U.S. patent application number 10/234505 was filed with the patent office on 2003-01-02 for therapeutic laser system operating between 1000 and 1300 nm and its use.
This patent application is currently assigned to CeramOptec Industries, Inc.. Invention is credited to Neuberger, Wolfgang, Schwarzmaier, Hans-Joachim.
Application Number | 20030004557 10/234505 |
Document ID | / |
Family ID | 24161751 |
Filed Date | 2003-01-02 |
United States Patent
Application |
20030004557 |
Kind Code |
A1 |
Neuberger, Wolfgang ; et
al. |
January 2, 2003 |
Therapeutic laser system operating between 1000 and 1300 nm and its
use
Abstract
Laser systems medical or cosmetic applications, comprising diode
lasers or diode lasers with other solid state lasers which can
deliver up to 30 cw or more, and which generally operate at more
than wavelength within the range of 1000 to 1300 nm are presented.
Individual emitter or emitter groups within the diode laser system
can be powered independently. These laser systems provide maximum
penetration depths for procedures such as Laser-induced
Interstitial Tumor Therapy, alone or in conjunction with other
therapies such as PhotoDynamic Therapy, chemotherapy, or radiation
therapy. Where beneficial for the procedure, the operating
wavelength of the system can be changed without interruption. In
some variants, active tissue cooling at the distal end of the
delivery fibers is incorporated as well as individual feedback
loops to control and stabilize the temperature induced in the
tissue. To enhance thermal or photo effects and thereby increase
efficiencies, absorbers can be administered and the laser system
tuned to the specific absorption band of the absorber.
Inventors: |
Neuberger, Wolfgang; (F.T.
Labuan, MY) ; Schwarzmaier, Hans-Joachim;
(Dusseldorf, DE) |
Correspondence
Address: |
CERAMOPTEC INDUSTRIES, INC.
515 Shaker Road
East Longmeadow
MA
01028
US
|
Assignee: |
CeramOptec Industries, Inc.
|
Family ID: |
24161751 |
Appl. No.: |
10/234505 |
Filed: |
September 4, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10234505 |
Sep 4, 2002 |
|
|
|
09541953 |
Apr 3, 2000 |
|
|
|
Current U.S.
Class: |
607/89 |
Current CPC
Class: |
A61B 18/22 20130101;
A61B 2017/00084 20130101; A61B 2018/00005 20130101; A61B 2018/2211
20130101; A61N 5/067 20210801; A61N 5/0601 20130101; A61N 2005/0659
20130101; A61N 5/062 20130101 |
Class at
Publication: |
607/89 |
International
Class: |
A61N 005/067 |
Claims
1. A diode laser system for medical and cosmetic therapeutic
treatments in the thermal regime comprising: at least one laser
diode emitter operating at a wavelength between 1000 nm and 1300 nm
and emitting sufficient power to thermally destroy tumors; and at
least one means to optically transmit said emissions to a treatment
site.
2. A diode laser system according to claim 1, further comprising:
at least one solid state laser source operating at a wavelength
between 1100 nm and 1300 nm.
3. A diode laser system according to claim 1, wherein said means to
optically transmit said emissions is selected from a group
consisting of an optical fiber and an optical waveguide.
4. A diode laser system according to claim 3, wherein said at least
one laser diode emitter is selected from the group consisting of at
least two single emitters and at least two emitter groups, and said
system further comprises one said means to optically transmit said
emissions connected to each said emitter/(emitter group).
5. A diode laser system according to claim 4, wherein said at least
one laser diode emitter has means to independently control each
said emitter/(emitter group).
6. A diode laser system according to claim 3, further comprising:
means to provide active treatment site cooling at a distal end of
said means to optically transmit said emissions.
7. A diode laser system according to claim 4, wherein each said
emitter/(emitter group) has its own individual feedback loop to
control and stabilize induced temperature at a treatment site.
8. A diode laser system according to claim 1, wherein said emission
wavelength is selectively variable within a specified range without
interrupting a therapeutic procedure.
