US 3807391 A
An elongated tubular catheter having a tube for discharging a liquid into a heart. A body of electrically conductive material is connected to the tube. The body has a passage for carrying liquid from a dispenser into the tube. An electrical plate electrode connected to the body with a line shunts electric current from the heart. The plate electrode is a disposable item having a flexible sheet base. An electrically conductive skin, as an aluminum sheet, is attached to one side of the base.
Claims available in
Description (OCR text may contain errors)
United States Patent 1191 Bolduc [111 3,807,391 1451 Apr. 30, 1974 CARDIAC CATHETER AND SHUNT ELECTRODE  Inventor: Lee R. Bolduc, Minneapolis, Minn.
 Assignee: Medical Plastics, Inc., Minneapolis,
 Filed: Mar. 12, 1973  Appl. No.: 340,566
Related US. Application Data  Division of Ser. No. 92,767, Nov. 25, 1970, Pat. No. 3,720,209, which is a continuation-in-part of Ser. NOS. 711,949, March 11, 1968, Pat. No. 3,543,760, and Ser. No. 866,630, Oct. 15, 1969, Pat. NO.
 US. Cl.. l28/2.05 R, 128/348, 317/2 B [5l] Int. Cl A6lb 5/02  Field of Search..... l28/2.05 R, 2.05 D, 2.06 R, l28/2.06 E, 2 R, 303.13, 303.18, 348 R, 349 R, 2 E, 2 M; 317/2 R, 28
[5 6] References Cited UNITED STATES PATENTS 3,473,087 10/1969 Slade 128/348 UX 5/1972 Kahn et al l28/2.05 R X 8/l972 Shinnick et al. l28/348 FOREIGN PATENTS OR APPLICATIONS 1,033,971 6/1966 Great Britain 128/348 Primary Examiner-Dalton L. Truluck Assistant Examiner-Lee S. Cohen 57 ABSTRACT An elongated tubular catheter having a tube for discharging a liquid into a heart. A body of electrically conductive material is connected to the tube. The body has a passage for carrying liquid from a dispenser into the tube. An electrical plate electrode connected to the body with a line shunts electric current from the heart. The plate electrode is a disposable item having a flexible sheet base. An electrically conductive skin, as an aluminum sheet, is attached to one side of the base.
11 Claims, 2 Drawing Figures CROSS REFERENCE TO RELATED APPLICATIONS This application is adivision of U. S. application Ser. No. 92,767 filed Nov. 25, 1970, now U. S. Pat. No. 3,720,209. Application Ser. No. 92,767 is a continuationin.-part of U. S. patent application Ser. No. 711,949 filed Mar. 11, 1968, now U. S. Pat. No. 3,543,760 and U. S. patent application Ser. No. 866,630 filed Oct. 15, 1969, now U. S. Pat. No. 3,642,008.
BACKGROUND OF INVENTION SUMMARY OF THE INVENTION The invention relates to a catheter andelectrical conductor means for carrying electricalcurrent from the catheter. The catheter includes a tubular member and means having a passage and electrically conductive properties. A dispensing means discharges liquid throughthe passage and into the tubular member. The conductor means can be a disposable plate electrode connected to the means of the catheter tocarry electrical current away from the catheter and liquid flowing throughthe catheter.
IN THE DRAWINGS FIG. 1 is a diagrammatic view of a device having a cardiac catheter attached to a plate electrode located under the body of apatient positioned on a table; and
FIG. 2 is a diagrammatic view, partly sectioned, of the cardiac catheter and plate electrode of FIG. 1.
The disposable .plate electrode shown in FIG. 1 is usable with a patient during surgery, catheterization and routine electrocardiography to ground and provide an alternate electrical. circuit to the patient. The plate electrode is used to minimize the induction of ventricular fibrillation or multiple extra systoles when an electrical apparatus is connected to the patient. It is known that alternating current having 60 cycle per second frequency, as used in the United States of America, is among the most prone to cause ventricular fibrillation. The threshold of ventricular fibrillation. with 60 cycle alternating current shocks administered to human hearts is very low, in the neighborhood of 180 microamperes. With a safety factor of 10, it has been found that shocks exceeding 2 microamperes of 60 cycle alternating current are regarded ashazardous if delivered directly to the human heart. Human studies indicate that 60 cycle shocks are 500 to 5000 times more dangerous when delivereddirectly to the heart rather than the body surface. The very small magnitude of the shocks capable of producing ventricular fibrillation may be appreciated in light of the observation that at 60.cycles currents less than one microampere cannot be detected through the skin. Saline of blood filled cardiac catheters andpacemaker electrodes are the usual 1 means of gaining electrical access to the human heart.
