CA2024480A1 - Method of and apparatus for measuring the dose or dose rate of nuclear radiation - Google Patents
Method of and apparatus for measuring the dose or dose rate of nuclear radiationInfo
- Publication number
- CA2024480A1 CA2024480A1 CA 2024480 CA2024480A CA2024480A1 CA 2024480 A1 CA2024480 A1 CA 2024480A1 CA 2024480 CA2024480 CA 2024480 CA 2024480 A CA2024480 A CA 2024480A CA 2024480 A1 CA2024480 A1 CA 2024480A1
- Authority
- CA
- Canada
- Prior art keywords
- sensor
- wave guide
- light
- radiation
- dose
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
- G02B6/38—Mechanical coupling means having fibre to fibre mating means
- G02B6/3807—Dismountable connectors, i.e. comprising plugs
- G02B6/3873—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls
- G02B6/3874—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls using tubes, sleeves to align ferrules
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/02—Dosimeters
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
- G02B6/38—Mechanical coupling means having fibre to fibre mating means
- G02B6/3807—Dismountable connectors, i.e. comprising plugs
- G02B6/3833—Details of mounting fibres in ferrules; Assembly methods; Manufacture
- G02B6/3854—Ferrules characterised by materials
Abstract
ABSTRACT OF THE DISCLOSURE
Nuclear radiation dose or dose rate in living tissue is determined in an on-line manner in situ by positioning at the nuclear irradiation site a length of an optical wave guide which may be passive, i.e. can receive a light beam from a source via a transmissive light wave guide, upon subjection of nuclear irradiation. The optical signal produced in the sensor is delivered to a detector and the analyzing circuitry by means of a transmissive light wave guide.
dm-
Nuclear radiation dose or dose rate in living tissue is determined in an on-line manner in situ by positioning at the nuclear irradiation site a length of an optical wave guide which may be passive, i.e. can receive a light beam from a source via a transmissive light wave guide, upon subjection of nuclear irradiation. The optical signal produced in the sensor is delivered to a detector and the analyzing circuitry by means of a transmissive light wave guide.
dm-
Description
METHOD OF AND APPARATVS FOR MEASURING THE DOSE OR DOSE
~A~E OF NUCLEAR RADIA~ION
SPECIFICATION
Field of ~he ~nyç~tion our present invention relates to a method of and to an apparatus for the measurement of the radiation dose or radiation dose rate of nuclear radiation, for example gamma radiation, alpha radiation and beta radiation, In sltu within the tissue of an organi~m which i~ to be sub~ected to that radiation.
B~ckgroun~ o~ ~hÇ I~vçntion In radiation therapy it iB des~rable to know the radiation dose or the radiation dose rate to which a particular organ or tissue location may be subject in the hu~an body or an animal body in the case of human therapy or veterinary therapy, respectively. Radiation therapy of this type may be used to reduce the size of or eliminate tumors or for other medical purposes. By and large, predetermined radiation doses or dose rates are required for specific organs, specific tumors or ~pecific ti6sues.
2024~80 of course, the radiation dose or dose rate can be calculated with respect to each particular location or site, based upon the known rate of incident radiation and ~actor~ such as ab~orption.
However, in many cases, and indeed in most cases it is recognized that an on-line monitoring of the radiation dose or dosa rate actually received at a particular location is desirable.
To the best of our knowledge, it has not been possible to monitor the radiation dose or dose rate during irradiation ln sl tu heretofore.
Ob~ect6 o~ 5he Invention It is, therefore, the principal object of the present invention to provide a method of determining the radiation dose or dose rate ln sltu and during irradiation in living tissue.
Another object is to provide an improved method of monitoring radiation therapy whereby drawbacks in earlier method3 can be avoided and in particular, radiation therapy can be more accurately controlled.
Still another object of the invention i~ to provide an improved sensor enabling the detection and measurement of the dose rate or radiation dose ln sltu within human tissue.
8um~a~y~s~the Inven~lo~
These ob~ects are attained, in accordance with the present invention in a method of measuring radiation dose or dose rate ln sltu within living tis6ue at a particular location subjected to nuclear radiation which comprises the steps of disposing at this lo¢ation a length o~ a ~ensing optical wave ?024480 guide, l.e. an optlcal fiber, manifesting a change in an optical characteristic upon being subjected to nuclear radiation, thereby generating an optical signal, transmitting the optical signal from this 6ensor optical wave guide through a transmission optical wave guide, e.g. an optical fiber or 60-called light pipe, to an electronic circuit capable of analyzing and transducing the optical signal into an electrical signal representing the radiation dose or do~e rate, and di6playing an electrical output representing the radlatlon dose or dose rate in an on-line manner during the irradiatlon of the ti~sue at the site.
According to the invention, the sen~or optical wave guide can be a passive 6ensor, i.e. a sensor in which the radiation induces a change in the optical characteristics of the sensor optical wave guide with respect to transmitted light which can be ~upplied to the sensor, the change in the tran~mitted light caused by the radiation in the sensor represents the optical signal which is transmitted through the transmission optical wave guide and i~ detected and analyzed.
According to a feature of the invention, in the use of a passive 6ensor as described, the incident light transmitted to the sensor can be transmitted through a transmi6sion optical wave guide, i.e. an optical fiber or light pipe and, preferably, the transmis~ion optical wave guide conveying the optical signal to the evaluation, measurement and display circuitry.
According to a feature of the invention, the sensor has a diameter which is less than 0.5 ~ and can be fed to the site or location to be irradiated through a cannula, catheter or other delivery tube which can be ~n~ertQd into 8 body duct such as a portion of the vasculature, respiratory, alimentary and/or intestinal tracts.
It has been found that best results are obtained in the detection of the local effects of nuclear radiation at the tissue site or location when the passive or act$ve light wave guide has a length of 10 to 50 mm.
According to another feature of the invention, one end of the passive or active light wave guide or optical flber con~tituting the sensor is mirrored and only the opposite end is connected with the transmiesion light wave guide.
According to the invention, when a passive sensor light wave guide is used, a coupling member, such as a Y coupler, can be used to deliver the incident radiation to the sensor and to the reference channel of the measurement electronics. When a common transmission light wave guide is used to deliver the incident radiation to the 6ensor and for transmission of the optical signal which i8 effected, a coupler, e.g. an X coupler or a Y
coupler, may be used for feeding the light to the sensor and recovering the optical signal therefrom.
It has been found to be advantageous to provide a passive light wave guide sen~or with light ~ources in the form of two luminescsnt diodes, i.e. light-emitting diodes or LED~, each of which can provide light of a respective wavelength (A 1 and)~2) such that the light of one o~ the diodes is sub~ected to a greater variation by the nuclear radiation than the light from the other diode, but the effect of the transmission light wave guide on both wave~ength~ do not dif~er 6ignific~ntly from one 202~480 177~7 another. The electronic~ can thus be provided to effect a comparison of the light from the two sources and the difference can be used to establish the do~e or dose rate.
