CN201263707Y - Medical ultrasound amplifying device - Google Patents

Abstract

The utility model relates to a medical ultrasound amplifying device which comprises an amplitude transformer and a terminal actor, wherein the amplitude transformer is connected with the terminal actor; the amplitude transformer comprises a shaft structure and a plurality of single horns or various horns; the profile sections of horn bodies change according to the rule of a mathematic function; the length of the shaft structure and the horn bodies both approaches one fourth wavelength or odd times of one fourth wavelength of work frequencies. The medical ultrasound amplifying device improves stress, improves vibration speed, and prolongs the service life.

Description

A kind of medical supersonic amplifying device

Technical field

This utility model relates to the ultrasonic medical instrument technical field, and the ultrasonic surgical instruments of cutting preferably and hemostatic function is especially arranged.Particularly, be a kind ofly to have the ultrasonic amplitude transformer of a plurality of single or multiple loudspeaker and have the medical supersonic amplifying device that amplifies amplitude and vibration velocity effect.

Background technology

In surgical operation, how to stop the rupture of blood vessel that causes when cleavage activity is organized and bleed one to being the problem of surgeon than headache, traditional method is to tie up trunk by suture to realize, but there are a large amount of little blood vessels, bleeding because of tying up one by one still, a kind of ancient method that follows so far is by adding these little blood vessels of thermal burn, it is solidified and reaches the hemostatic purpose.

Electric knife has appearred in the development along with technology, and is applied in surgical operation.Electric knife when cutting and organizing, thereby burn this portion of tissue to reach haemostatic effect because of electric current can produce heat by facet.But electric knife is bigger to the damage of tissue, and it can dryout the moisture in the facet tissue, sometimes even burn these tissues.

Recently, introduced a kind of new medical apparatus and instruments---ultrasound knife again in surgical operation, it has cutting and hemostatic function preferably.These apparatus front-end functionality parts (abbreviation cutter head) cut and organize by altofrequency vibration, simultaneously and organize fricative heat can play good haemostatic effect to facet, and to the damage of tissue also than little many of traditional method.

The ultrasound knife operation principle is roughly: earlier by system with driving source or generator produce the high-frequency ac signal of telecommunication, be input to another parts ultrasonic transducer of system then, transducer is converted to the ac signal of input the mechanical vibration of the main standing wave form of longitudinally propagating by effects such as piezoelectricity or magnetostriction.In general; the initial Oscillation Amplitude (abbreviation amplitude) of transducer does not often reach instructions for use; the amplifier (abbreviation horn) that for this reason can add one or more horn structures usually amplifies amplitude, by waveguide it is delivered to cutter head at last, realizes the function that needs.The length sum of transducer and end effector requires to be designed to half the integral multiple of frequency institute corresponding wavelength of job demand, and system could do the mechanical vibration of vertical standing wave form with the frequency of needs like this.In case of necessity, end effector can add some single or complex horns amplitude is further amplified, and up to needed value, repeated transmission is passed cutter head.In order to realize different functions, cutter head can be made various shape.Ultrasound knife is exactly cutting and a hemostatic of utilizing the vibration effect of end effector and functional part thereof to organize.This apparatus has obtained the application of certain limit in the surgical operation of endoscope type.A kind of horn structure as shown in Figure 3, horn is a stairstepping partly, comprises the axle construction 11,12 that two sections diameters do not wait; Fig. 5 shows another kind of horn structure, and it is one section conical section 21.

The cutting of ultrasound knife is relevant with the cutter head vibration with haemostatic effect, exactly, is relevant with its vibration velocity.Yet, run counter between cutting and the hemostasis.If cutter head is enough sharp, the speed of cutting can be very fast, and this is that the doctor wants, and still insufficient is possible not produce the required enough heats that stop blooding at short notice, and vice versa.But when vibration velocity improves, reduce the cutting dynamics and/or strengthen haemostatic effect still can obtain by changing the cutter head shape.Comprehensive each side considers that cutting speed still has certain practical significance faster.

