Abstract:
A radiation detection apparatus includes a scintillation counter, a download control device for outputting a scintillation count to a utilization device, and a hand-held probe including a scintillation detector. The apparatus also includes a connector for connecting the probe to the counter, and a switch assembly removably mounted to the probe. The switch assembly has a first trigger for causing the counter to accumulate a first scintillation count over a first period, the counter to accumulate a second scintillation count over a second period, and the detection apparatus to display the second scintillation count. The switch assembly has a second trigger for causing, upon activation, the download control device to manifest an accumulated scintillation count from the counter. A lack of activation of the second trigger during the display of the second scintillation count causes the counter to resume accumulating scintillation counts over the first period.

Description:
This application is a Divisional application Ser. No. 09/177,636 filed on Oct. 23, 1998 now U.S. Pat. No. 6,242,741, filed Jun. 5, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a radiation detection apparatus. More particularly, the present invention relates to an apparatus for detecting, quantizing and mapping radiation emitted from a scintillation fluid having gamma-emitting isotopes. The apparatus is battery operated and has a hand-held probe for detecting radiation, and for transmitting electrical signals that represent the detected radiation to a remote unit to process the signals into information. The hand-held probe is a scintillation detector that has a switch assembly removably mounted on the probe for initiating remotely electrical signals to a control unit. 
     The switch assembly has preferably two finger-operated triggers. One trigger initiates the count, and the other trigger directs the remote unit to download, and preferably record, the counted scintillations or averaged scintillation values for further use. 
     2. Description of the Prior Art 
     Procedures for detecting, quantizing and localizing or mapping carcinomas in living beings are known. A radiation-emitting substance is passed through a patient&#39;s body. Either a radiation detector device is secured to the patient&#39;s body, or a hand-held probe is held adjacent a series of sites surrounding a suspected tumor. One procedure involves injecting a scintillation fluid containing, for example, technetium 99, in quadrants of the capillary system located about a site to determine whether cancer has spread to the lymphatic system. Since fluid drains from the injected area through the lymphatic system, the scintillation detector allows identification and location of the sentinel node, the first lymph node draining the most scintillation fluid and emitting the highest number of scintillations in the lymphatic drainage path from the tumor. 
     Heretofore, each radiation detecting, quantizing and mapping apparatus has been connected by hardwire to an electrical receptacle or has a battery that discharges during use. One conventional apparatus has a foot pedal connected to a remote unit to initiate counts. The foot pedal does not activate a downloading of counts, let alone during a preset time period. A second conventional apparatus has a built-in rechargeable battery. This is disadvantageous since an extended time, usually four to six hours, is required to recharge the battery. Since recharging cannot occur during operation of the apparatus, should the battery require recharging during a procedure, the procedure must be stopped. 
     In addition, the apparatus has a hand-held probe and a remotely located control unit. The probe was merely used for detecting emitted radiation from the patient&#39;s body and transmitting electric signals representing the detected radiation to the control unit for processing. The control unit has the controls for controlling various functions including taking counts, setting the time period for taking timed counts, and initiating the taking of counts. These controls had to be activated solely at the control unit. This is disadvantageous because to conduct the counting procedure, the operator must hold and use the hand-held radiation detection probe with one hand. With the other hand, the operator needed to reach the control unit and manipulate the controls. It is difficult to conduct both the detection and control manipulation simultaneously. Also, to do so results in difficulties in taking counts and, perhaps, inaccuracies in the counts. For example, while taking a scintillation count, the probe must be precisely positioned over a selected site for a set period of time. It is difficult to maintain that precise position while reaching to depress a count start button on the control unit. Movement of the probe during counting can create an inaccurate count. Since counting is repeated at different probe angle positions over the same site and over different body sites, the difficulties and inaccuracies can be compounded. Therefore, it is desired to have an improved radiation detection apparatus that obviates or reduces such difficulties, inaccuracies and inefficiencies. 
