Electromagnetically controlled tissue cavity distending system

• US 20060052666A1
• Filed: 09/01/2005
• Published: 03/09/2006
• Est. Priority Date: 09/03/2004
• Status: Active Grant

• Current Assignee: Alka Kumar, Atul Kumar
• Original Assignee: Alka Kumar, Atul Kumar
• Inventors: Kumar, Alka, Kumar, Atul
• Granted Patent: US 8,308,726 B2
• Time in Patent Office: Days
• US Class Current: 600/159
• CPC Class Codes: A61B 1/015 Control of fluid supply or evacuation
• CPC Class Codes: A61M 1/77 Suction-irrigation systems aspiration tips supplying fluids A61M1/85; specific for negative pressure wound therapy A61M1/92; combined with tracheal tubes A61M16/0463
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 29/00 Dilators with or without means for introducing media, e.g. remedies instruments for performing visual medical inspections of cavities or tubes of the body A61B1/00
• CPC Class Codes: A61M 3/0202 with electronic control means or interfaces
• CPC Class Codes: A61M 3/0216 Pressure
• CPC Class Codes: A61M 3/0258 by means of electric pumps
• CPC Class Codes: A61M 31/00 Devices for introducing or retaining media, e.g. remedies, in cavities of the body A61M25/00 takes precedence ; introducing or retaining ophthalmic products into the ocular cavities A61F9/0008

Abstract

A system to minimize fluid turbulence inside a tissue cavity during endoscopic procedures. A body tissue cavity of a subject is distended by continuous flow irrigation using a solenoid operated pump on the inflow side and a positive displacement pump, such as a peristaltic pump, on the outflow side, such that the amplitude of the pressure pulsations created by the outflow positive displacement pump inside the said tissue cavity is substantially dampened to almost negligible levels. The present invention also provides a method for accurately determining the rate of fluid loss into the subject'"'"'s body system during any endoscopic procedure without utilizing any deficit weight or fluid volume calculation, the same being accomplished by using two fluid flow rate sensors. The present invention also provides a system of creating and maintaining any desired pressure in a body tissue cavity for any desired cavity outflow rate.

Claims

1. A system for distending body tissue cavities of subjects by continuous flow irrigation during endoscopic procedures the said system comprising:

a syringe shaped fluid source reservoir containing a non viscous physiologic fluid meant for cavity distension;

an outlet port of the syringe shaped fluid source reservoir being connectable to an inflow port of an endoscope instrument via an inflow tube for dispensing the fluid at a controlled flow rate into the cavity, the flow rate at which the fluid enters into the cavity being termed as the cavity inflow rate;

an inflow pressure transducer being located anywhere in the inflow tube for measuring the fluid pressure inside the cavity,

an outflow port of the endoscope being connectable to an inlet end of a variable speed positive displacement outflow pump through an outflow tube for removing the fluid from the cavity at a controlled flow rate, the flow rate of the said outflow pump being termed as the cavity outflow rate, and

an outlet end of the outflow pump being connected to a waste fluid collecting container through a waste fluid carrying tube,

characterized in that the syringe shaped fluid source reservoir comprises of a hallow barrel for holding the fluid, a plunger mechanism mounted slidably inside the barrel for dispensing the fluid and the plunger being provided with an electromagnetic means for slidably moving the plunger mechanism in a to and fro direction inside the barrel.

2. A system as claimed in claim 1, wherein a proximal end of the inflow tube is connected to the outlet port of the syringe shaped fluid source reservoir and a distal end of the inflow tube being connectable to the inflow port of the endoscope instrument.

3. A system as claimed in claim 1, wherein the inflow pressure transducer is located sufficiently away from the cavity site, preferably near the outlet port of the syringe shaped fluid source reservoir from the practical point of view, such that the actual pressure inside the cavity is measured.

4. A system as claimed in claim 1, wherein a proximal end of the outflow tube being connectable to the outlet port of the endoscope instrument and a distal end of the outflow tube is connected to an inlet end of the variable speed positive displacement outflow pump.

5. A system as claimed in claim 1, wherein the variable speed positive displacement outflow pump is selected from the group comprising peristaltic pump, piston pump, gear pump and diaphragm pump.

6. A system as claimed in claim 5, wherein the variable speed positive displacement outflow pump is a peristaltic pump.

7. A system as claimed in claim 1, wherein the syringe shaped fluid source reservoir comprises a hollow barrel with a proximal open end and a partially closed distal end forming an outlet port;

a plunger mechanism comprising a piston and a magnetic rod being slidably provided inside the barrel and the electro magnetic means comprising a coil made of insulated conducting wire being loosely wound around the magnetic rod.

8. A system as claimed in claim 7, wherein the coil is connected to a DC current supplying means.

9. A system as claimed in claim 1, further comprising a microcontroller electrically coupled to the inflow pressure transducer, the outflow positive displacement pump and the electro magnetic means for controlling the cavity inflow and cavity outflow rates.

10. A system as claimed in claim 1, further comprising an inflow housing tube having a controllable constriction site, a distal end of the same being connected to the inflow tube to provide an exit route for any excess fluid present inside the tissue cavity or being dispensed by the syringe shaped fluid source reservoir, thereby minimizing turbulence inside the body tissue cavity and maintaining the body tissue cavity pressure at a stable value despite physiological contractions of the body tissue cavity wall.

