Patent Publication Number: US-2020275908-A1

Title: Ultrasonic probe and ultrasonic measurement system

Description:
TECHNICAL FIELD 
     The presently disclosed subject matter relates to an ultrasonic probe and an ultrasonic measurement system. 
     BACKGROUND ART 
     Ultrasonic diagnostic apparatuses are widely used for checking a condition of a chest, an abdomen, etc. of a subject. The ultrasonic diagnostic apparatuses configured to cause an ultrasonic beam enter a body of the subject through a probe head of an ultrasonic probe, and processes a reflected wave of the ultrasonic beam to thereby display an ultrasonic image (e.g., a tomographic image inside the body or a blood flow image). When displaying the image, an abutment position, an abutment angle etc. of the probe head are recorded. When this record is absent, the abutment position, the abutment angle, etc. of the probe head may be then unclear to thereby make diagnosis difficult. 
     To solve this problem, in a general ultrasonic diagnostic apparatus, a body mark (a kind of icon) is displayed together with an ultrasonic image on a screen. The body mark is a schematic diagram illustrating the abutment position or an abutment direction of the probe head. The body mark is stored in association with the ultrasonic image. The body mark is usually input or set manually by an operator before or after imaging. 
     However, when the operator changes the abutment position or the abutment angle, the operator has to input the body mark. Such an operation burden is large. In addition, there is also a problem that it is difficult to know which direction the image was captured from, based on information of only the body mark. 
     An ultrasonic diagnostic apparatus according to a first related art (see, e.g., JP2006-000400A) has a video camera taking an image of a subject and an ultrasonic probe and displays an image in which an ultrasonic image and the image of the video camera have been combined. Thus, it is possible to grasp information about an abutment region or an abutment angle without performing an input work for a body mark. 
     A second related art (see, e.g., JP2005-058577A) also has a configuration similar to the first related art, i.e., a configuration in which an imaging device is provided to capture an image of an ultrasonic probe. 
     According to a third related art, an ultrasonic image is displayed together with various vital signs on a patient monitor (see, e.g., WO2009/138902A1). In the configuration, the patient monitor is configured to be detachably attached to an ultrasonic probe. The patient monitor displays the ultrasonic image together with information of the vital signs (e.g., blood pressure, a pulse, a respiration rate, body temperature, etc.). In the configuration, the ultrasonic probe is inserted into a connector insertion port of the patient monitor so that ultrasonic diagnosis can be made simply (see, e.g., FIG. 1 of WO2009/138902A1). 
     However, in the third related art, there is no suggestion or instruction about a body mark. Accordingly, a manual input burden is large when the body mark is used. 
     The first related art and the second related art have a configuration in which the imaging device (the apparatus imaging the ultrasonic probe) is provided to have a separate housing from that of the ultrasonic diagnostic apparatus (see, e.g., FIG. 1 of JP2006-000400A and FIG. 1 of JP2005-058577A). That is, the ultrasonic probe, the apparatus (the ultrasonic diagnostic apparatus) processing a signal acquired from the ultrasonic probe and displaying the processed signal, and the imaging device are provided separately. However, since the patient monitor is assumed to be used at various scenes, it may be difficult to provide the imaging device having the separate housing. 
     For example, in a case where an ultrasonic image is desired to be referred to with the patient monitor being used in an operating room, the degree of spatial freedom is significantly impaired if a body mark imaging device is also provided in the operating room having a large physical limitation. Even when the ultrasonic probe is desired to be connected to the patient monitor only if the occasion demands, the imaging device has to be additionally provided. 
     The first related art and the second related art assume that the imaging device is fixed at a place to capture a photographic image. Accordingly, an image of the probe head may not be captured properly and an abutment state of the probe head may not be grasped accurately. 
     This problem (the impairment of the degree of spatial freedom due to the provision of the imaging device) is not limited to the case where the patient monitor supporting the ultrasonic image is used in the operating room, but is a problem common to a case where the ultrasonic probe is used in connection with the patient monitor. Also in a case where the ultrasonic probe is connected to a tablet type personal computer, there is a need that an abutment state of the probe head is desired to be grasped. The impairment of the degree of spatial freedom due to the arrangement of the imaging device at a fixed point is desirably avoided also in the case where the tablet type personal computer is used. 
     SUMMARY OF INVENTION 
     Illustrative aspects of the presently disclosed subject matter provide an ultrasonic probe and an ultrasonic measurement system in which an abutment state of a probe part (probe head) of the ultrasonic probe can be grasped properly in a simple configuration when the ultrasonic probe is used in connection with an apparatus displaying an ultrasonic image. 
     According to an aspect of the presently disclosed subject matter, an ultrasonic probe is provided. The ultrasonic probe is electrically connectable to a display device configured to display an ultrasonic image. The ultrasonic probe includes an image capturing unit joined to or detachably attached to a first cable, the image capturing unit comprising a first optical lens to capture an image of a nearby object, and a probe head joined to or detachably attached to the first cable, the probe head being configured to transmit an ultrasonic beam toward a body surface of a subject and to receive a reflected wave from the body surface. 