9. A medical or cosmetic therapeutic treatment using a diode laser
system according to claim 1, comprising a step of selecting said
treatment from a group consisting of coagulating, denaturing and
shrinking tissue.
10. A medical or cosmetic therapeutic treatment according to claim
9, further comprising pretreatment steps of: administering an
absorber; tuning said laser system to a specific absorption band of
said absorber.
11. A medical or cosmetic therapeutic treatment according to claim
9, further comprising a step of: administering a chemotherapy
treatment.
12. A medical or cosmetic therapeutic treatment according to claim
10, further comprising a step of: administering a chemotherapy
treatment.
13. A medical or cosmetic therapeutic treatment according to claim
9, further comprising a step of: administering a radiation therapy
treatment.
14. A medical or cosmetic therapeutic treatment according to claim
10, further comprising a step of: administering a radiation therapy
treatment.
15. A medical or cosmetic therapeutic treatment in the thermal
regime using a diode laser system comprising at least one laser
diode emitter operating at a wavelength between 1000 nm and 1300 nm
and emitting sufficient power to thermally destroy tumors and at
least one means to optically transmit said emissions to a treatment
site, comprising the steps of: selecting said treatment from a
group consisting of coagulating, denaturing and shrinking tissue;
and administering a chemotherapy treatment.
16. A medical or cosmetic therapeutic treatment according to claim
15, further comprising pretreatment steps of: administering an
absorber; and tuning said laser system to a specific absorption
band of said absorber.
17. A medical or cosmetic therapeutic treatment in the thermal
regime using a diode laser system comprising at least one laser
diode emitter operating at a wavelength between 1000 nm and 1300 nm
and emitting sufficient power to thermally destroy tumors and at
least one means to optically transmit said emissions to a treatment
site, comprising the steps of: administering an absorber; tuning
said laser system to a specific absorption band of said absorber;
selecting said treatment from a group consisting of coagulating,
denaturing and shrinking tissue; and administering a radiation
therapy treatment.
18. A medical or cosmetic therapeutic treatment according to claim
15, further comprising a step of: providing active treatment site
cooling during said treatment.
19. A medical or cosmetic therapeutic treatment according to claim
15, further comprising a step of: controlling and stabilizing
induced temperature at said treatment site by means of a feedback
loop associated with each emitter (emitter group).
20. A medical or cosmetic therapeutic treatment in the thermal
regime using a diode laser system comprising at least one laser
diode emitter operating at a wavelength between 1000 nm and 1300 nm
and emitting sufficient power to thermally destroy tumors and at
least one means to optically transmit said emissions to a treatment
site, comprising the steps of: administering an absorber; tuning
said laser system to a specific absorption band of said absorber;
selecting said treatment from a group consisting of coagulating,
denaturing and shrinking tissue; and administering said treatment
in combination with a radiation therapy treatment.
21. A medical or cosmetic therapeutic treatment according to claim
20, further comprising a step of: varying said emission wavelength
selectively within a specified range without interrupting said
therapeutic treatment.
22. A medical or cosmetic therapeutic treatment according to claim
20, further comprising a step of: providing active treatment site
cooling during said treatment.
23. A medical or cosmetic therapeutic treatment according to claim
20, further comprising a step of: controlling and stabilizing
induced temperature at said treatment site by means of a feedback
loop associated with each emitter (emitter group).
Description
REFERENCE TO RELATED CASE
[0001] This application is a continuation of co-pending U.S. patent
application 09/541,953 filed on Apr. 3, 2000 by Wolfgang Neuberger
and H-J. Schwarzmaier, inventors, entitled "Therapeutic Laser
System Operating Between 1000 and 1300 nm and its Use", and
incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The field of the invention is diode laser systems used for
medical or cosmetic treatments in the thermal regime alone or in
conjunction with other therapies such photodynamic therapy,
chemotherapy or radiation therapy.
