Patent Description:
Pumps are often used in the medical industry for delivering fluids, e.g., drugs or diagnostic fluids, to subjects. One type of medical pump is an infusion pump, used to infuse a fluid into a subject's circulatory system via infusion tubing. Some infusion pumps include a valve, or system of valves, that may occlude flow within the infusion tubing by pressing on the outside of the fluid-filled infusion tubing. Often infusion pumps engage with the infusion tubing via tube cassette. A common safety feature of tube cassettes is an anti-free-flow valve that ensures that the infusion tubing is occluded in the event that the tube cassette is disengaged from the pump. Relevant prior art documents include <CIT>, <CIT> and <CIT>.

A tube cassette and infusion pump for delivering a fluid to a subject are provided, in accordance with some applications of the present invention. The tube cassette receives the infusion tubing and is removably couplable to the pump. The tube cassette comprises an anti-free-flow valve that occludes the infusion tubing and can be actuated by a force external to the tube cassette to terminate the occlusion. Thus, in the absence of the external force, i.e., in its rest-state, the anti-free-flow valve occludes the infusion tubing. The infusion pump, e.g., a volumetric infusion pump, or peristaltic infusion pump, delivers the fluid to the subject by repeatedly (a) pressing on the infusion tubing with a pressing surface so as to push fluid toward the subject and then (b) raising the pressing surface from pressing on the infusion tubing so as to intake more fluid from a fluid source. When the tube cassette is coupled to the pump, as part of a pumping cycle for delivering the fluid to the subject, the pump repeatedly (a) actuates the anti-free-flow valve to terminate the occlusion of the infusion tubing, and subsequently (b) releases the anti-free-flow valve, allowing it to return to its rest state and occlude the infusion tubing. Thus, the pump uses the anti-free-flow valve of the tube cassette to deliver the fluid from the fluid source to the subject.

For some applications, the tube cassette comprises a lever, the anti-free-flow valve being disposed on the load arm (further described hereinbelow) of the lever. The lever is spring-loaded so as to maintain the anti-free-flow valve occluding the infusion tubing. The anti-free-flow valve may be actuated to terminate the occlusion by a force applied to the effort arm (further described hereinbelow) of the lever, in opposition to the spring loading of the lever. The anti-free-flow valve may be manually actuated to terminate the occlusion by a user when the tube cassette is not coupled to the pump, e.g., by the user pressing on the effort arm of the lever in opposition of the spring loading. Additionally, the anti-free-flow valve may be actuated to terminate the occlusion by a force applied by the pump to the effort arm of the lever in opposition of the spring loading.

There is therefore provided, in accordance with some applications of the present invention, apparatus for delivering a fluid to a subject through infusion tubing, the apparatus including:.

For some applications, the pump includes a pressing surface configured to press on the infusion tubing when the tube cassette is coupled to the pump.

For some applications, the anti-free-flow valve is configured to occlude the infusion tubing in the absence of any force external to the tube cassette being applied to the anti-free-flow valve.

For some applications, the anti-free-flow valve is configured to be actuated by the subject to terminate the occlusion of the infusion tubing when the tube-cassette is not coupled to the pump.

For some applications, a length of the tube cassette is <NUM> - <NUM>.

For some applications, the pump includes at least one pump-valve disposed within the pump and configured to occlude the infusion tubing when the tube cassette is coupled to the pump.

For some applications, the at least one pump-valve is exactly one pump-valve, and is the only valve disposed within the pump when the tube cassette is not coupled to the pump.

For some applications, the pump is configured to deliver the fluid to the subject by repeatedly, sequentially:.

For some applications, the anti-free-flow valve is configured to be actuated to terminate the occlusion of the infusion tubing, upon the force external to the tube cassette being applied at a location along the infusion tubing longitudinally displaced from a site where the anti-free-flow valve occludes the infusion tubing.

For some applications, the tube cassette further includes a lever, the anti-free-flow valve being.

For some applications, the anti-free-flow valve is configured to be actuated to terminate the occlusion of the infusion tubing by the external force having any of a range of values, the range of values including <NUM> N.

For some applications, the range of values includes <NUM> N.

