CA2293094A1 - Fluorescence based optical switch - Google Patents
Fluorescence based optical switch Download PDFInfo
- Publication number
- CA2293094A1 CA2293094A1 CA 2293094 CA2293094A CA2293094A1 CA 2293094 A1 CA2293094 A1 CA 2293094A1 CA 2293094 CA2293094 CA 2293094 CA 2293094 A CA2293094 A CA 2293094A CA 2293094 A1 CA2293094 A1 CA 2293094A1
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- Prior art keywords
- light
- fluorescent
- optical
- optical fiber
- film
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Classifications
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
- H03K17/941—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated using an optical detector
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
- H03K2217/94—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated
- H03K2217/941—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated using an optical detector
- H03K2217/94102—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated using an optical detector characterised by the type of activation
- H03K2217/94108—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated using an optical detector characterised by the type of activation making use of reflection
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- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
Abstract
The invention relates to a fiber optic switch that utilizes a flexible fluorescent film assembly to emit fluorescence excited by incident light. The incident light is emitted from an optical fiber and the fluorescence is collected back into the optical fiber.
Description
FLOURESCENCE BASED OPTICAL SWITCH
FIELD
The invention relates to a fiber optic switch that utilizes a flexible fluorescent film assembly to emit fluorescence excited by incident light from the fiber and collected back into the fiber.
BACKGROUND OF THE INVENTION
The development of fiber optic switches has been in response to a need to avoid electrical power in the control lines of devices used in atmospheres with a risk of explosion and in the presence of liquid where fatal shock may result.
U.S. Pat. No. 3,999,074, issued to Callaghan, discloses the general arrangement of utilizing light transmission to produce a variable electrical output signal to control an electronic switch. The electronic switch, in turn, controls power to a load.
U.S. Pat. No. 4,045,667, issued to Hanson, discloses a single fiber optical control system utilizing a fiber optic bundle. The fiber optic bundle functions to carry light from a transceiver to an optical selector. The light in the optical receiver is reflected back down the fiber optic bundle to the transceiver where it impinges on one of several photo-detectors depending upon the switch position.
The photo-detectors distinguish the spectrum of colored light to generate multiple electronic control states.
U.S. Pat. No. 4,315,147, issued to Harmer, discloses a two-position switch having an active actuator. when the actuator is depressed, it intercepts light passing from one segment of an optical fiber to another. Conversely, when the actuator is on the extended position, it permits the transmission of light. The actuator must me inserted between the fiber segments thereby creating a gap between the fiber segments that light must traverse in going from one segment to the other.
U.S. Pat. No. 4,904,044, issued to Tamulevich, discloses a flexible filter oriented between two optical fibers. The filter serves to filter light passing from one optical fiber to the other. Again, the filter is spaced apart from each of the two fibers. Moreover, alignment of the two fibers is critical.
U.S. Pat. No. 4,704,656 issued to Neiger discloses a single fiber control system using a mirror to reflect light received from a fiber back into the fiber, when the mirror is in a reflecting position. Upon moving the mirror into a non-reflecting position, light from the fiber is not reflected back into the fiber. The mirror is attached to an actuator that swings it between reflecting and non-reflecting positions with respect to the fiber tip. The efficiency of the system is very sensitive to parallelism errors between the fiber face and mirror surface.
U.S. Pat. No. 5,892,862, issued to Kidder et al., describes a fiber optic switching system that includes an optical switch having a movable actuator and a light fiber coupled to the actuator. Light directed into the fiber contacts a flexible reflective film whose reflectivity is conditioned to provide at least two different reflective surfaces. The fiber in the actuator abuts or is placed in close proximity to the film throughout its movement from one position to another. A detector detects light reflected from the film. The actuator is movable so as to direct light from the light fiber from the one reflective surface of the film to another. The detector detects light reflected from the film so as to determine which reflective surface of the film the light has been reflected from.
U.S. Pat. No. 5,046,806, issued to Kidder et al., discloses a flexible filter attached to a carrier. The filters are positionable in front of a fiber by movement of a switch body. Again, a lens and a retro-reflector are used after the filter in order to focus and reflect the light back down the fiber.
FIELD
The invention relates to a fiber optic switch that utilizes a flexible fluorescent film assembly to emit fluorescence excited by incident light from the fiber and collected back into the fiber.
BACKGROUND OF THE INVENTION
The development of fiber optic switches has been in response to a need to avoid electrical power in the control lines of devices used in atmospheres with a risk of explosion and in the presence of liquid where fatal shock may result.
U.S. Pat. No. 3,999,074, issued to Callaghan, discloses the general arrangement of utilizing light transmission to produce a variable electrical output signal to control an electronic switch. The electronic switch, in turn, controls power to a load.
U.S. Pat. No. 4,045,667, issued to Hanson, discloses a single fiber optical control system utilizing a fiber optic bundle. The fiber optic bundle functions to carry light from a transceiver to an optical selector. The light in the optical receiver is reflected back down the fiber optic bundle to the transceiver where it impinges on one of several photo-detectors depending upon the switch position.
The photo-detectors distinguish the spectrum of colored light to generate multiple electronic control states.
U.S. Pat. No. 4,315,147, issued to Harmer, discloses a two-position switch having an active actuator. when the actuator is depressed, it intercepts light passing from one segment of an optical fiber to another. Conversely, when the actuator is on the extended position, it permits the transmission of light. The actuator must me inserted between the fiber segments thereby creating a gap between the fiber segments that light must traverse in going from one segment to the other.
U.S. Pat. No. 4,904,044, issued to Tamulevich, discloses a flexible filter oriented between two optical fibers. The filter serves to filter light passing from one optical fiber to the other. Again, the filter is spaced apart from each of the two fibers. Moreover, alignment of the two fibers is critical.
U.S. Pat. No. 4,704,656 issued to Neiger discloses a single fiber control system using a mirror to reflect light received from a fiber back into the fiber, when the mirror is in a reflecting position. Upon moving the mirror into a non-reflecting position, light from the fiber is not reflected back into the fiber. The mirror is attached to an actuator that swings it between reflecting and non-reflecting positions with respect to the fiber tip. The efficiency of the system is very sensitive to parallelism errors between the fiber face and mirror surface.
U.S. Pat. No. 5,892,862, issued to Kidder et al., describes a fiber optic switching system that includes an optical switch having a movable actuator and a light fiber coupled to the actuator. Light directed into the fiber contacts a flexible reflective film whose reflectivity is conditioned to provide at least two different reflective surfaces. The fiber in the actuator abuts or is placed in close proximity to the film throughout its movement from one position to another. A detector detects light reflected from the film. The actuator is movable so as to direct light from the light fiber from the one reflective surface of the film to another. The detector detects light reflected from the film so as to determine which reflective surface of the film the light has been reflected from.
U.S. Pat. No. 5,046,806, issued to Kidder et al., discloses a flexible filter attached to a carrier. The filters are positionable in front of a fiber by movement of a switch body. Again, a lens and a retro-reflector are used after the filter in order to focus and reflect the light back down the fiber.
