Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02451257 2003-11-27
200217538
Description
Display and control element for an X-ray unit
The invention relates to a display and a control
element for an X-ray unit.
In clinical work environments, rational working methods
and a high degree of automation are demanded in order
to allow efficient and economic working.
Rationalization in radiological departments have
reduced the break intervals between X-ray shots to such
a great extent that the time required for an X-ray tube
which is in operation to cool down is often no longer
achieved in the break intervals. Furthermore, peak
traffic operation occurring in emergency diagnostics
can also occasionally result in the break intervals
being shortened to a critical degree in no time.
Particularly susceptible to destruction as a result of
overheating is the anode plate in a X-ray tube. The
temperature of the anode plate can be monitored by
measurement, or the thermal loading thereof can be
simulated in a tube load computer using a computation
model. Limit values for the thermal loading are
prescribed by the manufacturer according to the tube
type. When a thermal loading limit is reached, whether
it be as a result of said limit being exceeded or as a
result of the immediate imminence of said limit being
exceeded, which could result in the X-ray tube or the
anode plate being damaged, the X-ray unit automatically
prevents or blocks the triggering of an X-ray shot
until the necessary cooling time has passed. In
addition, a display or a warning signal informs the
operator that the thermal loading limit has been
reached.
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When the reaching of a thermal loading limit is
signaled, it is, however, possible to force further
X-ray shots even though they are blocked, in principle,
by the X-ray unit. This can be provided for medical
reasons, for example. To this end, it is known practice
to provide a separate key which an operator needs to
operate in order to release the X-ray unit's blocking
mechanism. It is then possible to use the normal shoot
key to trigger an X-ray shot as normal. The need for a
separate key to be operated is intended to ensure that
the operator is aware under all circumstances that when
forcing the X-ray shot there is the risk of damage to
the X-ray tube or to the anode plate.
To inform the operator about the loading state of an
X-ray tube, DE 100 39 416 A1 has disclosed a display
which an X-ray unit, upon reaching a loading limit,
uses to display the remaining cooling time which needs
to pass in order for the X-ray tube to cool down
sufficiently. An operator can use this time display to
optimize his working sequence, for example. In
addition, particularly in hurried cases, e.g. in
emergency diagnostics, there can be a better estimation
of whether the necessary cooling time is acceptable. On
the basis of this, the operator can better decide
whether X-ray shots need to be forced despite the
loading limit having been reached.
A drawback of the known display and control elements is
that the operator needs to direct his attention to two
different elements of the X-ray unit in order to force
X-ray shots. To detect the remaining cooling time after
the loading limit has been reached, the operator needs
to look at the cooling-time display. To release the X-
ray unit's blocking mechanism, he needs to look at the
separate, detached key for debblocking. When the
deblocking key has been operated, an X-ray shot can be
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triggered by operating the shoot key, as a third
element needing to be visualized.
Particularly with regard to X-ray units' displays,
which are becoming ever more comprehensive and full of
information, the need to devote attention to a
plurality of separate elements for one and the same
procedure is confusing, complicated and takes up an
unnecessary amount of time. When working under a high
level of strain and with a high level of time pressure,
for example in emergency medicine, this can easily
result in the information on the cooling-time display
no longer being given any attention at all. Instead, an
operator under the stress of a medical emergency
situation will readily operate the separate deblocking
key immediately upon reaching the loading limit,
without purposefully also paying attention to the
cooling-time display beforehand.
It is the object of the invention to provide an X-ray
unit having a cooling-time display and having an
deblocking key for the purpose of forcing X-ray shots
despite a thermal loading limit having been reached, in
which the deblocking key and the cooling-time display
can be detected and operated quickly and intuitively.
The invention achieves this object by means of a
display and a control element having the features of
the first patent claim.
A basic idea behind the invention involves combining
the cooling-time display and the deblocking key for
forcing X-ray shots with one another and linking them
to form a single, common break-time key. The break-time
key as a combined key and display element can
advantageously be detected at one glance and hence
quickly. In addition, the combination results in
elements with associated content also being brought
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together visually, which makes operating the X-ray unit
more intuitive and ergonomic.
