CA2143487A1 - High-intensity ultrasound therapy method and apparatus with controlled cavitation effect and reduced side lobes - Google Patents
High-intensity ultrasound therapy method and apparatus with controlled cavitation effect and reduced side lobesInfo
- Publication number
- CA2143487A1 CA2143487A1 CA002143487A CA2143487A CA2143487A1 CA 2143487 A1 CA2143487 A1 CA 2143487A1 CA 002143487 A CA002143487 A CA 002143487A CA 2143487 A CA2143487 A CA 2143487A CA 2143487 A1 CA2143487 A1 CA 2143487A1
- Authority
- CA
- Canada
- Prior art keywords
- random
- signal
- electronic signal
- wideband
- pseudo
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N7/00—Ultrasound therapy
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F7/00—Heating or cooling appliances for medical or therapeutic treatment of the human body
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/0207—Driving circuits
- B06B1/0223—Driving circuits for generating signals continuous in time
- B06B1/023—Driving circuits for generating signals continuous in time and stepped in amplitude, e.g. square wave, 2-level signal
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/22—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
- A61B17/22004—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves
- A61B2017/22005—Effects, e.g. on tissue
- A61B2017/22007—Cavitation or pseudocavitation, i.e. creation of gas bubbles generating a secondary shock wave when collapsing
- A61B2017/22009—Cavitation or pseudocavitation, i.e. creation of gas bubbles generating a secondary shock wave when collapsing reduced or prevented
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
- B06B2201/70—Specific application
- B06B2201/76—Medical, dental
Abstract
ABSTRACT OF THE DISCLOSURE
In a high-energy ultrasound therapy method and apparatus, said apparatus comprises a therapy device with at least one ultrasound therapy transducer element and a signal generator supplying an electronic signal to said ultrasound transducer element, the signal generator supplying the transducer(s) with a wideband electronic signal of the random or pseudo-random type.
In a high-energy ultrasound therapy method and apparatus, said apparatus comprises a therapy device with at least one ultrasound therapy transducer element and a signal generator supplying an electronic signal to said ultrasound transducer element, the signal generator supplying the transducer(s) with a wideband electronic signal of the random or pseudo-random type.
Description
21~3487 !
EIIG~ N91:TY ~TRA91;~UMD l~PY J~ETEOD AND l~PAR~TIJS
W~ I CO~!R9I.~13D CieLVITA~IO~ ~:~J~5:CT AND REDIJCl~ SID~: I.OBE8 . ",.. .....
5T~e p~e~ent inventio~ rela~es to a th~rap~ method and apparatus ~or ~enerating high-int~n~lty ultra~ound with control of cavitation e~e~t, and to the u~e ~f thl8 method and apparatu~ for reducing ~econdary lobea ~et up by a periodic-type ~tructure.
10It is k~ow~ ~hat ultra~ound ~he~apy, u~in~ a : piezoelectric transducer driv~n b~ sin~wav~-typ~
~ el~ctronic signal~ m~k~s it pos~i~le to create tl~sue :: le~ion~ through tisau~ hoating du~ to ultrasound ahsorption. Fur~he~m~re, ~u~h ti88U~ le ion~ c~ be~
limited to a ~peci~io ~olume by ~arry~ng out thorapy u~ing fo~used ultr~ound, which i8 par~lcula~ly valuable ~or achieving ~ff~ctive t~e~tme~t in cancer therapy ~uch a~, for examplo, canc~r o~ the pro~tat~, bre~st, ~rain, et~.
20Bxi~ing ~yp~rthermia apparatus ~Bin~ ultr~ound heat~ tumor~ to a moderate temp~rature o~ the order ~f 42.5C ~or a tim~ of the o~der of one h~ur.
Sinc~ hy~erth~rmia trcatment may be ln~ufflci~nt, lt can he~ ad~anta~eou~ ta att~pt to obtain much highsr t~mpera~ures, ~or exa~le of around 80C, with a view to ~en~lti~lng cell~ or completely d~troying them. To ~chie~ thi~, lt i~ nece~sary to ~upply acou~tic en~rgy to the ti#~Ue ovor a bri~ period, ~enerally o~ the ord~r - o~ a fe~ ~acond3, in~ orde~, notably, to avoid h~at loss ~y natural tr~ns~er, notably due to blond circulation, throughout ~he ti~su~. Sufficient n~rgy needs ~o be ~ d ' !'i I ~ ~ and thi~ i,mplia~ u~ing hl~h ultrasound in~ensity.
Thi~ how~v~r bringo one up against th~ tachnical problem~ re~ulting :~rom czlvi'cation p~enomena which b~come 3S even mor~ acc~ntuat~d a~ acou~tic int~nsi~y increa~e~, h~ b~e~ de~crib~d i~ de~all ~y ~. Hynyne~ in " The ; : .
threshold for thermally ~i~n~icAnt ca~i~a~ion ln dog~
C001~ ~S~ cr o~ cz L~ I SS~, 9Z:IT sa.
EIIG~ N91:TY ~TRA91;~UMD l~PY J~ETEOD AND l~PAR~TIJS
W~ I CO~!R9I.~13D CieLVITA~IO~ ~:~J~5:CT AND REDIJCl~ SID~: I.OBE8 . ",.. .....
5T~e p~e~ent inventio~ rela~es to a th~rap~ method and apparatus ~or ~enerating high-int~n~lty ultra~ound with control of cavitation e~e~t, and to the u~e ~f thl8 method and apparatu~ for reducing ~econdary lobea ~et up by a periodic-type ~tructure.
10It is k~ow~ ~hat ultra~ound ~he~apy, u~in~ a : piezoelectric transducer driv~n b~ sin~wav~-typ~
~ el~ctronic signal~ m~k~s it pos~i~le to create tl~sue :: le~ion~ through tisau~ hoating du~ to ultrasound ahsorption. Fur~he~m~re, ~u~h ti88U~ le ion~ c~ be~
limited to a ~peci~io ~olume by ~arry~ng out thorapy u~ing fo~used ultr~ound, which i8 par~lcula~ly valuable ~or achieving ~ff~ctive t~e~tme~t in cancer therapy ~uch a~, for examplo, canc~r o~ the pro~tat~, bre~st, ~rain, et~.
20Bxi~ing ~yp~rthermia apparatus ~Bin~ ultr~ound heat~ tumor~ to a moderate temp~rature o~ the order ~f 42.5C ~or a tim~ of the o~der of one h~ur.
Sinc~ hy~erth~rmia trcatment may be ln~ufflci~nt, lt can he~ ad~anta~eou~ ta att~pt to obtain much highsr t~mpera~ures, ~or exa~le of around 80C, with a view to ~en~lti~lng cell~ or completely d~troying them. To ~chie~ thi~, lt i~ nece~sary to ~upply acou~tic en~rgy to the ti#~Ue ovor a bri~ period, ~enerally o~ the ord~r - o~ a fe~ ~acond3, in~ orde~, notably, to avoid h~at loss ~y natural tr~ns~er, notably due to blond circulation, throughout ~he ti~su~. Sufficient n~rgy needs ~o be ~ d ' !'i I ~ ~ and thi~ i,mplia~ u~ing hl~h ultrasound in~ensity.
Thi~ how~v~r bringo one up against th~ tachnical problem~ re~ulting :~rom czlvi'cation p~enomena which b~come 3S even mor~ acc~ntuat~d a~ acou~tic int~nsi~y increa~e~, h~ b~e~ de~crib~d i~ de~all ~y ~. Hynyne~ in " The ; : .
threshold for thermally ~i~n~icAnt ca~i~a~ion ln dog~
C001~ ~S~ cr o~ cz L~ I SS~, 9Z:IT sa.
2~3487 ` ..
thigh muscle in ~ivo" publish~d in Ultra~ound In Medlcine and Biology, vol. 17, No.~, p~ge~ 157-171, (1991).
Acou~tic ca~it~tion co~er~ any.phy~ical phenomena i~-vol~lng ~h~ activity o~ bubble~ o~ micro-bubbles o~ ~as und~rgoing mo~emen~ as a re~ul~ o an acou~tic ~leld.
Tw~ typa8 C~ cavltat~on can generally be dl~ting-ui~hed:
- st~ble ca~it~tion where ~he walls of the b~bble~
are os~illating at the ~requency of the ultra~ound ~ield without too great a conse~uence ~or the surrounding c~ , but which con~id~rably di~turbs ultra~ound transmi~ion by reflecting or ~aatt~rlng incldant wave~.
Thi~ phenom~non can appear ~t ~ery ~ow ~e~ure lev~l~ a~
300n aa bubble3 ar~ pre~e~t in th~ medium;
~ transitory cavit~tlon where bubble~ e~pand up eo their re#onant ~ize, and than implode viol~ntly. In this ca~o, tha ~n~r~y accumulated by the bubble3 i~ ~imul-ta~eou~ly r~laa~d in the form o~ a shock wa~e, with inten~e heat (generally from 1 ooO ~o 20 000K) and microj~t~ that can ~each ~pee~ o~ loo m/q. All thi~
laad~ to th~ creation o~ ~ree radicals and mechanical de~truQtlon of ~urrounding ~ ue. Generally, this phonomenon a~pe~r~ st~rting ~rom high incident pres~ures which thu~`defi~e~ the cavitation thr~hold~
Every living medium contains ~ ~ertain amount.of di~
~ol~ed gas present in tha form of h~bbl~ mlcronuclai Uhd~r th~ e~ect of an ultr3sound ~ield, the ~ucle~
axpand thr~u~h ~ phy~ic~l phenomenon know~ a~ ~ecti~ied diffuc~on to rea~h ~ cr4tical ~iz~ known ~a th~ ~laka ~hr~shold.
The inventor show~d a while ag~ ln an ar~cle . ientltled ~'Effect_ of cavita~ion in high i~ten~ity therap~utic ultrasound" publi~hed o~ pa~eq 1357 to 13~0 of volum~ 2 (l991) of "Ultra~onic~ Sympo~ium Proc~ding~"
~published by ~.R. ~cAvoy) that thc us~ o~ intensiti~s that were too~ high, gen~rally abo~ 3 000 W~cm2 reduced the therapeu~ic effects of thermal tre~tment involving tis6ue de~tructlon. Thi~ phenomenon can be ~xplain~d by 1~00[21 H~SYI~ Z L~ 1 C~12, 9Z ~ .
' "' ~
~ 2~3~7 ~upposing that at the~ inten3i~ie~, cavitatlon bub~las which may a~ear ahead o~ the ~ocal Ypot ~ct ~ a screen f - .
for in~ident ultr~ou~d wa~e~. Mor~ov~r, with th~
8p~0i~iC aim o~ reducin~ cavitatio~ cffect~, F.J. Fry~
5 stated ln Inter~at~on~l Patent a~llcation Wo-A-8~/0790~ -that it i~ nece~æary to inhibit produation of micro-bubble~ in th~ primary ~ocal ~i~e to a~oid le~ion~
appea~ing out3ide said ~ite (~e~ pa~e 15 of ~aid PAtent application). Under ~hese conditlon~, lt iR ~tated that - :
~e lnten~ity ~hould not exceed 300 w/cm~ at a 1 MHz fraque~cy, o~ Z,10~ WJ~m2 at 4 MHz.
K. ~ynynen al90 ~howed in the above-cited articl~
that an intensity of 700 ~/cm2/MHz ahould ~e con~idered ~b as a ~aximum valu~ ta be u~ed in hyp~rthenmi~ treatment ~, at high~r lev~ vl~ation leads to unpr~dictable ener~y ab60rption.
To ~um up th~ ~tat~ of ~h~ art, cavitation hind~r~
penetration o~ aaousti¢ wave~ into tissue thu~ pre~entlng :~ :
treatme~t fro~ following pred~ctabla lin~s~ Moreov~r, 20 ~a~ltation can lead to uncontroll~d ti~ue de~truction, ~.
outslde the target ~olume. It is thu~ appropriate, ..
regardles~ o~ the applieation envisaged ~in oth~r word~
thermal tre~tm~nt at high tempexature for tis~u~ de- ~:
~truction, ar at mo.d~r~t~ ta~aperature or hyperth~3rm~a), ~ - .
