CA1197631A
Expired / Lapsed
CA
⏱️ 0.0 years remaining
Radiotherapy apparatus
Assignee: Princess Margaret Cancer Centre
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Filing: 1982-07-21
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Granted: 1985-12-03
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Expires: 2002-07-21
Abstract
Abstract ABSTRACT OF THE DISCLOSURE In radiotherapy use is made of apparatus of the type in which a chain of balls comprising radioactive balls and inert spacer balls is moved pneumatically to and from an applicator tube within the patient, the spacer balls are made of a material such as nylon which is softer and less dense than the radioactive balls, and is radiographically transparent. This reduces wear and tear on the radio- active balls and facilitates control of dosage and moni- toring of the treatment. The balls are sorted after use by means of a radiation detector. The ball chain has a larger diameter end ball of ferromagnetic material, which blocks air flow through the applicator when correctly located therein, and whose position can be verified by an induction air coil. By assembling and storing the chain in a storage tube having two air inlets, respectively above and below the end ball, and choking the lower inlet, air may be selectively applied to the inlets to expel the chain from the storage tube either with its end ball for transport to the applicator tube, or without its end ball for sorting. Use of the lower inlet alone enables pres- sure retaining the chain in the applicator to be maintained only in the absence of send out air flow through the applicator tube, thus enabling malfunctions to be detec- ted.
Inventors
- 👤 Philip M. Leung
- 👤 Henry P.J. Webb
Bibliographic Details
Application Number
—
Jurisdiction
CA
Data Source
google_patents
Last Synchronized
2026-10-23 18:56
CPC Classifications
A; A61; A61N; A61N5/00; A61N5/10; A61N5/1001; A61N5/1007; A61N2005/1008
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
54 words
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS: 1. A ball chain for use in radiotherapy treatment com- prising a plurality of radioactive balls separated by non-radioactive spacer balls of radiographically trans- parent material of lower density and surface hardness than the radioactive balls.
Claim 2
Dependent Claim
14 words
A ball chain according to Claim 1, wherein the spacer balls are of nylon.
Claim 3
Dependent Claim
44 words
A ball chain according to Claim 1, wherein the radio- active and spacer balls are of the same diameter, and the chain includes an end ball of larger diameter and having a further physical characteristic distinguishing it from the remaining balls in the chain.
Claim 4
Dependent Claim
15 words
A ball chain according to Claim 3, wherein the end ball is of ferromagnetic material.
Claim 5
Dependent Claim
150 words
Radiotherapy treatment apparatus comprising a storage, sorting and assembly system for radioactive balls and non- radioactive spacer balls of radiographically transparent material of lower density and surface hardness than the radioactive balls, the system including a sorter compri- sing a radiation detector, means to transport the balls past the radiation detector, and means receiving the radiation detector output and operative to divert the balls into different ball storage compartments depending upon whether or not the radioactive detector output ex- ceeds a predetermined threshold, an assembler comprising means for selectively and successively releasing balls from said ball storage compartments into a ball chain store to assemble a ball chain, means for pneumatically conveying a ball chain between the ball chain store and a remote applicator tube for location within the body of a patient, and means for pneumatically conveying a ball chain from the ball chain store to the sorter. 11
Claim 6
Dependent Claim
12 words
Apparatus according to Claim 5, wherein the spacer balls are of nylon.
Claim 7
Dependent Claim
42 words
Apparatus according to Claim 5, wherein the radio- active and spacer balls are of the same diameter, and the chain includes an end ball of larger diameter and having a further physical characteristic distinguishing it from the remaining balls in the chain.
Claim 8
Dependent Claim
13 words
Apparatus according to Claim 7, wherein the end ball is of ferromagnetic material.
Claim 9
Dependent Claim
118 words
Apparatus according to Claim 7, wherein the ball chain store comprises a vertical tube of length and di- ameter sufficient to accommodate a ball chain, a seating at the bottom of the tube to receive the larger diameter end ball of a chain, a first air inlet into the tube im- mediately above said seating, and a second choked air inlet into the tube immediately below said seating, whereby air may be admitted only to said first air inlet to expel the readioactive and spacer balls from the tube whilst leaving the end ball, to said both inlets to expel the entire chain, and to the second inlet only to permit a limited air flow into the tube.
Claim 10
Dependent Claim
134 words
Apparatus according to Claim 9, wherein the applica- tor tube comprises a first tube of a length and diameter just sufficient to accommodate the radioactive and spacer balls but not the end ball, a second tube connected by a shoulder to one end of the first tube and to a tube comprised of said means for pneumatically conveying the chain between the ball chain store and the applicator tube, the second tube being of large enough diameter to accommodate the end ball, whereby the latter can seat on said shoulder, and a third blind ended tube surroun- ding the first and second tubes, the other end of the first tube having means to arrest said balls whilst per- mitting air to pass to or from the third tube to complete 12. a pneumatic circuit.
Claim 11
Dependent Claim
40 words
Apparatus according to Claim 10, wherein the end ball is of ferromagnetic material, and the applicator tube in- cludes an inductance coil wound around the second tube adjacent said shoulder to detect the presence or absence of the end ball.
Claim 12
Dependent Claim
32 words
Apparatus according to Claim 5 or 9, wherein the means receiving radiation detector output has plural thresholds, and radioactive balls are divertable into different ball storage compartments dependent upon the threshold exceeded.
Claim 13
Dependent Claim
44 words
Apparatus according to Claim 5, comprising plural ball chain stores and an applicator tube associated with each ball chain store, and channel selector means opera- tive to direct balls released from the storage compart- ments into a selected one of the ball chain stores.
Claim 14
Dependent Claim
65 words
Apparatus according to Claim 5, 9 or 13, comprising a function selector operative to connect the or each ball chain store selectively to receive balls from said stores, to a tube comprising the means for conveying a ball chain to the sorter, or to a tube comprised by the means for conveying a ball chain between the ball chain store and its associated applicator tube.
Claim 15
Dependent Claim
37 words
Apparatus according to Claim 9, comprising photo- electric means located at the top of the tube so as to detect the passage of each ball entering the store, and to detect when the store is full. 13
References Cited (Backward Citations)
No citation records indexed.
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