AMNIOTOMY INSTRUMENT

Abstract: A medical instrument for use in amniotomy comprising a sleeve (1), for location on an operator's finger (2), having a cutting hook (3) mounted on its end portion.

Description: Amniotomy instrument This invention relates to a medical instrument for use in amniotomy. During childbirth the current technique used for amniotomy, or rupturing the membranes, involves the use of a sharp instrument or forceps which are held in one hand. These instruments must be carefully applied to the membranes with the tip of the instrument guarded by the index finger on the other hand. Such instruments require a great deal of manual dexterity to be used efficiently and to ensure the correct placement of the tip of the instrument. In addition, the use of instruments can cause significant anxiety to the patient and the need for the use of two hands can cause discomfort to the patient. Also, as this technique requires the operator to use both hands an assistant may be required to help stabilise the presenting part. According to the present invention there is provided a medical instrument for use in amniotomy comprising a locating member for locating the instrument on an operator's .finger and a cutting member affixed to the locating member. Preferably, the locating member is in the form of a sleeve which fits over the operator's finger. The sleeve is preferably closed at the end to form a seal over the end of the operator's finger, and most preferably the sleeve is of a length sufficient to envelop the finger to below the first joint. Preferably, the sleeve is formed from a flexible material such as latex or a plastics material. Preferably also, the cutting member is a hook of plastics material such as polystyrene. The cutting member may be of a different material from the locating member and is preferably more rigid than the locating member. Preferably also, the cutting member is disposed on the locating member so as to be on the ball of an operator's finger in use; this provides for maximum sensitivity. Preferably also, the cutting portion of the cutting member is disposed in a direction towards the palm of the operator's hand in use. Preferably also, the cutting member is affixed to the sleeve by adhesive. The locating member may be in the form of a finger cot or may form a finger of a glove, for example the middle or index finger. Further according to the present invention there is provided a method of amniotomy comprising locating a cutting device on an end portion of an operator's finger, inserting the finger through the cervix of a patient, positioning the cutting device adjacent the membranes of the patient and cutting the membranes with the cutting device. Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view showing a first embodiment of a medical instrument for use in amniotomy in accordance with the present invention; Fig. 2 is a perspective view showing a second embodiment of a medical instrument for use in amniotomy in accordance with the present invention; Fig. 3 is a view showing the medical instrument of Fig. 1 in amniotomy; and Fig. 4 is a view showing a further embodiment of a medical instrument of the present invention in use. Referring to- Fig. 1 of the drawings, a medical instrument for use in amniotomy comprises a latex sleeve 1, open at the end and having a length and internal diameter selected to allow it to fit tightly over the length of an operator's finger 2, and having a polystyrene hook 3 on its end portion. The hook 2 projects from a disc 5 of polystyrene which is bonded to the latex sleeve 1 with "superglue" adhesive. The polystyrene of the disc 5 and hook 3 is substantially rigid while the latex of the sleeve 1 is highly flexible. The open end of the sleeve 1 is provided with an annular ring 4 of slightly thicker material which the operator may roll along his finger 2 when he wishes to apply or remove • the sleeve 1. Now also referring to Fig. 3, when the instrument is to be used the sleeve 1 is placed over the middle or index finger 2 of an operator's gloved left or right hand after a vaginal examination, the sleeve 1 being positioned such that the disc 5 is situated on the ball of the operator's .finger 2 with the hook 3 directed towards the palm of the hand. The finger 2 is then inserted through the cervix 6 and the hook 3 guided to the appropriate area in order to rupture the membranes 7. As only one finger 2 is inserted into the cervix 6 the patient suffers less pain than with previous techniques and the absence of instruments tends to provoke less anxiety in the patient. The positioning of the hook 3 on the sensitive ball of the finger 2 allows the operator to feel exactly where the hook 3 is to be applied while supporting the presenting part with his other hand. Also, as the finger 2 and latex sleeve 1 are flexible lithotomy is not necessary even when the cervix 6 is posterior, thus giving considerable advantage over the use of rigid instruments. Fig. 2 shows a further medical instrument of the invention where the latex sleeve 1 forms the index finger of a moulded glove 10, and in this case the glove 10 can be applied in preference to routine gloves for elective amniotomy. Fig. 4 shows a further embodiment of the present invention in use. This embodiment features a hook 3 which is pointing in the opposite direction to that of the hooks 3 of Figs. 1 and 2, and in this case the membranes 7 are ruptured by movement of the hook 3 away from the operator. Modifications and improvements may be made without departing from the scope of the invention.

Claims: CLAIMS 1. A medical instrument for use in amniotomy comprising a locating member for locating the instrument on an operator's finger and a cutting member for rupturing membranes, the cutting member being affixed to the locating member. 2. A medical instrument as claimed in Claim 1, wherein the locating member is in the form of a sleeve for receiving an operator's finger. 3. A medical instrument as claimed in Claim 2, wherein the sleeve is flexible. 4. A medical instrument as claimed in Claim 3, wherein the cutting member is more rigid than the locating member. 5. A medical instrument as claimed in any one of the preceding Claims, wherein the cutting member is affixed to the locating member in a position whereby in use the cutting member is disposed at the ball of an operator's finger. 6. A medical instrument as claimed in any one of the preceding Claims, wherein the cutting member is in the form of a hook. 7. A medical instrument as claimed in Claim 6, wherein the hook has a sharp point facing in use towards the palm of the operator's hand. 8. A medical instrument as claimed in any one of the preceding Claims, wherein the cutting member is affixed to the locating member by adhesive. 9. A medical instrument as claimed in any one of the preceding Claims, wherein the locating member forms the finger of a glove. 10. A method of amniotomy comprising locating a cutting device on an end portion of an operator's finger, inserting the finger through the cervix of a patient, positioning the cutting device adjacent the membranes of the patient and cutting the membranes with the cutting device.

Inventors: O'NEIL ALEXANDER GEORGE BRIAN, O'NEIL, ALEXANDER, GEORGE, BRIAN
Applicants: ONEIL ALEXANDER G B, ONEIL CHRISTINE, PATTULLO NORMAN, O'NEIL, ALEXANDER, GEORGE, BRIAN, O'NEIL, CHRISTINE, PATTULLO, NORMAN
Application year: 1985
Main classification: A61B19
IPC codes: A61B17, A61B19