RADIOCAPSULE FOR REGISTERING IONIZING RADIATION IN THE CAVITIES OF HUMAN BODIES
United States Patent 3690309
A radiocapsule for registration of ionizing radiation in the cavities of human body, comprising a detector to register ionizing particles in the cavities of human body and to modulate r.f. signals of an inverter of a d.c. voltage into an a.c. sine voltage at the moment when ionizing particles are being registered, said inverter having a piezo-electric transformer.
US Patent References:
PASSIVE TELEMETRY SYSTEM
Temps et al. - April 1971 - 3576554
Electrical conversion apparatus
Rosen - March 1961 - 2975354
TELEMETER ADAPTABLE FOR IMPLANTING IN AN ANIMAL
Fryer - July 1969 - 3453546
BEHAVIORAL SUPERVISION SYSTEM WITH WRIST CARRIED TRANSCEIVER
Schwitzgebel et al. - November 1969 - 3478344
BIOMEDICAL RADIATION DETECTING PROBE
Webb - February 1969 - 3427454
PASSIVE TELEMETRY SYSTEM
Temps et al. - April 1971 - 3576554
Electrical conversion apparatus
Rosen - March 1961 - 2975354
TELEMETER ADAPTABLE FOR IMPLANTING IN AN ANIMAL
Fryer - July 1969 - 3453546
BEHAVIORAL SUPERVISION SYSTEM WITH WRIST CARRIED TRANSCEIVER
Schwitzgebel et al. - November 1969 - 3478344
BIOMEDICAL RADIATION DETECTING PROBE
Webb - February 1969 - 3427454
Inventors:
Viktor, Mikhailovich Pluzhnikov
Korpus, Kv 32 6. (Moscow, Soviet Union)
Karl Davidovich, Kalantarov Ulitsa Serafimovicha (2, kv.)
469 (Moscow, Soviet Union)
Jury Yakovlevich, Gugnin Timiryazevskaya Ulitsa
Kv, 108 (Moscow, Soviet Union)
Valentin Sergeevich, Semenov Ulitsa Garibaldi
Korpus, Kv 79 1. (Moscow, Soviet Union)
Valentina Vasilievna, Zelenina
Korpus, Kv 15 9. (Moscow, Soviet Union)
Albert Ivanovich, Filatov Nagornaya Ulitsa 64 (2a, kv.)
61 (Moscow, Soviet Union)
Korpus, Kv 32 6. (Moscow, Soviet Union)
Karl Davidovich, Kalantarov Ulitsa Serafimovicha (2, kv.)
469 (Moscow, Soviet Union)
Jury Yakovlevich, Gugnin Timiryazevskaya Ulitsa
Kv, 108 (Moscow, Soviet Union)
Valentin Sergeevich, Semenov Ulitsa Garibaldi
Korpus, Kv 79 1. (Moscow, Soviet Union)
Valentina Vasilievna, Zelenina
Korpus, Kv 15 9. (Moscow, Soviet Union)
Albert Ivanovich, Filatov Nagornaya Ulitsa 64 (2a, kv.)
61 (Moscow, Soviet Union)
Application Number:
05/061370
Publication Date:
09/12/1972
Filing Date:
08/05/1970
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
331/155, 310/318, 331/65, 310/311, 600/436
International Classes:
A61B5/07; G01T1/18; G01T1/00; A61B5/07
Field of Search:
128/2A,2P,2.1A,2.1R 331/155,158,163,65 310/8,9
US Patent References:
Other References:
Intern. Conference Medical Electronics, 1959, pp. 300-306.
Primary Examiner:
Kyle, Howell L.
Attorney, Agent or Firm:
Waters, Roditi, Schwartz & Nissen
Claims:
1. A radiocapsule for registering ionizing radiation in the cavities of a human body, comprising a detector means adapted to register ionizing particles in said cavities of the human body; an r.f. oscillator means simultaneously producing a voltage for supplying to said detector and radio signals modulated by said detector at the moment when each of the ionizing particles is being registered, said r.f. oscillator means including an r.f. emitting means and further comprising an inverter for a d.c. voltage into an a.c. sine voltage, said inverter having an input electrically connected with said detector and an output generating modulated radio signals; said inverter including a transistor having an input providing the modulating input of said inverter; a piezoelectric transformer means connected to said r.f. oscillator, said piezo-electric transformer means having an input connected to the output of said transistor and said output being electrically connected with the input of said transistor and with the detector so as to ensure amplitude modulation of the radio signals; and a d.c. voltage source means.
