Surgery – Diagnostic testing – Measuring fluid pressure in body
Reexamination Certificate
2001-06-29
2003-12-23
Winakur, Eric F. (Department: 3736)
Surgery
Diagnostic testing
Measuring fluid pressure in body
Reexamination Certificate
active
06666828
ABSTRACT:
FIELD OF THE INVENTION
This invention is generally directed to the field of medical catheter systems and balloons therefor.
BACKGROUND OF THE INVENTION
Urethral pressure measurements have been used for more than 75 years to assess urethral closure function. Urethral pressure and urethral closure pressure are idealized concepts which aim to represent the ability of the urethra to prevent leakage. So long as the intraurethral pressure exceeds the proximal fluid pressure, urine cannot leak and therefore the subject should be continent. Measurement of urethral pressures requires the introduction of a catheter adapted to perform such measurements. A variety of different techniques are employed to make urethral pressure measurements. Moreover, in the field of urethral impedance planimetry, it is known to measure the elasticity or “tonus” of the urethra, the cross-sectional area of the urethra, bladder pressure, abdominal pressure and detrusor pressure. EMGs and imaging data may also be obtained when making such measurements.
One well known technique for assessing a patient's bladder function is PCA (or “Pressure Cross-Sectional Area”) catheter measurement as described, for example, in “A System for Measurement of Micturition Urethral Cross-Sectional Areas and Pressures” by Mortensen et al., Med. & Biol. Eng. & Comput., 1983, 21, 482-488; “Simultaneous Recording of Pressure and Cross-Sectional Area in the Female Urethra: A Study of Urethral Closure Function in Healthy and Stress Incontinent Women” by Lose in “Neurology and Urodynamics,” Volume 11, Number 2, 1992; and “Urethral Pressure Measurement—Problems and Clinical Value” by Lose, Scand. J. Urol. Nephrol. Suppl. 207. See also “Urethral Impedance Planimetry” presented by Lose et al. at the Medtronic Satellite Symposium, ICS, Tampere, Finland, 2001.
FIG. 1
shows a prior art PCA catheter system
5
comprising catheter body
10
, expandable and resilient balloon
20
mounted near distal end
30
of the catheter, balloon channel
40
for introducing saline solution
50
inside and removing saline solution
50
from balloon
20
, distal micro-pressure transducer
60
mounted near distal tip
70
of catheter body
10
, proximal micro-pressure transducer
65
mounted beneath a portion of balloon
20
and situated proximally from distal pressure transducer
60
, and electrodes
80
A,
80
B,
80
C and
80
D mounted beneath balloon
20
on catheter body
10
. Electrical connectors
9
at the proximal end of catheter system
5
permit electrical connections to be established between electrodes
80
A through
80
D, transducers
60
and
65
, or temperature or other sensors, and external recording and/or analysis equipment (not shown in the Figures).
Cross-sectional area (or “A”) is determined by delivering high frequency alternating current between excitation electrodes
80
A and
80
D and measuring the electrical conductivity of the saline solution inside balloon
20
. Balloon
20
is then inflated and deflated incrementally with saline solution during rest and provocative maneuvers, and the drop in voltage between sensing electrodes
80
B and
80
D is measured. Using the field gradient principles described by Harris et al. in “Electrical Measurements of Urethral Flow” in “Urodynamics”, New York, Academic Press, Chapter 34, page 465, cross-sectional area A may be determined. The pressure inside balloon
20
may be increased incrementally to induce dilation, and the resulting pressures may be recorded using the proximal and distal pressure transducers. The resulting pressure response curve is a stress relaxation curve, which may be analyzed to determine the elastic properties of the patient's urethra. Balloon
20
is preferably fully distensible within the physiological range of the urethral cross-sectional area.
It will now be seen that PCA catheter system
5
comprises several expensive components, most notably distal micro-pressure transducer
60
, proximal micro-pressure transducer
65
, and electrodes
80
A,
80
B,
80
C and
80
D. In addition, catheter system
5
requires the incorporation of balloon channel
40
and the inclusion and mounting of balloon
20
. Because the cost of a single PCA catheter system
5
may easily exceed several thousand dollars, it is preferable that at least portions of PCA catheter system
5
be reusable following sterilization.
