WO2005002642A2 - Medication infusion device using negatively biased ambient pressure medication chamber - Google Patents

Medication infusion device using negatively biased ambient pressure medication chamber Download PDF

Info

Publication number
WO2005002642A2
WO2005002642A2 PCT/US2004/020117 US2004020117W WO2005002642A2 WO 2005002642 A2 WO2005002642 A2 WO 2005002642A2 US 2004020117 W US2004020117 W US 2004020117W WO 2005002642 A2 WO2005002642 A2 WO 2005002642A2
Authority
WO
WIPO (PCT)
Prior art keywords
chamber
medication
ambient pressure
wall portion
force
Prior art date
Application number
PCT/US2004/020117
Other languages
French (fr)
Other versions
WO2005002642A3 (en
Inventor
Scott R. Gibson
Peter C. Lord
Original Assignee
Medical Research Products-A, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Medical Research Products-A, Inc. filed Critical Medical Research Products-A, Inc.
Priority to EP04755946.3A priority Critical patent/EP1635894B1/en
Publication of WO2005002642A2 publication Critical patent/WO2005002642A2/en
Publication of WO2005002642A3 publication Critical patent/WO2005002642A3/en
Priority to US11/294,973 priority patent/US8070745B2/en
Priority to US13/287,651 priority patent/US8932253B2/en

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
    • A61M5/142—Pressure infusion, e.g. using pumps
    • A61M5/14244—Pressure infusion, e.g. using pumps adapted to be carried by the patient, e.g. portable on the body
    • A61M5/14276—Pressure infusion, e.g. using pumps adapted to be carried by the patient, e.g. portable on the body specially adapted for implantation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
    • A61M5/142—Pressure infusion, e.g. using pumps
    • A61M5/145—Pressure infusion, e.g. using pumps using pressurised reservoirs, e.g. pressurised by means of pistons
    • A61M5/14586—Pressure infusion, e.g. using pumps using pressurised reservoirs, e.g. pressurised by means of pistons pressurised by means of a flexible diaphragm
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
    • A61M5/142—Pressure infusion, e.g. using pumps
    • A61M5/14244—Pressure infusion, e.g. using pumps adapted to be carried by the patient, e.g. portable on the body
    • A61M2005/14264—Pressure infusion, e.g. using pumps adapted to be carried by the patient, e.g. portable on the body with means for compensating influence from the environment
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2205/00—General characteristics of the apparatus
    • A61M2205/02—General characteristics of the apparatus characterised by a particular materials
    • A61M2205/0266—Shape memory materials