The light of both light e~itting diodes can be amplitude s modulated with the modulation of the two diodes phase-shiftQd by 180- and the amplitude ratio of the light outputted by the two diodes can be set before irradiation of the site or location so that a nonmodulatQd measurQment signal is delivered to the circuit.
In a passive wave guide, it should be understood that in solid bodiQs and thus also in liqht wave guides, defect structures, for example, omitted, di~placed or offset latt$ce atoms, exchange of lattice atoms and like point defects, can be generated by particle $rradiation and gamma radiation, i.e.
nuclear radiation or can be effected by such nuclear radlatlon.
8uch nuclear radiation can effect change~ in the electronic band structure by the binding of free electron6 or holes at already-formed defect locations or at lattice defects created by the nuclear radiation These defects formed or lattice defect changes induced by nuclear radiation give rise to significant changes in the damping, refractive lndex or luminescence of a light wave guide through which light can be transmitted.
We will, therefore, distinguish her~in between pa6sive light optical wave guides which operate primarily by an absorption phenomenon or a phenomenon relatad to some other changes in the character of light, and active or scintillating light optical wave guides, ln which the incident radiation causes emission of photons.
.. . ~ . . . . .
2~2~480 177~7 The light wave gulde of the passive ~ensor does not emit of itself light quanta as a consequence of nuclear irradiation.
Its characteristic a6 a sensor i8 based, rather, ùpon the change ln the llght tranemi~sion characterl~tics (damping) induced by nuclear irradiation.
By appropriate doping of the liqht wave guide, it is possible to make the passive sensor selective for the dose range and radiation energy or range to which the sensor is to respond. ~y contrast, the transfer liqht wave guide can be designed not to affect the optical characteristics of transmission therealong and serves only to deliver the optical signal to the detector from the 6ensor.
Since the diameter of the light wave guide is very small, i.e. can be between 10 and 200 micrometers, the sensor, including its guide sleeve or tube, can have a diameter not in oxce~s of 0.5 mm and can be positioned with great aacuracy at the irradiation side in the living tissue utilizing the va~culature or other body pa6sages or by an invasive procedure in which the sensor i8 fed to the site through a tissue-tolerable duct, cannula or catheter.
In the case of radiation which is to be delivered with great accuracy to a particular location and wherein the measurement is desired with the highest possible resolution in terms of location, it is preferred to employ a sensor in the form of a light wave guide having a length of 10 mm to 50 mm.
For a passive sensor, hiqh sensitivity can be achieved through the use of lead-containing light wave guides, i.e.
so-called flint glass fiber~, a~ the sensor light wave guide.
- . - - . . . . . .... .... _ .. ......
~` 2024480 1~74~
In applications ~n which longer sen60rs are to be introduced, for example, germanium-doped glass fiber~ may be preferable.
In the measuring apparatus accordlng to the invention with which the method is carr$ed out, the passive sensor 1B
S eonneeted by a transmis6ion light wave guide with a measuring or analyzlng eircuit, i.e. the electronics of the apparatus.
This circuitry is so constructed that it receives the measurable optical signal on line and processes this signal to determine the dose or dose rate for direct display. The light source whieh iB necessary to "read" the sensor ean be supplied to the latter by the tran6mission light wave guide eonnected to the sensor.
The sensor can bQ connected by one transmission light wave guide with the light 60urcQ and by another transmission wave guide with the analyzing electronic circuitry. The light coming from the source can thus pass through the sensor to the analyzing electronics, the light in the sensor being sub~ected to the damping effect. The circuitry can include a reference ~ource whieh may be coupled to the original source 80 that the optical ~ignal whieh i8 deteeted is ln the form o~ a difference between the original light and the light transmitted through the sensor.
In medieal applications, a8 has previously been indicated, the mea~uring device with its sensor ehould have a diameter which does not exceed 0.5 mm.
It has been found to be especially advantageous to provide a sensor, one end of which i~ formed with a mirror surface and whieh ie internally reflected, and only the other end of whieh Z~4~0 I
i is connected with a transmitting light wave guide. This system is used with a mea~uring device in which a coupling member is connected to the transmitting light wavo guide and with other transmittlng light wave guides communicating with the light source and with the measuring or analyzing electronic circuitry, the transmitting light wave guide between the coupling element and the sensor being used to deliver the light to the sensor and for conducting the optical signal back to the circuitry.
The sensor with the mirrored end reflects the light within the sensor and thus the light traverses the sen~or twice and for a sensor of a given length, can provide twice the damping in response to a given nuclear radiation flux, than a sensor traveroed by the llght only once.
The u~e of two light-emitting diodes ae described allows the wavelengths of the lights of the two diodes to be chosen so that both are in the range in which the nuclear radiation will effect damp$ng within the sensor, thi6 range being wave-length dependent. In this case, the damping caused by the nuclear radiation is accentuated. In the case in which the input wavelengths are amplitude modulated 180' out of phase, a modulated measured signal can be a measure of the radiation effect and thus the radiation dose.
According to another feature of the invention, the sensor light wave guide 18 connected to the transmissive light wave guide in a unique manner, namely, by abutting the two wave guides and retaining them in end to end position by a metal sleeve.
- 2~2~480 177~7 I
We have found that a standard plug connection of the sen~or wave guide cannot always be used when the sensor wave guidQ 1B
to be located within the body of a patient to be sub~ected to the nuclear radiation. The ~tandard plug connection for optical fibers and, consequently, light wave guides, may have a diameter of 7 to 10 mm and a length up to 100 mm which is not amenable to $nsertion into the vasculature of the body or other passagQ~ therein to the site at which the irradiation i8 to take place.
It i8 also known to use a fusion technigue for ~oining glass fiber ends in a fusion ~plicing system. However, even this technique is not suitable where the radiation-6ensitive light wave guide has a high lead content a6 may be the case with the sensor~ of the invention. In fusion splicing technique~ the two glass fiber ends are brought to a temper~ture of about 2000-C in an electric arc which can cause burn off of the lead content of the sensor wave guide.
Temperatures exceeding 500-C will be destructive of the lead content of the ~ensor wave guide 80 that such a splicing technique canno,t be used.
According to the present invention, the uncoated sensor light wave guide i~ cemented by a biocompatible adhesive in a metal capillary or pure nickel or a oopper nickel alloy (80% by weight copper/20% by weight nickel) and the ends of the ~acketed sensor are ground and poli~hed. A mirror is for~ed at one end. The transmissive light wave guide, which is not sensitive to radiation, is likewise bonded in a capillary of the corre~ponding metal and it8 end i8 ground and polished.
202~480 The ground and polished end~ of the sen~or wave guide and the transmissive wave guide, without further optical binding material, are brought into abutting relationship end to end in a positioning metal capillary of the same metal and anchored therein by, for example, swaging the positioning capillary against the metal ~ackets of the 2 wave guides. Alternatively, I
the ends of the wave guides can be ~oined in the manner described and only therea~ter can mirroring of the free end of the sensor wave gulde be effected.