Description:
The present invention relates generally to radiotelemetric systems for examination of the cavities of human body and more specifically, to radiocapsules for registration of ionizing radiation in the cavities of human body, with the radiocapsules serving as transmitters in radiotelemetric systems.
There exist in the art nowadays radiocapsules for registration of ionizing radiation in the cavities of human body, comprising a detector which registers ionizing particles in the cavities of human body and modulates r.f. signals generated by an oscillator at the moment the ionizing particles are being registered.
In the aforementioned radiocapsules an r.f. oscillator is formed as a l.f. relaxation inverter of a d.c. voltage into an a.c. pulsing voltage, and with the inverter incorporating a multicircuit transformer. At the moment the ionizing particles are being registered, the detector causes the relaxation frequency of the inverter to vary, thereby providing frequency-pulse modulation of the r.f. signals being emitted.
Provision of a multicircuit transformer possessing a large number of turns in the prior-art radiocapsules adversely affects their reliability, renders them too complicated to make and inadequately small in size.
Furthermore, provision of the r.f. oscillator as a relaxation inverter featuring pulse frequency modulation, is responsible for the dissipated power of r.f. signals which, in turn, affects in a detrimental manner the jamming invulnerability of the radio emission, impedes the obtaining of the required time resolution of the ionizing emission registration and complicates the entire construction of a radiotelemetric system.
It is an object of the present invention to provide a radiocapsule for registering ionizing radiation in the cavities of human body that will ensure an increased reliability and a higher quality of the registration of ionizing radiation.
It is another object of the present invention to provide a radiocapsule for registering ionizing radiation in the cavities of human body which has a small size and an improved production technology therefore.
According to the above-stated objects in a radiocapsule for registration of ionizing radiation in the cavities of human body, comprising a detector which is to register ionizing particles in the cavities of human body and to modulate r.f. signals generated by an oscillator at the moment the ionizing particles are being registered,, the r.f. oscillator in accordance with the invention is made as an inverter of a d.c. voltage into an a.c. sine voltage and comprises a piezo-electric transformer electrically connected to the detector so as to ensure an amplitude modulation of the r.f. signals generated.
Such a construction of the herein-disclosed radiocapsule renders it more reliable, improved its production technology, reduces its size and simplifies the construction of a radiotelemetric system as a whole.
The nature of the present invention is explained in the following disclosure of an exemplary embodiment thereof in conjunction with the accompanying drawing, wherein a circuit schematic of the herein-proposed radiocapsule is represented.
Referring now to the drawing, the radiocapsule for registration of ionizing radiation in the cavities of human body, according to the invention comprises a detector which is adapted to register ionizing particles in the cavities of human body (not shown in the drawing), said detector including a Geigen Muller counter 1 which modulates the r.f. signals generated by an oscillator 2 at the moment when ionizing particles are being registered, as well as comprising a rectifier 3 and a d.c. low-voltage source 4 to supply power to the oscillator 2.
The r.f. oscillator 2 is made as an r.f. inverter for a d.c. voltage into an a.c. sine voltage, with the inverter comprising a transistor 5, a capacitor 6, an inductance 7, a resistor 8 and a piezo-electric transformer 9 which is electrically coupled through a rectifier 3 to the G-M counter 1 so as to ensure an amplitude modulation of the r.f. signals generated.
The piezo-electric transformer 9 can be of any arbitrary size and configuration. In the specific and preferred embodiment of the radiocapsule disclosed herein, use is made of the piezo-electric transformer 9 formed as a rectangular plate measuring 7×2×1 mm which is prepared from polarized piezoceramics and having three electrodes (common, input and output ones) applied to the plate surface as a thin silver coating.
The rectifier 3 is built around diodes 10 and 11 and a capacitor 12 according to the voltage-doubling circuit.
The principle underlying the operation of the proposed radiocapsule resides in the variation of the resistance of the G-M counter 1 in response to the process of registering the ionizing particles.
To register ionizing radiation in the cavity of a human body under examination the radiocapsule is to be introduced directly into the cavity to be examined.
The initial resistance of the G-M counter 1 is not to exceed 10 12 ohms, whereas a discharge caused by ionizing particles results in the resistance dropping down to 10 6 -10 7 ohms.
Voltage necessary for the operation of the G-M counter 1 is fed thereto through the rectifier 3 from the output electrode of the piezo-electric transformer 9. A positive feedback voltage required for the inverter operation is fed from the same electrode through the capacitor 6 to the base of the transistor 5. Thus, the G-M counter 1 is thereby electrically connected to the inverter positive feedback circuit.