In any mirror actuator, the coupling efficiency of the reflected light and, therefore, the effectiveness of the signal detection, are sensitive to alignment problems. The mirror actuator mechanism must orient the mirror surface parallel and in very close proximity to the fiber face in order to maintain good efficiency. In any system in which there is a gap between an end of the fiber and the mirror, the surfaces of the fiber and mirror will be prone to contamination. Both back scattering and contamination in such systems will cause loss of light and, hence reduced efficiency. Back scattering at any of the other optical interfaces can create additional noise in the optical signal and require additional signal processing or detector compensation to accurately detect the state of the switch.
One way to eliminate the effect of back-scattered light on detector performance is to utilize the principle of atomic or molecular fluorescence to create an optical switch.
The property of fluorescence is well known in the art.
Fluorescence is the result of activity at the atomic level and is the result of the interaction of the electrons of an elemental or molecular target, with incident electromagnetic energy, typically in the form of light. G,lhen a photon of a suitable energy level is absorbed by the target, it transfers its energy to the ground state electron, raising _~~~-, _.
it to one of the available energy levels. This higher energy level is usually an unstable physical state. As the electron tries to return to a more stable state it loses some of its energy in non-radiative processes. The electron then makes a transition to the ground state emitting a photon with less energy and therefore a longer wavelength of light than that of the absorbed photon. This shift in energy levels between illumination, or excitation light, and emitted light, is a characteristic property of a given compound and is known as the Stokes shift.
This property of fluorescence can be exploited with simple and low cost optics, filters and electronics to differentiate and decouple the higher energy, shorter wavelength impulse optical signal from the longer wavelength return optical signal and thus eliminate the problems associated with optical backscatter affecting reflectance based optical switches. The present invention provides these and other related advantages.
SUI~iARY OF THE INVENTION
The present invention provides methods and apparatus that permit the detection of the state of a switch by optically guiding excitation light through an optical fiber and illuminating a fluorescent target, or targets, in the switch assembly. The fluorescent light emitted from the target is collected into an optical fiber, and optically guiding into ~___~.___.... ____ ~ _.___ a detector assembly capable of measuring the relative intensity and wavelength of the induced fluorescence emission of the target. Actuation of the switch causes movement of the optical fiber relative to the targets, or of the targets relative to the optical fiber, and introduces different fluorescent targets with different relative intensity and wavelength of induced fluorescence emission into the optical path. By detecting these differences the apparatus determines the state of the switch and initiates the action that the switch controls.
The present invention may be used in conjunction with a variety of devices including, but not limited to, surgical pencils and controllers.
According to the invention there is provided a fiber optic switching system that includes an optical switch having a movable actuator and a light fiber means coupled to the actuator that terminates at an end surface thereof for conducting light from a light source to the optical switch mechanism. A flexible film, whose surface is conditioned to provide at least two different fluorescent surfaces, is positioned such that an end surface of the actuator abuts the film throughout its movement from one position to another. A detector means detects light emitted from the film and returned by the fiber means. The actuator is movable so as to direct light from the light fiber means to different fluorescent surfaces of the film. The detector means detects light emitted from the film so as to determine from which fluorescent surface of the film light has been emitted.
The film may have a fluorescent surface and a non-fluorescent surface.
Alternatively, the film may have multiple fluorescent surfaces that emit at different wavelength regions. In this case the detectors would have corresponding filters that would enable them to detect multiple switch states.
Alternatively, fluorescent targets with graduated strength of emission may be employed for use as continuously variable controllers.
A major advantage of the flexible film abutting the end of the actuator or fiber is the insensitivity of that arrangement to film misalignment. The flexible film conforms to the face of the fiber or actuator, thereby maintaining the parallelism between film and fiber surfaces that are necessary to achieve high coupling efficiency.
Further, by arranging the end of the fiber to abut the flexible film throughout its range of movement, contamination of the area between the fiber and film with fluids or air-borne particulate is greatly reduced.
The light fiber means may be a single optical fiber or a group of fibers providing a single optical path to and from the switching actuator.
A directional coupler may be coupled to the light fiber means to direct light returning from the optical switch mechanism to the detector means. The detector means may include a photo detector positioned to detect light emitted from the film.
Other objects and advantages of the invention will become clear from the following detailed description of the preferred embodiment, which is presented by way of illustration only and without limiting the scope of the invention to the details thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof, will be best understood by reference to the description which follows, read in conjunction with the accompanying drawings, wherein:
One way to eliminate the effect of back-scattered light on detector performance is to utilize the principle of atomic or molecular fluorescence to create an optical switch.
The property of fluorescence is well known in the art.
Fluorescence is the result of activity at the atomic level and is the result of the interaction of the electrons of an elemental or molecular target, with incident electromagnetic energy, typically in the form of light. G,lhen a photon of a suitable energy level is absorbed by the target, it transfers its energy to the ground state electron, raising _~~~-, _.
it to one of the available energy levels. This higher energy level is usually an unstable physical state. As the electron tries to return to a more stable state it loses some of its energy in non-radiative processes. The electron then makes a transition to the ground state emitting a photon with less energy and therefore a longer wavelength of light than that of the absorbed photon. This shift in energy levels between illumination, or excitation light, and emitted light, is a characteristic property of a given compound and is known as the Stokes shift.
This property of fluorescence can be exploited with simple and low cost optics, filters and electronics to differentiate and decouple the higher energy, shorter wavelength impulse optical signal from the longer wavelength return optical signal and thus eliminate the problems associated with optical backscatter affecting reflectance based optical switches. The present invention provides these and other related advantages.
SUI~iARY OF THE INVENTION
The present invention provides methods and apparatus that permit the detection of the state of a switch by optically guiding excitation light through an optical fiber and illuminating a fluorescent target, or targets, in the switch assembly. The fluorescent light emitted from the target is collected into an optical fiber, and optically guiding into ~___~.___.... ____ ~ _.___ a detector assembly capable of measuring the relative intensity and wavelength of the induced fluorescence emission of the target. Actuation of the switch causes movement of the optical fiber relative to the targets, or of the targets relative to the optical fiber, and introduces different fluorescent targets with different relative intensity and wavelength of induced fluorescence emission into the optical path. By detecting these differences the apparatus determines the state of the switch and initiates the action that the switch controls.
The present invention may be used in conjunction with a variety of devices including, but not limited to, surgical pencils and controllers.
According to the invention there is provided a fiber optic switching system that includes an optical switch having a movable actuator and a light fiber means coupled to the actuator that terminates at an end surface thereof for conducting light from a light source to the optical switch mechanism. A flexible film, whose surface is conditioned to provide at least two different fluorescent surfaces, is positioned such that an end surface of the actuator abuts the film throughout its movement from one position to another. A detector means detects light emitted from the film and returned by the fiber means. The actuator is movable so as to direct light from the light fiber means to different fluorescent surfaces of the film. The detector means detects light emitted from the film so as to determine from which fluorescent surface of the film light has been emitted.
The film may have a fluorescent surface and a non-fluorescent surface.
Alternatively, the film may have multiple fluorescent surfaces that emit at different wavelength regions. In this case the detectors would have corresponding filters that would enable them to detect multiple switch states.
Alternatively, fluorescent targets with graduated strength of emission may be employed for use as continuously variable controllers.
A major advantage of the flexible film abutting the end of the actuator or fiber is the insensitivity of that arrangement to film misalignment. The flexible film conforms to the face of the fiber or actuator, thereby maintaining the parallelism between film and fiber surfaces that are necessary to achieve high coupling efficiency.