: ~ to increase cavitation onoet thre~hold~
To avoid cavl~ation, the only recomm~ndation~ that can be f ourld in the p3~ior art consist eith~ ln reducirlg ~`~
acou~tic lnten~lty, or em~ ttlng in a di~con~cinuous ~ann~x, u~ing ~a~e trai~ of de~ermined duratlon, and.
30 respectin~ A waiting ti~e betwe~n th~ tr~in~, or, yet a~ain, increa6ing ~mis~ion ~requency.
However, rqducing a~oustic iate~ity or u~ing di~con- ;
tinuous emi~ion lead~ to a los~ o~ ac~ustic ener~y ~.
tran~mitted t~ the medium, which llmi~a temporatur~ rise 35 or increa~a tr~a~ment duration. Furthermore, in~reasing ~.
em~sion freguency limlts the depth o~. treat~e~t~
absorption by ti~ue being directly proportlo~al to ~requenc~, a~ d~s~ribed by Daniel3 et al., in the journ~l sno~~S~ Cl 8~ CZ L~ I 6~ ~Z:II S~. Zo~bZ ;
,'':'~
~`:` 21~3~87 :
"Ultrasound in Medicine and Blology" ~rol . 13, No. 9, ~19~7) in th~ articl~ ~ntitled "Ultra~onically induced ga~ bubble~ producti~ in ag~r bas~d gel~n. I~ ~hould ~lso be noted th~t, in th~ prior art, continuou~
sinewav~s are ~mployed ~or ti~u~ heating, and thu~
emis~ion du~atio~ i~ far higher than ~ignal period.
U~ually, in~onification of ti~ue ~or ~e~eral ~econ~ at a fres[uency c:omprlsed between 1 and 5 MHz l~ envisaged.
Certain authors h~re, on the other hand, consid~red 10 u61ng acou~tlc waves o~ a pul~ed typ~s, with a duration of the order of se~rer~l perio~, in other word~ ~veral rnlcrosecond~;, but for a complet~ly dif ~erent pu~pose, ~pec:i~ically eith~r the c~e~truction o~ concretlon~
~li tho~rl~t~tlc~n), or for diagnc~ (DQPP1er ultra~;ound : . .
~canning).
The ca~itation phenomena produced by such pul~es have bee~ ~tudied. For example, ~owlh!~ and Crum in an articl~ entitled " Cavitation thre~hold measurementa ~or microsecond langth pu~ 8 of ultrasound~ publi~hed i~ J.
20 Acou~tic 90c. A~. 83 ~ un~ 1988, inv~a~tigat~s th~
evolution o~ c~itatlon thrc~hol~ as a ~unctiQn o~ pu180 ,' widt~ and pul~e fr~qu~ncy. ~imilarly, Deliu8, while studying ~a~ltation pr~duced by lithotripter~ reaommended ~educing acou~tic wav~ repctition ra~e~ (see "~f~ects of lithotripter ~hoak wave~ on ti~u~ and mat~rial~
Frontier3 on non-lin~ar acoustic~, ~dited by M.F. ~amil- ~;
ton and D.T. ~ k~tock, Ele~vlor Scienc~ Publishers, London lg90).
How~er,. puLae ~thods. do not make it po~siblo to ` ~::
produco ~ temper~tu~e rl~e in tis~uo since e~ch pul~e o~ly tr~nsports small amount of cner~y, and the pulses n~ed to be spaced. It i~ thu~ not possible to asslmilate work don~ with the~e wave~ with thq work at the basis of thi~ pre~ent in~ntion.
T~u~r the. prl~ciple aim o~ th~ prc~ent invention is ;~
to resolve the new tochnical problom of pro~i~ing a ~olution enablln~ maximum energy to be supplied to the ~00~1 EI~S~ ST ~ CZ L~ I CC~ Z:TI S~. ZO~Z
'','. ' ~'.'' ' : '.,:' ,`';, , -:: :: : ~: ,:
21~3~87 . . .
medium, pref~rably ~he ti~ue o~ a livln~ ~ing, in ;~
particular an a~imal or huma~ being, ln the ~hortest possibl~ time and p~ef erD~ly reducing or preventing the oc~urr~nce o~ ea~itation ~henome~a .
A further aim ~ the in~ention i~ to re301ve the n~w t~chni~al p~o~lem o~ providlng a solution enabling maximum ~rgy to be ~upplled to th~ m~ium, pr~arably ~he tia~ue of ~ li~ing baing, in par~icular an animal or huma~ bei~g, in the ~horte~t possible time, whil~
simult~ously enæuring ~a~e a~d ef~ec~ive control Of heat de~o~it, thu~ making lt po~ le eithsr to provi~e mod~rat~ ther~al ~reatm~nt in ~he ~ramewor~ of hyper-thexmla, or to carry out thermal tr~atmont at high tcmpcrature~ tQ achi~Ye tis~u~ de~tructiQn, pre~era~ly . .;~
15 reducing or llmiting ca~ita~ion phenomen~. -- .-~
Moreo~er, the in~ention r~sol~es th~ ~ew p~oblem of 3ec~ndary focusing whieh can occur wben perlodic ~r ~-`
qu~ai-periodic ~tructures are pre~ent on the path betw~Qn the emi~sion de~ice and the re~ion to be treated. ::
~0 The preæent inv~ntibn h~s the ~urther aim o :~
re~olvlng th~ abo~e technical probl~mg in ~ ~imple, r~liabl_, inexpen~lve mann~r makin~ widespread indu6trial ~nd madical uae ~os~lble. : :.:
The pre~ent invention provides a ~tl~iactory ~5 901ut~0n ~or th~ firs~ time to the technic~l problems ~.
defin~d abo~e, and has ~urth~ir tcchnical Advantagee which ~ ::
wlll hecome more clear ~rom tho det~iled de~cription which ~ollow~, including the attach~d drawing~ which con~tttute an integral p~rt thereo~. :
Thu~, ~cc~rding to a flrst as~ect ~ there i~ provided a method ~0~ ~enerat~ng ultrasound waves i~ a ~opagation !` mediu~ comp~i~ln~ acti~ating at least one ul~ra~ound ~ransducer ~lement by an elec~ronic signal ~upplied by a ::
sign~l generator and xedu~l~g or pre~enting c~Yltation :
35 ph~nomon~ re~ulting from ths propaga~ion of ultra~ound ::
wave~ emi:tted by the ul~rasound tranedu~ier element wlthin.
the pxopa~a~ion m~dium by the u~e of a siynal ~n~r~to~
supplying a wid~band elect~onlc signa~
L00~ H~S~IH ~ CT or ~Z L~ T S6~ LZ:TI 9fl, zo~z 2~3~87 ~i , ! .
rn thi~ tnvention~ in oth~r words in the de~cription and claim~, ths oxpre~ion "wideband" ~or th~ epectrum o~
an eLectronic ~ign~l m~an~ that ~ignal sp~ctrum bandwidth i~ a~out 50~ of ~he central fr~-quoncy. For ~xnmpl~, for a ~ignal of central frequenc~ 2 M~z, bandwidth will b~
around 1 M~ and will thu~ co~r ~requensieY ~a~y~ rom abou~ 1. 5 MH3 to about 2.5 M~z.
I~ ~ pref~rred em~odlment, a ~ignal generator ~:.
supplying a continuou~ rand~m or ~eudo-random electronic ~ignal i~ em~loyed.
Throughout this speci~catio~, the term ~con~inuous"
should be tak~n to msan that th~ duratlon of emlsslon o~
the ~ignal i~ ~ery much long~r than t~ period of the slgn~l, a~ ha~ al~ead~ been sald in the introductlon 15 abov~. ~
Acco~ding to on~ preferred feature, the a~ovesaid .~:;
ignal gen~rator s~upplies a p~e:udo-ra2~dom electronic ~i~nal o~ th~ Gau~sian or Poi~onian d~tributio~ t~pe.
Su~h ~ignal can t~ l~ally be obtained fro~ a sourc~ a ~.
20thormal noi~e ampllfi~3d by e~le~ronic ampllfication. .~
According to a further advantageous ~eature, the ~aid .:~ .. o ~igne.l t3en~3rator ~upplie~ a l?oeudo random electronic c~ignal using G~lay coding. ~ -~ccording ~t~:a ~u~er ad~antagOEtaus fe~ture, the 6aid ZS~i~rnal g~nerator ~upplieY a }~eudo-random el~ctronic si~n~l using Barktr coding.
Ac~ os:din~ to still a ~urthex ~dvantagtaou~ ft3ature of thti~ in~r~ntlon~ ~he E3aid signAl generator ~u~pli~ a c:oded el.qctronic ~ sign~l o~ M-s~t~ut3nce pseudo-randc~m type .
30M-~e~ena~ signal~ also referred to ac maximum l~ngth - :: -binary acquence~ are of th~ typ~ de~ribed b~ Jeasl-Y~e~
Chapelon in Chapter 6, on pag~ 225 to 23~, partlcularly .
page 230 onwards of the ~oc~k "Progr~:ss in medic~
imaging" edit~d by Profeasor Newhou~e arld pu~ hed by .
3SSpring~r Vexlag, New Yorlc, 1988 whlch i3 incorporated ~ * :~
her~i~ by. ~e~renc~
Such M-~equ~n~ or ~olay or Bark(3r pl3~udo-random ~ .
cod~d signal~ can be employed directly or can pha3e- or 800~ H~S~IH ~ Sl ~ SZ ~ I SS~3 LZ:~T g~, ZOi~Z .'~
7 `~
frequency-modula'ce an electronic eignal thc carrier f requ~ncy of whlch correspond~ eo the tr~n~ducer ' nominal- op~r~:n~ Sr~uen~.
Coded signals of the M-3equence p~eudo-random type 5 are pa~icularly pre~erred. Such slgnalE~ are prf3c~ sely de~cribed in ~Progre~ med~e~ glngn. ~riep~
they co~i~t of b.inary 8ignal~ buil~ up by p~oudo-random repetitio~ of J?ul~^~ of elem~ntary duration E:Ach of said sequ~nc~ss is xe~p~ated with a ;repetition p~riod T
lO 'chat i8 chara~terl~tic of the M ~equonce.
A more~ pr~ci~ deacription of an M s~quonc~ ~ignal c~n be pro~ided with referenc~ to FIG. 4 attached, ~ ~
- element~ry pulse duration 11011 O.l ~L9 C: u ~ 100 ~3, '.
ideally akou~ ~ fL3, - re~p~ti~ion period T: 1 ~9 c T c l~ ~, ideally com-prl~ed b~ws~n ~.5 and 5 ~
The p~eudo-ra~dom typ~ cod~d signal~, parti~ularly the currently pre~erred M ~equenc~ p~eudo-rando~ type sllgnals can readily be obtained usin~ el~c:tx~onie circuita zo well lcnown to tho~ ~killsd in th~ art.
Th~ u~ o~ l3uch wideband electronic E;i~als, ~ ~
pref~rably random or p~eudo-random, mak~s it pos~ibls to :: :
ac~iav~ b~tter c~ntrol o~ heat depo~ition and to a~oid tempe~atu~e. inc~ease di~turbancc by ~econdary e~e~t~
25 such as ca~lt~ion, ~hu~ e~abling spontaneous tissue ::
dsstruction to ~e a~olded part~cularly in the ~aee o~
~oder~t.~ he~tlng used ln hyperthe~mla..
9ooondly, conaidering hlgh-intensity u~, the invention ~k~ . po~ible/ to employ high~r intensiti~s :
3nd to redu~, for a given ultrasound dose, firing duration and, con6equently, the dur~tion of creatment, whils a~oi~ing cavltation phenomena ~hus m~king iC
po~ible to carry out treat~ent of tumore in living b~ing3, in particular animals or human beings, ~ith ~5 higher l~vel o~ ~a~ety whil~ reducing the risk o~ damage at ~ari~us.in~r~e~:.
