AU2004241667A1 - Vibratory transducer for medical imaging and treatment - Google Patents

Description

WO 2004/103179 PCT/AU2004/000680 -1 VIBRATORY TRANSDUCER FOR MEDICAL IMAGING AND TREATMENT Field of the Invention This invention relates to the field of medical apparatus, and particularly apparatus for imaging, and treatment. In particular this invention relates to use of a 5 transducer for such imaging and treatment. This invention has particular application in imaging techniques such as sonoelastography, and treatment of conditions such as osteoporosis and oedemas such as lymphoedema. Background Art 10 Sonoelastography is an ultrasound imaging technique where low amplitude, and low frequency shear waves are propagated through organs and tissue while real time Doppler techniques are used to image the resulting vibration pattern. Hard lesions such as tumours in the presence of soft tissue, such in breast cancer, will have reduced vibration amplitude, which is readily imaged by ultrasonic means. 15 Malignant tumours manifest themselves by way of pathological changes such as variation in the tissue's mechanical stiffness, which can be detected by a reduction in strain as compared to the surrounding soft tissue. An existing technique known as "elastography" is used in breast tumour diagnosis whereby ultrasonic echo data is collected before and after a slight "compression" 20 of the tissue. Comparisons can be made between normal and pathologically affected tissue by gathers information on the static elastic properties of the tissue before and during compression. The differing elastic properties between a benign and malignant tumour can be distinguished by an ultrasound echo detection device. 25 In yet another area of research, it has been documented that a rapidly changing strain or vibration applied to the tissue will result in more defined differences WO 2004/103179 PCT/AU2004/000680 -2 between healthy and pathological tissue. To better distinguish variations in tissue elastic properties, the vibrational frequency response is dependant upon the induced excitation frequency and the amplitude of the vibration source. Variations in tissue motion can be detected by frequency shifts in ultrasonic 5 echoes and imaged using conventional 2D ultrasound scanners and Doppler ultrasound scanners; a method commonly used to highlight blood flow. This invention also has application in treatment of osteoporosis. The skeletal bone structure of a human is considered to be a frameworks of levers upon which muscles are attach to enable movement of the whole body. The skeletal bones 10 are subjected to many varying vibrations due to locomotion, bodily functions, stress, strain and also due to the anchorage of muscle fibres and tendons which are continuously vibrating at different frequencies depending upon the strain applied to them. Bones are subjected to compression influences and vibration during the act of walking, running and jumping and these vibrations reverberate 15 up through the skeletal structure passing through the whole body. It is well documented that bone metabolism is responsive and triggered by mechanical strain. Mechanical loads can be applied through weight bearing exercise or they can be applied by mechanical external sources to the body to cause in vivo deformations of the bone. It is this deformation that signals the 20 bone cells to remodel (rebuild or adapt) the skeletal structure to accommodate the strain applied. This biological phenomenon has long been recognised by physicians for the prevention and treatment of the bone loss condition known as osteoporosis. In the 1890's Julius Wolff a German anatomist, claimed that bone structure could 25 adapt in response to a changing mechanical environment and that the orientation of trabeculae could be changed if there was a change in mechanical stress directions. The biological response of bone to mechanical loading is a complex function and differs according to the individual, the magnitude and the pattern and "direction of the stress" applied. Dynamic mechanical loading leads to interstitial WO 2004/103179 PCT/AU2004/000680 -3 fluid flow within the fluid spaces of bone which plays an important role in providing hydrostatic shear pressure to activate the bone cells into remodelling action. Traditional vibration devices are in the form of one-dimensional acoustic speaker type transducers whereby the vibration is delivered in the form of a linear stroke in 5 the "z" or vertical axis. This form of vibration transducer can vary the frequency output but cannot offer any variation to the mono dimensional amplitude. When used in sonoelastography, the vibration source of this type is required to be repositioned many times during scanning to improve the quality of the 3D mapping reconstruction and to reduce the shadowing effect. Another 10 disadvantage of this form of vibration is that it can generate modal patterns which can make image interpretation difficult. In treatment of osteoporosis, prior art stimulating devices consist of transducer type, vertically moving platforms, which the patient either stands or sits upon. This method applies a compression load to the