CA1086172A - Surgical instrument having self-regulating radiant heating of its cutting edge and method of using the same - Google Patents
Surgical instrument having self-regulating radiant heating of its cutting edge and method of using the sameInfo
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- CA1086172A CA1086172A CA246,549A CA246549A CA1086172A CA 1086172 A CA1086172 A CA 1086172A CA 246549 A CA246549 A CA 246549A CA 1086172 A CA1086172 A CA 1086172A
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- Prior art keywords
- blade
- radiant
- cutting edge
- energy
- cutting
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
- A61B18/08—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by means of electrically-heated probes
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
- A61B18/08—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by means of electrically-heated probes
- A61B18/082—Probes or electrodes therefor
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
- A61B18/20—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser
- A61B18/22—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser the beam being directed along or through a flexible conduit, e.g. an optical fibre; Couplings or hand-pieces therefor
- A61B18/28—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser the beam being directed along or through a flexible conduit, e.g. an optical fibre; Couplings or hand-pieces therefor for heating a thermal probe or absorber
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B2018/00053—Mechanical features of the instrument of device
- A61B2018/00107—Coatings on the energy applicator
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- Health & Medical Sciences (AREA)
- Surgery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- General Health & Medical Sciences (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Veterinary Medicine (AREA)
- Public Health (AREA)
- Otolaryngology (AREA)
- Heart & Thoracic Surgery (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Animal Behavior & Ethology (AREA)
- Plasma & Fusion (AREA)
- Thermal Sciences (AREA)
- Optics & Photonics (AREA)
- Electromagnetism (AREA)
- Surgical Instruments (AREA)
- Laser Surgery Devices (AREA)
Abstract
Abstract of the Disclosure The cutting edge of a scalpel blade is heated to an elevated preselected constant operating temperature for cutting tissue with simultaneous hemostasis by radiant heating of the blade in the region along the cutting edge.
Radiant energy is contained within the blade by a reflec-tive coating over the transparent or translucent blade material. Heating along the cutting edge is provided by the disposition of a radiation-absorptive material beneath the reflective coating in the region along the cutting edge. Selective heating of regions of the cutting edge that are locally cooled by contact with tissues during surgical cutting is provided for by fabricating the radia-tion-absorptive element of the blade of a thermochromic material that exhibits a substantial increase in absorp-tion coefficient for a temperature decrement within the operating temperature range.
Radiant energy is contained within the blade by a reflec-tive coating over the transparent or translucent blade material. Heating along the cutting edge is provided by the disposition of a radiation-absorptive material beneath the reflective coating in the region along the cutting edge. Selective heating of regions of the cutting edge that are locally cooled by contact with tissues during surgical cutting is provided for by fabricating the radia-tion-absorptive element of the blade of a thermochromic material that exhibits a substantial increase in absorp-tion coefficient for a temperature decrement within the operating temperature range.
Description
z SURGICAL INSTRUMENT HAVING S~LF-REGULATING
~ADIANT HEATING OF ITS CUT~ING EDGE
AND_METHOD OF USING THE SAME
Back~round of the Invention The control o~ bleeding during surgery accounts for a major portion of the total time involved in an operation. The :
bleeding that occurs from the plethora of small blood vessels that pervade all tissues whenever tissues are incised obscures the surgeon's vision, reduces his precision, and often dictates slow and elaborate procedures in surgical opera~ions. It is well known to heat the tissues to minimize bleeding from in-cisions, and surgical scalpels which are designed to elevate ~:
tissue temperatures and minimize bleeding are also well known.
One such scalpel transmits high frequency, high energy sparks from a small electrode held in the surgeon's hand to the tissues, where they are converted to heat. Typically, substantial ., ~'~ .
3L7;2 electrical currents pass throuyh -the patient's body to a lar~e electrode beneath the pa-tient, which completes the electrical circuit. Discharge of sparks and temperature conversion in the tissue are poorly controlled in distribution and intensity, and erratic muscular contractions in the patient are produced so that this apparatus cannot be us~d to perform precise surgery.
Further, apparatus of this type frequently produce severe tissue damage and debris in the form of charred and dead tissue, which materially interfere with wound healing.
Another well-known surgical scalpel employs a blade with a resistive heating element which cuts the tissue and pro-vides simultaneous hemostasis. Although these resistive elements can be readily brought to a suitably high and constant temper-ature iTI air prior to contacting tissues, as soon as portions of the blade~come in contact with tissues, they are rapidly cooled.