[0004] 2. Information Disclosure Statement
[0005] A lot of different tumor types, located in various parts of
the body have been successfully treated with lasers in the recent
years. In this way, lasers have also been used for the thermal
destruction of tumors. This therapy is called laser-induced
interstitial tumor therapy (LITT). The target tissue (a tumor) is
irradiated with laser light using a specially designed light guide
ending in an adequate applicator (e.g. cooled optical
diffuser).
[0006] The light generated by a laser is absorbed selectively by
tissue, because of its monochromatic and coherent nature. This
absorption is dependent on the physical properties of the tissue,
which include absorption and scattering. These properties depend on
the wavelength of the incident laser light. Absorption in tissue is
mainly characterized by water absorption, because in the infrared
region there is a very large and sharp vibrational absorption band
for water.
[0007] The laser light absorbed by the tissue is leading to heating
of the target volume. The resulting thermal damage leads to the
destruction of the tumor. The primary effect here is the direct
coagulation of the irradiated tissue, while temperature dependent,
also other mechanisms are described (e.g. hyperthermia).
[0008] Up to now the therapy was conducted with Nd-YAG lasers. This
laser was used because there is a local absorption minimum in water
at 1050 nm. At this wavelength the laser light is absorbed mainly
by blood and not by water. This leads to a penetration depth, which
is sufficient for a successful therapy. This means that the laser
light penetrates a certain depth into the tissue before it is
absorbed. Although the Nd-YAG laser is commonly used for
interstitial tumor therapy, the use of this single wavelength is
based primarily on the fact, that no other lasers in this
wavelength range were available. Additionally this type of laser
requires a lot of maintenance and costly techniques.
[0009] Due to new developments this limited approach can be
overcome. Diode laser light sources will now be available in the
wavelength range of 1000 nm up to 1300 nm. These laser are almost
maintenance free and easy to use.
[0010] Additionally studies based on recent measurements
surprisingly show that the maximum penetration depth is not located
at a wavelength of 1064 nm, but in the wavelength range of 1100 nm
to 1150 nm. These measurements take into account, that the
penetration depth is not only dependent on the absorption of water.
For this the absorption and scattering of the other ingredients of
tissue also have to be taken into account. A measurement of the
absorption and scattering properties of tissue (for example in
brain tumors as described below) show that the penetration depth in
the entire wavelength range of 1000 nm up to 1300 nm is similar to
that at 1064 nm with a maximum from 1100 nm to 1150 nm.
Consequently these wavelengths are also very suitable to be used
for the LITT. This wavelength region has not been used in the prior
art, because no adequate laser light sources (with powers of 30 W
cw) were available until now.
[0011] Large penetration depths are especially important for cooled
LITT (U.S. Pat. No. 5,989,246 and 5,861,020). These systems are
used to cool the area surrounding the applicator. Therefore, a
larger power can be applied without inducing carbonization or
vaporization in this area. This results in even bigger lesion
sizes. Having maximum penetration depths would thus help treat
large areas, quicker and with less treatments.
[0012] During the coagulation process the denaturation of the
proteins leads to a change of the physical properties (optical,
thermal, perfusion, . . . ). Usually the denaturation leads to
higher scattering and lower absorption in tissue. This means that
the penetration depth will change. A large penetration depth could
then be achieved by increasing the wavelength of the used laser.
Therefore, it may be required to change the laser wavelength, as a
consequence of the coagulation process.
[0013] The limitation to only one wavelength, in the current art,
presents a number of drawbacks. The Nd-YAG equipment used by
physicians in the clinics today are quite bulky and require a lot
of maintenance. Moreover the laser and the wavelength used right
now does not allow the maximal penetration depth, which could be
achieved with laser diodes. Additionally by adjusting the
wavelength one would be able to adapt to the different optical
properties of different tissue types, and thereby achieve the best
success in therapy. Having multiple wavelengths available in a
compact diode laser package would allow the possibility of a
combination with other existing therapies which could lead to new
therapeutic techniques. Thus far however diode lasers operating
above 1000 nm have not been available.