     With this configuration, the image capturing unit is configured to capture an image of the nearby object, and is connectable to the probe head through the first cable. Thus, the image capturing unit can capture an image of the probe head from a distant position. A user can hold and move the image capturing unit to capture an image of an abutment state of the probe head. In addition, the image capturing unit and the probe head are integrated with each other through the first cable. Since the image capturing unit and the probe head are integrated with each other, it is possible to capture an image of a condition of a nearby object during ultrasonic diagnosis without providing a separate imaging device. That is, even at a place with a large physical limitation, it is possible to perform ultrasonic measurement while grasping the abutment state of the ultrasonic probe in a simple configuration. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a view of an ultrasonic probe and a patient monitor according to an embodiment of the presently disclosed subject matter. 
         FIG. 2  is another view of the ultrasonic probe. 
         FIG. 3A  is a view of an image capturing unit of the ultrasonic probe. 
         FIG. 3B  is another view of the image capturing unit. 
         FIG. 4A  is a view of a probe head of the ultrasonic probe. 
         FIG. 4B  is another view of the probe head. 
         FIG. 5  is a view illustrating an example of how the ultrasonic probe is to be used. 
         FIG. 6  is a view of another example of the ultrasonic probe. 
         FIG. 7A  is a view of another example of the image capturing unit. 
         FIG. 7B  is another view of the image capturing unit of  FIG. 7A . 
         FIG. 8  is a view illustrating another example of how the ultrasonic probe is to be used. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments of the presently disclosed subject matter will be described below with reference to the drawings.  FIG. 1  is a view of an ultrasonic measurement system  1 . The ultrasonic measurement system  1  includes an ultrasonic probe  10  and a patient monitor  20  connected to the ultrasonic probe  10 . The patient monitor  20  is configured to measure various vital signs based on vital sign signals acquired by various sensors (not illustrated in  FIG. 1 ). The sensors may include, for example, a cuff used for measurement of blood pressure, electrodes (such as disposable electrodes, clip electrodes, etc.) used for measurement of an electrocardiogram etc., an SpO2 probe, a mask used for measurement of respiration, etc. The vital signs may include, for example, body temperature, the blood pressure, the electrocardiogram, respiration information (a respiration rate, a respiration waveform), SpO2 (arterial oxygen saturation), a heart rate, etc. The number of the vital signs to be measured by the patient monitor  20  or the number of the sensors to be connected to the patient monitor  20  may be set desirably. The patient monitor  20  is a concept that can be interpreted to correspond to various medical apparatuses for measuring the various vital signs, such as a bedside monitor, a wearable medical telemeter, a defibrillator including a measurement function of the electrocardiogram etc., etc. In the following description, assume that the patient monitor  20  is a so-called bedside monitor. 
     The patient monitor  20  can be electrically connected to (can transmit/receive an electronic signal to/from) the ultrasonic probe  10  in addition to the aforementioned various sensors. When a connector of the ultrasonic probe  10  is inserted into a connector insertion port of the patient monitor  20  in the configuration of  FIG. 1 , the ultrasonic probe  10  is electrically connected to the patient monitor  20 . The ultrasonic probe  10  abuts on a body surface of a subject, transmits an ultrasonic beam toward the body surface, and receives a signal representing a reflected wave from the body surface. The ultrasonic probe  10  supplies the reflected wave signal to the patient monitor  20 . The ultrasonic probe  10  may supply the reflected wave signal directly to the patient monitor  20 , or may perform various signal processings on the reflected wave signal and supply ultrasonic image data created thus to the patient monitor  20 . That is, the ultrasonic probe  10  supplies the image information about the ultrasonic wave to the patient monitor  20 . 
     The patient monitor  20  has a display that displays measured values and measured waveforms of the various vital signs, as illustrated in  FIG. 1 . The waveforms of the vital signs in the patient monitor  20  may be analyzed or displayed by a generally used method. In addition, the patient monitor  20  displays an ultrasonic image of the subject on the display based on the reflected wave signal (or the ultrasonic image data) received from the ultrasonic probe  10 . That is, the patient monitor  20  has a configuration in which ultrasonic image displaying software can be installed into the patient monitor  20 . Specifically, the patient monitor  20  includes various storage devices (a hard disk, an RAM, an ROM, etc.) configured to store the software, a central processing unit (CPU) configured to read and execute data (including the software) from the storage devices, etc. 
     The patient monitor  20  may display the ultrasonic image together with the measured values or the measured waveforms of the vital signs or may display only the ultrasonic image. In addition, the patient monitor  20  displays a photographic image (a still image or a moving image) captured by an image capturing unit  12  on the display. The image capturing unit  12  will be described later. The patient monitor  20  properly records the ultrasonic image or the photographic image on an internal recording device (e.g., the hard disk). 
