U.S. patent number RE37,704 [Application Number 09/534,842] was granted by the patent office on 2002-05-14 for thermal treatment apparatus.
This patent grant is currently assigned to ArgoMed Ltd.. Invention is credited to Uzi Eshel.
United States Patent |
RE37,704 |
Eshel |
May 14, 2002 |
Thermal treatment apparatus
Abstract
Thermal treatment apparatus for thermally treating selected
tissues of a subject located in or near a body cavity, includes a
catheter insertable into the subject's body cavity and having a
proximal end formed with an inflatable anchoring section for
anchoring the catheter in the body cavity, a distal end to be
located externally of the body cavity, and an inflatable heating
section adjacent the proximal end to be located near the tissue to
be heated. The catheter is formed with passageways extending from
the distal end to the inflatable heating section for circulating
heated fluid through the inflatable heating section but not through
the inflatable anchoring section, and a further passageway from the
distal end to the inflatable anchoring section for inflating the
inflatable anchoring section with a non-heated fluid. The
inflatable heating section and the tissue in its proximity may thus
be heated to a desired high temperature without correspondingly
heating the inflatable anchoring section and the tissue in its
proximity.
Inventors: |
Eshel; Uzi (Herzlia Pituach,
IL) |
Assignee: |
ArgoMed Ltd. (Herzlia,
IL)
|
Family
ID: |
22789969 |
Appl.
No.: |
09/534,842 |
Filed: |
March 28, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
212197 |
Mar 11, 1994 |
05549559 |
Aug 27, 1996 |
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Foreign Application Priority Data
Current U.S.
Class: |
604/113; 604/153;
604/97.01; 606/28 |
Current CPC
Class: |
A61B
18/08 (20130101); F24H 1/121 (20130101); A61F
7/12 (20130101); A61F 7/123 (20130101); A61M
25/10 (20130101); F04B 43/1253 (20130101); A61B
2017/22038 (20130101); A61B 2018/00101 (20130101); A61B
2018/00166 (20130101); A61B 2018/00547 (20130101); A61F
2007/0054 (20130101); A61F 2007/0086 (20130101); A61F
2007/0095 (20130101); A61F 2007/025 (20130101); A61M
2205/366 (20130101); A61B 2017/00274 (20130101) |
Current International
Class: |
A61M
25/10 (20060101); A61F 7/12 (20060101); A61B
18/08 (20060101); A61B 18/04 (20060101); F04B
43/12 (20060101); F24H 1/12 (20060101); A61F
7/00 (20060101); A61B 17/22 (20060101); A61B
17/00 (20060101); A61B 18/00 (20060101); A61F
007/12 () |
Field of
Search: |
;604/27,28,48,97.01,101.01,113,114,151-153 ;606/27,28,194
;607/105,126 |
References Cited
[Referenced By]
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Other References
Abstract, Kaver et al., "A New Transurethral Water-Induced Thermal
(WIR) Dilation Device for the Treatment of BPH," presented at SIU,
Sydney, Australia, Poster Session 26, BPH, Thermotherapy and
Hypothermia (Sep. 1994). .
European Search Report, Application No. EP 95 10 3189 dated Sep.
26, 1995. .
European Search Report, Application No. EP 97 10 6282 dated Dec. 7,
1999..
|
Primary Examiner: Nguyen; Anhtuan T.
Attorney, Agent or Firm: Myers Bigel Sibley & Sajovec,
P.A.
Parent Case Text
.[.RELATED APPLICATION
This application is for a continuation-in-part of my prior patent
application Ser. No. 07/669,366, filed Mar. 14, 1991 now U.S. Pat.
No. 5,257,977..].
Claims
What is claimed is:
1. Thermal treatment apparatus for thermally treating selected
tissues of a subject located in or near a body cavity, comprising a
catheter insertable into the subject's body cavity and including a
proximal end to be inserted into the body cavity, a distal end to
be located externally of the body cavity, .Iadd.an inflatable
anchoring balloon positioned adjacent said proximal end,
.Iaddend.and an inflatable heating section on said proximal end
.Iadd.axially away from said inflatable anchoring balloon in a
direction which is toward said distal end so as .Iaddend.to be
located near the tissue to be heated; said catheter being formed
with first and second passageways extending from said distal end to
said inflatable heating section and in fluid communication with
each other for circulating heated fluid through said inflatable
heating section .Iadd.and a third anchoring inflation passageway
extending from said distal end to said inflatable anchoring
balloon, said anchoring inflation passageway configured separate
from said first and second passageways, .Iaddend.and thermal
insulation, surrounding said first and second passageways from
close to said distal end to close to said inflatable heating
section, said thermal insulation including a plurality of separate
compartments containing a non-heated fluid, said components
extending axially along the catheter, whereby the inflatable
heating section and the tissue in its proximity may be heated to a
desired high temperature without correspondingly heating
non-selected tissues.
