Surgery – Instruments
Reexamination Certificate
1997-11-06
2001-02-27
Dawson, Glenn K. (Department: 3761)
Surgery
Instruments
C606S130000
Reexamination Certificate
active
06193707
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a method, a device and a system for positioning a probe on a target surface in an open cavity in a test object. The open cavity may, for instance, be a body cavity of a human being or an animal, especially the nasal cavity.
BACKGROUND OF THE INVENTION
Occupying an exposed and fairly immovable position directly on the bone, the nasal mucous membrane is a suitable object of study. When studying the nasal mucous membrane, one occasionally wishes to insert a probe to a carefully determined position in the nose, for instance in order to introduce a chemical substance whose effect on the mucous membrane is to be studied, or in order to carry out a measurement directly on the mucous membrane, for instance measure the circulation in the mucous membrane with the aid of a Doppler laser. In this measurement, the probe has to be placed in a highly exact position in relation to the mucous membrane. The probe must not, for example, press against the mucous membrane, since the pressure might then trigger defence mechanisms altering the circulation. As a result, positioning accuracy in the order of a tenth of a millimeter or so is required. Owing to tremblings of the hand, hair blocking the view and the darkness in the nasal cavity, it is, of course, extremely difficult to manually position a probe so exactly on the nasal mucous membrane. Consequently, previous measurements have not yielded as reliable results as would be desired.
SUMMARY OF THE INVENTION
One object of the invention is, therefore, to provide a method, a device and a system enabling highly exact positioning of an end of a probe on a given location in the nasal cavity.
According to the invention, this object is achieved by a method, a device and a system having the characteristics recited in appended claims
1
,
6
and
12
, respectively. Preferred embodiments are defined in the sub-claims.
To be more specific, it has been found that one may perform highly exact positioning, which in addition can be repeated with a high degree of repeatability, by using a combination of optical technique for defining the place on the mucous membrane where one wishes to position the probe and a device of special design for bringing the probe to this place.
A suitable prior-art optical technique that may be used for implementing the invention is rhinostereometry, which is described in a doctoral thesis written by Jan-Erik Juto and entitled “Rhinostereometry”, the Department of Otorhinolaryngology, Södersjukhuset, Stockholm, 1985, Sweden. A rhinostereometer consists of a microscope which is mounted on a micrometer table. The lens and the eyepiece of the microscope are so chosen as to result in a very shallow depth of field. Today, the rhinostereometer is used for measuring the swelling of the nasal mucous membrane, in which case a small piece of the mucous membrane is observed through the microscope and the swelling is measured with the aid of a scale in the eyepiece.
Thus, the rhinostereometer is located outside the cavity to be examined, which is an advantage, it being as problematic to position an optical instrument introduced into the nose as to position a probe. In addition, there is not much place for the insertion of an optical instrument, the discomfort experienced by the patient is accentuated, and there is a risk of hitting the mucous membrane so that this is interfered with, resulting in less exact later measurements.
However, one problem associated with the use of the above optical technique for introducing a probe into the nose is that the space between the lens of the microscope and the nose is restricted, it being necessary to place the lens close to the nose in order to obtain satisfactory light conditions. On the other hand, a probe that is to be inserted in the nose must have an essentially rectilinear and rigid end portion having a length of about 4-5 cm in order that it should be possible to place its end sufficiently far into the nasal cavity without the remainder of the probe touching the nasal mucous membrane. As a result, there is in most cases not enough room for the end portion of the probe between the rhinostereometer and the nose.
This problem is solved by attaching the end of the probe on a positioning means, which is supported by a stand advantageously consisting of the rhinostereometer, and introducing, in a two-step operation, the end of the probe into the nose. In a first step, the end of the probe is brought to a position on or close to the optical axis of the rhinostereometer a certain distance into the nose by pivoting the positioning means about a pivot point located at a distance from the optical axis and, in a second step, the end of the probe is moved along the optical axis until it has come to occupy the position defined with the aid of the rhinostereometer, more specifically its plane of accurate focus, by moving the positioning means in parallel with the optical axis. Owing to the fact that the positioning means is supported by a stand, the problems associated with manual positioning of the probe, e.g. tremblings of the hand with ensuing inaccuracies, are avoided.
In order that the end of the probe should be able to enter the nose, the probe is suitably turned on the holder in the plane of the pivotal movement, while the positioning means is pivoted.
To many people, the introduction of an object into a body cavity is associated with feelings of discomfort. To enable the probe to be brought directly to the aimed-at position on or close to the nasal mucous membrane, thus minimising the time required for the introduction, a preliminary adjustment without the cooperation of the patient is advantageously performed. Owing to this preliminary adjustment, the end of the probe may then be directly brought to the right position.
It will be appreciated that the above technique for positioning a probe on the nasal mucous membrane may also be used for positioning a probe in other body cavities of a human being or an animal, for instance in the ear or the brain in connection with an operation. This technique may also serve to position a probe in other open cavities of an optional object. For instance, the probe might be a tube intended for the introduction of a substance into the cavity, an instrument for taking a sample of something in the cavity, or an optical instrument, such as an endoscope, for enlarging some part of the cavity.
One may furthermore consider using other optical techniques than rhinostereometry. What matters is that one is able to look into the open cavity in order to select a target surface and that the position of this surface in relation to a reference point, for instance the optical instrument used, can be defined with the aid of the technique employed. Moreover, the optical instrument should, as mentioned in the foregoing, be located outside the cavity.
REFERENCES:
patent: 5184601 (1993-02-01), Putman
patent: 5228429 (1993-07-01), Hatano
patent: 5591175 (1997-01-01), Juto
patent: 5666957 (1997-09-01), Juto
patent: 5695501 (1997-12-01), Carol et al.
patent: 1907235 (1970-08-01), None
patent: 4116810 A1 (1992-11-01), None
patent: 0412282 A1 (1991-02-01), None
“Rhinostereometry”, Jan-Erik Juto, Department of otorhinolaryngology, Södersjukhuset, Stockholm, 1985.
Burns Doane , Swecker, Mathis LLP
Dawson Glenn K.
LandOfFree
Method, device and system for positioning a probe on a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method, device and system for positioning a probe on a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method, device and system for positioning a probe on a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2584390