In one advantageous refinement of the invention, the
break-time key is used not just for displaying the
remaining cooling time and for deblocking the next
X-ray shot but also permits immediate triggering of the
next X-ray shot in addition to the deblocking. This
makes the detection and operation of a further,
additional control element unnecessary and saves a
further control step. At the same time, the display
functionality continues to ensure that it is clear to
an operator that by triggering the X-ray shot there is
a risk of damage or destruction.
Other advantageous refinements of the invention are
covered by the dependent patent claims.
Exemplary embodiments of the invention are described in
more detail below with reference to schematic figures,
in which:
figure 1 shows an X-ray unit with a break-time key in
line with the invention,
figure 2 shows a break-time key in which the period of
time is displayed in units of time,
figure 3 shows a break-time key which displays the
period of time as a percentage,
figure 4 shows a break-time key which displays the
period of time symbolically,
figure 5 shows a control device with a break-time key.
Figure 1 schematically shows an X-ray unit 1 which, in
the case of the present exemplary embodiment, comprises
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a patient table 2 (indicated merely schematically),
which is supported by a mounting apparatus (not shown
in figure 1), and a support apparatus 3 carrying an
X-ray source 4. An X-ray image cassette 5 arranged on
the patient table 2 is used for obtaining an X-ray
image using an X-ray beam 6 which is emitted by the
X-ray source 4 and is attenuated upon passing through
an examination object 7 (shown merely schematically),
the marginal rays of said X-ray beam 6 being shown in
dashes in figure 1.
In addition, an X-ray tube (not shown in figure 1) in
the X-ray source 4 is connected to an X-ray generator 9
by means of an electric line 8. A control device 10
arranged in the housing of the X-ray generator 9 uses a
computer program to control the X-ray generator 9
during the X-ray shot such that the operational values
input using a control device 11 prior to the X-ray shot
observe a tube voltage and a quantity of electricity.
The control device 11 is arranged on a control desk 12
and is connected to the control device 10 by means of
an electric line 13. The control device 10 prevents or
blocks the triggering of X-ray shorts upon reaching a
thermal loading limit, whether as a result of an X-ray
tube's or anode plate's loading limit being exceeded or
as a result of the exceeding thereof being immediately
imminent. It is possible to ascertain that the loading
limit has been reached by measuring the temperature of
the anode or by recording the quantity of electricity
which has flowed through the X-ray tube for each time,
for example.
The X-ray unit 1 comprises an inventive break-time key
14 which is arranged on the control desk 12. The
break-time key 14 incorporates a display of the period
of time which the X-ray tube in the X-ray source 4 of
the X-ray unit 1 needs, having reached a loading limit
on account of the thermal loading of previous X-ray
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shots, to obtain a sufficient distance from the loading
limit again. The break-time key 14 also incorporates a
functionality as a key. To this end, it is
alternatively in the form of an element on a
touch-sensitive screen (touch screen), in the form of
an element on a non-touch-sensitive screen, or in the
form of a mechanical key with additional display
functionality, e.a. in the form of LEDs or LCDs. When
the break-time key 14 is operated by pressing a key,
the X-ray generator's block is lifted, which means that
the triggering of X-ray shots can be forced despite the
loading limit having been reached.
The period of time for cooling which is displayed by
the integrated break-time key 14 can be ascertained, by
way of example, using a computer (not shown in
figure 1) in which cooling curves for an anode in the
X-ray tube are stored and by measuring the temperature
of the anode.
Figures 2 to 4 show options for the design of the
cooling-time display for the break-time key 14 (which
is not shown in detail in figure 1). In this case, it
is of no matter whether the break-time key 14 is a
touchscreen element or is in another form.
The display 20 incorporated in the break-time key 14
and shown schematically in figure 2 shows the period of
time required for the X-ray tube to cool down in units
of time, that is to say the period of time until the
X-ray unit 1 shown in figure 1 is operational again.
The period of time is counted down in the manner of a
countdown. In the case of the exemplary embodiment of
the display 20 which is shown schematically in
figure 2, the period of time which still remains until
the X-ray tube is operational again is shown in minutes
and seconds. Alternatively, other units of time could
be chosen. In addition, the break-time key 14 displays
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advice 24 ("Press to lift limit") indicating that
operating it allows the block on the next X-ray shot to
be lifted.