From a ~econd a~pect, the present in~cntion also pro-vides a therap~ apparatu~ comprising an ac~ual therapy 600 SHIH ~ ) Sl ~ CZ L~ T CC~ 8Z:IT S6. Z0~2 2~3~87 device eo~prising at lea~t on~ ultra~ound therapy tran~duecr Ql~nt and ~ ~ignal ~cner~tor ~upplylng an ~lectro~ic signal to said u}tra~ound tran~ducex elem~nt, in whieh the ~i~nal g~neratDr ~upplies a wideband ~lectro~ic ~lgnal o~ th~ random or pseudo-r~ndom typo.
ln on~ pr~ferred embodiment, the ~ignal ~enerator . ::
.supplie~ a ~aua~lan or Poi8~0nlan di~tri~ution type random ~ignal. ::
~n another pre~erred embodim~nt, the ~ignal generator supplie~ a ~olay coded or a Barker Goded pseu~o-~andom ~ignal. ~;
In ~nother pre~err~d embodiment, the ~ignal ~e~erator ~upplie~ ~n M-sequ~nce paeudo-random type coded :~
elec~rontc si$~al................................................... , -~ Thl~ M-s~quence p6eudo-~andom type coded ~lectronic 3~nal p~e~erably has an elementary pul~e d~ration ~e) .
theta comp~i~e~ between 0.1 ~ and 100 ~ and 1~ ld0ally of About 1 ~ nd a period of repet$tion T ao~pri~ed ~etween 1 ~ and 10 ~ and ~deally compri~ed bRtween 0.58 and 5 ~
In eithar a~pect o~ th~ invention, to increase the ef~ectiven~ of ca~it~ effec~ x~duction or preYention, a~ ultraso.und tran~ducer which pre~erably i~ it~el$ ~ ` ?`, w.ideban~, 18' u~d, in o~hc~ words the ultrasound ;:`~
transducer gener~te~ ultra~ound wa~es when excited by a 8~ ~nal th~ reque~cy of w~ich ie qubstantially di~erent ~ro~ its nomlnal ~requQnay.
U~ually, tWo type~ of tran~duc~r can b~ u~ed for gen~
er*ttn~ ~ontinuou~ ultra80und waves ~or. th~rapeutic. ::~
30 purposes. ~he~e comprise, f~r~tly, conv~ntional -~
ult~asoun~ tran~ducors e~se~eially consl~ing o~
piezoelectric ceramia. Such ceramlc~ ha~ an acou~tic impedance whlch i~ v~ry differene ~rom that of the ;~
propagation medlum and, as a re8ul~ o~ ~hi~, ~hei~
35 coupling with ~ald medium i~ poor. Thi~ re~ult~ in .
s.trong.vibration3 ~f the ceramic when it i~ ~xcit~d hy ~n elect~lc ~ig~al, the re~ulting ~ra~ound transduccr ~:
havlng a narrow ~re9uency bandwidth. ~`
OTO~ H~S~ Cl 0~ ~Z L~ T ~C~ qZ:TT S~. ZO~PZ ~ -;
3~87 `;
g I .....
, For ther~py ~arrled out ~o d~te u31~g ul~r~ound waves ~ ouch tran~ducer~ are suitable a~ the control ~ignalg ~r~ ~hemsclve~ of tha ~arrow ba~d ty~e.
In ~he fr~mework o~ this lnv~ntlon, the ~requency band of the ultra~ound tran~ducer~ i~ widened ~y the ap~lic~tlon o~ dif~erent type~ of tr~atment to the ceramic surf~c~, th~se modifying ultra~ound coupliny with the propagAtlon madiu~ Particularly) a layer o~
matexial~ haYing an Acoustic ~mpedance lntermedlate ` `:
betw~en that of ceramic and the propagation m~dium of ap~roprlate thickne~ i8 d~posit~d in this cas~ on th~
ceramic, such a layer being re~rr~d to ~ a quarter-wav~
l~yer. A 30~called backin~ layer c~uld aleo be depo~ited ` :: :
on the back o~ the c~ramic between the latter and the :`
15 air. The~e two ty~e~ of treatment of the ceramic enabl~ :
a wideb~nd ultra~ound transducer to be obt~ined. ::
Another ~ype o~ wideba~d tran8duco~ can b~ obtaiuod ;~
u~ing composite type materials, thi~ being particularly ; ~-suitable for impl~m~ntation in the present invention ~or ao reducing or pr~v~nting ca~itation e~fect~
Thi~ make~ 1~ po~3ibl~ to obtain the de~termining technical ad~ant~ges stated aboYe.
AccordlnS~ to a further ~pect, the invention di~close~ the use, i~: a therapy apparatua comprising at 2 5lcaJt o~e ultrasound trarl~duc~r and .D ~ l gen~rzltor supplyin~ an electro~i~ signal to ~aid tr~n~ducor, of a wid~band ~lectr~nle ~l~nal f~r r~duciny or preventing s2condary fo~uein~ phenomena bqhind ~ perlodic or qu~ per~ Qdic ~;truc:ture~
30Th~ ~or ex~m~le mak~a it po~sibl~ to tre~t the li~er be~l~d the rib cag~i by reducing or prev~nting le~ion~ due ~o seconda~y facu~ing or side lobe phenomena.
In one eimbodlm~nt o~ this third a~ect of the inv~ntion, the wide~and ~l~ctroni~ nal i9 0~ the 35 random or p~eudo-random typo. ::
The ~ideband RlQctronic ~ignal ca~ he a Gauss;~ian or ~ :
Poi~sonian di~trlbutlon typ0 random ~ign~
. .
............. . .... ~ .... .... . ~
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-- 21~3487 ' ' ':
The wideband e~l~ctronic ~i~nal can al~o be a Barker coded ~r Golay cod~d ps~udo-random slgnal.
Fo~ t~e wideband elec~tronic ~ignal, one c~n u~3e a -:
M- se~ue~ce pseudo-random typ~ coded el~ctronic si~nal 5 of a ~r~ue~cy havin~ a~ elementary pul~e du~at ion compri~ed be~twQ~n 0.1 ,us3 and 100 ~ and ideally o~ about :~
3, and ~ p~rlo~l o~ repet~ tion T com~ri~3~3d between 1 and 10 E~ and id~ally comprised between 0.5e and 5 8. : ::;~
The ele~ronic wideband ~3ignal may also ha~e an lo autocorrelation function apl?ro~chlng a Dirac functlon. .
~ urther characte~ri~;tiaæ of the invention will ~ecome cl~3ar rom ~he detail~3d de6cription that i~ollows, including the dra~ing~ which ~onstitut0 an integral part th~r~a. and:th~ cl~im~ ~ccompa~yi~ thia deecription Th~ in~rention will now b~ d~cribed on the basis o~ a : -currently pr~~rred ~mbodlme~t thereo~ slmply by way o~
illu8tr~tlon whlch in no m~nn~r ~hould be con~dered a~
::~: .,:: -: . :::
limiting the scope on the lnvention, with rQ~Qr~nc~ to ;.. ~.--thc attached d~aw~n~s.
FI~ a h~ghly ~chematic r~pr_sentatiqn of a ~:.; :"
known therapy dovic~ for per~ormln~ t~srapy o~ the ti39U~
of ~ llYin~ ~lng, compri~ing a sinyle- or multl-tran~
d~a~r d~ e ha~l~g on~ or ~v~ral piezoelec~ic tran~
25 du~rs, in th~ ~oxm of a 0am~-~ph~rical cup ~llowing :'. :
~eo~etrlcal ~ocusin~ on the proRagation axis Vi9~ bl~ in FI~. 2~ : `
FIG. 2 ~hows a curve in the form of a 6inewa~e a~ a functlon o~ ~ime; t on th~ x-axi~ and.a~plituda A on the y-axl~, according to the prlor art as ~mployed in an ultra~ound wav~ yen~rating device o~ FIG. l; ,~
. i FI~.... 3 i~ a highly ~chcm~tic ~iew of ~ therapy devicq "`~
according to the pres~nt invcntiorl for carryin~ out ;~
th~rapy of li~ing bel~g ti~ue, comprising a wid~band ..
35 elec~ronic ~ignal g~neratlng device, ~aid signal being pr~f~r~bly rand~m ar p~ud~-randcm, delivered to the .
piezoele~tric transducer devlc~ ~or generating an ultraaound wave, the r~ndo~ or pseudo-random ~ignal being ,.:
ZTo~ ~S~IH ~ CT ~t cz L~ I cc~ ~Z:TT 9~. zof~z ~ -:, -. :., ; ~ - ~ : .
~ 21~3~87 .. . ..
11 ' - ' shown diagramma~cally in FIG. 3, ~nd in det~il ln Fr~. 4 ~ a 4~nctlon of ~ime expressc~ in microseconds on the x-axi~, with ~mplitude on thc y-axi~;
FI~. S i~ ~ block di~gram of a ~ctup making it 5 possi~le ~o claarly bring to light reduction in cavita-tio~ by u~lng a random or ~eudo-random ty~e electronic signal for axciting the ultra~ound tran~ducer;
FIG. ~ show~ r~ult~ obtainca with the apparatua in ~IG. 5 ln ~he ~orm of a graph ln whlch the l~ne : :
identiied by the reference 2 corrc~ondo to the random or p~eudo-r~ndo~ ~i~nal accordin~ to the in~ention of FIG~. 3 and 4 joining the points ~how~ by the - o -~ign~, ~nd th~ llne be~ring the re~er~nca 1 re~ul~ ~xom th~ u~ o~ ~ ~inew~v~ ~ig~al according to ~hc prior art :~:
employed in FI~5. 1 and 2, and ~o~in~ the ~olnt~
a~ a ~unc~ion ~ pow~r tran~mltted by the ~ran~duc~r expre~ed in Watt~ on the x-axi~, the valu~ in nano-ampere~ pro~ided by an ammeter inte~ra~ln~ the total amount of light cmit~ed ~y ch~ luMinol ernployed ~eing ~o indi~ated on the y-axiB;
- FI~. 7 ~how~ ~chematically the operation o~ a p~io~
art device in tho pr~senc~ o~ a periodic or quasi-pe~lodi~ atructur~; and - FIa. 8 is a isichematic re~ei~i~tatlon ~imilar to that in FI~. 7 in a d~ice imPlem~n~ins ~he in~ntion.
Wi~h r~fer~n~ to FIQ. 1, th~re i~ i~hown dlagram~ati-cally a known therapy d~vic~ g~n~rially idonti~i~d by re~ere~ce numeral lO, ~or carryir~ out th~rap~ o~ ~he ti~ue o~'ia llving being.
Thi~ tharapy apparatus 10 compriae~ an actual theripy device whlch here takes the form o~ a 3~mispherical cup ~ :~
22 using natural focusing compri~iing one or se~eral piczoeloctric trAnsducer element~, in pii~rticular a :~
singl~ m~nt piezoelec~ric trani~d~er i~entified hy ~e~erencR 23 haYlny iuhstantially th~ same d~me~i~ion~ as the semi-~pherical cup 22 a~ i~ well known to tho~e skillsd in the art, no supplementary dascription thsr~o~
SlO~ H~S~I~ l,~SI~r~ ~T ~ CZ LP T SS~ ûZ:IT SO. ZO~Z
~ 2~3487 ~
appearing neGe~sary. One exa~ple o~ an embodiment o~
such a th~rapy device is, for example, one in the ~orm o~
a ~mi-spherical cup 2~ of 100 m~ diameter, u~ing natural .
focusing a~ a ~ocal leng~h o~ 100 mm, with an o~erating frequen~y of ~bout 1 MHz, uslng on~ sin~l~ piezoelectric transducer elemen~ 23. :~
Tra~sducer element 23 is linked, via a~ ~mpli~ier de~
vice 30, to a si~nal generator 40 which can it~lf b~
controlled by a ~o~trol unit 50. ,:.
