient's bad. Tubing system120may connect the bag to system100and may further be connected to a catheter. System100may further include a manual pulse flow controlling device260, allowing the patient and/or medical team member to manually control pulse flow generation device110to give an additional pulse of medication upon the patient's request (regardless of the administration frequency determined and programmed in the automatic pulse flow generation device).

In some embodiments, System100may be configured to deliver manual pulse flow only.

Reference is made toFIG. 1Dthat is a schematic illustration of an ambulatory pulse infusion system100according to some embodiments of the invention. External reservoir1may be placed inside or attached to the body of system100to be carried out by the patient. An ambulatory system100may further include a tubing system120and a manual pulse flow controlling device260as disclosed above.

Reference is now made toFIG. 2which is a schematic drawing of another electromechanical embodiment of the present invention. As may be seen inFIG. 2, tubing2is connected to an inlet port52through an optional one-way valve3. A connector such as a T shape connector4leads to an anti-siphon check valve5and an exit port20.

Pulse flow generation device110is also connected to the ‘T’ connector4. Pulsed flow generation device110is equipped with a pump (e.g., piston)12, an optional spring26, an electric actuation apparatus8and a sensor (proximity switch)30. Syringe7is filled and discharges through connector4.

A fluid, such as fluid medicament, may flow from an infusion pump (not shown) through inlet port52, and through valve3. The fluid flowing into tube2between valves3and5may cause pressure build-up and push piston12in the first direction to increase the volume of fluid that may be contained in syringe7. When the volume of fluid within syringe7reaches a predefined volume, actuation apparatus8causes piston12to start moving in a second direction to pump out the fluid contained in syringe7. When fluid is pumped out from syringe7into tube2, pressure in tube2increases until pressure check valve5is opened, and a pulse of fluid may flow through the pressure-activated check valve5and may exit into a patient's body through outlet port20.

According to one embodiment of the present invention, as piston12reaches the vicinity of proximity switch30an electric signal causes actuation apparatus8to move in a second direction and applies an additional force on compression spring26. Spring26in turn pushes liquid out of device110forcing valve5to open and release a pulse of fluid medication. Spring26acts as a buffer between the fast actuation apparatus8and the slower movement of the piston12. According to yet another embodiment of the present invention, actuation apparatus8retracts to its original position after a preset delay, typically between 1 and 3 seconds. The reduced fluid pressure in syringe7allows new fluid therein thus starting a new cycle.

It would be appreciated by those skilled in the art that spring26may not be required and other buffer mechanisms may be used. It would be further realized that a buffer may not be required at all.

Means are provided to change the position of sensor or proximity switch30, thus adjusting the pulsed fluid volume. Other means for adjusting the volume of fluid released in each pulse may be used.

In an alternative embodiment sensor30is a component which continuously monitors piston12position and transmits signals to a programmable controller (PEC) (not illustrated). The PEC is easily set to a desired fluid volume per pulse, and additionally any desired time delay can be programmed therein.

Referring now toFIG. 3that is an illustration of a pulse flow generation device110according to some embodiments of the invention. Device110ofFIG. 3is almost identical to that seen inFIG. 2except that no sensor (proximity switch) is provided. A PEC (not shown) controls the actuation apparatus8, generating an electric signal according to a time interval set by the medical team. The signal connects power to the actuation apparatus8to move in a second direction to pump out fluid from syringe7and the pulse is generated exactly as described with reference toFIG. 2. The time interval set in the PEC may be easily changed, and thus different pulsed volumes can be ejected while using the same basic flow rate.

Turning now toFIG. 4, which illustrates an embodiment provided with a syringe7having an internal container34made of an elastic material, for example of silicone rubber positioned inside a rigid container32. Internal container34has a controlled volume and is beneficial in preventing any leak of a fluid into the pump mechanism. Furthermore, internal container34reduces the area of contact between the fluid and parts of the pump. In all other respects the present embodiment is identical to the embodiment described with reference toFIG. 2.