2. The apparatus according to claim 1, further including a heater
associated with said first passageway for heating a fluid, and a
pump associated with said heater and said second passageway for
circulating said fluid in a closed circuit through said heating
section of the catheter.
3. The apparatus according to claim 2, wherein said heater
includes: a heating block formed with a smoothly curved cavity; a
container defining a liquid reservoir and formed with a
complementary-curved wall removably receivable in said cavity; a
cover attached to said container; a liquid inlet tube passing
through said cover for inletting a liquid into said container to be
heated by said heating block; and a liquid outlet tube passing
through said cover for outletting a liquid from said container
after having been heated by said heating block.
4. The apparatus according to claim 3, wherein the dimensions of
said curved wall of the container are slightly smaller than those
of the smoothly curved cavity of the heating block, to provide a
small gap for receiving a liquid having good thermal coupling
characteristics.
5. The apparatus according to claim 3, wherein said smoothly-curved
cavity of the heating block, and said complementary-curved wall of
the container, are both of semi-spherical configuration.
6. The apparatus according to claim 3, wherein said heating block
is made of a material having high thermal conductivity and includes
at least one electrical heating element encased therein.
7. The apparatus according to claim 2, wherein said pump is a
peristaltic pump for pumping fluid through a peristaltic tube, said
pump including:
(a) a housing formed with a substantially cylindrical cavity having
an inner surface, said housing provided with a lid, said lid having
a depending skirt removably engagable within said cylindrical
cavity so as to form an inset lining around a part of said inner
surface; and
(b) a rotor rotatably mounted within said cylindrical cavity, said
rotor carrying rollers,
such that, when said depending skirt is not engaged in said
cylindrical cavity, the peristaltic tube may be easily inserted
between said rollers and said inner surface and, when said
depending skirt is engaged in said cylindrical cavity, the
peristaltic tube is engaged between said rollers and said inset
lining such that rotation of said rotor pumps fluid through the
peristaltic tube.
8. The apparatus according to claim 7, wherein an inner surface of
said depending skirt is formed with a groove to produce a pulsatile
fluid flow.
9. The apparatus of claim 1, further including a first thermal
sensor assembly associated with the inlet end of said first
passageway for measuring the temperature of the heated fluid
entering said first passageway; and a second thermal sensor
assembly associated with the outlet end of said second passageway
for measuring the temperature of the heated fluid exiting from said
second passageway.
10. The apparatus according to claim 9, wherein each of said
thermal sensor assemblies includes: a thermal sensor, a metal tube
connectable to the respective end of the respective passageway of
the catheter to receive the heated fluid flowing therethrough; a
metal thermal coupling member formed with a recess on one face for
receiving the thermal sensor therein, a recess on the opposite face
complementary to the shape of the metal tube for receiving the
metal tube therein, and a relatively thin web between the two
recesses; and a cover pressing said metal tube to said thermal
coupling member.
11. The apparatus according to claim 1, wherein said catheter
includes a .[.third.]. .Iadd.fourth .Iaddend.passageway extending
centrally of the catheter and communicating with an opening in the
proximal end of the catheter to drain liquid from the body cavity
to said distal end or to introduce a drug into the body.
12. The apparatus according to claim 1, wherein said heating
section of the catheter is of cylindrical configuration.
13. Thermal treatment apparatus for thermally treating selected
tissues of a subject located in or near a body cavity, comprising:
a catheter insertable into the subject's body cavity and including
a proximal end .Iadd.with a length which is .Iaddend.to be inserted
into the body cavity, a distal end to be located externally of the
body cavity, and an inflatable heating section .[.on.].
