Infusion apparatus and method

• US 4,193,397 A
• Filed: 02/05/1979
• Issued: 03/18/1980
• Est. Priority Date: 12/01/1977
• Status: Expired due to Term

• Current Assignee: Strato/Infusaid, Inc.
• Original Assignee: Metal Bellows Corporation
• Inventors: Prosl, Frank R., Tucker, Elton M.
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Rosenbaum, C. F.
• Application Number:
  US06/009,756
• Time in Patent Office: 407 Days
• Field of Search: 128/1 R, 128/172, 128/213 R, 128/214 F, 128/232, 128/260, 128/268, 128/DIG. 12, 3/1
• US Class Current: 604/502
• CPC Class Codes: A61M 2205/353 using mechanical means, e.g. subcutaneous pushbuttons
• CPC Class Codes: A61M 2209/045 for filling, e.g. for filling reservoirs
• CPC Class Codes: A61M 5/14276 specially adapted for implantation

Abstract

An infusion apparatus and method employs an infusate reservoir connected by way of a first flow restrictor to a mixing chamber and a second infusate reservoir connected via a second flow path having a selected restriction characteristic to the same mixing chamber so that infusate may be conveyed to the mixing chamber in different concentrations or in different types. A normally closed valve is provided in the second flow path so that the two infusates supplement one another in the mixing chamber only when the valve is opened. The reservoir and chamber volumes, infusate concentrations and chamber outlet flow rates are dimensioned to provide an integrated dosage profile suited to the patient. The apparatus can also include an accumulator with a restricted inlet in the second flow path situated between the second reservoir and the valve so that when the valve is opened, infusate flows to the mixing chamber from the second flow path only if the accumulator has been replenished from the second reservoir.

Claims

1. Nonelectrical implantable infusion apparatus comprising:

A. a housing;

B. a first collapsible infusate reservoir having an outlet and positioned inside the housing;

C. means for collapsing said first reservoir to expel infusate from its said outlet;

D. a second collapsible infusate reservoir having an outlet and positioned in the housing;

E. means for collapsing said second reservoir to expel infusate from its said outlet;

F. mixing means inside the housing and having a selected volume;

G. a first flow path having a first flow restriction characteristic connected betweem said first reservoir and said mixing means;

H. a second flow path having a second flow restriction characteristic connected between the said second reservoir and the mixing means;

I. a normally closed valve connected in said second flow path so that infusate flows from said second reservoir to the mixing means only when said valve is opened, the infusates from said first and second reservoirs, when said valve is opened, supplementing one another in the mixing means to produce an integrated dosage, and

J. a fluid outlet from said mixing means for conducting said integrated dosage to an infusion site.

7. The apparatus defined in claim 1 wherein said collapsing means comprises a two phase fluid power cell associated with each said reservoir, the fluid in said power cells vaporizing at physiological temperatures.

2. Implantable infusion apparatus comprising:

A. a housing;

B. a first collapsible infusate reservoir having an outlet and positioned inside the housing;

C. means for collapsing said first reservoir to expel infusate from its said outlet;

D. a second collapsible infusate reservoir having an outlet and positioned in the housing;

E. means for collapsing said second reservoir to expel infusate from its said outlet;

F. mixing means;

G. a first flow path having a first flow restriction characteristic connected between said first reservoir and said mixing means;

H. a second flow path having a second flow restriction characteristic connected between said second reservoir and the mixing means, said second flow path restriction characteristic being less restrictive than said first flow path restriction characteristic;

I. a normally closed valve connected in said second flow path so that infusate flows from said second reservoir to the mixing means only when said valve is opened, the infusates from said first and second reservoirs, when said valve is opened, supplementing one another to produce an integrated dosage, and

J. a fluid outlet from said mixing means for conducting said integrated dosage to an infusion site.

3. The apparatus defined in claim 2 wherein said first reservoir contains:

A. a low concentration infusate, and

B. the second reservoir contains a higher concentration infusate.

4. The apparatus defined in claim 3 wherein said second reservoir contains a different fluid than said first reservoir.

5. Implantable infusion apparatus comprising:

A. a housing;

B. a first collapsible infusate reservoir having an outlet and positioned inside the housing;

C. means for collapsing said first reservoir to expel infusate from its said outlet;

D. a second collapsible infusate reservoir having an outlet and positioned in the housing;

E. means for collapsing said second reservoir to expel infusate from its said outlet;

F. mixing means;

G. a first flow path having a first flow restriction characteristic connected between said first reservoir and said mixing means;

H. a second flow path having a second flow restriction characteristic connected between said second reservoir and the mixing means;

I. a normally closed valve connected in said second flow path so that infusate flows from said second reservoir to the mixing means only when said valve is opened, the infusates from said first and second reservoirs, when said valve is opened, supplementing one another to produce an integrated dosage,

J. a fluid outlet from said mixing means for conducting said integrated dosage to an infusion site;

K. a fluid accumulator positioned in the housing and connected in said second fluid flow path upstream from said valve;

L. flow restricting means connected in the second flow, path between the second reservoir and said accumulator, said restricting means having a restriction characteristic which is considerably more restrictive than said first and second flow path restriction characteristics, and

M. said accumulator expelling its contents to said mixing means when said valve is opened so that the integrated dosage is dependent upon the various concentrations and volumetric flow rates.