bones which is converted to a 15 measure of micro-strains by determining the change in the bones length divided by the original bone length. This compression load must be of a significant force to reflect a change in the length of a bones due to the bone matrix being far stronger in compression than in shear. These prior art transducer methods of applying a vertical compressive stress to the skeletal structure have limited 20 success in applying mechanical stimulus to the wider range of bones such as ribs and short plate like pelvic and hip bones to affect a change in bone rebuilding. With this form of shock loading the joints and cartilages must also endure the stress and further transmit the vibration along to the next set of bones for them to benefit from the stress stimulus. 25 It is an object of this invention to provide an alternative to known transducers for use in medical applications, and to provide new methods of imaging and treatment using such alternative transducers. Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to WO 2004/103179 PCT/AU2004/000680 -4 imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Disclosure of the Invention In accordance with one aspect of the invention there is provided, in medical 5 application, use of a vibratory transducer having at least two dimensions of movement available simultaneously, said vibratory transducer having contact surface with a surface area for frictionally coupling to a corresponding surface area of a patient, where movement of said vibratory transducer induces movement in the patient. 10 Also in accordance with a second aspect of the invention there is provided a vibratory transducer for medical application, said vibratory transducer having an armature suspended in a magnetic field, said armature having a plurality of electrical conductive paths to provide electrical current flow in said armature to react with said magnetic field, said vibratory transducer having a contact surface 15 secured to said armature, said contact surface having a surface area for frictionally coupling to a corresponding surface area of a patient, where movement of said vibratory transducer induces movement in the patient, and wherein said transducer can produce movement in said contact surface in at least two dimensions simultaneously. 20 Preferably said at least two dimensions of movement comprises two translational dimensions of movement in a single plane. In one preferred arrangement of either aspect of the invention, the contact surface is toroidal, and encases the patient or part of the patient. Preferably in this form of the invention, the contact surface has an internal configuration adapted to closely 25 conform with the anatomy of the patient, and so maximise the contact area with the patient. In an alternative preferred arrangement of either aspect of the invention, the contact surface is preferably flat. In such an arrangement, the patient will stand, WO 2004/103179 PCT/AU2004/000680 -5 sit, or lie on the contact surface, allowing vibrations to pass from the contact surface to the patient. The effect of having a surface area in contact with the patient is to increase the extent and accuracy of the movement induced in the patient, in two, and especially in three dimensions. 5 Thus, also in accordance with a third aspect of the invention there is provided, in medical application, use of a vibratory transducer having an armature relative to a magnetic flux and producing at least two dimensions of movement in the same plane as said armature, said vibratory transducer having connected with said armature, a contact surface with a surface area for frictionally coupling to a 10 corresponding surface area of a patient, where movement of said vibratory transducer induces movement in the patient. Also, in accordance with a fourth aspect of the invention there is provided, in medical application, use of a vibratory transducer having a platform capable of at least two dimensions of movement relative to a magnetic flux in a single plane 15 containing said platform, said magnetic flux being formed by oppositely disposed magnetic poles, said vibratory transducer having a contact surface with a surface area for frictionally coupling to a corresponding surface area of a patient, where movement of said vibratory transducer induces movement in the patient. Also in accordance with a fifth aspect of the invention there is provided a vibratory 20 transducer for medical application, said vibratory transducer having an armature suspended in a magnetic flux, said armature having a plurality of electrical conductive paths to provide electrical current flow in said armature to react with said magnetic flux, said transducer having a contact surface secured to said armature, said contact surface having a surface area for frictionally coupling to a 25 corresponding surface area of a patient, where movement of said vibratory transducer induces movement in the patient, wherein said transducer produces movement in said contact surface in at least two dimensions. Preferably said at least two dimensions of movement consists of translational movement along x and y axes in a common plane.