For the consideration of operative connection, people wish that always the vibration velocity of ultrasound knife can break through 17.4m/s.The vibration velocity and the amplitude of ultrasound knife are directly proportional, and the stress of amplitude and equipment is to be directly proportional, and simultaneously, the probability of cutter head fatigue failure also always is directly proportional with stress.In traditional technology and method, although can improve vibration velocity by the amplitude that improves the ultrasound knife ad-hoc location, but this is worthless, because the stress on the equipment has also increased, may exceed its safe handling scope, influenced the function and the service life of ultrasound knife, speed promotes the fraud that stress brought that the profit of bringing is less than to be increased on the ultrasound knife structure thereupon.For the consideration of both pros and cons of balance, the vibration velocity of ultrasound knife is limited in below the 17.4m/s usually, and when promptly being equivalent to operating frequency and being 55.5KHz, amplitude is less than 100 microns.The ultrasound knife vibration velocity of actual usefulness mostly is 15.7m/s, and amplitude is 90 microns when promptly being equivalent to operating frequency and being 55.5KHz, sometimes even littler.As from the foregoing, if can provide vibration velocity to continue greater than 17.4m/s, the while is the ultrasound knife of proof stress in apparatus safe handling scope again, and that will be of great practical value.

The utility model content

The purpose of this utility model is to provide a kind of ultrasonic amplifying device, the horn that comprises a plurality of single loudspeaker or multiple loudspeaker by employing, make in the quarter-wave segment limit of a wavelength, keep the heavily stressed of equipment and arrive certain level, when improving amplitude, reach the purpose that improves vibration velocity, but each stress point is in still below the S-N curve (stress causes the fatigue failure curve).

For reaching above purpose, solution of the present utility model is:

A kind of medical supersonic amplifying device, it comprises horn and end effector, horn is connected with end effector, this horn is made of axle construction and/or one or more horn bodies, the horn body longitudinal section changes by the rule of certain mathematical function, and this function is notch cuttype, exponential type, pyramid type, Bezier type, Gaussian curve type or suspension cable shaped form.

Further, its head shaft structure front end is connected with transducer mount, and the rear end is connected with the horn body of longitudinal section gradual change, and horn body links to each other with end effector again.

The length of this axle construction and horn body during all near operating frequency 1/4 wavelength or the odd-multiple of 1/4 wavelength.

This horn body near the cross-sectional area of head shaft structure one end greater than cross-sectional area near the other end of tail end.

The geometry of this horn body can be notch cuttype, exponential type, pyramid type, suspension cable shaped form, Gaussian curve type and Bezier type according to actual needs.

The cross section of this horn is generally circle, square or rectangle.

Its material is titanium or titanium alloy, aluminum and aluminium alloy, pottery or rustless steel.

Its employed ultrasound waveguide resonant frequency is 20kHz～100kHz.

Owing to adopted above technical scheme, the utlity model has following advantage: this utility model comprises the horn of a plurality of single loudspeaker or multiple loudspeaker by employing, make this ultrasonic amplifying device in the quarter-wave segment limit of a wavelength, keep a high stress level, but each stress point still is in below the S-N curve, when improving vibration equipment speed, also guaranteed its service life, made ultrasound knife in the safe handling scope, have ideal cutting and haemostatic effect.

Description of drawings

Fig. 1 is this utility model structural representation;

Fig. 2 causes the fatigue failure curve chart according to the stress that this utility model embodiment draws;

Fig. 3 is traditional stepped ultrasonic transformer structural representation;

Fig. 4 is traditional stepped ultrasonic transformer diagram of strains;

Fig. 5 is traditional conical horn structural representation;

Fig. 6 is traditional conical horn diagram of strains;

Fig. 7 is this utility model complex horn structural representation;

Fig. 8 is this utility model complex horn diagram of strains.

