WO1996013689A1

WO1996013689A1 - Illumination assembly and a method of operating an illumination assembly

Info

Publication number: WO1996013689A1
Application number: PCT/US1995/013899
Authority: WO
Inventors: Edsel G. Crenshaw; David C. Downey; Brian Peterson; Kevin B. Sinnett
Original assignee: Chiron Vision Corporation
Priority date: 1994-10-28
Filing date: 1995-10-27
Publication date: 1996-05-09
Also published as: AU3969795A

Abstract

An illumination assembly and a method of operating an illumination assembly. The assembly comprises first and second light sources (12, 14), and optical coupler (16), and controller (20). Each of the first and second light sources has an activated state for generating light, and an off state. The optical coupler is provided to connect the assembly to a fiber optic cable, which may then be used to transmit that light to a location remote from the illumination assembly. In operation, the controller activates the first light source to generate light and to transmit light to the optical coupler. The controller also monitors the first light source and in case the first light source ceases to operate in a predetermined manner, the controller automatically activates the second light source to generate light and to transmit light to the optical coupler.

Description

ILLUMINATION ASSEMBLY AMD A 1 METHOD OF OPERATING AN ILLUMINATION ASSEMBLY BACKGROUND OF THE INVENTION

This application is a continuation of copending application serial no. 08/330,922, filed October 28, 5 1994.

This invention generally relates to apparatus and methods for illuminating a surgical procedure, and more specifically, to apparatus and methods that are particularly well suited for providing illumination during microsurgery such as micro ophthalmic surgery. Microsurgical procedures are gaining ever- increasing acceptance in the surgical community for preforming precise, minimum invasive surgery for various parts of the body, and one particularly widespread microsurgical application is in the field of ophthalmology. In this application, commonly, a hand piece having a small tool is used either to cut or to mascerate the eye tissue while an irrigation or infusion liquid is brought to the surgery site. The cut or mascerated tissue is carried away from the surgical site by a suction conduit or tube to a collection vessel such as a bag or bottle. The surgical site may be illuminated by light conducted to that site through an optical fiber. Consoles are specifically designed for these ophthalmic procedures. These consoles are used to operate the tools and the suction and infusion lines used in the procedures, and to generate the light that is used to illuminate the surgical site. Typically, these consoles have a modular design and include a multitude of separable or removable modules, with each module being used to operate or to perform a specific task. For example, one module may be employed to operate the hand piece used to cut or mascerate the eye x- tissue, another module may^' be used to infuse and aspirate the surgical site, and a third module may be used to illuminate that site.

In one prior art console, the illuminating module includes a pair of light bulbs, a primary bulb and a 0 back up bulb. The module also includes a plurality of light conditioning means, such as one or more lenses and one or more filters, to conditio-.ι the light generated in the module. In use, the primary bulb is activated and aligned with the light conditioning means; and light _t- from this bulb is transmitted through the conditioning means and into the optical fiber, which then transmits the light to the surgical site. In case the primary bulb burns out, an operator moves the back-up bulb into alignment with the light conditioning means, and this ₀ back-up bulb is activated to provide light to the surgical site. This procedure is highly effective and reliable. It is believed, however, that the procedure could be further improved by eliminating the need for an operator to move the back-up bulb into the desired - position in the module to transmit light to the surgical site.

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SUMMARY OF THE INVENTION

An object of this invention is to improve methods c and apparatus for illuminating microsurgical procedures.

Another object of the present invention is to monitor continuously a light bulb used to illuminate a microsurgical procedure, and to switch automatically to a back-up light bulb in case the former light bulb burns out.

A further object of this invention is to provide an apparatus for illuminating microsurgical procedures with a processor to control automatically various aspects of the apparatus. Another object of the present invention is to automatically activate a back-up light bulb and to automatically move that bulb into position to illuminate a microsurgical procedure, in case a primary light bulb burns out during the procedure.