     The patient monitor  20  may detect characteristics (an output frequency, output intensity, a probe type, etc.) of the ultrasonic probe  10  based on at least one of a color and a shape of a marker  111  (that will be described later) of a probe head  11 . The detection will be described later with reference to  FIG. 5 . 
     When a control signal for instructing a change of settings (e.g., alarm cancellation, activation of one of various applications, etc.) is input to the patient monitor  20  from the ultrasonic probe  10 , the patient monitor  20  changes the setting of the patient monitor  20  itself or activates the application in accordance with the control signal. An electric circuit and/or a program for processing the input of the control signal may be provided in the patient monitor  20 . 
     Next, a housing configuration of the ultrasonic probe  10  will be described with reference to  FIG. 2 . The ultrasonic probe  10  has the probe head  11 , the image capturing unit  12 , a cable  13  (first cable), a cable  14  (second cable), and a connector  15 . The cable  13  and the cable  14  may have optional lengths respectively. The cable  13  and the cable  14  can be bent flexibly. 
     The probe head  11  abuts on a body surface of a subject (i.e. makes contact with the body surface of the subject or is sufficiently close to the body surface of the subject), transmits an ultrasonic beam on the body surface of the subject, and receives a reflected wave of the ultrasonic beam from the body surface of the subject. The probe head  11  may be of a sector type, a convex type, a linear type or any other type. The probe head  11  is installed with various electric circuits and the like to control an ultrasonic frequency, beam forming, mode switch (e.g., switching among a B mode, an M mode and a D mode), contrast, depth, an imaging gain, etc. The probe head  11  supplies an image signal based on the reflected wave to the patient monitor  20  through the cable  13  and the cable  14 . 
     The configuration of the image capturing unit  12  will be described with reference to  FIGS. 3A and 3B  in addition to  FIG. 2 .  FIG. 3A  is a conceptual diagram in which an operating face of the image capturing unit  12  is viewed as a front face (the face where input interfaces that will be described later are provided is viewed as the front face).  FIG. 3B  is a conceptual diagram in which the image capturing unit  12  is viewed from a side. Description will be made on the assumption that a short axis direction, a long axis direction and a depth direction in the front view and the side view of the image capturing unit  12  in  FIGS. 3A and 3B  are expressed as X-axis direction, Y-axis direction and Z-axis direction respectively. A user holds the image capturing unit  12  so as to pinch the image capturing unit  12  from a +Z direction and a −Z direction though not always limited thereto. More specifically, the user presses the image capturing unit  12  by a thumb from the +Z direction and presses the image capturing unit  12  by fingers other than the thumb from the −Z direction. 
     The image capturing unit  12  has an optical lens  121  (first optical lens in  FIG. 3B ) for capturing an image of a nearby object. A position where the optical lens  121  is disposed is not limited particularly, but is located on an upper portion side of a long-axis face disposed in the −Z direction (a +Y side, in other words, a side far from a face to which the cable  13  and the cable  14  are connected when the long axis (the length in the Y-axis direction) of the image capturing unit  12  is divided into two). The optical lens  121  may be an optical lens suitable for taking a moving image or a still image, or an optical lens similar to or the same as that provided, for example, in a smartphone etc. 
     The various input interfaces are provided on a housing of the image capturing unit  12 . In the example of  FIGS. 3A and 3B , a power button  122 , input buttons  123 , a scroll wheel  124  are provided on the long-axis face in the +Z direction. The power button  122  is a button for controlling ON/OFF of the image capturing unit  12 . The input buttons  123  are used for instructing start or stop of imaging. The scroll wheel  124  is also used for instructing start or stop of imaging in a similar manner to or the same manner as the input buttons. 
     The input interfaces in  FIGS. 3A and 3B  are merely examples. The number of the buttons or the positions where the buttons are disposed are not particularly limited. The input interfaces (the power button  122 , the input buttons  123  and the scroll wheel  124 ) may be provided on a side opposite to the side on which the optical lens  121  is provided, as illustrated in  FIG. 3B . With this configuration, it is possible to stop imaging or issue an instruction etc. to the probe head  11  that will be described later even during the imaging without touching the optical lens  121  (in other words, without interrupting the imaging). The image capturing unit  12  may have a configuration in which some of the input interfaces are provided on one or each of the side faces. 
     Although not essential, the image capturing unit  12  may be configured to have the optical lens  121  and other optical lenses. In the configuration in  FIG. 3A , an optical lens  125  is provided on the long-axis face in the +Z direction. Thus, it is possible to image not only an abutment state of the probe head  11  but also information of a person who is engaging in the imaging, etc. 
     The image capturing unit  12  has an internal configuration equivalent to a general digital still camera. For example, the image capturing unit  12  has input/output interfaces, various circuits (an analog signal processing circuit, an A/D converter, a digital signal processing circuit, an image inputting controller, etc.), various storage devices (a random access memory (RAM), a read only memory (ROM), etc.), a central processing unit (CPU) or a micro processing unit (MPU), a diaphragm, a diaphragm actuator, etc. The image capturing unit  12  applies photoelectric conversion etc. to light that has passed through the optical lens  121  and the diaphragm to thereby create an image signal (a signal indicating a photographic image). The image capturing unit  12  may be configured to perform various image processings (e.g., white balance processing) etc. The image capturing unit  12  transmits the image signal to the patient monitor  20  through the cable  14 . 