In the case of the present exemplary embodiment, the
X-ray tube still needs three minutes and twelve seconds
until it is operational again. When the break-time key
14 has been operated, the period of time continues to
be displayed.
Figure 3 schematically shows a display 21 which is
incorporated in the break-time key 14 and displays the
period of time for the X-ray tube to cool down as a
percentage. If the display 21 displays 100%, this can
mean, by way of example, that the X-ray unit 1 has
turned off at present on account of a risk of
overheating. The percentage on the display 21 is thus a
measure of the remaining period of time in relation to
the total period of time of a cooling phase for the
X-ray tube at present. In addition, the break-time key
14 displays, as previously in figure 2, advice 24
("Press to lift limit") indicating that operating the
break-time key 14 allows the block on the next X-ray
shot to be lifted.
Figure 4 schematically shows a display 22 which is
incorporated in the break-time key 14 and displays the
period of time for the X-ray tube to cool down
symbolically. In the case of the present exemplary
embodiment, the period of time is shown using a bar 23
whose length 1 is variable. When the bar 23 is at its
maximum length lmaX, for example, this can mean, by way
of example, that the X-ray unit 1 has turned off at
present on account of a risk of overheating. The length
1 of the bar 23 is thus a measure of the remaining
period of time in relation to the total period of time
of the X-ray tube's cooling phase at present. In
addition, the break-time key 14 displays, as previously
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in figure 2 and figure 3, advice 24 ("Press to lift
limit") indicating that operating the break-time key 14
allows the block on the next X-ray shot to be lifted.
Combinations of the displays 20 - 22 and 24 for the
break-time key 14 which are shown in figures 2 to 4 and
are described are also possible. In addition, the
break-time key 14 can also be switchable between the
displays 20 - 22 and 24.
Figure 5 shows a control device 11 in line with the
invention, in this case in the form of a touchscreen.
The control device 11 displays all the elements which
can be used to select or set the operational values for
the X-ray unit 1. It has an area in which an
operational-value display 25 shows all the current
settings and an area for inputting operational values
26, said area being able to be used by an operator to
set all the operational values for the X-ray unit 1.
Settings which an operator makes in the
operational-value input 26 are immediately displayed in
the operational-value display 25. The display and
setting elements do not need any more detailed
discussion in order to explain the invention.
The operational-value display 25 also contains a
break-time key 14 in line with the invention. This is
shown symbolically as a clock in figure 5. For display
purposes, there are also other variants available,
however, e.g. those explained previously in figure 2,
figure 3 and figure 4. When the control device 10
establishes that a thermal loading limit for the X-ray
tube has been reached or is immediately imminent, the
break-time key 14 on the control device 11 is either
revealed or is visually highlighted with clarity. The
revelation or highlighting signals that the break-time
key 14 has been activated and that a thermal loading
limit has been reached. The break-time key 14 activated
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in this manner expediently has a design which makes it
clearly discernible and conspicuous, e.g. through the
use of a signal color or as a result of it flashing. It
can also be in visually enhanced form as a prominent
key. It is in a form such that an operator can
immediately recognize it despite the extreme wealth of
information on the control device 11.
By means of the symbolic display used in the form of a
clock, the break-time key 14 shows the remaining period
of time which is required in order for the X-ray tube
to cool down after it has reached a thermal loading
limit. When this cooling time has passed, the
break-time key automatically returns to the visual
background. If an X-ray shot needs to be taken before
the cooling time has passed, however, then an operator
needs to deblock this shot by operating the break-time
key 14. The X-ray shot can then be triggered in the
usual way by operating a shoot key (not shown in more
detail). The separate activation and operation of the
break-time key 14 ensure that an operator is clear
about the risk of damage to the X-ray tube as a result
of triggering an X-ray shot.
In one particular refinement of the invention,
operating the break-time key 14 not only deblocks the
next X-ray shot but also simultaneously triggers the
X-ray shot. This saves one work step for an operator,
since he does not first additionally need to visualize
and operate the shoot key.
The integration of various display and control
functionalities in the break-time key 14 thus increases
the visual order of the control device 11 and makes it
easier to operate.