~t should be noted tha~, in accord~ce with an~th~r pos~ible embodimen~, ~emi-~pherlcal cup 22 u~ing ~atural focusing can be subdlvided into a~ annula~ a~ay, well kn~wn t~ t.hose ~killed in Sh~ art, ~r l~to a mo~aic al~o :~
known to tho~e ekil~ed ln th~ ~rt, and no supplementary description th~r~o~ ~ppear~ nece~a~y. In chi~ c~
each i~div~dual annular or mosaic-like ~ran~duc~r element i~ linked via ~n ampliSle~ device ~om~ri~i~g ~nd~vidual ampll~iar~ and a d~lay line de~ice ~omprislng individual d~lay lineY, to a common signal gen~ratox ~uch a~ sig~al 20 gen~rator 40 controll~d i~ ~t~ tu~ by control unit ~uch :
a~ con~rol unit so. Th~ control unit th~n controls th~
delay line~ 4~ upplying the delay value nceded by each for ~t~i~g ~oc~l~lng a~ the desired focal len~h.
rh~r~cs to ~hi~; de~ign o~ the apparatu~, clynamlc elec-25 tronic fc~cuE3islg with focal len~th being varied at willcan be Achlq~red.
Con~i~lering the ~?rior art apparatu~ of FI~. 1, w}~en a - :9 convontio~al electronic signal i9 ge~e~ated by generator 40 of, th~: sin~wa~ type ~ shown schamatic~lly at the ou~pu~ ~om ampl~ier 30 and, in mor~ ds~il, ln FIG. 2, for ~xample ~k a frequency of around 1 MHz, n~tural :~focu~ing i8 obtain~d in ~hc foc~l re~ion F dc~inin~ the tr~atment volume T.V~
With ~3uch a con~inuous sinew~ve ~ al, in other - ~
35 words one having a du:ration di~tinctly hiyhe~r than tho . ~ . .
~r~quer~cy~ ~alue per period, which in g~neral ia ~everal second~ compared to a 1 ME~z fre~uer~cy, bubble~ of ga~ : ~
pre~ent in ti~sue or which are 1pontaneou~ly gen~rated by ; ; ~ .
~T0~ H~S~ Cl a~ ~z L~ I C~ 0~:TT S~, Z0~Z .~
"' ~"', ~ 2~43~87 13 :
ultrasound ~av~, id~nti~ied by re~e~ence B, whlch ar~ :
pr~0~nt ahea~ of the ~rious intex~aces, ~or ~xamplo o~
fo~al region F or th~ inter~ac~ with the ~kin S o~ th~
pati~nt P, will ~tart ascillating aft~r ~eYeral pul8e8 at 5 ~requency ~p, called the pumE)ing ~recauer~cy. The dlameter o the ~a~ bubble~ B will incro~6~ ~t e~ch pu16~ duc to the ~o-called recti~ied dlffuslon phe~omenon, to reach a maximu~ value that i~ ch~ract~ristic o~ th~ ~r~quency fp, or Blake thseshold. When the acoust~c field inten~ity lo exceeds th~ ~avi~ation threshold, whl~h pxactically alway~ i9 th~ cafie in th~r~p~uti~ tre~tment, Chc bubble~
~ill implode releasing energy. Thi~ cavitation ~hreshold is identified by the general re~eren~e charact~r C on E'IG. :~ ~o~ ~i~ewa~re signal ir ten~iti~3~ o~ relatively hislh amplitude. ~.
This constituteÆ a ~na~or disad~antag~ in th~s tats ~f the art.
Under th~e aondltions, and with r~f~renc~ to F~G. 3, an apparatu~ ac~ording to t~e ~recent ~nvention iR ~hown 20 generally identi~ied by re~erence numeral 100. The ~ame :
r~f~r~nce nu~eral~ increaeed by lO0 ha~e be~n u~ed to ~::
identl~y tho6~ part~ that are ldentlcal, or operate : ' `
iden~icallr, to ~ho~e in th~ prior art apparatu~. Thus, the actual: ther~py devlce ~ her~ ldanti~ d ~y the ::
25 ~eference 120, th~ semi-~pheslcAl cup by 122 and th~~:
piezoelectric tran8ducer element b~ 123, the a~plifi~r -;~::
device by 130 a~d the el~ctronic ~nal ~enerA~o~ dev~ce and control unit by 140 and 150 respectlvely.
In the ~ramework of the apparatu~ accordl~g t~ the invcntion, the ~i~nal generator devicc 140 s~pplies a wideb~nd electronic ~ignal, identlfied ~y the ra~erence , A.S. ~how~ on FIG. 3, at the output rom ampli~ier device~
130, thi~ belng show~ in mor~ d~tail on FI~. 4. ~.
For thi~ invention, thq ultra~oun~ tran~duc~r can ~ t- ;
3~ ~elf b~ a wideband device, impl~mented as de~cribed pr~iou~ly~
In the inv~ntion and ~or p~ovidin~ an endor~ctal prob~ fo~ pro~tate treatment, it is pre~erred to u~e a Slo~ S~IH ~ CT ~ ~Z L~ I C~ o~:IT S~, Zo~Z
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14 `; ~
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tran~ducer in the form of ~ ~mi-~pherlcal cup of about .~ .
35 mm diame~ex usin~ natural ~ocusing at the focal length of 35: mm, ~h~le, pre~rably, ~ ~ignal h~lng a ce~-ral ~requency of about 2.25 M~z is employed.
5A~ has bee~ ld abo~e, the term wid~b~n~ ~p~ctrum in thi~ pre~ent description and claim~ ~hould b~ takQn to mean that the bandwidth o~ the ~ignal spectrum ie about ~:
50~ o~ the central ~requency. For example, ~or a signal ;~
having a co~tral frequency of 2 MHz, bandwidth wlll be abou~ 1 M~z and will thu~ comprl~e frequencie~ from about 1.5 M~Z to a~out 2.5 M~z. ;
In the invontion, more particularly for the purposo o~ ~edu~ing Qr preve~ting cAvita~ion phenomena re~ulting ~rom the propagation o~ ultrasound wav~ emitted by th~
lS ultrasound tran~ducer element 12~ in the prop~gation-` `
medium PMl, PM2, signal ge~erator 140 ~upplie~ a random or p~e~do-random wide~and elect~onic sign~l, id~t~ d by rof~re~ce A.~. in FI~. 3 And 4. The central ~requen~
cy is genar~lly comp~i3ed be~wee~ 20 MHz a~d 0.5 MH
20It will~ be noted th~t, in tho ~r~m~work o~ tho in~ton~
n, ~e u~e o~ random or pseudo-random slg~al pra~id2~
an ~xcitation ultxa~ound fi~ld ~pectrum consi~ting of a multiple-~r.e~ ncy ~e~t~um, the rand~m app~ara~ e chara~teristic o;E whic~h limits bu~hl~: growth, 80 tha~ the ` ``
l~tter ~arely attal~ the c~l~ical diameter abo~e which cavitation effect~ occur. :: :
Thue, th~ invention makes lt poc~l~le to llmit or prevent cavita~lon phenomena.
Th~ random or p~e~do-ran~om signal ~upplled by.~ignal gcner~to~ 140 i9 o~ th~ type described abov~ and can, ~or examplQ, be a Golay or ~arker coded p~eudo-random ' lelectronic signal, the~e ~eing. w~ll know~ to ~hose skilled in th~ art, paxticularly ~rom th~ pr~ce~ing d~cription.
35An M-~quenc~ p~eudo-ra~dom coded aleatronia 8ignal ca~ a~a. ba employed, this. ~re~erably ha~in~ a~ ' ~lamentary pul~e duration (9) ~heta, compri~ed betw~en ~ .
~' ~'`' ,' ~TOI~I R~)S~IR ~3NIf~ CT ~ CZ L~ T CC~ TC:IT sa. zo~z ~ ~
21~3~8~
0.1 ~s and 1~0 ~, and a repetit~on period T compri~ed ~tw~en 1 ~8 and ~0 ~. -A random ~ignal o~ a Gaua~ia~ o~ Poi~so~ian di~trib-ution type can also be employed.
It ~hould be noted that th~ ctronic 3ignal ~hown in FIG. 3 and in d~tail in FIG. 4 i~ an M-s~que~c~ : .
p~eudo-random al~ctronic ~lgnal the ~eri~d o~ wh~c~ T i~ .
compri~ed between 1 ~g and 10 8, th~ blem~ntary pul~
duration theta (~) being comprlsed betwee~ 0.1 ~ and 100 ~
With re erence to FIG. s, there i8 h¢re shown an apparatu~ making it po9~ible to demon~trate reduction in cavitation when ~l~c~ro~ic signals, or pseudo-random : :
cod~s ~ecordin~ to th~ pros~nt in~ntion ~rc emplo~ed, ~hank~ to the u~e of a luminol. Thia chemical compound i~ known to emit photon~ (~luo~e~c~nce~ when ln th~
presencc oE ca~itation, a~ described in th~ article ~y Fo~lke~ et al, in J. ~coust Soc. ~m. vol 83 of June 88 page 2190-2200 ~ntit,led nCa~itation threRhold mea~ur~m~nts for microcecond leng~h p~l~es o ult.ra~ound~.
Thl~ apparatu~ compri~e~, in the ~chematlc fo~m of: ::
FIG. 5, a fr~quen~y generator 160 a~ociat.ed with a code :
generator l-lQ, the. combinatio~ of: th~ ~w~ g~nerator~ 1~0 25 and 170 ~orre~pondin~ to th~ alectronic signal ~enerator~ ~.
140 ~f FIG. 3, coupled to an amplifier device l~0 ~or . :
~upplyi~ a p~udo-random or ~andom type ele~tronic .:-:.
signal according to the pr~sent inven~ion, for ~xample an :.
: M-6equanc~ ~ignal, ~o tran~duc~r elcment 12~3 placed i~ a - ::
~0 tank 180 containin~ a solution of luml~ol 1~2. In the : ;
luminol ~olution 182, not only i~ tran~ducer lZ3 : :`
i~mer~ed, but a photomultlpli~r 184 device i~ ~ al~o pres~nt, conn~c~ed to a moving-n~edle nanoa~meter 186 pro~iding a mea~u~e~nt in nanoampere~ proportional to 35 the photoluminei~cence obtal~d using th~ luminol. :~ :
The luminol~ ~lution ~82 ~B obta~ned~ro~ a s~lution~ .
of deminerallz~d di~tilled water, isaturatod with air a~
atmo~ph~ric pre~r~, and o~ l~minol L T O [21 ~)S~ C Z L~ I C ~ IS: II S~ . Z O ~ ~ Z
`-~ 21~3~7 ~ ~
..
; ~ . .", .
(a~inophtalhydxazide, 1.4 mmol previou61y dissol~d in hplc-~rade dim~thylsul~oxide ~DM~O)). Th~ ~olution was buf~ered with CAPS ~3-yclohex~lAmino l-propan~ ~ul$onic acid), 25 mmal and balanaed to ~ p~ o~ lO with o.l M :
5 ~oda. .~ ~
For thi~ experiment, the ultra~ou~d tran~ucer :;--. :
elem~nt 123 ~mploy~d had a di~meter of 5 cm, and fo~us~d to 97 mm. The tank wa~ a cylind~ical 40 ml contalner -~
arrang~d horlzontally, with a length of 5 cm in which ~ :
0 foc~in~ e~fect did not partici~ate, th~ energy being : ~p distr~u~ed throughout the t~nk. Tran~ducer re~nant frequency ~as l.ll M~z, ~aid ~alue bei~g obtained at the 80nolumin~cence maximum o$ the wat~r.
The photamultiplier is ~or example ~amamat~u type -~
~74 comprising a len~ optical ~y~tem ~or receiv~ng the fluorescence emltted by the luminol. Tan~ 180 wa~
optically lsola~ed to avoid ~ny light ~nte~S~rence.
Photom~ltlpliar 184 wa~ pow~red by a 6mall g~n~rator not ~hown he~e and the light ~ignAl wa~ read on the ammeter ~0 18~ that integrated th~ total amou~t of l~ht emi~ted by the luminol.