In the use of an active 6ensor, of course, the need for a light source i8 eliminated since the light pulse generated by scintillation upon nuclear irradiation of the sensor is directly a measure oS the dose rate.
~rief Descrip~ion of the Drawing lS The above and other ob~ects, features and advantages of the present invention will become more readily apparent fro~ the following description, reference being made to the acco~panying drawing in which:
FIG. 1 is a block diagram illustrating a sensor according to the invention connected at both ends with a transmitting optical wave guide;
FIG. 2 l~ a view si~ilar to FIG. 1 oS a measuring apparatus utilising a mirrored sensor:
FIG. 3 is a graph howing a damping characteristic of a passive sensor and the spectral distribution oS the radiation . power oS the light source:
FIG. 4 i6 a graph showing the radiation power~ at the light sourcQ and at the detector: and FIG. 5 is a cross sQctional view lllu~trating another feature of the invention.
speclfl~ ÇLi~Lnn FIG. 1 shows a mea~uring apparatuæ having two transmitting light wave guides 11 and 12 connected to opposite ends of a sQnsor light wave guide 13.
The circuitry 14 serves to excite the passive wave guide 13 and i~ connected to the wave guides 11 and 12 via light fiber plug connectors 15, 16, 17, 18. The sensor can be located in living tis6ue represented only diagrammatically at 19 and is in the location of the tissue which is subjected to the radiation field represented by the arrows 20 as a field derived from cobalt 60 irradiation of a patient The circuit 14 comprises a light-emitting diode 21 or some other lumine~cent diode having A wavelength, for example, of 560 nm.
~he output of the light-emitting diode Zl is applied to the transmitting llght wave guide 11 through a Y coupler 22, 10% of the output of which is fed by a light wave guide 23, e.g. at an optical fiber, to the reference channel of the circuitry prov~ded with a detector A transducing the optical signal delivered by the wave guide 23 into an electrical signal.
The balance of the light, i.e. 90% thereof and con~tituting the measuring light is fed through the Y coupler 22 to the transmitting liqht wave gulde 11 ~o that it passes through the 2~24~8~
~ensor 13. The attenu~ted or damplng signal i~ pa~sed via the transmitting optical wave guide 12 to the measuring channel of the circuitry and namely, a detector B ln the form of an optoelectrlcal tran~ducer whlch delivers lt~ signal to the evaluating or analysi6 ¢ircuitry represented at 2~. This cir-cuitry ha~ a display 25 and may include a microprocessor-based computer.
The sensor 13 is a light wave guide of lead-containing glass, e.g. flint glass. The optical damping or attenuation is lncreased when the sensor 18 sub~ected to the radiation field 80 that the nuclear radiation field produced by the cobalt 60urce, for example, produce~ a reduction in the light transmi~slvity of the sensor and thls can be detected at B as a reduction in llght transmissivity as a function of nuclear radiatlon dose. The light ~$gnals are transformed by the detectors A and B into electrical signals which are digitalized and the damping change or attenuation is plotted at 5 on a cathode ray screen or on a paper and ink recorder or the li~e.
The light sourc~ in this embodiment is comprised of the lumlne~cent dlode 21 and the Y coupler 22 while the ~easurement and evaluatlon circuitry comprlses the detector~ A and B of the refQrence and measurement channels and tbe unit 24, 25.
The sen~or can have a dlameter o~ ~ust under 0.5 mm and a length o~ 40 mm. A total doee o~ 60 Gy can be used to irradiate the tlssue. A series of tests have shown that thers i8 no signlflcant change in the detectlon sensitlvity over the total dose range.
. - 2024480 177~7 The detectlon ~en~itlvity wae det-rmlned by calibration measurements in a vater bath to be S x 10 3 Gy with the above-mentioned ~ensor dimeneione.
As a reproducibillty test, a test ser$es with four eeneore s of the same lengtb for a radlation cycle of 24 houre and individual dosages of about 2 Gy under the same te~t conditions were carried out. The maximum deviation of two meaeurements out of seven successive irradiations of the same ~ensor was 7.5%. The dete¢tio~ sensitivity of the different sensors had deviations oP 1Q8~ than 15%.
FIG. 2 shows a measuring device utilising a passive sensor, one end of which i~ mirrored whlle the other end i8 connected to a transmitting light wave guide.
Thu~ th- sensor 41 in FIG. 2 has a nonmirrored end 42 and a mlrror-formlng end 43 which causes internal reflection of llght. The transDitting light wave guide is here represented at 44. The nuclear radiation iB applied at 45 and the tissue is represented at 46.
The damping per absorbed nuclear radiation dose unit of the ao senBor 41 is dependent upon the wavelength of the supplied light as ehown in a graph of FIG. 3. In this Figure, the damplng characteristic of a sensor light wave guide and the ~peatral distribution of the radiatlon powers of two LED8 1~
reproduced. If the wavelengths of the lights of the two LEDs i~ eo selected that their central wavelengths 1 and 2 lie in regions of high gradients of the damping or attenuation spectrum, the ratio of the additional damping on pas6age of the light beams through the sensor i8 a measurement of the 202~80 radiation do6e absorbed by the ~ensor light wave guide.
As is apparent from FIG. 2, in the circuit 47 of this apparatus, luminescent diodes 48 and 49, represented as hED 1 and LED 2, generate light of the wavelengths A 1 ~nd A 2, respectively.
These I.EDs ~upply the respective light ~ignals to transmi~slon liqht wave guides or optical fiber~ 50 and 51 which are connected to a Y coupler 52 who6e output optical fiber 53 is connected to one terminal of an X coupler or cross coupler 53.
one termin21 of the X coupler i6 connected, of cour6e, to the transmitting light wave guide 44 while the two other terminals of the cross coupler 53 are light pipes 54 and 55 delivering the respective outputs to detectors 56 and 57 constituting detector6 1 and 2, rQspectively.
The light from two LEDS 48 and 49 are amplitude modulated in the controller 58 for the LEDs and the modulations are sh$fted 180- out of pha6e with one another. The amplitude ratio of` the two signal~ is ~o ~et prior to the irradiation that at the detector 1 represented by the reference numeral 56, a nonmodulated signal is obtained form the sQn60r. The reference detector 2 identified by the reference numeral 57 holds constant the ratio of the alternating component ( ~ P0) of the measuring signal by feedback to the LED8 via the lock in amplifier 59 and the feedback line 60 (see also FIG. 4).
During irradiation of the tissue 46 in the region at which the sensor 41 i8 located by the nuclear radiation represented diagrammatically at 45, the radiation powers Pl and P2 of the 2~24480 llght from the LEDB 48 and 49 will differ ~o that, at the detector 1 represented at 56, a modulated signal will be generated which i~ a measure of the absorbed dose.