     The image capturing unit  12  may act as a remote controller that transmits a control signal to at least one of the patient monitor  20  and the probe head  11 . For example, the image capturing unit  12  may transmit, to the probe head  11 , a control signal for instructing change of the ultrasonic frequency, change of the beam forming setting, the mode switch (e.g., among the B mode, the M mode and the D mode), the contrast, the depth, the imaging gain, etc. in accordance with operation on the input interfaces (the input buttons  123  or the scroll wheel  124 ). The image capturing unit  12  may transmit, to the patient monitor  20 , a control signal for instructing alarm cancellation, display setting, activation of an application etc. in accordance with operation on the input interfaces. That is, the image capturing unit  12  is configured to transmit a control signal for instructing a change of settings to at least one of the patient monitor  20  and the probe head  11  in accordance with an operation on the input interfaces provided on the housing. Upon receipt of the control signal as the input, the probe head  11  changes the settings in accordance with the control signal. To transmit the control signal to the probe head  11 , the image capturing unit  12  may transmit the control signal via the patient monitor  20 . 
     The image capturing unit  12  is connected to the cable  13  and the cable  14  ( FIG. 3A ). The cable  13  may be joined to the image capturing unit  12  (in other words, the cable  13  may be fixed to the image capturing unit  12  such that the cable  13  cannot be inserted into or removed out of the image capturing unit  12 ). Alternatively, the image capturing unit  12  and the cable  13  may be configured to be detachably attached to each other. That is, the image capturing unit  12  is joined to or detachably attached to the cable  13 . The image capturing unit  12  has the optical lens  121  to capture an image of a nearby object. 
     In a similar manner or the same manner, the cable  14  may be joined to the image capturing unit  12 , or the image capturing unit  12  and the cable  14  may be configured to be detachably attached to each other. 
     It is desirable that a connection place of the cable  13  and a connection place of the cable  14  are located in the same face, as illustrated in  FIG. 3B . In addition, it is preferable that the optical lens  121  is disposed on the face different from (another face than) the face where the cable  13  and the cable  14  are connected. In the example of  FIG. 3B , the cable  13  and the cable  14  extend from the side facing in a −Y direction. That is, an extension direction of the cable  13  and an extension direction of the cable  14  are substantially the same, and the cable  13  and the cable  14  extend in the direction (the −Y direction) that is different from an imaging direction (the −Z direction) of the optical lens  121 . The cable  13  and the cable  14  are connected to the image capturing unit  12  at positions separated from the optical lens  121 . The user typically holds the image capturing unit  12  such that the optical lens  121  is on an upper side (an anti-gravitational side). Therefore, when the user holding the image capturing unit  12  captures a photographic image, the cable  13  and the cable  14  extend in the gravity direction so that the cable  13  and the cable  14  can be prevented from easily entering the imaging range of the optical lens  121 . That is, the cable  13  and the cable  14  are connected to the face (the side facing in the −Y direction) different from the face (the side facing in the −Z direction) where the optical lens  121  is disposed. Thus, reflection of the cable  13  and the cable  14  on the photographic image can be prevented. The face (the side facing in the −Y direction) where the connection place of the cable  13  and the connection place of the cable  14  are disposed does not have to be a planar face but may be a slightly round curved face alternatively. 
     A relation between the cables  13   14  and the optical lens  121  will be further described. When the optical lens  121  is oriented in a substantially horizontal direction (the −Z direction), i.e., in a direction substantially parallel to a ground surface, the cable  13  and the cable  14  extends substantially in the gravity direction (the −Y direction). Thus, an angle formed between the imaging direction of the optical lens  121  and the extension direction of the cable  13  and the cable  14  is sufficiently large, and the extension direction of the cable  13  and the cable  14  is substantially the gravity direction. Accordingly, the cable  13  and the cable  14  can be prevented from being captured in an image during imaging. 
     When the optical lens  121  is viewed from the front (when the image capturing unit  12  is viewed from the −Z direction), the cable  13  and the cable  14  are connected to the image capturing unit  12  such that the cable  13  and the cable  14  are arranged one behind the other in the depth direction (in the Z-axis direction) to be. Since the cable  13  and the cable  14  extend from the image capturing unit  12  such that they are arranged one behind the other in the depth direction, the cable  13  and the cable  14  can be prevented from being obstacles to operation (in other words, easy to handle) when the user holds the image capturing unit  12 . 
     Next, the configuration of the probe head  11  will be described with reference to  FIG. 2  and  FIGS. 4A and 4B .  FIG. 4A  is a front view of the probe head  11 .  FIG. 4B  is a side view of the probe head  11 . In  FIGS. 4A and 4B , a short axis direction, a long axis direction and a depth direction of the probe head  11  represent the X-axis direction, the Y-axis direction and the Z-axis direction respectively. The user typically holds the probe head  11  so as to pinch the probe head  11  from the −Z direction and the +Z direction. 
