Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
  • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
  • G01T1/16—Measuring radiation intensity
  • G01T1/161—Applications in the field of nuclear medicine, e.g. in vivo counting
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/40—Arrangements for generating radiation specially adapted for radiation diagnosis
  • A61B6/4057—Arrangements for generating radiation specially adapted for radiation diagnosis by using radiation sources located in the interior of the body
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/42—Arrangements for detecting radiation specially adapted for radiation diagnosis
  • A61B6/4208—Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a particular type of detector
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/42—Arrangements for detecting radiation specially adapted for radiation diagnosis
  • A61B6/4208—Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a particular type of detector
  • A61B6/4258—Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a particular type of detector for detecting non x-ray radiation, e.g. gamma radiation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
  • A61B6/5205—Devices using data or image processing specially adapted for radiation diagnosis involving processing of raw data to produce diagnostic data
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/06—Diaphragms
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/44—Constructional features of apparatus for radiation diagnosis
  • A61B6/4423—Constructional features of apparatus for radiation diagnosis related to hygiene or sterilisation

Definitions

• the invention is referred to a scintigraphic probe, particularly an endocavitary scintigraphic probe being used for a radioactivity-guided search of tissue anomalies like tumour masses with various sizes and nature.
• a scintigraphic probe particularly an endocavitary scintigraphic probe being used for a radioactivity-guided search of tissue anomalies like tumour masses with various sizes and nature.
• Such instrument is offered to the surgeon for a precise and selective localization of tumours in patients preliminarily treated with a radioactive substance called radiopharmaceutical.
• the probe is directly used on the inner tissue of an internal organ of the patient, beforehand incised by the surgeon for the insertion thereof.
• the detection of the anomalous mass is carried out through the detection of an ionizing radiation, X-rays or gamma rays, emitted by an accumulation of said substance into the examined tissue.
• Said radiation is emitted, directly or indirectly, by the decay of radioisotopes used for the radiopharmaceutical marking. Therefore, the identification of the tumour site occurs by an analysis of the radioisotope distribution.
• the used radiopharmaceutical is accumulated into the tumour mass, so acting as a high emission site, easily detectable by a scintigraphic probe.
• a ionizing photon when a ionizing photon interacts with a scintillating crystal, it determines the light emission from the crystal itself.
• a photomultiplier converts the light signal from the crystal into a measurable electric signal.
• the number of photons detected in the time unit is proportional to the concentration of radioisotope into the instrument measurement cone.
• the identification of high emission sites is carried out through the comparison of the computations executed in real time at the interesting region. The surgeon is informed on the activity of the investigated site both by the direct display of the detected photon number and by a sound indicator frequency modulated proportionally according to the level of the computing itself.
• endocavitary probes are known in the market, for the detection of photons emitted by radionuclides injected into the patient's body. Often, they are provided with long wires for the connection to the central processing unit and for the electric supply of the electronics in the probe. The presence of such wiring implies an apparent limit for the handiness of the probe. Moreover, the current sterilisation techniques involve frequent working anomalies, just because of the connection wire.
• probes have architectures based on the coupling of photodiodes with semiconductor detectors, like Cd-Te or Cd-Zn-Te or inorganic crystal as well, like Cs-I(TI).
• semiconductor detectors like Cd-Te or Cd-Zn-Te or inorganic crystal as well, like Cs-I(TI).
• the use of semiconductor detectors assures a good spatial resolution to the instrument, but poor detection sensitivity.
• devices are known bases on the scintillating crystal-photomultiplier coupling, having instead simple gamma detectors, apt only to detect the gamma radiation and to amplify the electric signal to the photomultiplier anode.
• the signal processing is the operated by appropriate processing units, outside the device.