The resonance and degree of polarization of the transformer 9, as well as the value of the inductance 7 are so selected that the inverter operates under nominal (full-load) conditions only if the resistance of the G-M counter 1 loading the inverter reaches its maximum value, i.e., at zero discharge in the counter. As a result the inverter emits r.f. waves at a constant (maximum) amplitude and at an oscillator generation frequency which lies within the broadcast frequency bandwidth. The principal emitting element is the inductance 7. No signal appears at the output of the receiver which is incorporated into a radiotelemetric system (not illustrated in the drawing).
The dropped-down resistance of the G-M counter 1 resulting from a discharge occurring therein disturbs the phase and amplitude balance in the inverter feedback circuit which results in a momentary dropping of the amplitude of the inverter oscillations to nearly zero. This, in turn, causes forth an abrupt voltage fall across the G-M counter 1 and causes the extinction of the discharge therein, whereupon the inverter restores its normal operating conditions until a next ionizing particle is registered.
The short-time diminishing of the amplitude of the inverter oscillations and, consequently, of the amplitude of the r.f. waves emitted by the inverter, correspondingly causes a pulse to appear at the output of the receiver of the radiotelemetric system.
Thus, the amplitude modulation of the r.f. signals occurs due to the G-M counter 1 being interconnected with the inverter positive feedback circuit through the piezo-electric transformer 9.
As it is evident from the above description of the radiocapsule operation some of the elements thereof (transformer 9, inductance 7, G-M counter 1) perform a number of functions at a time. It is due to this fact that a high efficiency factor (mounting to 0.95) of the inverter of the present radiocapsule, high output power of the r.f. signals and jamming invulnerability of the radio transmission are attained. Provision of monofrequent amplitude-modulated r.f. signals ensures the required time resolution of the registration of ionizing radiation and makes simpler the construction of the radiotelemetric system as a whole.
The time for the continuous operation of the herein-proposed radiocapsule without requiring replacing of its power source is at least 48 hours. This makes the radiocapsule applicable in effecting prolonged measurements of ionizing radiation in the cavities of human body, particularly, in the gastro-intestinal tract. Furthermore, the present radiocapsule will find application for locating intestinal hemorrhages and tumors through the use of radioactive isotopes, as well as in investigating the cycles of accumulation of radioactivity in the uterine cavity.
There exist in the art nowadays radiocapsules for registration of ionizing radiation in the cavities of human body, comprising a detector which registers ionizing particles in the cavities of human body and modulates r.f. signals generated by an oscillator at the moment the ionizing particles are being registered.
In the aforementioned radiocapsules an r.f. oscillator is formed as a l.f. relaxation inverter of a d.c. voltage into an a.c. pulsing voltage, and with the inverter incorporating a multicircuit transformer. At the moment the ionizing particles are being registered, the detector causes the relaxation frequency of the inverter to vary, thereby providing frequency-pulse modulation of the r.f. signals being emitted.
Provision of a multicircuit transformer possessing a large number of turns in the prior-art radiocapsules adversely affects their reliability, renders them too complicated to make and inadequately small in size.
Furthermore, provision of the r.f. oscillator as a relaxation inverter featuring pulse frequency modulation, is responsible for the dissipated power of r.f. signals which, in turn, affects in a detrimental manner the jamming invulnerability of the radio emission, impedes the obtaining of the required time resolution of the ionizing emission registration and complicates the entire construction of a radiotelemetric system.
It is an object of the present invention to provide a radiocapsule for registering ionizing radiation in the cavities of human body that will ensure an increased reliability and a higher quality of the registration of ionizing radiation.
It is another object of the present invention to provide a radiocapsule for registering ionizing radiation in the cavities of human body which has a small size and an improved production technology therefore.
According to the above-stated objects in a radiocapsule for registration of ionizing radiation in the cavities of human body, comprising a detector which is to register ionizing particles in the cavities of human body and to modulate r.f. signals generated by an oscillator at the moment the ionizing particles are being registered,, the r.f. oscillator in accordance with the invention is made as an inverter of a d.c. voltage into an a.c. sine voltage and comprises a piezo-electric transformer electrically connected to the detector so as to ensure an amplitude modulation of the r.f. signals generated.
Such a construction of the herein-disclosed radiocapsule renders it more reliable, improved its production technology, reduces its size and simplifies the construction of a radiotelemetric system as a whole.
