Patent ID: 12194650

DESCRIPTION OF EMBODIMENT

Hereinafter, the embodiment of the present invention will be described with reference to the drawings.

As illustrated inFIG.1, a handpiece-type high-frequency vibration apparatus as one embodiment of the present invention comprises a roughly cylindrical housing10configuring a handpiece, a holding member11, a tool12, a controller20and an excitation device21.

The housing10is designed in a size to be held in one hand by an ordinary person. The handpiece of a high-frequency vibration-type cutting device is configured by components such as the housing10and the holding member11at least partially arranged in the internal space, and kinds and specifications of the components may be appropriately selected from a viewpoint of reducing weight of the handpiece for handling convenience.

The holding member11is attached to the excitation device21at the rear end portion, and is supported freely movably in an axial direction to the housing10via support portions112and114fixed to an inner side wall of the housing10. The holding member11has a function as a horn which increases amplitude. The tool12is freely detachably attached to a distal end portion of the holding member11.

A length of the tool12in a direction perpendicular to the axial direction of the holding member11is 30-150 [mm]. Examples of the kind of the tool12are a curette, a chisel, a surgical knife, a file, a long type and a short type. In addition, as a shape of the tool12, an arbitrary shape such as a blade with a straight or circular arcuate distal end, a roughly columnar shape, a spoon shape, or a bent or curved rod shape is adopted.

The excitation device21is attached to an attaching portion10aof the housing10, is configured by a piezoelectric element arranged in the internal space of the housing10, and vibrates or reciprocatingly drives the holding member11in the axial direction. Electric power is supplied to the excitation device21via a cable24attached to the rear end portion of the housing10and the controller20and a conducting wire arranged in the internal space of the housing10.

Since the excitation device21and the holding member11are arranged such that respective axes are in common and separated in relation to the respective axial directions, compared to a case where the axes are separated in parallel or arranged in non-parallel, an occupancy space of the excitation device21and the holding member11in the internal space of the housing10, and eventually the housing10, can be made compact in relation to the direction perpendicular to the axes. Thus, the high-frequency vibration-type cutting device can be configured as the handpiece for which holding comfortableness and operability are improved.

Since force of the excitation device21is directly transmitted to the holding member11without use of a transmission mechanism, need of lubricant such as grease generally used for the transmission mechanism is eliminated Thus, in the case where the high-frequency vibration-type cutting device as a medical appliance is sterilized by high-pressure steam, a situation where contamination of the medical appliance resulting from presence of the lubricant occurs is avoided.

The controller20controls an operation of the excitation device21. A microcomputer or a processor configuring the controller20is arranged in the internal space of the housing10together with a substrate on which the microcomputer or the processor is mounted. The controller20performs control so that a vibration frequency f2in the axial direction of the tool12via the holding member11by the excitation device21is included in a range of 20-60 [kHz]. It is more preferable that the control be performed to be f2=25-45 [kHz].

According to the handpiece-type high-frequency vibration apparatus of the configuration described above, by the holding member11being reciprocatingly driven in the axial direction, the object is cut by the tool12provided on the distal end portion of the holding member11.

Effects

In the case of cutting the object using the handpiece-type high-frequency vibration apparatus, an operator who performs cutting (surgery) attaches the tool12to the distal end portion of the holding member11. Then, the operator vibrates the holding member11(the tool12) in the axial direction before cutting tissue, a bone in an ear, for example, of a patient as the object by the tool12(a non-contact state).

The controller20detects a first resonance frequency fr1of the tool12in the non-contact state by a detector (not illustrated). Then, the controller20drives the excitation device21so as to vibrate the tool12at an added frequency fp for which a predetermined frequency fs (to be described later in detail) is added to the first resonance frequency fr1(energizes a pulse current corresponding to the added frequency fp to the excitation device21) (a vibrating step).

Thus, as illustrated by a dotted line inFIG.2, since the tool12is vibrated at the added frequency fp higher than the first resonance frequency fr1in the non-contact state, in the case where the tool12is vibrated at the first resonance frequency fr1, a difference from a resonance frequency is generated, so that vibrating energy becomes low and heat quantity generated by the tool12can be reduced. Thus, in the case where the tool12is brought into contact with biological tissues (the biological tissues in the ear) around the object, deterioration or damage of the biological tissues is suppressed.

When the tool12is brought into contact with the object (a contact state), as a load applied to the tool12increases, a second resonance frequency fr2of the tool12in the contact state increases and approaches the added frequency fp. That is, since the difference from the resonance frequency of the tool12is reduced, the vibrating energy increases.

In a cutting state where the tool12is in contact with the object by the load that enables cutting of the object by the tool12, the controller20controls drive of the excitation device21such that a third resonance frequency fr3of the tool12in the cutting state increases and coincides with the added frequency fp (a cutting step). Also in the cutting state, the tool12is vibrated at the added frequency fp. In the present embodiment, for the predetermined frequency fs, a frequency that enables the third resonance frequency fr3to coincide with the added frequency fp is set. Without being limited to the coincidence, the third resonance frequency fr3may be made to approach the added frequency fp.

Thus, as illustrated by a solid line inFIG.2, in the cutting state, since the tool12can be vibrated at the third resonance frequency fr3(added frequency fp), the object can be cut with high cutting energy without causing vibration attenuation by the load to the tool12and cutting efficiency is high.

Note that the predetermined frequency fs may be settable by the operator. For example, the operator with strong force of pressing the tool12to the object when cutting makes the predetermined frequency fs higher than a threshold, and the operator with weak force of pressing the tool12to the object when cutting makes the predetermined frequency fs lower than the threshold. Thus, the appropriate predetermined frequency according to a type of the operator can be attained.

In the present embodiment, between the contact state and the cutting state, the drive of the excitation device21is controlled so as to increase the resonance frequency of the tool12according to increase of the load of the tool12in contact with the object. That is, the cutting energy increases according to the increase of the force (the force of pressing the tool12to the object) applied by the operator.

Conventionally, when a bone curette is used, for instance, as the tool12, a cutting amount of the bone (object) is controlled by force adjustment of the operator. In the present embodiment, since the cutting energy (oscillation power) increases according to the force adjustment applied by the operator, the force to be applied can be reduced while utilizing a past operator sensation, and delicate work can be supported without stress.

In addition, in the case of cutting the object (the bone) in water while securing an operating field using an endoscope, when the cutting energy of the tool12is high, since the water around the tool12is largely shaken and bone dust and soft tissues are shaken by a water current, a visual field of the endoscope is obstructed, however, according to the present embodiment, workability is improved since the cutting energy is suppressed until right before cutting the bone.

The ideal embodiment of the present invention has been described above, however, the present invention is not limited by such an embodiment, and appropriate modifications are possible without departing from the gist of the present invention.

For example, while the first resonance frequency fr1of the tool12in the non-contact state is detected by the detector in the embodiment described above, the first resonance frequency fr1of each of the two or more kinds of tools12may be stored in a memory (not illustrated) beforehand and the controller20may read the first resonance frequency fr1from the memory according to the kind of the tool12attached to the distal end portion of the holding member11.

In this case, the handpiece-type high-frequency vibration apparatus further comprises an input interface for making the operator input the kind of the tool12. The input interface is configured by a keyboard, touch panel-type button or an operation button or the like, for example.

REFERENCE SIGNS LIST

10. . . Housing,11. . . Holding member,12. . . Tool,20. . . Controller,21. . . Excitation device