Definitions

  • This invention relates generally to medication infusion devices which include a chamber for storing fluid medication and means for extracting medication from the chamber for delivery to a patient's body site.
  • Positive referenced devices have the advantage that the propellant can be selected to provide a constant driving pressure under defined operating conditions (e.g., constant flow applications) acting in a direction to force medication out of the chamber.
  • negative referenced devices have inherent safety advantages; e.g., when refilling the chamber with a hypodermic needle, medication can be drawn into the chamber without the application of manual pressure to the needle. This assures that the needle will not discharge medication unless it has been properly placed in a device fill port and reduces the possibility of chamber overpressurization. Also, during normal operation, since chamber pressure is lower than ambient pressure, the pressure differential acts in a direction to draw fluid from the outlet catheter toward the chamber thus tending to reduce the risk of medication leakage into the patient's body.
  • the present invention is directed to a method and apparatus for infusing medication into a patient's body using a medication chamber referenced to ambient pressure (so as to avoid the need for, and attendant complexity of, a propellant reservoir) while achieving the safety and reliability of negative referenced propellant reservoir designs.
  • Embodiments of the invention can be configured for use either exterior to a patient's body or implanted within a patient's body
  • An apparatus in accordance with the invention includes a medication chamber enclosed by a peripheral (or boundary) member which includes a movable portion configured to transfer exterior ambient pressure into the chamber. Means are provided in accordance with the invention for exerting a negative bias force acting on the movable portion in a direction opposed to the force produced by the ambient pressure.
  • the peripheral member defining the chamber can be variously formed in accordance with the invention.
  • the peripheral member (or wall) can be comprised of one or more rigid and/or flexible wall portions which cooperate to fully enclose the chamber. At least one wall portion is movable and has an exterior surface exposed to ambient pressure.
  • the peripheral member is defined by a rigid wall portion and a flexible wall portion, e.g., a resilient membrane, secured around its edge to the rigid wall portion to enclose the chamber therebetween.
  • the exterior surface of the flexible wall portion is exposed to ambient pressure and a negative bias force is applied to the flexible wall portion acting in opposition to the ambient pressure.
  • the negative bias force can be provided by various types of force generators, e.g., a magnet, the inherent resiliency of a properly configured resilient membrane, or by a spring member (e.g., leaf, coil, bellows, elastomeric material, etc). In any event, the bias force acts to create a pressure in the chamber which is negative with reference to ambient.
  • medication is extracted from the negatively biased chamber by a selectively actuatable outlet pump.
  • the chamber peripheral wall member can be comprised of first and second rigid wall portions connected by a flexible wall portion, e.g., a flexible shroud or bellows, which permits the rigid wall portions to move toward and away from one another to vary the chamber volume therebetween.
  • the chamber peripheral wall can be formed by the interior wall surface of a hollow cylinder and by a piston mounted for reciprocal linear movement in the cylindrical volume. Regardless of the particular implementation of the chamber peripheral wall, embodiments of the invention are characterized by a movable wall portion which is exposed to ambient pressure and a bias force acting in opposition to the ambient pressure to produce a resultant chamber pressure which is negative with respect to the ambient pressure.
  • the chamber peripheral wall including the moveable wall portion, preferably has a geometry which optimizes volumetric efficiency, i.e., maximizes the useable volume and minimizes dead space volume or ullage.
  • the bias force can be produced by a variety of force members including, for example, discrete springs of various types, elastomeric material, magnets, etc.
  • Figure 1 is a schematic plan view of a preferred medication infusion device in accordance with the invention
  • Figure 2 is a schematic sectional view through the device of Figure 1 showing the movable portion (e.g., resilient membrane) of the chamber peripheral (or boundary) wall in a fully extended (i.e., chamber full) position
  • Figure 3 is a schematic representation of the movable chamber wall portion depicting the application of ambient and bias forces to the wall portion in accordance with the invention
  • Figures 4A and 4B schematically depict an alternative embodiment of the invention using a spring to provide the bias and respectively showing the movable wall portion in its compressed and extended positions
  • Figure 5 is a schematic illustration of a further alternative embodiment of the invention using a bellows or exterior spring to provide the bias force
  • Figure 6 is a schematic illustration of a still further alternative embodiment using magnetic repulsion to provide the bias force
  • Figure 7 is a schematic illustration of a still further embodiment using a hollow cylinder and a movable piston to define the chamber.
  • Figures 1 and 2 illustrate a preferred embodiment of a medication device 20 in accordance with the present invention for controllably delivering medication to a patient's body site.
  • the device 20 illustrated in Figures 1 and 2 is intended for implanting in a patient's body, it should be understood that the invention also finds utility in applications where the device is carried externally.
  • the device 20 is comprised of a housing 24 including a base plate 26 and a cover 28 supported on the base plate 26.
  • the base plate 26 and cover 28 define one or more compartments therebetween, e.g., compartments 30, 34, 38 for housing various components such as battery 32, an electronics module 36, and an active medication pump 40.
  • Figure 2 depicts a flexible and resilient membrane 44 secured along its edge 46 to the underside of the base plate 26.
  • the membrane 44 is configured to naturally expand to the fully extended position shown in Figure 2 to maximize the space, i.e., volume, of the closed medication chamber 50 formed between the membrane 44 and base plate surface 47.