11. A system as claimed in claim 10, wherein the inflow housing tube is releasably connected on the inflow tube to enable replacement of the housing tube with yet another housing tube having a different diameter at the constriction site to suit the operational need of the endoscopic procedure.

12. A system as claimed in claim 10, wherein a distal end of the inflow housing tube is connected to the inflow tube near its proximal end close to the outlet port of the syringe shaped fluid source reservoir.

13. A system as claimed in claim 10, wherein a proximal end of the inflow housing tube empties directly into a excess fluid collecting container and is constantly and completely immersed in the said container.

14. A system as claimed in claim 10, wherein the inflow housing tube is provided with a clamping means at the constriction site to enable the user to vary the diameter of the housing tube at the constriction site to suit the operational needs of endoscopic procedures.

15. A system as claimed in claim 10, wherein the inflow housing tube is provided with an electromechanical device, a solenoid, to enable the micro-controller to vary the diameter of the constriction site.

16. A system as claimed in claim 10, wherein the diameter of the inflow housing tube at the constriction site is in the range of 0.001 mm to a maximum value which is less than the overall diameter of the rest of the housing tube

17. A system as claimed in claim 10, wherein the diameter of the inflow housing tube at the constriction site is in the range of 0.01 to 2.5 mm.

18. A system as claimed in any of claims 1 to 17 further comprising a fluid replenishing container connected to the syringe shaped fluid source reservoir for refilling the fluid source reservoir.

19. A system as claimed in claim 13, wherein the excess fluid collecting container is optionally connected to the syringe shaped fluid reservoir for reusing the fluid collected in the excess fluid collecting container.

20. A system as claimed in claim 18, wherein the fluid replenishing container or the excess fluid collecting container is connected to the syringe shaped fluid reservoir by a fluid supply tube.

21. A system as claimed in claim 18, wherein the fluid replenishing container or the excess fluid collecting container is connected to the syringe shaped fluid reservoir via a replenishment pump and a fluid supply control valve.

22. A system as claimed in claim 1, wherein an inflow fluid controlling valve is provided on the inflow tube for preventing the fluid from entering into the tissue cavity during fluid replenishment phase.

23. A system as claimed in claim 1, wherein the replenishment pump, the fluid supply control valve and the inflow fluid controlling valve are optionally coupled to the microcontroller.

24. A system as claimed in claim 1, further comprising an outflow pressure transducer connected between a proximal end of the outflow tube and the inlet end of the variable speed positive displacement outflow pump for measuring the pressure in the outflow tube.

25. A system as claimed in claim 24, wherein the outflow pressure transducer is optionally electrically coupled to the microcontroller.

26. A system as claimed in claim 1, further comprising an outflow housing tube having a variable size constriction site being provided between the outflow tube and the waste fluid reservoir.

27. A system as claimed in claim 26, wherein a proximal end of the outflow housing tube is connected to the outflow tube near the inlet of the outflow pump.

28. A system as claimed in claim 26, wherein a distal end of the outflow housing tube is connected to the waste fluid carrying tube or to the waste fluid collecting reservoir.

29. A system as claimed in claim 1, wherein the outflow peristaltic pump is provided with 1 to 5 peristaltic pump tubes connected in parallel between the inflow and the outflow ends of the peristaltic pump for reducing the frequency of pressure pulsation, the said tubes being connected to each other at the inflow and the outflow ends of the peristaltic pump and the said peristaltic pump tubes being the ones which come in contact with the rollers of the peristaltic pump.

30. A system as claimed in claim 1, further comprising an outflow pressure pulsation dampening means connected to the outflow tube for dampening the pressure pulsations inside the body tissue cavity caused by the outflow peristaltic pump.

31. A system as claimed in claim 30, wherein the outflow pressure variation dampening means comprises a single outlet syringe mechanism, the piston of the same being coupled synchronously to the positive displacement outflow pump through a coupling means and the single outlet end of the said syringe mechanism being connected to the outflow tube.

32. A system as claimed in claim 1 further comprising a fluid inflow rate sensor connected to the inflow tube.

33. A system as claimed in claim 32, wherein the fluid inflow rate sensor is located in the lumen or wall of the inflow tube for measuring the cavity inflow rate.

34. A system as claimed in claim 1, further comprising a fluid outflow rate sensor connected to the outflow tube.

35. A system as claimed in claim 34, wherein the fluid outflow rate sensor is connected between the proximal end of the outflow tube and the inlet end of the variable speed positive displacement outflow pump for measuring the cavity outflow rate.

36. A system as claimed in claim 34, wherein the fluid outflow rate sensor is located in the lumen or wall of the outflow tube for measuring the cavity outflow rate.

37. A system as claimed in claim 32, wherein the fluid inflow and the outflow rate sensors consist of a heating coil in physical contact with a metal plate for heating the same and a temperature sensor placed in contact with the metal plate for measuring the temperature of the said metal plate, the temperature of the metal plate being a function of the fluid flow rate.

38. A system as claimed in claim 37, wherein the fluid rate flow sensor is a hot wire anemometer.

39. A system as claimed in claim 32, wherein instantaneous real time rate of fluid intravasation is determined by electrically connecting the inflow and outflow fluid flow rate sensors to a micro-controller.

40. A system as claimed in claim 1, wherein the fluid supply tube, the inflow tube, the outflow tube and the waste fluid carrying tube are flexible, disposable and are made of polymeric material.