     It is known to employ switches removably mounted on a handpiece. U.S. Pat. No. 5,304,763 discloses two or more finger-operated switches removably mounted to a hand-held electrosurgical device. The switches control the application, e.g., initiation and termination, of electrical energy provided to the device. For example, one switch controls the application of energy to energize an electrode of the device for cutting body tissue. The other switch energizes a suction portion of the device to remove cut tissue from the body. 
     Heretofore, hand-held radiation detection probes and their cables have had to be sterilized to be re-usable because they become contaminated during use. Sterilizing such hand-held detection devices prior to each use is expensive, time consuming and may require maintaining a larger than necessary inventory of the probes and cables. It is desired to have an apparatus that obviates the need for sterilizing hand-held devices or probes prior to their re-use. It would also be desired to have an apparatus that allows for the use of hand-operated switches mounted on the hand-held device or probe during use, but permits removal from it during sterilization of the device or probe. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an improved radiation detection apparatus that includes a hand-held radiation detection probe with at least one switch removably mounted thereon. 
     It is another object of the present invention to provide such a radiation detection apparatus in which the one switch has a first trigger or button that remotely enables a counter in a control unit to accumulate electrical signals representing radiation scintillation detected over a set time period, and a second button that remotely directs the control unit to ouput data regarding the counted scintillations. 
     It is still another object of the present invention to provide such a radiation detection apparatus that allows the operator to operate a hand-held probe, while simultaneously using the switches mounted on the probe to control a remote control unit. 
     It is yet another object of the present invention to provide such a radiation detection apparatus in which the control unit is battery operated to provide total mobility of the control unit. 
     It is a further object of the present invention to provide such a radiation detection apparatus that has a removable, rechargeable battery as its power source. 
     It is still a further object of the present invention to provide such an improved radiation detection apparatus that enables a hand-held radiation detection probe to be reused without prior sterilization. 
     It is yet a further object of the present invention to provide such a hand-held radiation detection probe with a cover to protect the probe from contamination during use, and to isolate electrically the switch from the hand-held probe. 
     It is still yet a further object of the present invention to provide such an improved radiation detection apparatus that is removably mounted on a movable stand. 
     These and other objects of the present invention are achieved by a radiation detection apparatus comprising: means for counting a scintillation count value; means for outputting a scintillation count value to a utilization device; a hand-held probe including a scintillation detector; means for connecting the probe to the count means; first means removably positioned on the probe for, in a first state, causing the count means to accumulate a scintillation count over a first period, and in a second state, causing the count means to accumulate a scintillation count over a second period, the second period being longer than the first period; and second means removably positioned on the probe for causing, upon activation, the output means to manifest an accumulated scintillation count from the count means. 
     The radiation detection apparatus can include means for displaying a count value of the count means. The display means responds to activation to the second state of the first means, by displaying a count value accumulated over the second period for a preset time period. 
     Preferably, activation of the second means is operative, only during the preset time period, to cause the output means to manifest a scintillation count accumulated during the second period from the counter means. Activation of the second means, at times other than during the preset time period, causes activation of any selected other function of the control unit. 
     The radiation detection apparatus can include a movable stand having a holder for releasably mounting the probe on the stand. 
     The present invention also includes a hand-held radiation detection probe having a flexible removable protective covering thereover to protect the probe from contamination during storage or use, and permit the probe to be re-used without prior sterilization. Preferably, the covering is a sheath. 