Transducer 123 wa~ conne~eed to power ampll$ier 130, which~ for example~ ~ of ~he Ampar 801, Prana, type ha~ing ~ pa~band ra~glng from o.l to l.a MHz. The electronic ~ignal or M-~equence p~eudo-random code generator w~a m~n~fact-lxod by the INSERM havi~g a period ;; :
T of about 60 m~, and an indivldual pul~ duratlon ~) o~
~ , and W~ s~n~hronlz~d by a HP ~116 A type function generator~. Wattmet~r 132 wa~ a Rhods ~ S~hwarz dlgital 30 watt~et~r refer~nc~ NAP whlch allowed lncident and r~- ;
flected pow~r to ~e mea~urQd. . .
Re~ardi~g wattmeter 132 re~ding~, th~ r~rences ;. .;.
indicated o~ FIG. 5 have the following meaning~
- "2dNC'I = direct puw~r fro~ ~n ~ncoded aignal, in ,;
35 oth~r word~ a si~ewa~e si~nal of the prio~ art; `.; ~.
- PrNS" = r~ ~ect~d power from an uncoded ~ig~al, in ::
other words a ~inewave eignal o~ the prior art~ : .
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' 2143487 ~ -`
- "PdC" - direct power ~rom a coded signal, in other words a random or p~eud~^random type ~ignal o~ th~
l~e~ion;
- "Pr~l' = power r~f l~c~d wt th a coded ~i~nal, in o~her word~ a random or ps~do-random type signal o~ the inv~ntiOn. `
Me~ureme~t were mad~ at di~r~nt power~, ~irs~ly :~ .
with an u~codod ~ignal ~NC) (monochromati~ ~ignal at 1.11 MHz~ o~ contln~ou~ ~inewave o~ the p~ior art, ~u~h as 10 ~i~nal ~1 o~ FI~S. 1 a~d 2, which enabled llne 1 to b~
obtain~d shown by th~3 circle~3 or dot~ in FIG. 6 ~or comparativ~ purpo~e~. Secondly, this ~ame signal :~
: modulated with a p~oudo-random cod~ made it pos~ible to obtai~. ~n M-~eque~c~ p6cudo~random electronic 3ignal accordin~ to the in~ention, a~ shown in Fl~S. 3 ~nd be~ing the re~erence AS, which p~ovided the line identifiad by the diamo~d-~haped point~ on FI~. 6. :~
In both Ca8~8, the ~ignal generated wa~ maintained until a luml~eacence plateau was achieved. The ~olution 20 was i~ct~d lnto the ~anlc m~nually with A 50 ml 3yringe, :; . .
~hi~ alway~ ~in~ done in the same way.
Fo~ ea~h power teeted, m~as~r~ment was r~p~tod time8 wit~ th~ same ~olution. Between ths~ ~aur m~a~ureme~t~., the ~olution wa~ dr~wn o~f ~rom the tii~nk 25 a~d reinj~cted in o~der to ma~ntain a ~on~t~nt de~ree of ~ ;~
saturation. On th~ other hand however, when there was a aP.ang~ iram one power to th~ other, the solution was th~own away and r~newed. .
~ . Temperatur~ w~ r~lat~ely stable (23-2~c), radia-: 30 tion time ~eing ~hort and the tran~ducer beiny only cQ~led rom the back with a cold watex cixc~it (not shown) on its me~al part.
The re~ult~ obtained are gi~en in tabls I ~elow.
Vin ~m~ the lnput voltag~ at the Prana ~ype power amplifier 130. Pd and Pr are, r~a~pectively, the dl~ect r~leat~d.po~rs ~o~d~on w~tt~eter 132, PT~ans bein~
the power tran~mitt~d b~ ~he tr~nsducer ~PTr~ Pd-Pr).
L~lrn i6 thQ luminescenc2 valu~a r~ad on na~oammeter 18~.
0il0~ H~S~ 3~ Ct ~ CZ Lr T CC~ ZC:TT S~i. Zo/~Z
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; 2~3~87 `
18 ~`:
, ~' The indice~ C and NC r~p~ctlvely ~harac~erize a random or pseud~-random ~A.S.) type coded sl~nal according to ~h~ inv~ntion ~FIG~. 3 and 4~ and an ~ncod~d signal, in other words ln sl-type ~in~wav~ according t~ th~ pr~or ~ :
art (FIGS. 1 ~nd 2~.
The lumin~sc~nc~ value~ ob~ain~d from a ai~nal coded according to the inv~ntion are ~h4wn by li~e ~ with diamond-3haped poi~t~ in FI~. 6, line 1 joinin~ the cir~
cle~ or dots ~i~ing the ~igu~e~ or ~ sinewa~ uncoded ~ -~lgnal ac~ording to th~ prior art in FIG. 6, a~ a function of ~ignal powçr tran~mltted by t~e tran~ducer, in Watt~. ~or valu~s b~low lO W, th~ lum~n~scence mea3ur~d for the two ~i~n~ls corresponds to the ~atural lumln~3ce~ce ~ wate~
The cavitation threshold wa~ obt~ined around 12 to 15 W for the uncod~d signal of the continuou~ sinswave type of th~ prior art wh~r~a~ thl~ was n~vor r~ach~d in ~he ~n~ç of power ~mploy~d with ra~dom or pseudo-r~ndom ~pe coded sig~al ~ording t~ ~he pre~ent ~nventio~.
It was no~ po~ble to m~ke tne~suresre~t$ above 40 w without putting the ul~ra~ound trani~ducer 123 at ri~k.
uln P~c~rNa dC ~.5 T,~ un~ _~NC ~Tr~
~4 1~, ~ 0, i. 31. 5lg, 0 2ig 49 12, ~ 12, 5 ~ ~ ~
3g ~,S,3 0,~ 3ig,524,1 130 61 14,7 15,4 ~: '`
44 Z0,0 0,i9 S0,831,1 ~00 ?1 lg,l g,~
. ., :: ..
49 26,3 1,5 6:L,2 37,~ 1400 78 2~,8 24,0 S3 3~,1 1,7 77,8 ~7,~ 2600 ~5 30,4 30,0 62 41,0 2,~ S9,6 ~325 89 ~8,8 3~
~' :....
~huo, it ci~n be aeen that, unexpoctcdly, by using a ; ~
wideband ~lectro~ic ~l~al according t~ the present :~ :
~5 inv~ntion and, ~or example, a p~eudo-random or random :;
typ~ cod~d ~lectronic sl~nal, no cavitation phenomena: -:
a~pear in the rango o~ pow~rs used ~or the exp~im~t, t~ heing.~ re~l~ct~id by the s~it Q~ isteaidy valuois ~or ~:
lumin~scenc~ as a ~unc~ion oE power, in con~raist to line l obtai~ed with a ~inewa~e si~nal o~ the prior art.
, :,,. "
ozn~ H~S~ INI~ Cl ~ CZ L~ I SC~ ~C:TI S~. ZOi~Z
21~3~87 This constitutes a ~urpri~ing result of the pre~3ent in~en~ion FIG. 7 is a his~hly ~;chel~latic repre~entation of th~
opera~cion o a dev1 ce acc~rdln~ to the prior ar'c, in the S pre~l~nc~ of a per~ odlc or ~uaai-perioc3.lc s~'cruc'curel; in FIG. 7, a therapy de~ic~ 200 link~d via an amplifie~ 203 :
to a ~3ignal g~n~rator 204 c~n ~ s~an. ; .
~ me~tioned above, th~ th~rapy devic~ i~ for exampl~ -a ~3emi-spherical cup with natural ~ocu~ing, comprising 10 one or se~reraL transducer element~3 (a single tran~duc~r, or a ge~ of annular ~r mo~aic cer~mic element~
The therapy device ~3etEI up an ultra~ound field 20S
directed towards th~ tr~tment region 2~6. A periodic or ~uasi-periodic ~rUCtUr~ 207 1B dlfipO5~d in th-3 ultra-15 ~ound fi~ld aos between a therapy de~ice ;~00 ar~d thet~eatment reglon ~!0~, r~erence 210 ldentlfying the ~oc~l spo~:. This s~tructllre can i~or example be the rib cage, in the ca~3 of e~xt~rnal l:reatment o~ tumor~ of the l~ver. : ~ .
In devic~s o~ th~3 ~r~o~ ~rt driven by a ao~fentional 20 ~inewave type~ 9igr~al or, more generally, excited by periodlc ~lgnal~, ~uah a p~riodic structure lead~; to the appear~nc~ o~ secondary poirlt~ of ~ocu~ 208, ~0~ ~or ~ida labei~) outisid63 th~ tr~atm~t regio~ as a result of dira~tion ~f ~h~ ultrasQun~ waveY pa~in$ through ~S ~tructure 207. Th~ appearance of ~uch secondary points o~ ~ocu~ ha~ obvious cons~quences ~r the ~f~ty o~
tr~at~ent. Moreover, radiation o~ energy ta the~
secondary points decreai~ee the power radiated to ~ocal point 2~0, and can compromi~e the e~ecti~e~e~3 of 30 treatment. On~ can cay that in this c~n~ig~ation, soc-ondary focusing ph~nomena occur b~hind the p~riodic or f . quaei-periodic structure. In thl~ ispecl~icatlon,l th~, expre~i~ion "behind th~ periodic or qua~i-peri~di~ struc-turc 207" ~hould be tak~n to mean ~down~tream, r~g~r~ing 35 thc propa~ion path of ultrasound wave~, of th~ p~riodic or.qua~ paria~ic structur~ 207~
FI~. 8 ~how0 the ~amo arr~nsement as as in FI~. 7 in a device implementin~ the invention. The i~vention ::
IZ0~ ~S~ CT o~ SZ L~ I SC8 CC :TI S0. ZOi~Z ~ : ~
~ ::
~: :
21 ~ 34 8 7 ~ :
. , "
di~clo~e~ the use of a ~iynal gen~ratOr ~upplyi~l~ a wideband electronlc signal for exciting the therapy device. A~ d~cribed above, ~h~ ~ign~l generator may ~upply a random or pseudo-random ~l~ctronlc ~ignal and, more particul~rly, a Golay or Barker coded paeuda-random elactronlc ~i~nal or an M-~quence pseudo-random coded type electronic signal (of the typ~ dexcribed ab4ve for exampl~
The inv~ntion can also ba cha~terized ln that the therapy devic~ i~ excl~ed b~ a signal h~ving ~n auto~
correlation ~unctlon th~t i~ ~ clo~e ~s possible to a Di~ac ~unction. The signal~ a~o~o have an a~to-correlatlon ~unctio~ w~ich approache~ tha~ of ~ Dirac func~ion.
F~G. ~ lllustrate~ the result6 o~ the invention: the ~econdary point~ o focu~ caused by the periodic or qu~ periodic ~tructu~e have dl~app~ared; the position o~ such ~ocal point~ doe~ ~n fact cs~entially de~end o~
the periodicity of the ~trU~tu~e 207 and the ultrasound frequency. The use o~ wideban~ nal~ cAu~e~ ~he posltion of the ~econdary point o~ focu6 to ~ary d~ring th~ cour~e o~ treatment. In thi~ way, there i~ no longer B local ~uild-up of enersy~outsid~ ~he txeatment region in. ~e ax~ea. surrqur~ding the priD,cipal pQi~t oi~ i~o(~uq 210..
2 ~ l~h~ inv~ntion thus mak~s ~t posslble to decrease the ri~k of producing secondar~ le~lons out~ide the treatment rc~ion, even in the pre~ence of a periodic or qua~
p~riodic struct~re.
. - .
Th~ in~e~tion mak~s it pos~ibl~ t~ achieve ~ccurat~
30 and loc~ ed ~reatme~t, ~n behind a periodic or ;~
, . .. .
guasi-p~riodl~ st~UCture ~uch ~S, for example, treatment ! . 0~ tho llv~r b~hind the rlb cage.
The varlou~ embodiment~ of the in~ention deacribed -~
with re~er~nce to the p~eceding figures can obviously be ~
35 combined. ..