These and other objectives are attained with an illumination assembly comprising first and second light sources, an optical coupler and control means. Each of the first and second light sources has an activated or on state for generating light, and an off state. The optical coupler is provided to connect the assembly to a fiber optic cable and to transmit light from the light sources to that fiber optic cable, which may then be used to transmit that light to a location remote from the illumination assembly.

In operation, the control means activates the first light source to generate light and to transmit light to the optical coupler. The control means also monitors that first light source and, in case the first light source ceases to operate in a predetermined manner, the control means automatically actuates the c second light source to ge'nerate light and to transmit light to the optical coupler. Preferably, the control means includes a photosensor that generates a signal representing the intensity of light generated by the first light source, and this signal is terminated in

10 case the first light source stops generating light. If this signal is terminated when the first light source is activated, then the control means activates the second light source to generate light.

Further benefits and advantages of the invention

15 will become apparent from a consideration of the following detailed description given with reference to the accompanying drawings, which specify and show preferred embodiments of the invention.

20 BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a top schematic view of an illumination assembly embodying the present invention. Figure 2 is a view similar to the view of Figure _c- 1, but with two light bulbs of the illumination assembly in an alternate position.

Figure 3 is a side view of a portion of the illumination assembly.

Figure 4 is a schematic drawing of a control -₀ circuit of the illumination assembly.

35 2 Figure 5 illustrates a testing circuit that may be used in the illumination assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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Figures 1-4 illustrate illumination assembly 10 generally comprising first light source 12, second light source 14, optical coupler 16 and control means 20; and control means 20, in turn, includes sensing means 22 and

10 first and second activating means 24 and 26.

Preferably, assembly further includes support subassembly 30; and this subassembly includes platform

32, platform support means 34 and drive means 36. More specifically, platform support means 34 includes a pair

2 of rails, and drive means 36 includes motor 40 and connecting means 42.

In addition, preferably control means 20 further includes signal generating means 44, third activating means 46, and first and second testing means 50 and 52.

20 Moreover, control means 20 preferably includes first and second processors 54 and 56; and first, second and third activating means 24, 26 and 46 and signal generating means 44 are part of processor 54. Figure 1 also illustrates reflector 60, lenses 62 and 64, infra-red _pc- filter 66, iris 70, fan 72, fan motor 74, thermal sensor 76 and fan activating means 80, which preferably is also part of processor 54.

Generally, each of the first and second light sources 12 and 14 has an activated or on state for

-- generating light, and a deactivated or off state.

Coupler 16 is provided to connect assembly 10 to a fiber

35 2 optic cable (not shown) and to transmit light from light sources 12 and 14 to that fiber optic cable, which may then be used to transmit that light to a location remote from assembly 10. Control means 20 activates first _t- light source 12 to generate light and to transmit light to coupler 16. Control means 20 also monitors that first light source 12, and, in case the first light source ceases to operate in a predetermined manner, the control means automatically activates second light

20 source 14 to generate light and to transmit light to coupler 16.

More specifically, first activating means 24 of control means 20 is provided to activate first light source 12 to transmit light to coupler 16. Sensing r r- means 22 is provided to generate a variable signal representing operation of first light source 12; and second activating means 26 of control means 20 acts, in response to a predetermined change in the signal from sensing means 22, to activate second light source 14 to ₀ generate light and to transmit that light to coupler 16.

Preferably, sensing means 22 monitors and generates a signal representing the intensity of light generated by first light source 12. This signal is terminated in case first light source 12 stops r,,- generating light; and second activating means 26 acts, r- in response to termination of the signal from sensing means 22, to activate second light source 14 to generate light and to transmit light to coupler 16. It should be noted that second light source 14 may be activated for

_₀ other reasons or factors relating to the operation of first light source 12; and, for example, light source 14

35 2 may be activated when the light generated by first light source 12 falls below a given level.

