Patent Publication Number: US-2022233180-A1

Title: A mechanical wave inducing device being connectable to a needle

Description:
FIELD OF TECHNOLOGY 
     The invention relates to a mechanical wave inducing device being connected to a needle. The needles are used for medical purpose, e.g. biopsy in order to take samples from a patient&#39;s body. Known needle biopsy techniques are for example Fine-Needle Aspiration (FNA) and Core Needle Biopsy (CNB). The mechanical wave inducing device can, for example, comprise an ultrasonic device, an RF source, photo-acoustic, electric spark gap or an electric motor. 
     PRIOR ART 
     Needles are broadly employed in medicine, e.g. in drug delivery, surgical procedures and to sample tissue (needle biopsy) or blood. In needle biopsy, to simplify, the tip of the needle is penetrated into the target tissue or the vein of interest, and a syringe, which is attached to the needle is used to provide a low pressure in the needle in order to suck a part of the tissue or fluid through the needle for further examination. There are also other techniques to provide the low pressure in the needle such as vacutainers. 
     The problem of the current biopsy solutions is that amount of the tissue or fluid, which is obtained from the needle, is relatively small. There are solutions wherein this problem has been solved by transmitting energy to the tip of the needle in order to obtain movement at the tip of the needle. In this way the needle tip can be made to move inside the target tissue very rapidly, which extracts or loosens parts of the target tissue or fluid more efficiently than without the transmission of the energy to the tip. 
     Therefore, more sample material can be obtained from the tissue or fluid. An alternative solution is to increase needle size, but in order to avoid risk for trauma for the patient this is not so desired. Ultrasound can be used for transmitting such energy to the needle tip. WO 2018000102 shows a known embodiment that utilizes ultrasound transmission. Although the solution of this WO publication is appropriate, it is quite large and has connection cables and tubes limiting portability or usability. 
     SHORT DESCRIPTION 
     The aim of the invention is to alleviate the problems of the prior art by allowing efficient conversion of electric energy to mechanical energy in a small and, if necessary, in portable size with handheld devices. The frequency of the mechanical waves can, for example, be at the ultrasound range. The aim is achieved by a device described in an independent claim. Dependent claims disclose different embodiments of the invention. 
     The inventive device is a mechanical wave inducing device being connectable to a needle. The device has a displacement source  5  and an arrangement for a driving signal. The device has at least two wing parts  9 ,  9 A,  9 B,  9 C,  10 ,  10 A,  10 B,  10 C, which are in connection with the displacement source  5 . Each wing part  9 ,  9 A,  9 B,  9 C,  10 ,  10 A,  10 B,  10 C is arranged to be attachable with the needle  1 , and each wing part comprises a connection portion  91 ,  92 ,  93 ,  94 ,  95 ,  96 ,  97 ,  98 ,  99 , through which the wing part  9 ,  9 A,  9 B,  9 C,  10 ,  10 A,  10 B,  10 C is in connection with the displacement source  5 . The connection portion is a wing part specific or common to the wing parts. 
     Each wing part with the connection portion is a converter in order to convert longitudinal mechanical wave movement created by the displacement source into transversal mechanical wave movement for the needle  1 , where the transversal mechanical wave is defined as a mechanical wave having particle displacement different from the direction of the wave propagation. It is also possible that at least one of said wing parts  9 ,  9 A,  9 B,  9 C,  10 ,  10 A,  10 B,  10 C has a section of a tapered form. 
     The displacement source can produce a longitudinal mechanical movement in the direction of its longitudinal axis in a relatively small space. At least two wings attachable with the needle makes it possible to transmit the mechanical wave efficiently to the needle including control of the direction of the energy propagation within the needle. However, in order to achieve a desired action for biopsy the device should move the needle at an intended direction with respect to the longitudinal axes of the needle, e.g. transversally. In this case, the wing parts convert the longitudinal movement in mechanical displacement source into the transversal movement in the needle with respect to the needle centre axis. The wing parts occupy also relatively small space. The geometries of the wing parts are such that the conversion from the longitudinal movement to the transversal movement makes it possible for efficient transmission of mechanical energy taken into account mechanical wavelengths. 