     The present invention may further include a hand-held radiation detection probe having a switch assembly removably mounted thereon. The switch assembly has at least one switch, an insulating member for electrically insulating said switch from said probe which is a saddle formed by a spaced, opposed pair of cooperative depending gripping members adapted to releasably grip said probe therebetween. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic representation of the radiation detection apparatus of the present invention; 
     FIG. 2 is a top plan view, with portions broken away, of a preferred embodiment of the probe shown in FIG. 1; 
     FIG. 3 is a top plan view, with portions broken away, of the probe shown in FIG. 2 without a switch mounted thereon and covered by a sheath; 
     FIG. 4 is a top plan view, with portions broken away, of the probe shown in FIG. 2 covered by a sheath and having a switch assembly mounted thereon; 
     FIG. 5 is a top plan view, with portions broken away, of the probe shown in FIG. 2 covered by a drape and with a switch assembly shown optionally mounted thereon; 
     FIG. 6 is a perspective view of the removable switch assembly that is mounted on the probe shown in FIG. 2; 
     FIG. 7 is an exploded perspective view of the switch assembly shown in FIG. 6; 
     FIG. 8 is a front view of the housing of the control unit of the present invention; 
     FIG. 9 is a front perspective view of a movable stand for mounting the control unit of the radiation detection apparatus of FIG. 1; and 
     FIG. 10 is a rear perspective view, with portions broken away, of the control unit and stand shown in FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and, in particular, FIG. 1, there is a schematic of a preferred embodiment of the radiation detection apparatus of the present invention, generally represented by reference number  10 . Apparatus  10  includes a hand-held radiation detection device or probe  50 , and a control unit  100  connected to probe  50  by a suitable connection, such as a flexible cable  12 . Probe  50  includes a radiation detector  52 , a handle  54 , and a shaft  56  that connects detector  52  to handle  54 . Detector  52  includes a crystal, such as a cadmium telluride crystal, for detecting radiation, such as gamma protons, emitted from a radiation source in a patient&#39;s body. The radiation source is a scintillation fluid preferably containing technetium 99. 
     Probe  50  converts the detected scintillation radiation into electrical pulses that are amplified and transmitted through cable  12  to control unit  100 . Removably mounted to probe  50  is a switch assembly  70 . Assembly  70  preferably has two switches  72 ,  74 . Switches  72 ,  74  are preferably push button switches. 
     Activation of switch  72  enables a count accumulator module  158 , described below, to accumulate a scintillation count over a preset time period, such as ten seconds. Otherwise, scintillation counts are accumulated over succeeding one second periods. The scintillation pulses detected by probe  50  pass from the probe through cable  12  to a pulse shaping circuit  150  where the scintillation pulses are shaped. The shaped pulses are fed to a discriminator  152  which passes pulses that fall within an energy window that has been preset for technetium 99 by an energy window set  154 . The pulses passed by discriminator  152  are fed to an audio unit  156  where they are broadcast to aid the probe operator in positioning probe  50 . 
     Pulses from discriminator  152  are also fed to a counter, for example a count accumulator module  158 . Module  158  counts the scintillation pulses and averages them, in the normal operational mode, over succeeding one second periods, or over a preset period, such as a ten second period, if selected by the probe operator&#39;s activation of switch  72  instead of pressing button  108  on control unit  100 . The accumulated and averaged count value is passed from count accumulator module  158  to a display unit  160  that displays the averaged count value for each one second period, or for the preset 10 second period. 
     Upon activation of switch  74  on probe  50 , the accumulated and averaged count value is also passed from module  158  through a download control  162  and output to a terminal, here shown as output terminal  164 . Output terminal  164  can be connected to a utilization device, such as a recorder  166 . Output terminal  164  may also be connected, directly or remotely, to a computer  168 . Computer  168  can be, for example, a personal computer, laptop, or other computing device, for storage and manipulation of the output data. 
     The electronic signals sent by control unit  100  to computer  168  represents the ten second count frozen and shown on display  160 . Signals received by computer  168  will be received by its software which will record the signals, for example, to keep patient records of how control unit  100  was used (settings, duration, etc.). The software can be tailored to individual preferences or to established clinical protocols. However, control unit  100  and probe  50  must be kept electrically isolated from computer  168 , and the computer must not be able to control, program or otherwise affect the performance of the control unit or the probe. Thus, a unidirectional (control unit  100  to computer  168 ) isolated interface, e.g. optical coupler (represented by the heavy dashed line II) is employed should the computer be connected to output terminal  164 . 