WO 2004/103179 PCT/AU2004/000680 -6 Preferably said at least two dimensions of movement includes movement in a third dimension along a z axis normal to said x and y axes. Preferably said medical application is selected from medical imaging such as sonoelastography, and medical treatment such as treatment of oedemas, 5 lymphoedema, muscle and tissue conditions, treatment of bone breakage, fractures, and osteoporosis. Brief Description of the Drawings Several preferred embodiments of the invention will now be described in the following description made with reference to the drawings, in which: 10 Figure 1 is a perspective view, partly cut-away, showing apparatus according to a first embodiment used in a method of treating osteoporosis, lymphoedema and for sonoelastography imaging; Figure 2 is a perspective view, partly cut-away, showing apparatus according to a second embodiment used in a method of treating osteoporosis or 15 oedemas, lymphoedema, muscle and tissue conditions, and treatment of bone breakages and fractures, and for sonoelastography imaging; Figure 3 is a perspective view, partly cut-away, showing apparatus according to a third embodiment used in a method of treating osteoporosis or oedemas, lymphoedema, muscle and tissue conditions, and treatment of bone 20 breakages and fractures, and for sonoelastography imaging; Figure 4 is a perspective view, partly cut-away, showing apparatus according to a fourth embodiment used in a method of treating osteoporosis or oedemas, lymphoedema, muscle and tissue conditions, and treatment of bone breakages and fractures, and for sonoelastography imaging; 25 Figure 5 is a perspective view, partly cut-away, showing apparatus according to a fifth embodiment used in a method of sonoelastographic analysis, treatment of oedemas, lymphoedema, muscle and tissue conditions, and treatment of bone breakages and fractures and osteoporosis; Figure 6 is a side elevation, partly cut-away, showing -apparatus according 30 to the fifth embodiment; Figure 7 is a side elevation, partly cut-away, showing apparatus according WO 2004/103179 PCT/AU2004/000680 -7 to a sixth embodiment used in a method of sonoelastographic analysis and treatment of oedemas, lymphoedema, muscle and tissue conditions, and osteoporosis; and Figure 8 is a side elevation, partly cut-away, showing apparatus according 5 to a seventh embodiment used in a method of sonoelastographic analysis and treatment of oedemas, lymphoedema, muscle and tissue conditions, and osteoporosis. Best Mode(s) for Carrying Out the Invention The transducer 10 employed in the apparatus and the method of the 10 embodiments has an annular permanent magnet 12 and an armature formed from a disk 14 in the form of a wheel. The permanent magnet 12 is a Cockcroft ring with a C-shaped cross section, having a gap 18 in which the outer circumference of the disk is disposed, and through which lines of magnetic flux flow. The armature has a central hub 20 connected to the disk 14 by six radial arms 22. 15 The arms 22 each have a transformer 24 mounted thereon. The armature is formed of a metal, preferably non-magnetic. By controlling the current flow in each of the transformers 24, current can be induced to flow in the disk 14 (via adjacent arms 22 and the connecting portion of the hub). By inducing current flow in a controlled manner, movement can be induced in the armature, in the x and y 20 axes in the plane of the armature. Furthermore complex two dimensional patterns of movement in the armature can be achieved, through control of current to the six transformers 24. While the embodiments are described with reference to.this particular transducer, it should be understood that variations to the construction of the transducer may be made without affecting the operation of the invention. For 25 example, the annular permanent magnet may be segmented in structure, and indeed the construction of the transducer may be that the annulus of the transducer may be divided, perhaps hingeably, for access. The electrical conductive paths may be supplied with electric current by a means other than transformers, and the number of arms 22 and hence transformers or current paths 30 or other means of interacting with the lines of magnetic flux, may be varied.