     Further, when matching the transversal mechanical waves to the distal part of the needle  1  with at least one wing part, even a higher transmission efficiency rate can be achieved allowing smaller power consumption and therefore, the size of the displacement source can be then miniaturized. The intensity of mechanical waves produced by the mechanical wave displacement source can depend on the volume of the displacement source, for example if the source is a piezoelectric transducer. Therefore, good efficiency of the system in converting electricity to needle tip motion allows to use a smaller displacement source and lower power consumption is practical especially if the system is batterized. 
    
    
     
       LIST OF FIGURES 
       In the following, the invention is described in more detail by reference to the enclosed drawings, where 
         FIG. 1  illustrates an example of parts of the inventive device, 
         FIG. 2  illustrates an example of the inventive device, 
         FIG. 3  illustrates an example of the wing part of the inventive device, 
         FIG. 4  illustrates another example of the inventive device, 
         FIG. 5  illustrates yet another example of the inventive device 
         FIG. 6  illustrates another example of the wing part of the inventive device.  FIG. 7  illustrates further another example of the wing part of the inventive device, 
         FIG. 8  illustrates further another example of the inventive device, 
         FIG. 9  illustrates an embodiment of a manufacturing component for yet another example of the wing part, 
         FIG. 10  illustrates another embodiment of a manufacturing component for yet another example of the wing part, 
         FIG. 11  illustrates further another example of the inventive device, 
         FIG. 12  illustrates further another example of the inventive device. 
         FIG. 13  illustrates the wing parts of  FIG. 12 . 
         FIG. 14  illustrates an example of the wing parts for the embodiment of  FIG. 12 , 
         FIG. 15  illustrates another example of the wing parts for the embodiment of  FIG. 12 , and 
         FIG. 16  illustrates another embodiment for the displacement source, 
         FIG. 17  illustrates further another example of the inventive device, and 
         FIG. 18  illustrates an example of the wing parts for the embodiment of  FIG. 17 . 
     
    
    
     DESCRIPTION OF THE INVENTION 
       FIG. 1 . illustrates an example of parts of the inventive device.  FIG. 2  illustrates an embodiment of the invention having the parts shown in  FIG. 1 . The mechanical wave inducing device according to the invention is connectable to a needle  1 . The connection possibilities are described further below. The needle has tip  4  at a distal end of the needle for e.g. puncturing into a target tissue or vein or to achieve another medical function. The proximal end of the needle comprises a connector  2  in order to connect the needle for a low pressure source  3 , e.g. a syringe or a vacutainer. Other low pressure sources can also be used. 
     The device has a displacement source  5  and an arrangement for a driving signal. In the example of  FIG. 2  the driving signal arrangement comprises a driving signal connection part  6  in order to connect the displacement source to a signal source. The driving signal connection part  6  comprises an input connector  7  and connecting lines  8  between the input connector  7  and the displacement source. The connecting lines  8  can be wires or rigid lines for example. The input connector  7  can be connected with a cable  13  in order to the transmit the driving signal from a driving signal generator (not shown) to the displacement source  5  via the connection part  6 . 
     The driving signal generators as such are known, and they are used to provide a driving signal that has a desired waveform (e.g. shape, pulse/burst/continuous, envelope, pulse repetition rate) and power. A suitable waveform and power depend on the displacement source used, the other parts (shape and material parameters such as shape, structure, density and mechanical properties) of the inventive device, the structure of the needle  1  and the target tissue. Different tissues and tissue pathologies have different mechanical, structural and compositional properties and may require different needles and different waveforms to be used. So, several parts of the invention and the form and power of the driving signal affect how efficiently the mechanical wave is transmitted to the needle tip in order to move the tip. 