With regard toFIG. 5, which illustrates an embodiment similar to that shown inFIG. 4, except that a PEC (not shown) comprised within actuation apparatus8creates an electric signal according to a time interval set by the user. Therefore switch or sensor30seen inFIG. 4may not be required.

FIGS. 6A and 6Billustrate a mechanical pulse device, so there is no electric actuation apparatus8as was seen in previous embodiments.

Tubing2is connected to an inlet port52through an optional one-way valve3. A connector such as T shaped connector4leads to a pressure-activated check valve40and an exit port20.

Pulsed flow generation device110is also connected to the ‘T’ connector4. Pulsed flow generation device110may be equipped with a piston12, a spring26, and a projection38.

The normally closed valve40thus prevents fluid discharge through outlet port20, wherefore incoming fluid accumulates in syringe7.

Valve40may be actuated by a lever36when pushed by projection38.

A fluid, such as a fluid medicament may flow from an infusion pump (not seen) through inlet port52. During pressure build up in connector4and in the syringe7piston12moves in a first direction to increase the volume of fluid contained in syringe7until projection38contacts a part of lever36, opening valve40and forcing a pulse of liquid through port20.

The reduced fluid pressure in syringe7then allows the entry of new fluid into syringe7thus starting the next cycle.

Means are provided to change the position of the projection38relative to the dimensions of pulse flow generation device110, thus adjusting the pulse volume. According to another embodiment, two projections, lower and upper may be used instead of projection38. The lower projection can be adjusted by the medical team member for varying the pulse volume. It would be appreciated that other means for adjusting the pulsed volume may be used.

Turning now toFIGS. 7A and 7Bthat illustrate the almost identical embodiment shown in previous figures,FIGS. 6A and 6B, the only difference being that syringe7comprises an internal container made of an elastic material, for example of silicone rubber The advantages of this arrangement have been explained with reference toFIG. 4.

Referring now toFIG. 8, which is an illustration of an arrangement of a mechanical pulse device similar to the devices seen inFIGS. 6A and 6B. An elastic band42may be connected to projections44while being tensioned over a piston rod46. The elastic band42thus replaces the compression spring26seen in previous embodiments, and being external can be easily replaced when necessary.

The pulsed flow generation device110can be an integral part of an infusion pump or may be connectable to any infusion pump known in the art.

Reference is now made toFIG. 9which is a flowchart of a method for converting a constant flow into a pulse flow according to an embodiment of the present invention. The method comprising the following steps:

Releasing a fluid, such as an infusion medicament, from an external reservoir such as an infusion pump [Block1000]. The fluid may than pass through a one-way valve to prevent the fluid from returning to the external reservoir [Block1010].

Since the fluid flowing form the external reservoir is prevented from returning to the reservoir by the one-way valve, and cannot pass another valve, such as an anti-siphon check valve, the fluid enters and contained in an internal reservoir, such as a syringe [Block1020].

When the volume of fluid in the internal reservoir reaches a predefined value, for example, 30 ml, an actuation apparatus applies pressure on the fluid contained in the reservoir and thus releases the contained fluid in an at least one pulsed flow [Block1030].

According to one embodiment of the present invention, the volume of fluid contained in the internal reservoir may be released in several consecutive pulses, each pulse having a volume which is relative to the number of pulses. For example, if the reservoir has been filled with 30 ml of fluid medication, it may be released in one pulse of 30 ml, or may be released in 3 consecutive pulses of 10 ml. each.