6. The apparatus defined in claim 5 wherein:

A. the volume of said accumulator is a small percentage of the volume of said second reservoir, and

B. said restricting means permits only a very small flow rate between the second reservoir and the accumulator so that it takes a relatively long time to refill the accumulator from the second reservoir between said valve openings.

8. Implantable infusion apparatus comprising:

A. a housing;

B. a first collapsible infusate reservoir having an outlet and positioned inside the housing;

C. means for collapsing said first reservoir to expel infusate from its said outlet;

D. a second collapsible infusate reservoir having an outlet and positioned in the housing;

E. means for collapsing said second reservoir to expel infusate from its said outlet;

F. mixing means;

G. a first flow path having a first flow restriction characteristic connected between said first reservoir and said mixing means;

H. a second flow path having a second flow restriction characteristic connected between said second reservoir and the mixing means;

I. a normally closed valve connected in said second flow path so that infusate flows from said second reservoir to the mixing means only when said valve is opened, the infusates from said first and second reservoirs, when said valve is opened, supplementing one another to produce an integrated dosage, said valve being mounted in said housing and being accessible from without said housing so that it can be operated manually transcutaneously when the apparatus is implanted subcutaneously and

J. a fluid outlet from said mixing means for conducting said integrated dosage to an infusion site.

9. The apparatus defined in claim 8 wherein said valve comprises:

A. a length of flexible resilient tubing through which fluid flows between said second reservoir and the mixing means when the valve is opened;

B. means normally clamping said tubing preventing fluid flow therethrough, and

C. means for selectively unclamping said clamping means.

10. The apparatus defined in claim 9 wherein the clamping means comprises:

A. a stop member;

B. a first clamp section engaging one side of the tubing;

C. a button;

D. first spring means reacting between the button and the stop member for biasing the first section against the stop member;

E. a second clamp section engaging the opposite side of the tubing, and

F. second spring means biasing the second clamp section toward the first clamp section.

11. Implantable infusion apparatus comprising:

A. a housing;

B. a first collapsible infusate reservoir having an outlet and positioned inside the housing;

C. means for collapsing said first reservoir to expel infusate from its said outlet;

D. a second collapsible infusate reservoir having an outlet and positioned in the housing;

E. means for collapsing said second reservoir to expel infusate from its said outlet;

F. mixing means;

said mixing means comprising a mixing chamber having a selected volume so that an integrated dosage containing a progressively lower percentage of bolus infusate continues to flow to the infusion site for an appreciable time after said valve is closed;

G. a first flow path having a first flow restriction characteristic connected between said first reservoir and said mixing means;

H. a second flow path having a second flow restriction characteristic connected between said second reservoir and the mixing means;

I. a normally closed valve connected in said second flow path so that infusate flows from said second reservoir to the mixing means only when said valve is opened, the infusates from said first and second reservoirs, when said valve is opened, supplementing one another to produce an integrated dosage, and

J. a fluid outlet from said mixing means for conducting said integrated dosage to an infusion site.

12. The apparatus defined in claim 11 wherein the volume of the mixing chamber and the flow rate through said outlet are related so that when said valve is opened and then closed, said integrated dosage of dispensed infusate has a dose rate which falls off more or less expotentially with a selected time constant.

13. Implantable infusion apparatus comprising:

A. a housing;

B. a first collapsible infusate reservoir having an outlet and positioned inside the housing;

C. means for collapsing said first reservoir to expel infusate from its said outlet;

D. a second collapsible infusate reservoir having an outlet and positioned in the housing;

E. means for collapsing said second reservoir to expel infusate from its said outlet;

F. mixing means;

G. a first flow path having a first flow restriction characteristic connected between said first reservoir and said mixing means;

H. a second flow path having a second flow restriction characteristic connected between said second reservoir and the mixing means;

I. a normally closed valve connected in said second flow path so that infusate flows from said second reservoir to the mixing means only when said valve is opened, the infusates from said first and second reservoirs, when said valve is opened, supplementing one another to produce an integrated dosage,

J. a fluid outlet from said mixing means for conducting said integrated dosage to an infusion site, and

K. first and second valved passages leading from the outside of said housing leading respectively to said first and second reservoirs by which said reservoirs may be refilled with infusate.

14. The method of dispensing infusate inside a living body comprising the steps of

A. conducting infusate in a first concentration or type at a first selected flow rate along a first path to a mixing chamber;

B. conducting infusate in a second concentration or type at a second selected flow rate along a second path to said mixing chamber;

C. conducting the infusate from the mixing chamber along a third path to an infusion site in the body;

D. normally blocking the infusate flow from the second path to the chamber;

E. momentarily unblocking the flow from the second path to the chamber at determined time intervals so that in said chamber infusate in the second concentration or type supplements infusate in the first concentration or type providing an integrated dose to the infusion site, and

F. the chamber volume and third path flow rate being related so that when the flow from the second path to the chamber is blocked, the percentage of the second concentration or type infusate in the integrated dose conducted to the infusion site falls off generally expotentially with a selected time constant.

15. The method defined in claim 14 and including the additional step of providing a small volume infusate accumulator having a highly restricted inlet in the second path so that each time the flow from the second path to the chamber is unblocked, essentially the infusate contents of the accumulator flows to said chamber.