.Iadd.located along a portion of the length of .Iaddend.said
proximal end to be located near the tissue to be heated .Iadd.such
that it can be inserted and positioned in a desired location within
a body cavity; .Iaddend.first and second passageways
.Iadd.extending .Iaddend.from said distal end to said inflatable
heating section in fluid communication with each other .[.are.].
for circulating heated fluid through said inflatable heating
section; a first thermal sensor assembly associated with the inlet
end of said first passageway for measuring the temperature of the
heated fluid entering said first passageway; a second thermal
sensor assembly associated with the outlet end of said second
passageway for measuring the temperature of the heated fluid
exiting from said second passageway; and thermal insulation
surrounding said first and second passageways from close to said
distal end to close to said inflatable heating section, said
thermal insulation including a plurality of separate compartments
containing a non-heated fluid, said compartments extending axially
along .[.the.]. .Iadd.said .Iaddend.catheter.
14. The apparatus according to claim 13, wherein each of said
thermal sensor assembly includes: a thermal sensor; a metal tube
connectable to the respective end of the respective passageway of
the catheter to receive the heated fluid flowing therethrough; a
metal thermal coupling member formed with a recess on one face for
receiving the thermal sensor therein, a recess on the opposite face
complementary to the shape of the metal tube for receiving the
metal tube therein, and a relatively thin web between the two
recesses; and a cover pressing said metal tube to said metal
thermal coupling member..Iadd.
15. The apparatus of claim 1, wherein said body cavity is the
urethra and the tissue proximity to said inflatable heating section
is the prostate, and wherein, in position, said anchoring balloon
resides in the bladder of the subject proximate to the bladder
neck..Iaddend..Iadd.
16. The apparatus of claim 15, wherein responsive to inflation of
said heating section, said catheter inflatable heating section is
configured to expand and press against the prostate to enhance the
heating effects provided by exposing the tissue to heated fluid
circulating therein..Iaddend..Iadd.
17. The apparatus of claim 2, wherein said pump is configured to
provide a pulsatile flow output..Iaddend..Iadd.
18. The apparatus of claim 9, wherein said first and second thermal
sensor assemblies each include a metal tube portion configured to
allow the heated fluid to flow therethrough and which thermally
heat up in response to the heated fluid traveling
therethrough..Iaddend..Iadd.
19. The apparatus of claim 11, wherein said anchoring balloon is
inflated with air, and wherein the heated fluid circulating through
said inflatable heating section comprises water..Iaddend..Iadd.
20. The thermal treatment apparatus of claim 13, wherein each of
said first and second thermal sensor assemblies includes:
a thermal sensor
a metal tube in fluid communication with a respective one of the
inlet to said first passageway or the outlet to said second
passageway to allow the heated fluid to flow therethrough;
a metal thermal coupling member operably associated with said
thermal sensor and said metal tube which thermally couples said
metal tube and thermal sensor, wherein said metal thermal coupling
member is formed with a recess cavity configured to receive at
least a portion of said metal tube and hold same firmly therein
such that said metal tube abuts said recess
cavity..Iaddend..Iadd.
21. The thermal treatment apparatus of claim 20, said catheter
further comprising an anchoring balloon positioned on said catheter
intermediate said inflatable heating section and said proximal end,
and wherein said anchoring balloon is in fluid communication with a
third passageway which is in fluid isolation from said first and
second passageways..Iaddend..Iadd.
22. The apparatus of claim 21, wherein said body cavity comprises
the urethra, wherein the tissue in proximity to said inflatable
heating section is the prostate, and wherein, in position, said
anchoring balloon resides in the bladder of the subject proximate
to the bladder neck..Iaddend..Iadd.
23. The apparatus of claim 22, wherein, responsive to inflation of
said inflatable heating section, said catheter inflatable heating
section is configured to expand and press against the prostate to
enhance the heating effects provided by exposing the tissue to
heated fluid circulating therein..Iaddend..Iadd.
24. The apparatus of claim 23, wherein said catheter further
comprises a urinary drain port on said proximal end, said urinary
drain port including a drain channel which extends from said
proximal end to said distal end to allow urine to drain
therethrough..Iaddend..Iadd.
25. The apparatus of claim 24, wherein said thermal treatment
apparatus further comprises a pump in fluid communication with said
first and second passageways that circulates the heated fluid
therethrough, and wherein said pump is configured to provide a
pulsatile flow output..Iaddend..Iadd.
26. The apparatus of claim 24, wherein said anchoring balloon is
inflated with air, and wherein the heated fluid circulating through
said inflatable heating section comprises water..Iaddend..Iadd.