WO 2004/103179 PCT/AU2004/000680 -8 Embodiments of the invention can be used in the field of sonoelastography to provide a vibration device capable of inducing at least a two-dimensional motion into tissue during ultrasonic imaging. The vibration source and overall system is provided by an electric motor described in US 6,160,328, the contents of which 5 are incorporated herein by cross-reference. The motor is capable at a minimum of two-dimensional motion with variable frequency and variable amplitude patterns in a common X-Y planar path. One embodiment of the motor is also capable of three-dimensional motion (vibration) with variable frequency and variable amplitude patterns in a common X-Y planar path along with a Z axis oscillations. 10 In an alternative embodiment, the vibration source and overall system can be provided by an electric motor described in US 6,703,724, the contents of which are also incorporated herein by cross-reference. Embodiments of the invention can also be used in a passive method of mechanically loading human bones with a dynamic planar two-dimensional motion 15 for the treatment and prevention of osteoporosis and for fracture healing of bone tissue. In application for treatment of bone, the mechanical strain applied is in the form of flexure with the amplitude being applied substantially perpendicular to the upright skeleton. The person being treated whilst uprightly positioned on the moving platform will endure a sense of vibration radiating up through their body. 20 As will be described below, the coupling between the vibrating platform and the tissue may be by way of direct contact with the platform, or through an adjustable bellow (foam, air etc) or any other form of size and shape conforming substance, which surrounds the tissue, limb, or body part. Where the tissue, limb, or body part is surrounded, it is most preferred that the bellow is capable of forming a firm 25 fit, so as to maximise the transcutaneous transfer of vibrational energy. In it simplest two-dimensional form, the present invention does not utilise a vertical oscillating transducer to impart a compressive stress into the tissue. It utilises a gentle non-rotating X-Y planetary action to provide radial loads and 360 degree flexure of muscle and tissue, This vibratory motion may be in the form of 30 a planetary action that is set at a given eccentric distance (radius off centre = WO 2004/103179 PCT/AU2004/000680 -9 amplitude) and oscillated at a selectable frequency in the sonic range (below 20kHz). The two dimensional motion (x y plane) will impart a flexure response to the tissue mass which will, in turn, stimulate the tissue matrix with a full 360 degree moment. 5 The invention can provide a passive method of mechanically loading tissue with a dynamic planar two-dimensional motion for the imaging diagnosis of tumours and lesions within the human body. The invention has the capability to impart a myriad of strain vibrations at various amplitudes and/or frequencies and/or in various directions. The mechanical stress applied by the present invention is 10 transferred into strain within the tissue or organ. Applying the stress in two and/or three dimensions simultaneously, results in a better diagnostic interpolation of the tissue condition. Referring to Figure 1, the first embodiment shows apparatus used in a method of treating osteoporosis. The apparatus has a contact surface 26 on which a person 15 28 can stand. The contact surface is formed of a metal or non metal plate supported in insulating manner on circumferential rings 30 on the central hub 20 of the armature, and on the arms 22 adjacent the transformers 24, so that movement induced in the armature is transmitted to the contact surface 26. A microprocessor based controller 32 is mounted on a support frame 34, so that the 20 movement of the armature can be programmed. Referring to Figure 2, the transducer 10 is mounted with its central axis disposed horizontally, so that a patient 28 can insert their leg 34, through the central hub 20. The apparatus shown in Figure 2, which is intended to treat osteoporosis or lymphoedema includes the contact surface incorporated in bellows 36 formed of a 25 composite foam rubber with inflatable cells, which is firmly fixed to the central hub 20 of the transducer 10. Once the patient 28 has inserted their limb (in this case leg 24), the bellows 36 is inflated to tightly restrain the limb. The transducer 10 is mounted in a chassis 38, located at an appropriate level so that the patient 28 can be positioned seated in a chair 40. The controller 32 is conveniently located on 30 the chassis 38, so that movement of the transducer can be programmed.