The: pr~ent ln~ention ob~ioui~ly i~clude~ all ~e~ns constituting tschnical e~ui~lents of the ~eans ~:
de~cribed, a~ well aa various co~binations thereo~
:. .
~:
ZZ0121 H::~SUI~I ~3NI~ ) CT d~ CZ L~ I CC~ ~C:IT 98. ZO~
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2 1 ~ 3 ~ ~ 7 ~1 '.' ';'"".'"
Moreo~re~, FIt~;S. 3 to ~ constitu~e an lnte5~ral part of thi~ invention ~nd thu~ o~ tha deEIcription.
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thigh muscle in ~ivo" publish~d in Ultra~ound In Medlcine and Biology, vol. 17, No.~, p~ge~ 157-171, (1991).
Acou~tic ca~it~tion co~er~ any.phy~ical phenomena i~-vol~lng ~h~ activity o~ bubble~ o~ micro-bubbles o~ ~as und~rgoing mo~emen~ as a re~ul~ o an acou~tic ~leld.
Tw~ typa8 C~ cavltat~on can generally be dl~ting-ui~hed:
- st~ble ca~it~tion where ~he walls of the b~bble~
are os~illating at the ~requency of the ultra~ound ~ield without too great a conse~uence ~or the surrounding c~ , but which con~id~rably di~turbs ultra~ound transmi~ion by reflecting or ~aatt~rlng incldant wave~.
Thi~ phenom~non can appear ~t ~ery ~ow ~e~ure lev~l~ a~
300n aa bubble3 ar~ pre~e~t in th~ medium;
~ transitory cavit~tlon where bubble~ e~pand up eo their re#onant ~ize, and than implode viol~ntly. In this ca~o, tha ~n~r~y accumulated by the bubble3 i~ ~imul-ta~eou~ly r~laa~d in the form o~ a shock wa~e, with inten~e heat (generally from 1 ooO ~o 20 000K) and microj~t~ that can ~each ~pee~ o~ loo m/q. All thi~
laad~ to th~ creation o~ ~ree radicals and mechanical de~truQtlon of ~urrounding ~ ue. Generally, this phonomenon a~pe~r~ st~rting ~rom high incident pres~ures which thu~`defi~e~ the cavitation thr~hold~
Every living medium contains ~ ~ertain amount.of di~
~ol~ed gas present in tha form of h~bbl~ mlcronuclai Uhd~r th~ e~ect of an ultr3sound ~ield, the ~ucle~
axpand thr~u~h ~ phy~ic~l phenomenon know~ a~ ~ecti~ied diffuc~on to rea~h ~ cr4tical ~iz~ known ~a th~ ~laka ~hr~shold.
The inventor show~d a while ag~ ln an ar~cle . ientltled ~'Effect_ of cavita~ion in high i~ten~ity therap~utic ultrasound" publi~hed o~ pa~eq 1357 to 13~0 of volum~ 2 (l991) of "Ultra~onic~ Sympo~ium Proc~ding~"
~published by ~.R. ~cAvoy) that thc us~ o~ intensiti~s that were too~ high, gen~rally abo~ 3 000 W~cm2 reduced the therapeu~ic effects of thermal tre~tment involving tis6ue de~tructlon. Thi~ phenomenon can be ~xplain~d by 1~00[21 H~SYI~ Z L~ 1 C~12, 9Z ~ .
' "' ~
~ 2~3~7 ~upposing that at the~ inten3i~ie~, cavitatlon bub~las which may a~ear ahead o~ the ~ocal Ypot ~ct ~ a screen f - .
for in~ident ultr~ou~d wa~e~. Mor~ov~r, with th~
8p~0i~iC aim o~ reducin~ cavitatio~ cffect~, F.J. Fry~
5 stated ln Inter~at~on~l Patent a~llcation Wo-A-8~/0790~ -that it i~ nece~æary to inhibit produation of micro-bubble~ in th~ primary ~ocal ~i~e to a~oid le~ion~
appea~ing out3ide said ~ite (~e~ pa~e 15 of ~aid PAtent application). Under ~hese conditlon~, lt iR ~tated that - :
~e lnten~ity ~hould not exceed 300 w/cm~ at a 1 MHz fraque~cy, o~ Z,10~ WJ~m2 at 4 MHz.
K. ~ynynen al90 ~howed in the above-cited articl~
that an intensity of 700 ~/cm2/MHz ahould ~e con~idered ~b as a ~aximum valu~ ta be u~ed in hyp~rthenmi~ treatment ~, at high~r lev~ vl~ation leads to unpr~dictable ener~y ab60rption.
To ~um up th~ ~tat~ of ~h~ art, cavitation hind~r~
penetration o~ aaousti¢ wave~ into tissue thu~ pre~entlng :~ :
treatme~t fro~ following pred~ctabla lin~s~ Moreov~r, 20 ~a~ltation can lead to uncontroll~d ti~ue de~truction, ~.
outslde the target ~olume. It is thu~ appropriate, ..
regardles~ o~ the applieation envisaged ~in oth~r word~
thermal tre~tm~nt at high tempexature for tis~u~ de- ~:
~truction, ar at mo.d~r~t~ ta~aperature or hyperth~3rm~a), ~ - .
: ~ to increase cavitation onoet thre~hold~
To avoid cavl~ation, the only recomm~ndation~ that can be f ourld in the p3~ior art consist eith~ ln reducirlg ~`~
acou~tic lnten~lty, or em~ ttlng in a di~con~cinuous ~ann~x, u~ing ~a~e trai~ of de~ermined duratlon, and.
30 respectin~ A waiting ti~e betwe~n th~ tr~in~, or, yet a~ain, increa6ing ~mis~ion ~requency.
However, rqducing a~oustic iate~ity or u~ing di~con- ;
tinuous emi~ion lead~ to a los~ o~ ac~ustic ener~y ~.
tran~mitted t~ the medium, which llmi~a temporatur~ rise 35 or increa~a tr~a~ment duration. Furthermore, in~reasing ~.
em~sion freguency limlts the depth o~. treat~e~t~
absorption by ti~ue being directly proportlo~al to ~requenc~, a~ d~s~ribed by Daniel3 et al., in the journ~l sno~~S~ Cl 8~ CZ L~ I 6~ ~Z:II S~. Zo~bZ ;
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~`:` 21~3~87 :
"Ultrasound in Medicine and Blology" ~rol . 13, No. 9, ~19~7) in th~ articl~ ~ntitled "Ultra~onically induced ga~ bubble~ producti~ in ag~r bas~d gel~n. I~ ~hould ~lso be noted th~t, in th~ prior art, continuou~
sinewav~s are ~mployed ~or ti~u~ heating, and thu~
emis~ion du~atio~ i~ far higher than ~ignal period.
U~ually, in~onification of ti~ue ~or ~e~eral ~econ~ at a fres[uency c:omprlsed between 1 and 5 MHz l~ envisaged.
Certain authors h~re, on the other hand, consid~red 10 u61ng acou~tlc waves o~ a pul~ed typ~s, with a duration of the order of se~rer~l perio~, in other word~ ~veral rnlcrosecond~;, but for a complet~ly dif ~erent pu~pose, ~pec:i~ically eith~r the c~e~truction o~ concretlon~
~li tho~rl~t~tlc~n), or for diagnc~ (DQPP1er ultra~;ound : . .
~canning).
The ca~itation phenomena produced by such pul~es have bee~ ~tudied. For example, ~owlh!~ and Crum in an articl~ entitled " Cavitation thre~hold measurementa ~or microsecond langth pu~ 8 of ultrasound~ publi~hed i~ J.
20 Acou~tic 90c. A~. 83 ~ un~ 1988, inv~a~tigat~s th~
evolution o~ c~itatlon thrc~hol~ as a ~unctiQn o~ pu180 ,' widt~ and pul~e fr~qu~ncy. ~imilarly, Deliu8, while studying ~a~ltation pr~duced by lithotripter~ reaommended ~educing acou~tic wav~ repctition ra~e~ (see "~f~ects of lithotripter ~hoak wave~ on ti~u~ and mat~rial~
Frontier3 on non-lin~ar acoustic~, ~dited by M.F. ~amil- ~;
ton and D.T. ~ k~tock, Ele~vlor Scienc~ Publishers, London lg90).
How~er,. puLae ~thods. do not make it po~siblo to ` ~::
produco ~ temper~tu~e rl~e in tis~uo since e~ch pul~e o~ly tr~nsports small amount of cner~y, and the pulses n~ed to be spaced. It i~ thu~ not possible to asslmilate work don~ with the~e wave~ with thq work at the basis of thi~ pre~ent in~ntion.
T~u~r the. prl~ciple aim o~ th~ prc~ent invention is ;~
to resolve the new tochnical problom of pro~i~ing a ~olution enablln~ maximum energy to be supplied to the ~00~1 EI~S~ ST ~ CZ L~ I CC~ Z:TI S~. ZO~Z
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21~3~87 . . .
medium, pref~rably ~he ti~ue o~ a livln~ ~ing, in ;~
particular an a~imal or huma~ being, ln the ~hortest possibl~ time and p~ef erD~ly reducing or preventing the oc~urr~nce o~ ea~itation ~henome~a .
A further aim ~ the in~ention i~ to re301ve the n~w t~chni~al p~o~lem o~ providlng a solution enabling maximum ~rgy to be ~upplled to th~ m~ium, pr~arably ~he tia~ue of ~ li~ing baing, in par~icular an animal or huma~ bei~g, in the ~horte~t possible time, whil~
simult~ously enæuring ~a~e a~d ef~ec~ive control Of heat de~o~it, thu~ making lt po~ le eithsr to provi~e mod~rat~ ther~al ~reatm~nt in ~he ~ramewor~ of hyper-thexmla, or to carry out thermal tr~atmont at high tcmpcrature~ tQ achi~Ye tis~u~ de~tructiQn, pre~era~ly . .;~
15 reducing or llmiting ca~ita~ion phenomen~. -- .-~
Moreo~er, the in~ention r~sol~es th~ ~ew p~oblem of 3ec~ndary focusing whieh can occur wben perlodic ~r ~-`
qu~ai-periodic ~tructures are pre~ent on the path betw~Qn the emi~sion de~ice and the re~ion to be treated. ::
~0 The preæent inv~ntibn h~s the ~urther aim o :~
re~olvlng th~ abo~e technical probl~mg in ~ ~imple, r~liabl_, inexpen~lve mann~r makin~ widespread indu6trial ~nd madical uae ~os~lble. : :.:
The pre~ent invention provides a ~tl~iactory ~5 901ut~0n ~or th~ firs~ time to the technic~l problems ~.
defin~d abo~e, and has ~urth~ir tcchnical Advantagee which ~ ::
wlll hecome more clear ~rom tho det~iled de~cription which ~ollow~, including the attach~d drawing~ which con~tttute an integral p~rt thereo~. :
Thu~, ~cc~rding to a flrst as~ect ~ there i~ provided a method ~0~ ~enerat~ng ultrasound waves i~ a ~opagation !` mediu~ comp~i~ln~ acti~ating at least one ul~ra~ound ~ransducer ~lement by an elec~ronic signal ~upplied by a ::
sign~l generator and xedu~l~g or pre~enting c~Yltation :
35 ph~nomon~ re~ulting from ths propaga~ion of ultra~ound ::
wave~ emi:tted by the ul~rasound tranedu~ier element wlthin.
the pxopa~a~ion m~dium by the u~e of a siynal ~n~r~to~
supplying a wid~band elect~onlc signa~
L00~ H~S~IH ~ CT or ~Z L~ T S6~ LZ:TI 9fl, zo~z 2~3~87 ~i , ! .
rn thi~ tnvention~ in oth~r words in the de~cription and claim~, ths oxpre~ion "wideband" ~or th~ epectrum o~
an eLectronic ~ign~l m~an~ that ~ignal sp~ctrum bandwidth i~ a~out 50~ of ~he central fr~-quoncy. For ~xnmpl~, for a ~ignal of central frequenc~ 2 M~z, bandwidth will b~
around 1 M~ and will thu~ co~r ~requensieY ~a~y~ rom abou~ 1. 5 MH3 to about 2.5 M~z.
