Surgery – Diagnostic testing – Measuring electrical impedance or conductance of body portion
Reexamination Certificate
2000-01-12
2001-11-06
Winakur, Eric F. (Department: 3736)
Surgery
Diagnostic testing
Measuring electrical impedance or conductance of body portion
C600S554000, C128S898000
Reexamination Certificate
active
06314315
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of this invention is use of a characteristic electrical signal to identify the location of milk duct orifices on mammalian breast nipples for purposes including accessing one or more of the milk ducts.
Analysis of ductal secretions from human breasts has been used to diagnose biological conditions of the breast ducts (
1
-
4
; see list of references hereinafter). The human nipple has from 6 to 12 ducts, and most of these studies pooled secretions or nipple aspirate fluid (NAF) for the analysis. Thus, the secretions of an individual duct are not identified in these studies. More recently, breast duct access has been incorporated into ductal fluid analyses and study protocols (
5
-
7
). Various methods have been employed in order to identify the breast ducts for purposes including duct fluid analysis (
8
-
15
). Additionally, breast ducts have been accessed by ductscope (
15
,
16
). Ductal cannulation is proposed for delivery of agents (WO 97/05898 and (
20
)). Ductography, or mammary duct contrast examination, involves cannulation and injection of a ductal orifice (
17
-
19
), a process that is generally painless and devoid of complications (
20
).
Ductal access is also required for performing lavage procedures on a milk duct to deliver an agent and/or to retrieve cells from the duct for analysis as described in co-pending and co-owned or licensed applications including Ser. No. 09/067,661; 09/301,058; PCT US99/09141; 60/122,076; 09/313,463; 60/143,359; and application Ser. Nos. 09/473,510, filed Dec. 28, 1999, all incorporated by reference in their entirety. The challenge for the procedure can be finding a duct, or multiple ducts, for access.
It would therefore be desirable to provide improved methods, devices, and kits for accessing breast ducts. More particularly, it would be desirable to provide for the improved detection and identification of individual ductal orifices to facilitate subsequent ductal access for diagnostic and/or therapeutic purposes. Such methods, devices, and kits should be convenient and relatively simple to use, should present the patient with minimal or no discomfort, and should be highly reliable, i.e., should be able to detect all individual ductal orifices in a nipple in all or most cases. At least some of these objectives will be met by the invention described hereinafter.
2. Relevant Literature
WO 96/12439 assigned to TransScan Research & Development Corporation describes electrical impedance imaging devices having multi-element probes for providing electrical connection to tissue surfaces, particularly for detection of cancer in a live tissue, including breast tissue. U.S. Pat. No. 5,810,742 assigned also to TransScan describes an apparatus for making a tissue characterization in order to identify anomalous tissue. Faupel and Hsu, (1996)
Electropotentials in the clinical assessment of breast neoplasia
, Dixon eds. pp.37-44 describe measuring and analysis of skin potentials for cancer diagnosis. U.S. Pat. No. 5,678,547 to Biofield Corp. describes use of an electromagnetic field present between a reference and plurality of test points on a living organism to measure a gradient of electrical activity that occurs as a function of biological activity in order to monitor efficacy of a treatment for the disease, injury or bodily function. U.S. Pat. No. 4,291,708 and U.S. Pat. No. 4,458,694 to Yeda Research & Development Co. describe apparatus and methods for detecting tumors in living human breast tissue including instrumentalities for determining the dielectric constants of a plurality of localized regions of living human breast tissue.
SUMMARY OF THE INVENTION
The present invention provides methods, apparatus, and kits for identifying individual ductal orifices on a nipple surface of a mammalian breast, typically a human female breast. The methods comprise engaging at least one reference electrode against a body surface of the mammal (on the breast or elsewhere) and at least one test electrode against a test location on a surface of the nipple. An electrical current and/or potential is applied between the reference electrode and the test electrode, and a characteristic electric signal produced in response to the applied electrical current and/or potential is measured. The measured value is compared to a base or reference value in order to determine whether the test location is at or near a ductal orifice. Usually, the base electrical value will be a predetermined value, e.g., an average or typical value expected for nipple surface locations which do not comprise the ductal orifice. Alternatively, the base electrical value could be determined for each individual patient, e.g., as an average value determined over a large number of locations on the individual nipple surface where particular measured values at particular locations which differ from the average value determined for that patient will then be likely locations for ductal orifices. The reference electrode will usually be located on the body of the mammal at a location remote from the nipple surface, for example, at the base of the nipple, at the base of the breast, or elsewhere on an abdominal or chest surface of the mammal. Alternatively, in some instances, it will be possible (although generally not preferred) to measure the electrical characteristics between adjacent, laterally spaced-apart locations on the nipple surface in a bipolar manner. Such an approach will determine the surface electrical characteristics of the nipple. Generally, however, it will be preferred to measure electrical characteristic determined from the nipple surface through the “body” of the nipple to an external surface location remote from the nipple.
The test electrode(s) can be applied to the nipple surface in a variety of ways and in a variety of configurations. Most simply, the test electrode can comprise a single electrode element which may be contacted sequentially at multiple points on the nipple surface, either manually or using an automated positioning system. Electrical characteristic values can then be collected or displayed in a variety of ways. Most simply, electrical impedance or other values can be displayed to the person running the test. The person can then observe the value and note changes in electrical characteristics which denote the likelihood of the presence of a ductal orifice. Such manual or semi-automated approaches will be particularly valuable in conjunction with visual confirmation of the presence of an orifice. For example, detection of a change in the electrical characteristics may alert the person running the test to visually scan that area of the nipple more carefully for the presence of the orifice. Alternatively, the individual may simply collect data which is then transmitted to a data collection and analysis system, typically a digital analyzer such as a personal computer.
Alternatively, the test electrode may comprise an array of individual electrodes or electrode nodes which may be simultaneously engaged against a nipple surface or the entire nipple surface in order to generate multiple values of electrical characteristics without the need to reposition the electrode structure being used. In a first instance, the electrode structure could be an electrode array in the form of a patch, membrane, or other flexible support structure which can be applied against the breast, typically using an electrically conductive gel. The array can have a very large number of electrode points or nodes permitting the generation of a map of electrical values over the entire nipple surface. Usually, the map will be generated by sequentially interrogating each of the electrode nodes or elements in order to determine the characteristic electrical value at the position of that node. The data can be collected over a very short time and the map generated using appropriate data collection and digital analysis equipment. The map can then be presented visually, e.g., on a viewing screen, or numerically. Alternatively, the electrode array coul
Grosser Morton
Hung David
Stern Roger A
Banner & Witcoff , Ltd.
Marmor II Charles
Pro Duct Health, Inc.
Winakur Eric F.
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