This application claims priority from Korean Patent Application No. 10-2014-0044685, filed on Apr. 15, 2014 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
1. Field
Exemplary embodiments relate to an ultrasonic imaging apparatus, and more particularly to an ultrasonic imaging apparatus capable of efficiently dissipating heat from an ultrasonic probe during diagnosis.
2. Description of the Related Art
Medical ultrasonic imaging apparatuses are generally classified into non-invasive type ultrasonic imaging apparatuses and invasive type ultrasonic imaging apparatuses. One of the representative invasive type ultrasonic imaging apparatuses is a transesophageal echocardiography (TEE) imaging apparatus.
Transesophageal echocardiography is an established technique in the area of cardiac imaging, and involves insertion of a probe into a subject's esophagus. The probe, which is affixed to a distal end portion of a long tube, is positioned near a heart through a subject's esophagus, irradiates ultrasonic waves toward a heart and surrounding tissues (i.e., an object to be diagnosed), and obtains images of heart chambers, valves and surrounding tissues by receiving an ultrasonic echo signal which is reflected from the object.
The tube used in the transesophageal echocardiography may have proper rigidity and flexibility to be inserted into a subject (e.g., human body) via a subject's esophagus. Further, there is provided a bending part which is bendable between the tube and the probe so that the probe may pass through a curved esophagus and may be disposed at the optimum position for heart diagnosis.
It is an aspect of one or more exemplary embodiments to provide an ultrasonic imaging apparatus capable of effectively dissipating heat from a probe during diagnosis.
Additional aspects of the exemplary embodiments will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the exemplary embodiments.
In accordance with one aspect of one or more exemplary embodiments, an ultrasonic imaging apparatus comprises an ultrasonic probe arranged at a distal end portion of the ultrasonic imaging apparatus and a bending part connected to the ultrasonic probe and configured to be bendable. Heat generated from the ultrasonic probe is dissipated toward the bending part.
As is apparent from the above description, the thermal stability of the ultrasonic probe may be enhanced by efficiently dissipating heat generated from the ultrasonic probe by using a capacitive micromachined ultrasonic transducer (cMUT).
Further, because it is not necessary to form a backing layer for improvement of residual vibration characteristics, the structure and manufacturing processes may be simplified.
These and/or other aspects of the exemplary embodiments will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings of which:
Now, exemplary embodiments will be described in detail with reference to the annexed drawings. In the drawings, the same or similar elements are denoted by the same reference numerals even though they are depicted in different drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the exemplary embodiments rather unclear. It will be understood that the terms first, second, etc. may be used herein to distinguish one component from another component and these components should not be limited by these terms.
Hereinafter, the exemplary embodiments will be described based on a transesophageal echocardiography (TEE) apparatus, however, the exemplary embodiments are not limited to the transesophageal echocardiography (TEE) apparatus, but may be applied to all kinds of ultrasonic imaging apparatuses.
Referring to
The ultrasonic probe 110 is configured to irradiate ultrasonic waves toward an object and to acquire an image of the interior of the object by receiving an ultrasonic echo signal which is reflected from the object. As shown in
The ultrasonic transducer 111 functions to convert an electrical signal supplied from the outside into a mechanical vibration energy in order to generate ultrasonic waves, and also functions to convert a vibration transmitted from the outside into an electrical signal.
In this exemplary embodiment, as the ultrasonic transducer 111, a capacitive micromachined ultrasonic transducer (cMUT) may be employed, however, the exemplary embodiments are not limited thereto. As the ultrasonic transducer 111, a piezo-electronic transducer (PZT) may be employed. Hereinafter, for convenience of explanation, the exemplary embodiments will be described with reference to a case in which a cMUT is used as the ultrasonic transducer 111.
The cMUT is a relatively new concept in the field of ultrasonic transducers which transmit and receive ultrasonic waves by using vibrations of hundreds or thousands of microprocessed thin films. Such a cMUT may be manufactured based on micro electro mechanical system (MEMS) technology. A capacitor is formed by forming a lower electrode and an insulating layer on a semiconductor substrate commonly used in semiconductor manufacturing processes, forming an air gap on the insulating layer including the lower electrode, forming a thin film with a thickness of several to thousands of angstroms on the air gap, and forming an upper electrode on the thin film.