• the technical problem underlying the present invention is to obviate to the drawbacks mentioned with reference to the known art, providing the surgeon with a new instrument, apt to remarkably improve the quality and the effectiveness of the surgical operation.
• a scintigraphic probe as defined in claim 1.
• This probe does not require the presence of any wiring and therefore it has an outstanding handiness.
• Figure 1 is a side view (a), a top plan view (b) and an axonometric view (c) showing the external casing of a scintigraphic probe according to the invention.
• Figure 2 shows an axonometric view illustrating two sections composing the body of the probe of Figure 1 ;
• Figure 3 shows an exploded axonometric view of the probe of Figure 1 , minutely illustrating the parts composing the probe body;
• Figure 4 shows a sectioned axonometric view illustrating the arrangement of internal components inside the probe body of Figure 1 ;
• Figure 5 shows an exploded axonometric view of the parts composing a removable supply module of the probe of Figure 1 ;
• Figure 6 shows a detailed axonometric view of the hardware of the probe of Figure 1 ;
• Figure 7 shows a block diagram illustrating the internal processing of the signal drawn at the output of a photomultiplier of the probe of Figure 1 ;
• Figure ⁇ illustrates the operation principle of the variable collimation applied to the probe of Figure 1.
• a scintigraphic probe has an external case provided with an ergonomic and peculiar shape, elongated according to a main axis and defined by a revolution surface related to said axis, with a cylindrical end section with a reduced diameter, ending with a distal end, and a probe body easily graspable, with a central swelling.
• the probe body (a) is detachable from a removable supply module (b), which can be fastened to said body with a snap device.
• the probe body comprises a container of the electronics 1 to which a supply module is connected, provided with a connection element 2. It comprises further a joint ring 3 linking the container of the electronics 1 with the remaining portion of the probe, allowing the rotation of the front portion of the probe with respect to the back portion, thereby assuring the variation of collimation.
• the probe At a narrowed portion of the probe, it comprises a container 4 of the scintillating crystal, of the photomultiplier, of the voltage divider and of the preamplifier. It represents the mobile portion, allowing the variation of collimation.
• joint member 5, 6 are provided, connected, to one part and to the other, to said end section moving, protected by the external case 8 thereof, with respect to the inner patient's organs.
• suitable grooves are formed, representing one of the fundamental elements of the variable collimation mechanism.
• a collimator 7 in tungsten alloy, operating as a screen, is housed in a case 8 at the end of the container 4, in close contact to the bottom thereof.
• the joint members 5, 6 have in detail helicoidal grooves formed on the inner wall thereof, these grooves make possible the variation of the collimation substantially acting as cam profiles for guiding the movement of the container and of the content thereof, i.e. the mobile portion of the probe, protected by the case 8.
• the container 4 has pins (not shown) in engagement into said grooves of the joint members 5, 6, just to be able to freely rotate with respect to the ring ⁇ and to the case ⁇ .
• a scintillating crystal 9 which can be of the PbWO 4 type, positioned at the distal end of the probe; a photomultiplier 10, completed with voltage divider, placed immediately close to the crystal 9 in the reduced diameter section; an electronic board constituting means for the management and the processing of the signal produced by the photomultiplier and which is housed in the central portion of the probe body; and a high voltage module 12 for the supply of the photomultiplier.
• Figure 5 shows in detail the constituting portions of the removable supply module, particularly a battery case 13 hosting a battery 14 and which, at the bottom thereof, has a release latch flat member 15 provided with holes cooperating with hooks of the probe body.
• accumulators of different typologies, i.e. accumulators Ni-Cd (Nickel-Cadmium), Ni-MH (Nickel-metallic hydride), Li-ion (Lithium-ion) and Li-Po (Lithium-Polymer).
• an accumulator Li-ion is used.
• Figure 6 instead shows in detail the various components of the above mentioned electronic board 11. It comprises, on a board support, a pre-amplifying unit A, an amplifying unit B, an analogical-digital converter C, a signal processing unit D and a data wireless transmission unit E.
• These components hence embody means for processing the signals from the photomultiplier, converting them in data to be transmitted to a suitable remote processing unit, external to the case; and wireless connection means between said means for processing the signals and said remote processing unit.