Further, by arranging the end of the fiber to abut the flexible film throughout its range of movement, contamination of the area between the fiber and film with fluids or air-borne particulate is greatly reduced.
The light fiber means may be a single optical fiber or a group of fibers providing a single optical path to and from the switching actuator.
A directional coupler may be coupled to the light fiber means to direct light returning from the optical switch mechanism to the detector means. The detector means may include a photo detector positioned to detect light emitted from the film.
Other objects and advantages of the invention will become clear from the following detailed description of the preferred embodiment, which is presented by way of illustration only and without limiting the scope of the invention to the details thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof, will be best understood by reference to the description which follows, read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a side elevation view in section of an electrosurgical pencil with the halves of the casing slightly separated;
FIG. 2 is a side elevation view of an electrosurgical pencil with the two halves of the casing separated and the switching actuator detached;
FIG. 3 is a plan view of electrosurgical pencil with the switching actuator removed from view;
FIG. 4 is a partial sectional view in side elevation of the device an electrosurgical pencil showing the switching actuator and the fluorescent target assembly;
FIG. 5 is a partial sectional view in side elevation of a flexible filter and an end of a switching actuator, showing the fiber tip aligned to the central section of a fluorescent target film;
FIG. 6 is a partial sectional view of a portion of a flexible film showing the structural detail including three fluorescent sections, an intermediate transparent section and a transparent protective coating;
FIG. 7 is a schematic diagram of a single fiber switching system in which the film has a central fluorescent r___~..._.... _._..
area and two adjacent different fluorescent wavelength areas;
FIG. 8 is a partial sectional view in side elevation of the end of a switching actuator, showing the fiber tip aligned to the upper section of a film, having two different fluorescent surfaces;
FIG. 9 is a schematic view of system utilizing a send fiber and a receive fiber;
FIG. 10 is a schematic view of a single fiber system in which light of a shorter wavelength light emitting diode is collected into one fiber and two filtered detectors detect and decode the emitted fluorescent light;
FIG. 11 is a schematic view of the energy transfer process at the atomic level that occurs during fluorescence;
and FIG 12 is a graph that represents a typical example of the Stokes Shift in emission wavelength characteristic of fluorescence.
FIG. 2 is a side elevation view of an electrosurgical pencil with the two halves of the casing separated and the switching actuator detached;
FIG. 3 is a plan view of electrosurgical pencil with the switching actuator removed from view;
FIG. 4 is a partial sectional view in side elevation of the device an electrosurgical pencil showing the switching actuator and the fluorescent target assembly;
FIG. 5 is a partial sectional view in side elevation of a flexible filter and an end of a switching actuator, showing the fiber tip aligned to the central section of a fluorescent target film;
FIG. 6 is a partial sectional view of a portion of a flexible film showing the structural detail including three fluorescent sections, an intermediate transparent section and a transparent protective coating;
FIG. 7 is a schematic diagram of a single fiber switching system in which the film has a central fluorescent r___~..._.... _._..
area and two adjacent different fluorescent wavelength areas;
FIG. 8 is a partial sectional view in side elevation of the end of a switching actuator, showing the fiber tip aligned to the upper section of a film, having two different fluorescent surfaces;
FIG. 9 is a schematic view of system utilizing a send fiber and a receive fiber;
FIG. 10 is a schematic view of a single fiber system in which light of a shorter wavelength light emitting diode is collected into one fiber and two filtered detectors detect and decode the emitted fluorescent light;
FIG. 11 is a schematic view of the energy transfer process at the atomic level that occurs during fluorescence;
and FIG 12 is a graph that represents a typical example of the Stokes Shift in emission wavelength characteristic of fluorescence.
DETAILED DESCRIPTION
Referring to FIG. 1, the casing of the electrosurgical pencil 9 is made up of two casing portions 10 and 12. The internal components of the pencil 9 are installed on the recess in casing portion 12. The components include an electrode 26 that passes through a sleeve 24 and has attached at its anterior end a conductive cable 28.
Conductive cable 28 is run along the bottom interior surface of the casing portion 12 entering a cable sleeve 34 before exiting through the rear aperture 36 of the pencil 9.
Voltage applied to conductive cable 28 by a remote power source (not shown) is controlled by means of an optical fiber switching assembly composed of a light fiber 42 that runs within cable sleeve 34 adjacent to conductive cable 28 within the cable sleeve 34. The light fiber 42 is captured by switching actuator 20. The light fiber 42 runs all the way through the interior of the switching actuator 20.
Referring to FIG. 2, switching actuator 20 is pivotally attached to a pair of spaced apart mounting brackets 23 by means of pivotal pins 22 that project from either side of the switching actuator 20 and fit into receptacles in the mounting brackets 23. The switching actuator 20 has a pair of protruding knobs 30 and 32 at opposite ends thereof. The knobs 30 and 32 pass through apertures 14 and 16, respectively, in casing portion 10 when the two casing portions 10 and 12 are engaged. The optical fiber 42 passes through the switching actuator 20 and ends at end face 40.
In turn, the switching actuator 20 is pivotally mounted on mounting brackets 23, and end face 40 abuts or is placed in close proximity to flexible film 11.
Referring to FIG. 3, a top view of the device of FIGS.
1 and 2 without the switching actuator 20 in place is shown.
On the base of the casing portion 12 between mounting brackets 23 there are located two spring pads 44. The spring pads 44 are more clearly shown in FIG. 4 as consisting of a slightly convex sheet material mounted within a shallow circular receptacle. Contact projections 54 and 56 of the switching actuator 20 abut the spring pads 44 when in position. At the same time, end face 40 abuts the flexible film 11 as shown. When knob 30 is depressed, switching actuator 20 pivots about pins 22. Further, the depression of knob 30 causes contact projection 54 to depress spring pad 44 and further causes end face 40 to move upwardly while maintaining contact with flexible film 11.
Alternatively, depression of knob 32 causes contact projection 56 to depress spring pad 44 and further causing end face 40 to move downwardly while maintaining contact with flexible film 11. The spring pads 44 ensure that without pressure on either knob 30 or 32, the switching actuator 20 will be maintained in an intermediate position.
Referring to FIGS. 5 and 6, the mounting arrangement of flexible film 11 is shown as consisting of mounting bracket 60 affixed to casing half 12 and fitting between a recess 25 formed by projecting elements 19 and 21 belonging to casing portion 10. Flexible film 11 is positioned so that it is locked in position between recess 25 and mounting bracket 60. The flexible film 11 is cemented in a trough 31 at the base of mounting bracket 60.
In the preferred embodiment, flexible film 11 is Mylar having a mirror surface 18 formed of an aluminum film on its surface remote from end face 40. The flexible film 11 has a fluorescent coating 13 formed adjacent one side of a central fluorescent portion 15 and another fluorescent coating 17 of a different emission color formed on the other side thereof.
A protective coating 41 overlays the flexible film 11 to protect it from scratching.
In the intermediate position, the end face 40 is positioned against the central fluorescent target 15 in which flexible film 11 emits a wavelength band that brackets the wavelengths detected by both optically filtered detectors. Most of the light that exits optical fiber 42 excites fluorescence in flexible film 11 and emitted fluorescent light is returned back along optical fiber 42.