With the preferred embodiment of assembly 10, sensing means 22 is a photo sensor that generates an electric current representing the intensity of light generated by light source 12. This current is transmitted to control means 20, specifically to signal generating means 44 of processor 54. In case light source 12 stops generating light, the electric signal 0 from sensing means 22 also terminates. When first light source 12 is in the on state but the signal from sensing means 22 sensor is terminated, signal generating means 44 generates its own signal. This signal from generating means 44 is transmitted to second activating -r means 26, which in turn generates a signal and uses that signal to activate light source 14 to generate light and to transmit that light to coupler 16.

With the embodiment of assembly 10 illustrated in the drawings, each light source 12 and 14 is in or is o moved into a preferred operating position when the light source is activated. Figure 1 shows light source 12 in the operating position, and Figure 2 show light source 14 in the operating position. Support subassembly 30 is provided to move light sources 12 and 14 into and out of _c their preferred operating positions.

More specifically, first and second light sources 12 and 14 are mounted on platform 32 of support subassembly 30, and this platform is supported by support means for movement between first and second ₀ positions, shown in Figures 1 and 2 respectively. In the first position of platform 32, light source 12 is in

5 2 the operating position; and in the second position of platform 32, light source 14 is in the operating position. Drive means 36 is connected to platform 32 to move the platform between those first and second c positions and, in this way, to move light sources 12 and 14 into and out of the operating position.

With particular reference to Figures 1-3, preferably, platform 32 of support subassembly 30 is supported by rails 34 for sliding movement therealong, 0 and first and second light sources 12 and 14 are mounted on the platform for sliding movement therewith. Further, is connected to platform 32, via connecting means 42, to move the platform between its first and second positions. c Any suitable means 42 may be used to connect motor 40 to platform 32. Preferably, though, motor 40 and platform 32 are connected together via notched rack 82 and pinion 84. With particular reference to Figure 3, rack 82 is connected to and extends along platform 0 32, specifically an underside thereof. In addition, motor 40 includes rotatable motor shaft 86; and pinion 84 is mounted on motor shaft 86 for rotation therewith, and the pinion engages notched rack 84. In the operation of motor 40, motor shaft 86 rotates pinion 84, _c and rotation of the pinion slide rack 82 and platform 32 along rails 34.

Third activating means 46 of control means 20 is provided to actuate support subassembly 30 to move light source 14 into the operating position in assembly 10 in ₀ response to the above-mentioned predetermined change in the signal from sensing means 22. Preferably, third

5 activating means 46 generates an operating signal and transmits that signal to drive means 36 to operate that drive means to move platform 32 from its first position to its second position in response to this predetermined change in the signal from sensing means 32.

With the preferred embodiment of control means 20, the above-mentioned signal from generating means 44, which is generated when the signal from photo sensor 22 is terminated, is also transmitted to third activating means 46. When third activating means 46 receives this signal, activating means 46 transmits an operating signal to motor 40 to operate the motor to slide platform 32 along rails 34. Preferably, motor 40 is an electric motor, and the operating signal from activating means 46 is an electric signal.

Testing means 50 and 52 are is provided to test light sources 12 and 16 to determine if those light sources are burned out prior to activating the light sources. If this test shows that first light source 12 is burned out, then, instead of activating the first light source, second light source 14 is activated to generate light. If this test shows that both light sources 12 and 14 are burned out, then neither light source is activated, and control means 20 generates an error signal to advise an operator of this condition. Preferably, testing means 50 and 52 test light sources 12 and 14 by determining whether the filaments of those light sources are electrically conductive or non- conductive. Also, testing means 50 and 52 are preferably identical to each other, and Figure 5 illustrates testing means 50 in greater detail. 2 With reference to Figure 5, testing means 50 includes resistors 88 and 90, transistor 92 and DC power sources 94 and 96. Resistors 88 and 90 are located in series in line 100 between lamp filament 12a and ground. c The base of transistor 92 is connected to line, between resisters, and the emitter of transistor is connected to ground. The collector of transistor 92 is connected to power source 96, which may be, for example, a 5 volt DC power supply.