     The probe head  11  may have a shape or a configuration similar to or the same as that of a probe head used for ordinary ultrasonic measurement. It is preferable that the probe head  11  has the marker  111  according to which the left and the right can be grasped, as illustrated in  FIGS. 4A and 4B . Any marker can be used as the marker  111  as long as the left and right of the probe head  11  can be identified according to the marker. The shape of the marker  111  and the number of markers  111  may be set desirably. Any marker can be used as the marker  111  as long as an upper portion and a lower portion of the probe head  11  can be grasped according to the marker. That is, any marker can be used as the marker  111  as long as an abutment direction of the probe head  11  on the body surface of the subject can be recognized according to the marker. When a photographic image of the probe head  11  captured by the image capturing unit  12  is referred to, the user refers to the position of the marker  111  inside the photographic image. The user can more accurately determine how the probe head  11  has abutted on the body surface of the subject according to the reference position of the marker  111 . 
     The marker  111  may have the color or shape corresponding to the characteristics (for example, the output frequency, the output intensity, the probe type such as convex, linear, sector, etc.) of the ultrasonic probe  10 . For example, when the frequency that can be output is lower than 2.5 MHz, the marker  111  may be blue. When the frequency that can be output is not lower than 2.5 MHz, the marker  111  may be red. 
     The probe head  11  has an abutment face  112  abutting on the subject. The abutment face  112  abuts on the body surface of the subject and transmits an ultrasonic beam thereon. The abutment face  112  receives a reflected wave from the body surface of the subject. The probe head  11  supplies a signal of the reflected wave to the patient monitor  20  through the cable  13  and the cable  14 . The probe head  11  may apply signal processing to the reflected wave signal to thereby create ultrasonic image data, and transmit the ultrasonic image data to the patient monitor  20 . The probe head  11  includes various electric circuits inside the probe head  11  to transmit the ultrasonic beam and also to receive the reflected wave of the ultrasonic beam. 
     The cable  13  is a flexible cable through which the image capturing unit  12  and the probe head  11  are connected to each other. The cable  13  transmits an electric signal between the image capturing unit  12  and the probe head  11 . 
     The cable  14  is a flexible cable through which the image capturing unit  12  and the patient monitor  20  are connected to each other. The cable  14  transfers an electric signal between the image capturing unit  12  and the patient monitor  20 . The other end of the cable  14  is connected to the connector  15 . The connector  15  is inserted into a vacant slot (connection port) of the patient monitor  20  to be thereby connected to the patient monitor  20 . It is desirable that the connector  15  has a universal shape that can be inserted into a general patient monitor  20 . The cable  14  is connected to the connector  15 , and joined to or detachably attached to the image capturing unit  12 . 
     Next, an example of how the ultrasonic probe  10  is to be used will be described with reference to  FIG. 5 .  FIG. 5  is a conceptual diagram illustrating a use form in which the ultrasonic probe  10  is connected to a wall hanging type patient monitor  20 . The configuration of  FIG. 5  is merely an example. It is a matter of course that the patient monitor  20  may be of any other type than the wall hanging type. 
     A nurse N holds the image capturing unit  12  by her/his left hand, and holds the probe head  11  by her/his right hand. The image capturing unit  12  is connected to the patient monitor  20  through the cable  14 . The probe head  11  is connected to the image capturing unit  12  through the cable  13 . 
     The nurse N places the probe head  11  in contact with a body surface in the vicinity of an abdomen of a subject P to thereby perform ultrasonic measurement thereon. At the same time, after validating (turning ON) an imaging function of the image capturing unit  12 , the nurse N captures a photographic image by the optical lens  121  (not illustrated in  FIG. 5 ) oriented toward the probe head  11 . That is, the image capturing unit  12  is configured to be able to capture a photographic image (may be a moving image or may be a still image) of a nearby object. Preferably, the image capturing unit  12  capture a photographic image of an abutment state of the probe head  11 . 
     A reflected wave signal acquired by the probe head  11  is supplied to the patient monitor  20  through the cable  13  and the cable  14 . Ultrasonic image data may be alternatively supplied to the patient monitor  20  after the reflected wave signal has been converted into the ultrasonic image data. The image capturing unit  12  supplies the photographic image (the moving image or the still image) to the patient monitor  20  through the cable  14 . 
     The patient monitor  20  displays an ultrasonic image  21  (an abdominal echo image in this example) of the subject P on the display based on the supplied reflected wave signal (or ultrasonic image data). The patient monitor  20  also displays, on the display, the photographic image  22  (the moving image or the still image) acquired by the image capturing unit  12  in place of a body mark. The display example in  FIG. 5  is merely an example, and the display form may be set desirably. The nurse N may optionally select a preferred mode to display only the ultrasonic image  21  or to display only the photographic image  22 . The patient monitor  20  may also display measured values (e.g., blood pressure values) or measured waveforms of vital signs acquired by the not-shown sensors. The photographic image  22  is treated equivalently to a body mark image used in a general ultrasonic measurement apparatus. The nurse N does not have to perform an operation of inputting the body mark but can refer to the photographic image  22  equivalent to the body mark only by pointing the optical lens  121  of the image capturing unit  12  at a direction where the probe head  11  is present. 