     The device has two wing parts  9 ,  10 , which can be made of same or different pieces and that are connected to the displacement source  5 .  FIGS. 1 and 2  show embodiments having two separate wing parts, but it is possible that the wing parts belong to the same piece. So when referring to the embodiment of  FIG. 2  the wing parts  9 ,  10  can be manufactured such that they can be parts of one piece. 
     Each wing part  9 ,  10  is arranged to be attachable with the needlel. The examples of  FIGS. 1 and 2  comprise connection points  11 ,  12  to be attached with the needle  1 . 
     Further, each wing part comprises a connection portion  91 ,  92  (See  FIG. 3 .), through which the wing part  9 ,  10 , is in connection with the displacement source  5 . The connection portion can be wing part specific or common to the wing parts. The common connection portion is convenient when the wing parts are manufactured to be parts of one piece. 
     The wing parts with the connection portion/s are also converters in order to convert longitudinal mechanical wave movement created by the displacement source  5  into transversal mechanical wave movement of the needle  1 . Further, as can be seen on the figures, at least one of the wing parts has a section of a tapered form. 
     As said above, the displacement source produces a longitudinal mechanical movement in the direction of its longitudinal axis in a relatively small space. In order to have a compact structure, which is easy and convenient to use by a user, the displacement source can be located in parallel with the needle, so the longitudinal axes of the needle and the displacement source can be parallel as can be seen in the figures. On the other hand the displacement source can also be located transversally with respect to the needle as shown in the example of  FIG. 12 . 
     In inventive embodiments having connection point, like in  FIGS. 1 and 2 , at least one connection point can be designed to match the transversal mechanical waves to the needle  1 . In this way the power can be transmitted relatively efficiently to the needle with minimized reflection of the wave back towards the displacement source 
     One wing part or the both wing parts  9 ,  10  can be used for transmitting the mechanical waves to the needle  1 . Therefore the mechanical movement created by the displacement source can be transmitted efficiently to the needle. Also one connection point or the both connection points  11 ,  12  can be designed to match the mechanical waves to the needle. However, it is also possible that one of the connections points is designed to mismatch mechanical waves to the needle. The mismatching connection point  12  is situated at the side of the proximal end of the needle  1 , and it has been discovered that it limits (at least mostly) the mechanical waves in the needle to propagate towards the proximal end of the needle. The mismatching connection point tends also to reflect waves coming from the direction of  11  towards  12 , towards the tip of the needle  4 . Instead of using the connection point  11 ,  12  (a spot like connection), a long connection area along the needle (a stripe like connection) can be used, as illustrated in the example of  FIG. 12 . The connection area can also be designed to match or mismatch the mechanical waves. 
     A mechanical wave in a structure can be achieved, for example, using an ultrasound device, wherein the propagating waves transmitting energy in the structure move in the ultrasound range from 20 kHz up to several gigahertz. An ultrasound device can be, for example, a piezo electric device like Langevin transducer, an RF source, electric spark gap, a photoacoustic device or a small electric motor. It should be noted that other techniques and frequency ranges may also be used than the ultrasound technique. For example devices that create frequencies greater than 0.1 Hz can be used, like air pressure devices or small electric motors. In order for the mechanical wave to propagate properly through interfaces of components, mechanical wave impedances of the components, e.g. the needle and wing part, should be similar or at least close to each other. It can be said that the mechanical wave impedance is the ratio of stress applied to component to velocity of the wave in the component. If the impedances of the components differ significantly reflections of the mechanical waves may occur and the waves do not propagate properly between the components. Therefore, materials of the component in the view of the mechanical wave impedances would be practical to be as close as possible in order to provide a good wave propagation through the interfaces, if necessary. An alternative solution is to use an intermediate layer between the components for matching the impedances of the components as close to each other as possible. 