Due to the contact that is maintained between the flexible film 11, the switching actuator 20 and optical fiber 42, there is limited back scattering and loss of light due to contamination. When end face 40 abuts fluorescent target 13, light emanating from optical fiber 42 passes into fluorescent target 13, inducing fluorescence which is emitted directly into optical fiber 42 or reflected from surface 18 and returned into optical fiber 42. Similarly, when switching actuator 20 is pivoted so that end face 40 abuts the fluorescent target 17, a similar effect is produced.
Referring to FIG. 7, a broad band (multi-spectral) light source 71 emits light onto a parabolic reflector 73 that directs the reflected light into a ferrule 75 coupled to an optical fiber 77. Light from the optical fiber 77 enters a directional coupler 43, which directs approximately half of the light into fiber 81. The directional coupler 43 is usually a beam splitter but may also be a butt coupling of fibers or a graded index rod lens as is known in the art.
The directional coupler 43 is equipped with a wavelength selection filter to select an appropriate excitation wavelength. Alternatively the wavelength selection filter _T.__.~._ _...-_. . _ may be incorporated into the reflector or exit window of light source 71, 72. Light travels down fiber 81 into electrosurgical pencil 9. Light emerging from the end of fiber 81 is incident on one of three areas of flexible film 11. Central broad-band fluorescent portion 15 emits fluorescence detectable by both detectors and enhanced by mirror surface 18 on the back while fluorescent surfaces 13 and 17 consist of a compound that emits in a wavelength detected by only one or the other of the detectors.
The emitted light enters into fiber 81 and travels down to directional coupler 43 where some of the light is directed into fiber 79 into beam splitter 70. Part of the light travels down fiber 83 and part down fiber 85. Filters 72 and 74 are complementary to filters 13 and 17, respectively, and are used to determine in which of the three positions the end face 40 of pencil 9 is located, in order to discriminate the wavelength components contained in the emitted light. For example, if the light was passed first to a red emitting fluorescent surface and the emitted fluorescence then collected back into the fiber, by passing the filtered light through a complementary corresponding filter, it can be determined whether or not the end face was abutting the red fluorescent surface. Similarly, by using a green emitting fluorescent surface on the other side of the central portion of the flexible film 11 and passing the corresponding emitted light through a corresponding filter, it can be determined whether or not the end face 40 was abutting the green fluorescent surface. Detectors 76 and 78 detect any light that may be transmitted through the corresponding filters 72 and 74.
By utilizing a fluorescent surface in contact with the optical fiber, sufficient contrast and efficiency of excitation and emission takes place to allow the different switching states to be determined. The absence of any gaps makes the switching assembly less sensitive to contaminants from adverse environments including fluids and air-borne particulate that may coat the optical faces if they are otherwise separated. The absence of any gap also makes the switching assembly insensitive to normal optical losses from separation between any source and receiver of similar dimensions and numerical aperture.
Referring to FIG. 8 there is shown a flexible film 11 having only two surfaces. Surface 45 is non-fluorescent while surface 47 is fluorescent. Consequently, a single photo detector 76 with an excitation blocking long-pass filter or emission bandpass filter 72 in FIG. 9 will suffice to detect the two different positions and hence two states of the actuator or switching actuator 20.
Referring to FIGS. 6 and 9, a blue light emitting diode 88 is focused by lens 87 onto ferrule 48. The light enters fiber 90 and conducts to coupler 92 where the send and return fibers are bundled into fiber assembly 100. The blue light arrives at switching actuator 20 from which it is emitted and is incident upon the flexible film 11. The light passes through the clear protective coating 41 and excites fluorescence in the fluorescent material. Some fluorescent light is emitted and directly enters the optical fiber and some passes through flexible film 11 and is reflected from the mirror surface 18. The emitted light enters return fiber 91 and is conducted to dichroic optical block 87. Optical block 87 collimates the beam emitted from fiber 90 and spectrally splits the beam into two paths, which are focused onto a dual detector assembly 89. The gap that would normally be required in order to couple light from one fiber to the other is substituted for by protective clear coating 41 which acts as a spacer and provides a smooth surface for contact with end face 40 and prevents abrasion of the flexible film 11, contamination and other problems that attenuate the light.
It is clear that the electrosurgical pencil 9 is but one of may different devices in which the invention could be employed. For example, the invention could be incorporated into an ordinary dual or multistate switch on a switch panel. It could be used to detect slight misalignment on critical machine parts but replacing the single mirrored surface on the back of the flexible film il with a film with one having a graded filter. A slight change in alignment of the latter would change the amount of reflected light entering the fiber.
In an alternate embodiment of the invention, the coupler may consist of an excitation light source, an optical assembly to direct the excitation light into the surgical pencil assembly connector and collect the fluorescent emission from the surgical pencil assembly, a means to separate the light emitted from the fluorescent target into particular wavelength regions to be detected and a plurality of detectors to detect these wavelengths In a further alternate embodiment of the invention the coupler optical assembly consists of a lens to collimate light from the excitation source and direct it through a dichroic mirror oriented at an angle of 45 degrees to the optical axis of the collimated beam, and that passes the shorter wavelength light excitation light of the excitation source.
In still a further alternate embodiment of the invention, the coupler may consist of an excitation light source, an optical assembly to direct the excitation light into the surgical pencil assembly connector and collect the fluorescent emission from the surgical pencil assembly, a means to separate the light emitted from the fluorescent target into particular wavelength regions to be detected and a plurality of detectors to detect these wavelengths.
In still a further alternate embodiment of the invention, the optical assembly within the coupler may consist of an arrangement of fibers that conducts light from the illumination source to the optical switch fiber and collects light from the optical switch fiber and directs it to two or more optically filtered photo detectors.
In still a further alternate embodiment of the invention, it is possible to avoid the need for a directional coupler between the light source and the detectors by using a plurality of light fibers in a bundle with only some coupled to the light source and only the remainder coupled to the detector(s). However, in order for a dual fiber path system to work a gap must be provided between the mirror surface and the fibers, so that some off axis rays can couple from one fiber to the other.
A dual fiber system can avoid the problems associated with gap contamination and other problems that attenuate the light by providing a transparent layer of selected thickness in front of the fluorescent surface. The flexible film may be transparent of the selected thickness with a mirror coating on the back so that the film itself provides the requisite spacing without permitting the entry of contamination.
Accordingly, in certain aspects the present invention provides controllers and surgical pencil assemblies, the surgical pencil assembly comprising: a handpiece, hand actuated switch, cable and connector incorporating an optical path including a proximal end and a distal end, the handpiece being configured to position the distal end of the optical path to the fluorescent target; a light emitter window proximate to the distal end to direct an illumination light to the fluorescent target and collect the emitted light from the target; a controller assembly coupled to the connector of the surgical pencil assembly at the proximal end comprising an optical or fiber optic light guide to receive emanating light conducted to the proximal end of the surgical pencil assembly from the fluorescent target by the surgical pencil assembly light guide and an optical system to conduct the emanating light along at least a portion of a light path to the detector assembly; a wavelength selection filter aligned with the collection light guide to be disposed in the light path, the wavelength selection filter assembly selectively transmitting one or more desired wavelength bands of the emanating light.