27. A thermal treatment system for thermally treating benign
prostatic hyperplasia, comprising:
a catheter configured to be inserted into the urethra of a subject,
said catheter having a length extending from a distal end to a
proximate end, said distal end located external of said subject
during use and said proximate end configured to reside in the
bladder of the subject during use, said catheter comprising;
an inflatable anchoring balloon configured to inflate and reside
against the bladder neck of the subject to hold said catheter in
position,
an inflatable heating section configured and sized to be positioned
adjacent prostate tissue to be heated during use, said anchoring
balloon and said inflatable heating section being arranged on said
catheter such that when said anchoring balloon is in position and
inflated to reside against the bladder neck, said inflatable
heating section is inflated to an expanded configuration such that
it firmly presses against the prostate tissue to enhance the
heating effects provided by contact with said inflatable heating
section;
an extension having a bladder drainage port positioned on said
proximate end of said catheter, said extension bladder drainage
port in fluid communication with a drainage passage extending along
the length of the catheter for allowing the bladder to drain urine
therethrough;
a first inlet passageway and a second outlet passageway extending
from said distal end of said catheter to said inflatable heating
section configured to circulate heated fluid therethrough;
a third passageway extending from said distal end of said catheter
to said inflatable anchoring section to direct an inflating fluid
thereto, said third passageway being separate from said first and
second passageways;
thermal insulation surrounding said first and second passageways
from close to said distal end to close to said inflatable heating
section, said thermal insulation comprising a plurality of separate
compartments containing a non-heated fluid, said compartments
extending axially along said catheter intermediate said distal end
and said inflatable heating section;
a liquid reservoir in fluid communication with said catheter;
a heater operably associated with said liquid reservoir;
a pump operably associated with said liquid reservoir and said
catheter for circulating heated fluid through said catheter;
a first thermal sensor operably associated with heated fluid
traveling into said first inlet passageway;
a second thermal sensor operably associated with heated fluid
traveling out of said second outlet passageway; and
a controller operably associated with said pump, said first thermal
sensor, said second thermal sensor, and said heater, wherein said
controller controls the operation of said heater and said pump in
response to temperatures associated with said heated circulating
fluid as sensed by said first and second thermal sensors,
wherein said thermal treatment system and said catheter are
configured to direct the circulating heated fluid to said prostate
to treat benign prostate hyperplasia by exposing tissue in the
prostate of the subject to a desired high temperature without
correspondingly heating non-selected tissues..Iaddend..Iadd.
28. A thermal treatment system according to claim 27, further
comprising first and second metal cylinder segments configured to
allow the heated fluid to flow therethrough, said first metal
cylinder in fluid communication with said first inlet passageway
and said second metal cylinder in fluid communication with said
second outlet passageway..Iaddend..Iadd.
29. A thermal treatment system according to claim 27, wherein said
inflatable heating section is configured as a cylindrical heating
section to radially expand from a first collapsed position to a
cylindrically shaped heating configuration having a first radial
width during use..Iaddend..Iadd.
30. A thermal treatment system according to claim 29, wherein said
inflatable anchoring balloon expands to a shape which has a second
radial width when inflated, said second radial width being larger
than said first radial width of said cylindrically shaped heating
section..Iaddend..Iadd.
31. A thermal treatment system according to claim 30, wherein said
catheter is configured to circulate heated water to thermally treat
the prostate by exposing same to heated water circulating in said
inflatable heating section without correspondingly heating
non-selected tissues..Iaddend..Iadd.
32. A thermal treatment system according to claim 31, wherein said
inflatable anchoring balloon is inflated by introduction of air
therein from said third passageway..Iaddend.
Description
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to thermal treatment apparatus for
thermally treating selected tissues of a subject. The invention is
particularly useful as a thermal treatment apparatus for treating
prostate, bladder and uterus, and is described below particularly
with respect to an apparatus for treating the prostate. The
invention also relates to a catheter construction, a heater, a
peristaltic pump, and a thermal sensor assembly, all especially
useful in the novel thermal treatment apparatus.
Thermal treatment is now a recognized form of treatment of certain
types of ailments including benign prostatic hyperplasia (BPH),
prostatitis, and prostate cancer. My prior U.S. application Ser.