     After a patient has been injected with a radiation emitting substance, for example, a scintillation liquid containing technetium 99, hand-held probe  50  is held stationary in position over a radiation detection site on the patient&#39;s body. A count is taken of the scintillation detected at that site for a given time period. This process is repeated at one or more different sites, or for different angular positions of the probe on the same site, and a comparison is made of the counts obtained at each site. With switch  72  in a deactivated position, scintillations are detected or sampled over a series of first count sampling periods. Each sample period is, for example, preferably of one second duration. The signals or pulses transmitted from probe  50  during each one second period cause count accumulator module  158  to accumulate a scintillation count that is an average of the scintillation pulses over the one second period. 
     Control unit  100  is set such that activation of switch  72  initiates a ten second count sampling period, followed by a three second freeze period of the average count taken for the ten second period. During the ten second sampling period, module  158  accumulates and averages the scintillation counts taken over the ten second period. The average count is displayed on display  160  for the three second freeze period. During the sampling period, a sampling light (not shown) on control unit  100  will flash. At the end of the sampling period, the sampling light goes off and a single audible beep is emitted. If, during the three second freeze period, switch  74  is activated by the operator, the frozen count is downloaded from module  158  to output terminal  164  which sends the frozen count to a utilization device. 
     When switch  74  is activated during the three second period, two audible beeps are emitted. If switch  74  is not activated during the freeze period, no downloading of the frozen count occurs. Switch  74  can be activated during or at the end of any one second count sampling period or, as stated above, during the three second freeze period. Thus, activation of switch  74  downloads the ten second count value to output terminal  164 , and an audible signal indicates that the download has occurred. If switch  74  is not activated during the three second freeze period, module  158  returns to its normal mode of accumulating and averaging sampled counts per second and displaying the counts per second on display  160 . 
     Control unit  100  is powered by a removable, rechargeable battery. The preferred battery is a lead-acid rechargeable battery capable of four hours of continuous operation. When a predetermined set period of time of power battery life remains, such as, for example, fifteen minutes, a warning indicator, such as a light, will flash or indicate the commencement of that set period. Accordingly, the user can simply insert a second battery in the control unit  100  to operate the control unit, and the first battery can simply be recharged when desired. 
     As shown in FIG. 2, switch assembly  70  is removably mounted on handle  54  of probe  50 . Switch assembly  70  preferably has two finger-operated push button switches  72 ,  74 . 
     Referring to FIG. 3, probe  50  may have a removable protective cover  60  placed thereover. The protective cover  60  preferably is a sheath that substantially fully encompasses probe  50  to protect it from being soiled or contaminated during storage and use. Sheath  60  permits probe  50  to be re-used without prior sterilization. Sheath  60  has a closed end  62  that covers detector  52 , and an opposite open end  64  that can be at any desired location beyond handle  54 . Preferably, sheath  60  is long enough to the entire length of cable  12 , as shown in FIG.  2 . 
     Sheath  60  can have any suitable size, shape and configuration. Thus, it can fit loosely, tightly or form-fitted or even shrunk onto probe  50 . As shown in FIG. 4, sheath  60  preferably fits sufficiently tightly onto probe  50 , especially about detector  52 , to minimize interference with its function. Sheath  60  preferably also fits tightly about the portion of handle  54  onto which switch assembly  70  is to be mounted, to enable the switch assembly to remain tightly and securely mounted onto the handle. Sheath  60  can be made of any suitable material or materials, and can be single or multiple layered. Preferably, sheath  60  is made from a flexible film or sheet. The preferred material for sheath  60  is a single layer of polyurethane. 
     Although sheath  60  is the preferred cover, any suitable cover can be employed that permits switch assembly  70  to be effectively mounted onto probe  50 . The sheath  60  is removable and preferably disposable and easily replaceable. Thus, as shown in FIG. 5, a drape  66  of flexible film can be placed over and secured to probe  50 . As shown in FIG. 5, a continuous portion of drape  66  can be placed over detector  52 , tied around shaft  56  by a tie  68 , and gathered and secured about handle  54  or about cable  12  (not shown) by any suitable member, such as by a clip  69 . Switch assembly  70  (dashed line) can be mounted on probe  50  while the switch assembly is covered by drape  66 . 