When an alternating current is applied to the capacitor, ultrasonic waves are generated by vibration of the thin film. Conversely, when the thin film is caused to vibrate by external ultrasonic waves, the capacitance of the capacitor varies. By detecting such capacitance variation, ultrasonic waves are detected.
Because each of the thin films of the cMUT has a diameter of dozens of micrometers (μm), an array of tens of thousands of thin films has a size of approximately several millimeters. In addition, because tens of thousands of thin films may be accurately arranged at desired positions via a single semiconductor manufacturing process, and the cMUT is electrically connected to the integrated circuit by chip bonding, such as flip-chip bonding, in order to apply electrical signals to the cMUT, process complexity due to wiring may be overcome.
In addition, because the cMUT has poor vibration transmissibility due to the air gap, it is not necessary to form a backing layer for improvement of residual vibration characteristics on a rear surface of the printed circuit board 113, which will be described below. Accordingly, the structure and manufacturing processes may be simplified.
Further, because the cMUT has broadband characteristics, the cMUT may obtain an image of higher resolution than the resolution of a corresponding image obtained by a piezo-electronic transducer. Because the cMUT is adequate for manufacturing a transducer having a two-dimensional array structure, development of a multichannel transducer may be facilitated, and thus a three-dimensional image may be realized in the field of the ultrasonic imaging apparatuses.
The ultrasonic transducer 111, as which the cMUT is used, may have a two-dimensional array structure, as shown in
The tile 111A includes elements 111B which are arranged in a two-dimensional array. In each element 111B, a plurality of thin films 111C, which vibrate in response to an electrical signal applied thereto, may be arranged in a two-dimensional array.
For example, as shown in
As such, the cMUT is adequate for manufacturing the transducer having a two-dimensional array structure, which facilitates development of a multichannel transducer. However, while an amount of heat which is generated in electrical circuits which are designed for driving the ultrasonic probe 110 which includes transducers having a relatively small number of channels is approximately equal to one watt (i.e., 1 W), which may be naturally dissipated through a probe case, an amount of heat which is generated in electrical circuits which are designed for driving the ultrasonic probe 110 which includes multichannel transducers is approximately equal to 7 W. Thus, there is a need to develop techniques for dissipating heat generated by the ultrasonic probe 110 and for cooling the ultrasonic probe 110.
Therefore, one or more exemplary embodiments is designed to effectively dissipate heat generated by the ultrasonic probe 110.
The integrated circuit 112 is configured to drive the ultrasonic transducer 111 by applying an electrical signal to the ultrasonic transducer 111 in order to generate an ultrasonic signal and to detect an electrical signal output from the ultrasonic transducer 111 by the ultrasonic signal transmitted to the ultrasonic transducer 111 from the outside. As shown in
The ultrasonic transducer 111 may be installed on the front surface of the integrated circuit 111, for example, by flip-chip bonding as described above, however, the exemplary embodiments are not limited thereto.
Although not illustrated, the integrated circuit 112 may include an analog beamformer, an analog-to-digital converter (ADC) and a digital beamformer, however, the exemplary embodiments are not limited thereto.
The analog beamformer functions to output electrical signals to the ultrasonic transducer 111, thereby enabling the thin films 111C constituting the ultrasonic transducer 111 to respectively generate ultrasonic signals. In this aspect, the electrical signals output from the analog beamformer correspond to the respective thin films 111C, and thus the same number of the electrical signals as the number of the thin films may be output.
In order to cause the ultrasonic signals generated by the ultrasonic transducer 111 to overlap at a focusing point, the ultrasonic signals should arrive at the focusing point at the same time. However, there may be a difference in distances between the respective thin films 111C of the ultrasonic transducer 111 and the focusing point, and such a difference in distance may cause a predetermined gap of time in which the ultrasonic signals arrive at the focusing point.