No. 07/669,366, filed Mar. 14, 1991, now U.S. Pat. No. 5,257,977
discloses one form of thermal treatment apparatus including a
catheter insertable into the subject's urethra. The proximal end of
the catheter includes an inflatable anchoring section in the form
of a balloon to be anchored in the subjects bladder, and a heating
section which, when the balloon is so anchored, extends through the
subject's prostate. A heated liquid, such as water, is used to
inflate the balloon and is also circulated through the heating
section to heat the adjacent tissues of the prostate and the
bladder neck.
The present invention relates to this type of thermal treatment
apparatus but provides a number of important advantages, as will be
described more particularly below.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, there is provided a thermal
treatment apparatus for thermally treating selected tissues of a
subject located in or near a body cavity, comprising a catheter
insertable into the subject's body cavity and including a proximal
end formed with an inflatable anchoring section for anchoring the
catheter in the body cavity, a distal end to be located externally
of the body cavity, and an inflatable heating section adjacent the
proximal end to be located near the tissue to be heated. The
catheter is formed with first and second passageways extending from
the distal end to the, inflatable heating section for circulating
heated fluid through the inflatable heating section but not through
the inflatable anchoring section; and a third passageway from the
distal end to the inflatable anchoring section for inflating the
inflatable anchoring section with a non-heated fluid, whereby the
inflatable heating section and the tissue in its proximity may be
heated to a desired high temperature without correspondingly
heating the inflatable anchoring section and the tissue in its
proximity.
By thus inflating the anchoring section at the proximal end of the
catheter with a separate, non-heated fluid, the heating fluid may
be more particularly targeted, by the inflatable heating section,
to the tissue to be subjected to the thermal treatment, thereby
enabling higher temperatures to be applied if desired.
According to a another aspect of the invention, there is provided a
thermal treatment apparatus for thermally treating selected tissues
of a subject located in or near a body cavity, comprising: a
catheter insertable into the subject's body cavity and including a
proximal end having an inflatable anchoring section for anchoring
the catheter in the body cavity, a distal end to be located
externally of the body cavity, and an inflatable heating section
adjacent the proximal end to be located near the tissue to be
heated; first and second passageways from the distal end to the
inflatable heating section for circulating heated fluid through the
inflatable heating section but not through the inflatable anchoring
section; a first thermal sensor assembly near the inlet end of the
first passageway for measuring the temperature of the heated fluid
entering the first passageway; and a second thermal sensor assembly
near the outlet end of the second passageway for measuring the
temperature of the heated liquid exiting from the second
passageway.
More particularly, each of the two thermal sensor assemblies
includes: a thermal sensor, a metal tube connectable to the
respective end of the respective passageway of the catheter to
receive the heated fluid flowing therethrough; a metal thermal
coupling member formed with a recess on one face for receiving the
thermal sensor therein, a recess on the opposite face complementary
to the shape of the metal tube for receiving the metal tube
therein, and a relatively thin web between the two recesses; and a
cover pressing the metal tube to the metal thermal coupling
member.
According to a still further aspect of the invention, there is
provided a liquid heater which is particularly useful in such
thermal treatment apparatus and including a heating block formed
with a semi-spherical cavity; a container defining a liquid
reservoir and also formed with a semispherical wall removably
receivable in the cavity of the heating block; a cover attached to
the container; a liquid inlet tube passing through the cover for
inletting a liquid into the container to be heated by the heating
block; and a liquid outlet tube passing through the cover for
outletting a liquid from the container after having been heated by
the heating block.
According to a further aspect of the invention, there is provided a
peristaltic pump particularly useful in thermal treatment
apparatus, which peristaltic pump includes a housing formed with a
cylindrical cavity; and a rotor rotatably mounted within the cavity
and carrying rollers engageable with a peristaltic tube insertable
into the cavity for pressing the peristaltic tube against a wall of
the housing in order to pump a liquid through the peristaltic tube
during the rotation of the rotor; the wall of the housing including
a skirt depending from a lid removably received over the
cylindrical cavity; the depending skirt extending less than the
circumference of the lid to produce an interruption in the housing
wall against which the peristaltic tube is pressed by the rollers
of the rotor.