The specific embodiment

Below in conjunction with the accompanying drawing illustrated embodiment this utility model is further described.

This utility model can directly apply to ultrasonic medical instrument equipment, is specially adapted to have the ultrasonic surgical instruments of cutting and hemostatic function, but is not limited only to this kind equipment.Its main feature is: this ultrasonic amplifying device comprises horn and end effector 4, horn contains one or more horn bodies, the vertical sectional shape of horn body is for changing by certain mathematical function rule, and this function can be notch cuttype, exponential type, pyramid type, Bezier type, Gaussian curve type or suspension cable shaped form etc.

Its operation principle is as follows:

The speed of vibration and amplitude and frequency have following relation:

V＝2πaf (1)

Wherein: V-vibration velocity (m/s)

A-Oscillation Amplitude (m)

F-frequency of vibration (Hz)

It seems that from this relational expression frequency one regularly can change vibration velocity by adjusting amplitude.

Again, the relation of amplitude and stress is as follows:

$a=2\·{\∫}_0^{\frac{1}{4}\·\mathrm{\λ}}\mathrm{\ϵ}\left(x\right)\mathrm{dx}---\left(2\right)$

This relational expression is that zero node definition is x=0 with the middle amplitude of horn, 1/4 λ is the quarter-wave segment limit, ε (x) is that device vertically is the strain size of x apart from node node (position of amplitude minimum) distance, stepped ultrasonic transformer for half-wavelength, node is just in the centre position, for the conical horn of half-wavelength, node is the off-center position slightly, to the little field offset in cross section.

Therefore, the stress of device also can increase when amplitude increased, and can be index decreased the service life of device, so this high vibration velocity and unrealistic of merely pursuing.

Stress causes the fatigue failure curve as shown in Figure 2, and this curve also is called the S-N curve.

In Fig. 2, vertical coordinate 5 representation unit area stress intensities, abscissa 6 is represented service life, extensional vibration cycle-index when promptly installing fatigue failure.Curve 7 is S-N curve (stress causes the fatigue failure curve), and it has described the fatigue limit (promptly use life-span) of device materials under given applied stress.When stress is lower than the S-N curve when following, device generally can be because of fatigue of materials lose efficacy, otherwise when stress is higher than the S-N curve when above, device can be stressed excessive because of material, finally lost efficacy because of tired.For some material, titanium for example, when stress is low to a certain degree the time, can reach endless its service life in theory.

For the medical apparatus and instruments that this utility model relates to, generally require its fatigue failure cycle-index to reach 108, for titanium alloy, corresponding dependent variable needs less than 0.0033mm/mm.

This utility model adopts the heavily stressed certain level that arrives of holdout device in the last quarter-wave segment limit of a wavelength, but still be in below the S-N curve, under the prerequisite that guarantees service life of equipment, make its vibration velocity surpass 17.4 meter per seconds simultaneously, good cutting and haemostatic effect is provided.

In ultrasonic amplifying device, horn body commonly used is divided into 6 kinds on notch cuttype, exponential type, pyramid type, suspension cable shaped form, Bezier type and Gaussian curve type by its geometry, for the ease of processing, their cross section is done quadrate, rectangle or circle usually.Every kind of loudspeaker have different effects because of the difference of its physical characteristic in Vltrasonic device.The horn that difform loudspeaker form has different strain curves.Fig. 4 and Fig. 6 are respectively horn,stepped and pyramid type horn mimic strain curve figure on finite element software of certain parameter, as can be seen from the figure, the strain curve of horn,stepped produces a projection, surpassed strain limit, and the strain curve of conical horn is relatively mild.Therefore, horn,stepped uses as amplifier, under the identical situation of sectional area ratio, although its amplification maximum produces a sharp wave fast in strain; Conical horn is vertically but having amplification relatively gently, but amplification is not as horn,stepped.