     A mechanical wave inducing device comprises a body part  14  that can comprise the displacement source  5  and the driving signal connection part  6  as shown in  FIG. 2 . The body part provides an installation frame for the parts of the device and also a grip for a user of the device. So, the device can be hand-held. 
     The connection points  11 ,  12  (or the connection areas) can be fixed, in which case the needle and device forms one product. Therefore, the connection/s  16 ,  17  between the wing part/s  9 ,  10  and the displacement source  5  can also be fixed. However, it is also possible that the connections  16 ,  17  between the wing part/s  9 ,  10  and the displacement source  5  can also be detachable. Further, alternative embodiments are that the connection points  11 ,  12  are detachable, in which case the needle can be disposable. 
       FIGS. 1 and 2  shows an example of a mechanical wave inducing device wherein one of the wing parts  9  comprises a sub part  18  of the wing  9  and a bar  19 , the bar being in a transversal direction with respect to a longitudinal axis  5 A of the displacement source  5 .  FIG. 3  shows the wing part  9  of this example, and also illustrates the other wing part  10 . The bar  19  comprises the connection portion  92 , which is in connection with the displacement source  5 . the sub part  18  of the wing part  9  is in a transversal direction with respect to the bar  19 , and has said tapered form with a wide end  18 A and a narrow end  18 B. The narrow end has the connection point  11  (or connection area) to match the mechanical waves to the needle  1 , and the wide end  18 A is connected to the bar  19 . 
     If the wing parts  9 ,  10  belong to one piece, the bar  19  and the connection portion  92  are common with the other wing part  10  and the wing part  9  having said sub part  18 . If the wing parts  9 ,  10  are different pieces as illustrated in  FIG. 3 , the other wing part  10  is a second bar situated in parallel with the bar  19 , and having the other connection point  12  for the needle  1 , and also the connection portion  91 . A tapered shape of the wing part  9 , more precisely the sub part  18  of the wing  9 , increases the energy density of the mechanical wave towards the connection point  11 . 
     As said, at least one of the connection points  11 ,  12 , or connection areas matches with respect to the mechanical waves, so the connection point matches the mechanical wave impedances of the needle  1  and the wing part. In the examples of  FIG. 1-3  at least the connection point  11  or connection area, which is closer to needle tip is designed to match the mechanical waves to the needle. The other connection point  12  or connection area can be designed to mismatch the mechanical waves, which limits the propagation of the mechanical waves towards the proximal end of the needle  1 , i.e. towards the low pressure source  3 . Preventing propagation of the mechanical wave preserves the connection hub for unnecessary exposure of the said waves, e.g. protecting the operator from obtaining mechanical wave exposure, protecting the sample obtained or protecting the needle hub from unnecessary stresses or breakage. 
     The connection point  11   12 , or connection area can be made in many ways, like using crimps, solder joints and adhesive (e.g. glue). The figures show schematically the connections points, so in practice they differ from the figures. 
       FIG. 3  shows also a hole  30  that is used to connect the wing part/s with the displacement source  5 . In addition, the device may comprise at least one additional connection  15  with the needle. The additional connection can be useful for example to manufacture an inventive product. 
     The wing part  9  having a section of a tapered form is located on one side with respect to the displacement source  5  as shown in  FIG. 2 . In addition, it is possible that there is a wing part  103  that is directed to an opposite side with respect to the displacement source  5 . The wing part  103  directed on the opposite side of the displacement source than the wing part having the tapered form tends to increase the efficiency of the mechanical wave energy transmission towards the connection point  11  or connection area. This applies to other embodiments of the invention as well. As can be noted the other wing part  10  may also comprise a wing part  104  directed to the opposite side with respect to the displacement source  5 . 
