[0001] The present invention relates to any handswitch operated equipment generally, including
medical diagnostic equipment and, more particularly, to a handswitch associated with
mobile radiation equipment.
[0002] Many products require an associated handswitch for operation, including, for example,
a variety of medical diagnostic devices. Handswitches are used to operate most X-ray
devices, such as mobile battery-powered X-ray devices. Handswitches can also be used
to operate nuclear medicine and radiation therapy devices.
[0003] When making an X-ray exposure with mobile radiation equipment, it is necessary to
have an audible indication that an exposure has occurred, such as following activation
of an EXPOSE switch on the equipment. This is often accomplished with a tone generator
inside of the X-ray console. A difficulty often arises, however, because the operator
makes the exposure from a remote location, using a hand held switch. Depending on
the distance to the console and the location of the operator, the tone may be difficult
to distinguish, particularly in a noisy environment.
[0004] Since it is good practice for the technician to stand as far as possible from the
X-ray source when making an exposure, it is not possible to resolve the audibility
problem by making the tone louder, because then the tone is objectionably loud to
patients, as well as to the operator when it is necessary to attend the patient while
making an exposure.
[0005] This problem is made worse by the fact that the exposure switch is often operated
in series with a contact, or PREP, switch that commands the x-ray system to prepare
for the EXPOSE command. The function of the PREP switch is to bring the X-ray tube
rotor up to speed, so that an X-ray can be generated as soon as the EXPOSE switch
is pressed, without any delay. It is often necessary to press and hold the PREP switch
while waiting for the patient to enter the optimum position, and then pressing the
EXPOSE switch. Holding of the PREP switch can be from a couple of seconds up to about
a minute. Other than the sound of the rotor and a display, which can be difficult
to distinguish in a noisy environment or to see when far from the X-ray machine, there
is no indication to the operator that PREP has been selected, or if it has been inadvertently
released.
[0006] It would be desirable then to have a handswitch constructed with an exposure indicator
associated directly with the handswitch, so that wherever the operator may be located
when an exposure is made, the occurrence of the exposure is immediately realized by
the operator. It would further be desirable to have such a handswitch which is capable
of providing PREP function activation feedback to the operator of the handswitch.
[0007] The present invention proposes a handswitch wherein an exposure indication means
is directly associated with the handswitch to convey immediate occurrence of an exposure
to the operator, and a PREP function activation means immediately conveys to the operator
whether the PREP function is activated. The handswitch according to the present invention
is adaptable for use with all products requiring a remote handswitch.
[0008] In accordance with one aspect of the present invention, a handswitch held by an operator
of any equipment requiring the use of a handswitch to operate the equipment, comprises:
an exterior housing for fitting into the hand of an operator; an interior portion
housed within the exterior housing; an exposure switch situated on the exterior housing
for operating the X-ray exposure; and an exposure indication means in the interior
portion for indicating to the operator when an X-ray exposure has occurred.
[0009] A preferred embodiment of the present invention may further comprise a prepare switch
situated on the exterior housing which, when selected, prepares the system for an
X-ray exposure; and a prepare switch activation indication means in the interior portion
for indicating to the operator when the prepare switch is being activated.
[0010] Accordingly, it is an object of the present invention to provide a handswitch capable
of providing an exposure occurrence indication to the operator of the handswitch.
It is a further object of the present invention to provide such a handswitch wherein
the exposure occurrence indication is directly associated with the handswitch. It
is yet another object of the present invention to provide a PREP switch activation
indication to the operator of the handswitch.
[0011] An embodiment of the invention will now be described, by way of example, with reference
to the accompanying drawings, in which:-
Figs. 1A and 1B illustrate a perspective view of a typical handswitch and an exploded
view of the same handswitch, respectively, configured in accordance with the present
invention; and
Fig. 2 is a schematic block diagram illustrating activation of the exposure indication
means and activation of the PREP function feedback when the corresponding switch of
the handswitch of Figs. 1A and 1B is depressed.
[0012] Handswitchable equipment is very common in many fields, for example, the medical
diagnostic field, including X-ray devices, nuclear medicine devices, and radiation
therapy devices. To indicate activation of various switches on the handswitch, the
X-ray console, often remote from the handswitch, can provide an audible feedback indicative
of the switch usage. However, since the operator of the handswitch is often at some
distance away from the X-ray source, the audible feedback from the X-ray source is
difficult to hear.