To minimize the electrocution hazards, the voltage difference between the talbe and the patient and the apparatus or device which may be attached directly to the heart or any other part of the body must be eliminated or reduced to less than a few microamperes of current. In the present invention, the apparatus is connected to a disposable plate electrode in surface contact with the skin of the patient to shunt or bypass any electrical current that may flow between the apparatus and the patients heart.
Referring to FIG. 1, there is shown a patient 300 located on a table 301. An electrical apparatus, indicated generally at 302, having an electrically conductive saline solution 303 is connecteddirectly to the patients heart 304 and a source of alternating current 305 used to operate the apparatus. The apparatus 302 comprises an intracardiac catheter 306. The catheter 306 is an elongated flexible plastic tube for carrying the saline solution 303 to one of the chambers of the heart 304. A coupling 307 is used to connect the catheter to a dye injector 311. The coupling 307 has an electrically conductive body 308 of metal or the like carrying an electrically insulative coating or skin 309. The dye injector 311 may be replaced with a densimeter or other apparatus for monitoring the condition of the heart. As shown in FIG. 1, a plate electrode indicated generally at 312 is located-on the table 301 in surface engagement with the back of the patient 300. The electrode 312, shown in FIG. 2, has a substantially flat base 313 of electrically insulative material, as cardboard. Secured to one side of the base 313 is an electrically conductive skin 314 of aluminum, tin, or similar conductive metal. The-skinand base may be of the same materials as used in electrodes disclosed in U. S. Pat. No. 3,543,760. An electrical conductor 316, as a line or wire, is connected to a clamp 317. Clamp 317 is in engagement with skin 314. The line 316 is secured to the body 308 of the connector 307 and thereby electrically connects the fluid or saline liquid 303 with the electrode 312.
In use, the electrode 312 shunts or shorts away most of the current from the heart 304. The line 316 and electrode 312 together have less resistance to the current than the saline liquid in the catheter 306. The ratio of resistance between the line 316 and electrode 312 together compared to saline column in the catheter 306 is between 300 and 500 to I. This ratio depends upon the diameter and/or length of the saline column. Accordingly, the amount of current applied to the heart is reduced by this factor. The plate electrode 312 along with the connecting line 316 in electrical contact with the saline liquid 303 will substantially reduce the incidence of ventricular fibrillation of the heart 304.
While there has been shown and described a disposable plate electrode for use with an intracardiac catheter, it is intended that the electrode can be used with other electrical apparatus to ground a patient.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. In combination: a cardiac catheter having a tube adapted to carry a liquid to a patients heart, means to supply liquid to said tube, electrode means having an electrically conductive surface adapted to engage an area of the patients body, and electrical conductor means electrically connecting the surface of the electrode means with the liquid in the catheter whereby substantially all electric currents are shunted around the heart.
2. The structure of claim 1 wherein: the electrical conductor means includes a body having a passage connected to the tube, said body being made of electrically conductive material.
3. The structure of claim 2 including: an electrically insulative skin means covering the outside of the body.
4. The structure of claim 1 wherein: said electrode means is a sheet member having an electrically conductive skin.
5. The structure of claim 1 wherein: said electrode means is a sheet member having a generally flat flexible base and electrically conductive skin secured to one side of the base.
6. The structure of claim 1 including: clamp means connecting the conductor means to the electrode means.
7. A catheter and electrical conductor means for shunting electrical current away from the catheter comprising: a tubular member having a longitudinal passage for carrying fluid, means having a passage connected to the tubular member, said passage of the means being in communication with the passage in the tubular member whereby fluid can flow through the tubular member and body means, said means being made of electrically conductive material, electrode means for carrying electric current, and electrical conductor means connecting the means and the electrode means pense fluid through the passage.