WO 2004/103179 PCT/AU2004/000680 -10 Referring now to Figure 3, the third embodiment, also intended for treatment of osteoporosis, oedemas, muscle and tissue conditions and treatment of bone breakage and fractures or lymphoedema is shown. The third embodiment differs from the second embodiment insofar as that there are two identical transducers 5 10 with bellows 36 located side by side in coaxial manner. This arrangement allows for more complex patterns of vibration to be induced in the patient 28. Referring now to Figure 4, a fourth embodiment is shown for treatment of osteoporosis or lymphoedema, oedemas, muscle and tissue conditions and treatment of bone breakage and fractures and / or sonoelastography imaging;. 10 This embodiment differs in that it is mounted in a support frame which disposes a transducer 10 at a suitable height to receive the arm 44 of the patient 28, whilst standing. Referring to Figures 5 and 6, the fifth embodiment is shown, which is shown being used in sonoelastography to induce vibration through the contact surface in the 15 form of bellows 36, in a patient undergoing imaging by Doppler, ultrasound or magnetic resonance. In use, the patient lies through the bellows 36, resting on the bellows 36 with the region of their anatomy to undergo imaging, in close proximity to the bellows 36. This embodiment is also suitable for the treating of osteoporosis, muscle and tissue conditions or lymphoedema. 20 It should be noted that each of the embodiments has been shown cut away, so that internal details of the transducers can be seen. It will be understood that the transducer 10 is a circular device, the permanent magnet 12 being a full annulus, and the bellows completely surrounding the limb or body part to be imaged. The transducer can be constructed so as to be dividable, for transport. The 25 embodiments shown in figures 2 to 4 may be constructed so that the transducers can be divided, perhaps hingeably, so that the patient's limb can be easily inserted and removed. In the case of the first embodiment, it should be noted that the contact surface 26 is also a complete disk. The sixth embodiment shown in Figure 7 is a cross section view showing the 30 transducer 10 lying horizontally. The contact surface 26 is provided as a plate 46 WO 2004/103179 PCT/AU2004/000680 -11 supported on a circumferential ring 48, which rests on the armature. In turn, the armature is supported on flexible rubber mounts 50, which allow for resilient movement of the armature. Referring to Figure 8, the seventh embodiment is shown, being a transducer 10 5 fitted with a bellows 36 having a shape conforming to and capable of receiving (by encircling) a female breast for performing sonoelastographic analysis. The two dimensional vibration induced in the transducer 10 is transcutaneously applied to the tissue region of the breast tissue for tumour diagnosis. In an alternative embodiment, two transducers may be employed simultaneously to compare strain 10 differences between the two breasts. Sonoelastographic scanning requires the vibration source to be optimised to the correct frequency range to suit the tissue being diagnosed. The embodiment, through the controller, offers this feature by imparting a dynamically tuneable, nonphysiological mechanical stimulation to the tissue in the form of a two 15 dimensional oscillatory / vibratory motion. The tissues natural frequency differs by varying degrees for all individuals, with consideration given to the individuals muscle suppleness which is more likely to be a reflection of their age or their disease condition. It is therefore advantageous for broadest application, to have a dynamically variable stimulation device with the 20 capacity to tune the amplitude of vibration and/or the frequency rate whilst the patient is being treated. In treatment of bone disorders, the mechanical stimulation sets up vibrations in the tissue matrix which will inturn be filtered down to the bone cells. At the cellular level of the bone the signal must be strong enough to apply a flexure strain to the 25 bone so as the bone adaptation process can commence. The bone adaptation process differs by varying degrees for all individuals, with consideration given to their existing bone density and their bone suppleness, which is likely to be a reflection of age or disease. It is therefore necessary to have a dynamically variable stimulation platform with the capacity to tune the amplitude of vibration or 30 the frequency rate whilst the patient is being treated.