  • An inlet valve 54 is supported by the cover 28 and base plate 26 and affords communication to the interior of chamber 50.
  • the inlet valve 54 can be conventionally constructed comprising a self healing septum 56 through which a hypodermic needle can be inserted to discharge medication into the chamber 50.
  • the hypodermic needle when properly inserted through septum 56, is able to discharge medication into the chamber 50 without the application of manual pressure to the hypodermic needle.
  • the active pump 40 has an inlet 60 which communicates with the chamber 50 for extracting medication therefrom.
  • the pump 40 is coupled to a catheter outlet connector 62 through which medication is pumped for distribution to a body site.
  • the membrane 44 comprises a movable portion of a peripheral member or wall which defines and encloses the medication chamber 50.
  • the exterior surface 68 of the membrane 44 is configured to be exposed to ambient pressure, i.e., that is the internal body pressure when the implantable device 20 is in situ. Typically, this ambient pressure will be very close to atmospheric pressure, which of course is dependent upon altitude, temperature, etc.
  • the ambient pressure acts in a direction tending to compress the membrane 44 against the base plate 26. More particularly, when the chamber 50 is filled with medication, the membrane 44 will expand to its natural fully extended position shown in Figure 2. However, when the medication is evacuated by action of pump 40, then the ambient pressure acts to collapse the membrane 44 toward the base plate surface 47.
  • a spring bias force is applied to the chamber movable wall portion, i.e., membrane 44 in Figure 2, which acts in a direction to oppose the ambient pressure force so as to create a residual pressure in the chamber which is negative with reference to ambient.
  • the ambient pressure P A acting on the exterior surface 68 of movable wall portion 44 produces a force F A tending to move the wall portion 44 toward the base plate 26, i.e., to collapse the chamber 50.
  • a bias force F B is created which acts in opposition to the force F A - AS shown, the chamber pressure P c will be negative with respect to the ambient pressure P A attributable to the negative bias force FB.
  • the force F B can be provided in a variety of different ways.
  • the membrane 44 of Figure 2 can comprise a part formed of metal or plastic material (e.g., nitinol, titanium, stainless steel, super alloys, composite material) configured so that in its natural or quiescent state it resiliently expands to the extended position represented in Figures 2 and 3.
  • metal or plastic material e.g., nitinol, titanium, stainless steel, super alloys, composite material
  • a separate force generator e.g., a spring, a magnet, a frictional member, etc. can be incorporated into the device structure.
  • FIG. 4A depicts an alternative embodiment 100.
  • the embodiment 100 includes a base plate 102 and cover 104 which can be considered identical to the corresponding components 26 and 28 discussed in connection with Figure 2.
  • the plate 102 defines a substantially rigid portion of a peripheral wall extending around and enclosing a medication chamber 106.
  • the chamber peripheral wall in accordance with the present invention, also includes a movable portion which in embodiment 100 comprises a flexible boot or shroud 108.
  • the boot 108 carries a rigid wall portion 110 which is spaced from and oriented substantially parallel to plate 102.
  • the chamber 106 in embodiment 100 is defined by the inner surfaces of wall portions 102 and 110 and flexible wall portion or boot 108.
  • a force generator comprises a coil spring 120 mounted between the inner surfaces of wall portions 102 and 110.
  • the spring member 120 is shown as a coil spring which is configured so that in its natural or quiescent state, e.g., in a vacuum, it is extended to the position shown in Figure 4B.
  • Ambient pressure acting on the outer surface of movable portion 110 acts in the direction to compress spring member 120 with the spring member thus providing a restoration or bias force acting in opposition to the force of the ambient pressure.
  • the pressure within the chamber 106 will be maintained below the ambient pressure as a consequence of the force produced by spring 120 as was discussed in connection with Figure 3.
  • this spring force is selected to produce a chamber pressure which is negative with respect to ambient pressure by a differential within the range 0.1 to 5.0 psig.
  • Figure 5 depicts a further alternative embodiment 200 in which the inner surfaces of a base plate 202, a movable rigid portion 204, and a flexible shroud or bellows 206 define and enclose a medication chamber 208.
  • a coil spring 210 is depicted as being formed around the exterior of the shroud 206.
  • the shroud 206 and coil spring 210 be formed separately or alternatively can be formed as an integral bellows member.
  • the embodiment of Figure 5 operates identically to the embodiment of Figures 4A and 4B in that the spring 210 produces a bias force opposing the force of the ambient pressure bearing on wall portion 204.
  • FIG. 6 illustrates an embodiment 300 which is similar in construction to the embodiment 200 in Figure 5.
  • the embodiment 300 uses magnetic repulsion to develop the negative bias force. More particularly, note in Figure 6 that adjacent magnets 302 and 204 are similarly poled. Also note that adjacent magnets 306 and 308 are similarly poled.
  • the force produced by ambient pressure on the exterior surface of wall portion 310 acts to displace wall portion 310 toward base plate 312, the repulsion force produced by the magnets will increase in opposition to the ambient force.
  • this negative bias force will produce a chamber pressure which is negative with respect to the ambient pressure.
  • Figure 7 depicts a still further embodiment 400. In the embodiment of
  • a hollow cylinder 402 is provided defining an interior wall surface 404.
  • a piston 408 is mounted for reciprocal linear motion within the cylindrical volume defined by the interior wall surface 404.
  • An inlet valve 412 opens to the medication chamber and an outlet 414 couples the chamber 410 to an actuatable pump 416.
  • a force generator e.g., spring member 418, is shown mounted in the chamber 410 bearing against piston interior surface 409. The piston outer surface 420 is exposed to ambient pressure.
  • Figure 7 depicts spring 418 in its expanded state with the chamber 410 filled with medication supplied via inlet valve 412.