• Figure 7 shows in detail the internal processing method of the signal collected at the anode of the photomultiplier inside the previously described board.
• An integrated component A is used for pre-amplifying the output signal from the photomultiplier, which is then amplified by the subsequent integrated component B connected to the module A.
• the signal is converted by the integrated component C from analogical to digital.
• the used sampling is of the variable kind (sample/hold) and it is controlled by a microcontroller system, indicated as module D, where a discrimination function is present, apt to eliminate all the input analogical signals not exceeding a certain threshold value.
• a signal processing unit composed by a micro controller D with a micro software loaded in a flash memory able to carry out time-variable integration functions, (Fast Fourier Transformations) and to compare in real time samples coming from said module C with those loaded in the memory, processes digital signals as result of such a conversion.
• the unit E arranged for the wireless transmission of data appropriately transmits the data according to a software which will be detailed in the following.
• the above described wireless transmission means has a transmission bandwidth comprised in the ISM 2.4 GHz band, and modulations GFSK (Gaussian shaped Frequency Shift Keying), DPSK (Differential Phase Shift Keying) or DQPSK (Differential Quadrature Phase Shift Keying) to an external calculator, provided with a suitable software for the management of the received data.
• Figure 8 shows in its entirety the operation principle of the variable collimation. With reference to Figure 8a, it is illustrated how the variable collimation be obtained thank to a mechanical-kind actuation.
• the surgeon rotates the front portion of the probe and, according to the entity of the rotation, he achieve a different positioning of the scintillating crystal with respect to the collimator.
• variable collimation system for the variation of the measurement cone of the probe itself is composed by a rotating mechanism, so as to vary the relative position of the scintillating crystal (mobile portion of the mechanism) and of the internal collimator (fixed portion of the mechanism), to render maximum the spatial resolution of the probe itself, preferably achieved by moving the scintillating crystal with respect to the collimator, so as to vary the half width of the measurement cone between 20° and 90°.
• any scintillating crystal appropriately used for the detection of radiations can be used.
• a crystal capable to reveal gamma radiations will be preferred, e.g.
• the inorganic scintillating crystals belonging to the class of the inorganic scintillating crystals (NaITI, CsI :TI, CaF 2 :Eu, Bi 4 GeO 4 , BaF 2 , Y 3 AI 5 Oi 2 Oe, YAIO 3 :Ce, Gd 2 Si0 5 :Ce, CdWO 4 , PbWO 4 , Nb(WO 4 ) 2 , Lu 3 AI 5 O 7 , Lu 2 Si0 5 :Ce, ZnWO 4 ), preferably of the kind PbWO 4 .
• the photomultiplier which can be used: any photomultiplier used for the detection of radiations emitted by the crystal can be used.
• bialkali, multialkali, Sb-Cs and Ga-As photocathode photomultipliers are appropriate.
• a bialkali photocathode photomultiplier is used.
• the removable supply module of the device can be fastened to and removed from the probe body through the operation of a suitable spring system.
• the accumulator is connected to the supply circuit through suitable electrodes, assuring the electrical connection.
• a clear advantage due to the use of the above described probe is constituted by the processing inside the probe of the signal collected at the anode of the photomultiplier through the use of an innovative electronics.
• the signal collected at the anode of the photomultiplier is first amplified up to a level so as to allow the analogical-to-digital conversion thereof. Then, the digitalized signal is processed by a suitable microcontroller, which first compares the received signal with the calibration values pre-charged in a memory and then it carries out various integration operations variable in time and of Fast Fourier Trasformate (FFT). The processed signal is sent to a wireless transmission module, providing to the sending thereof.
• FFT Fast Fourier Trasformate
• the probe is provided with an automatic calibration system through which a clear improvement of the instrument functionality is achieved, advantaging the quality of the operation.
• the data processed and transmitted by the probe are managed through the use o fan appropriately developed software, compatible with any kind of operation system, both at 32 and at 64 bit.
• the software allowing the visualization of the signal processed by the invention is composed by the following functional modules and it has scalable features, so as to allow the introduction of further additional modules according to a astandard. It realizes:
• a battery-charge state module and management of diagnostic alarms of the probe • A user interface with time diagram and multi-digit visualization of the real time detected signal and of the computing-by-second, with the possibility of varying, according to the kind of surgical intervention, the integration pitch along the time; • A functional module for the acquisition and real time visualization of the energetic spectrum and the dynamic adjustment of the energetic windows and of the number of counting per second (counting-rate) on a programmable time interval, to simultaneously visualize the spectrum and the position of the energetic windows and thereby obtaining an absolutely precise calibration;
• the internal processing of the signal allows to the probe of transmitting, through wireless connection, easily manageable data from any kind of calculator provided with the above described software, to an external remote processing unit. It can be realized by any kind of calculator and operative system, allowing to limit at the minimum the non-use periods.
• the shape of the probe is distinguished by an innovative and functional design, apt to assure to the surgeon the maximum comfort and handiness.
• the ergonomic profile is particularly important, since the good use of the device is bond to the handiness thereof.
• the probe has a shielding system of the scintillating crystal, particularly composed by a tungsten (W) alloy shield, apt to limit at the minimum the negative effects of the background radiation.
• a shielding system of the scintillating crystal particularly composed by a tungsten (W) alloy shield, apt to limit at the minimum the negative effects of the background radiation.
• the shield mounted inside the invention assures a reliable shielding for photons up to 170 KeV.
• the use of the probe with more energetic radioisotopes can be carried out with the coupling to a series of additional external collimators, or with a collimator of greater thickness.
• the internal variable collimation system is able to assure a full adaptability of the device to any of the applications to which it has been designed.
• the way through which the variation of collimation is carried out is particularly innovative: by the rotation of a portion of the probe is in fact possible to vary the relative position between scintillating crystal (mobile portion) and internal collimator (fixed portion), to optimize the spatial resolution of the instrument.
• any angle can be used and realized.
• a preferred embodiment of the invention uses half-width angles of the measurement cone within 20° and 90°.
• materials which can be used any biocompatible metal, alloy or other, used in biomedical devices is admitted.
• the components are made of Titanium, Steel and PTFE (Polytetrafluoroethylene).
• the geometrical dimensions can vary within the following ranges: length 20-60 cm, minimum and maximum diameter 1-7 cm. In the present embodiment, the dimension are: length about 30 cm, minimum diameter 1 ,5 cm, maximum diameter about 4 cm.
• the front end of the probe (reference numeral 8 in Figure 3) can be inclined of an angle comprised between 0° and 90°, preferably 0°.
• the probe is specifically designed for all the applications in radioguided surgery, based on the administering of radiopharmaceuticals marked with 99m Tc, 125 I, 111 In and 18 F.
• the applicability of the device is coupled with the currently used pharmaceuticals.
• the probe can be appropriately developed for detecting gamma radiations with an energy within 30 KeV and 1 MeV.
• the probe may be associated to any commercial calculator, although provided with the related management software.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Medical Informatics (AREA)
• Physics & Mathematics (AREA)
• Biomedical Technology (AREA)
• General Health & Medical Sciences (AREA)
• High Energy & Nuclear Physics (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Optics & Photonics (AREA)
• Molecular Biology (AREA)
• Heart & Thoracic Surgery (AREA)
• Radiology & Medical Imaging (AREA)
• Pathology (AREA)
• Surgery (AREA)
• Animal Behavior & Ethology (AREA)
• Biophysics (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Computer Vision & Pattern Recognition (AREA)
• General Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Measurement Of Radiation (AREA)
• Arrangements For Transmission Of Measured Signals (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=40315815

Family Applications (1)

Country Status (3)

Families Citing this family (2)

Family Cites Families (5)

• 2007
  • 2007-12-10 IT ITRM20070633 patent/ITRM20070633A1/it unknown
• 2008
  • 2008-12-10 EP EP08859900A patent/EP2235564A2/en not_active Withdrawn
  • 2008-12-10 WO PCT/IB2008/055207 patent/WO2009074959A2/en active Application Filing

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events