In Vltrasonic device, if its length surpasses a wavelength, in order to improve vibration velocity to bigger value, and only in the end the quarter-wave segment limit realize that its certain some stress concentration that causes can be unfavorable to the function and the service life of device.This utility model is included in the last quarter-wave segment limit of wavelength, the horn of using compound loudspeaker to form, or the horn that is combined to form of traditional loudspeaker, or in combination, use single loudspeaker etc. at double.Utilize the maximization of ε (x) curve from 0 to 1/4 λ scope integral domain, guarantee that simultaneously the pressure ε (x) of any point is no more than the stress value of correspondence infinite life, make when vibration velocity gets a promotion and the stress of every bit all below the S-N of material curve.The material that uses in this utility model can be titanium or titanium alloy, aluminum and aluminium alloy, rustless steel or pottery etc.This ultrasound waveguide resonant frequency at 20kHz between the 100kHz.The sustained stress that this utility model comprises the S-N curve of determining materials used in the ultrasonic amplifying device and uses a plurality of horn single or that compound horn forms to obtain below the S-N curve in Vltrasonic device is come hoisting velocity.

If 1/4 λ length of a horn,stepped and 1/4 λ length combination of a pyramid type horn are become complex horn together, draw its strain curve shown in curve among Fig. 88 by the finite element software simulation, as can be seen from FIG., in 1/4 last λ scope, stress maintains high level but still under the S-N curve, this structure is than the stepped ultrasonic transformer long service life of uiform section ratio, conical horn amplification than the uiform section ratio is big, under the prerequisite in service life of assurance device, make vibration velocity amplification optimization.

The related complex horn structure of this utility model as shown in Figure 7.Its front end is one section axle construction 31, thereafter structure is the horn structure 32 of one section cross section gradual change, this part can be an arc transition, also can be straight line or other curve transition, it then is the combination 33 of the loudspeaker of shapes such as ladder, circular cone, it can be single horn body, also can be the combination of identical or different horn body, is decided according to the actual requirements.

The above-mentioned description to embodiment is can understand and use this utility model for ease of those skilled in the art.The person skilled in the art obviously can easily make various modifications to these embodiment, and needn't pass through performing creative labour being applied in the General Principle of this explanation among other embodiment.Therefore, this utility model is not limited to the foregoing description, and those skilled in the art should be within protection domain of the present utility model for improvement and modification that this utility model is made according to announcement of the present utility model.

Claims (8)

1, a kind of medical supersonic amplifying device, it comprises horn, end effector, horn is connected with end effector, it is characterized in that: this horn is made of axle construction and/or one or more horn bodies, the horn body longitudinal section is pressed the mathematical function rule and is changed, and this function is notch cuttype, exponential type, pyramid type, Bezier type, Gaussian curve type or suspension cable shaped form.

2, medical supersonic amplifying device as claimed in claim 1 is characterized in that: its head shaft structure front end is connected with transducer mount, and the rear end is connected with the horn body of longitudinal section gradual change, and this horn body links to each other with end effector.

3, medical supersonic amplifying device as claimed in claim 1 is characterized in that: 1/4 wavelength when length of this axle construction and horn body is operating frequency or the odd-multiple of 1/4 wavelength.

4, medical supersonic amplifying device as claimed in claim 1 is characterized in that: this horn body near the cross-sectional area of head shaft structure one end greater than cross-sectional area near the other end of tail end.

5, medical supersonic amplifying device as claimed in claim 1 is characterized in that: the cross section of this horn is circle, square or rectangle.

6, medical supersonic amplifying device as claimed in claim 1 is characterized in that: the geometry of this horn body is notch cuttype, exponential type, pyramid type, suspension cable shaped form, Gaussian curve type and Bezier type.

7, medical supersonic amplifying device as claimed in claim 1 is characterized in that: the employed material of this horn is titanium or titanium alloy, aluminum and aluminium alloy, rustless steel or pottery.

8, medical supersonic amplifying device as claimed in claim 1 is characterized in that: its employed ultrasound waveguide resonant frequency is 20kHz～100kHz.

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