During surgery, non-predictable and continuously varying portions ~ -: -:
of the blade contact the tissues as they are being cut. As the blade cools, the tissue cutting and hemostasis become markedly less effective and tissue tends to adhere to the blade. If additional power is applied by conventional means to counteract this cooling, this additional power is selectively delivered to the uncooled portions of the blade r frequently resulting in excessive temperatures which may result in tissue damage and blade destruction. This results from the fact that in certain ;
known resistively heated scalpels, the heating is a function of the current s~uared times the resistance (I2~). In conventional metallic blades of this type, the higher the temperature of any -blade portion, the greater its electrical resistance, and con-sequently the greater the incremental heating resulting from incremental power input. ' -~
It is generally recognized that to seal -tissues and effect hemostasis it is desirable to operate at a temperature between 300C. and 1000C. ~nd for reasons noted above, it is desirable that electrothermal hemostatic surgical cutting instruments include a mechanism by which power is selectively delivered to those portions of the cutting edge that are cool-ed by tissue contact so that the blade may be maintained at a substantially uniform operating temperature within the desired optimal range. Recently, hemostatic scalpels have been des-cribed (see, for example, V. S. Patents 3,768,482 and 3,826,263) in which the temperature-controlling mechanisms include resistive heating elements disposed on the surface of the scalpel blade. However, such instruments require pre-cision in fabricating the dimensions of the heating elements to obtain the desired resistances. And such resistive heat-ing elements may be subjected to variations in resistance during use, as tissue juices and proteins become deposited upon ~le surface of the blade.
_ mmary of the In~ention In accordance with one aspect of this invention there is provided a blade comprising: cutting means includ-ing a cutting edge, said cutting means being substantially transparent to radiant energy applied through said cutting means to said cutting edge; and a radiant-energy absorptive means disposed in the region of said cutting edge.
In accordance with another aspect of this invention there is provided the method of heating the cutting edge of a blade means operating at an elevated temperature, the method comprising: introducing radiant energy into a~sub stantially transparent blade means; and absorbing radiant energy in the region of the cutting edge.
~ -3-. . ~
By way oE ~dded explanation, -tlle present inven~ion provides ~ sur~ical cutting instrument in which the cutting portion of the blade is brought to an elevated temperature by radiant heating of the internal struc-tures of the blade~
Radiant energy from a source such as a high temperature fila ment or ribbon or a laser is optlcally coupled to a substantial-ly transparent blade-shaped structure, one edge of which has been sharpened to form the cutting edge of the instrument.
A non-transmitting internally-re~lecting surface prevents loss Of radiant energy from within the blade. The resultant scattering of light by internal reflections tends to distribute radiant energy throughout the blade, and the optical scattering ~ ;
may be further enhanced by the incorporation of particulate scattering elements within the blade material.
.
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Beneath the internally-re~lectin~ coating and c)nly alony the cutting edge o~ the blade, there is disposed a radiation-absorbing material which absorbs and converts the radiant energy to heat which is conducted through the material to the cutting edge to bring it to operating temperatures. The average temper-ature along the cutting edge may be adjusted by adjusting the power supplied by the radiation source, for example, by adjusting the electrical signals applied thereto.
Sel~ctive heating of those portions of the cutting edge that are cooled by tissue contact in order to maintain cutting temperatures sufficiently constant (i.e., temperature self-regulation) may be accomplished by fabricating the radiation absorber in the region of the cutting edge of a material which substantially increases in absorption coefficient with decreasing temperature within the operating temperature range. Since each local region of the material absorbs the distributed radiation in accordance with its local absorption coefficient, each local region may have its temperature regulated independently of the operating temperature of adjacent regions. Thus, even in the presence of unpredictable and substantial variations in the , cooling of the various regions of the heated edge resulting from the edge being manipulated to cut tissues, all regions along the ;
length of the cutting edge can be maintained within a suitably constant temperature range. Knvwn thermochromic materials which , have absorption coefficients that vary as a function of temper-I ature may be used as the radiation-absorbing material in the surgical instrument of the present invention.
De_cription of the Drawings Figure 1 is a partial side view of a surgical cutting instrument according to one embodiment of the present invention;
: ' Figure 2 is an end view of the apparatus o~ Figure 1 showing the blade-like element and the radiation source therein;
Figure 3 is a partial side view of an alternative embodiment of the present invention;
Figure 4 is an end view of the apparatus of Figure 3 .~ showing the optical channels therein for distributing radiation from a remote source; and . :
Figure 5 is a partial side view of another embodiment :~ which employs segmented thermochromic regions. `:
:: 10 Description of the Preferred Embodiment . Referring now to Figure 1, there is shown a partial ~
side view of a surgical cutting instrument which has a blade- ::
:` like element 9 that is suita~ly attached to handle 11. A high-intensity light or radiation source within the handle 11 in-~ cludes a lineally-mounted incandescent filament or ribbon 13 ;~ that is disposed within a parabolic reflector 15 which is oriented .' to direct the radiant energy ~rom the filament toward the cutting ~`, edge 17 and facets 16 at the lower portion 18 of the blade. The lineally-mounted filament 13 assures adequate distribution of the radiant energy therefrom substantially over the length of the cutting edge 17 of blade 9. The electrical power to heat the filament 13 is applied thereto by A.C. or D.C. source 20 via conductors 21 and 22. A photodetector 30 is optically coupled to the internal structure of the blade 9 and is electrically ~ :
coupled to the power source 20 through a conventional servo-regulator means 31 in a manner which controls the average power applied to the filament 13 in response to the level of radiant flux detected by photodetector 30.