Reference is now made toFIG. 10Awhich is an illustration of an automatic pulse flow generation device according to some embodiments of the invention. Device110may include, a device body201, made for example, from a rigid polymer, a screen202, a keyboard203and a housing204for holding an internal reservoir and bidirectional pump, for example, in the form of syringe250illustrated inFIG. 11. Housing204may include holder214for holding the syringe. In some embodiments, holder214may include more than one component, for example, an internal reservoir holder213and a bidirectional pump holder212. In the exemplary embodiment ofFIG. 10, the internal reservoir holder213holds a syringe barrel and a bidirectional pump holder212holds a plunger of a piston. Housing204may further include a lever211to support the movement of the piston and a switch215for verifying that the internal reservoir was inserted into holder214and that a compatible internal reservoir is being used, for example in order to avoid administration errors such as overdosing or underdoing due to an insertion of a wrong internal reservoir.

FIG. 10Bis a high level block diagram that includes some of the components of device110. Device110may further include a motor220(e.g., a servo motor) and a transmission221for transmitting a translational (or rotational) movement to lever211positioned over a shaft222. Motor220may be powered by a battery225via a power supply unit224. Device110may further include a controller230.

Controller230may be configured to control at least some of the elements included in system100and device110, for example, motor220and lever211. Controller230may further be configured to control the bidirectional pump (e.g., pumps12and251). Controller230may include any computation platform that may be configured to control system100according to code saved in a non-transitory memory associated with the controller, which when executed causes system100to perform methods of the invention. Additionally or alternatively controller230may executed instructions received from a user using a user interface associated with controller230, for example, using keyboard203and/or screen202. Screen202may be a touch screen or any other display known in the art. Controller230may include a processor (e.g., a CPU, microcontroller, programmable logic controller (PLC) and the like), a non-transitory memory for storing codes that when executed by the processor perform methods according to embodiments of the invention. Controller230may be associated with a user interface (e.g., a graphical user interface) that may include any devices that allow a user to communicate with the controller.

Controller230may control system100and device110to pump infusion fluid from the external reservoir to the internal reservoir and further pump an infusion fluid pulse from the internal reservoir to be injected by the catheter, the infusion liquid pulse may have a volume of at least 2 ml and a velocity of at least 5 ml/min.

Reference is now made toFIG. 11which illustrates an exemplary internal reservoir and bidirectional pump, to be attached to device110illustrated inFIG. 10according to some embodiments of the invention. A syringe250may include an internal reservoir253, for example, in the form of a barrel and a bidirectional pump251, for example, in the form of a plunger pump and a piston located inside internal reservoir253. Internal reservoir253may have a volume of 2-50 ml, for example, 15 ml. A Piston may be connected to a plunger pump (as illustrated) to form the bidirectional pump251. Bidirectional pump251may be configured to pump infusion fluid from external reservoir, such as reservoir1, to internal reservoir253and further pump an infusion fluid pulse from internal reservoir253to be injected by the catheter, the infusion liquid pulse may have a volume of at least 2 ml and a velocity of at least 5 ml/min. Controller230may be configured to cause bidirectional pump251to pump infusion liquid to or from internal reservoir253, for example, by controlling motor220to move lever211to push or pull the plunger of pump251. Syringe250may further include an indicator254for identifying the syringe, for example, in order to verify that the syringe is in the correct volume or contains the correct substance.

In the embodiment ofFIG. 11, the internal reservoir and the bidirectional pump are included in a single device, syringe250. However, in other embodiments of the invention the internal reservoir and the bisectional pump may each be a standalone component connected together via tubing system. The bidirectional pump may be any pump configured to pump liquids to and from a reservoir. For example, the bidirectional pump may include: a plunger pump (as illustrated), a peristaltic pump, a roots-type pump or any other pump known in the art. The internal reservoir may include any container configured to hold infusion fluids. The internal reservoir may have a constant volume or a changeable volume that may vary with the amount of infusion fluid in the reservoir.

Reference is made toFIGS. 12 and 13that are illustrations of tubing systems120according to some embodiments of the invention. Both systems120ofFIGS. 12 and 13may include one-way check valve123, Y connector124, syringe connector122, patient clamp125, filer126, anti-siphon one way check valve127and outlet port131. The tubing system ofFIG. 12further includes piercing device121at the inlet port proximate to valve123. The tubing system ofFIG. 13may further include an external reservoir130, a medical team clamp128and a filling port129.