20 ^To test filament 12a, that filament is connected to power supply 96, which may be for example, a 24 volt DC power supply. If lamp filament 12a is intact, current flows through the lamp filament and resisters 88 and 90, activating transistor 92; and when this happens,

2_c the voltage level of the collector of transistor 92 drops to a low level. If lamp filament 12a is not intact, transistor 92 is not activated and the voltage level of the transistor collector remains high.

Thus, during this test, a high voltage level at

₂₀ the transistor collector indicates that lamp 12 is operable, and a low voltage level at that transistor collector indicates that the lamp is not operable. The voltage of the transistor collector, or a signal representing that voltage level, is applied to control

-,- means 20, specifically processor 56. A similar voltage or voltage signal from testing means 52 may be applied to processor 56 to indicate whether lamp 14 is operable.

Preferably, in the operation of assembly 10, processor 56 tests light sources 12 and 14, via testing means 50 and 52, prior to either of those light sources being activated. If first light source 12 is determined

35 2 to be operable, processor 56 transmits a signal to processor 54 to activate that light source; however, if first light source 12 is determined to be not operable, processor 56 transmits a signal to processor to activate z second light source 14. Processor 56 may also generate a plurality of signals to advise an operator of the status or conditions of light sources 12 and 14.

Assembly 10 may be used for a variety of purposes and in a variety of specific applications. For example, 0 assembly 10 may be used during ophthalmic surgery to generate light that is conducted to the surgical site. In this use of system 10, a fiber optic cable (not shown) is connected to optical coupler 16, and light from either light sources 12 or 14 is transmitted into c that fiber optic cable, which is then used to conduct the light to the surgical site.

In this operation of system 10, light source 12 is activated and gives off light in all directions. As in a common flash light or car head light, there is a 0 reflector 60 behind the light source that reflects the light in a forward direction. The reflected light strikes lens 62 that refracts bent light rays into straight light rays. These straight light rays then pass through an infra-red filter 66 which filters out _c infra-red radiation (the heat portion of the light), producing a light beam referred to as cool light. This cool light then passes through another lens 64 that narrows the light rays onto the fiber optic connector 16, and the light passes from the connector and through ₀ a fiber optic cable and illuminator (not shown) and into the eye.

5 2 In this operation of assembly 10, preferably an operator is able to adjust the intensity of light conducted into the fiber optic cable. For this purpose, an operator controlled signal generator 102 is used to c generate a variable signal and to transmit that signal to processor 56. Processor 56 then adjusts the intensity of the light transmitted into the fiber optic cable, in response to the signal received from signal generator 102. This may be done, for example, by

20 adjusting iris 70.

Heat may be generated in assembly 10, and fan 72 is provided to cool the system by directing ambient air over elements thereof. Fan 72 may be located behind light bulbs 12 and 14 to draw air over the elements in

-, ,- the path of the light beam passing into coupler 16; and fan 72 is connected to fan motor 74, which may be actuated to drive the fan. Preferably, fan motor 74 is controlled by processor 54, specifically fan activating means 80 thereof, and thermal sensor 76. ₀ Generally, fan 72 is activated when light source 12 is activated, and the fan continues to operate as long as either one of the light sources 12 or 14 is activated. Moreover, fan 72 continues to operate even after light sources 12 and 14 are both deactivated, p_c- until the temperature of the air adjacent sensor 76 falls below a given level. More specifically, when light source 12 is activated, fan activation means 80 generates a motor control signal that is conducted to fan motor 74 to operate that motor and drive fan 72. Processor 54 continues to transmit this motor control signal to motor 74, and fan 72 continues to operate, as

35 2 long as either one of light sources 12 and 14 is activated.