Further features and advantages of the invention will be apparent
from the description below.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with
reference to the accompanying drawings, wherein:
FIG. 1 is a block diagram illustrating the main components of a
thermal treatment apparatus constructed in accordance with the
present invention;
FIG. 2 is a view, partially in longitudinal section
diagrammatically illustrating one form of catheter constructed in
accordance with the present invention for use in the thermal
treatment apparatus of FIG. 1;
FIG. 3 is a view, partially in longitudinal section and rotated
90.degree. with respect to FIG. 2, illustrating the catheter of
FIG. 2;
FIGS. 4, 5 and 6 are transverse sectional views along lines IV--IV,
V--V and VI--VI in FIG. 3;
FIG. 7 is a bottom view illustrating one form of liquid heater
constructed in accordance with the invention for use in the thermal
treatment apparatus of FIG. 1;
FIG. 7a is a sectional view along line VIIa--VIIa of FIG. 7;
FIG. 8 is a longitudinal sectional view along line VIII--VIII of
FIG. 9, and FIG. 9 is a transverse sectional view along line IX--IX
of FIG. 8, of one form of peristaltic pump constructed in
accordance with the invention, FIG. 9a being a fragmentary detail
view along line IXa--IXa of FIG. 9;
FIG. 10 is a transverse sectional view along line X--X of FIG. 11,
and FIG. 11 is a longitudinal sectional view along line XI--XI of
FIG. 10, illustrating one form of thermal sensor assembly
constructed in accordance with the invention for use in the thermal
treatment apparatus of FIG. 1.
DESCRIPTION OF A PREFERRED EMBODIMENT
Overall Apparatus
The thermal treatment apparatus diagrammatically illustrated in
FIG. I includes a catheter 2 insertable into a subject's body
cavity to be treated thermally. In the example to be described
below, the heat is applied to treat the prostate. The catheter 2
would therefore be inserted into the subject's urethra, such that
one end of the catheter is anchored in the subject's bladder. This
locates a heating section of the catheter in the subject's
prostate.
The thermal treatment apparatus illustrated in FIG. 1 further
includes a heater 4 for heating a fluid, in this case a liquid such
as water, to be circulated in a closed circuit through the heating
section of the catheter by means of a pump 6, The temperature of
the heating liquid inletted from pump 6 into the catheter 2 is
measured by a thermal sensor assembly 8, and the temperature of the
liquid exiting from the catheter 2 to the heater 4 is measured by
another thermal sensor assembly 10. The illustrated apparatus
further includes a controller 12 which controls both the heater 4
and the pump 6 in response to the temperature sensed by sensor
assemblies 8 and 10 and another sensor (to be described below) in
the heater 4.
The construction of the catheter 2 is shown in FIGS. 2-6; the
construction of the liquid heater 4 is shown in FIGS. 7 and 7a; the
construction of the pump 6 is shown in FIGS. 8, 9 and 9a; and the
construction of the two thermal sensor assemblies 8 and 10 is shown
in FIGS. 10 and 11.
The catheter 2, as shown in FIGS. 2-6, includes a long slender tube
20 formed with an inflatable anchoring section 21 at the proximal
end for anchoring the catheter in the subject's bladder, and
thereby for locating an inflatable cylindrical heating section 22
extending through the subject's prostate when the catheter is so
anchored. The opposite end of the catheter, called the distal end,
is to be located externally of the subject's urethra so as to be
readily accessible for inflating the proximal anchoring section 21
and for inflating and circulating a heating liquid through the
inflatable heating section 22.
The heating liquid is circulated through the inflatable heating
section 22 via two passageways 24a, 24b having an inlet 25 and an
outlet 26 at the distal end 23 of the catheter. The inflatable
anchoring section 21 of the catheter is inflated by an unheated
fluid, such as air, introduced via an inlet 27 at the distal end 23
and communicating with the anchoring section 21 via the third
passageway 28 and an opening 29.
The portion of the catheter from the distal end 23 to the
inflatable heating section 22 is thermally insulated from the
subject's tissue by means of outer chambers 30, 30a and 30b
enclosing passageways 24a, 24b, referred to generically by numeral
24, through which the heating liquid is circulated to the heating
section 22. One of these chambers communicates with passageway 28
through which unheated air is applied to inflate the anchoring
section 21.
The catheter also includes an extension 31 at the proximal end,
which extension is received within the subject's bladder. Extension
31 is formed with an opening 32 for draining the subject's bladder
via a passageway 33 passing through the length of the catheter and
terminating in an outlet 34 at the distal end 23 of the catheter
for connection to a drain. Extension 31 and its passageway 33 may
also be used for introducing a drug into the bladder if
desired.
