U.S. patent application number 11/391150 was filed with the patent office on 2006-09-07 for mr-compatible fluid valve.
This patent application is currently assigned to Siemens Aktiengesellschaft. Invention is credited to Rainer Kuth, Thomas Rupprecht.
Application Number | 20060200065 11/391150 |
Document ID | / |
Family ID | 7682130 |
Filed Date | 2006-09-07 |
United States Patent
Application |
20060200065 |
Kind Code |
A1 |
Kuth; Rainer ; et
al. |
September 7, 2006 |
MR-compatible fluid valve
Abstract
An implantable fluid valve for the adjustable limitation of the
fluid pressure in the brain of a patient has all valve component
parts composed of non-magnetic material, thereby making the valve
MR-compatible.
Inventors: |
Kuth; Rainer;
(Herzogenaurach, DE) ; Rupprecht; Thomas;
(Uttenreuth, DE) |
Correspondence
Address: |
SCHIFF HARDIN, LLP;PATENT DEPARTMENT
6600 SEARS TOWER
CHICAGO
IL
60606-6473
US
|
Assignee: |
Siemens Aktiengesellschaft
|
Family ID: |
7682130 |
Appl. No.: |
11/391150 |
Filed: |
March 27, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10126045 |
Apr 19, 2002 |
7066901 |
|
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11391150 |
Mar 27, 2006 |
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Current U.S.
Class: |
604/9 ;
623/23.68 |
Current CPC
Class: |
A61M 27/006
20130101 |
Class at
Publication: |
604/009 ;
623/023.68 |
International
Class: |
A61F 2/04 20060101
A61F002/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 20, 2001 |
DE |
10119452.8 |
Claims
1. An implantable fluid valve comprising: a plurality of valve
parts including an inlet adapted to receive cerebrospinal fluid and
an outlet adapted to discharge cerebrospinal fluid and adjustable
components disposed in a pathway between said inlet and said outlet
for adjusting fluid flow through said pathway; said plurality of
valve parts comprising a pushbutton mechanism, separate from said
adjustable components, having pushbuttons which interact with said
adjustable components to adjust said adjustable components, said
pushbuttons being adapted for subcutaneous actuation by externally
applied pressure; and all of said plurality of valve parts being
composed of an MR-compatible material.
2. A fluid valve as claimed in claim 1 wherein said adjustable
components include first and second relatively adjustable
components, and further comprising reference markers disposed on
said relatively adjustable components which are visible using a
diagnostic imaging system.
3. A fluid valve as claimed in claim 2 wherein said reference
markers comprise hollow members filled with an MR-visible
fluid.
4. A fluid valve as claimed in claim 1 wherein said MR- compatible
non-magnetic metallic material is selected from the group
consisting of aluminum, brass, titanium CrNiMo steel, and
combinations of aluminum, brass, titanium and CrNiMo steel.
5. A fluid valve as claimed in claim 1 wherein said unlocking
element is an unlocking pushbutton.
Description
BACKGROUND OF THE INVENTION
RELATED APPLICATION
[0001] The present application is a division of U.S. application
Ser. No. 10/126,045, filed Apr. 9, 2002.
FIELD OF THE INVENTION
[0002] The present invention is directed to an implantable fluid
valve for the adjustable limitation of the fluid pressure in the
brain of a patient.
DESCRIPTION OF THE PRIOR ART
[0003] Valves that allow a setting of the maximum pressure from the
outside of a patient, and automatically allow fluid to flow off
given excess pressure, are required for patients whose discharge of
fluid from the brain is abnormal.
[0004] Valves that can be set from the outside by means of magnetic
forces are commercially available. These valves are not
MR-compatible. (As used herein, MR stands for magnetic resonance.)
Examination of the patient in conventional MR scanners thus is not
possible without risk, particularly given flux densities of 1 T and
above. A maladjustment of the programmed pressure level or even
damage to the implanted valves is a frequent complication even
given the use of low-field MR scanners.
[0005] Although having parts composed of rubber, a setting of the
fluid pressure is not possible at all with a fluid valve disclosed
by U.S. Pat. No. 3,595,240, which derives from a time when magnetic
resonance systems were not yet known, so that the problem of an
MR-compatible fluid valve did not arise at all.
[0006] In one embodiment of a cerebrospinal fluid shunt valve
disclosed in U.S. Pat. No. 4,551,128, adjustment is possible by
only puncturing the scalp to allow access of a screwdriver or the
like to an adjustment screw. This is unacceptable in practice
particularly because of the risk of infection and moreover this
fluid valve has metallic parts that are fundamentally incompatible
with MR. In another embodiment of this known valve, magnetic
adjustment for the adjustable limitation of the fluid pressure is
even worse as to MR compatibility. That embodiment includes
magnetic component parts that could create life-threatening
complications in conjunction with the extremely high field
strengths of the basic magnetic field of an MR system. Thus, this
known fluid valve is neither suitable for utilization with MR
monitoring observation nor was this even envisioned.