Utilizing thQ lock ln amplifier 59 for the detectors 56 and 57, 6mall changes in the radiation rate at a high uniform level can be ~easured 80 that even very small change~ in the damping spectruo of the ~ensor to order~ of magnitude of 10 3 dB can be detected.
With the described measuring device by an appropriate selection of the two LEDs, the cross 6en~itivity of other effects, for example, presaure, the coupllng at the various plug~, temperature, can be minimized.
FIG. 4 sche~atically 6hows the radiant power at the LEDs and the first and second detectors. From this Figure it will be apparent that prior to or without nuclear irradiation at the detector 1, a sub6equently constant or nonmodulated measurement signal i~ obtained while with nuclear irradiation, the amplitude of the alternating component ~ Pi increa~es with increasing dose.
ZO The direct component Pi of the normalized amplitude of the alternating component i~ u6ed to determine the dose. By calibration the sQnsitivity of each individual sensor can be obtained. This can be provided to the user before application.
In FIG. 5, ve have shown a connection between the sensor wave guide 70 and the transmisslve wave guide 82 which avoids the drawbacks of earlier spli¢ing techniques and plug connectors.
--` 2024~80 In practicQs, the uncoated radiation-sen~itive llght waveguide 71 having a diameter of about 120 micrometers is bonded with a biocompatible adheslve 73 in a metal capillary 74 of pure nickel or the 80~20 copper~nickel alloy previously S described, the capillary 74 having an inner diameter of 150 micrometer~ and an outer diametQr of 500 micrometers.
After hardening of the adhesive, both end surfaces 75, 76 are ground and polished. Thereafter tho end surface 75 can be mirrored as shown at 72.
The llght transmissive wave guide has its optlcal fiber 78 ~diametor of the coating equals 250 micromete~s, slmilarly cementod in a capillary 82 with a length of about 10 mllllmetors, ~n lnner diameter of 300 micrometers and an outer dlamotor of 500 miorometers. The end face 77 of thls conatructlon i8 also qround and poll6hed. In FIG. 5 the blocompatlblo adhesivQ cementlng the caplllary 80 to the optical flbor 78 18 representod at 79.
In a thlrd step, the two capillariQs are placed into abuttlng relation6hip within a positioning capillary 81 of the aamQ metal and held in placo without additional optlcal bindlng mat-rlal by ~waging of the further capillary 81.
~A~E OF NUCLEAR RADIA~ION
SPECIFICATION
Field of ~he ~nyç~tion our present invention relates to a method of and to an apparatus for the measurement of the radiation dose or radiation dose rate of nuclear radiation, for example gamma radiation, alpha radiation and beta radiation, In sltu within the tissue of an organi~m which i~ to be sub~ected to that radiation.
B~ckgroun~ o~ ~hÇ I~vçntion In radiation therapy it iB des~rable to know the radiation dose or the radiation dose rate to which a particular organ or tissue location may be subject in the hu~an body or an animal body in the case of human therapy or veterinary therapy, respectively. Radiation therapy of this type may be used to reduce the size of or eliminate tumors or for other medical purposes. By and large, predetermined radiation doses or dose rates are required for specific organs, specific tumors or ~pecific ti6sues.
2024~80 of course, the radiation dose or dose rate can be calculated with respect to each particular location or site, based upon the known rate of incident radiation and ~actor~ such as ab~orption.
However, in many cases, and indeed in most cases it is recognized that an on-line monitoring of the radiation dose or dosa rate actually received at a particular location is desirable.
To the best of our knowledge, it has not been possible to monitor the radiation dose or dose rate during irradiation ln sl tu heretofore.
Ob~ect6 o~ 5he Invention It is, therefore, the principal object of the present invention to provide a method of determining the radiation dose or dose rate ln sltu and during irradiation in living tissue.
Another object is to provide an improved method of monitoring radiation therapy whereby drawbacks in earlier method3 can be avoided and in particular, radiation therapy can be more accurately controlled.
Still another object of the invention i~ to provide an improved sensor enabling the detection and measurement of the dose rate or radiation dose ln sltu within human tissue.
8um~a~y~s~the Inven~lo~
These ob~ects are attained, in accordance with the present invention in a method of measuring radiation dose or dose rate ln sltu within living tis6ue at a particular location subjected to nuclear radiation which comprises the steps of disposing at this lo¢ation a length o~ a ~ensing optical wave ?024480 guide, l.e. an optlcal fiber, manifesting a change in an optical characteristic upon being subjected to nuclear radiation, thereby generating an optical signal, transmitting the optical signal from this 6ensor optical wave guide through a transmission optical wave guide, e.g. an optical fiber or 60-called light pipe, to an electronic circuit capable of analyzing and transducing the optical signal into an electrical signal representing the radiation dose or do~e rate, and di6playing an electrical output representing the radlatlon dose or dose rate in an on-line manner during the irradiatlon of the ti~sue at the site.
According to the invention, the sen~or optical wave guide can be a passive 6ensor, i.e. a sensor in which the radiation induces a change in the optical characteristics of the sensor optical wave guide with respect to transmitted light which can be ~upplied to the sensor, the change in the tran~mitted light caused by the radiation in the sensor represents the optical signal which is transmitted through the transmission optical wave guide and i~ detected and analyzed.
According to a feature of the invention, in the use of a passive 6ensor as described, the incident light transmitted to the sensor can be transmitted through a transmi6sion optical wave guide, i.e. an optical fiber or light pipe and, preferably, the transmis~ion optical wave guide conveying the optical signal to the evaluation, measurement and display circuitry.
According to a feature of the invention, the sensor has a diameter which is less than 0.5 ~ and can be fed to the site or location to be irradiated through a cannula, catheter or other delivery tube which can be ~n~ertQd into 8 body duct such as a portion of the vasculature, respiratory, alimentary and/or intestinal tracts.
It has been found that best results are obtained in the detection of the local effects of nuclear radiation at the tissue site or location when the passive or act$ve light wave guide has a length of 10 to 50 mm.
According to another feature of the invention, one end of the passive or active light wave guide or optical flber con~tituting the sensor is mirrored and only the opposite end is connected with the transmiesion light wave guide.
According to the invention, when a passive sensor light wave guide is used, a coupling member, such as a Y coupler, can be used to deliver the incident radiation to the sensor and to the reference channel of the measurement electronics. When a common transmission light wave guide is used to deliver the incident radiation to the 6ensor and for transmission of the optical signal which i8 effected, a coupler, e.g. an X coupler or a Y
coupler, may be used for feeding the light to the sensor and recovering the optical signal therefrom.
It has been found to be advantageous to provide a passive light wave guide sen~or with light ~ources in the form of two luminescsnt diodes, i.e. light-emitting diodes or LED~, each of which can provide light of a respective wavelength (A 1 and)~2) such that the light of one o~ the diodes is sub~ected to a greater variation by the nuclear radiation than the light from the other diode, but the effect of the transmission light wave guide on both wave~ength~ do not dif~er 6ignific~ntly from one 202~480 177~7 another. The electronic~ can thus be provided to effect a comparison of the light from the two sources and the difference can be used to establish the do~e or dose rate.
