Interosmolar fluid removal

• US 20090287178A1
• Filed: 12/19/2008
• Published: 11/19/2009
• Est. Priority Date: 05/13/2008
• Status: Active Grant

• Current Assignee: BioInteractions Ltd.
• Original Assignee: Equilibrate, LLC
• Inventors: Herbert, Curtis B.
• Granted Patent: US 8,211,053 B2
• Time in Patent Office: Days
• US Class Current: 604/500
• CPC Class Codes: A61M 2027/004 with at least a part of the circuit outside the body
• CPC Class Codes: A61M 2039/0276 for introducing or removing fluids into or out of the body
• CPC Class Codes: A61M 27/002 Implant devices for drainage of body fluids from one part of the body to another intraocular A61F9/00781; middle ear A61F11/202
• CPC Class Codes: A61M 39/0208 Subcutaneous access sites for injecting or removing fluids transcutaneous access sites A61M39/0247; implantable infusion devices A61M5/14276
• CPC Class Codes: A61M 39/0247 Semi-permanent or permanent transcutaneous or percutaneous access sites to the inside of the body peritoneal dialysis catheters A61M1/285; tracheostomy devices A61M16/0465; measuring pressure within the body A61B5/03; colostomy devices A61F5/445; gastrotomy feeding tubes A61J15/0015; means for fixing a feeding tube outside of the body A61J15/0053

Abstract

There are many medical situations that require removal of fluid from a patient. There are many ways to remove the fluid but many of these situations have not been solved. Herein, inventions are disclosed that generate osmotic pressure that can be used to remove these fluids very effectively, a technique which requires no harsh suction or pumping. One embodiment involves implanting a reservoir that has a semipermeable membrane sidewall. The reservoir contains trapped osmotic solutes that can not pass out through the membrane. But fluid from the patient can flow in. The osmotic pressure from the trapped solutes in the reservoir draws fluid from the patient across the semipermeable membrane and into the device. In some versions, the membrane can be changed as desired during the lifetime of the device by pulling the membrane out through the implanted device and putting a new one back in.

Claims

1. A method of collecting fluids from a patient comprising

placing, in a patient, a fluid collection device that comprises a semipermeable membrane that at least partially bounds a lumen containing trapped osmotic solutes in aqueous solution,

with the lumen being in fluid communication with a transcutaneous port or percutaneous port,

wherein the trapped osmotic solutes

have a molecular weight greater than a molecular weight cutoff of the semipermeable membrane and

create an osmotic pressure that draws physiological fluid from the patient across the membrane and into the lumen.

2. The method of claim 1 wherein the osmotic solutes are present at a concentration to produce the osmotic pressure of between 50 and 100,000 Torr.

3. The method of claim 2 wherein the trapped osmotic solutes have an average molecular weight in a range from about 500 to about 50,000.

4. The method of claim 3 wherein the trapped osmotic solutes are polymers.

5. The method of claim 4 further comprising attaching an external reservoir that also contains the trapped osmotic solutes to the port, with the physiological fluids passing also into the external reservoir.

6. The method of claim 5 wherein the port is integral to the device.

7. The method of claim 5 wherein the port is placed in the patient and the fluid collection device is thereafter passed through the port into the patient.

8. The method of claim 7 wherein the port is part of an internally implanted cage or internal reservoir and the fluid collection device is passed through the port and secured to the cage or reservoir.

9. The method of claim 8 comprising placing the semipermeable membrane of the fluid collection device in a peritoneal space, in an arm, in a leg, or in the patient at or near a lymph node that collects lung fluids.

10. The method of claim 8 wherein the fluid is withdrawn to treat edema or the fluid collection device is at least partially implanted in a peritoneal space and the fluid is withdrawn from the peritoneal space.

11. A medical system for collecting physiological fluid from a patient that comprises:

a semipermeable membrane that at least partially bounds a lumen containing trapped osmotic solutes in aqueous solution,

a transcutaneous port or percutaneous port,

with the lumen being in fluid communication with the transcutaneous port or percutaneous port,

wherein the trapped osmotic solutes

have a molecular weight greater than a molecular weight cutoff of the semipermeable membrane and

have a concentration to create an osmotic pressure to draw physiological fluid from the patient across the semipermeable membrane into the lumen.

12. The system of claim 11 further comprising an external reservoir external to the patient in fluid communication with the port and also containing the trapped osmotic solutes.

13. The system of claim 12 wherein the trapped osmotic solute concentration is more than about 4 millimolar and a molecular weight between about 500 and about 100,000.

15. The system of claim 13 wherein an internally implantable reservoir comprises the lumen and the port is attached to the reservoir.

16. The system of claim 13 wherein the port is attached to an internally implantable cage or reservoir and the semipermeable membrane is part of an insert that is passed through the port and secured to the cage or reservoir.

17. The system of claim 16 wherein the insert is seated in the port.

14. The system of 13 wherein a catheter comprises the lumen.

18. A fluid collection system with a catheter or a needle and an insert that fits into the catheter or needle to create osmotic pressure that draws physiological fluid into the catheter or needed and can be secured therein, the system comprising:

a catheter or needle

an insert that comprises a collar having a bore that opens into a lumen at least partially bounded by a semipermeable membrane

trapped osmotic solutes in the lumen to create osmotic pressure to draw fluids across the membrane into the lumen,

wherein the membrane is joined to the collar, and the insert passes at least partially into the catheter or needle and the insert has a fastener and/or seat that mates with the catheter or needle to secure the insert.

19. The system of claim 18 wherein the insert fastener comprises threads that cooperate with threads on the catheter or needle to secure the insert.

20. The system of claim 19 wherein the semipermeable membrane passes out of a distal end of the catheter or needle when the collar is fastened to the catheter or needle.