Abstract

A method and apparatus of infusing medication into a patient's body using a medication chamber referenced to ambient pressure. The apparatus includes a medication chamber (50) enclosed by a peripheral wall (44) which includes a movable portion configured to transfer exterior ambient pressure into the chamber. Means are provided for exerting a negative biasing force acting on the movable portion in a direction opposed to the ambient pressure force. Thus, the resultant pressure in the chamber will be negative with respect to ambient pressure, reducing the risk that the chamber can be overpressurized and produce an unintended medication discharge.

Description

TITLE: MEDICATION INFUSION DEVICE USING NEGATIVELY BIASED AMBIENT PRESSURE MEDICATION CHAMBER
INVENTOR: SCOTT R. GIBSON, PETER C. LORD
F:IELD OF THE INVENTION This invention relates generally to medication infusion devices which include a chamber for storing fluid medication and means for extracting medication from the chamber for delivery to a patient's body site.
BACKGROUND OF THE INVENTION Various types of implantable and/or external medication infusion devices are described in the literature. For example only, see U.S. Patents 4,772,263 and 6,283,943 and the references cited therein which relate primarily to implantable devices. Many such devices employ a medication chamber together with a propellant reservoir which functions to isolate the chamber from changes in ambient pressure attributable, for example, to changes in altitude. More particularly, a typical propellant reservoir contains a biphasic propellant balanced between gas and liquid phases to maintain a constant pressure regardless of changes in reservoir volume. The pressure in the medication chamber is typically referenced (either positive or negative) to the constant reservoir pressure. Positive referenced devices have the advantage that the propellant can be selected to provide a constant driving pressure under defined operating conditions (e.g., constant flow applications) acting in a direction to force medication out of the chamber. Alternatively, negative referenced devices have inherent safety advantages; e.g., when refilling the chamber with a hypodermic needle, medication can be drawn into the chamber without the application of manual pressure to the needle. This assures that the needle will not discharge medication unless it has been properly placed in a device fill port and reduces the possibility of chamber overpressurization. Also, during normal operation, since chamber pressure is lower than ambient pressure, the pressure differential acts in a direction to draw fluid from the outlet catheter toward the chamber thus tending to reduce the risk of medication leakage into the patient's body. Although the use of a propellant reservoir has the advantage of isolating the medication chamber from changes in ambient pressure, it nevertheless adds to device size, complexity, and cost. Accordingly, it has been recognized that, in some situations, it may be preferable to reference the medication chamber directly to ambient pressure. For example, U.S. Patent 4,772,263 describes an infusion pump which includes a spring for producing a positive force on the drug chamber to force the solution therefrom.
SUMMARY OF THE INVENTION The present invention is directed to a method and apparatus for infusing medication into a patient's body using a medication chamber referenced to ambient pressure (so as to avoid the need for, and attendant complexity of, a propellant reservoir) while achieving the safety and reliability of negative referenced propellant reservoir designs. Embodiments of the invention can be configured for use either exterior to a patient's body or implanted within a patient's body An apparatus in accordance with the invention includes a medication chamber enclosed by a peripheral (or boundary) member which includes a movable portion configured to transfer exterior ambient pressure into the chamber. Means are provided in accordance with the invention for exerting a negative bias force acting on the movable portion in a direction opposed to the force produced by the ambient pressure. Thus, the resultant pressure in the chamber will always be negative with respect to ambient pressure, reducing the risk that the chamber can be overpressurized and produce an unintended medication discharge. The peripheral member defining the chamber can be variously formed in accordance with the invention. For example, the peripheral member (or wall) can be comprised of one or more rigid and/or flexible wall portions which cooperate to fully enclose the chamber. At least one wall portion is movable and has an exterior surface exposed to ambient pressure. In one preferred embodiment, the peripheral member is defined by a rigid wall portion and a flexible wall portion, e.g., a resilient membrane, secured around its edge to the rigid wall portion to enclose the chamber therebetween. The exterior surface of the flexible wall portion is exposed to ambient pressure and a negative bias force is applied to the flexible wall portion acting in opposition to the ambient pressure. The negative bias force can be provided by various types of force generators, e.g., a magnet, the inherent resiliency of a properly configured resilient membrane, or by a spring member (e.g., leaf, coil, bellows, elastomeric material, etc). In any event, the bias force acts to create a pressure in the chamber which is negative with reference to ambient. In accordance with the invention, medication is extracted from the negatively biased chamber by a selectively actuatable outlet pump. In one alternative preferred embodiment, the chamber peripheral wall member can be comprised of first and second rigid wall portions connected by a flexible wall portion, e.g., a flexible shroud or bellows, which permits the rigid wall portions to move toward and away from one another to vary the chamber volume therebetween. In a still further preferred embodiment, the chamber peripheral wall can be formed by the interior wall surface of a hollow cylinder and by a piston mounted for reciprocal linear movement in the cylindrical volume. Regardless of the particular implementation of the chamber peripheral wall, embodiments of the invention are characterized by a movable wall portion which is exposed to ambient pressure and a bias force acting in opposition to the ambient pressure to produce a resultant chamber pressure which is negative with respect to the ambient pressure. The chamber peripheral wall, including the moveable wall portion, preferably has a geometry which optimizes volumetric efficiency, i.e., maximizes the useable volume and minimizes dead space volume or ullage. The bias force can be produced by a variety of force members including, for example, discrete springs of various types, elastomeric material, magnets, etc.
BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a schematic plan view of a preferred medication infusion device in accordance with the invention; Figure 2 is a schematic sectional view through the device of Figure 1 showing the movable portion (e.g., resilient membrane) of the chamber peripheral (or boundary) wall in a fully extended (i.e., chamber full) position; Figure 3 is a schematic representation of the movable chamber wall portion depicting the application of ambient and bias forces to the wall portion in accordance with the invention; Figures 4A and 4B schematically depict an alternative embodiment of the invention using a spring to provide the bias and respectively showing the movable wall portion in its compressed and extended positions; Figure 5 is a schematic illustration of a further alternative embodiment of the invention using a bellows or exterior spring to provide the bias force; Figure 6 is a schematic illustration of a still further alternative embodiment using magnetic repulsion to provide the bias force; and Figure 7 is a schematic illustration of a still further embodiment using a hollow cylinder and a movable piston to define the chamber.
