CN1850008A - Piezoelectric supersonic micro-cutting method - Google Patents

Abstract

The present invention belongs to a cutting and separation method of biological tissue slice in biomedicine field, and relates to a piezoelectric ultrasonic microcutting method. Said method includes the following steps: making tip end of microcutting tool whose rear end is fixed on the micromotion mechanical platform be close to biological tissue; making the microcutting tool into biological tissue; utilizing the micromotion mechanical platform to drive microcutting tool and making the microcutting tool implement horizontal feeding movement so as to cut and separate out the biological tissue slice by utilizing its ultrasonic vibration.

Description

Piezoelectric supersonic micro-cutting method

Technical field

The invention belongs to cutting, the separation method of biological tissue section in the biomedicine.

Background technology

Along with the develop rapidly of biotechnology and related science technology thereof, the research of biology microscope operating technology is subjected to the extensive concern of Chinese scholars, and the research that wherein relevant micro-cutting cuts operation especially becomes focus.For example, along with the raising of biological engineering and medical research level, biomedical having developed into from molecular level explored the pathogeny of disease and the stage of disclosing biosis essence.The microscopic analysis of pathological section is one of efficient ways, also is means more accurately.But analyze pathomechanism or analyzing gene arranging situation, must from section, propose specified cell tissue zone.So in molecular pathology research, how choosing and collect required research material also is a difficult problem that more often runs into.Generally adopt at present manual cutting, the separation of finishing tissue slice, cause that working strength is big, operator's fatiguability, personal error be inevitable.Therefore, research is suitable for micro OS, can carry out tissue slice is cut and separates, and little to its damage, makes the micro manipulator tool of its convenient and suitable successor operation, and is significant.

Summary of the invention

The purpose of this invention is to provide a kind of piezoelectric supersonic micro-cutting method, with overcome the manual cutting of finishing tissue slice, separate cause that working strength is big, operator's fatiguability, defective that error is big.It is finished by following step: one, make the tip that the micro-cutting cutter tool 2 on the fine motion mechanical platform 1 is fixed in the rear end press close to the surface of biological tissue 3, the angled θ of upper surface of micro-cutting cutter tool 2 and biological tissue 3, fine motion mechanical platform 1 is for having the micromotion platform of three the coordinate direction freedoms of motion in space; Two, make micro-cutting cutter tool 2 incision biological tissues 3; Three, make micro-cutting cutter tool 2 under the driving of fine motion mechanical platform 1, feed motion in horizontal plane, thus cutting and separating goes out biological tissue section, and in the process of feed motion, micro-cutting cutter tool 2 carries out supersonic vibration along himself length direction all the time.When the present invention cuts, micro-cutting cutter tool drives lower edge predetermined cuts orbiting motion at high-precision fine motion mechanical platform 1, simultaneously, micro-cutting cutter tool is constantly done supersonic vibration, under ultransonic effect, it is easier to cut, and the edge of biological tissue section is more level and smooth, cutting back tissue can directly carry out next step analysis, does not need subsequent treatment.Thereby overcome that hand cut, separating bio tissue slice working strength are big, operator's fatiguability, defective that error is big.The present invention introduces the microoperation field with the ultrasonic cut principle, based on the micro-vibration incision principle of piezoelectric supersonic, adopts the supersonic vibration principle to carry out the development of microdissection instrument, has opened new thinking for micro-cutting cuts Study on Technology with development.Thereby promote the development of microdissection technology, promote the progress of biotechnology research.

Description of drawings

Fig. 1 is an operation chart of the present invention, Fig. 2 is the biological tissue section design sketch of microdissection by hand, Fig. 3 is with 2 actions of fine motion mechanical platform 1 control micro-cutting cutter tool, but the cutting artifact tissue slice design sketch that does not have supersonic vibration, Fig. 4 is with the inventive method straight path cutting artifact tissue slice design sketch, and Fig. 5 is with the inventive method circular trace cutting artifact tissue slice design sketch.

The specific embodiment

The specific embodiment one: specify present embodiment below in conjunction with Fig. 1 to Fig. 5.Present embodiment is finished by following step: one, make the tip that the micro-cutting cutter tool 2 on the fine motion mechanical platform 1 is fixed in the rear end press close to the surface of biological tissue 3, the angled θ of upper surface of micro-cutting cutter tool 2 and biological tissue 3, fine motion mechanical platform 1 is for having the micromotion platform of three the coordinate direction freedoms of motion in space; Two, make micro-cutting cutter tool 2 incision biological tissues 3, the degree of depth of incision is 3～6 microns; Three, make micro-cutting cutter tool 2 under the driving of fine motion mechanical platform 1, first traverse feed length feed again in horizontal plane, the traverse feed again of perhaps first length feed, thereby cutting and separating goes out biological tissue section, in the process of traverse feed and length feed, micro-cutting cutter tool 2 carries out supersonic vibration along himself length direction all the time, and the frequency of vibration is 40～50 KHz.