     It is desirable that the patient monitor  20  displays the ultrasonic image  21  and the photographic image  22  and records them on the built-in hard disk etc. in association with time information. For example, the patient monitor  20  may record the ultrasonic image  21  or the photographic image  22  in association with the time information in a form of a digital imaging and communication in medicine (DICOM). 
     The nurse N may operate the input interfaces (the buttons etc.) of the image capturing unit  12  to issue an instruction for mode change about an ultrasonic wave, adjustment of the image quality, etc. The nurse N grasps the condition with reference to the ultrasonic image  21 , and operates the image capturing unit  12  (operates the input interfaces) to adjust the gain, depth, contrast, frequency etc. during the ultrasonic measurement if necessary. The image capturing unit  12  transmits a control signal for instructing a change of settings (change of the depth or frequency) to the probe head  11 . In a similar manner or the same manner, the nurse N may operate the image capturing unit  12  (operate the input interfaces) to perform the setting change (e.g., alarm cancellation) of the patient monitor  20 . The image capturing unit  12  transmits the control signal to the patient monitor  20  in accordance with an input instruction for the alarm cancellation etc. By referring to a large screen of the patient monitor  20 , the nurse N can accurately grasp the ultrasonic image  21  or the photographic image  22  and change the setting of the probe head  11  or the patient monitor  20  based on the accurately grasped information. In addition, the nurse N operates the image capturing unit  12  on hand to change the setting. Accordingly, while continuing to capture a photographic image, the nurse N can change the setting of the probe head  11  or the patient monitor  20  without taking eyes off the display of the patient monitor  20 . The setting change of the optical lens  121  may be performed properly in accordance with operation on the input interfaces. 
     It is preferable that the image capturing unit  12  is configured to be able to transmit the control signal to each of the patient monitor  20  and the probe head  11 . However, the image capturing unit  12  may be alternatively configured to transmit the control signal to one of the patient monitor  20  and the probe head  11 . 
     Next, actions of the vital signal information monitor  20  when the marker  111  has the color or the shape corresponding to the characteristics of the ultrasonic probe  10  will be described. The patient monitor  20  may analyze at least one of the color and the shape of the marker  111  reflected inside the photographic image  22 , and detect the characteristics of the ultrasonic probe  10  (the output frequency, the output intensity, the probe type (convex, linear, sector, etc.), etc.). The patient monitor  20  may store a table etc. showing the relation between the color or shape of the marker  111  and the characteristics of the ultrasonic probe  10  in advance so that the patient monitor  20  can detect the characteristics of the ultrasonic probe  10  based on the information obtained from the photographic image  22  based on the image analysis and the table. The patient monitor  20  may display the detected characteristics of the ultrasonic probe  10  on the display or write the detected characteristics of the ultrasonic probe  10  on the internal data storage device (e.g., the hard disk). 
     The configuration of the ultrasonic probe  10  is not limited to the one illustrated in  FIG. 2 . The ultrasonic probe  10  may be alternatively configured in such a manner that no cable  14  extends from the image capturing unit  12 , as illustrated in  FIG. 6 . That is, the image capturing unit  12  and the patient monitor  20  may transmit and receive data by a wireless connection function (e.g., a short range wireless communication function). The ultrasonic probe  10  may be configured to be able to transmit/receive an electric signal to/from (configured to be able to be electrically connected to) the patient monitor  20 , or may be connected to the patient monitor  20  by wire or by wireless. In a similar manner or the same manner, the probe head  11  and the patient monitor  20  may transmit and receive data by the wireless connection function (e.g., the short range wireless communication function). The probe head  11  may transmit data to the image capturing unit  12  by wire, and only the image capturing unit  12  may transmit and receive data to and from the patient monitor  20  by wireless. The ultrasonic probe  10  illustrated in  FIG. 6  has a configuration in which the image capturing unit  12  and the probe head  11  are connected to each other through the cable  13 . The cable  13  and the image capturing unit  12  may be joined to or detachably attached to each other. In a similar manner or the same manner, the cable  13  and the probe head  11  may be joined to or detachably attached to each other. The configuration of the image capturing unit  12  may be similar to or the same as that illustrated in  FIGS. 3A and 3B . The configuration of the probe head  11  may be similar to or the same as that illustrated in  FIGS. 4A and 4B . 