DETAILED DESCIPTION Attention is now directed to Figures 1 and 2 which illustrate a preferred embodiment of a medication device 20 in accordance with the present invention for controllably delivering medication to a patient's body site. Although the particular device 20 illustrated in Figures 1 and 2 is intended for implanting in a patient's body, it should be understood that the invention also finds utility in applications where the device is carried externally. As depicted in Figures 1 and 2, the device 20 is comprised of a housing 24 including a base plate 26 and a cover 28 supported on the base plate 26. The base plate 26 and cover 28 define one or more compartments therebetween, e.g., compartments 30, 34, 38 for housing various components such as battery 32, an electronics module 36, and an active medication pump 40. Figure 2 depicts a flexible and resilient membrane 44 secured along its edge 46 to the underside of the base plate 26. As will be explained in greater detail hereinafter, the membrane 44 is configured to naturally expand to the fully extended position shown in Figure 2 to maximize the space, i.e., volume, of the closed medication chamber 50 formed between the membrane 44 and base plate surface 47. When the content of chamber 50 is evacuated, the ambient pressure acting against the membrane 44 will collapse it against base plate surface 47. An inlet valve 54 is supported by the cover 28 and base plate 26 and affords communication to the interior of chamber 50. The inlet valve 54 can be conventionally constructed comprising a self healing septum 56 through which a hypodermic needle can be inserted to discharge medication into the chamber 50. As will be discussed hereinafter, inasmuch as the medication chamber 50, in accordance with the present invention, is maintained at a negative pressure relative to ambient pressure, the hypodermic needle, when properly inserted through septum 56, is able to discharge medication into the chamber 50 without the application of manual pressure to the hypodermic needle. The active pump 40 has an inlet 60 which communicates with the chamber 50 for extracting medication therefrom. The pump 40 is coupled to a catheter outlet connector 62 through which medication is pumped for distribution to a body site. In accordance with the present invention, the membrane 44 comprises a movable portion of a peripheral member or wall which defines and encloses the medication chamber 50. The exterior surface 68 of the membrane 44 is configured to be exposed to ambient pressure, i.e., that is the internal body pressure when the implantable device 20 is in situ. Typically, this ambient pressure will be very close to atmospheric pressure, which of course is dependent upon altitude, temperature, etc. The ambient pressure acts in a direction tending to compress the membrane 44 against the base plate 26. More particularly, when the chamber 50 is filled with medication, the membrane 44 will expand to its natural fully extended position shown in Figure 2. However, when the medication is evacuated by action of pump 40, then the ambient pressure acts to collapse the membrane 44 toward the base plate surface 47. In accordance with the present invention, a spring bias force is applied to the chamber movable wall portion, i.e., membrane 44 in Figure 2, which acts in a direction to oppose the ambient pressure force so as to create a residual pressure in the chamber which is negative with reference to ambient. More particularly, with reference to Figure 3, note that the ambient pressure PA acting on the exterior surface 68 of movable wall portion 44 produces a force FA tending to move the wall portion 44 toward the base plate 26, i.e., to collapse the chamber 50. In accordance with the present invention, a bias force FB is created which acts in opposition to the force FA- AS shown, the chamber pressure Pc will be negative with respect to the ambient pressure PA attributable to the negative bias force FB. The force FB can be provided in a variety of different ways. For example, the membrane 44 of Figure 2 can comprise a part formed of metal or plastic material (e.g., nitinol, titanium, stainless steel, super alloys, composite material) configured so that in its natural or quiescent state it resiliently expands to the extended position represented in Figures 2 and 3. Thus, as the ambient pressure bears against, the movable wall portion of membrane 44 tending to move it toward its compressed position, it will develop a restoration force FB acting to oppose the compression. As an alternative to configuring wall portion 44 to inherently exhibit the desired resilient characteristic, a separate force generator, e.g., a spring, a magnet, a frictional member, etc. can be incorporated into the device structure. Attention is now directed to Figure 4A which depicts an alternative embodiment 100. The embodiment 100 includes a base plate 102 and cover 104 which can be considered identical to the corresponding components 26 and 28 discussed in connection with Figure 2. The plate 102 defines a substantially rigid portion of a peripheral wall extending around and enclosing a medication chamber 106. The chamber peripheral wall, in accordance with the present invention, also includes a movable portion which in embodiment 100 comprises a flexible boot or shroud 108. The boot 108 carries a rigid wall portion 110 which is spaced from and oriented substantially parallel to plate 102. Thus, the chamber 106 in embodiment 100 is defined by the inner surfaces of wall portions 102 and 110 and flexible wall portion or boot 108. In the embodiment 100, a force generator, or member, comprises a coil spring 120 mounted between the inner surfaces of wall portions 102 and 110. The spring member 120 is shown as a coil spring which is configured so that in its natural or quiescent state, e.g., in a vacuum, it is extended to the position shown in Figure 4B. Ambient pressure acting on the outer surface of movable portion 110 acts in the direction to compress spring member 120 with the spring member thus providing a restoration or bias force acting in opposition to the force of the ambient pressure. Thus, the pressure within the chamber 106 will be maintained below the ambient pressure as a consequence of the force produced by spring 120 as was discussed in connection with Figure 3. Typically, this spring force is selected to produce a chamber pressure which is negative with respect to ambient pressure by a differential within the range 0.1 to 5.0 psig. Figure 5 depicts a further alternative embodiment 200 in which the inner surfaces of a base plate 202, a movable rigid portion 204, and a flexible shroud or bellows 206 define and enclose a medication chamber 208. A coil spring 210 is depicted as being formed around the exterior of the shroud 206. The shroud 206 and coil spring 210 be formed separately or alternatively can be formed as an integral bellows member. The embodiment of Figure 5 operates identically to the embodiment of Figures 4A and 4B in that the spring 210 produces a bias force opposing the force of the ambient pressure bearing on wall portion 204. As medication is drawn from the chamber 208 by action of the active pump, the ambient pressure will displace wall portion 204 toward support plate 202 acting against the bias force provided by spring 210. Figure 6 illustrates an embodiment 300 which is similar in construction to the embodiment 200 in Figure 5. However, in lieu of using a spring member to provide the negative bias force, the embodiment 300 uses magnetic repulsion to develop the negative bias force. More particularly, note in Figure 6 that adjacent magnets 302 and 204 are similarly poled. Also note that adjacent magnets 306 and 308 are similarly poled. Thus, as the force produced by ambient pressure on the exterior surface of wall portion 310 acts to displace wall portion 310 toward base plate 312, the repulsion force produced by the magnets will increase in opposition to the ambient force. Of course, as has been discussed in connection with the earlier embodiments, this negative bias force will produce a chamber pressure which is negative with respect to the ambient pressure. Figure 7 depicts a still further embodiment 400. In the embodiment of
Figure 7, a hollow cylinder 402 is provided defining an interior wall surface 404. A piston 408 is mounted for reciprocal linear motion within the cylindrical volume defined by the interior wall surface 404. The piston 408 interior surface 409, together with wall surface 404, defines a medication chamber 410. An inlet valve 412 opens to the medication chamber and an outlet 414 couples the chamber 410 to an actuatable pump 416. A force generator, e.g., spring member 418, is shown mounted in the chamber 410 bearing against piston interior surface 409. The piston outer surface 420 is exposed to ambient pressure. Figure 7 depicts spring 418 in its expanded state with the chamber 410 filled with medication supplied via inlet valve 412. As medication is extracted from the chamber 410 by action of the pump 416, ambient pressure acting on the piston outer surface 420 will act to move the piston 408 along the interior wall surface 404 to compress spring 418 and diminish the volume of chamber 410. This action will be opposed by the restoration force of spring member 418 thus producing a pressure in chamber 410 which is negative with respect to the ambient pressure applied to the piston surface 420. From the foregoing, it should now be appreciated that multiple exemplary embodiments have been described herein characterized by a chamber peripheral wall portion which is exposed to ambient pressure together with means for producing a bias force acting in opposition to the ambient pressure to produce a pressure within the chamber which is negative with respect to the ambient pressure. Although only a limited number of embodiments have been specifically described, it should be recognized by those skilled in the art that the invention can be implemented by a variety of alternative, essentially equivalent, structures conforming to the spirit of the invention and within the intended scope of the appended claims. // // // // // // // // // // //