       FIG. 3A  discloses a further embodiment wherein the other wing part  9  comprises a projection  10 AC on the other side of the other connection point  12  than the displacement source  5 .  FIG. 3A  shows also an embodiment of the projection in dashed lines, if the wing parts  9 ,  10  belong to one piece, more precisely the part  10  and the bar  19 . The projection  10  AC works as a counterweight in relation to the other connection point  12 . The projection can increase a torque effect, which can lead to a better wave transmission. Therefore, the effect at the needle tip can be improved. As can be seen in  FIG. 3A  the wing parts  9 ,  10  can be formed separately or as a common part. Further the length of the projection can vary, depending on the design of an embodiment. 
       FIG. 2  illustrates also the conversion of the longitudinal mechanical wave movement into transversal mechanical movement. The longitudinal mechanical wave  81  created by the displacement source  5  moves the wing parts  9 ,  10 . Since the wing parts have a transversal structure comprising the connection portion  92 ,  91  with respect to the centre axes of the displacement source  5 , they convert the longitudinal mechanical wave movement into the transversal mechanical wave movement  82  with respect to the needle. 
       FIG. 4  shows another embodiment wherein a battery  41 , a control interface  42 , a controller  43 , a signal generator  44  and an amplification unit  45  are situated in the body part  14 . In this way an external signal source, power source and other parts are not needed. There the cable  13  is connecting the displacement source  5  and amplification unit  45 , but the input connector  7  is not needed.  FIGS. 2 and 4  show different embodiments the inventive device could be manufactured. It is worth to note that the examples of  FIGS. 2  an  4  are not only solutions, but the inventive device can be made in other ways as well, for example having no internal power source  41  in the embodiment of  FIG. 4 , but having an external power course that is connectable to the device. 
     A battery  41  can be connected with the controller  43  that distributes power for the other parts in the body part. The battery can also be connected directly (dashed lines in  FIG. 4 ) with all parts in order to distribute power. It is convenient that the battery can be recharged when needed. The control interface can, for example, be a display, touchscreen, button/s, thumbwheel etc. so that a user can control the device. The controller  43  controls the operation of the device, being for example a digital signal processor. The signal generator  44  generates an electric drive signal that is transmitted to the displacement source  5 . The transmission is made via the amplifier  54  that amplifies the driving signal to have a desired power. Connections can be made through circuits and the controller to obtain information from displacement source  5  performance regarding mechanical wave motions within the system to automatically change parameters of the signal generator  44 . Example of such process is measuring optimal resonance frequency of the system or maximizing electric output power from amplifier unit  45 . 
       FIG. 5  shows another embodiment of the inventive mechanical wave inducing device wherein the device has two wing parts  9 A,  10 B, and one of the wing parts  9 A comprises a front bar  20 , the front bar being in a transversal direction with respect to a longitudinal axis  5 A of the displacement source  5 . The front bar  20  comprises a connection portion  93  being connected to a front part  51  of the displacement source  5  and the front bar  20  having one of said connection points  11 . The other wing part  10 A comprises a rear bar  21 , the rear bar being also in a transversal direction with respect to the longitudinal axis  5 A of the displacement source  5 , The rear bar  21  comprises the connection portion  94  and is connected to a rear part  52  of the displacement source  5  and has the other of said connection points  12 . 
       FIGS. 6 and 7  illustrates the front bar  20  and the rear bar  21 . As already said, the bars can be tapered. The tapered shape can be made in many ways, as shown by the dashed lines in  FIG. 7 .  FIGS. 6 and 7  show also connection holes  30 ,  31  for the displacement source. Further,  FIG. 6  illustrates by using the dashed lines that the bar can be fixed with front part of the displacement source (also possible with the rear part). The front and rear bars, i.e. the wing parts may also comprise a further wing  105 ,  106  directed on the opposite side of the displacement source than the wing part having the tapered form as illustrated in  FIGS. 6 and 7 . The bars can also have a rectangular shape as illustrated in  FIG. 3 . They can also vertically widen along the structure towards  12 , if acoustic mismatch is intended to be pronounced. 