The light of both light e~itting diodes can be amplitude s modulated with the modulation of the two diodes phase-shiftQd by 180- and the amplitude ratio of the light outputted by the two diodes can be set before irradiation of the site or location so that a nonmodulatQd measurQment signal is delivered to the circuit.
In a passive wave guide, it should be understood that in solid bodiQs and thus also in liqht wave guides, defect structures, for example, omitted, di~placed or offset latt$ce atoms, exchange of lattice atoms and like point defects, can be generated by particle $rradiation and gamma radiation, i.e.
nuclear radiation or can be effected by such nuclear radlatlon.
8uch nuclear radiation can effect change~ in the electronic band structure by the binding of free electron6 or holes at already-formed defect locations or at lattice defects created by the nuclear radiation These defects formed or lattice defect changes induced by nuclear radiation give rise to significant changes in the damping, refractive lndex or luminescence of a light wave guide through which light can be transmitted.
We will, therefore, distinguish her~in between pa6sive light optical wave guides which operate primarily by an absorption phenomenon or a phenomenon relatad to some other changes in the character of light, and active or scintillating light optical wave guides, ln which the incident radiation causes emission of photons.
.. . ~ . . . . .
2~2~480 177~7 The light wave gulde of the passive ~ensor does not emit of itself light quanta as a consequence of nuclear irradiation.
Its characteristic a6 a sensor i8 based, rather, ùpon the change ln the llght tranemi~sion characterl~tics (damping) induced by nuclear irradiation.
By appropriate doping of the liqht wave guide, it is possible to make the passive sensor selective for the dose range and radiation energy or range to which the sensor is to respond. ~y contrast, the transfer liqht wave guide can be designed not to affect the optical characteristics of transmission therealong and serves only to deliver the optical signal to the detector from the 6ensor.
Since the diameter of the light wave guide is very small, i.e. can be between 10 and 200 micrometers, the sensor, including its guide sleeve or tube, can have a diameter not in oxce~s of 0.5 mm and can be positioned with great aacuracy at the irradiation side in the living tissue utilizing the va~culature or other body pa6sages or by an invasive procedure in which the sensor i8 fed to the site through a tissue-tolerable duct, cannula or catheter.
In the case of radiation which is to be delivered with great accuracy to a particular location and wherein the measurement is desired with the highest possible resolution in terms of location, it is preferred to employ a sensor in the form of a light wave guide having a length of 10 mm to 50 mm.
For a passive sensor, hiqh sensitivity can be achieved through the use of lead-containing light wave guides, i.e.
so-called flint glass fiber~, a~ the sensor light wave guide.
- . - - . . . . . .... .... _ .. ......
~` 2024480 1~74~
In applications ~n which longer sen60rs are to be introduced, for example, germanium-doped glass fiber~ may be preferable.
In the measuring apparatus accordlng to the invention with which the method is carr$ed out, the passive sensor 1B
S eonneeted by a transmis6ion light wave guide with a measuring or analyzlng eircuit, i.e. the electronics of the apparatus.
This circuitry is so constructed that it receives the measurable optical signal on line and processes this signal to determine the dose or dose rate for direct display. The light source whieh iB necessary to "read" the sensor ean be supplied to the latter by the tran6mission light wave guide eonnected to the sensor.
The sensor can bQ connected by one transmission light wave guide with the light 60urcQ and by another transmission wave guide with the analyzing electronic circuitry. The light coming from the source can thus pass through the sensor to the analyzing electronics, the light in the sensor being sub~ected to the damping effect. The circuitry can include a reference ~ource whieh may be coupled to the original source 80 that the optical ~ignal whieh i8 deteeted is ln the form o~ a difference between the original light and the light transmitted through the sensor.
In medieal applications, a8 has previously been indicated, the mea~uring device with its sensor ehould have a diameter which does not exceed 0.5 mm.
It has been found to be especially advantageous to provide a sensor, one end of which i~ formed with a mirror surface and whieh ie internally reflected, and only the other end of whieh Z~4~0 I
i is connected with a transmitting light wave guide. This system is used with a mea~uring device in which a coupling member is connected to the transmitting light wavo guide and with other transmittlng light wave guides communicating with the light source and with the measuring or analyzing electronic circuitry, the transmitting light wave guide between the coupling element and the sensor being used to deliver the light to the sensor and for conducting the optical signal back to the circuitry.
The sensor with the mirrored end reflects the light within the sensor and thus the light traverses the sen~or twice and for a sensor of a given length, can provide twice the damping in response to a given nuclear radiation flux, than a sensor traveroed by the llght only once.
The u~e of two light-emitting diodes ae described allows the wavelengths of the lights of the two diodes to be chosen so that both are in the range in which the nuclear radiation will effect damp$ng within the sensor, thi6 range being wave-length dependent. In this case, the damping caused by the nuclear radiation is accentuated. In the case in which the input wavelengths are amplitude modulated 180' out of phase, a modulated measured signal can be a measure of the radiation effect and thus the radiation dose.
According to another feature of the invention, the sensor light wave guide 18 connected to the transmissive light wave guide in a unique manner, namely, by abutting the two wave guides and retaining them in end to end position by a metal sleeve.
- 2~2~480 177~7 I
We have found that a standard plug connection of the sen~or wave guide cannot always be used when the sensor wave guidQ 1B
to be located within the body of a patient to be sub~ected to the nuclear radiation. The ~tandard plug connection for optical fibers and, consequently, light wave guides, may have a diameter of 7 to 10 mm and a length up to 100 mm which is not amenable to $nsertion into the vasculature of the body or other passagQ~ therein to the site at which the irradiation i8 to take place.
It i8 also known to use a fusion technigue for ~oining glass fiber ends in a fusion ~plicing system. However, even this technique is not suitable where the radiation-6ensitive light wave guide has a high lead content a6 may be the case with the sensor~ of the invention. In fusion splicing technique~ the two glass fiber ends are brought to a temper~ture of about 2000-C in an electric arc which can cause burn off of the lead content of the sensor wave guide.
Temperatures exceeding 500-C will be destructive of the lead content of the ~ensor wave guide 80 that such a splicing technique canno,t be used.
According to the present invention, the uncoated sensor light wave guide i~ cemented by a biocompatible adhesive in a metal capillary or pure nickel or a oopper nickel alloy (80% by weight copper/20% by weight nickel) and the ends of the ~acketed sensor are ground and poli~hed. A mirror is for~ed at one end. The transmissive light wave guide, which is not sensitive to radiation, is likewise bonded in a capillary of the corre~ponding metal and it8 end i8 ground and polished.