Claims

CLAIMS 1. A device for storing medication and for selectively discharging medication for application to a patient's body, said device including: a peripheral member enclosing a chamber suitable for storing medication; said peripheral member including a wall portion configured for transferring exterior ambient pressure into said chamber; bias means for exerting a force on said wall portion acting in opposition to the force produced by said ambient pressure to produce a resultant pressure in said chamber which is negative with respect to said ambient pressure; and an actuatable pump coupled to said chamber for extracting medication from said chamber for infusion into a patient's body.
2. The device of claim 1 wherein said wall portion is configured for movement to vary the volume of said chamber.
3. The device of claim 1 further including a support plate and wherein said wall portion comprises a flexible membrane mounted on said support plate to define said chamber therebetween.
4. The device of claim 3 wherein said flexible membrane exhibits resiliency characterized by a restoration force acting in opposition to the force produced by said ambient pressure on said wall portion..
5. The device of claim 3 wherein said flexible membrane comprises a substantially planar elastic sheet.
6. The device of claim 3 wherein said flexible membrane comprises a bellows.
7. The device of claim 1 wherein said bias means includes a spring bearing against said wall portion.
8. The device of claim 1 wherein said bias means includes spaced magnets oriented to repel.
9. The device of claim 1 wherein said actuatable pump is electrically powered.
//
//
//
// //
//
//
//
// //
//
//
//
// //
//
//
//
// //
//
//
//
// //
//
//
//
//
10. A method of storing fluid medication for selective infusion into a patient's body, said method comprising: providing a peripheral wall for enclosing a chamber suitable for storing medication; exposing an exterior surface of a portion of said wall to ambient pressure for transferring said ambient pressure into said chamber; and applying a bias force to said wall portion acting to oppose the force produced by said ambient pressure for creating a resultant pressure in said chamber which is negative with respect to said ambient pressure.
11. The method of claim 10 further including pumping medication from said chamber for infusion into a patient's body.
//
// //
//
//
//
// //
//
//
//
// //
//
//
//
// //
//
//
//
12. A medication infusion device suitable for implantation in a patient's body, said device comprising: a medication chamber including an interior volume bounded by a peripheral wall; a pump coupled to said interior volume actuatable to extract medication therefrom for delivery to a patient's body site; said peripheral wall including a portion configured for exposure to exterior ambient pressure for producing an interiorly directed ambient pressure force component against said wall portion; and means for exerting a bias force component on said wall portion directed oppositely to said inwardly directed force component for producing a resultant pressure in said interior volume which is negative with respect to said ambient pressure
13. The device of claim 12 wherein said wall portion is configured to move in response to a difference in magnitude between said ambient pressure force component and said bias force component.
14. The device of claim 12 wherein said means for exerting a bias force includes a spring.
15. The device of claim 12 wherein said medication chamber includes an inlet port for supplying medication to said interior volume.
// //
//
//
//
// //
//
//
//
//
PCT/US2004/020117 2003-06-25 2004-06-23 Medication infusion device using negatively biased ambient pressure medication chamber WO2005002642A2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP04755946.3A EP1635894B1 (en) 2003-06-25 2004-06-23 Medication infusion device using negatively biased ambient pressure medication chamber
US11/294,973 US8070745B2 (en) 2003-06-25 2005-12-06 Medication infusion device using negatively biased ambient pressure medication chamber
US13/287,651 US8932253B2 (en) 2003-06-25 2011-11-02 Medication infusion device using negatively biased ambient pressure medication chamber

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US48301503P 2003-06-25 2003-06-25
US60/483,015 2003-06-25

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US11/294,973 Continuation US8070745B2 (en) 2003-06-25 2005-12-06 Medication infusion device using negatively biased ambient pressure medication chamber

Publications (2)