In still further preferred embodiments, the controller further comprises a band pass filter maintained at the proximal end of the excitation light optical path and disposed between the excitation light emitter and the excitation light optical path, wherein the band pass filter transmits a selected wavelength band of light. The selected wavelength band can be a suitable wavelength of light able to induce fluorescence in the surgical pencil assembly fluorescent target.
In still further preferred embodiments, the illumination light transmitted to the target consists essentially of a selected wavelength band and the light collection system further comprises a long pass filter disposed in the light path, wherein the long pass filter blocks light having about the same wavelength as the selected wavelength band and transmits other light; the long pass filter can be disposed at the distal end of the light collection system and can block blue light if desired.
The wavelength selection filter assembly can be maintained upstream in the light path from the long pass filter or the long pass filter can be maintained upstream in the light path from the wavelength selection filter assembly, and the long pass filter can be maintained upstream from the collection light guide.
In still further embodiments of the invention, the present invention provides for surgical pencil assemblies, the surgical pencil assembly comprising: a body including a proximal end and a distal end, the body being configured to position the distal end of the optical path proximate to the fluorescent target, means for emitting an illumination light from a location of the body at least proximate to the distal end; means for collecting and conducting an emanating light from the fluorescent target along a light path to a controller assembly coupled to the connector of the surgical pencil assembly at the proximal end, the controller comprising an optical or fiber optic light guide to receive emanating light conducted to the proximal end of the surgical pencil assembly from the fluorescent target by the surgical pencil assembly light guide and an optical system to conduct the emanating light along at least a portion of a light path to the detector assembly; a wavelength selection filter aligned with the collection light guide to be disposed in the light path, the wavelength selection filter assembly selectively transmitting one or more desired wavelength bands of the emanating light.
In certain preferred embodiments, the target is illuminated by conducting the illumination light from a light source maintained at the proximal end of the surgical pencil assembly to a light emitter maintained at the distal end of the surgical pencil assembly switch via an illumination light guide and then emitting the illumination light to the fluorescent target.
In further preferred embodiments, the illumination light is transmitted through a band pass filter maintained at the distal end of the surgical pencil assembly, wherein the band pass filter transmits a selected wavelength band of light and blocks other light. The selected wavelength band can be light able to induce fluorescence in the fluorescent target.
In other preferred embodiments, the illumination light emitted from the light emitter consists essentially of a selected wavelength band and the light collection system further comprises a long pass filter disposed in the light path, wherein the long pass filter blocks light having about the same wavelength as the selected wavelength band and transmits other light.
In some preferred embodiments, the illumination light is conducted from a light source maintained at the proximal end of the surgical pencil assembly and the controller assembly to the light emitter at the distal end of the surgical pencil assembly via the illumination light guide, and wherein a band pass filter that transmits substantially only a desired wavelength region of excitation light is disposed at the distal end of the illumination light guide.
T .__- __ __ ____ In other preferred embodiments, the controller assembly comprises a fixed lens that is matched to the numerical aperture of the light guide of the surgical pencil assembly.
This lens collects collimated light from the illumination path and focuses and transmits it into the optical light guide at the proximal end of the surgical pencil assembly.
It also collects and collimates light emitted from the proximal end of the surgical pencil assembly light guide and delivers it into the optical path of the controller detector assembly. The emitted light being transmitted along the light path passes through optical transmissive and reflective filters that select and dispose the light toward the detectors.
In further aspects of the invention light from the excitation source is coupled into a lens that collects and collimates the excitation light and delivers it into the optical filter assembly and then to the lens that couples the excitation light into the light guide of the surgical handpiece.
In still more aspects, the present invention provides filter assemblies for a surgical pencil assembly to transmit the emission from the fluorescent target to a controller/detector, comprising: a casing including a distal end with a first opening to receive a proximal section of the surgical pencil assembly, and a transmission passage extending between the opening and the detector detectors, the transmission passage being configured to transmit light along a light path from the distal end to the proximal end of the casing; a rotatable housing attached to the casing, the rotatable housing including a knob configured to be gripped by a user and a filter holder positioned in the casing, the filter holder having a plurality of windows;
and, at least one filter received in one of the windows, the housing rotating within the casing to position the at least one filter in alignment with the light path for selectively configuring the controller for different devices.
In other preferred embodiments, the filter assembly further comprises a fixed lens that is matched to the numerical aperture of the light guide of the surgical pencil assembly.
This lens collects and collects and collimates light from the proximal end of the surgical pencil.
Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense.
Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is, therefore, contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.
Referring to FIG. 1, the casing of the electrosurgical pencil 9 is made up of two casing portions 10 and 12. The internal components of the pencil 9 are installed on the recess in casing portion 12. The components include an electrode 26 that passes through a sleeve 24 and has attached at its anterior end a conductive cable 28.
Conductive cable 28 is run along the bottom interior surface of the casing portion 12 entering a cable sleeve 34 before exiting through the rear aperture 36 of the pencil 9.
Voltage applied to conductive cable 28 by a remote power source (not shown) is controlled by means of an optical fiber switching assembly composed of a light fiber 42 that runs within cable sleeve 34 adjacent to conductive cable 28 within the cable sleeve 34. The light fiber 42 is captured by switching actuator 20. The light fiber 42 runs all the way through the interior of the switching actuator 20.
Referring to FIG. 2, switching actuator 20 is pivotally attached to a pair of spaced apart mounting brackets 23 by means of pivotal pins 22 that project from either side of the switching actuator 20 and fit into receptacles in the mounting brackets 23. The switching actuator 20 has a pair of protruding knobs 30 and 32 at opposite ends thereof. The knobs 30 and 32 pass through apertures 14 and 16, respectively, in casing portion 10 when the two casing portions 10 and 12 are engaged. The optical fiber 42 passes through the switching actuator 20 and ends at end face 40.
In turn, the switching actuator 20 is pivotally mounted on mounting brackets 23, and end face 40 abuts or is placed in close proximity to flexible film 11.
Referring to FIG. 3, a top view of the device of FIGS.
1 and 2 without the switching actuator 20 in place is shown.
On the base of the casing portion 12 between mounting brackets 23 there are located two spring pads 44. The spring pads 44 are more clearly shown in FIG. 4 as consisting of a slightly convex sheet material mounted within a shallow circular receptacle. Contact projections 54 and 56 of the switching actuator 20 abut the spring pads 44 when in position. At the same time, end face 40 abuts the flexible film 11 as shown. When knob 30 is depressed, switching actuator 20 pivots about pins 22. Further, the depression of knob 30 causes contact projection 54 to depress spring pad 44 and further causes end face 40 to move upwardly while maintaining contact with flexible film 11.
Alternatively, depression of knob 32 causes contact projection 56 to depress spring pad 44 and further causing end face 40 to move downwardly while maintaining contact with flexible film 11. The spring pads 44 ensure that without pressure on either knob 30 or 32, the switching actuator 20 will be maintained in an intermediate position.
Referring to FIGS. 5 and 6, the mounting arrangement of flexible film 11 is shown as consisting of mounting bracket 60 affixed to casing half 12 and fitting between a recess 25 formed by projecting elements 19 and 21 belonging to casing portion 10. Flexible film 11 is positioned so that it is locked in position between recess 25 and mounting bracket 60. The flexible film 11 is cemented in a trough 31 at the base of mounting bracket 60.