Referring now to Figure 2, there is shown a cross ;~-~
section of the apparatus of Figure 1 inLLuding the filament 13 L7;i~
and the reflector 15 that directs radiant flux 5 substantially toward the facets 16 and cutting edge 17 of the balde 9. The filament 13, parabolic reElector 15 and radiation~transmitting window 14 may be formed into a chamber which is evacuated or filled with inert gas to minimize oxidation of the incandescent filament 13. The material of blade 9 should transmit and scatter well the radiant energy at the wavelengths of flux 5 from fila-ment 13 but should absorb poorly or not at all at these wave-lengths. A reflective optical coating 8 is disposed over the parabolic reflector and over the internal surfaces of the blade ; side walls 6 and 7 and the facets 16 of blade 9, but not over the window 14 through which the flux from the filament 13 is coupled to the blade 9. A layer 10 of radiation-absorbing, thermo-chromic material is disposed at the facets 16 of blade 9 adjacent the reflective coating 8 and acts as a collector of the radiant ; flux 5 from filament 13. The radiant flux 5 collected in layer ;~
10 is converted to heat which is conducted to the cutting edge 17.
Thermochromi¢ materials which havP absorption coefficients that vary as a function of temperature may be used as the radiation-absorbing material of layer 10. Materials which exhibit thermochromic properties in selected temperature ranges include indium antimonide, gallium antimonide, and other semiconductors, zinc oxide, some lead salts, and other inorganic and organic materials.
Only a portion of the radiation which illuminates the absorbing material of layer 10 is absorbed. ~he remaining non-absorbed portion of the radiation is transmitted through the layer 10 and i5 internally reflected by the reflective coating 8 back through the layer 10 (where further absorption occurs) and 3Q re-emerges in the relatively transparent region 9 of the blade :~:
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6~2 which is remote from the cutting edge where it follows a multi-reflective distribution path. As the temperature of the absorbing material 10 and hence oE the cutting edge 17 increases, absorption by the material of layer 10 decreases and the average radiant flux in the transparent region ~ of the blade increases.
Conversely, as the heated regions o~ the cutting edge 17 cool upon contact with tissue heing cut, radiation absorption by the material of layer 10 increases and the average radiant flux in the transparent region 9 of the blade decreases. ~he radiant-energy detector 30 may be coupled to the interior of the bladefor monitoring the average radiant flux within the blade to in-crease or decrease the power supplied by the source 20 to the radiation source 13 as required.
Absorption by layer 10 of the wavelengths of radiant energy produced by filament 13 thus experiences increments for temperature decrements within the operating range of the cutting edge, from 300C. to 1000C. It is this radiation absorption - property of the material of layer 10 that provides the self-regulating means by which local regions of the cutting edge 17 that cool upon contact with tissue being cut are radiantly heated by increased absorption of radiation. Other local regions of the cutting edge not cooled upon contact with tissue being cut do not exhibit increased absorption and therefore do not substantially change in their conversion of radiant energy to heat. Thus, as the temperature varies in various regions of facets 16 and the layer 10 disposed thereon, the radiation absorption of these re-gions varies inversely to assure increased radiation absorption of the cooled regions sufficient to maintain the operating 29 temperature thereof within the desired operating range.
z ~ s the layer lO and cutting edge 17 heat up prior to cutting, the layer lO becomes less absorptive and higher levels of radiant flux 5 are reflected from layer lO or are transmitted through layer lO to be internally reflected by the reflecting surface 8. This increases the light flux within the relatively transparent material such as glass or quartz, or th~ like, of blade 9. Radiation scattering centers such as rutile fibers, ~uartz particles, or the like, may be dispersed through the region 9 o~ the blade. The increased light flux in region 9 is detected by detector 30 which is coupled through a conventional .. ~
servo-regulator 31 to the power source 20 to decrease the power ~:
` supplied to ~ilament 13. The temperature of layer 10 and cutting edge 17 and facets 16 is thus stabilized within a preselected operating range. Conversely, as portions of the cutting edge 17 and facets 16 are cooled upon contact with tissue being cut, the material of layer lO in the locally-cooled regions increases the absorption of radiant flux and decreases the level of flux in the portion of blade 9 sensed by detector 30, and this acts through servo-regulator 31 to increase the power supplied by power source 20 to the filament 13. Where it is desirable to .:
maintain a relatively uniform wavelength spectrum of radiant energy over the dynamic range of power dissipation of the cutting instrument, the amount of surface area of the filament 13 heated to a specified temperature may be varied, as by retracting into the handle, or rotating within an aperture to vary the amount of radiant flux, rather than varying the temperature of the filament operating with a fixed, exposed area.
Alternatively, a relatively fixed spectrum can be accomplished by utili2ing a filter between w~ndow 14 and the blade.
Such a filter may also be used to narrow the bandwidth of the ..
.: '. :
radiant energy, and there~y simplify the selection of absorbing materials used in layer 10 or, the ilament 13 may he replaced by the ionized gas column of a gas discharge tube which emits radiant energy within one or a few characteristically narrow spectral lines) and which thus also simplifies the selection of absorbing materials used in layer 10.