Publication Number Publication Date
WO2005002642A2 true WO2005002642A2 (en) 2005-01-13
WO2005002642A3 WO2005002642A3 (en) 2005-02-24

Family

ID=33563902

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2004/020117 WO2005002642A2 (en) 2003-06-25 2004-06-23 Medication infusion device using negatively biased ambient pressure medication chamber

Country Status (3)

Country Link
US (2) US8070745B2 (en)
EP (1) EP1635894B1 (en)
WO (1) WO2005002642A2 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2050476A2 (en) 2005-05-26 2009-04-22 Infusion Systems, LLC Implantable infusion device with multiple controllable fluid outlets
WO2009085407A1 (en) * 2007-12-27 2009-07-09 Medtronic Minimed, Inc. Reservoir pressure equalization systems and methods
US8221354B2 (en) 2006-04-27 2012-07-17 Medtronic, Inc. Infusion device with positive pressure elastic bladder reservoir
WO2012103544A2 (en) 2011-01-28 2012-08-02 Brett Carter Detachable drug delivery device
US8721605B2 (en) 2009-04-27 2014-05-13 The Alfred E. Mann Foundation For Scientific Research Implantable infusion devices with palpable landmarks and methods of needle detection

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005002642A2 (en) 2003-06-25 2005-01-13 Medical Research Products-A, Inc. Medication infusion device using negatively biased ambient pressure medication chamber
EP2617364B1 (en) * 2012-01-19 2014-06-04 Stryker Trauma GmbH Surgical instrument for positioning a sleeve
EP2623142A1 (en) * 2012-02-01 2013-08-07 Debiotech S.A. Medical liquid injection device having improved emptying detection features
EP3258988B1 (en) 2015-02-17 2019-08-28 Amgen Inc. Drug delivery device with vacuum assisted securement and/or feedback
US11147918B2 (en) * 2018-10-23 2021-10-19 Medtronic, Inc. Needle insertion responsive system
US11744939B2 (en) 2020-10-29 2023-09-05 Medtronic, Inc. Cyclic intrathecal drug delivery system and biomarker monitoring

Family Cites Families (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3831203A (en) * 1973-09-28 1974-08-27 Atomic Energy Commission Implantable blood pumping system
US4265241A (en) * 1979-02-28 1981-05-05 Andros Incorporated Implantable infusion device
US4360019A (en) * 1979-02-28 1982-11-23 Andros Incorporated Implantable infusion device
US4573994A (en) * 1979-04-27 1986-03-04 The Johns Hopkins University Refillable medication infusion apparatus
DE3138320A1 (en) * 1981-09-25 1983-04-14 Siemens AG, 1000 Berlin und 8000 München INFUSION DEVICE PROVIDED FOR IMPLANTATION IN A LIVING BODY
US4661097A (en) * 1984-06-01 1987-04-28 The Johns Hopkins University Method for clearing a gas bubble from a positive displacement pump contained within a fluid dispensing system
US4714462A (en) * 1986-02-03 1987-12-22 Intermedics Infusaid, Inc. Positive pressure programmable infusion pump
US4718893A (en) * 1986-02-03 1988-01-12 University Of Minnesota Pressure regulated implantable infusion pump
US4772263A (en) * 1986-02-03 1988-09-20 Regents Of The University Of Minnesota Spring driven infusion pump
US4717762A (en) * 1986-09-08 1988-01-05 Honeywell Inc. Electroactive polymers having aromatic and quinonoid bonding structures
US4781689A (en) * 1986-11-13 1988-11-01 Andrew Sealfon Spring-operated liquid-dispensing device
US4838887A (en) * 1987-12-15 1989-06-13 Shiley Infusaid Inc. Programmable valve pump
US5336188A (en) * 1989-06-16 1994-08-09 Science Incorporated Fluid delivery apparatus having a stored energy source
US5045064A (en) * 1990-06-01 1991-09-03 Infusaid, Inc. Constant pressure implantable pump reservoir
US5334197A (en) * 1990-09-25 1994-08-02 Science Incorporated Flexible base fluid delivery apparatus
US5176641A (en) * 1991-07-08 1993-01-05 Infusaid, Inc. Implantable drug infusion reservoir having fluid impelling resilient foam member
US5306257A (en) * 1992-05-04 1994-04-26 Prime Medical Products, Inc. Drug infuser
US5281210A (en) * 1992-09-18 1994-01-25 Infusaid, Inc. Accumulator for implantable pump
SE9400821D0 (en) * 1994-03-10 1994-03-10 Siemens Elema Ab Implantable infusion system with pressure neutral drug container
US5665070A (en) * 1995-01-19 1997-09-09 I-Flow Corporation Infusion pump with magnetic bag compression
US5976109A (en) * 1996-04-30 1999-11-02 Medtronic, Inc. Apparatus for drug infusion implanted within a living body
AU2214600A (en) * 1998-12-29 2000-07-31 Mckinley Medical, Lllp Spring-powered infusion pump
US6283943B1 (en) * 1999-02-19 2001-09-04 Minimed Inc. Negative pressure pump
WO2000074751A1 (en) * 1999-06-08 2000-12-14 Medical Research Group, Inc. Method and apparatus for infusing liquids using a chemical reaction in an implanted infusion device
US6216916B1 (en) * 1999-09-16 2001-04-17 Joseph S. Kanfer Compact fluid pump
US6666845B2 (en) * 2001-01-04 2003-12-23 Advanced Neuromodulation Systems, Inc. Implantable infusion pump
US6652510B2 (en) * 2001-09-07 2003-11-25 Medtronic Minimed, Inc. Implantable infusion device and reservoir for same
US7052251B2 (en) * 2002-04-22 2006-05-30 Medtronic Minimed, Inc. Shape memory alloy wire driven positive displacement micropump with pulsatile output
WO2003099351A2 (en) * 2002-05-22 2003-12-04 Medical Research Products-A, Inc. Implantable medication delivery device
WO2005002642A2 (en) 2003-06-25 2005-01-13 Medical Research Products-A, Inc. Medication infusion device using negatively biased ambient pressure medication chamber
US20050087555A1 (en) * 2003-10-28 2005-04-28 Hatton Jason D. Fluid dispensing components