     Referring to FIG. 6, switch assembly  70  preferably has a saddle  76  formed by a curved undersurface  78  and a pair of spaced opposed cooperative depending gripping members  80  that are adapted to releasably grip probe  50  (not shown) between them. Gripping members  80  are arcuately shaped and sized to fit tightly about handle  54  of probe  50 . Gripping members  80  are rigid enough to hold probe  50  between them, but resilient enough to allow the switch assembly  70  to be removed from the probe. 
     As shown in FIG. 7, the preferred switch assembly  70  also has a cover  82 , button switches  72 ,  74 , a carrier in the form of a mounting member  84  having saddle  76 , a recessed panel  86 , and an insulating member  88  that fits into recessed panel  86  and insulates the switches and any electrical wiring and connections (not shown) from probe  50  (not shown). In a preferred embodiment, there are two switches  72 ,  74 . However, it is possible that these switches may be combined into a single switch or that a third or more switches may be added to control remotely other functions of control unit  100 . 
     Referring to FIG. 8, housing  212  of control unit  100  has a power button  102 , a plurality of holes  104 , preferably three, for operatively receiving a three prong plug of cable  12 , a receiver  106  for operatively receiving a plug connected to probe  50 , and a digital display  130 . Housing  212  also has a button  108 , which is preferably a push button, that initiates the ten second count time period, a light  110  that lights during the ten second period, a calibration indicator  112 , and a battery charge indicator light  114 . Housing  212  also has a volume control knob  116 , a plurality of volume indicators  118 , preferably light indicators, a knob to deactivate an internal threshold and window pre-set for technetium 99 to permit setting a wider window, a light indicator  122  for the internal threshold, and an audio range knob  124  to change the audio range from among the three values indicated by lights  126 ,  128  and  130 . Referring to FIGS. 6 and 8, when switch  72  of switch assembly  70  is activated, button  108  is activated and, thus, light  110  is activated. When switch  74  is activated to download or record a count, an audible signal is provided. 
     FIGS. 9 and 10 show a movable stand  200  suitable for use with radiation detection apparatus  10  of the present invention. Stand  200  has an upper vertical shaft  202  telescopically seated with a lower vertical shaft  204 . Shaft  204  is mounted at its bottom end onto the hub of a plurality of radially outwardly extending legs  206  supported on rotatable wheels  208 . Shaft  202  is held at a desired height by an adjustable restrainer  205  on the top end of shaft  204 . The upper end of shaft  202  has an adjustable fastener  210  mounted thereon. Fastener  210  has a horizontal shaft (not shown) onto which the lower end  211  of a bracket  214  is rotatably mounted. A housing  212  of control unit  100  is secured to bracket  214 . Bracket  214  and housing  212  can be tilted up and down to a desired angle about the shaft of fastener  210  and held at the desired angle by tightening threaded bolt  215 . 
     Lower shaft  204  preferably has a pair of holders  220  mounted thereon. Each holder  220  has a pair of spaced, vertically disposed opposed holding members  222  adapted, e.g. shaped, to receive and releasably hold probe  50 . Each holder  220  is positioned within a protective box  224  having a cover  226 . Lower shaft  204  preferably has a support  228  for supporting cable  12  for probe  50 . Onto the rear of lower shaft  204 , there is preferably fixedly mounted the lower end of an elongated bracket  230 . Bracket  230  has a platform  232  welded or otherwise fixed thereto. Platform  232  preferably is for supporting an auxiliary component such as a computer (not shown). The side of housing  212  has an angularly disposed rectangular cavity at  234  for holding and accessing the replaceable rechargeable battery (not shown) to supply power to control unit  100 . 
     The present invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the present invention as defined in the appended claims.