In the preferred embodiment, flexible film 11 is Mylar having a mirror surface 18 formed of an aluminum film on its surface remote from end face 40. The flexible film 11 has a fluorescent coating 13 formed adjacent one side of a central fluorescent portion 15 and another fluorescent coating 17 of a different emission color formed on the other side thereof.
A protective coating 41 overlays the flexible film 11 to protect it from scratching.
In the intermediate position, the end face 40 is positioned against the central fluorescent target 15 in which flexible film 11 emits a wavelength band that brackets the wavelengths detected by both optically filtered detectors. Most of the light that exits optical fiber 42 excites fluorescence in flexible film 11 and emitted fluorescent light is returned back along optical fiber 42.
Due to the contact that is maintained between the flexible film 11, the switching actuator 20 and optical fiber 42, there is limited back scattering and loss of light due to contamination. When end face 40 abuts fluorescent target 13, light emanating from optical fiber 42 passes into fluorescent target 13, inducing fluorescence which is emitted directly into optical fiber 42 or reflected from surface 18 and returned into optical fiber 42. Similarly, when switching actuator 20 is pivoted so that end face 40 abuts the fluorescent target 17, a similar effect is produced.
Referring to FIG. 7, a broad band (multi-spectral) light source 71 emits light onto a parabolic reflector 73 that directs the reflected light into a ferrule 75 coupled to an optical fiber 77. Light from the optical fiber 77 enters a directional coupler 43, which directs approximately half of the light into fiber 81. The directional coupler 43 is usually a beam splitter but may also be a butt coupling of fibers or a graded index rod lens as is known in the art.
The directional coupler 43 is equipped with a wavelength selection filter to select an appropriate excitation wavelength. Alternatively the wavelength selection filter _T.__.~._ _...-_. . _ may be incorporated into the reflector or exit window of light source 71, 72. Light travels down fiber 81 into electrosurgical pencil 9. Light emerging from the end of fiber 81 is incident on one of three areas of flexible film 11. Central broad-band fluorescent portion 15 emits fluorescence detectable by both detectors and enhanced by mirror surface 18 on the back while fluorescent surfaces 13 and 17 consist of a compound that emits in a wavelength detected by only one or the other of the detectors.
The emitted light enters into fiber 81 and travels down to directional coupler 43 where some of the light is directed into fiber 79 into beam splitter 70. Part of the light travels down fiber 83 and part down fiber 85. Filters 72 and 74 are complementary to filters 13 and 17, respectively, and are used to determine in which of the three positions the end face 40 of pencil 9 is located, in order to discriminate the wavelength components contained in the emitted light. For example, if the light was passed first to a red emitting fluorescent surface and the emitted fluorescence then collected back into the fiber, by passing the filtered light through a complementary corresponding filter, it can be determined whether or not the end face was abutting the red fluorescent surface. Similarly, by using a green emitting fluorescent surface on the other side of the central portion of the flexible film 11 and passing the corresponding emitted light through a corresponding filter, it can be determined whether or not the end face 40 was abutting the green fluorescent surface. Detectors 76 and 78 detect any light that may be transmitted through the corresponding filters 72 and 74.
By utilizing a fluorescent surface in contact with the optical fiber, sufficient contrast and efficiency of excitation and emission takes place to allow the different switching states to be determined. The absence of any gaps makes the switching assembly less sensitive to contaminants from adverse environments including fluids and air-borne particulate that may coat the optical faces if they are otherwise separated. The absence of any gap also makes the switching assembly insensitive to normal optical losses from separation between any source and receiver of similar dimensions and numerical aperture.
Referring to FIG. 8 there is shown a flexible film 11 having only two surfaces. Surface 45 is non-fluorescent while surface 47 is fluorescent. Consequently, a single photo detector 76 with an excitation blocking long-pass filter or emission bandpass filter 72 in FIG. 9 will suffice to detect the two different positions and hence two states of the actuator or switching actuator 20.
Referring to FIGS. 6 and 9, a blue light emitting diode 88 is focused by lens 87 onto ferrule 48. The light enters fiber 90 and conducts to coupler 92 where the send and return fibers are bundled into fiber assembly 100. The blue light arrives at switching actuator 20 from which it is emitted and is incident upon the flexible film 11. The light passes through the clear protective coating 41 and excites fluorescence in the fluorescent material. Some fluorescent light is emitted and directly enters the optical fiber and some passes through flexible film 11 and is reflected from the mirror surface 18. The emitted light enters return fiber 91 and is conducted to dichroic optical block 87. Optical block 87 collimates the beam emitted from fiber 90 and spectrally splits the beam into two paths, which are focused onto a dual detector assembly 89. The gap that would normally be required in order to couple light from one fiber to the other is substituted for by protective clear coating 41 which acts as a spacer and provides a smooth surface for contact with end face 40 and prevents abrasion of the flexible film 11, contamination and other problems that attenuate the light.
It is clear that the electrosurgical pencil 9 is but one of may different devices in which the invention could be employed. For example, the invention could be incorporated into an ordinary dual or multistate switch on a switch panel. It could be used to detect slight misalignment on critical machine parts but replacing the single mirrored surface on the back of the flexible film il with a film with one having a graded filter. A slight change in alignment of the latter would change the amount of reflected light entering the fiber.
In an alternate embodiment of the invention, the coupler may consist of an excitation light source, an optical assembly to direct the excitation light into the surgical pencil assembly connector and collect the fluorescent emission from the surgical pencil assembly, a means to separate the light emitted from the fluorescent target into particular wavelength regions to be detected and a plurality of detectors to detect these wavelengths In a further alternate embodiment of the invention the coupler optical assembly consists of a lens to collimate light from the excitation source and direct it through a dichroic mirror oriented at an angle of 45 degrees to the optical axis of the collimated beam, and that passes the shorter wavelength light excitation light of the excitation source.
In still a further alternate embodiment of the invention, the coupler may consist of an excitation light source, an optical assembly to direct the excitation light into the surgical pencil assembly connector and collect the fluorescent emission from the surgical pencil assembly, a means to separate the light emitted from the fluorescent target into particular wavelength regions to be detected and a plurality of detectors to detect these wavelengths.
In still a further alternate embodiment of the invention, the optical assembly within the coupler may consist of an arrangement of fibers that conducts light from the illumination source to the optical switch fiber and collects light from the optical switch fiber and directs it to two or more optically filtered photo detectors.
In still a further alternate embodiment of the invention, it is possible to avoid the need for a directional coupler between the light source and the detectors by using a plurality of light fibers in a bundle with only some coupled to the light source and only the remainder coupled to the detector(s). However, in order for a dual fiber path system to work a gap must be provided between the mirror surface and the fibers, so that some off axis rays can couple from one fiber to the other.
A dual fiber system can avoid the problems associated with gap contamination and other problems that attenuate the light by providing a transparent layer of selected thickness in front of the fluorescent surface. The flexible film may be transparent of the selected thickness with a mirror coating on the back so that the film itself provides the requisite spacing without permitting the entry of contamination.
