GB2297036A

GB2297036A - Inflatable cervical dilator

Info

Publication number: GB2297036A
Application number: GB9600184A
Authority: GB
Inventors: Alexander Kostic
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-01-05
Filing date: 1996-01-05
Publication date: 1996-07-24
Anticipated expiration: 2016-01-05
Also published as: GB2297036B; GB9600184D0; GB9500134D0

Abstract

An inflatable cervical dilator comprises a flexible steel guide 4 on which is mounted inner balloon 3 covered by furled silk sleeve 5 which is in turn covered by outer balloon 2 . On inflation of inner balloon 3 , the furled silk sleeve 5 slides out of plastic body 8 to form a tubular shape suitable for cervical dilation. Protective outer balloon 2 follows the same shape and protects against leakage. Furled silk sleeve 5 once expanded cannot be retracted and restricts the device to once only use. A third shortened piece of balloon 10 holds the lower end of the silk sleeve 5 and is also used to pressure test the device during production. Evacuation holes 6 are provided in the plastic body 8 for emergency cessation of dilation.

Description

GYNEACOLOGICAL PNEUMATIC PARACHUTE DILATOR SONDE This invention relates to a sonde used in standard gyneacological procedures to open Human Cervix Uteri (HCU) for inspection and other medical purposes.

This inventions updates invention 95000134.3 from 05/01/1995 and it has better capabilities in respect of safety and serial production.

Various penetration methods have been used in past to overcome the natural resistance of tissues at the opening of HCU, commencing with the plant Laminaria used in ancient Egypt to Hegar instruments, now in general use. When implanted in HCU, Laminaria has the capability of increasing the diameter of HCU for several hours. The procedure was subject to infection, and difficulties occurred when it was extracted, either as whole, or in pieces. Dr.Hegar /1831-19141 designed a method of opening the HCU by introducing a set of cylindrically shaped metal rods of diameters ranging from 4 mm to 12 mm. This was based on successive penetration of HCU by rods of gradually increasing diameter. This system is universally used in medicine today.

Hegar instrument - dilators are operated on the basis of the "Nail principle" by the hand of gyneacologist using axial brute force. Measured axial force can reach 50 N (Newton) in the case of 12 mm dilator. Axial force is only effective in it radial component. The other component pushes and damages the inlet of the HCU with pressure and friction, thus causing pain, possible laceration, and penetration. It also makes the operation risky as a high level of force is required to overcome the natural reaction and sudden release of the HCU.

According to the present invention the sonde applies radial force only. Compressed air inflates an internal balloon which in turn opens a silk parachute, simulating the action of the plant Laminaria in shape of Hegar instrument, which fits exactly the space of HCU endometrium.

A description of invention now follows accompanied by drawings ( pages 112 and 2/2) in which: Figure 1 shows the Pneumatic Parachute Dilator Sonde ( PPDS) in perspective with the following parts: 1. Plastic tip with collar 2. Protective outer balloon with "O" ring 3. Intemal balloon with "0" ring 4. Flexible steel needle guide 5. Silk parachute 6. Three emergency evacuation air holes 7. Air evacuation collar 8. Upper plastic body 9. Hole for securing the needle 10. Third shortened piece of balloon (without upper end) with "0" ring which holds lover end of silk parachute (5) 11. Narrow hole for passing the compressed air into the internal balloon (3) 12. Lower plastic body base with central hole and lower end adjusted to match snap-on compressed air standard connector.

Figure 2 illustrates in detail the upper plastic body (8) with central guide hole, three emergency evacuation holes (6) and evacuation air collar (7).

Figure 3 shows the lower plastic body (12) with the wholes fcr needle (9) and air (11).

With the reference to Figure 1 the specified parts serve the following functions during dilatation process of HCU.

From the bottom of PPDS the compressed air is gradually applied via the plastic lower base (12) through the main hole attached to a snap-on compressed air connector. The air passes through the narrow hole (11) and expands the internal balloon (3) secured by the "0" ring which holds down the balloon and prevents any leakage of air. The expansion of the balloon (3) pushes the parachute (5) until it gradually slides out along the central guide hole of the upper plastic body (8) to form a specific tubular shape. The third short cut piece of balloon (10) follows sliding out of parachute (5) until a certain pressure level at which if the PPDS deflated is capable to retract back the parachute to its initial position. This process serves in production testing against any initial leakage of PPDS.If the air pressure is greater than test level, the parachute (5) and short piece of balloon are disengaged and parachute is not possible to be retracted. The protective outer balloon (2) follows the same shape as inner balloon (3) and parachute (5), serving as hygienic protection and against any leakage of air from inside. If the air passes through three emergency holes (6) the process of dilatation is terminated immediately. After reaching its final tubular shape (maximum diameter 12 mm) further dilatation is halted.

The initial and final PPDS shape achieved are shown in Figures 4 and 5. The shapes are same for those obtained by Hegar dilators of 4 and 12 mm although only radial force has been used.

After dilatation is completed, compressed air is drawn back through the compressed air connector, thus enabling smooth and easy extraction of the PPDS.

The PPDS is designed for single use as parachute (5) once opened with final pressure cannot be retracted. This also satisfies conditions of medical sterility. The PPDS is sterilized and packed in single transparent pouch.

Claims

C L A I M S

1. A gyneacological pneumatic dilator sonde (PPDS) comprising two plastics, three balloons, parachute, needle guide and emergency evacuation holes with collar form the instrument for dilatation of Human Cervix Uteri (HCU).

2. The gyneacological pneumatic parachute dilator sonde (PPDS) as claimed in Claim 1 enables dilatation of (HCU) to be achieved by parachute which applies radial force only.

3. The gyneacological pneumatic parachute dilator sonde as claimed in Claim 1 and Claim 2 forms a tubular shape which is most suitable for required purpose and satisfies medical requirements of endometrium.

4. The gyneacological pneumatic parachute dilator sonde (PPDS) as claimed in Claim 1 and Claim 2 is for single use only because of its non-retractable parachute in the final step of action.

5. The gyneacological pneumatic parachute dilator sonde (PPDS) as claimed in Claim 1, and Claim 3 incorporates a protective device against leakage of compressed air comprising three emergency holes and emergency air evacuation collar.

6. The gyneacological pneumatic parachute dilator sonde (PPDS) has a third short cut balloon which enables initial test of the sonde during production.

7. The gyneacological pneumatic parachute dilator sonde(PPDS) is described herein with reference to figures 1-5 of the accompanying drawings (pages 112 and 2/2).