Even after light sources 12 and 14 are deactivated, processor 54 continues to transmit the c motor control signal to motor 74 and fan 72 continues to operate, until a signal from sensor 76 indicates that the temperature adjacent the sensor has fallen below the given level. When this occurs, processor 54 stops transmitting the motor control signal to motor 74, and

2o the fan motor and fan 72 are deactivated. Preferably thermal sensor 76 is or includes a conventional thermistor and generates an electric current representing the temperature of the air adjacent the sensor, and this current is conducted to activating

2-r means 80 of processor 54. As will be understood by those of ordinary skill in the art, processor 54 may be designed to activate fan motor 74 in accordance with other specific procedures based at least in part on the current from sensor 76.

2o The individual elements of system 10, including light sources 12 and 14, processors 54 and 56 and photo sensor 22, may be standard, conventional items. Preferably, both light sources 12 and 14 are high intensity light bulbs, and, for example, they may be 150

_2c watt light bulbs. Also, preferably both motors 40 and 74 are electric motors.

Assembly 10 is very well suited for use in a modular console that includes a multitude of other modules for operating other instruments or for

-,. preforming other tasks related to ophthalmic surgery. For example, assembly 10 may be used in the console

35 disclose_d in co-filed PCT application no. for which priori_ty is based on U.S. s/n 08/330,926 (Attorney docket PD-0395) the disclosure of which is herein incorporated by reference.

In such an application, processor 56 may be the console processor, while processor 54 may be the fiber optic module processor. The console processor, generally, controls the over-all operation of the console and acts as a communications interface between the console and the operator. Also, commands to activate the fiber optic module are generated by processor 56 and transmitted to module processor 54. Likewise, data transmitted to or generated by module processor 54 may be transmitted to console processor 56 to keep that processor, and the console operator, informed of that data.

While it is apparent that the invention herein disclosed is well calculated to fulfill the objects previously stated, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.

Claims

2 CLAIMS

1. An illumination assembly comprising: a first light source having an activated c state for generating light; a second light source having an activating state for generating light; an optical coupler to connect the assembly to a fiber optic cable and to transmit light from the first 20 ^an< second light sources to said fiber optic cable; and control means connected to the first and second light sources, to activate the first light source to generate light and to transmit light to the optical coupler, to monitor the first light source and to r _<~ activate automatically the second light source to generate light and to transmit light to the optic coupler in case the first light source ceases to operate in a predetermined manner, the control means including i) first activating means for activating the 2o first light source to generate light and transmit light into the optical coupler, ii) sensing means to generate a variable signal representing operation of the first light source, and _I- iii) second activating means, acting in response to a predetermined change in the signal from the sensing means, to activate the second light source to generate light and transmit light into the optical coupler. „- 2. An illumination assembly according to Claim 1, wherein:

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2 the sensing means includes a photo sensor sensing the intensity of light generated by the first light source; and the variable signal from the sensing means c includes an intensity signal representing the intensity of light generated by the first light source.

3. An illumination assembly according to Claim 2, wherein the second activating means activates the second light source when the intensity signal is

20 terminated

4. An illumination assembly according to Claim 2, wherein: the intensity signal has a magnitude; and the second activating means activates the 2_c second light source when the magnitude of the intensity signal falls below a given level.

5. An illumination assembly according to Claim 1, further comprising: a support subassembly supporting the first ₂₀ and second light sources for movement into and out of an operating position; and wherein the control means further includes third activating means to activate the support subassembly to move the second light source into the _pt- operating position in response to said predetermined change in the signal from the sensing means.

6. An illumination assembly according to Claim 5, wherein: the support subassembly includes _- i) a platform,

35 2 ii) means supporting the platform for movement between first and second positions, and iii) drive means connected to the platform to move the platform between said first and second positions; the first and second light sources are mounted on the platform for movement therewith; and the third activating means generates an operating signal and transmits the operating signal to 0 the drive means to operate the drive means to move the platform between said first and second positions in response to said predetermine change in the signal from the sensing means.