Accordingly, in certain aspects the present invention provides controllers and surgical pencil assemblies, the surgical pencil assembly comprising: a handpiece, hand actuated switch, cable and connector incorporating an optical path including a proximal end and a distal end, the handpiece being configured to position the distal end of the optical path to the fluorescent target; a light emitter window proximate to the distal end to direct an illumination light to the fluorescent target and collect the emitted light from the target; a controller assembly coupled to the connector of the surgical pencil assembly at the proximal end comprising an optical or fiber optic light guide to receive emanating light conducted to the proximal end of the surgical pencil assembly from the fluorescent target by the surgical pencil assembly light guide and an optical system to conduct the emanating light along at least a portion of a light path to the detector assembly; a wavelength selection filter aligned with the collection light guide to be disposed in the light path, the wavelength selection filter assembly selectively transmitting one or more desired wavelength bands of the emanating light.
In still further preferred embodiments, the controller further comprises a band pass filter maintained at the proximal end of the excitation light optical path and disposed between the excitation light emitter and the excitation light optical path, wherein the band pass filter transmits a selected wavelength band of light. The selected wavelength band can be a suitable wavelength of light able to induce fluorescence in the surgical pencil assembly fluorescent target.
In still further preferred embodiments, the illumination light transmitted to the target consists essentially of a selected wavelength band and the light collection system further comprises a long pass filter disposed in the light path, wherein the long pass filter blocks light having about the same wavelength as the selected wavelength band and transmits other light; the long pass filter can be disposed at the distal end of the light collection system and can block blue light if desired.
The wavelength selection filter assembly can be maintained upstream in the light path from the long pass filter or the long pass filter can be maintained upstream in the light path from the wavelength selection filter assembly, and the long pass filter can be maintained upstream from the collection light guide.
In still further embodiments of the invention, the present invention provides for surgical pencil assemblies, the surgical pencil assembly comprising: a body including a proximal end and a distal end, the body being configured to position the distal end of the optical path proximate to the fluorescent target, means for emitting an illumination light from a location of the body at least proximate to the distal end; means for collecting and conducting an emanating light from the fluorescent target along a light path to a controller assembly coupled to the connector of the surgical pencil assembly at the proximal end, the controller comprising an optical or fiber optic light guide to receive emanating light conducted to the proximal end of the surgical pencil assembly from the fluorescent target by the surgical pencil assembly light guide and an optical system to conduct the emanating light along at least a portion of a light path to the detector assembly; a wavelength selection filter aligned with the collection light guide to be disposed in the light path, the wavelength selection filter assembly selectively transmitting one or more desired wavelength bands of the emanating light.
In certain preferred embodiments, the target is illuminated by conducting the illumination light from a light source maintained at the proximal end of the surgical pencil assembly to a light emitter maintained at the distal end of the surgical pencil assembly switch via an illumination light guide and then emitting the illumination light to the fluorescent target.
In further preferred embodiments, the illumination light is transmitted through a band pass filter maintained at the distal end of the surgical pencil assembly, wherein the band pass filter transmits a selected wavelength band of light and blocks other light. The selected wavelength band can be light able to induce fluorescence in the fluorescent target.
In other preferred embodiments, the illumination light emitted from the light emitter consists essentially of a selected wavelength band and the light collection system further comprises a long pass filter disposed in the light path, wherein the long pass filter blocks light having about the same wavelength as the selected wavelength band and transmits other light.
In some preferred embodiments, the illumination light is conducted from a light source maintained at the proximal end of the surgical pencil assembly and the controller assembly to the light emitter at the distal end of the surgical pencil assembly via the illumination light guide, and wherein a band pass filter that transmits substantially only a desired wavelength region of excitation light is disposed at the distal end of the illumination light guide.
T .__- __ __ ____ In other preferred embodiments, the controller assembly comprises a fixed lens that is matched to the numerical aperture of the light guide of the surgical pencil assembly.
This lens collects collimated light from the illumination path and focuses and transmits it into the optical light guide at the proximal end of the surgical pencil assembly.
It also collects and collimates light emitted from the proximal end of the surgical pencil assembly light guide and delivers it into the optical path of the controller detector assembly. The emitted light being transmitted along the light path passes through optical transmissive and reflective filters that select and dispose the light toward the detectors.
In further aspects of the invention light from the excitation source is coupled into a lens that collects and collimates the excitation light and delivers it into the optical filter assembly and then to the lens that couples the excitation light into the light guide of the surgical handpiece.
In still more aspects, the present invention provides filter assemblies for a surgical pencil assembly to transmit the emission from the fluorescent target to a controller/detector, comprising: a casing including a distal end with a first opening to receive a proximal section of the surgical pencil assembly, and a transmission passage extending between the opening and the detector detectors, the transmission passage being configured to transmit light along a light path from the distal end to the proximal end of the casing; a rotatable housing attached to the casing, the rotatable housing including a knob configured to be gripped by a user and a filter holder positioned in the casing, the filter holder having a plurality of windows;
and, at least one filter received in one of the windows, the housing rotating within the casing to position the at least one filter in alignment with the light path for selectively configuring the controller for different devices.
In other preferred embodiments, the filter assembly further comprises a fixed lens that is matched to the numerical aperture of the light guide of the surgical pencil assembly.
This lens collects and collects and collimates light from the proximal end of the surgical pencil.
Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense.
Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is, therefore, contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.
Claims (18)
1. A fiber optical switching system for use with a light source and detector, comprising:
a) an optical switch having a movable actuator;
b) an optical fiber coupled to said actuator and terminating substantially at an end surface thereof for conducting light from the light source to said optical switch mechanism;
c) a flexible film, or other mechanical element whose surface is conditioned to provide at least two fluorescent surfaces that when illuminated by light of a shorter wavelength , will emit light at a longer wavelength and d) each of the two or more fluorescent surfaces emit light in different wavelength regions when excited by the same shorter wavelength illumination and e) are positioned such that an end surface of said optical fiber abuts or is placed in close proximity to said film throughout its movement from one fluorescent surface to another, wherein light emitted by said fluorescent surface is collected by said optical fiber; and f) a detector coupled to an end of said optical fiber for detecting light emitted from said fluorescent film into said optical fiber so as to determine from which fluorescent surface of said film light has been emitted.
a) an optical switch having a movable actuator;
b) an optical fiber coupled to said actuator and terminating substantially at an end surface thereof for conducting light from the light source to said optical switch mechanism;
c) a flexible film, or other mechanical element whose surface is conditioned to provide at least two fluorescent surfaces that when illuminated by light of a shorter wavelength , will emit light at a longer wavelength and d) each of the two or more fluorescent surfaces emit light in different wavelength regions when excited by the same shorter wavelength illumination and e) are positioned such that an end surface of said optical fiber abuts or is placed in close proximity to said film throughout its movement from one fluorescent surface to another, wherein light emitted by said fluorescent surface is collected by said optical fiber; and f) a detector coupled to an end of said optical fiber for detecting light emitted from said fluorescent film into said optical fiber so as to determine from which fluorescent surface of said film light has been emitted.
2. A system according to claim 1, wherein said film has a fluorescent coating applied to a surface furthest from the end surface of said optical fiber and said film against which the fluorescent coating is applied emits light in a selected wavelength region when excited by illumination by light of a shorter wavelength
3. A system according to claim 1, including a directional coupler coupled to said optical fiber means to direct light returning from said optical switch to said detector means.
4. A system according to claim 1, wherein said detector means includes a photo detector positioned to detect light emitted from said film into said optical fiber means.