202~480 The ground and polished end~ of the sen~or wave guide and the transmissive wave guide, without further optical binding material, are brought into abutting relationship end to end in a positioning metal capillary of the same metal and anchored therein by, for example, swaging the positioning capillary against the metal ~ackets of the 2 wave guides. Alternatively, I
the ends of the wave guides can be ~oined in the manner described and only therea~ter can mirroring of the free end of the sensor wave gulde be effected.
In the use of an active 6ensor, of course, the need for a light source i8 eliminated since the light pulse generated by scintillation upon nuclear irradiation of the sensor is directly a measure oS the dose rate.
~rief Descrip~ion of the Drawing lS The above and other ob~ects, features and advantages of the present invention will become more readily apparent fro~ the following description, reference being made to the acco~panying drawing in which:
FIG. 1 is a block diagram illustrating a sensor according to the invention connected at both ends with a transmitting optical wave guide;
FIG. 2 l~ a view si~ilar to FIG. 1 oS a measuring apparatus utilising a mirrored sensor:
FIG. 3 is a graph howing a damping characteristic of a passive sensor and the spectral distribution oS the radiation . power oS the light source:
FIG. 4 i6 a graph showing the radiation power~ at the light sourcQ and at the detector: and FIG. 5 is a cross sQctional view lllu~trating another feature of the invention.
speclfl~ ÇLi~Lnn FIG. 1 shows a mea~uring apparatuæ having two transmitting light wave guides 11 and 12 connected to opposite ends of a sQnsor light wave guide 13.
The circuitry 14 serves to excite the passive wave guide 13 and i~ connected to the wave guides 11 and 12 via light fiber plug connectors 15, 16, 17, 18. The sensor can be located in living tis6ue represented only diagrammatically at 19 and is in the location of the tissue which is subjected to the radiation field represented by the arrows 20 as a field derived from cobalt 60 irradiation of a patient The circuit 14 comprises a light-emitting diode 21 or some other lumine~cent diode having A wavelength, for example, of 560 nm.
~he output of the light-emitting diode Zl is applied to the transmitting llght wave guide 11 through a Y coupler 22, 10% of the output of which is fed by a light wave guide 23, e.g. at an optical fiber, to the reference channel of the circuitry prov~ded with a detector A transducing the optical signal delivered by the wave guide 23 into an electrical signal.
The balance of the light, i.e. 90% thereof and con~tituting the measuring light is fed through the Y coupler 22 to the transmitting liqht wave gulde 11 ~o that it passes through the 2~24~8~
~ensor 13. The attenu~ted or damplng signal i~ pa~sed via the transmitting optical wave guide 12 to the measuring channel of the circuitry and namely, a detector B ln the form of an optoelectrlcal tran~ducer whlch delivers lt~ signal to the evaluating or analysi6 ¢ircuitry represented at 2~. This cir-cuitry ha~ a display 25 and may include a microprocessor-based computer.
The sensor 13 is a light wave guide of lead-containing glass, e.g. flint glass. The optical damping or attenuation is lncreased when the sensor 18 sub~ected to the radiation field 80 that the nuclear radiation field produced by the cobalt 60urce, for example, produce~ a reduction in the light transmi~slvity of the sensor and thls can be detected at B as a reduction in llght transmissivity as a function of nuclear radiatlon dose. The light ~$gnals are transformed by the detectors A and B into electrical signals which are digitalized and the damping change or attenuation is plotted at 5 on a cathode ray screen or on a paper and ink recorder or the li~e.
The light sourc~ in this embodiment is comprised of the lumlne~cent dlode 21 and the Y coupler 22 while the ~easurement and evaluatlon circuitry comprlses the detector~ A and B of the refQrence and measurement channels and tbe unit 24, 25.
The sen~or can have a dlameter o~ ~ust under 0.5 mm and a length o~ 40 mm. A total doee o~ 60 Gy can be used to irradiate the tlssue. A series of tests have shown that thers i8 no signlflcant change in the detectlon sensitlvity over the total dose range.
. - 2024480 177~7 The detectlon ~en~itlvity wae det-rmlned by calibration measurements in a vater bath to be S x 10 3 Gy with the above-mentioned ~ensor dimeneione.
As a reproducibillty test, a test ser$es with four eeneore s of the same lengtb for a radlation cycle of 24 houre and individual dosages of about 2 Gy under the same te~t conditions were carried out. The maximum deviation of two meaeurements out of seven successive irradiations of the same ~ensor was 7.5%. The dete¢tio~ sensitivity of the different sensors had deviations oP 1Q8~ than 15%.
FIG. 2 shows a measuring device utilising a passive sensor, one end of which i~ mirrored whlle the other end i8 connected to a transmitting light wave guide.
Thu~ th- sensor 41 in FIG. 2 has a nonmirrored end 42 and a mlrror-formlng end 43 which causes internal reflection of llght. The transDitting light wave guide is here represented at 44. The nuclear radiation iB applied at 45 and the tissue is represented at 46.
The damping per absorbed nuclear radiation dose unit of the ao senBor 41 is dependent upon the wavelength of the supplied light as ehown in a graph of FIG. 3. In this Figure, the damplng characteristic of a sensor light wave guide and the ~peatral distribution of the radiatlon powers of two LED8 1~
reproduced. If the wavelengths of the lights of the two LEDs i~ eo selected that their central wavelengths 1 and 2 lie in regions of high gradients of the damping or attenuation spectrum, the ratio of the additional damping on pas6age of the light beams through the sensor i8 a measurement of the 202~80 radiation do6e absorbed by the ~ensor light wave guide.
As is apparent from FIG. 2, in the circuit 47 of this apparatus, luminescent diodes 48 and 49, represented as hED 1 and LED 2, generate light of the wavelengths A 1 ~nd A 2, respectively.
These I.EDs ~upply the respective light ~ignals to transmi~slon liqht wave guides or optical fiber~ 50 and 51 which are connected to a Y coupler 52 who6e output optical fiber 53 is connected to one terminal of an X coupler or cross coupler 53.
one termin21 of the X coupler i6 connected, of cour6e, to the transmitting light wave guide 44 while the two other terminals of the cross coupler 53 are light pipes 54 and 55 delivering the respective outputs to detectors 56 and 57 constituting detector6 1 and 2, rQspectively.
The light from two LEDS 48 and 49 are amplitude modulated in the controller 58 for the LEDs and the modulations are sh$fted 180- out of pha6e with one another. The amplitude ratio of` the two signal~ is ~o ~et prior to the irradiation that at the detector 1 represented by the reference numeral 56, a nonmodulated signal is obtained form the sQn60r. The reference detector 2 identified by the reference numeral 57 holds constant the ratio of the alternating component ( ~ P0) of the measuring signal by feedback to the LED8 via the lock in amplifier 59 and the feedback line 60 (see also FIG. 4).
During irradiation of the tissue 46 in the region at which the sensor 41 i8 located by the nuclear radiation represented diagrammatically at 45, the radiation powers Pl and P2 of the 2~24480 llght from the LEDB 48 and 49 will differ ~o that, at the detector 1 represented at 56, a modulated signal will be generated which i~ a measure of the absorbed dose.