The Heater 4 (FIG. 7)
The liquid heater 4, as more particularly illustrated in FIG. 7,
includes a heating block 40 made of a good heat-conducting
material, such as aluminum. Heating block 40 is of dome shape to
define a smoothly curved semi-spherical cavity 41, and is
integrally formed with four perpendicular ribs 42. A plurality of
electrical heating elements 43, and one or more thermal sensors 44,
are encased within the heating block 40. As seen in FIG. 7, an
electrical heating element 43 is encased in each of the four ribs
42, and thermal sensor 44 is encased in each of the two opposite
sides of the heating block, midway between two heating elements 43.
The dome-shaped section of the heating block is relatively thin, as
shown at 45 in FIG. 7a, to thereby reduce its thermal mass.
The heating block 40 illustrated in FIG. 7a further includes a
removable container 50 serving as a water reservoir and formed with
a complementary-curved wall 51, i.e., of semi-spherical
configuration corresponding to the semi-spherical configuration of
cavity 41. The semi-spherical wall 51 of container 50, however, is
of slightly smaller dimensions than the heating block cavity 41 so
as to provide a small gap 52 adapted to receive a small quantity of
a liquid 53 to provide a good thermal coupling between block 40 and
container wall 51. The semi-spherical shape of the container wall
51 permits it to be of a thin- wall construction and therefore
sufficiently inexpensive so as to be disposable after one-time use.
The thinness of the plastic wall also provides good thermal
conductivity between heating block 40 and the interior of container
50.
Container 50 further includes a cover 54, preferably bonded by an
adhesive or solvent or welded to the curved wall 51 of the
container. Cover 54 is formed with a reentry tube 55 substantially
centrally of the cover for receiving an inlet tube 56 which inlets
into the container the liquid to be heated by the heating block 40.
A second reentry tube 57 is formed in cover 54 laterally Of reentry
tube 55, for receiving the outlet tube 58 which outlets the liquid
from the container. The inlet reentry tube 55 extends from cover 54
substantially to the bottom of the container 50, whereas the outlet
reentry tube 57 terminates close to the top of the container 50.
This arrangement provides a relatively large residence time and
contact surface for heating the liquid as it is circulated within
container 50 from the inlet 56 to the outlet 58.
The Peristaltic Pump 6 (FIGS. 8, 9 and 9a)
Pump 6 in FIG. 1 is a peristaltic pump as more particularly
illustrated in FIGS. 8, 9 and 9a. It includes a housing 60 formed
with a cylindrical cavity 61. Disposed within cylindrical cavity 61
is a rotor 62 connected by a drive shaft 63 to a gear motor (not
shown) and including a pair of spaced discs 64a, 64b rotatably
mounting between them a plurality (3) of rollers 65 within cavity
61. Also located within the cylindrical cavity 61 is a peristaltic
tube 66 which is engageable by the roller 65 for pumping the liquid
through the tube during the rotation of rotor 62. Assuming rotor 62
is rotated counter-clockwise in FIG. 9, the liquid will be pumped
through the peristaltic tube 66 from an inlet nipple 67 to an
outlet nipple 68.
As shown in FIG. 8, housing 60 further includes a lid 70 formed
with a large central opening 71 for accommodating disc 64 of the
rotor 62. Lid 70 is formed with a depending skirt 72 which extends
into the cylindrical cavity 61 such that the peristaltic tube 66 is
located between the inner surface of skirt 72 and the rollers 65.
Skirt 72 extends only for a part of the circumference of the lid,
e.g., from 160.degree. to 200.degree., to accommodate the inlet and
outlet ends of the peristaltic tube 66. As shown in FIG. 9, skirt
72 extends slightly more than 180.degree.; also, its leading edge
73 and its trailing edge 74 are tapered to provide a gradual
application of the pressure to the peristaltic tube by the roller
65, and a gradual release of the pressure.
Housing 60 is of polygonal, preferably square, cross-section to
provide a flat surface 60a. Lid 70 is provided with a depending pin
75 in contact with the outer flat surface 60a of housing 60 (see
FIGS. 9 and 9a) to prevent rotation of the lid during the rotation
of the rotor 62.
The illustrated construction, including the depending skirt 72,
facilitates the assembly of the peristaltic pump with the
peristaltic tube 66 between the skirt and the rollers 65. Thus,
with the lid removed the peristaltic tube 66 may be conveniently
applied around the rollers 65. The lid 70 may then be applied with
its skirt 72 received between the peristaltic tube 66 and the inner
surface of the cylindrical cavity 61 formed in housing 60, so as to
squeeze the tube between it and the rollers 65. For this purpose,
the lower edge of skirt 72 is tapered, as shown at 76 in FIGS. 8
and 9a, to facilitate the application of the skirt.