7. An illumination assembly according to Claim c 6, wherein: the means supporting the platform includes a pair of rails; the platform is supported by the rails for sliding movement therealong; o the drive means include i) a motor, and ii) means connecting the motor to the platform, wherein operation of the motor slides the platform along the rails; and _C- the third activating means transmits the operating signal to the motor to operate the motor to slide the platform along the rails in response to said predetermined change in the signal from the sensing means. 0

5 2 8. An illumination assembly according to Claim 1, wherein the control means further includes means to test the operability of the first light source.

9. An illumination assembly according to Claim

■ 8, wherein the first light source includes a filament, and the testing means includes means to determine if the filament is operable to generate light.

10. A method of operating an illumination assembly for illuminating a surgical site, the

20 illumination assembly having first and second light sources, each of the light sources having (i) and on state for generating light, and (ii) and off state, the method comprising the steps of: switching the first light source to the on state r _e- to generate light; conducting light from the first light source to the surgical site; monitoring the first light source and automatically switching the second light source to the 2o on state to generate light in case the first light source ceases to operate in a predetermined manner, including the steps of i) generating a variable signal representing operation of the first light source, p_c- ii) transmitting said variable signal to a controller, and iii) the controller, transmitting an actuation signal to the second light source to switch the second light source to the on state in response to a given _₀ change in the variable signal.

11. A method according to Claim 10, wherein:

35 2 the monitoring step includes the step of sensing the intensity of the light generated by the first light source; and the generating step includes the step of generating an intensity signal representing the intensity of the sensed light, and terminating the intensity signal when the first light source stops generating light; and the step of transmitting the actuation signal 20 to the second light source includes the step of transmitting the actuation signal to the second light source when the intensity signal is terminated.

12. A method according to Claim 10, wherein: the illumination assembly includes an

2c operating position for the light sources; and the step of automatically switching the second light source to the on state further includes the step of moving the second light source into the operating position in response to said given change in

2o the signal from the sensing means.

13. A method according to Claim 10, further including the steps of: checking the first light source prior to switching the first light source to the on state to _2c determine if the first light source is operable or not operable; and switching the second light source to the on state if the first light source is not operable.

14. A method according to Claim 13, wherein the -₀ checking step includes the step of also checking the second light source prior to switching the first light

35 O 96/13689 PCI7U S95/13899

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2 source to the on state to determine if the second light source is operable or not operable.

15. A method of operating an illumination assembly for illuminating a surgical site, the ill- emanation assembly including first and second light sources, each of the light sources having (i) an on state for generating light, and (ii) an off state, and the illumination assembly further including a support subassembly supporting each of the first and second 0 light sources for movement into and out of an operating position, the method comprising the steps of: switching the first light source to the on state to generate light; conducting light from the first light source, _c with the first light source in the operating position, to the surgical site; sensing the intensity of the light generated by the first light source; generating an intensity signal representing 0 the intensity of the light generated by the first light source; transmitting the intensity signal to a controller; the controller, generating first and second actuation signals in response to a given change in the 5 intensity signal; the controller transmitting the first actuation signal to the support subassembly to move the first light source out of the operating position and to move the second light source into the operating 0 position;

5 the controller transmitting the second actuation signal to the second light source to switch the second light source to the on state to generate light; c conducting light from the second light source to the surgical site.

16. A method according to Claim 15, wherein: the step of generating the intensity signal includes the step of terminating the intensity signal 0 when the first light source stops generating light; the step of generating the first and second actuation signals includes the step of generating the first and second actuation signals when the intensity signal is terminated. c 17. A method according to Claim 15, further including the steps of: checking the first light source prior to switching the first light source to the on state to determine if the first light source is operable or not 0 operable; and switching the second light source to the on state if the first light source is not operable.

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