Utilizing thQ lock ln amplifier 59 for the detectors 56 and 57, 6mall changes in the radiation rate at a high uniform level can be ~easured 80 that even very small change~ in the damping spectruo of the ~ensor to order~ of magnitude of 10 3 dB can be detected.
With the described measuring device by an appropriate selection of the two LEDs, the cross 6en~itivity of other effects, for example, presaure, the coupllng at the various plug~, temperature, can be minimized.
FIG. 4 sche~atically 6hows the radiant power at the LEDs and the first and second detectors. From this Figure it will be apparent that prior to or without nuclear irradiation at the detector 1, a sub6equently constant or nonmodulated measurement signal i~ obtained while with nuclear irradiation, the amplitude of the alternating component ~ Pi increa~es with increasing dose.
ZO The direct component Pi of the normalized amplitude of the alternating component i~ u6ed to determine the dose. By calibration the sQnsitivity of each individual sensor can be obtained. This can be provided to the user before application.
In FIG. 5, ve have shown a connection between the sensor wave guide 70 and the transmisslve wave guide 82 which avoids the drawbacks of earlier spli¢ing techniques and plug connectors.
--` 2024~80 In practicQs, the uncoated radiation-sen~itive llght waveguide 71 having a diameter of about 120 micrometers is bonded with a biocompatible adheslve 73 in a metal capillary 74 of pure nickel or the 80~20 copper~nickel alloy previously S described, the capillary 74 having an inner diameter of 150 micrometer~ and an outer diametQr of 500 micrometers.
After hardening of the adhesive, both end surfaces 75, 76 are ground and polished. Thereafter tho end surface 75 can be mirrored as shown at 72.
The llght transmissive wave guide has its optlcal fiber 78 ~diametor of the coating equals 250 micromete~s, slmilarly cementod in a capillary 82 with a length of about 10 mllllmetors, ~n lnner diameter of 300 micrometers and an outer dlamotor of 500 miorometers. The end face 77 of thls conatructlon i8 also qround and poll6hed. In FIG. 5 the blocompatlblo adhesivQ cementlng the caplllary 80 to the optical flbor 78 18 representod at 79.
In a thlrd step, the two capillariQs are placed into abuttlng relation6hip within a positioning capillary 81 of the aamQ metal and held in placo without additional optlcal bindlng mat-rlal by ~waging of the further capillary 81.
Claims (17)
1. A method of measuring the nuclear radiation dose or the dose rate of nuclear radiation in living tissue, comprising the steps of:
(a) positioning at a site in living tissue to be subjected to nuclear irradiation a length of 10 to 50 mm of a light wave guide forming a sensor;
(b) subjecting said tissue at said location to nuclear irradiation thereby irradiating with said nuclear irradiation said sensor and generating therein an optical signal representing said dose or dose rate;
(c) communicating said optical signal as it is formed in said sensor to a location remote from said site by a transmissive light wave guide;
(d) detecting said optical signal at said location and transducing said optical signal into an electronic signal; and (e) analyzing said electronic signal to provide an output representing on-line a measurement of said dose or said dose rate.
(a) positioning at a site in living tissue to be subjected to nuclear irradiation a length of 10 to 50 mm of a light wave guide forming a sensor;
(b) subjecting said tissue at said location to nuclear irradiation thereby irradiating with said nuclear irradiation said sensor and generating therein an optical signal representing said dose or dose rate;
(c) communicating said optical signal as it is formed in said sensor to a location remote from said site by a transmissive light wave guide;
(d) detecting said optical signal at said location and transducing said optical signal into an electronic signal; and (e) analyzing said electronic signal to provide an output representing on-line a measurement of said dose or said dose rate.
2. The method defined in claim 1, further comprising the step of passing through said sensor a light beam which is modified in said sensor by nuclear irradiation to form said optical sensor, said light beam being fed to said optical sensor through a transmissive light wave guide.
3. The method defined in claim 1 wherein said sensor has a diameter of not more 0.5 mm and is disposed at said site by feeding it through a tissue-tolerable passage to said site.
4. An apparatus for measuring the nuclear radiation dose or the dose rate of nuclear radiation in living tissue which comprises:
a light wave guide responsive to nuclear irradiation and forming a sensor;
means for positioning said sensor at a site in living tissue to be subjected to nuclear irradiation, thereby generating in said sensor an optical signal representing said dose or dose rate;
a transmissive light wave guide communicating said optical signal as it is formed in said sensor to a location remote from said site;
means at said location connecting to said transmissive light wave guide for detecting said optical signal and transducing said optical signal into an electronic signal:
means connected to said detecting means for analyzing said electronic signal to provide an on-line output representing a measurement of said dose or said dose rate; and a source of a light beam to be delivered to said sensor for producing said optical signal by nuclear irradiation modification of said light beam, an end of said sensor is mirrored and only on opposite end of said sensor connected with a transmissive light wave guide.
a light wave guide responsive to nuclear irradiation and forming a sensor;
means for positioning said sensor at a site in living tissue to be subjected to nuclear irradiation, thereby generating in said sensor an optical signal representing said dose or dose rate;
a transmissive light wave guide communicating said optical signal as it is formed in said sensor to a location remote from said site;
means at said location connecting to said transmissive light wave guide for detecting said optical signal and transducing said optical signal into an electronic signal:
means connected to said detecting means for analyzing said electronic signal to provide an on-line output representing a measurement of said dose or said dose rate; and a source of a light beam to be delivered to said sensor for producing said optical signal by nuclear irradiation modification of said light beam, an end of said sensor is mirrored and only on opposite end of said sensor connected with a transmissive light wave guide.
5. The apparatus defined in claim 4 wherein said source is connected to said sensor by a transmissive light wave guide.
6. The apparatus defined in claim 5 wherein said transmissive light wave guide delivering said light beam to said sensor is the same light wave guide connecting said sensor to said detector.
7. The apparatus defined in claim 6 wherein said sensor has a diameter of less than 0.5 mm.
8. The apparatus defined in claim 6 wherein said source is connected by a transmissive light wave guide to a Y coupler having one output connected by a transmissive light wave guide to said sensor and another output connected to a detector of a reference channel for said means for analyzing.
9. The apparatus defined in claim 6, further comprising a coupler between said source and said sensor and connected to said transmissive light wave guide whereby the same light wave guide delivers said light beam to said sensor and recovers said optical signal from said sensor.
10. The apparatus defined in claim 6 wherein said source comprises two light-emitting diodes each generating a light beam of a different wavelength, the light beam from one of said diodes having a relatively greater intensivity change upon the subjection of the sensor receiving same to nuclear radiation than the light beam from the other of said diodes, said means for analyzing comparing light signals from said light beams.
11. The apparatus defined in claim 10, further comprising means for amplitude modulating said light beams with 180° phase shift between them, with the amplitude modulation of said light beams producing in the absence or irradiation of said sensor prior to such irradiation a nonmodulated measurement signal.
