WO2002007590A2

WO2002007590A2 - Probe tip

Info

Publication number: WO2002007590A2
Application number: PCT/US2001/023192
Authority: WO
Inventors: Rabindra Menezes
Original assignee: Alcon Universal Ltd.
Priority date: 2000-07-25
Filing date: 2001-07-23
Publication date: 2002-01-31
Also published as: CA2412577A1; AU2001277972A1; JP2004504091A; BR0112687A; EP1303217A2; IL153850A0; WO2002007590A3; MXPA03000022A

Abstract

A soft, partially solidified, water-based ultrasound conductive cap sided and shaped to fit over the operative end of an ultrasound probe. The thickness of the cap may be varied to change the focal point during B-Scan biometry.

Description

PROBE TIP

This invention relates to ultrasonic devices and more particularly to ultrasound diagnostic probes tips used in ophthalmology.

Background of the Invention

Many devices use ultrasound energy to construct images of internal organs to help diagnose and treat diseases and other medical conditions. In ophthalmology, for example, both A-Scan and B-Scan ultrasound diagnostic devices are used.

As best seen in FIG. 5, A-Scan biometry uses a relatively small probe and measures the distances between, and thicknesses of, various structures within the eye, such as lens thickness (L), anterior chamber depth (AC), posterior chamber depth (V) and overall axial length (AL). These measurements are useful in determining the required power of the artificial intraocular lens which is implanted during cataract surgery.

As best seen in FIG. 6, B-Scan ultrasound uses a larger probe having an internal motor that wobbles the ultrasound crystal contained within the handpiece. B-Scan ultrasound creates a real time image of the eye and is used to detect the presence of retinal or choroidal detachments, artifacts in the vitreous, tumors or foreign bodies in the eye or to view the posterior segment of the eye when visualization is obscured. B- Scan ultrasound will also make the same measurements made by A-Scan ultrasound.

Measurements using either A-Scan or B-Scan probes are usually performed using the contact method, during which the operative end of the probe is placed in contact with the cornea of the eye under anesthesia. A special ultrasound fluid or gel is used to couple acoustically the probe with the lid or cornea of the eye. This acoustic coupling fluid can make it difficult to align the probe properly, and the gel may irritate the eye tissue. To prevent the spread of pathogens, the probe needs to be cleaned between uses, a difficult and time-consuming step. Even when the probe is cleaned adequately to minimize the spread of any pathogens, the fluid used to clean the probe can irritate eye tissue. In addition, the contact method may not provide precise measurements due to corneal depression resulting from probe contact. The contact method is preferred by most operators, however, because it is easy to perform compared to the immersion method. A second technique used to make A-Scan or B-Scan measurements is the immersion technique. With the immersion technique, the eye is anesthetized and small cup is placed on the eye. The cup is then filled with an acoustic coupling fluid and the probe is inserted into the cup. The immersion technique is considered to be 5 more accurate that the contact method because the probe does not contact and partially depress the eye. The immersion technique, however, is difficult to perform and time consuming and requires that the patient be laying down. In addition, bubbles in the coupling fluid can cause inaccuracies in the measurements.

Accordingly, a need continues to exist for a simple, safe, accurate and reliable o ultrasound coupling device.

Brief Summary of the Invention

The present invention improves upon prior art methods by providing a soft, s partially solidified, water-based ultrasound conductive cap sided and shaped to fit over the operative end of an ultrasound probe. The thickness of the cap may be varied to change the focal point during B-Scan biometry.

It is accordingly an objective of the present invention to provide an ultrasound conductive cap for ultrasound probes. o It is a further objective of the present invention to provide an ultrasound conductive cap that reduces or eliminates the need for an acoustic gel.

Still another objective of the present invention is to provide an ultrasound conductive cap that allows for more accurate ultrasound measurements.

Yet another objective of the present invention is to provide an ultrasound 5 conductive cap that helps prevent the spread of pathogens.

Yet another objective of the present invention is to allow for a biometry procedure that is simple and faster than the contact method and with the precision of the immersion method.

Other objectives, features and advantages of the present invention will become o apparent with reference to the drawings, and the following description of the drawings and claims. Brief Description of the Drawings

FIG. 1 is a top plan view of the probe cap of the present invention useful with an A-Scan ultrasound probe. FIG. 2 is a cross-section view of the probe cap of the present invention taken along line 2-2 in FIG. 1.

FIG. 3 is a top plan view of the probe cap of the present invention useful with an B-Scan ultrasound probe.

FIG. 4 is a cross-section view of the probe cap of the present invention taken along line 4-4 in FIG. 3.

FIG. 5 a schematic representation of the cap illustrated in FIGS. 1 and 2 being used to take a measurement of an eye.