Referring now to Figures 3 and 4, there are shown side and end views, respectively, of an alternative embodi~ment of the present invention in which the radiant source is disposed re-motely from the cutting instrument. Light pipe elements such as fiber optic filaments 33 are aligned in a linear array to irradiate the absorbing layer 10. A photodetector 30 may be disposed within the handle 11 to detect the level of radiant flux and to produce a control signal on line 35 in response thereto for controlling the power output from the remote source 37, such as a laser. Alternatively, selected fibers in the array 33 can be used to sample radiant flux at locations along the length of the blade and illuminate a remote photodetector, thereby to produce the requisite power~controlling signal ~lso, other optical means such as reflective mirrors and lenses .
may be used instead of the optical fibers to couple the radiant energy from the remote source into the absorbing layer 10.
Figure 5 illustrates still another embodiment of the present invention in which the material of the absorbing layers lOa, lOb, lOc, etc. e~hibits relatively constant absorption characteristic for converting radiant energy into heat for heating cutting edge 17 and also serves as an infrared radiation source whose radiation is a measure of its temperature. The illuminating 41a, 43a,etc. and detecting 41b, 43b, etc. fibers going to and coming from short segments of absorbing layer lOa, .
:, , . ~ .. , ~
~g~&16~72 lOb, lOc, etc. can be gathered into two separate bundles for each segment. ~y utilizing a separate radiant source 47, 49, 51, etcO to illuminate the radiakion absorbing material of each segment lOa, lOb, lOc, etc. and a separate detector for each source associated with each return fiber 41a, 41b, 41c, etc., the temperature of each segment can be independently monitoxed and the power output of the corresponding radiant source can be independently regulated so that the temperature of each segment along the cutting edge 17 can be maintained within a suitably constant temperature range, independent of the other segments along the cutting edge. Utilizing this principle, a rapidly-responding radiant source and detector may be time-shared among several segments along the length of the cutting edge 17.
Further, a plurality of individual filaments of the type pre-viously described with reference to Figures 1 and 2 may be lineally positioned along the length of the cutting edge 17 in order to independently elevate and regulate the temperature of a corresponding segment, independently of the temperature of an adjacent segment.
.
~ADIANT HEATING OF ITS CUT~ING EDGE
AND_METHOD OF USING THE SAME
Back~round of the Invention The control o~ bleeding during surgery accounts for a major portion of the total time involved in an operation. The :
bleeding that occurs from the plethora of small blood vessels that pervade all tissues whenever tissues are incised obscures the surgeon's vision, reduces his precision, and often dictates slow and elaborate procedures in surgical opera~ions. It is well known to heat the tissues to minimize bleeding from in-cisions, and surgical scalpels which are designed to elevate ~:
tissue temperatures and minimize bleeding are also well known.
One such scalpel transmits high frequency, high energy sparks from a small electrode held in the surgeon's hand to the tissues, where they are converted to heat. Typically, substantial ., ~'~ .
3L7;2 electrical currents pass throuyh -the patient's body to a lar~e electrode beneath the pa-tient, which completes the electrical circuit. Discharge of sparks and temperature conversion in the tissue are poorly controlled in distribution and intensity, and erratic muscular contractions in the patient are produced so that this apparatus cannot be us~d to perform precise surgery.
Further, apparatus of this type frequently produce severe tissue damage and debris in the form of charred and dead tissue, which materially interfere with wound healing.
Another well-known surgical scalpel employs a blade with a resistive heating element which cuts the tissue and pro-vides simultaneous hemostasis. Although these resistive elements can be readily brought to a suitably high and constant temper-ature iTI air prior to contacting tissues, as soon as portions of the blade~come in contact with tissues, they are rapidly cooled.
During surgery, non-predictable and continuously varying portions ~ -: -:
of the blade contact the tissues as they are being cut. As the blade cools, the tissue cutting and hemostasis become markedly less effective and tissue tends to adhere to the blade. If additional power is applied by conventional means to counteract this cooling, this additional power is selectively delivered to the uncooled portions of the blade r frequently resulting in excessive temperatures which may result in tissue damage and blade destruction. This results from the fact that in certain ;
known resistively heated scalpels, the heating is a function of the current s~uared times the resistance (I2~). In conventional metallic blades of this type, the higher the temperature of any -blade portion, the greater its electrical resistance, and con-sequently the greater the incremental heating resulting from incremental power input. ' -~
It is generally recognized that to seal -tissues and effect hemostasis it is desirable to operate at a temperature between 300C. and 1000C. ~nd for reasons noted above, it is desirable that electrothermal hemostatic surgical cutting instruments include a mechanism by which power is selectively delivered to those portions of the cutting edge that are cool-ed by tissue contact so that the blade may be maintained at a substantially uniform operating temperature within the desired optimal range. Recently, hemostatic scalpels have been des-cribed (see, for example, V. S. Patents 3,768,482 and 3,826,263) in which the temperature-controlling mechanisms include resistive heating elements disposed on the surface of the scalpel blade. However, such instruments require pre-cision in fabricating the dimensions of the heating elements to obtain the desired resistances. And such resistive heat-ing elements may be subjected to variations in resistance during use, as tissue juices and proteins become deposited upon ~le surface of the blade.
_ mmary of the In~ention In accordance with one aspect of this invention there is provided a blade comprising: cutting means includ-ing a cutting edge, said cutting means being substantially transparent to radiant energy applied through said cutting means to said cutting edge; and a radiant-energy absorptive means disposed in the region of said cutting edge.