Accordingly, in order to ensure that ultrasonic signals generated by the ultrasonic transducers 111 arrive at the focusing point at approximately the same time, the thin film positioned relatively far from the focusing point generates an ultrasonic signal earlier, and the thin film positioned relatively close to the focusing point generates an ultrasonic signal later. To this end, the analog beamformer acts to output electrical signals to be applied to the respective thin films 111C at different points of time. As a result, the respective thin films 111C constituting the ultrasonic transducer 111 generate ultrasonic signals at different points of time.
When the ultrasonic signals arrive at the focusing point, the ultrasonic signals may be reflected by the focusing point and/or by the surrounding body tissues. When the reflected return signals arrive at the ultrasonic transducer 111, the ultrasonic transducer 111 converts the return signals into electrical signals, and transmits the converted electrical signals to the analog beamformer. In this aspect, the same number of the electrical signals as the number of the thin films 111C constituting the ultrasonic transducer 111 may be generated.
When receiving the electrical signals converted by the ultrasonic transducer 111, the analog beamformer adjusts phases with respect to the respective electrical signals in order to overlap the electrical signals to a single signal. The reason for adjusting the phases by the analog beamformer is that the reflected signals arrive at the respective thin films 111C of the ultrasonic transducer 111 at different points of time. Such a single signal generated as a result of the overlapping is converted into a digital signal through the ADC.
The digital beamformer synthesizes the digital signals converted through the ADC according to the precalculated time delay value for digital beamforming in order to form a receiving beam.
By virtue of the analog beamformer, there is no need for a plurality of sampling devices which respectively correspond to the thin films included in the ultrasonic transducer 111, and thus, an increase in complexity of hardware may be avoided. Further, since the analog beamformer causes the electrical signals converted by the ultrasonic transducer 111 to be focused to a subgroup and to be converted into a digital signal, the number of channels may be reduced, and the diameter of the insertion tube 130 may be decreased.
Application specific integrated circuits (ASIC) may be used as the integrated circuit 112, however, the exemplary embodiments are not limited thereto.
As shown in
Because the printed circuit board 113 is made of a material having a relatively low thermal conductivity, as shown in
As shown in
Since the rear surface of the integrated circuit 112 and the heat spreader 114 which will be described below may thermally contact each other through the thermal grease, the phase change material and/or the vias, heat generated by the integrated circuit 112 may be more rapidly absorbed in the heat spreader 114.
The heat spreader 114 is configured to absorb heat generated by the integrated circuit 112 of the ultrasonic probe 110, and may be arranged on the rear surface of the printed circuit board 113.
The heat spreader 114 may be made of a metal, such as, for example, aluminum, however, the exemplary embodiments are not limited thereto. Any material having a relatively high thermal conductivity may be used for the heat spreader 114.
The heat spreader 114 may include a protruding part which extends toward a bending part 120 (refer to
For convenience of explanation, the protruding part formed in a plate shape is denoted by ‘A’, and the protruding part formed in a pipe shape is denoted by ‘B’. The protruding part A or B may be thermally connected to a heat transferer which will be described below.
The ultrasonic probe 110 according to an exemplary embodiment may further include a housing 115 in which the ultrasonic transducer 111, the integrated circuit 112, the printed circuit board 113 and the heat spreader 114 are accommodated. The housing 115 may be made of any one or more of plastic, fiberglass, epoxy, or the like, however, the exemplary embodiments are not limited thereto.
The housing 115 may include a window configured to irradiate ultrasonic signals to the outside and to receive the external ultrasonic signals therethrough. As shown in
The ultrasonic imaging apparatus 100 according to an exemplary embodiment may further include a heat transferer configured to transfer heat absorbed in the heat spreader 114 from the integrated circuit 112 toward the bending part 120.
As the heat transferer, a refrigerant circulation device or graphite may be employed, however, the exemplary embodiments are not limited thereto.