       FIG. 8  shows a further example of a mechanical wave inducing device according to the invention. For maximum displacement at the tip of the waveguide (wing part), the rate of tapering can be limited. A long waveguide can thus be folded to make the waveguide fit into a small volume. 
     At least one wing part  9 B has a folded structure, the tapered shape, and also having an extension element  23 , the extension element is approximately in a transversal direction with respect to a longitudinal axis  5 A of the displacement source  5 , and the extension element has one of said connection points  11 . 
       FIG. 11  shows another embodiment of this structure. In the embodiment of  FIG. 11  the other of the wing parts  10 A has a bar form  21  having the connection portion  94  the other connection point  12 . This wing part  10 A can also be rectangular or diverging upwards. 
     In the embodiment of  FIG. 8  the other of the wing parts  10 B has also a folded structure and a tapered shape, and also a second extension element  24 . The second extension element is also in the transversal direction with respect to a longitudinal axis  5 A of the displacement source  5 , and the second extension element has the other connection point  12 . In case of resonant waves, if desired, it is possible that the folded structure or structures  9 B,  10 B can be designed to locate nodes of the mechanical waves induced by the displacement source  5  to peaks  25  and troughs  26  of the folded structure or structures. 
     It is also possible in the embodiments of  FIGS. 8 and 11  that the connection point  11  of the wing part  9 B having said folded structure is designed to match mechanical waves to the needle  1 , and the other connection point  12  of the bar form wing part  21  or the other folded structure  10 B is designed to mismatch mechanical waves to the needle  1 . 
       FIGS. 9 and 10  show the folded wing parts without folding, i.e. as straight prefabricated components, when the tapered form the wing parts can be seen clearly.  FIGS. 9 and 10  illustrates also the common connection portion  95 ,  96 . The tapered shape provides a good wave propagation and promotes also the mechanical wave matching with the needle. There can be many different tapered shapes as illustrated in  FIG. 10 . A flat end of a rectangular form can be used if the mechanical wave mismatching is desired. Alternatively, the structure  10  can be wider at mismatching point  12  than the width near  5 A. When using folded wing parts, i.e. waveguides, the mechanical wave matching with the needle can be achieved conveniently in a compact space. As can be noted in  FIGS. 9 and 10 , the wing part  9 B,  10 B may also comprise a wing  107 ,  108  at the opposite direction than the tapered part with respect to the common connection portion  95 ,  96 . 
     In one embodiment the connection point  11  of the wing part  9 B having said folded structure is designed to match mechanical waves to the needle  1 , and the other connection point  12  of the bar form wing part  21  is designed to mismatch mechanical waves to the needle  1 . As said, the folded structure  9 B,  10 B can be designed to locate nodes of the mechanical waves induced by the displacement source  5  to peaks  25  and troughs  26  of the folded structure. 
       FIG. 12  shows yet another example of the invention how the invention can be provided. In this embodiment the device has two wing parts  9 C,  10 C having the common connection portion  97 . The both wing parts,  100 ,  9 C are in a transversal direction with respect to a longitudinal axis  5 A of the displacement source  5 , and having a common longitudinal axis, the both wing parts being directed to opposite directions on along the common longitudinal axis. The common connection portion  97  connects the wing parts to the displacement source  5 . The displacement source  5  can be situated in the body part  14  although not shown in  FIG. 12 . 
     The both wing parts  10 C,  9 C has a shaft like form, the first wing part  9 C having a tapered form with a wide end and a narrow end. The narrow end having said connection point  11 , and the wide end comprising a part of said connection portion  97 . The second wing part  10 C has the other connection point  12  and another part of said connection portion  97 . 
     The connection point  11  at the narrow end of the tapered form can be arranged to match the mechanical waves to the needle  1 . The connection point  12  at the second wing part  100  can be arranged to mismatch the mechanical waves to the needle  1 . 