     In a similar manner or the same manner, the configuration of the image capturing unit  12  is also not limited to the configuration illustrated in  FIGS. 3A and 3B . The image capturing unit  12  may have a configuration in which the connection place of the cables  13 ,  14  can be changed optionally according to a use environment.  FIGS. 7A and 7B  illustrate a configuration in which the connection place of the cables  13 ,  14  can be changed optionally. In order to make it easy to understand, positions of slots  16  to  18  each representing a connection port for the cable  13  or the cable  14  are indicated by a dot line in  FIG. 7B . 
     The image capturing unit  12  has the slots (connection ports) provided on a side in the −Y direction and a side in the +Y direction so that one of the slots (connection ports) is connected to the cable  13 . That is, the image capturing unit  12  has three or more slots connectable to (detachably attached to) the cable  13  or the cable  14 . For example, each of the slots may be an insertion port for a universal serial bus (USB) cable. The user attaches the cable  13  and/or the cable  14  to the image capturing unit  12  in accordance with a use condition, and places the cable  13  or the cable  14  at a most suitable position. That is, the user manually can change a connection state from the connection state in  FIGS. 3A and 3B  to the connection state in  FIGS. 7A and 7B  or vice versa. The connection configuration in  FIGS. 7A and 7B  is merely an example. The cable  14  may be connected to the side facing in the +Y direction. Thus, with the provision of the three or more slots to one of which the cable  13  or the cable  14  is detachably attached, the degree of freedom for placing the cable  13  and the cable  14  is increased. Further, at least one slot  18  is provided on the side different from the side on which the other slots  16 ,  17  are provided, as illustrated in  FIGS. 7A and 7B . Accordingly, the degree of freedom for placing the cable  13  and the cable  14  is further increased. The slot  16 ,  17 ,  18  to which none of the cable  13  and the cable  14  is connected may be used for another application such as connection of a USB memory. 
     According to the ultrasonic probe  10  described above; the image capturing unit  12  is configured to capture an image of a nearby object, and connected to the probe head  11  through the cable  13  (first cable). Thus, the image capturing unit  12  can image the probe head  11  from a distant position. In other words, the user can move the image capturing unit  12  while holding it so that an abutment state of the probe head  11  can be properly imaged. 
     The image capturing unit  12  and the probe head  11  are integrated with each other through the cable  13  (first cable). Thus, the user can easily carry the ultrasonic probe  10  and the configuration of the housing can be also made compact. That is, even at a place with a large physical limitation such as an emergency ward, it is possible to perform ultrasonic measurement through the patient monitor  20  while grasping an abutment state of the probe head  11  in a simple configuration. 
     The image capturing unit  12  may function as a remote controller of the patient monitor  20  or the probe head  11 . When the image capturing unit  12  functions as the remote controller, the user can change the setting of the patient monitor  20  or the probe head  11  on hand, while viewing the image (the ultrasonic image  21  or the photographic image  22 ) displayed on the patient monitor  20 . 
     In the configuration illustrated in  FIG. 2 , the connector  15  is provided to be connected to the patient monitor  20 . The connector  15  has a universal shape which can be inserted into a vacant slot provided in a general patient monitor  20 . Therefore, as long as ultrasonic wave displaying software is installed into the patient monitor  20 , the patient monitor  20  can realize an ultrasonic measurement system which can easily acquire an image equivalent to a body mark only when the ultrasonic probe  10  is connected to the patient monitor  20 . A range from the connector  15  to the probe head  11  is connected by wire. Accordingly, the ultrasonic probe  10  is easily carried and high in universalness. Therefore, for example, assume that the ultrasonic wave displaying software has been installed into each of patient monitors  20  in each ward in advance. In this case, an ultrasonic image and a photographic image (equivalent to a body mark) can be checked through any of the patient monitors  20  only by detachably attaching which the ultrasonic probe  10  which is easy to carry, regardless of whether the patient monitor  20  is old or new. 
     On the other hand, the cable  14  through which the image capturing unit  12  and the patient monitor  20  can be connected to each other is absent from the configuration illustrated in  FIG. 6 . Thus, the size of the housing of the ultrasonic probe  10  can be further reduced. Thus, the ultrasonic probe  10  can have a configuration that is easier to carry, and that is further prevented from being an obstacle even at an emergency scene etc. 
     Description has been made on the assumption that the ultrasonic probe  10  is connected to the patient monitor  20  in the aforementioned configuration. However, the connection of the ultrasonic probe  10  is not always limited thereto. For example, the ultrasonic probe  10  may be configured to be connected to a tablet type personal computer in which ultrasonic image displaying software is installed. That is, the ultrasonic probe  10  may be electrically connected to a display device (the patient monitor  20 , the tablet type personal computer, etc.) that can display an ultrasonic image. Even when the ultrasonic probe  10  is connected to the tablet type personal computer, it is possible to properly grasp an abutment state of the probe head  11  in a simple configuration as long as the ultrasonic probe  10  has the aforementioned configuration. 
     Next, a configuration of an ultrasonic probe  10  according to another embodiment of the presently disclosed subject matter will be described. In the following description, elements denoted by the same reference signs and names as those of the foregoing embodiment are similar to or the same as those of the foregoing embodiment unless otherwise described. 