In accordance with another aspect of this invention there is provided the method of heating the cutting edge of a blade means operating at an elevated temperature, the method comprising: introducing radiant energy into a~sub stantially transparent blade means; and absorbing radiant energy in the region of the cutting edge.
~ -3-. . ~
By way oE ~dded explanation, -tlle present inven~ion provides ~ sur~ical cutting instrument in which the cutting portion of the blade is brought to an elevated temperature by radiant heating of the internal struc-tures of the blade~
Radiant energy from a source such as a high temperature fila ment or ribbon or a laser is optlcally coupled to a substantial-ly transparent blade-shaped structure, one edge of which has been sharpened to form the cutting edge of the instrument.
A non-transmitting internally-re~lecting surface prevents loss Of radiant energy from within the blade. The resultant scattering of light by internal reflections tends to distribute radiant energy throughout the blade, and the optical scattering ~ ;
may be further enhanced by the incorporation of particulate scattering elements within the blade material.
.
,. . .
. .
, ~ -3a- ~
' .
. . , .. .... . ..... : ~ :
- . : , ~ ,.
3L7;~
Beneath the internally-re~lectin~ coating and c)nly alony the cutting edge o~ the blade, there is disposed a radiation-absorbing material which absorbs and converts the radiant energy to heat which is conducted through the material to the cutting edge to bring it to operating temperatures. The average temper-ature along the cutting edge may be adjusted by adjusting the power supplied by the radiation source, for example, by adjusting the electrical signals applied thereto.
Sel~ctive heating of those portions of the cutting edge that are cooled by tissue contact in order to maintain cutting temperatures sufficiently constant (i.e., temperature self-regulation) may be accomplished by fabricating the radiation absorber in the region of the cutting edge of a material which substantially increases in absorption coefficient with decreasing temperature within the operating temperature range. Since each local region of the material absorbs the distributed radiation in accordance with its local absorption coefficient, each local region may have its temperature regulated independently of the operating temperature of adjacent regions. Thus, even in the presence of unpredictable and substantial variations in the , cooling of the various regions of the heated edge resulting from the edge being manipulated to cut tissues, all regions along the ;
length of the cutting edge can be maintained within a suitably constant temperature range. Knvwn thermochromic materials which , have absorption coefficients that vary as a function of temper-I ature may be used as the radiation-absorbing material in the surgical instrument of the present invention.
De_cription of the Drawings Figure 1 is a partial side view of a surgical cutting instrument according to one embodiment of the present invention;
: ' Figure 2 is an end view of the apparatus o~ Figure 1 showing the blade-like element and the radiation source therein;
Figure 3 is a partial side view of an alternative embodiment of the present invention;
Figure 4 is an end view of the apparatus of Figure 3 .~ showing the optical channels therein for distributing radiation from a remote source; and . :
Figure 5 is a partial side view of another embodiment :~ which employs segmented thermochromic regions. `:
:: 10 Description of the Preferred Embodiment . Referring now to Figure 1, there is shown a partial ~
side view of a surgical cutting instrument which has a blade- ::
:` like element 9 that is suita~ly attached to handle 11. A high-intensity light or radiation source within the handle 11 in-~ cludes a lineally-mounted incandescent filament or ribbon 13 ;~ that is disposed within a parabolic reflector 15 which is oriented .' to direct the radiant energy ~rom the filament toward the cutting ~`, edge 17 and facets 16 at the lower portion 18 of the blade. The lineally-mounted filament 13 assures adequate distribution of the radiant energy therefrom substantially over the length of the cutting edge 17 of blade 9. The electrical power to heat the filament 13 is applied thereto by A.C. or D.C. source 20 via conductors 21 and 22. A photodetector 30 is optically coupled to the internal structure of the blade 9 and is electrically ~ :
coupled to the power source 20 through a conventional servo-regulator means 31 in a manner which controls the average power applied to the filament 13 in response to the level of radiant flux detected by photodetector 30.
Referring now to Figure 2, there is shown a cross ;~-~
section of the apparatus of Figure 1 inLLuding the filament 13 L7;i~
and the reflector 15 that directs radiant flux 5 substantially toward the facets 16 and cutting edge 17 of the balde 9. The filament 13, parabolic reElector 15 and radiation~transmitting window 14 may be formed into a chamber which is evacuated or filled with inert gas to minimize oxidation of the incandescent filament 13. The material of blade 9 should transmit and scatter well the radiant energy at the wavelengths of flux 5 from fila-ment 13 but should absorb poorly or not at all at these wave-lengths. A reflective optical coating 8 is disposed over the parabolic reflector and over the internal surfaces of the blade ; side walls 6 and 7 and the facets 16 of blade 9, but not over the window 14 through which the flux from the filament 13 is coupled to the blade 9. A layer 10 of radiation-absorbing, thermo-chromic material is disposed at the facets 16 of blade 9 adjacent the reflective coating 8 and acts as a collector of the radiant ; flux 5 from filament 13. The radiant flux 5 collected in layer ;~
10 is converted to heat which is conducted to the cutting edge 17.