There is further provided, but not claimed, apparatus for delivering a fluid to a subject through infusion tubing, the apparatus including:
a volumetric infusion pump including:.

There is further provided, but not claimed, apparatus for use with a pump and infusion tubing, the apparatus including:
a tube cassette.

For some applications, the anti-free-flow valve is configured to be actuated to terminate the occlusion of the infusion tubing by the force, applied manually or by the pump, having any of a range of values, the range of values including <NUM> N.

Reference is now made to <FIG>, which is a schematic illustration of a tube cassette <NUM>, in accordance with some applications of the present invention. Tube cassette <NUM> receives infusion tubing <NUM> and is removably couplable to a pump <NUM> (shown in <FIG>, <FIG>, and <FIG>), such that pump <NUM> engages with infusion tubing <NUM> via tube cassette <NUM>. Tube cassette <NUM> comprises an anti-free-flow valve <NUM> that occludes infusion tubing <NUM> and can be actuated by a force external to tube cassette <NUM> to terminate the occlusion of infusion tubing <NUM>. Thus, in the absence of any force external to tube cassette <NUM> being applied to anti-free-flow valve <NUM>, i.e., anti-free-flow valve <NUM> is in a rest-state, anti-free-flow valve <NUM> occludes infusion tubing <NUM>. Typically, when tube cassette <NUM> is not coupled to pump <NUM>, such as is shown in <FIG>, anti-free-flow valve <NUM> may be manually actuated by the subject to terminate the occlusion of infusion tubing <NUM>, as is further described hereinbelow.

Typically, anti-free-flow valve <NUM> is actuated to terminate the occlusion of infusion tubing <NUM> upon the external force being applied at a location along the infusion tubing, represented by dashed line <NUM>, that is longitudinally displaced from a site where anti-free-flow valve <NUM> occludes infusion tubing <NUM>, represented by dashed line <NUM>. For some applications, the longitudinal displacement of where the force is applied, e.g., of pressable actuator <NUM>, from where the infusion tubing is occluded may be a distance D of at least <NUM> and/or less than <NUM>. Typically, tube cassette <NUM> comprises a pressable actuator <NUM> to which the external force used to actuate anti-free-flow valve <NUM> is applied. For example, when not coupled to pump <NUM>, the subject may press on pressable actuator <NUM> in order to actuate anti-free-flow valve <NUM> to terminate the occlusion of infusion tubing <NUM>.

For some applications, the longitudinal displacement of where the external force is applied, e.g., of pressable actuator <NUM>, from the site where anti-free-flow valve <NUM> occludes infusion tubing <NUM>, is achieved by tube cassette <NUM> comprising a lever <NUM>. As is known in the field of mechanics, a first-class lever has a load arm and an effort arm positioned on either side of a fulcrum. Anti-free-flow valve <NUM> is disposed on, e.g., at the end of, a load arm <NUM> of lever <NUM> and pressable actuator <NUM> is disposed on, e.g., at the end of, an effort arm <NUM> of lever <NUM>. A fulcrum <NUM> is disposed between load arm <NUM> and effort arm <NUM>. Lever <NUM> is spring loaded, e.g., by a spring <NUM> positioned between a housing <NUM> of tube cassette <NUM> and pressable actuator <NUM>, so as to maintain anti-free-flow valve <NUM> occluding infusion tubing <NUM>. Anti-free-flow valve <NUM> is actuated to terminate the occlusion of infusion tubing <NUM> by the force external to tube cassette <NUM> being applied to effort arm <NUM> of lever <NUM>, e.g., to pressable actuator <NUM> at the end of effort arm <NUM>, in opposition to the spring loading.

Using a lever to displace (a) where the force is applied to actuate anti-free-flow valve <NUM> from (b) where the occlusion of infusion tubing <NUM> occurs, enables anti-free-flow valve <NUM> to be actuated to terminate the occlusion with relatively low force. For example, the force external to tube cassette <NUM> required to actuate anti-free-flow valve <NUM> can be as low as <NUM> N, e.g., <NUM> N, e.g., <NUM> N, e.g., <NUM> N, e.g., higher.