The nature of the present invention is explained in the following disclosure of an exemplary embodiment thereof in conjunction with the accompanying drawing, wherein a circuit schematic of the herein-proposed radiocapsule is represented.
Referring now to the drawing, the radiocapsule for registration of ionizing radiation in the cavities of human body, according to the invention comprises a detector which is adapted to register ionizing particles in the cavities of human body (not shown in the drawing), said detector including a Geigen Muller counter 1 which modulates the r.f. signals generated by an oscillator 2 at the moment when ionizing particles are being registered, as well as comprising a rectifier 3 and a d.c. low-voltage source 4 to supply power to the oscillator 2.
The r.f. oscillator 2 is made as an r.f. inverter for a d.c. voltage into an a.c. sine voltage, with the inverter comprising a transistor 5, a capacitor 6, an inductance 7, a resistor 8 and a piezo-electric transformer 9 which is electrically coupled through a rectifier 3 to the G-M counter 1 so as to ensure an amplitude modulation of the r.f. signals generated.
The piezo-electric transformer 9 can be of any arbitrary size and configuration. In the specific and preferred embodiment of the radiocapsule disclosed herein, use is made of the piezo-electric transformer 9 formed as a rectangular plate measuring 7×2×1 mm which is prepared from polarized piezoceramics and having three electrodes (common, input and output ones) applied to the plate surface as a thin silver coating.
The rectifier 3 is built around diodes 10 and 11 and a capacitor 12 according to the voltage-doubling circuit.
The principle underlying the operation of the proposed radiocapsule resides in the variation of the resistance of the G-M counter 1 in response to the process of registering the ionizing particles.
To register ionizing radiation in the cavity of a human body under examination the radiocapsule is to be introduced directly into the cavity to be examined.
The initial resistance of the G-M counter 1 is not to exceed 10 12 ohms, whereas a discharge caused by ionizing particles results in the resistance dropping down to 10 6 -10 7 ohms.
Voltage necessary for the operation of the G-M counter 1 is fed thereto through the rectifier 3 from the output electrode of the piezo-electric transformer 9. A positive feedback voltage required for the inverter operation is fed from the same electrode through the capacitor 6 to the base of the transistor 5. Thus, the G-M counter 1 is thereby electrically connected to the inverter positive feedback circuit.
The resonance and degree of polarization of the transformer 9, as well as the value of the inductance 7 are so selected that the inverter operates under nominal (full-load) conditions only if the resistance of the G-M counter 1 loading the inverter reaches its maximum value, i.e., at zero discharge in the counter. As a result the inverter emits r.f. waves at a constant (maximum) amplitude and at an oscillator generation frequency which lies within the broadcast frequency bandwidth. The principal emitting element is the inductance 7. No signal appears at the output of the receiver which is incorporated into a radiotelemetric system (not illustrated in the drawing).
The dropped-down resistance of the G-M counter 1 resulting from a discharge occurring therein disturbs the phase and amplitude balance in the inverter feedback circuit which results in a momentary dropping of the amplitude of the inverter oscillations to nearly zero. This, in turn, causes forth an abrupt voltage fall across the G-M counter 1 and causes the extinction of the discharge therein, whereupon the inverter restores its normal operating conditions until a next ionizing particle is registered.
The short-time diminishing of the amplitude of the inverter oscillations and, consequently, of the amplitude of the r.f. waves emitted by the inverter, correspondingly causes a pulse to appear at the output of the receiver of the radiotelemetric system.
Thus, the amplitude modulation of the r.f. signals occurs due to the G-M counter 1 being interconnected with the inverter positive feedback circuit through the piezo-electric transformer 9.
As it is evident from the above description of the radiocapsule operation some of the elements thereof (transformer 9, inductance 7, G-M counter 1) perform a number of functions at a time. It is due to this fact that a high efficiency factor (mounting to 0.95) of the inverter of the present radiocapsule, high output power of the r.f. signals and jamming invulnerability of the radio transmission are attained. Provision of monofrequent amplitude-modulated r.f. signals ensures the required time resolution of the registration of ionizing radiation and makes simpler the construction of the radiotelemetric system as a whole.
The time for the continuous operation of the herein-proposed radiocapsule without requiring replacing of its power source is at least 48 hours. This makes the radiocapsule applicable in effecting prolonged measurements of ionizing radiation in the cavities of human body, particularly, in the gastro-intestinal tract. Furthermore, the present radiocapsule will find application for locating intestinal hemorrhages and tumors through the use of radioactive isotopes, as well as in investigating the cycles of accumulation of radioactivity in the uterine cavity.