Reference is made toFIG. 14that is an illustration of a manual controller (e.g., controller260) for controlling device110to apply a Patient Control Analgesia (PCA) and/or a Clinician Bolus by operating system100to inject infusion liquid pulse, for example, upon a request from the patient or a decision made by a medical professional. The injected infusion liquid pulse may have a volume of at least 2 ml and a velocity of at least 5 ml/min. The manual controller may include a housing261, a push button262to be pushed by the patient, a wire263and a plug264. The manual controller may be configured to cause an application of a predetermined amount of medication at a predetermined velocity, for example, 3 ml at 5 ml/min when the patient/clinician pushes button262, regardless of the frequency of infusion liquid pulse programmed in automatic device110. The manual controller may be operated in addition to the automatic administration programmed in automatic device110or separately when no administration is programmed in automatic device110. It should be appreciated by those skilled in the art that in order to avoid overdosing, a lock time period during which additional pulses cannot be initiated by the patient may be set. It should be further appreciated that the predetermined amount of medication released by the patient and/or clinician may be reduced from the total volume of liquid in the internal reservoir and thus from the total volume of medication given to the patient in a given time interval.

Reference is made toFIG. 15which is a flowchart of a method of administrating an infusion liquid pulse according to some embodiments of the invention. The method ofFIG. 15may be performed by pulse infusion system100, disclosed above. In box1510the method may include automatically pumping an infusion liquid from an external reservoir (e.g., reservoir1) to an internal reservoir (e.g., internal reservoirs7or253) included in a pulse infusion system, the external reservoir may be adapted to contain infusion fluids. System100may automatically pump the infusion liquid from the external reservoir every predetermined amount of time, for example, at least once in every 90 minutes, or every shorter periods of time. The infusion liquid may be pump using bidirectional pump.

In box1520, the method may include automatically generating the infusion liquid pulse by pumping a predetermined volume of an infusion liquid from the internal reservoir and injecting the predetermined volume at a predetermined velocity, the predetermined volume may be at least 2 ml and the predetermined velocity may be at least 5 ml/min. The infusion liquid pulse may be generated using the bidirectional pump. The infusion liquid pulse may be injected to a patient via a catheter. In some embodiments, the predetermined volume may be between 2 ml to 15 ml. In some embodiments, the predetermined velocity may be between 5 ml/min to 30 ml/min. In some embodiments, the pressure of the infusion liquid pulse inside the internal reservoir may be any predetermined pressure to enable injecting the predetermined volume at a predetermined velocity, for example in the range of 2-4 bars.

In box1530, the method may include manually generating the infusion liquid pulse by pumping a predetermined volume of an infusion liquid from the internal reservoir and injecting the predetermined volume at a predetermined velocity, the predetermined volume may be at least 2 ml and the predetermined velocity may be at least 5 ml/min. The infusion liquid pulse may be generated by controlling a manual controller (e.g., by pushing button262) to operate the bidirectional pump. The infusion liquid pulse may be injected to a patient via a catheter. In some embodiments, the predetermined volume may be between 2 ml to 15 ml. In some embodiments, the predetermined velocity may be between 5 ml/min to 30 ml/min. In some embodiments, the pressure of the infusion liquid pulse inside the internal reservoir may be any predetermined pressure to enable injecting the predetermined volume at a the predetermined velocity, for example, in the range of 2-4 bars.

In some embodiments, the method may include repeating the automatic generation of the infusion liquid pulse every predetermined duration of time, for example, at least once in every 90 minutes. In some embodiments, the method may include repeating the automatically pumping the infusion liquid from the external reservoir and automatic generation of the infusion liquid pulse every the same predetermined amount of time.