Thermochromi¢ materials which havP absorption coefficients that vary as a function of temperature may be used as the radiation-absorbing material of layer 10. Materials which exhibit thermochromic properties in selected temperature ranges include indium antimonide, gallium antimonide, and other semiconductors, zinc oxide, some lead salts, and other inorganic and organic materials.
Only a portion of the radiation which illuminates the absorbing material of layer 10 is absorbed. ~he remaining non-absorbed portion of the radiation is transmitted through the layer 10 and i5 internally reflected by the reflective coating 8 back through the layer 10 (where further absorption occurs) and 3Q re-emerges in the relatively transparent region 9 of the blade :~:
?. . ,.",.,~ "
6~2 which is remote from the cutting edge where it follows a multi-reflective distribution path. As the temperature of the absorbing material 10 and hence oE the cutting edge 17 increases, absorption by the material of layer 10 decreases and the average radiant flux in the transparent region ~ of the blade increases.
Conversely, as the heated regions o~ the cutting edge 17 cool upon contact with tissue heing cut, radiation absorption by the material of layer 10 increases and the average radiant flux in the transparent region 9 of the blade decreases. ~he radiant-energy detector 30 may be coupled to the interior of the bladefor monitoring the average radiant flux within the blade to in-crease or decrease the power supplied by the source 20 to the radiation source 13 as required.
Absorption by layer 10 of the wavelengths of radiant energy produced by filament 13 thus experiences increments for temperature decrements within the operating range of the cutting edge, from 300C. to 1000C. It is this radiation absorption - property of the material of layer 10 that provides the self-regulating means by which local regions of the cutting edge 17 that cool upon contact with tissue being cut are radiantly heated by increased absorption of radiation. Other local regions of the cutting edge not cooled upon contact with tissue being cut do not exhibit increased absorption and therefore do not substantially change in their conversion of radiant energy to heat. Thus, as the temperature varies in various regions of facets 16 and the layer 10 disposed thereon, the radiation absorption of these re-gions varies inversely to assure increased radiation absorption of the cooled regions sufficient to maintain the operating 29 temperature thereof within the desired operating range.
z ~ s the layer lO and cutting edge 17 heat up prior to cutting, the layer lO becomes less absorptive and higher levels of radiant flux 5 are reflected from layer lO or are transmitted through layer lO to be internally reflected by the reflecting surface 8. This increases the light flux within the relatively transparent material such as glass or quartz, or th~ like, of blade 9. Radiation scattering centers such as rutile fibers, ~uartz particles, or the like, may be dispersed through the region 9 o~ the blade. The increased light flux in region 9 is detected by detector 30 which is coupled through a conventional .. ~
servo-regulator 31 to the power source 20 to decrease the power ~:
` supplied to ~ilament 13. The temperature of layer 10 and cutting edge 17 and facets 16 is thus stabilized within a preselected operating range. Conversely, as portions of the cutting edge 17 and facets 16 are cooled upon contact with tissue being cut, the material of layer lO in the locally-cooled regions increases the absorption of radiant flux and decreases the level of flux in the portion of blade 9 sensed by detector 30, and this acts through servo-regulator 31 to increase the power supplied by power source 20 to the filament 13. Where it is desirable to .:
maintain a relatively uniform wavelength spectrum of radiant energy over the dynamic range of power dissipation of the cutting instrument, the amount of surface area of the filament 13 heated to a specified temperature may be varied, as by retracting into the handle, or rotating within an aperture to vary the amount of radiant flux, rather than varying the temperature of the filament operating with a fixed, exposed area.
Alternatively, a relatively fixed spectrum can be accomplished by utili2ing a filter between w~ndow 14 and the blade.
Such a filter may also be used to narrow the bandwidth of the ..
.: '. :
radiant energy, and there~y simplify the selection of absorbing materials used in layer 10 or, the ilament 13 may he replaced by the ionized gas column of a gas discharge tube which emits radiant energy within one or a few characteristically narrow spectral lines) and which thus also simplifies the selection of absorbing materials used in layer 10.
Referring now to Figures 3 and 4, there are shown side and end views, respectively, of an alternative embodi~ment of the present invention in which the radiant source is disposed re-motely from the cutting instrument. Light pipe elements such as fiber optic filaments 33 are aligned in a linear array to irradiate the absorbing layer 10. A photodetector 30 may be disposed within the handle 11 to detect the level of radiant flux and to produce a control signal on line 35 in response thereto for controlling the power output from the remote source 37, such as a laser. Alternatively, selected fibers in the array 33 can be used to sample radiant flux at locations along the length of the blade and illuminate a remote photodetector, thereby to produce the requisite power~controlling signal ~lso, other optical means such as reflective mirrors and lenses .
may be used instead of the optical fibers to couple the radiant energy from the remote source into the absorbing layer 10.
Figure 5 illustrates still another embodiment of the present invention in which the material of the absorbing layers lOa, lOb, lOc, etc. e~hibits relatively constant absorption characteristic for converting radiant energy into heat for heating cutting edge 17 and also serves as an infrared radiation source whose radiation is a measure of its temperature. The illuminating 41a, 43a,etc. and detecting 41b, 43b, etc. fibers going to and coming from short segments of absorbing layer lOa, .