[0013] Referring now to Figs. 1A and 1B, there is illustrated a typical handswitch 10, for
use with any handswitchable equipment, comprising integral feedback means to indicate
to the operator that certain switches have been activated. The handswitch 10 comprises
an exterior housing 12 and an interior portion 14. The exterior housing 12 typically
includes interactive means, such as switches and/or dials, controlled by an operator
for operating associated handswitchable equipment (not shown). Specifically, as illustrated
in Fig. 1A, the exterior housing 12 can include a two position switch 30, which is
depressed to a first position 16 to prepare the system while waiting for the patient
to enter the optimum position, and depressed to a second position 18 when the patient
is situated and an X-ray exposure is desired. A typical handswitch 10 may also include
cord receiving means 20 for receiving a cord 22 attached at its other end to the diagnostic
equipment (not shown).
[0014] Continuing with Fig. 1B, the interior portion 14 comprises an exposure occurrence
indicator, such as tone generator 24, to provide an audible feedback to the operator
when an exposure is made. The tone is an indication that x-rays are "on". Hence, it
is possible to have the EXPOSE position 18 of switch 30 pressed with no tone being
generated. Similarly, it is possible to have the PREP position 16 of switch 30 active,
without a vibration feedback, where the vibration feedback is an indication that the
system is preparing for x-ray exposure.
[0015] The interior portion 14 may comprise a PREP switch activation indication means for
indicating to the operator that the first position 16 of switch 30 is being activated.
The PREP switch activation indication means may be any suitable feedback means, such
as a vibrating mechanism 26 to provide positive tactile feedback that the PREP function
is being activated.
[0016] Fig. 2 is a simple schematic block diagram illustrating activation of the prepare
switch activation indication means 26 and activation of the exposure indication means
24 when the two position switch 30 on the handswitch 10 of Figs. 1A and 1B is depressed.
The exposure position 18 of switch 30 is operated in series with the prepare position
16 of switch 30, where "prepare" control circuitry 32 commands the x-ray system to
prepare for the EXPOSE command, controlled by "expose" circuitry 34. The function
of the PREP position 16 of switch 30 is to bring rotor 36 of X-ray tube 42 up to speed,
via rotor control logic 38. This prepares the system for high voltage at 40 so that
an X-ray can be generated as soon as the EXPOSE position 18 of switch 30 is pressed,
without any delay. When the system is ready for x-ray exposure, the prep feedback
26 indicates this to the operator. The expose switch then causes x-ray exposure via
filament control logic 44. Tone generator 24 indicates when the x-rays are "on".
[0017] It is often necessary to press and hold the PREP position 16 while waiting for the
patient to enter the optimum position, and then pressing the EXPOSE position 18. Holding
of the PREP switch can be from a couple of seconds up to about a minute. The prep
feedback 26 allows the system operator to know when the system is ready for x-ray
exposure, which can otherwise be difficult to distinguish in a noisy environment or
to see when far from the X-ray machine. Furthermore, the expose feedback 24 indicates
to the system operator that the switch has been depressed to the expose position 18
and that the x-rays are "on".
[0018] It will be obvious to those skilled in the art that the present invention provides
a number of advantages over the prior art. The advantage of providing an exposure
indication means, such as tone generator 24, is that the source of the "X-ray On"
alert travels with the operator. Therefore, even in extremely noisy environments,
the operator would have the ability to hold the handswitch, and thus the tone generator,
close to the ear, practically guaranteeing that the tone will be heard. The advantage
of the PREP activation indication means, particularly with the proposed vibration
mechanism 26, is that the operator receives continuous tactile feedback when the X-ray
system is in a PREP state and ready to take an exposure. This eliminates the undesirable
condition where the operator is unaware of a lost PREP state, because of either an
operator error or system malfunction, and the operator does not know of the lost state
until an exposure is attempted. Under critical conditions, such as in a surgery, this
is particularly undesirable.
1. A handswitch held by an operator of an x-ray system using handswitchable equipment
to operate the x-ray system, the handswitch comprising:
an exterior housing for fitting into the hand of an operator;
an interior portion housed within the exterior housing;
an exposure switch situated on the exterior housing for operating the X-ray exposure;
and
an exposure indication means in the interior portion for indicating to the operator
when an X-ray exposure is in process.
2. A handswitch as claimed in claim 1 further comprising:
a prepare switch situated on the exterior housing to prepare the system for an X-ray
exposure when the prepare switch is activated;
a prepare switch activation indication means in the interior portion for indicating
to the operator when the system is prepared for an immediate exposure.
3. A handswitch as claimed in claim 1 wherein the exposure indication means comprises
an audible feedback.
4. A handswitch as claimed in claim 2 wherein the prepare switch activation indication
means comprises a positive tactile feedback.
5. A handswitch as claimed in claim 2 wherein the exposure switch and the prepare switch
comprise two positions of a single multi-position switch.