       FIG. 8  is a view illustrating how the ultrasonic probe  10  may be used according to the present embodiment. A probe head  11  is connected to a patient monitor  20  through a cable  13 . An image capturing unit  12  is connected to the patient monitor  20  through a cable  14 . The image capturing unit  12  has an optical lens  121  that captures a photographic image of a nearby object in a similar manner to or the same manner as that of the foregoing embodiment. The image capturing unit  12  transmits the captured photographic image (an image signal or digital data showing the image) to the patient monitor  20 . The image capturing unit  12  functions as a remote controller that transmits a control signal to the patient monitor  20  and the probe head  11 . The image capturing unit  12  creates the control signal in accordance with operation on input interfaces (input buttons  123  etc.). The image capturing unit  12  may transmit the control signal to the probe head  11  through the cable  13  and the cable  14 , or may transmit the control signal to the probe head  11  using a wireless communication function (e.g., a short range wire communication function). 
     Data communication between the probe head  11  and the patient monitor  20  may be also achieved by wireless. Data communication between the image capturing unit  12  and the patient monitor  20  may be also achieved by wireless. That is, as long as the ultrasonic probe  10  may have a configuration including the probe head  11  and the image capturing unit  12 , housings of the probe head  11  and the image capturing unit  12  may be connected to each other by a cable or not by a cable. That is, the image capturing unit  12  may be connected to the probe head  11  by wire or by wireless. 
     The probe head  11  transmits an ultrasonic beam toward a body surface of a subject and receives a reflected wave from the body surface. A signal of the reflected wave acquired by the probe head  11  is supplied to the patient monitor  20  through the cable  13 . Ultrasonic image data may be alternatively supplied to the patient monitor  20  after the signal of the reflected wave has been converted into the ultrasonic image data. That is, the probe head  11  may supply the image information based on the reflected wave to the patient monitor  20 . 
     The photographic image acquired by the image capturing unit  12  and the image information acquired by the probe head  11  are supplied to the patient monitor  20 . In other words, the ultrasonic probe  10  supplies the photographic image acquired by the image capturing unit  12  and the image information acquired by the probe head  11  to the patient monitor  20 . The patient monitor  20  displays an ultrasonic image  21  and a photographic image  22  on a display in a similar manner to or the same manner as that according to the foregoing embodiment. While referring to the ultrasonic image  21  or the photographic image  22  displayed on the patient monitor  20 , a nurse N adjusts a pointing direction (imaging direction) of the image capturing unit  12  or operates the input interfaces (the buttons etc. provided on the image capturing unit  12 ) to input various setting changes (setting of the probe head  11  or setting of the patient monitor  20 ). A control signal in accordance with operation on the input interfaces is input to the probe head  11  or the patient monitor  20 . 
     According to the ultrasonic probe  10  described above, when the ultrasonic image is referred to, measured values or measured waveforms of vital signs are often desired to be referred to together. In addition, it is preferable that a user (medical worker) may perform grasping of an ultrasonic image of the subject, grasping of an abutment state of the probe head  11 , and change of the setting of the probe head  11 , etc. without changing one&#39;s gaze frequently. 
     The image capturing unit  12  is configured to capture a photographic image of a nearby object and to transmit a control signal to the probe head  11 . That is, the image capturing unit  12  has a configuration in which both the remote controller of the probe head  11  and the imaging can be integrally performed. The image capturing unit  12  supplies the photographic image to the patient monitor  20 . The probe head  11  supplies image information about an ultrasonic wave to the patient monitor  20 . Therefore, the user can properly record the image equivalent to a body mark, and can control the probe head  11  while viewing the photographic image or the ultrasonic image displayed on the patient monitor  20 . That is, the user can comfortably perform imaging of the body mark, the setting change (control) of the probe head  11 , and checking of the ultrasonic image. 
     The image capturing unit  12  may be configured to transmit a control signal to the probe head  11  via the patient monitor  20 . The image capturing unit  12  transmits a control signal according to operation on the input interfaces (the input buttons  123  etc.) on the image capturing unit  12  to the patient monitor  20  by wired communication or by wireless communication. The patient monitor  20  detects whether the control signal is addressed to the patient monitor  20  or addressed to the probe head  11 . When the control signal indicates setting change of the probe head  11 , the patient monitor  20  transmits the control signal to the probe head  11  by wired communication or by wireless communication. 
     Even with the configuration, the image capturing unit  12  is configured to be able to capture a photographic image of a nearby object, and can transmit the control signal to the probe head  11  and properly record the image equivalent to a body mark. The image capturing unit  12  can also control the probe head  11  in accordance with the photographic image. 
     While the presently disclosed subject matter has been described with reference to certain embodiments thereof, the scope of the presently disclosed subject matter is not limited to the embodiments described above, and it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the scope as defined by the appended claims. 
     The present application claims priority to Japanese Patent Application No. 2017-221591 filed on Nov. 17, 2017, the entire content of which is incorporated herein by reference.