To date, some PCA catheters have been re-used by mounting disposable balloons on catheter body
10
using sutures or ties
75
that are secured around the proximal and distal ends
85
and
90
of balloon
20
. Mounting balloon
20
on catheter body
10
using such manual attachment techniques is time consuming, tedious and does not produce reliable seals between proximal and distal ends
85
and
90
of balloon
29
and the outside diameter of the catheter. What is needed is a PCA catheter system having a disposable balloon which may be readily and quickly mounted on or removed from a catheter body, and which also provides a competent non-leaking seal between the balloon and the catheter when the balloon is filled with saline solution.
Patents and printed publications describing various aspects of the foregoing and other problems, as well as the state of the art, are listed below.
1. U.S. Pat. No. 4,023,562 to Hynecek et al. entitled “Miniature Pressure Transducer for Medical Use and Assembly Method.”
2. U.S. Pat. No. 4,191,196 to Bradley et al. entitled “Profilometry Method and Apparatus” to Ellis.
3. U.S. Pat. No. 4,545,367 to Tucci entitled “Detachable Balloon Catheter and Method of Use.”
4. U.S. Pat. No. 5,385,563 to Gross entitled “Urodynamic Catheter.”
5. U.S. Pat. No. 5,449,345 to Taylor et al. entitled “Detachable and Reusable Digital Control Unit for Monitoring Balloon Catheter Data in a Syringe Inflation System.”
6. U.S. Pat. No. 5,549,554 to Miraki entitled “Catheters Having Separable Reusable Components.”
7. U.S. Pat. No. 5,766,081 to Kreder entitled “Urethral Pressure Catheter.”
8. U.S. Pat. No. 5,779,688 to Imran et al. entitled “Low Profile Balloon-On-A-Wire Catheter with Shapeable And/Or Deflectable Tip and Method.”
9. U.S. Pat. No. 5,876,374 to Alba et al. entitled “Catheter Sleeve for Use with a Balloon Catheter.”
10. U.S. Pat. No. 5,919,163 to Glickman entitled “Catheter with Slideable Balloon.”
11. U.S. Pat. No. 5,941,871 to Adams et al. entitled “Catheter Systems with Interchangeable Parts.”
12. U.S. Pat. No. 6,021,781 to Thompson et al. entitled “Intraurethral Pressure Monitoring Assembly and Method of Treating Incontinence Using Same.”
13. U.S. Pat. No. 6,136,258 to Wang et al. entitled “Method of Forming a Co-Extruded Balloon for Medical Purposes.”
14. U.S. Pat. No. 6,231,524 to Wallace et al. entitled “Pressure Device with Enhanced Fluid Monitoring Features.”
All patents and printed publications listed hereinabove are hereby incorporated by reference herein, each in its respective entirety. As those of ordinary skill in the art will appreciate readily upon reviewing the drawings set forth herein and upon reading the Summary of the Invention, Detailed Description of the Preferred Embodiments and Claims set forth below, at least some of the devices and methods disclosed in the patents and publications listed hereinabove may be modified advantageously in accordance with the teachings of the present invention.
SUMMARY OF THE INVENTION
Various embodiments of the present invention have certain objects. That is, various embodiments of the present invention provide solutions to problems existing in the prior art, including, but not limited to, one or more of the problems listed above.
Various embodiments of the present invention have certain advantages, including, without limitation, one or more of: (a) permitting expensive catheter components or catheters to be re-used; (b) reducing the amount of time required to mount a disposable balloon on a catheter; (c) reducing the cost of medical procedures carried out using the balloon of the present invention; (d) increasing the competence and leakworthiness of seals made using the balloon of the present invent
Aundal Knud
Greco Francesco
Jørgensen Kenneth
Nielsen Marianne
Pedersen Anders
Medtronic Inc.
Szmal Brian
Winakur Eric F.
Woods Thomas F.
LandOfFree
Catheter system having disposable balloon does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Catheter system having disposable balloon, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Catheter system having disposable balloon will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3147482