       FIG. 12  shows also another embodiment of the invention. In this embodiment the device has also two wing parts  9 C,  10 C having the common connection portion  97 , the both wing parts,  100 ,  9 C being in a transversal direction with respect to a longitudinal axis  5 A of the displacement source  5 , and having a common longitudinal axis. The both wing parts being directed to opposite directions along the common longitudinal axis. 
     The both wing parts  100 ,  9 C has a shaft like form, the first wing part  9 C having a tapered form with a wide end and a narrow end, the wide end comprising a part of said connection portion  97 . Instead of having the connection point, the first wing part  9 C has also one connection area  102 , and the second wing part  100  has the other connection area  101  and also another part of said connection portion  97 . 
     The connection areas  101 ,  102  have a stripe like form. The length of the stripe like connection can be designed to be suitable with other structures of the device like, the needle size and the shape of the wing part. The connection areas  101 ,  102  of the wing parts may also be so long that they are in connection with each other and reach points  11  and  12 . 
       FIG. 13  shows the wing parts  9 C,  10 C of the embodiments of  FIG. 12  and the common connection portion  97  viewing form another angle. The displacement source is illustrated as a dashed line circle. 
       FIG. 14  shows another embodiment and the common connection portion  98  wherein first wing part  9 C and the second wing part  100  form an integral structure, which is tapered from end  200  to end  201  of the structure, in such a way that the narrow end  201  is at the end of the first wing part  9 C and the end of the second wing part  10 C provides a wide end  200  of the tapering. 
       FIG. 15  shows yet another embodiment and the common connection portion  99  wherein first wing part  9 C and the second wing part  100  form an integral structure, which is tapered from end  200  to end  201  of the structure, in such a way that the narrow end  201  is at the end of the first wing part  9 C and the end of the second wing part  10 C provides a wide end  200  of the tapering, and an end face  203  of the wide end is curved. 
       FIG. 17  shows further example of an embodiment of the invention wherein the device has also two wing parts  9 D,  10 D having the common connection portion  100 , the both wing parts,  10 D,  9 D being in a transversal direction with respect to a longitudinal axis  5 A of the displacement source  5 , and having a common longitudinal axis. The both wing parts being directed to opposite directions along the common longitudinal axis. 
     The first wing part  9 D has a tapered form with a wide end and a narrow end, the wide end comprising a part of said connection portion  100 . The wide end is based on a form of semi-circle from where the first wing part tapers towards the narrow end, for example in a parabolic way. The second wing part  10 D has also the semi-circle form, so the semi-circles of the wing parts  9 D,  10 D form a circle, which provides the connection portion. The circle form can be employed to direct the reflections of the mechanical waves (like ultrasound waves) in the structure towards the centre of the circle, and the narrow end of the first wing part  9 D towards the needle tip  4 . Therefore, the energy of the mechanical way can be directed towards the needle tip. The height  170  of the edge of the circle can be the same, lower or higher than the height at the center area of the circler (i.e. at the connection portion). So, the wing parts may thin towards the edges. The structure of  FIG. 17  can have the connection points  11 ,  12  or the connection areas  102 ,  101  as well. 
       FIG. 18  shows yet another embodiment of the structure of  FIG. 17  having the common connection portion  100  wherein first wing part  9 D and the second wing part  10 D form an integral structure. Instead of the circle  181  form provided by the first wing part  9 D and the second wing part  10 D, the form can be another curved form  180 , which can be more near the form of an ellipse or parabolic, like  FIG. 18  illustrates using the dashed lines. In this way a compact structure can be manufactured. As can be noted above the common curves may provide parts of a circle, parts of an elliptic shape, parts of a parabolic shape or even other shapes. 