Cutting tool is along the oscillation trajectory of tool axis as shown in Figure 1:

S(t)＝Acos(2πft) (1)

A in the formula-vibration displacement amplitude; F-frequency of vibration

Cutter movement locus with respect to material to be cut matter in the x-y coordinate plane is so:

x(t)＝Acos(2πft)cosθ+vt (2)

y(t)＝Acos(2πft)sinθ (3)

θ in the formula---cutting tool and horizontal plane inclination angle;

V---cutter is pressed cutting track traverse feed speed cutting speed

The speed of cutter in the x-y coordinate plane is so:

v _x(t)＝v-A2πfsin(2πft)cosθ (4)

v _y(t)＝-A2πfsin(2πft)sinθ (5)

Work as A2cv, i.e. v _XminIn the time of＞0, cutting tool not be cut material and separate with smear metal, cutting at this time is called the vibration cutting that does not separate state; As A2 π f＞v, i.e. v _XminIn the time of＜0, cutting tool be cut material and separate with smear metal, cutting at this time is called the vibration cutting of released state.

General frequency is higher when cutting for supersonic vibration, is operated in the vibration cut state of released state.The cutter of this state can be expressed as with respect to the cutting speed that is cut material:

$v_{\mathrm{xx}}\left(t\right)=\left\{\begin{array}{cc}v-A2\mathrm{\π}f\sin \left(2\mathrm{\πft}\right)\cos \mathrm{\θ}& (t_b+\mathrm{nT})\≤t\≤(t_e+\mathrm{nT})\\ 0& (t_e+\mathrm{nT})\≤t\≤(t_b+(n+1)T)\end{array}\right.---\left(6\right)$

$v_{\mathrm{yx}}\left(t\right)=\left\{\begin{array}{cc}-A2\mathrm{\π}f\sin \left(2\mathrm{\πft}\right)\sin \mathrm{\θ}& (t_b+\mathrm{nT})\≤t\≤(t_e+\mathrm{nT})\\ 0& (t_e+\mathrm{nT})\≤t\≤(t_b+(n+1)T)\end{array}\right.---\left(7\right)$

T-vibration period in the formula; t _bThe time of cutting beginning in-each circulation; t _eThe time that cutting finishes in-each circulation; N-0,1,2

As seen the supersonic vibration cutting process is discontinuous.It also is discontinuous that cutting force in the cutting process changes.Suppose to advance the degree of depth u of cutting force direct ratio and cutting ₀With width b ₀The average cutting force F that advances _EveIn the process of ultrasonic cut, can be expressed as follows:

F _eve(t)＝K _eveb ₀u ₀h(t) (8)

K in the formula _EveThe resistance coefficient of-direction of propulsion; H (t)-unit boxcar, the expression cut state

$h\left(t\right)=\left\{\begin{array}{cc}1& (t_b+\mathrm{nT})\≤t\≤(t_i+\mathrm{nT})\\ -1& (t_i+\mathrm{nT})\≤t\≤(t_e+\mathrm{nT})\\ 0& (t_e+\mathrm{nT})\≤t(t_b+(n+1)T\end{array}\right.---\left(9\right)$

When h (t) was 1, the facet of cutter and the frictional force direction between the smear metal were consistent with general frictional force direction; When h (t) was-1, expression frictional force direction was reverse; When h (t)=0 the time, the expression cutter be cut material and separate with smear metal.As seen, in the process of supersonic vibration cutting, cutting process is discontinuous, and discontinuous ultrasonic cut effect has effectively reduced the propelling cutting resistance of cutter, thereby average friction power also reduces significantly, help reducing in the cutting process owing to the heat that produces of friction.Therefore, the supersonic vibration cutting makes the cut edge more smooth, corrugationless, and influence reduces to the cutting ambient substance.

The specific embodiment two: specify present embodiment below in conjunction with Fig. 1.The difference of present embodiment and embodiment one is: the tip of micro-cutting cutter tool 2 is a needle-like, adopts the supersonic vibration driver part of piezoelectric ceramics 5 as micro-cutting cutter tool 2.The driving of supersonic vibration can be realized it is carried out in the rear end that piezoelectric ceramics 5 is fixed on micro-cutting cutter tool 2.So be provided with, simple in structure, cost is low, the engineering reliability height.

Claims (2)

1, piezoelectric supersonic micro-cutting method, it is characterized in that it finishes by following step: one, make tip that the micro-cutting cutter tool (2) on the fine motion mechanical platform (1) is fixed in the rear end press close to the surface of biological tissue (3), the upper surface angled (θ) of micro-cutting cutter tool (2) and biological tissue (3), fine motion mechanical platform (1) is for having the micromotion platform of three the coordinate direction freedoms of motion in space; Two, make micro-cutting cutter tool (2) incision biological tissue (3); Three, make micro-cutting cutter tool (2) under the driving of fine motion mechanical platform (1), feed motion in horizontal plane, thereby cutting and separating goes out biological tissue section, and in the process of feed motion, micro-cutting cutter tool (2) carries out supersonic vibration along himself length direction all the time.

2, piezoelectric supersonic micro-cutting method according to claim 1, the tip that it is characterized in that micro-cutting cutter tool (2) is a needle-like, adopts the supersonic vibration driver part of piezoelectric ceramics (5) as micro-cutting cutter tool (2).

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