[0007] The same is also true of a fluid valve according to U.S.
Pat. No. 5,167,615 that likewise contains magnets for setting the
respective pressure.
[0008] British patent application GB 2 143 008 as well as European
patent application 0 233 325 also disclose valves that are not
MR-compatible. The use of stainless steel is expressly prescribed
in the former which makes this valve non-MR-compatible because MR
compatibility not only involves avoiding magnetic components but
also avoiding components having good electrical conductivity since
considerable artifacts could otherwise arise.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide an
adjustable MR-compatible fluid valve.
[0010] This object is inventively in an adjustable valve wherein
all valve parts are composed of MR-compatible non-magnetic
material. A push-button mechanism with key stems that are
subcutaneously actuatable through the scalp can be provided for
setting the valve parts that can be rotated relative to one
another.
[0011] As a result of the inventive fabrication of all valve
components of non-magnetic material, for example aluminum, brass,
titanium, V4A, steel (CrNiMo steel) plastic or combinations of
these materials, a fluid valve is achieved that enables MR
examinations of the patient after the implantation. It has been
shown that it is precisely those patients who have a discharge
disorder who require MR examinations of the head with above-average
frequency. The need for MR-compatibility of the fluid valve is thus
intensified. The pushbutton mechanism for the rotary adjustment of
the valve parts relative to one another can be constructed similar
to the rotary mechanism of ballpoint pens, automatic pencils or the
like wherein a rotary motion is triggered when a button is pressed.
Two pushbuttons are preferably provided for the inventive
adjustment of the setting parts of a fluid valve, one opening the
valve step-by-step and the other pushbutton producing a
step-by-step closing of the valve.
[0012] In a further embodiment of the invention, an interlock
mechanism having an unlocking element can be provided that must be
actuated simultaneously with the setting elements. An adjustment of
the fluid valve by actuating the pushbutton mechanism can occur
only when the unlocking element, i.e., for example, a further
enable button, also is pressed. This prevents an inadvertent
adjustment of the pressure setting of this fluid valve when the
region of the head of the patient where the fluid valve is
implanted under the scalp is inadvertently struck or touched, which
could possibly lead to serious health risks.
[0013] Markings that are visible using imaging diagnostic systems
can be provided at the valve parts that are adjustable relative to
one another, for example oblong hollow members filled with an
MR-visible fluid. Reference markers are also possible that can be
seen in X-ray images, ultrasound images or the like.
DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic section through the implantation
location of an inventive fluid valve in the head of a patient.
[0015] FIG. 2 is a plan view of the fluid valve in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The illustrated fluid valve 1 is secured to the skull bone 2
under the scalp 3, so that the adjustment pushbuttons 4 and 5 as
well as an unlocking pushbutton 6 can be actuated through the scalp
3. The unlocking pushbutton 6 serves for enabling the adjustment
pushbuttons 4 and 5. The adjustment pushbuttons 4 and 5 can cause
an adjustment of the valve body parts 7 and 8 that are rotatable
relative to one another only when the unlocking pushbutton 6 also
is pressed. The pushbuttons 4 and 5 respectively serve for opening
and for closing the valve. The inner valve part 8 turns one step in
the one or other direction relative to the outer part 7 each time a
pushbutton 4 or 5 is pressed. Hose connection conduits 9 and 10
allow the inventive fluid valve to be inserted into the fluid
system of the patient, so that a discharge of the fluid supplied to
the fluid valve 1 at 9 ensues via the drain hose conduit 10.
[0017] In order to be able to recognize the setting of the fluid
valve from the outside, reference markers 11 and 12 are attached to
the valve parts 7 and 8 that are rotatable relative to one another.
These reference markers can be visual with an imaging diagnostic
system, for example an X-ray, ultrasound, or MR system or the like.
For recognition in magnetic resonance examinations, these reference
markers 11 and 12 can be oblong hollow members filled with an
MR-visible fluid. For identifying the valve position, a slice is
therefore to be examined such that both hollow members lie
precisely in this slice plane. This is checked in the image by the
length of the image of the hollow member in the slice image being
measured. If the measured value is too small, then the measurement
layer has been incorrectly placed. The adjustment of the valve, and
thus the opening pressure, are linearly calculated from the angle
of the hollow bodies relative to one another.
[0018] Although modifications and changes may be suggested by those
skilled in the art, it is in the intention of the inventors to
embody within the patent warranted hereon all changes and
modifications as reasonably and properly come within the scope of
their contribution to the art.
* * * * *