WO2004098801A1

WO2004098801A1 - Apparatus and method for cleaning catheters and other hemodynamic devices

Info

Publication number: WO2004098801A1
Application number: PCT/BR2004/000063
Authority: WO
Inventors: Tachibana Toshi-Ichi
Original assignee: Sociedade Brasileira E Japonesa De Beneficência Santa Cruz
Priority date: 2003-05-08
Filing date: 2004-05-10
Publication date: 2004-11-18
Also published as: BR8300685U

Abstract

Apparatus and method for cleaning catheters and other hemodynamic devices comprising a first valve (12) for controlling the water injection, a second valve (17) for controlling the water extraction, a suction pump (19),coupling means (13-14) to a closed cycle balloon tipped catheter (15) or a similar hemodynamic device, timing means (22) and an alternating device (23), wherein the operating method comprises a plurality of washing cycles, each one of said cycles consisting of a first period (t1-t2) during which purified water is introduced by means of positive pressure and a second period (t2-t3) during which the washing water is extracted by means of negative pressure, said first period (t1-t2) being substantially longer than said second period (t2-t3), the negative pressure providing said extraction being approximately equal to 0.4 atmospheres.

Description

APPARATUS AND METHOD FOR CLEANING CATHETERS AND OTHER HEMODYNAMIC DEVICES

Field of the invention

This invention relates to apparatus for cleaning elongated tubular surgical instruments. More particularly, it relates to apparatus for removing the X-ray dyes used in closed- circuit balloon-equipped catheters, such as bRT catheters and similar instruments.

Background of the invention Percutaneous transluminal coronary angioplasty

(PTCA) - a technique used to widen coronary arteries (the arteries supplying the heart) narrowed by coronary artery disease

- is a well-known medical procedure which has been continually perfected since its inception in 1977. This technique employs a catheter, a thin flexible instrument formed by two concentric tubes, the inner one being open in both ends and the outer one having a small inflatable balloon at its distal end. Said inner tube is often referred to as "open circuit" the outer tube being the "closed circuit". During the procedure the catheter is inserted through an artery in the groin (femoral approach) or the arm (brachial approach) , and maneuvered so that its tip reaches the narrowed portion of the coronary artery, when the balloon is inflated by means of physiological solution injected under pressure. The tortuosity of the vascular system requires some means that will allow the surgeon to visualize the instrument as it is maneuvered within the blood vessels. This visualization is achieved by filling the closed circuit with X- ray dye, enabling the progress of the instrument to be seen by means of X-ray fluoroscopy.

The cost of catheters represents a significant portion of the procedures, PCTA catheters being quite expensive. Although in some developed countries the catheters are simply discarded after use, the reuse of such catheters would significantly allow for a larger number of patients in regions or communities where medical resources are scarce. Said reuse entails the cleaning of the catheters followed of their sterilization. The cleaning procedure comprises the following steps :

- In the open circuit, through which the guide wire passes and which is .in contact with the patient's blood, the cleaning operation is performed by flushing manually immediately following the end of the procedure.

- I-n the closed circuit, it is necessary to remove the X-ray dye from the lumen of the tube and the balloon, because said dye may crystallize on the balloon wall, weakening it with the ensuing danger of rupture under the inflating pressure.

The washing of the closed circuit is usually conducted by nurses or nursing by a manual procedure which entails the injection of liquid and withdrawal by means of a syringe. The effectiveness of this operation is highly dependent on the quality of the human factor, the worker being influenced by external and internal factors which can impair the final quality of this cleaning procedure.

Automated catheter reprocessing systems have been proposed with the purpose of eliminating the influence human factor, such as the one described in the patent US 5,921,256 - Apparatus and method for cleaning elongated hollow instruments. This document describes a highly complex apparatus comprising clamping means allowing the simultaneous processing of several instruments, as well as of pumps for liquid and air injection, control valves and miscellaneous parts, the operation being controlled by a microprocessor. Besides being highly complex and quite expensive, said equipment provides only the cleaning of tubular instruments open at both ends, not being adaptable for washing closed circuit devices.

Another catheter washing system is described in JP 5609759 - Apparatus for washing catheter in water. This device comprises a motor-actuated pump coupled to a valve and a manifold provided with several outlets, each of which receives the proximal end of the catheter to be washed, the distal end being left open. Although being less complex and cheaper than the system described in US 5,921,256 there are several drawbacks associated with this apparatus, such as the fact that it only washes open circuit instruments, i.e., those being open at both ends. Moreover, this system is operated manually, with all the irregularities associated with the human factor.

Objects of the invention

It is therefore the main object of the invention to provide an apparatus and a cleaning method for the catheters' closed circuits that allows their reprocessing in a safe, efficient practical and economical way.