FIG. 6 a schematic representation of the cap illustrated in FIGS. 3 and 4 being used to take a measurement of an eye. ^'

Detailed Description of the Invention

As best seen in FIGS. 2 and 4, probe tip 10 and 10' of the present invention are generally cup-shaped in cross-section, with wall 12 and 12' and end cap 14 and 14', end caps 14 or 14' closing off one end of wall 12 or 12', respectively. Tip 10 illustrated in FIGS. 1 , 2 and 5 is suitable for use with an A-Scan probe and tip 10' illustrated in FIGS. 2, 3 and 6 is suitable for use with a B-Scan probe. Tips 10 and 10' are preferably made of a water-based gel such as a cross-linked cellulose derivative, but any suitable material may be used. Suitable gels are commercially available for sources such as Pharmaceutical Innovations, Inc., Newark, New Jersey.

As best see in FIGS. 1 , 2 and 5 tip 10 suitable for use on an A-Scan probe may be of any suitable inner and outer diameter, but will generally have an inner radius R, of between 0.15 inches and 0.70 inches, with approximately 0.25 inches being preferred, and an outer radius R₀ of between 0.25 inches and 0.85 inches, with approximately 0.45 inches being preferred. Wall 12 may be of any suitable height W_h necessary to hold tip 10 on probe 16, but will generally be between 0.10 inches and 0.80 inches high, with approximately 0.40 inches being preferred. To assist in the installation of tip 10 on probe 16, vent hole 18 may be provided having a diameter D of between 0.01 inches and 0.10 inches, with 0.05 inches being preferred. End cap 14 may have any suitable thickness EC_t, but preferably is between 0.10 and 0.40 inches thick, with approximately 0.12 inches being preferred. End cap 14 also preferably is formed with a curved shape to fit probe 16 and eye 20 securely with minimal rocking and good acoustic contact, with an inner radius R₂ of between 0.75 inches and 1 .25 inches with approximately 0.90 inches being preferred and an outer radius R₃ of between 0.60 inches and 1.40 inches, with approximately 1 .00 inches being preferred. Wall 12 and end cap 14 are preferably joined by internal radius R₄ which is preferably between 0.01 inches and 0.05 inches, with 0.03 inches being preferred and external radius R₅ which is preferably between 0.05 inches and 0.1 5 inches, with 0.10 inches being preferred.

As best see in FIGS. 3, 4 and 6 tip 10' suitable for use on an B-Scan probe may be of any suitable inner and outer diameter, but will generally have an inner radius R of between 0.50 inches and 1 .50 inches, with approximately 0.70 inches being s preferred, and an outer radius R₀' of between 0.85 inches and 1 .70 inches, with approximately 0.90 inches being preferred. Wall 12' may be of any suitable height W_h' necessary to hold tip 10' on probe 22, but will generally be between 0.20 inches and 0.80 inches high, with approximately 0.25 inches being preferred. To assist in the installation of tip 10' on probe 22, vent hole 18' may be provided having a diameter D' 0 of between 0.01 inches and 0.10 inches, with 0.05 inches being preferred, located a distance W₁ from end cap 14' of between 0.01 inches and 0.10 inches, with 0.05 inches being preferred, from end cap 14'. End cap 14' may have any suitable thickness EC_t, but preferably is between 0.10 and 0.40 inches thick, with approximately 0.12 inches being preferred. End cap 14 also preferably is formed with flat internal face 1 5 and 5 curved outer face 1 7 with and an outer radius R₃' of between 0.60 inches and 1.40 inches, with approximately 1 .00 inches being preferred. Wall 12' and end cap 14' are preferably joined by internal radius R₄' which is preferably between 0.03 inches and 0.07 inches, with 0.05 inches being preferred and external radius R₅' which is preferably between 0.10 inches and 0.30 inches, with 0.20 inches being preferred. o One skilled in the art will recognize that the dimensions discussed above may be increased or decreased as required for the probe selected.

In use, as best seen in FIGS. 5 and 6, tip 10 or 10' may be place on the end of A- Scan probe 16 or B-Scan probe 22, respectively and used to make ultrasound measurements of eye 20 or 20'. Tips 10 and 10' may be shipped individually, or may be shipped in a multiple egg carton-like container (not shown).

While the probe tips of the present invention has been described with reference to ophthalmic ultrasound probes, the present invention may also be useful when used in combination with phased array cardiology probes, linear array, curved array and annual array radiology probes

While certain embodiments of the present invention have been described above, these descriptions are given for purposes of illustration and explanation. Variations, changes, modifications and departures from the systems and methods disclosed above may be adopted without departure from the scope or spirit of the present invention.

Claims

I claim: 1 . A probe tip, comprising: a) a circumferential wall; and b) an end cap closing off an end of the wall,

wherein the wall and the end cap are sized and shaped to fit on an end of a probe and the tip is made from a water-based, ultrasonically conductive material.

2. The probe tip of claim 1 wherein the water-based ultrasonically conductive material is a cross-linked cellulose derivative.

3. The probe tip of claim 1 wherein the end cap is sized and shaped to fit on the end of the probe with minimal rocking and good acoustic contact.

4. The probe tip of claim 1 wherein the wall contains a vent hole.

5. The probe tip of claim 2 wherein the gel is a cross-linked cellulose derivative.