1.  Field of the Invention
The present invention relates to an ultrasonic diagnostic apparatus and its operation device.  More particularly, the present invention relates to contrivance of a dedicated suitable input device for a workflow system supporting operation of apparatus during detection or diagnosis. 
2.  Description of Related Art
Ultrasonic signals have been clinically used in various fields, and one of them is an application to an ultrasonic diagnostic apparatus.  The ultrasonic diagnostic apparatus acquires an image signal through transmission and reception of an ultrasonic signal toward and from a subject and is used in a variety of modes utilizing non-Invasiveness of the signal.  One typical type of ultrasonic diagnostic apparatus produces tomographic images of a soft tissue of a living body by adopting ultrasonic pulse reflection imaging.  This imaging method is noninvasive and produces a tomographic image of the tissue.  Compared with other medical modalities such as diagnostic X-ray imaging, X-ray CT imaging, MRI, and diagnostic nuclear medicine imaging, the imaging method has many advantages: real-time display is possible, a compact and relatively inexpensive apparatus can be constructed, patient exposure of X-rays or the like will not occur, and blood imaging is possible thanks to ultrasonic Doppler imaging.  The imaging method is therefore most suitable for diagnosis of the heart, abdomen, mammary gland, and urinary organs, and for diagnosis in obstetrics and gynecology.  In particular, pulsation of the heart or motion of a fetus can be observed in real time through simple manipulation that in as simple as placing ultrasonic probe on a patient""s surface.  Moreover, since patient exposure need not be cared about, screening can be carried out many times repeatedly.  Furthermore, there is an advantage that an apparatus can be moved to a bedside position for ready screening. 
For screening the heart or abdominal organs, contrast echo imaging has newly been introduced and spotlighted, by which an ultrasonic contrast medium is trans-venous injected into a patient for evaluating the kinetics of blood flow.  Since trans-venous injection of a contrast medium is less invasive than trans-arterial injection, the method is becoming popular.  The main component of the contrast medium is micro-bubbles that act as a source of reflection of ultrasonic waves.  The larger the amount and concentration of injected contrast medium is, the larger the effect of contrast imaging is.  However, since the bubbles are crushed due to irradiation of ultrasonic waves, the time during which the effect of contrast imaging persists is shortened.  Although a contrast medium characteristic of high persistency and high durability against sound pressure has been developed in recent years, the long-term persistence of the contrast medium in a human body predictably raises invasiveness. 
Since the life of contrast medium is transitory as described above, examination time of contrast echo imaging is limited.  Consequently, compared with an examination without a contrast medium, assistance is necessary for works such as manipulation of the apparatus, preparation and injection of a contrast medium, and control of examination time, which necessitates more manpower.  And due to the limited examination time, sequential examination procedure (examination scenario) of contrast echo imaging as a routine examination is fixed, and it is necessary to execute the examination scenario smoothly. 
Concerning this issue, proposed is an ultrasonic diagnostic apparatus mounting xe2x80x9cworkflow systemxe2x80x9d (also called Intelligent Assistant System: IASSIST) which displays examination procedure in accordance with an examination plan, in order to carry out a menu item included in the displayed examination procedure with one switch action, retrieves small program correspondent with each menu item (also called xe2x80x9cactivityxe2x80x9d) and implements this program (ref: Japanese Patent Application KOKAI Publications No.2001-137237). 
With the use of the workflow system, examination procedure is guided and switching operation is simplified, so that the efficiency of examination is raised and mistakes of examination are reduced.  its effect become remarkable particularly in the examination such as of the contrast echo imaging. 
However, in the ultrasonic examination, especially observing dynamic kinetics of blood flow with contrast medium an operator such as a doctor or a technician should hold an ultrasonic probe touched to a subject (patient) in order to maintain the same region of interest, consequently, switching operation to the apparatus under such a circumstance forces the operator to bear the physical burden.  In addition, as the operator needs to turn one""s gaze on a switch on a control panel (such as a console and an operation panel) to carry out switching operation, the aimed region of interest is often missing and needs adjusting anew.  It means a waste of time. 
The above described ultrasonic diagnostic apparatus with workflow system surely simplifies a complicated sequential switching operation, but it was not invented in consideration of the above operator""s circumstances, it still requires switching operation on the part of the main frame of the apparatus.  In regard to this point, it stays unchanged from the conventional one. 
The present invention has been made in view of the described circumstances in the prior art.  It is an object of the present invention to provide an ultrasonic diagnostic apparatus and an operation device for optimizing the advantage of the workflow system (also called Protocol Assistant System: PAS, however for the convenience of explanation, hereinafter abbreviated to WFS) so that a doctor or a technician, who operates an ultrasonic diagnostic apparatus while the workflow system is on and scans with an ultrasonic probe, especially may be relieved from the physical and mental stress, concentrate on images and diagnose efficiently. 