12. The apparatus defined in claim 4 wherein said light wave guide forming said sensor is connected to said transmiss-ive light wave guide by a coupling retaining said wave guides in end-to-end abutting relationship and comprising a metal capillary adhesively bonded to each of said wave guides, and a positioning metal capillary receiving the metal capillaries bonded to said wave guides.
13. A method of making a sensor for the detection of radiation in situ within the body of an arganism to be subjected to nuclear radiation, comprising the steps of:
a) adhesively bonding a radiation-sensitive light wave guide in a metal capillary;
b) grinding and polishing opposite ends of said metal capillary & said radiation sensitive light wave guide received therein to provide polished opposite ends thereon;
c) forming one of said opposite ends as a mirror;
d) bonding adhesively a light transmissive wave guide insensitive to said nuclear radiation in a metal capillary over a portion of a free end thereof;
e) grinding and polishing said free end and the metal capillary bonded to said light transmissive wave guide: and f) inserting said free end and the metal capillary bonded to said light transmissive wave guide and the other end of said radiation sensitive wave guide and the metal capillary bonded thereto into a positioning capillary into end-to-end abutting relationship and arching same in said abutting relationship to couple said light transmissive wave guide to said sensitive wave guide.
a) adhesively bonding a radiation-sensitive light wave guide in a metal capillary;
b) grinding and polishing opposite ends of said metal capillary & said radiation sensitive light wave guide received therein to provide polished opposite ends thereon;
c) forming one of said opposite ends as a mirror;
d) bonding adhesively a light transmissive wave guide insensitive to said nuclear radiation in a metal capillary over a portion of a free end thereof;
e) grinding and polishing said free end and the metal capillary bonded to said light transmissive wave guide: and f) inserting said free end and the metal capillary bonded to said light transmissive wave guide and the other end of said radiation sensitive wave guide and the metal capillary bonded thereto into a positioning capillary into end-to-end abutting relationship and arching same in said abutting relationship to couple said light transmissive wave guide to said sensitive wave guide.
14. The method defined in claim 13 wherein said wave guides are bonded to the respective metal capillaries by biocompatible adhesives.
15. The method defined in claim 14 which comprises forming said metal capillaries of pure nickel or 80/20 copper/nickel alloy.
16. The method defined in claim 15 wherein said one of said ends is mirrored prior to introducing said other of said ends into said positioning capillary.
17. The method defined in claim 15 wherein said one of said ends is mirrored subsequent to insertion of said other of said ends into said positioning capillary.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3929294.0 | 1989-09-04 | ||
| DE19893929294 DE3929294A1 (en) | 1989-09-04 | 1989-09-04 | METHOD AND MEASURING DEVICE FOR MEASURING THE DOSAGE OR DOSAGE PERFORMANCE OF CORE RADIATION |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2024480A1 true CA2024480A1 (en) | 1991-03-05 |
Family
ID=6388574
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2024480 Abandoned CA2024480A1 (en) | 1989-09-04 | 1990-08-31 | Method of and apparatus for measuring the dose or dose rate of nuclear radiation |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0416493A3 (en) |
| JP (1) | JPH0399292A (en) |
| CA (1) | CA2024480A1 (en) |
| DE (1) | DE3929294A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7399977B2 (en) | 2004-07-23 | 2008-07-15 | University Health Network | Apparatus and method for determining radiation dose |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19503647C2 (en) * | 1995-02-06 | 1999-12-16 | Forschungszentrum Juelich Gmbh | Measuring device for in-vivo and on-line determination of the tissue-equivalent dose in radiation therapy |
| DE19528096C2 (en) * | 1995-08-01 | 1999-01-07 | Forschungszentrum Juelich Gmbh | Method and device for measuring the penetration depth of radiation |
| DE19545060C1 (en) * | 1995-12-02 | 1997-04-03 | Forschungszentrum Juelich Gmbh | Fibre-optic sensor for tissue-equivalent radiation dosimetry |
| DE19646267C1 (en) * | 1996-11-09 | 1997-11-20 | Forschungszentrum Juelich Gmbh | Radiation dosage measuring sensor |
| DE10162985B4 (en) * | 2001-12-20 | 2006-05-24 | Siemens Ag | Terminal with a device for the optical reproduction of information |
| DE10342497A1 (en) * | 2003-09-12 | 2005-04-21 | Shaft Form Engineering Gmbh | Connection system for a shaft to a joint |
| US20120224167A1 (en) * | 2007-07-18 | 2012-09-06 | Honeywell International, Inc. | Apparatus and method for chemical, biological and radiological agent sensing |
| KR101500786B1 (en) | 2007-09-11 | 2015-03-09 | 베헤르 게엠베하 운트 콤파니 카게 | Heat exchanger, particularly for a motor vehicle |
| EP2591380A4 (en) | 2010-07-07 | 2018-03-07 | University Health Network | Fiber optic radiochromic dosimeter probe and method to make the same |
| CN102520433A (en) * | 2011-12-23 | 2012-06-27 | 北京航空航天大学 | All-optical-fiber on-line radiation dose measuring system |
| JP6681302B2 (en) * | 2016-09-01 | 2020-04-15 | 株式会社日立製作所 | Radiation monitor and radiation monitor analysis method |
| CN111505695B (en) * | 2020-04-26 | 2021-12-31 | 北京光衡科技有限公司 | Radiation dosimeter based on doped fiber self-excitation radiation |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2231017A1 (en) * | 1973-05-21 | 1974-12-20 | Robillard Jean | Liq. scintillator for intravenal beta radiation measurements - using optic fibre with plastic coating to form cavity for scintillator solute |
| DE3234900A1 (en) * | 1982-09-21 | 1984-03-22 | Siemens Ag | FIBER OPTICAL SENSOR |
| JPS59228183A (en) * | 1983-06-10 | 1984-12-21 | Dainichi Nippon Cables Ltd | Radiation sensor |
| GB2200984B (en) * | 1986-12-16 | 1990-11-07 | Optical Data Communications Lt | Fibre optic ionising radiation detector |
| US4788436A (en) * | 1986-12-24 | 1988-11-29 | Walter Koechner | Radiation sensitive optical fiber and detector |
-
1989
- 1989-09-04 DE DE19893929294 patent/DE3929294A1/en not_active Withdrawn
-
1990
- 1990-08-31 CA CA 2024480 patent/CA2024480A1/en not_active Abandoned
- 1990-09-03 JP JP23073990A patent/JPH0399292A/en active Pending
- 1990-09-03 EP EP19900116837 patent/EP0416493A3/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7399977B2 (en) | 2004-07-23 | 2008-07-15 | University Health Network | Apparatus and method for determining radiation dose |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0416493A2 (en) | 1991-03-13 |
| EP0416493A3 (en) | 1991-09-11 |
| JPH0399292A (en) | 1991-04-24 |
| DE3929294A1 (en) | 1991-03-14 |
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