SUMMARY AND OBJECTIVES OF THE INVENTION
[0014] It is therefore an object of this invention to provide a
novel family of laser systems comprising diode lasers or diode
lasers with other solid state lasers for performing medical or
cosmetic procedures such as Laser-induced Interstitial Tumor
Therapy (LITT) treatments on large tumors or ones needing high
penetration depths, and which can operate at more than one
wavelength in the wavelength range of 1000 nm to 1300 nm and more
optimally between 1100 to 1300 nm.
[0015] It is another object of this invention to provide diode
laser systems with at least two emitters or emitter groups, each of
which is coupled to an optical fiber or waveguide.
[0016] A further object of this invention is to provide a diode
laser system where each single emitter or emitter group can be
individually controlled in power.
[0017] A still further object of this invention is to incorporate
within the system means to provide active tissue cooling at the
distal end of the fibers or waveguides and/or to provide individual
feedback loops for each single emitter or emitter group to control
and stabilize the temperature induced in the tissue.
[0018] Yet another object of this invention is to provide a method
for a surgical or cosmetic laser procedure, such as laser-induced
interstitial tumor therapy, using a diode laser system operating at
wavelengths between 1000 nm and 1300 nm and where delivery to
interior sites employs interstitial fibers or waveguides.
[0019] Still another object of this invention is to provide a
method for a surgical or cosmetic laser procedure which can be
combined with chemotherapy or radiation therapy to enhance the
therapeutic effects of both therapies.
[0020] Another object of this invention is to provide a laser
system which can be tuned to the absorption band of an absorber,
which has been introduced to the treatment site prior to
irradiation.
[0021] Briefly stated the present invention provides laser systems
for medical or cosmetic applications, comprising diode lasers or
diode lasers with other solid state lasers which can deliver up to
30 cw or more, and which generally operate at more than wavelength
within the range of 1000 to 1300 nm. Individual emitter or emitter
groups within the diode laser system can be powered independently.
These laser systems provide maximum penetration depths for
procedures such as Laser-induced Interstitial Tumor Therapy, alone
or in conjunction with other therapies such as PhotoDynamic
Therapy, chemotherapy, or radiation therapy. Where beneficial for
the procedure, the operating wavelength of the system can be
changed without interruption. In some variants, active tissue
cooling at the distal end of the delivery fibers is incorporated as
well as individual feedback loops to control and stabilize the
temperature induced in the tissue. To enhance thermal or photo
effects and thereby increase efficiencies, absorbers can be
administered and the laser system tuned to the specific absorption
band of the absorber.
[0022] The above, and other objects, features and advantages of the
present invention will become apparent from the following detailed
description read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 displays the absorption of water.
[0024] FIG. 2 shows the absorption of a human brain tumor
(meningeoma).
[0025] FIG. 3 shows the scattering of a human brain tumor
(meningeoma).
[0026] FIG. 4 shows the anisotropy of a human brain tumor
(meningeoma).
[0027] FIG. 5 shows the penetration depth of a human brain tumor
(meningeoma).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The new development of diode lasers, operating in the range
of 1000 to 1300 nm region, offers a new laser light source which is
suitable to be used for LITT and other medical or cosmetic
treatments. These lasers now can be built small in size, and are
reliable in practice; and they are now available for a large number
of wavelengths in the desired operating range.
[0029] Another aspect of this invention is the change of the
wavelength during the therapy. Changing the wavelength during the
therapy will lead to maximal penetration depth at all times during
the operation, although the optical properties change during the
operation.
[0030] Laser systems for these therapies consist of laser diodes,
which are capable of varying their wavelength in the desired range,
or alternatively have two or more diode lasers to cover the
wavelength range of 1100 nm to 1300 nm, needed for an effective
therapy.