It is another object of the invention to provide a method that insures the uniformity and repeatability of the cleaning process. It is yet another object of the invention to provide a method and apparatus that are independent of the human factor.

It is still another object of the invention to provide a method and apparatus that will turn out catheters with a level of cleanliness that allows their reuse, avoiding at the same time any impairment of their functional qualities.

Brief summary of the invention

The preceding aims are achieved by the invention by providing an automated apparatus and a washing method

^• comprising a plurality of cycles consisting, each one, of the introduction of purified water in the catheter or similar devices by means of positive pressure followed by the extraction of said water containing the X-ray dye by suction produced by negative pressure.

According to another feature of the invention, the apparatus comprises means for introducing water under pressure, negative pressure providing means for water suction, solenoid-actuated valves for water flow control and adjustable timing means which allow the adjustment of the period of each step of the cycle.

According to yet another feature of the invention, the injection period is longer than the suction period. Brief description of the drawings

The above objects and advantages of the present invention will become more apparent by the detailed description of a preferred embodiment thereof with reference to the appended drawings in which: Fig. 1 is a schematic diagram showing the main components of the apparatus of the present invention.

Fig. 2 is a timing diagram of the system operation. Detailed description of the invention

Referring now more particularly to Fig. 1, the proposed apparatus comprises a water inlet 11, a first solenoid- actuated valve 12 which controls the water injection, a second solenoid-actuated valve 17 which controls the water suction, a Tee connection 13, an adapter 14 for attachment of the proximal end of catheter 15, said catheter being provided with an inflatable balloon 16 on its distal end, a suction pump 19 connected to said solenoid-actuated valve 17, said pump discharging into a collecting jar 21, a timer 22 electrically connected to an alternating device 23 and indicating LED' s 24. For clearness of the diagram, the electric mains connections as well as the power switch are not shown in the drawing.

Referring now to Fig. 1 and Fig. 2, the operation of the system comprises a sequence of similar cycles, each one of which comprises the steps of opening the solenoid- actuated valve at time t providing the injection of pressurized water into the catheter, followed by closure of said valve 12 at time t2 and opening of valve 17, simultaneously turning on the suction pump 19, which extracts from the catheter through duct 18 the water carrying the X-ray dye, said water being discharged into the collecting jar 21 to be disposed subsequently. At time t3 pump 19 is turned off and valve 17 is closed, while valve 12 is opened again for injecting water into the catheter, the period of injection being longer than the extraction period, as shown by the timing diagram of Fig. 2. At the end of the injection period, at time t4, valve 12 is once more closed, valve 17 is opened and suction pump 19 is turned on for water extraction, and the same cycle is repeated several times. The negative pressure that provides water suction has a value between 0.3 and 0.5 atmospheres, preferably substantially equal to 0.4 atmospheres.

The overall washing time as well as the duration of the injection and suction steps which constitute each cycle are set in timer 22, depending of the size of the catheter 15, bearing in mind that said timer opens and closes valves 12 and 17 as well as turns on and off the suction pump 19 during the washing operation, switching off all functions at the end of said procedure.

According to the invention, the injection period is substantially longer than the suction period, as shown by Table 1, below.

Table 1

Timing of washing operation of bRT closed circuit catheter

Notwithstanding the fact that the invention was described with reference to a particular embodiment, additional advantages of the present invention will readily occur to those skilled in the art, while keeping within the conceptual bounds of the invention. For instance, an injection pump can be provided in the treated water inlet 11, if its pressure is below the one required for system operation.

It is to be understood, therefore, that it is intended in the appended claims to cover all modifications as fall within the true spirit and scope of the invention.

Claims

We claim :

1. An apparatus for cleaning catheters and other hemodynamic devices characterized by the fact that it comprises a first valve (12) for controlling the water injection, a second valve (17) for controlling the water extraction, a suction pump (19) , coupling means (13, 14) to a closed cycle balloon tipped catheter (15) or a similar hemodynamic device, timing means (22) and an alternating device (23) .

2. A method for cleaning catheters and other hemodynamic devices characterized by the fact that it comprises a plurality of washing cycles, each one of said cycles consisting of a first period (t_x-t₂) during which purified water is introduced by means of positive pressure and a second period (t₂- t₃) during which the washing water is extracted by means of negative pressure.

3. A method, as set forth in claim 2, characterized in that said first period (tι-t₂) is substantially longer than said second period (t₂-t₃) .

4. A method, as set forth in claim 3, characterized by the fact that the proportion between said first and said second periods is comprised between 5 and 10.

5. A method, as set forth in claim 2, characterized by the fact that said negative pressure has a value comprised between 0.3 and 0.5 atmospheres.

6. A method, as set forth in claim 5, characterized by the fact that said negative pressure is approximately equal to 0.4.

7. A method, as set forth in claim 2, characterized by the fact that the quantity of washing cycles is equal to 20.