WO 2004/103179 PCT/AU2004/000680 -12 The invention utilises the knowledge that bones respond to "non-routine loads" far better than customary loads. The mechanical stimuli and therefore the bone adaptation would be more effective if it were site specific due to the differing properties and natural frequencies of various bones. The use of embodiments 5 such as those illustrated in figures 2, 3, 4, and 7 provides for this. Through the controller 32, there is provided the ability to tune the vibration stimulus to suit the patient by dynamically varying the planetary action without the need to stop the machine whilst the patient is being treated. This can be achieved by dynamically tuning the vibration to the optimal frequency range(s) and 10 amplitude(s), and to change the vibration pattern in a single plane. Typical frequencies envisaged are any frequency from 10 or 20 Hz up to 20kHz, with displacement of from 0.005mm or 0.1mm up to 50mm. The vibratory pattern can alternate between a variable "orbit pattern" to a "linear oscillating pattern" and back to an orbital pattern without a pause in the treatment. 15 This tuning can impart an optimised stimulus to more accurately reflect the difference between normal tissue and pathological tissue for various parts of the body whilst being imaged by a Doppler, ultrasound, magnetic resonance or any other imaging device. The orbital diameter and the linear stroke are completely variable in their 20 amplitudes and can be applied at any desired frequency rate. The linear oscillations can be directed in any radial X-Y component direction in a 360 degree arc, to best direct the strain effect upon a selected lesion area. This multi pattern two-dimensional motion can be infinitely varied to change the strain characteristics received by the tissue to bring about a greater variation in signal 25 feed back to the data correlation equipment. The motion platform can track a prescribed motion in the form of a "figure of eight" or a "clover leaf", or any "perturbed pattern" that will impart a certain node of stimulation to the tissue or bone. In the treatment of bone disorders, the ability to change the two dimensional planar/orbital motion changes the strain characteristics which are 30 received by the cell tissue of the bone, and brings about a greater change in bone rebuilding.

WO 2004/103179 PCT/AU2004/000680 -13 Similarly, the controller 32, has the ability to dynamically change the platform's motion pattern in a single plane whilst a patient is lying on an examination table, being treated. The motion platform can alternate between a linear oscillating pattern in a direction of the patient's head and feet (by example) and then switch 5 to a tangential side to side direction or any revolving star like linear pattern around a circle. These features enable the physician to apply the stress in a direction that will apply the desired strain to a tissue to optimise the imaged response. In bone treatment, this allows the physician to direct the dynamic stress where it can apply the desired strain to suit a particular bones orientation. The linear stroke is 10 variable in its amplitude and can be applied at any desired frequency. The use of the bellow or cuff provides the ability for the device to be located site specific along the body. By cuffing/encircling around a wrist or arm or leg or the hips or chest or vertebrae, it is ensured that stimulus is received by the bone tissue being targeted for treatment. Hip fractures in particular are very prevalent in 15 the elderly and this invention enables site specific stimulus to that region to aid in reducing the effects of osteoporosis and osteopenia conditions. Other medical application found for the vibratory transducer is to extend the life of blood platelets in storage beyond the current five day maximum period. With optimal controlled vibration, oxygen transfer to the platelets can be maximised 20 while reducing sheer-force damage, and so maximising the life of the platelets. Blood platelets are important in treatment following therapy such as chemotherapy. It should be appreciated that the scope of the invention is not limited to the particular embodiment disclosed herein. 25

Claims (21)

1. Use of a vibratory transducer in medical application, said vibratory transducer having at least two dimensions of movement available simultaneously, said vibratory transducer having contact surface with a surface area for frictionally 5 coupling to a corresponding surface area of a patient, where movement of said vibratory transducer induces movement in the patient.

2. Use of a vibratory transducer in medical application as claimed in claim 1 wherein said at least two dimensions of movement comprises two translational dimensions of movement in a single plane. 10

3. Use of a vibratory transducer in medical application as claimed in claim 1 or 2 wherein the contact surface is toroidal, and encases the patient or part of the patient.

4. Use of a vibratory transducer in medical application as claimed in claim 3 wherein the contact surface has an internal configuration adapted to closely 15 conform with the anatomy of the patient, and so maximise the contact area with the patient.

5. Use of a vibratory transducer in medical application as claimed in claim 1 or 2 wherein the contact surface is substantially flat, wherein the patient stands, sits, or lies on the contact surface, allowing vibrations to pass from the contact 20 surface to the patient.