The foregoing construction not only facilitates the assembly of the
peristaltic pump, but also covers the rollers 65 to minimize
exposure to a person's fingers or the like. In addition, the
thickness of skirt 72 influences the outlet pressure produced by
the pump, so that lids 70 with different thickness skirts 72 may be
provided to provide different outlet pressures. In addition, the
inner surface of the skirt 72 may be provided with one or more
grooves, as shown at 77 in FIG. 9, to produce a pulsatile
output.
The thermal sensors assemblies 8, 10
The thermal sensor assemblies 8, 10 are more particularly
illustrated in FIGS. 10 and 11. They are both enclosed within a
common housing 80 in the shape of an "H" and closed by a common
cover 31. Thermal sensor assembly 8 near the inlet end of the
catheter 2 includes a thermal sensor element 82 received within a
rectangular recess formed in a metal thermal coupling member 83.
The opposite face of the coupling member is formed with a recess
for receiving a metal tube 84 connectable to an inlet tube 85 near
the inlet end of the catheter. Thermal sensor assembly 10 similarly
includes a therm.[.r.]. al sensor element 86 received within a
recess formed in another thermal coupling member 87. The opposite
face of member 87 is similarly formed with a recess for receiving a
metal tube 88 adapted to be coupled to an outlet tube 89 near the
outlet end of the catheter. Electrical connections are made to the
two thermal sensor elements 82 and 86 via a cable 90 leading to the
controller 12 in FIG. 1.
The two thermal coupling members 83, 87, as well as the two tubes
84, 88, are of a metal, such as stainless steel, having relatively
good thermal conductivity. The coupling members 83, 87 include
relatively thin web portions 83a, 87a, respectively, between the
thermal sensor elements 82, 86 and the metal tubes 84, 88, so as to
provide a good thermal coupling between the liquid flowing through
the two metal tubes and their respective thermal sensor elements.
The cover 81, fixed to the common H-shaped housing 80 in any
suitable manner, presses the metal tubes 94, 88 firmly against
their respective metal coupling members 83, 87.
Overall Operation
The overall operation of the thermal treatment apparatus
illustrated in the drawings is as follows:
The catheter 2 is inserted into the urethra of the subject until
the inflatable anchoring section 21 at the proximal end passes
through the subject's bladder neck. An unheated fluid, preferably
air, is introduced via inlet 27 and passageway 28 into the interior
of the anchoring section 21 to inflate it. This anchors section 21
in the subject's bladder, wherepon the cylindrical heating section
22 of the catheter extends through the subject's prostate.
A heating fluid, such as water, is then pumped from the container
50 via pump 6 into the inlet 25 of passageway 24a, to fill the
catheter and to inflate the cylindrical heating section 22 of the
catheter. Additional water is added to the catheter (e.g., via a
separate inlet in the connector connecting the catheter to the
closed circuit) to completely fill the closed circuit including
container 50 and the catheter 2. The water heated within container
50 is circulated by the peristaltic pump 6 through the closed
circuit including the cylindrical heating section 22 of the
catheter.
During the circulation of the heating liquid, the sensor assemblies
8, 10 sense the temperature of the heating liquid near the inlet
and outlet ends of the catheter, respectively. These sensor
assemblies, together with the thermal sensors 44 in the electrical
heater 4, control the controller 12 to maintain the desired
temperature. Only the inflated heating section 22 of the catheter
is effective to heat tissue, because of the thermal insulation
provided by the unheated air within the anchoring section 21 of the
catheter, and within chambers 30 of the remaining portion of the
catheter. Accordingly, the liquid applied to the inflatable heating
section 22 may be heated to a relatively high temperature for
application to the tissue within the prostate, with less danger of
unduly heating other tissue contacted by the catheter. The
inflation of the heating section 22 of the catheter also presses
that section firmly against the tissue to be thermally treated
thereby further enhancing the heating effects.
Drain opening 32 at the proximal end of the catheter, and
passageway 33 through the catheter, provide a drain for the bladder
liquids or enable the introduction of a drug into the bladder.
While the invention has been described with respect to one
preferred embodiment, it will be appreciated that many other
variations, modifications and applications of the invention may be
made.
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