:, , . ~ .. , ~
~g~&16~72 lOb, lOc, etc. can be gathered into two separate bundles for each segment. ~y utilizing a separate radiant source 47, 49, 51, etcO to illuminate the radiakion absorbing material of each segment lOa, lOb, lOc, etc. and a separate detector for each source associated with each return fiber 41a, 41b, 41c, etc., the temperature of each segment can be independently monitoxed and the power output of the corresponding radiant source can be independently regulated so that the temperature of each segment along the cutting edge 17 can be maintained within a suitably constant temperature range, independent of the other segments along the cutting edge. Utilizing this principle, a rapidly-responding radiant source and detector may be time-shared among several segments along the length of the cutting edge 17.
Further, a plurality of individual filaments of the type pre-viously described with reference to Figures 1 and 2 may be lineally positioned along the length of the cutting edge 17 in order to independently elevate and regulate the temperature of a corresponding segment, independently of the temperature of an adjacent segment.
.
Claims (18)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A blade comprising:
cutting means including a cutting edge, said cutting means being substantially transparent to radiant energy applied through said cutting means to said cutting edge; and a radiant-energy absorptive means disposed in the region of said cutting edge.
cutting means including a cutting edge, said cutting means being substantially transparent to radiant energy applied through said cutting means to said cutting edge; and a radiant-energy absorptive means disposed in the region of said cutting edge.
2. A blade comprising:
cutting means including a tissue-cutting edge, said cutting means being substantially transparent to radiant energy applied through said cutting means to said tissue-cutting edge;
and a radiant-energy absorptive means which is character-ized by an absorption which varies in response to temperature over a predetermined temperature range, said radiant-energy absorptive means being disposed in the region of said cutting edge.
cutting means including a tissue-cutting edge, said cutting means being substantially transparent to radiant energy applied through said cutting means to said tissue-cutting edge;
and a radiant-energy absorptive means which is character-ized by an absorption which varies in response to temperature over a predetermined temperature range, said radiant-energy absorptive means being disposed in the region of said cutting edge.
3. The hemostatic cutting blade claimed in claim 2 wherein said blade is further defined as having radiant-energy scattering means disposed therein.
4. A hemostatic cutting blade as in claim 1 comprising radiant-energy reflective means disposed on surfaces of the blade to contain radiant energy therein.
5. A hemostatic cutting blade as in claim 1 wherein the radiant-energy absorptive means exhibits increased reflec-tance for increased temperature over a portion of the temperature range between approximately 300°C and 1000°C.
6. A hemostatic cutting blade as in claim 1 wherein the radiant-energy absorptive means exhibits increased trans-mission of radiant energy for increased temperature over a portion of the temperature range between approximately 300°C
and 1000°C.
and 1000°C.
7. a hemostatic cutting blade as in claim 1 compris-ing optical fibers for introducing radiant energy into said blade means.
8. A blade as in claim 1 comprising source means of radiant energy disposed to irradiate the radiant-energy absorp-tive means.
9. A blade as in claim 1 wherein said radiant-energy absorptive means exhibits increased absorption in response to a decrease in temperature over a portion of the temperature range between approximately 300°C and 1000°C.
10. A blade as in claim 8 wherein said source means of radiant energy includes an incandescent filament substantially lineally mounted along a portion of the length of the blade means.
11. A blade as in claim 8 comprising a reflector means coupling radiant energy from the source means toward the radiant-energy absorptive means disposed in the region of said cutting edge.
12. A blade as in claim 8 wherein said source means includes a gas-discharge source.
13. A blade as in claim 8 comprising:
photoresponsive means disposed to produce a control signal in response to the level of radiant energy within the blade means; and means coupled to said photoresponsive means and to said source means of radiant energy for altering the level of radiant energy produced thereby.
photoresponsive means disposed to produce a control signal in response to the level of radiant energy within the blade means; and means coupled to said photoresponsive means and to said source means of radiant energy for altering the level of radiant energy produced thereby.
14. A blade as in claim 1 comprising radiant-energy scattering means disposed within the blade means for dispersing therewith radiant energy.
15. A blade as in claim 12 wherein said gas-discharge source includes a laser.
16. The blade as in claim 8 wherein the temperature in the region of the cutting edge is elevated in response to radiant energy applied thereto.
17. The method of heating the cutting edge of a blade means operating at an elevated temperature, the method com-prising:
introducing radiant energy into a substantially transparent blade means; and absorbing radiant energy in the region of the cutting edge.
introducing radiant energy into a substantially transparent blade means; and absorbing radiant energy in the region of the cutting edge.