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
None
See also references of EP1635894A4

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2050476A2 (en) 2005-05-26 2009-04-22 Infusion Systems, LLC Implantable infusion device with multiple controllable fluid outlets
US8808243B2 (en) 2005-05-26 2014-08-19 Medallion Therapeutics, Inc. Implantable infusion device with multiple controllable fluid outlets
EP2050476A3 (en) * 2005-05-26 2009-09-16 Infusion Systems, LLC Implantable infusion device with multiple controllable fluid outlets
US8002747B2 (en) 2005-05-26 2011-08-23 The Alfred E. Mann Foundation For Scientific Research Implantable infusion device with multiple controllable fluid outlets
US8221354B2 (en) 2006-04-27 2012-07-17 Medtronic, Inc. Infusion device with positive pressure elastic bladder reservoir
US9598210B2 (en) 2007-12-27 2017-03-21 Medtronic Minimed, Inc. Reservoir pressure equalization systems and methods
US8313467B2 (en) 2007-12-27 2012-11-20 Medtronic Minimed, Inc. Reservoir pressure equalization systems and methods
US10391239B2 (en) 2007-12-27 2019-08-27 Medtronic Minimed, Inc. Reservoir pressure equalization systems and methods
US8753326B2 (en) 2007-12-27 2014-06-17 Medtronic Minimed, Inc. Reservoir pressure equalization systems and methods
US8764723B2 (en) 2007-12-27 2014-07-01 Medtronic Minimed, Inc. Reservoir pressure equalization systems and methods
WO2009085407A1 (en) * 2007-12-27 2009-07-09 Medtronic Minimed, Inc. Reservoir pressure equalization systems and methods
US9981117B2 (en) 2009-04-27 2018-05-29 Medallion Therapeutics, Inc. Implantable infusion devices and associated methods
US8721605B2 (en) 2009-04-27 2014-05-13 The Alfred E. Mann Foundation For Scientific Research Implantable infusion devices with palpable landmarks and methods of needle detection
CN103619382A (en) * 2011-01-28 2014-03-05 凯利宝医疗公司 Detachable drug delivery device
AU2012211080B2 (en) * 2011-01-28 2016-08-25 Calibra Medical, Inc. Detachable drug delivery device
EP2667917A4 (en) * 2011-01-28 2014-08-27 Calibra Medical Inc Detachable drug delivery device
WO2012103544A2 (en) 2011-01-28 2012-08-02 Brett Carter Detachable drug delivery device
EP2667917A2 (en) * 2011-01-28 2013-12-04 Calibra Medical, Inc. Detachable drug delivery device

Also Published As

Publication number Publication date
US8932253B2 (en) 2015-01-13
US8070745B2 (en) 2011-12-06
WO2005002642A3 (en) 2005-02-24
US20120130353A1 (en) 2012-05-24
US20060089620A1 (en) 2006-04-27
EP1635894A4 (en) 2009-01-14
EP1635894A2 (en) 2006-03-22
EP1635894B1 (en) 2015-05-27

Similar Documents

Publication Publication Date Title
US8070745B2 (en) Medication infusion device using negatively biased ambient pressure medication chamber
JP2665398B2 (en) Implantable drug infusion reservoir
US5167633A (en) Liquid-vapor pressure reservoir for medication infusion pump
EP1509278B1 (en) Implantable medication delivery device
US5176644A (en) Medication infusion pump with improved liquid-vapor pressure reservoir
US7981107B2 (en) Low profile inlet valve for a piston pump therapeutic substance delivery device
US7066915B2 (en) Low profile inlet valve for a piston pump therapeutic substance delivery device
US7288085B2 (en) Permanent magnet solenoid pump for an implantable therapeutic substance delivery device
JP3571804B2 (en) Medication infusion pump with improved pressure reservoir
EP0209677A1 (en) Electrochemically-driven pulsatile drug dispenser
JP2003501156A (en) Liquid injection method and device using chemical reaction in implantable injection device
WO2006108775A2 (en) Pump assembly with active and passive valve
WO1997007840A1 (en) Implantable drug delivery apparatus
EP1385562A1 (en) Implantable therapeutic substance delivery device having a piston pump with an anti-cavitation valve
US7896866B1 (en) System and method for making an implantable pump thinner
US20230127855A1 (en) Implantable electromagnetic pumps

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 11294973

Country of ref document: US

WWE Wipo information: entry into national phase

Ref document number: 2004755946

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 2004755946

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 11294973

Country of ref document: US