6. A vibratory transducer for medical application, said vibratory transducer having an armature suspended in a magnetic field, said armature having a plurality of electrical conductive paths to provide electrical current flow in said armature to react with said magnetic field, said vibratory transducer having a 25 contact surface secured to said armature, said contact surface having a surface area for frictionally coupling to a corresponding surface area of a patient, where movement of said vibratory transducer induces movement in WO 2004/103179 PCT/AU2004/000680 -15 the patient, and wherein said transducer can produce movement in said contact surface in at least two dimensions simultaneously.

7. A vibratory transducer for medical application as claimed in claim 6 wherein the contact surface is toroidal, and encases the patient or part of the patient. 5

8. A vibratory transducer for medical application as claimed in claim 7 wherein the contact surface has an internal configuration adapted to closely conform with the anatomy of the patient, and so maximise the contact area with the patient.

9. A vibratory transducer for medical application as claimed in claim 7 or 8 10 wherein the contact surface is located on an inflatable bellows which may be inflated to urge contact of the contact surface with the patient.

10. A vibratory transducer for medical application as claimed in claim 6 wherein the contact surface is flat and disposed to allow the patient to stand, sit, or lie on the contact surface, to allow vibratory motion to pass from the contact 15 surface to the patient.

11. Use of a vibratory transducer in medical application, said vibratory transducer having an armature disposed relative to a magnetic flux and producing at least two dimensions of movement in the same plane as said armature, said vibratory transducer having connected with said armature, a contact surface 20 with a surface area for frictionally coupling to a corresponding surface area of a patient, where movement of said vibratory transducer induces movement in the patient.

12. Use of a vibratory transducer in medical application, said vibratory transducer having a platform capable of at least two dimensions of movement relative to 25 a magnetic flux in a single plane containing said platform, said magnetic flux being formed by oppositely disposed magnetic poles, said vibratory transducer having a contact surface with a surface area for frictionally WO 2004/103179 PCT/AU2004/000680 -16 coupling to a corresponding surface area of a patient, where movement of said vibratory transducer induces movement in the patient.

13. A vibratory transducer for medical application, said vibratory transducer having an armature suspended in a magnetic flux, said armature having a 5 plurality of electrical conductive paths to provide electrical current flow in said armature to react with said magnetic flux, said transducer having a contact surface secured to said armature, said contact surface having a surface area for frictionally coupling to a corresponding surface area of a patient, where movement of said vibratory transducer induces movement in the patient, 10 wherein said transducer produces movement in said contact surface in at least two dimensions.

14. A vibratory transducer for medical application as claimed in claim 13 wherein said at least two dimensions of movement consists of translational movement along x and y axes in a common plane.

15 15. A vibratory transducer for medical application as claimed in claim 13 wherein said at least two dimensions of movement includes movement in a third dimension along a z axis normal to said x and y axes.

16. Use of a vibratory transducer for medical application as claimed in any one of claims 1 to 4, 10 and 11 wherein said medical application is selected from 20 medical imaging such as sonoelastography, and medical treatment such as treatment of oedemas, lymphoedema, muscle and tissue conditions, treatment of bone breakage, fractures, and osteoporosis.

17. A method of treatment for a medical condition including oedemas, lymphoedema, muscle and tissue conditions, bone breakage, fractures, and 25 osteoporosis, using a vibratory transducer as claimed in any one of claims 6 to 10 , and 13 to 15 , said vibratory transducer contact surface contacting tissue in proximity to or surrounding the medical condition treatment site. WO 2004/103179 PCT/AU2004/000680 -17

18. Apparatus for medical application having at least two vibratory transducers as claimed in any one of claims 7 to 9 , wherein said vibratory transducers are located coaxially spaced apart, and side by side, to receive the patient or part of the patient such as a limb, therethrough. 5

19. A vibratory transducer for medical application substantially as herein described with reference to the drawings.

20. Use of a vibratory transducer for medical application substantially as herein described with reference to the drawings.

21. A method of treatment for a medical condition substantially as herein 10 described with reference to the drawings.