Reference is now made to <FIG>, which are schematic illustrations showing tube cassette <NUM> and pump <NUM> before and after tube cassette <NUM> has been coupled to pump <NUM>, in accordance with some applications of the present invention. Typically, pump <NUM> delivers the fluid to the subject from a fluid source via infusion tubing <NUM> by repeatedly pressing on infusion tubing <NUM> with a pressing surface and then raising the pressing surface from pressing on infusion tubing <NUM>. For example, pump <NUM> may be a volumetric infusion pump, or a peristaltic infusion pump. <FIG> shows tube cassette <NUM> in position to be coupled to pump <NUM>, by being inserted into pump <NUM>, as represented by arrow <NUM>. Within pump <NUM> is an anti-free-flow-valve-actuator <NUM> that is positioned to press on pressable actuator <NUM> when actuated to do so by pump <NUM>. As part of the pumping cycle for delivering the fluid to the subject, pump <NUM> repeatedly (a) actuates anti-free-flow valve <NUM> to terminate the occlusion of infusion tubing <NUM>, and subsequently (b) releases anti-free-flow valve <NUM> to occlude infusion tubing <NUM>. That is, pump <NUM> uses anti-free-flow valve <NUM> to deliver the fluid from the fluid source to the subject.

Typically, pump <NUM> is a volumetric pump that delivers the fluid to the subject by controlling two valves that occlude the infusion tube on either side of a pressing surface that presses on the infusion tube (as further described hereinbelow with reference to <FIG>). Pump <NUM> comprises a pressing surface <NUM>, that presses on infusion tubing <NUM> and at least one, e.g., exactly one, pump-valve <NUM> which occludes infusion tubing <NUM>. When tube cassette <NUM> is coupled to pump <NUM>, anti-free-flow valve <NUM> is positioned to occlude infusion tubing <NUM> on a first side <NUM> of pressing surface <NUM>, and pump-valve <NUM> is positioned to occlude infusion tubing <NUM> on a second side <NUM>, opposite first side <NUM>, of pressing surface <NUM>. For some applications, pump-valve <NUM> is the only valve disposed within pump <NUM> when tube cassette <NUM> is not coupled to pump <NUM>.

Using anti-free-flow valve <NUM> as a valve that is part of the delivery cycle saves space within tube cassette <NUM>, as it is no longer necessary for tube cassette <NUM> to be long enough to accommodate an anti-free-flow valve, an upstream valve of the pump and a downstream valve of the pump. Rather anti-free-flow valve <NUM> is used as either the upstream or the downstream valve during the pumping cycle. Typically, a length L of tube cassette <NUM> is at least <NUM> and/or less than <NUM>.

Reference is now made to <FIG>, which are schematic illustrations depicting the actuation and subsequent release of anti-free-flow valve <NUM> by pump <NUM>, in accordance with some applications of the present invention. <FIG> shows the positioning of pressable actuator <NUM> at the end of effort arm <NUM> of lever <NUM>, anti-free-flow-valve-actuator <NUM> and anti-free-flow valve <NUM> when tube cassette <NUM> is first coupled to pump <NUM>. To actuate anti-free-flow valve <NUM> to remove the occlusion of infusion tubing <NUM>, pump <NUM> actuates anti-free-flow-valve-actuator <NUM> to press on pressable actuator <NUM> at the end of effort arm <NUM>, in opposition of the spring loading, e.g., in opposition of the spring force provided by spring <NUM>. This pressing of pressable actuator <NUM> is represented by downward facing arrow <NUM> in <FIG>. As a result, load arm <NUM> moves in an opposite direction, represented by upward arrow <NUM> in <FIG>, thereby lifting anti-free-flow valve <NUM> away from infusion tubing <NUM> to terminate the occlusion of infusion tubing <NUM>.

When anti-free-flow-valve-actuator <NUM> is moved, by pump <NUM>, in an upward direction, represented by upward arrow <NUM> in <FIG>, anti-free-flow-valve-actuator <NUM> no longer presses on pressable actuator <NUM>, thereby allowing the spring loading of lever <NUM> to push pressable actuator <NUM> back up to its starting position, and in turn, anti-free-flow valve <NUM> back down to its occluding position, represented by downward arrow <NUM> in <FIG>.