I~ ~ pref~rred em~odlment, a ~ignal generator ~:.
supplying a continuou~ rand~m or ~eudo-random electronic ~ignal i~ em~loyed.
Throughout this speci~catio~, the term ~con~inuous"
should be tak~n to msan that th~ duratlon of emlsslon o~
the ~ignal i~ ~ery much long~r than t~ period of the slgn~l, a~ ha~ al~ead~ been sald in the introductlon 15 abov~. ~
Acco~ding to on~ preferred feature, the a~ovesaid .~:;
ignal gen~rator s~upplies a p~e:udo-ra2~dom electronic ~i~nal o~ th~ Gau~sian or Poi~onian d~tributio~ t~pe.
Su~h ~ignal can t~ l~ally be obtained fro~ a sourc~ a ~.
20thormal noi~e ampllfi~3d by e~le~ronic ampllfication. .~
According to a further advantageous ~eature, the ~aid .:~ .. o ~igne.l t3en~3rator ~upplie~ a l?oeudo random electronic c~ignal using G~lay coding. ~ -~ccording ~t~:a ~u~er ad~antagOEtaus fe~ture, the 6aid ZS~i~rnal g~nerator ~upplieY a }~eudo-random el~ctronic si~n~l using Barktr coding.
Ac~ os:din~ to still a ~urthex ~dvantagtaou~ ft3ature of thti~ in~r~ntlon~ ~he E3aid signAl generator ~u~pli~ a c:oded el.qctronic ~ sign~l o~ M-s~t~ut3nce pseudo-randc~m type .
30M-~e~ena~ signal~ also referred to ac maximum l~ngth - :: -binary acquence~ are of th~ typ~ de~ribed b~ Jeasl-Y~e~
Chapelon in Chapter 6, on pag~ 225 to 23~, partlcularly .
page 230 onwards of the ~oc~k "Progr~:ss in medic~
imaging" edit~d by Profeasor Newhou~e arld pu~ hed by .
3SSpring~r Vexlag, New Yorlc, 1988 whlch i3 incorporated ~ * :~
her~i~ by. ~e~renc~
Such M-~equ~n~ or ~olay or Bark(3r pl3~udo-random ~ .
cod~d signal~ can be employed directly or can pha3e- or 800~ H~S~IH ~ Sl ~ SZ ~ I SS~3 LZ:~T g~, ZOi~Z .'~
7 `~
frequency-modula'ce an electronic eignal thc carrier f requ~ncy of whlch correspond~ eo the tr~n~ducer ' nominal- op~r~:n~ Sr~uen~.
Coded signals of the M-3equence p~eudo-random type 5 are pa~icularly pre~erred. Such slgnalE~ are prf3c~ sely de~cribed in ~Progre~ med~e~ glngn. ~riep~
they co~i~t of b.inary 8ignal~ buil~ up by p~oudo-random repetitio~ of J?ul~^~ of elem~ntary duration E:Ach of said sequ~nc~ss is xe~p~ated with a ;repetition p~riod T
lO 'chat i8 chara~terl~tic of the M ~equonce.
A more~ pr~ci~ deacription of an M s~quonc~ ~ignal c~n be pro~ided with referenc~ to FIG. 4 attached, ~ ~
- element~ry pulse duration 11011 O.l ~L9 C: u ~ 100 ~3, '.
ideally akou~ ~ fL3, - re~p~ti~ion period T: 1 ~9 c T c l~ ~, ideally com-prl~ed b~ws~n ~.5 and 5 ~
The p~eudo-ra~dom typ~ cod~d signal~, parti~ularly the currently pre~erred M ~equenc~ p~eudo-rando~ type sllgnals can readily be obtained usin~ el~c:tx~onie circuita zo well lcnown to tho~ ~killsd in th~ art.
Th~ u~ o~ l3uch wideband electronic E;i~als, ~ ~
pref~rably random or p~eudo-random, mak~s it pos~ibls to :: :
ac~iav~ b~tter c~ntrol o~ heat depo~ition and to a~oid tempe~atu~e. inc~ease di~turbancc by ~econdary e~e~t~
25 such as ca~lt~ion, ~hu~ e~abling spontaneous tissue ::
dsstruction to ~e a~olded part~cularly in the ~aee o~
~oder~t.~ he~tlng used ln hyperthe~mla..
9ooondly, conaidering hlgh-intensity u~, the invention ~k~ . po~ible/ to employ high~r intensiti~s :
3nd to redu~, for a given ultrasound dose, firing duration and, con6equently, the dur~tion of creatment, whils a~oi~ing cavltation phenomena ~hus m~king iC
po~ible to carry out treat~ent of tumore in living b~ing3, in particular animals or human beings, ~ith ~5 higher l~vel o~ ~a~ety whil~ reducing the risk o~ damage at ~ari~us.in~r~e~:.
From a ~econd a~pect, the present in~cntion also pro-vides a therap~ apparatu~ comprising an ac~ual therapy 600 SHIH ~ ) Sl ~ CZ L~ T CC~ 8Z:IT S6. Z0~2 2~3~87 device eo~prising at lea~t on~ ultra~ound therapy tran~duecr Ql~nt and ~ ~ignal ~cner~tor ~upplylng an ~lectro~ic signal to said u}tra~ound tran~ducex elem~nt, in whieh the ~i~nal g~neratDr ~upplies a wideband ~lectro~ic ~lgnal o~ th~ random or pseudo-r~ndom typo.
ln on~ pr~ferred embodiment, the ~ignal ~enerator . ::
.supplie~ a ~aua~lan or Poi8~0nlan di~tri~ution type random ~ignal. ::
~n another pre~erred embodim~nt, the ~ignal generator supplie~ a ~olay coded or a Barker Goded pseu~o-~andom ~ignal. ~;
In ~nother pre~err~d embodiment, the ~ignal ~e~erator ~upplie~ ~n M-sequ~nce paeudo-random type coded :~
elec~rontc si$~al................................................... , -~ Thl~ M-s~quence p6eudo-~andom type coded ~lectronic 3~nal p~e~erably has an elementary pul~e d~ration ~e) .
theta comp~i~e~ between 0.1 ~ and 100 ~ and 1~ ld0ally of About 1 ~ nd a period of repet$tion T ao~pri~ed ~etween 1 ~ and 10 ~ and ~deally compri~ed bRtween 0.58 and 5 ~
In eithar a~pect o~ th~ invention, to increase the ef~ectiven~ of ca~it~ effec~ x~duction or preYention, a~ ultraso.und tran~ducer which pre~erably i~ it~el$ ~ ` ?`, w.ideban~, 18' u~d, in o~hc~ words the ultrasound ;:`~
transducer gener~te~ ultra~ound wa~es when excited by a 8~ ~nal th~ reque~cy of w~ich ie qubstantially di~erent ~ro~ its nomlnal ~requQnay.
U~ually, tWo type~ of tran~duc~r can b~ u~ed for gen~
er*ttn~ ~ontinuou~ ultra80und waves ~or. th~rapeutic. ::~
30 purposes. ~he~e comprise, f~r~tly, conv~ntional -~
ult~asoun~ tran~ducors e~se~eially consl~ing o~
piezoelectric ceramia. Such ceramlc~ ha~ an acou~tic impedance whlch i~ v~ry differene ~rom that of the ;~
propagation medlum and, as a re8ul~ o~ ~hi~, ~hei~
35 coupling with ~ald medium i~ poor. Thi~ re~ult~ in .
s.trong.vibration3 ~f the ceramic when it i~ ~xcit~d hy ~n elect~lc ~ig~al, the re~ulting ~ra~ound transduccr ~:
havlng a narrow ~re9uency bandwidth. ~`
OTO~ H~S~ Cl 0~ ~Z L~ T ~C~ qZ:TT S~. ZO~PZ ~ -;
3~87 `;
g I .....
, For ther~py ~arrled out ~o d~te u31~g ul~r~ound waves ~ ouch tran~ducer~ are suitable a~ the control ~ignalg ~r~ ~hemsclve~ of tha ~arrow ba~d ty~e.
In ~he fr~mework o~ this lnv~ntlon, the ~requency band of the ultra~ound tran~ducer~ i~ widened ~y the ap~lic~tlon o~ dif~erent type~ of tr~atment to the ceramic surf~c~, th~se modifying ultra~ound coupliny with the propagAtlon madiu~ Particularly) a layer o~
matexial~ haYing an Acoustic ~mpedance lntermedlate ` `:
betw~en that of ceramic and the propagation m~dium of ap~roprlate thickne~ i8 d~posit~d in this cas~ on th~
ceramic, such a layer being re~rr~d to ~ a quarter-wav~
l~yer. A 30~called backin~ layer c~uld aleo be depo~ited ` :: :
on the back o~ the c~ramic between the latter and the :`
15 air. The~e two ty~e~ of treatment of the ceramic enabl~ :
a wideb~nd ultra~ound transducer to be obt~ined. ::
Another ~ype o~ wideba~d tran8duco~ can b~ obtaiuod ;~
u~ing composite type materials, thi~ being particularly ; ~-suitable for impl~m~ntation in the present invention ~or ao reducing or pr~v~nting ca~itation e~fect~
Thi~ make~ 1~ po~3ibl~ to obtain the de~termining technical ad~ant~ges stated aboYe.
AccordlnS~ to a further ~pect, the invention di~close~ the use, i~: a therapy apparatua comprising at 2 5lcaJt o~e ultrasound trarl~duc~r and .D ~ l gen~rzltor supplyin~ an electro~i~ signal to ~aid tr~n~ducor, of a wid~band ~lectr~nle ~l~nal f~r r~duciny or preventing s2condary fo~uein~ phenomena bqhind ~ perlodic or qu~ per~ Qdic ~;truc:ture~
30Th~ ~or ex~m~le mak~a it po~sibl~ to tre~t the li~er be~l~d the rib cag~i by reducing or prev~nting le~ion~ due ~o seconda~y facu~ing or side lobe phenomena.
In one eimbodlm~nt o~ this third a~ect of the inv~ntion, the wide~and ~l~ctroni~ nal i9 0~ the 35 random or p~eudo-random typo. ::
The ~ideband RlQctronic ~ignal ca~ he a Gauss;~ian or ~ :
Poi~sonian di~trlbutlon typ0 random ~ign~
. .
............. . .... ~ .... .... . ~
TT~ H~S~ Cl ~ CZ L~ I SS~ aZ:TI S~. ZO~Z ~ -:
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-- 21~3487 ' ' ':
The wideband e~l~ctronic ~i~nal can al~o be a Barker coded ~r Golay cod~d ps~udo-random slgnal.
Fo~ t~e wideband elec~tronic ~ignal, one c~n u~3e a -:
M- se~ue~ce pseudo-random typ~ coded el~ctronic si~nal 5 of a ~r~ue~cy havin~ a~ elementary pul~e du~at ion compri~ed be~twQ~n 0.1 ,us3 and 100 ~ and ideally o~ about :~
3, and ~ p~rlo~l o~ repet~ tion T com~ri~3~3d between 1 and 10 E~ and id~ally comprised between 0.5e and 5 8. : ::;~
The ele~ronic wideband ~3ignal may also ha~e an lo autocorrelation function apl?ro~chlng a Dirac functlon. .
~ urther characte~ri~;tiaæ of the invention will ~ecome cl~3ar rom ~he detail~3d de6cription that i~ollows, including the dra~ing~ which ~onstitut0 an integral part th~r~a. and:th~ cl~im~ ~ccompa~yi~ thia deecription Th~ in~rention will now b~ d~cribed on the basis o~ a : -currently pr~~rred ~mbodlme~t thereo~ slmply by way o~
illu8tr~tlon whlch in no m~nn~r ~hould be con~dered a~
::~: .,:: -: . :::
limiting the scope on the lnvention, with rQ~Qr~nc~ to ;.. ~.--thc attached d~aw~n~s.