The above described workflow system has the advantage of guiding an examination procedure, reducing the number of times of switching operation, such as a change-over of modes and a setting of conditions on images, to a few times or one, and proceeding with a series of examination smoothly.  By taking this advantage, the operation may be done at hand without reaching out to a control panel installed to the ultrasonic diagnostic apparatus daringly
A further object of the present invention is to provide a dedicated input device as a means for improving the function of the workflow system further, especially a small remote control input device with bare essentials of switches necessary to operate the workflow system.  The present invention is accomplished based on the above idea. 
In order to achieve the foregoing object, as one aspect of the invention, there is provided an ultrasonic diagnostic apparatus comprising: an ultrasonic diagnostic apparatus comprising: a main frame configured to produce an ultrasonic Image using a signal detected by an ultrasonic probe; and an operation device configured to remote-control an operation of the main frame, wherein the operation device comprises a button adopted to specify a function necessary for the operation of the main frame and a processing circuit configured to carry out processing necessary for obtaining the function. 
Preferably, the operation device is formed into a portable type or a detachable type of operation device or may be configured to communicate by radio waves with the mainframe. 
It is preferred that the ultrasonic diagnostic apparatus further comprises control means configured to switch the operation of the main frame by sequentially executing a plurality of execution items in accordance with the work procedure which predetermines an execution sequence of a plurality of execution items or in addition to the above, further comprises to alter the execution sequence of the execution items in compliance with the operation of the operation device. 
It is also preferred the ultrasonic diagnostic apparatus further comprises generating means configured to generate a display image by means of combining at least one of icons and letter strings which are allocated to the plurality of the execution items executed by the control means and ultrasonic image generated from the signals received by the ultrasonic probe. 
Further preferably, the operation device comprises execution buttons and shift buttons which give predetermined control commands to the control means by an operation of an operator, the execution means selects at least one of the plurality of the execution items when receiving the control command given by the shift button, and executes at least one of the plurality of the execution items selected by the operation of the shift button when the control command is received, the generating means has changing means for changing the display status of at least one of the icons and the letter strings in order to visually grasp on the display at least one of the execution items selected by the operation of the shift button.  Or the operation device further comprises a change-over button switching the operation concerning the work sequence and the operation concerning the main frame each other is configured to communicate by radio waves with the main frame, the control means further comprises the control means for controlling and allocating at least one of switching functions set in the main frame to switches on the operation device so that the switching function may be executed by the operation device. 
Still preferably, the buttons are specialized to the selected functions, the selected function is a function to freeze an ultrasonic image, the ultrasonic diagnostic apparatus further comprises a plurality of buttons which are specialized to one of the functions to freeze, printout and store an ultrasonic image, the function of each button is customized to the function frequently used in diagnosis with the ultrasonic diagnostic apparatus, or the function of each button is allowed individually by each operator to be customized, stored, and recalled. 
It is also preferred the operation device further comprises a vibration mechanism having a driving circuit which works when a predetermined control command is received, and the control means further comprises communicating means for giving the control command to the operation device so that the vibration mechanism vibrates, or further comprises a loudspeaker outputting voice when a predetermined control command is received, and the control means further comprises communicating means for giving the control command to the operation device so that the loudspeaker outputs voice both in case where at least one of predetermined conditions are met, the predetermined conditions including a change-over of a contrast echo mode set in the ultrasonic diagnostic apparatus, elapsing of an predetermined alarm time, and finding of an unusual electrocardiographic condition of a patient.  Or it is still preferred the operation device further comprises a microphone receiving voice including the operator""s diagnostic observation, and the control means further comprises recording means for recording the voice when the operator""s diagnostic observation is provided. 
As another aspect of the present invention, there is an operation device used for the ultrasonic diagnostic apparatus comprising a main frame configured to produce an ultrasonic image using a signal detected by the ultrasonic probe and to be remote-controlled by the operation device, the operation device comprising: a button adopted to specify a function necessary for the operation of the main frame and a processing circuit configured to carry out processing necessary for obtaining the function,
Preferably, the operation device further comprises: an LED display indicating both a residual quantity of a battery for power supply and a communication status with the main frame; and the processing circuit executing necessary procedure to distinctively indicate at least one of a lack of the residual quantity of the battery, a waiting status and an established status of the communication, or liquid crystal screen displaying at least a menu and present status of the operation of the operation device; and the processing circuit executing a necessary procedure to display the present status of the operation of the operation device on the screen.