5. A system according to claim 1, wherein said film has a fluorescent surface abutting an end surface of said optical fiber in a first position of said actuator and a non-fluorescent surface abutting an end surface of said optical fiber in a second position of said actuator.
6. A system according to claim 1, wherein said film has more than two fluorescent surfaces and said detector means includes as many photo detectors and wavelength selective filters as there are fluorescent surfaces.
7. A system according to claim 1, wherein said film is Mylar.
8. A system according to claim 1, wherein said flexible film includes a transparent substrate, a mirror coating on a back surface of said substrate and fluorescent coatings on a front surface of said substrate.
9. A system according to claim 8 including a scratch resistant transparent coating over said film.
10. A system according to claim 1, including a light source emitting one wavelength region of light and wherein said fluorescent surfaces are conditioned to emit wavelengths matched to the wavelength of light reflected or transmitted from or through complimentary optical filters to two or more photo detectors, which will detect the respective wavelengths of light emitted
11. A fiber optical switching system, comprising:
a) a light source emitting a single wavelength region of light;
b) an optical switch having a movable actuator;
c) an optical fiber coupled to said actuator and terminating substantially at an end surface thereof for conducting light from said light source to said optical switch;
d) a flexible fluorescent film mounted in said optical switch having a plurality of different fluorescent surfaces and positioned such that an end surface of said optical fiber abuts or is placed in close proximity to said film as it moves among positions in which light from said light fiber means is incident on said fluorescent surfaces; and e) a plurality of photo detectors and associated filters, each photo detector and filter corresponding to a respective one of said fluorescent surfaces, said photo detectors and filters coupled to said optical fiber means and being operative to detect light emitted from said film into said optical fiber so as to permit determination of the location of said actuator.
a) a light source emitting a single wavelength region of light;
b) an optical switch having a movable actuator;
c) an optical fiber coupled to said actuator and terminating substantially at an end surface thereof for conducting light from said light source to said optical switch;
d) a flexible fluorescent film mounted in said optical switch having a plurality of different fluorescent surfaces and positioned such that an end surface of said optical fiber abuts or is placed in close proximity to said film as it moves among positions in which light from said light fiber means is incident on said fluorescent surfaces; and e) a plurality of photo detectors and associated filters, each photo detector and filter corresponding to a respective one of said fluorescent surfaces, said photo detectors and filters coupled to said optical fiber means and being operative to detect light emitted from said film into said optical fiber so as to permit determination of the location of said actuator.
12. A system according to claim 11, wherein said light fiber means provides a single light path to and from said optical switch mechanism.
13. A fiber optical switching system, comprising:
a) a light source emitting a single wavelength of light;
b) an optical switch having a movable actuator;
c) an input and output optical fiber coupled to said actuator and terminating substantially at an end surface thereof said input optical fiber for conducting light from said light source to said optical switch and said output optical fiber for conducting light from said optical switch;
d) a flexible fluorescent film mounted in said optical switch having a first fluorescent surface and a second fluorescent surface and positioned such that an end surface of said optical fibers abut said film as it moves from a position in which light from said input light fiber is incident on said first fluorescent surface to one in which it is incident on said second fluorescent surface; and e) a photo detector coupled to said second optical fiber and being operative to detect light emitted from said film into said second optical fiber so as to permit determination of the position of said actuator.
a) a light source emitting a single wavelength of light;
b) an optical switch having a movable actuator;
c) an input and output optical fiber coupled to said actuator and terminating substantially at an end surface thereof said input optical fiber for conducting light from said light source to said optical switch and said output optical fiber for conducting light from said optical switch;
d) a flexible fluorescent film mounted in said optical switch having a first fluorescent surface and a second fluorescent surface and positioned such that an end surface of said optical fibers abut said film as it moves from a position in which light from said input light fiber is incident on said first fluorescent surface to one in which it is incident on said second fluorescent surface; and e) a photo detector coupled to said second optical fiber and being operative to detect light emitted from said film into said second optical fiber so as to permit determination of the position of said actuator.
14. A system according to Claim 9 wherein said complimentary optical filters to two or more photo detectors, which will detect the respective wavelengths of light emitted, consists of:
a) a lens placed downstream from the light source to collimate the light emitted from the light source;
b) a dichroic filter placed in the path of the collimated light and downstream from the lens above and positioned 45 degrees off-axis to the optical fiber in the connector of the surgical pencil, that passes wavelengths of light emitted from the light source but reflects through ninety degrees longer wavelengths of light emitted via the optical fiber from the optical switch;
c) a lens placed downstream of the dichroic filter to focus collimated light from the light source into the optical fiber and to collimate light returning from the optical fiber;
d) a second dichroic filter placed at 45 degrees to and in the path of the collimated light emitted from the optical switch but reflected through ninety degrees from the first dichroic filter;
e) a detector positioned to collect the light transmitted through the second dichroic filter;
and f) a detector positioned to collect the light reflected from the second dichroic filter.
a) a lens placed downstream from the light source to collimate the light emitted from the light source;
b) a dichroic filter placed in the path of the collimated light and downstream from the lens above and positioned 45 degrees off-axis to the optical fiber in the connector of the surgical pencil, that passes wavelengths of light emitted from the light source but reflects through ninety degrees longer wavelengths of light emitted via the optical fiber from the optical switch;
c) a lens placed downstream of the dichroic filter to focus collimated light from the light source into the optical fiber and to collimate light returning from the optical fiber;
d) a second dichroic filter placed at 45 degrees to and in the path of the collimated light emitted from the optical switch but reflected through ninety degrees from the first dichroic filter;
e) a detector positioned to collect the light transmitted through the second dichroic filter;
and f) a detector positioned to collect the light reflected from the second dichroic filter.
15. A system according to Claim 14 wherein said dichroic filters are placed on the 90 degree angled surfaces of a 45 degree/45 degree/90 degree prism.
16. A system according to Claim 14 wherein multiple fibers from multiple optical switches are arranged in an array at the coupler input lens and where the second dichroic mirror is replaced by a focusing lens and an array or imaging sensor such as a colour CCD imaging device equipped with a red/green/blue matrix filter detects the emitted light from the array of optical switch fibers.
17. A system according to Claim 14 wherein multiple fibers from multiple optical switches are arranged in an array at the coupler input lens and where the second dichroic mirror has two focusing lenses placed downstream of the reflective and transmissive paths respectively and an array or imaging sensor such as a CCD imaging device detects the emitted light from the array of optical switch fibers.
18. A system according to Claim 14 wherein said second dichroic filter is replaced by a wavelength dispersive optical element such as a prism or diffraction grating and one or more photo detectors are placed in positions to detect the dispersed complimentary wavelength or wavelengths of light emitted by the optical switch.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2293094 CA2293094A1 (en) | 1999-12-23 | 1999-12-23 | Fluorescence based optical switch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2293094 CA2293094A1 (en) | 1999-12-23 | 1999-12-23 | Fluorescence based optical switch |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2293094A1 true CA2293094A1 (en) | 2001-06-23 |
Family
ID=4164953
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2293094 Abandoned CA2293094A1 (en) | 1999-12-23 | 1999-12-23 | Fluorescence based optical switch |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2293094A1 (en) |
-
1999
- 1999-12-23 CA CA 2293094 patent/CA2293094A1/en not_active Abandoned
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