Reference is now made to <FIG>, which are schematic illustrations depicting a pumping cycle of pump <NUM>, in accordance with some applications of the present invention. To deliver the fluid to the subject, pump <NUM> repeatedly, sequentially, cycles through the different positions shown in <FIG> shows pump <NUM> and tube cassette <NUM> in a starting position when tube cassette <NUM> is coupled to pump <NUM>. Typically, pressing surface <NUM> starts in a position in which it is pressing down on infusion tubing <NUM>. Pump-valve <NUM>, which in this configuration is acting as an upstream valve, starts in an open position such that there is no occlusion of infusion tubing <NUM> upstream of pressing surface <NUM>. Pump <NUM> intakes the fluid from a fluid source by increasing the volume of a pumping segment of infusion tubing <NUM> (i.e., the segment of infusion tubing <NUM> that is disposed between pump-valve <NUM> and anti-free-flow valve <NUM>) by raising pressing surface <NUM> from pressing on infusion tubing <NUM>. The raising of pressing surface <NUM> is represented by upward arrow <NUM> in <FIG>. Subsequently to the intake of the fluid, pump <NUM> closes the upstream valve, i.e., pump-valve <NUM>, so as to occlude infusion tubing <NUM> upstream of pressing surface <NUM>, as represented by downward arrow <NUM> in <FIG>.

Subsequently, pump <NUM> actuates anti-free-flow-valve-actuator <NUM> to press on pressable actuator <NUM>, thereby terminating the occlusion of infusion tubing <NUM> downstream of pressing surface <NUM>. Downward arrow <NUM> in <FIG> represents anti-free-flow-valve-actuator <NUM> pressing downward, and upward arrow <NUM> in <FIG> represents anti-free-flow valve <NUM> terminating the occlusion of infusion tubing <NUM> downstream of pressing surface <NUM>.

Subsequently, pump <NUM> actuates pressing surface <NUM> to press on infusion tubing <NUM> to push the fluid to the subject, represented by downward arrow <NUM> in <FIG>. Subsequently, anti-free-flow-valve-actuator <NUM> is lifted, represented by upward arrow <NUM> in <FIG>, and anti-free-flow valve <NUM> resumes its occlusion of infusion tubing <NUM>, represented by downward arrow <NUM> in <FIG>. Upon the completion of the pumping cycle, the upstream valve, i.e., pump-valve <NUM>, is opened so as to terminate the occlusion upstream of pressing surface <NUM>, thereby returning pump <NUM> to the starting position of <FIG> (in which pressing surface <NUM> is pressing on infusion tubing <NUM> and pump-valve <NUM> is open), in preparation for the intake of fluid for the next pumping cycle.

It is noted that in the configuration depicted, pump-valve <NUM> acts as the upstream valve, and anti-free-flow valve <NUM> acts as the downstream valve. This, however, is non-limiting, and it is within the scope of the present invention for pump-valve <NUM> to be positioned as the downstream valve and anti-free-flow valve <NUM> to be positioned as the upstream valve when tube cassette <NUM> is coupled to pump <NUM>.

Claim 1:
Apparatus for delivering a fluid to a subject through infusion tubing (<NUM>), the apparatus comprising:
(A) a tube cassette (<NUM>) configured to receive the infusion tubing (<NUM>) and comprising an anti-free-flow valve (<NUM>) configured to:
(i) occlude the infusion tubing (<NUM>), and
(ii) be actuated by a force external to the tube cassette (<NUM>) to terminate the occlusion of the infusion tubing (<NUM>); and
(B) a pump (<NUM>), with the tube cassette (<NUM>) being configured to be removably coupled to the pump (<NUM>), and
characterised in that:
the pump (<NUM>) is configured to, as part of a pumping cycle for delivering the fluid to the subject, repeatedly (a) actuate the anti-free-flow valve (<NUM>) to terminate the occlusion of the infusion tubing (<NUM>), and subsequently (b) release the anti-free-flow valve (<NUM>) to occlude the infusion tubing (<NUM>).