18. A method of heating as in claim 17 wherein increased amounts of radiant energy are selectively absorb-ed in regions of the cutting edge that are cooled.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/558,338 US4209017A (en) | 1970-08-13 | 1975-03-14 | Surgical instrument having self-regulating radiant heating of its cutting edge and method of using the same |
| US558,338 | 1975-03-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1086172A true CA1086172A (en) | 1980-09-23 |
Family
ID=24229161
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA246,549A Expired CA1086172A (en) | 1975-03-14 | 1976-02-25 | Surgical instrument having self-regulating radiant heating of its cutting edge and method of using the same |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS51122985A (en) |
| CA (1) | CA1086172A (en) |
| DE (1) | DE2609336C3 (en) |
| FR (1) | FR2303516A1 (en) |
| GB (1) | GB1546625A (en) |
Families Citing this family (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2717421C2 (en) * | 1974-05-21 | 1987-05-07 | Nath, Guenther, Dr., 8022 Gruenwald | Coagulator |
| DE2760397C2 (en) * | 1977-04-20 | 1989-04-27 | Guenther Dr. 8000 Muenchen De Nath | |
| US4736743A (en) * | 1986-05-12 | 1988-04-12 | Surgical Laser Technology, Inc. | Vaporization contact laser probe |
| FI82370C (en) * | 1987-12-30 | 1991-03-11 | Lasermatic Oy | Operation head for a laser device |
| AU4158489A (en) * | 1988-09-23 | 1990-03-29 | Trimedyne Laser Systems, Inc. | Heated catheter with thermal barrier |
| US6110167A (en) * | 1990-10-31 | 2000-08-29 | Premier Laser Systems, Inc. | Contact tip for laser surgery |
| US8182473B2 (en) | 1999-01-08 | 2012-05-22 | Palomar Medical Technologies | Cooling system for a photocosmetic device |
| US6517532B1 (en) | 1997-05-15 | 2003-02-11 | Palomar Medical Technologies, Inc. | Light energy delivery head |
| US6273884B1 (en) | 1997-05-15 | 2001-08-14 | Palomar Medical Technologies, Inc. | Method and apparatus for dermatology treatment |
| AU3450799A (en) | 1998-03-12 | 1999-09-27 | Palomar Medical Technologies, Inc. | System for electromagnetic radiation of the skin |
| US7354448B2 (en) | 2001-11-29 | 2008-04-08 | Palomar Medical Technologies, Inc. | Dental phototherapy methods and compositions |
| US20040147984A1 (en) * | 2001-11-29 | 2004-07-29 | Palomar Medical Technologies, Inc. | Methods and apparatus for delivering low power optical treatments |
| AU2003245573A1 (en) | 2002-06-19 | 2004-01-06 | Palomar Medical Technologies, Inc. | Method and apparatus for treatment of cutaneous and subcutaneous conditions |
| CN1708261B (en) | 2002-10-23 | 2012-07-04 | 帕洛玛医疗技术公司 | Phototreatment device for use with coolants and topical substances |
| EP1671162B1 (en) * | 2003-10-09 | 2014-01-01 | Kilolambda Technologies Ltd. | Optical hot tip |
| US7856985B2 (en) | 2005-04-22 | 2010-12-28 | Cynosure, Inc. | Method of treatment body tissue using a non-uniform laser beam |
| WO2007035444A2 (en) | 2005-09-15 | 2007-03-29 | Palomar Medical Technologies, Inc. | Skin optical characterization device |
| JP4928856B2 (en) * | 2006-07-11 | 2012-05-09 | 東京医研株式会社 | Surgical device |
| US7586957B2 (en) | 2006-08-02 | 2009-09-08 | Cynosure, Inc | Picosecond laser apparatus and methods for its operation and use |
| US9919168B2 (en) | 2009-07-23 | 2018-03-20 | Palomar Medical Technologies, Inc. | Method for improvement of cellulite appearance |
| WO2013158299A1 (en) | 2012-04-18 | 2013-10-24 | Cynosure, Inc. | Picosecond laser apparatus and methods for treating target tissues with same |
| US10285757B2 (en) | 2013-03-15 | 2019-05-14 | Cynosure, Llc | Picosecond optical radiation systems and methods of use |
| AU2019225242B2 (en) | 2018-02-26 | 2023-08-10 | Cynosure, Llc | Q-switched cavity dumped sub-nanosecond laser |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3826263A (en) * | 1970-08-13 | 1974-07-30 | R Shaw | Electrically heated surgical cutting instrument |
| US3768482A (en) * | 1972-10-10 | 1973-10-30 | R Shaw | Surgical cutting instrument having electrically heated cutting edge |
| IL40544A (en) * | 1972-10-11 | 1975-12-31 | Laser Ind Ltd | Laser device particularly useful as surgical instrument |
-
1976
- 1976-02-25 CA CA246,549A patent/CA1086172A/en not_active Expired
- 1976-02-26 GB GB769676A patent/GB1546625A/en not_active Expired
- 1976-03-06 DE DE19762609336 patent/DE2609336C3/en not_active Expired
- 1976-03-12 FR FR7607175A patent/FR2303516A1/en active Granted
- 1976-03-12 JP JP51027025A patent/JPS51122985A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| FR2303516B3 (en) | 1980-07-18 |
| DE2609336B2 (en) | 1978-11-30 |
| DE2609336C3 (en) | 1979-07-26 |
| JPS51122985A (en) | 1976-10-27 |
| GB1546625A (en) | 1979-05-23 |
| FR2303516A1 (en) | 1976-10-08 |
| DE2609336A1 (en) | 1976-09-30 |
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