Referring to
The bending part 120 has a multi-joint mechanism which is bendable. As shown in
The bending part 120 may include a plurality of segments and manipulation wires which are configured to connect the respective segments to each other. Such a bending part 120 composed of the segments is formed in a hollow cylindrical shape, in which a signal transmission cable which is configured to transmit a signal from a back-end system to the ultrasonic probe 110 and vice versa is accommodated.
The bending part 120 may be made of a metal, however, the exemplary embodiments are not limited thereto. Any material having a relatively high thermal conductivity and certain intensity may be used for the bending part 120.
An outer wall of the bending part 120 may be coated with a material having a relatively high thermal conductivity. Thereby, heat transferred to the inner wall of the bending part 120 via the graphite 210 may be easily dissipated to the outside via the outer wall of the bending part 120. Accordingly, heat generated by the integrated circuit 112 is dissipated to the outside via the heat spreader 114, the graphite 210 and the bending part 120.
In this exemplary embodiment, cooling water is used as the refrigerant, however, the refrigerant is not limited to cooling water. The refrigerant circulation device may include a refrigerant circulation tube 220 configured to circulate the refrigerant therethrough and a water pump 221 configured to supply the refrigerant to the heat spreader 114 and to receive the refrigerant passing through the heat spreader 114, however the refrigerant circulation device is not limited to the above structure.
Referring to
The refrigerant circulation tube 220 may have one end connected to the protruding part B of the heat spreader 114 and an opposite end connected to the water pump 221. Accordingly, as shown in
Because the refrigerant flowing back into the water pump 221 after circulating within the interior of the heat spreader 114 carries the heat absorbed in the heat spreader 114 from the integrated circuit 112 to the water pump 221, the temperature of the refrigerant in the water pump 221 increases. Accordingly, as shown in
The heat sink 223 is configured to disperse the heat carried to the water pump 221 in order to dissipate the heat to the outside. Although not illustrated in
As described above, heat absorbed in the heat spreader 114 is carried to the water pump 221 by circulating the refrigerant through an internal passage 114c of the heat spreader 114 which has absorbed heat from the integrated circuit 112, and then the heat carried to the water pump 221 is dissipated to the outside by using the heat sink 223.
The refrigerant circulation tube 220 may be directly connected to the protruding part B of the heat spreader 114 as described above. Alternatively, as shown in
This is because it may be difficult to directly connect the refrigerant circulation tube 220 to the relatively small-sized protruding part B of the heat spreader 114. In this case, a passage P through which the refrigerant circulates may be formed inside the inner casing 114A.
The heat spreader 114 according to an exemplary embodiment, as shown in
The insertion tube 130, as shown in
The manipulation device 140 functions to enable a user to manipulate the operation of the ultrasonic probe 110. For example, as shown in
The movement of the ultrasonic probe 110 from side to side and up and down by the manipulation device 140 will presently be described.
Although not illustrated in
When a user rotates the first knob 141 in one direction or in the reverse direction, the corresponding manipulation wire is manipulated (for example, is pulled), so that the bending part 120 is bent left or right. As a result, the ultrasonic probe 110, which is affixed to a distal end portion of the bending part 120, is also moved left or right. When a user rotates the second knob 142 in one direction or in the reverse direction, the corresponding manipulation wire is manipulated, so that the bending part 120 is bent up or down. As a result, the ultrasonic probe 110, which is affixed to the distal end portion of the bending part 120, is also moved up or down.
Although the mechanism in which the ultrasonic probe 110 is operated by manipulating the manipulation device 140 has been described, this is merely illustrative. The operation mechanism of the ultrasonic probe 110 is not limited to the above-described mechanism.
Although not illustrated in
The ultrasonic imaging apparatus 100 according to an exemplary embodiment may further include a connector 160 connected to the back-end system (not shown) and a cable 150 which is configured to connect the connector 160 and the manipulation device 140 to each other.
Although a few exemplary embodiments have been shown and described, it will be appreciated by those of ordinary skill in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the present inventive concept, the scope of which is defined in the claims and their equivalents.
Number | Date | Country | Kind |
---|---|---|---|
10-2014-0044685 | Apr 2014 | KR | national |