     So, regarding the examples of  FIGS. 17 and 18 , the first wing part  9 D having the tapered form with the wide end and the narrow end, the wide end comprises a part of said connection portion ( 100 ). The side edges of the wide end can be in a form of a curve  172 ,  173 , like a section or a part of a circle or another curved shape. The side edges  171 ,  174  of the second wing part ( 10 D) can also be in the form of the curve form. The curves  171 ,  174 ,  172 ,  173  of the side edges of the wing parts  9 D,  10 D perform common curves at both sides, and the connection portion  100  is between the common curves (curve  171 ,  174  at one side and curve  172 ,  173  at another side). So, the common curves can provide parts of a circle. Since the curves at both sides integrate at the end of the second wing part  10 D, they provide an integral curved edge that  FIG. 18  clearly illustrates. 
     In the examples of  FIGS. 1 and 2  the displacement source  5  is an ultrasound device having a transducer  62 . The transducer comprises a piezoelectric module  63 , a front part  64 , a back part  65  and a bolt  66  connecting the piezoelectric module. The bolt connects the front part and the back part together in such a way that the piezoelectric module is between the front part and the back part. An ultrasound device has been found to be a convenient displacement source, but other solutions can be used as well. In practice, the front part  64  and back part  65  are mechanically, like acoustically, conducting and electrically isolating. 
     The displacement source can also be a solenoid  161  and its core structure  162  that is connected to an acoustic horn structure  163  for producing, for example ultrasound energy, see  FIG. 16 . The driving signal is connected to the solenoid  161 , which in turn transmits the electric energy via the electromagnetic field to a core structure  162 , which, as said, is connection with the acoustic horn. The core structure moves as response to the changes of the electromagnetic field, and the movements of the core structure moves the acoustic horn. 
     It is said in the above example that at least a part of the wing part in a transversal direction with respect to a longitudinal axis  5 A of the displacement source  5 . It should be note that in this text the term transversal is not restricted to be perpendicular, but also covering other angles as well. A practical embodiment is that an angle range is around the right-angle between the displacement source and the wing part (or its part), let&#39;s say 20 degrees on the both sides of the middle (the right-angle) of the range. 
     As can be noted the inventive mechanical wave inducing device comprises an arrangement for a drive signal that can be formed in many ways. The arrangement for a driving signal can comprise a driving signal connection part  6  in order to connect the displacement source to a signal source as shown in  FIG. 2 . The other arrangement for a driving signal as shown in  FIG. 4  can comprise a battery  41 , a control interface  42 , a controller  43 , a signal generator  44  and an amplification unit  45  in the body part  14 . 
     The inventive device is used for moving the needle tip. The invention can be used with the needles that are used in biopsy including techniques like Fine-Needle Aspiration (FNA) and Core Needle Biopsy (CNB). It is also worth of noting that invention can be used with so called painless needles as well. The movement of the needle tip can alleviate the pain experience when puncturing the needle into the target tissue or contribute to cell, drug, genetic material delivery into organs, tissue or cells. 
     It is worth mentioning that the mechanical waves, longitudinal or transversal, can be standing waves or travelling waves. The standing waves refers to waves when they resonate in a structure, in which cases the peaks and the displacement nodes of the wave typically are located at specific positions. The travelling waves refers to waves that appears to travel, e.g. the displacement peaks move. Further, it is worth mentioning that the material displacement in the longitudinal waves occur within the same direction the mechanical waves are travelling. The material displacement of the transversal waves occurs transversally as compared to the direction of the travelling wave. 
     As can be seen from the examples illustrated above, the inventive device can be made in many ways. For example, the wing parts can be made in multiple ways. The invention may also be used to achieve atomization or nebulization. Atomization or nebulization can be achieved e.g. by selecting frequency and displacement amplitudes so that capillary waves on the liquid droplet surface or cavitation within the droplet are generated. Different needles can be used for different tissue types or pathologies; therefore, different inventive embodiments can be made in order to provide a properly functioning device. 
     It is evident from the above that the invention is not limited to the embodiments described in this text but can be implemented in many other different embodiments within the scope of the independent claims.