[0031] Another embodiment of this invention is the possibility to
combine more than one applicator (treatment fiber) to be able to
treat tumors bigger that 5 cm. One possibility is to distribute the
laser power equally on all used applicators. Another option would
be to apply different powers to each of the used applicators.
Currently the laser power can be delivered from the source over a
beam splitter to the treatment fibers. A new possibility, which
allows to adjust the power delivered to each treatment fiber, is to
use different diode lasers, one for each treatment fiber connected
to the laser with a multi-fiber connector. This connector can
connect simultaneously two or more treatment fibers to the
appropriate laser source. The treatment fibers then combine to one
triple-fiber and finally split up again shortly before they reach
the treatment area. This new option is useful if large or
asymmetric tumors are to be treated.
[0032] Another embodiment of the invention would have an individual
feedback loop with each applicator to measure the achieved
temperature in the tumor. This can be used for regulation and
stabilization during the therapy process. The laser source has a
control input, which is used to control the laser power output. The
signal of the feedback loop reports for example on the actual
temperature in the tissue, and can be used to adjust the laser
power. This control can be done by a personal computer, which
receives the mentioned temperature data and reduces or increases
the laser power to have a constant temperature in the tissue during
the therapy.
[0033] The therapy performed in the wavelength range mentioned
above can be applied to all operations where tissue has to be
coagulated or to be shrunk. These therapies include cancer
treatment, for example brain tumors as mentioned above or liver
tumors. Of course benign prostate hyperplasia can also be treated
with this technique. One could think of irradiating collagen and
cartilage as well. Treatment of corresponding diseases of animals
are possible also.
[0034] The new features of this invention including the novel
attributes and use of combination of parts are now described in
detail for a specific example.
[0035] In FIG. 1 the absorption of water is shown as a function of
the incident wavelength. A first absorption peak is located
approximately at 980 nm. Going to higher wavelength there is a
local minimum at 1050 nm, where the currently used Nd-YAG laser
emits laser light. After this the water absorption is strongly
ascending. Since this is not enough to determine the penetration
depth in tissue one has to take a look at the following
measurements of the optical properties of tissue, too.
[0036] As one example the absorption coefficient of human brain
tumor (meningeoma) is shown as a function of the wavelength in FIG.
2. The absorption of this type of tissue is low in the visible
wavelength range. In the near infrared including 1064 nm there is a
slight rise in absorption until 1150 nm, after that are some local
minimums between 1200 and 1300 nm. Finally the absorption of this
type of tumor is rising strongly from 1350 nm. This means that if
only absorption would be present the penetration depth would be
bigger in the range of 1200 nm to 1300 nm. The range of 800 to 950
nm would not be of use, because absorption in this range is so low,
that no significant heating would occur. To have a complete view
one has to take scattering into account, too. The scattering shown
in FIG. 3 is getting lower with rising wavelength. This means that
if only scattering would be present the penetration depth would be
bigger for longer wavelengths. The last considered value is the
anisotropy factor shown in FIG. 4 which roughly speaking determines
the direction of scattering. The values of the anisotropy are
roughly uniform in the mentioned wavelength range.
[0037] To obtain the ideal wavelength range one has to combine
these three observations. FIG. 5 shows the resulting penetration
depth. One can easily see, that the penetration depth is almost
uniform in the range of 1000 nm up to 1300 nm, with a maximum
between 1100 and 1150 nm. This wavelength range should be used, if
maximal penetration depth and maximal lesion sizes need to be
induced in tissue.
[0038] For many treatments, applications either a single emitter or
a group of emitters may function as a unit having one emitting
wavelength, activating one process in a tissue or additive such as
an absorber or photosensitizer. The group of emitters might be a
diode laser bar or a portion of a bar which can be independently
powered and thus controlled.
[0039] Having described some preferred embodiments of the invention
with reference to the accompanying drawings, it is to be understood
that the invention is not limited to the precise embodiments, and
that various changes and modifications may be effected therein by
skilled in the art without departing from the scope or spirit of
the invention as defined in the appended claims.
* * * * *