FI~ a h~ghly ~chematic r~pr_sentatiqn of a ~:.; :"
known therapy dovic~ for per~ormln~ t~srapy o~ the ti39U~
of ~ llYin~ ~lng, compri~ing a sinyle- or multl-tran~
d~a~r d~ e ha~l~g on~ or ~v~ral piezoelec~ic tran~
25 du~rs, in th~ ~oxm of a 0am~-~ph~rical cup ~llowing :'. :
~eo~etrlcal ~ocusin~ on the proRagation axis Vi9~ bl~ in FI~. 2~ : `
FIG. 2 ~hows a curve in the form of a 6inewa~e a~ a functlon o~ ~ime; t on th~ x-axi~ and.a~plituda A on the y-axl~, according to the prlor art as ~mployed in an ultra~ound wav~ yen~rating device o~ FIG. l; ,~
. i FI~.... 3 i~ a highly ~chcm~tic ~iew of ~ therapy devicq "`~
according to the pres~nt invcntiorl for carryin~ out ;~
th~rapy of li~ing bel~g ti~ue, comprising a wid~band ..
35 elec~ronic ~ignal g~neratlng device, ~aid signal being pr~f~r~bly rand~m ar p~ud~-randcm, delivered to the .
piezoele~tric transducer devlc~ ~or generating an ultraaound wave, the r~ndo~ or pseudo-random ~ignal being ,.:
ZTo~ ~S~IH ~ CT ~t cz L~ I cc~ ~Z:TT 9~. zof~z ~ -:, -. :., ; ~ - ~ : .
~ 21~3~87 .. . ..
11 ' - ' shown diagramma~cally in FIG. 3, ~nd in det~il ln Fr~. 4 ~ a 4~nctlon of ~ime expressc~ in microseconds on the x-axi~, with ~mplitude on thc y-axi~;
FI~. S i~ ~ block di~gram of a ~ctup making it 5 possi~le ~o claarly bring to light reduction in cavita-tio~ by u~lng a random or ~eudo-random ty~e electronic signal for axciting the ultra~ound tran~ducer;
FIG. ~ show~ r~ult~ obtainca with the apparatua in ~IG. 5 ln ~he ~orm of a graph ln whlch the l~ne : :
identiied by the reference 2 corrc~ondo to the random or p~eudo-r~ndo~ ~i~nal accordin~ to the in~ention of FIG~. 3 and 4 joining the points ~how~ by the - o -~ign~, ~nd th~ llne be~ring the re~er~nca 1 re~ul~ ~xom th~ u~ o~ ~ ~inew~v~ ~ig~al according to ~hc prior art :~:
employed in FI~5. 1 and 2, and ~o~in~ the ~olnt~
a~ a ~unc~ion ~ pow~r tran~mltted by the ~ran~duc~r expre~ed in Watt~ on the x-axi~, the valu~ in nano-ampere~ pro~ided by an ammeter inte~ra~ln~ the total amount of light cmit~ed ~y ch~ luMinol ernployed ~eing ~o indi~ated on the y-axiB;
- FI~. 7 ~how~ ~chematically the operation o~ a p~io~
art device in tho pr~senc~ o~ a periodic or quasi-pe~lodi~ atructur~; and - FIa. 8 is a isichematic re~ei~i~tatlon ~imilar to that in FI~. 7 in a d~ice imPlem~n~ins ~he in~ntion.
Wi~h r~fer~n~ to FIQ. 1, th~re i~ i~hown dlagram~ati-cally a known therapy d~vic~ g~n~rially idonti~i~d by re~ere~ce numeral lO, ~or carryir~ out th~rap~ o~ ~he ti~ue o~'ia llving being.
Thi~ tharapy apparatus 10 compriae~ an actual theripy device whlch here takes the form o~ a 3~mispherical cup ~ :~
22 using natural focusing compri~iing one or se~eral piczoeloctric trAnsducer element~, in pii~rticular a :~
singl~ m~nt piezoelec~ric trani~d~er i~entified hy ~e~erencR 23 haYlny iuhstantially th~ same d~me~i~ion~ as the semi-~pherical cup 22 a~ i~ well known to tho~e skillsd in the art, no supplementary dascription thsr~o~
SlO~ H~S~I~ l,~SI~r~ ~T ~ CZ LP T SS~ ûZ:IT SO. ZO~Z
~ 2~3487 ~
appearing neGe~sary. One exa~ple o~ an embodiment o~
such a th~rapy device is, for example, one in the ~orm o~
a ~mi-spherical cup 2~ of 100 m~ diameter, u~ing natural .
focusing a~ a ~ocal leng~h o~ 100 mm, with an o~erating frequen~y of ~bout 1 MHz, uslng on~ sin~l~ piezoelectric transducer elemen~ 23. :~
Tra~sducer element 23 is linked, via a~ ~mpli~ier de~
vice 30, to a si~nal generator 40 which can it~lf b~
controlled by a ~o~trol unit 50. ,:.
~t should be noted tha~, in accord~ce with an~th~r pos~ible embodimen~, ~emi-~pherlcal cup 22 u~ing ~atural focusing can be subdlvided into a~ annula~ a~ay, well kn~wn t~ t.hose ~killed in Sh~ art, ~r l~to a mo~aic al~o :~
known to tho~e ekil~ed ln th~ ~rt, and no supplementary description th~r~o~ ~ppear~ nece~a~y. In chi~ c~
each i~div~dual annular or mosaic-like ~ran~duc~r element i~ linked via ~n ampliSle~ device ~om~ri~i~g ~nd~vidual ampll~iar~ and a d~lay line de~ice ~omprislng individual d~lay lineY, to a common signal gen~ratox ~uch a~ sig~al 20 gen~rator 40 controll~d i~ ~t~ tu~ by control unit ~uch :
a~ con~rol unit so. Th~ control unit th~n controls th~
delay line~ 4~ upplying the delay value nceded by each for ~t~i~g ~oc~l~lng a~ the desired focal len~h.
rh~r~cs to ~hi~; de~ign o~ the apparatu~, clynamlc elec-25 tronic fc~cuE3islg with focal len~th being varied at willcan be Achlq~red.
Con~i~lering the ~?rior art apparatu~ of FI~. 1, w}~en a - :9 convontio~al electronic signal i9 ge~e~ated by generator 40 of, th~: sin~wa~ type ~ shown schamatic~lly at the ou~pu~ ~om ampl~ier 30 and, in mor~ ds~il, ln FIG. 2, for ~xample ~k a frequency of around 1 MHz, n~tural :~focu~ing i8 obtain~d in ~hc foc~l re~ion F dc~inin~ the tr~atment volume T.V~
With ~3uch a con~inuous sinew~ve ~ al, in other - ~
35 words one having a du:ration di~tinctly hiyhe~r than tho . ~ . .
~r~quer~cy~ ~alue per period, which in g~neral ia ~everal second~ compared to a 1 ME~z fre~uer~cy, bubble~ of ga~ : ~
pre~ent in ti~sue or which are 1pontaneou~ly gen~rated by ; ; ~ .
~T0~ H~S~ Cl a~ ~z L~ I C~ 0~:TT S~, Z0~Z .~
"' ~"', ~ 2~43~87 13 :
ultrasound ~av~, id~nti~ied by re~e~ence B, whlch ar~ :
pr~0~nt ahea~ of the ~rious intex~aces, ~or ~xamplo o~
fo~al region F or th~ inter~ac~ with the ~kin S o~ th~
pati~nt P, will ~tart ascillating aft~r ~eYeral pul8e8 at 5 ~requency ~p, called the pumE)ing ~recauer~cy. The dlameter o the ~a~ bubble~ B will incro~6~ ~t e~ch pu16~ duc to the ~o-called recti~ied dlffuslon phe~omenon, to reach a maximu~ value that i~ ch~ract~ristic o~ th~ ~r~quency fp, or Blake thseshold. When the acoust~c field inten~ity lo exceeds th~ ~avi~ation threshold, whl~h pxactically alway~ i9 th~ cafie in th~r~p~uti~ tre~tment, Chc bubble~
~ill implode releasing energy. Thi~ cavitation ~hreshold is identified by the general re~eren~e charact~r C on E'IG. :~ ~o~ ~i~ewa~re signal ir ten~iti~3~ o~ relatively hislh amplitude. ~.
This constituteÆ a ~na~or disad~antag~ in th~s tats ~f the art.
Under th~e aondltions, and with r~f~renc~ to F~G. 3, an apparatu~ ac~ording to t~e ~recent ~nvention iR ~hown 20 generally identi~ied by re~erence numeral 100. The ~ame :
r~f~r~nce nu~eral~ increaeed by lO0 ha~e be~n u~ed to ~::
identl~y tho6~ part~ that are ldentlcal, or operate : ' `
iden~icallr, to ~ho~e in th~ prior art apparatu~. Thus, the actual: ther~py devlce ~ her~ ldanti~ d ~y the ::
25 ~eference 120, th~ semi-~pheslcAl cup by 122 and th~~:
piezoelectric tran8ducer element b~ 123, the a~plifi~r -;~::
device by 130 a~d the el~ctronic ~nal ~enerA~o~ dev~ce and control unit by 140 and 150 respectlvely.
In the ~ramework of the apparatu~ accordl~g t~ the invcntion, the ~i~nal generator devicc 140 s~pplies a wideb~nd electronic ~ignal, identlfied ~y the ra~erence , A.S. ~how~ on FIG. 3, at the output rom ampli~ier device~
130, thi~ belng show~ in mor~ d~tail on FI~. 4. ~.
For thi~ invention, thq ultra~oun~ tran~duc~r can ~ t- ;
3~ ~elf b~ a wideband device, impl~mented as de~cribed pr~iou~ly~
In the inv~ntion and ~or p~ovidin~ an endor~ctal prob~ fo~ pro~tate treatment, it is pre~erred to u~e a Slo~ S~IH ~ CT ~ ~Z L~ I C~ o~:IT S~, Zo~Z
~3~8~
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14 `; ~
~ ~: ,: :::;
tran~ducer in the form of ~ ~mi-~pherlcal cup of about .~ .
35 mm diame~ex usin~ natural ~ocusing at the focal length of 35: mm, ~h~le, pre~rably, ~ ~ignal h~lng a ce~-ral ~requency of about 2.25 M~z is employed.
5A~ has bee~ ld abo~e, the term wid~b~n~ ~p~ctrum in thi~ pre~ent description and claim~ ~hould b~ takQn to mean that the bandwidth o~ the ~ignal spectrum ie about ~:
50~ o~ the central ~requency. For example, ~or a signal ;~
having a co~tral frequency of 2 MHz, bandwidth wlll be abou~ 1 M~z and will thu~ comprl~e frequencie~ from about 1.5 M~Z to a~out 2.5 M~z. ;
In the invontion, more particularly for the purposo o~ ~edu~ing Qr preve~ting cAvita~ion phenomena re~ulting ~rom the propagation o~ ultrasound wav~ emitted by th~
lS ultrasound tran~ducer element 12~ in the prop~gation-` `
medium PMl, PM2, signal ge~erator 140 ~upplie~ a random or p~e~do-random wide~and elect~onic sign~l, id~t~ d by rof~re~ce A.~. in FI~. 3 And 4. The central ~requen~
cy is genar~lly comp~i3ed be~wee~ 20 MHz a~d 0.5 MH
20It will~ be noted th~t, in tho ~r~m~work o~ tho in~ton~
n, ~e u~e o~ random or pseudo-random slg~al pra~id2~
an ~xcitation ultxa~ound fi~ld ~pectrum consi~ting of a multiple-~r.e~ ncy ~e~t~um, the rand~m app~ara~ e chara~teristic o;E whic~h limits bu~hl~: growth, 80 tha~ the ` ``
l~tter ~arely attal~ the c~l~ical diameter abo~e which cavitation effect~ occur. :: :
Thue, th~ invention makes lt poc~l~le to llmit or prevent cavita~lon phenomena.
Th~ random or p~e~do-ran~om signal ~upplled by.~ignal gcner~to~ 140 i9 o~ th~ type described abov~ and can, ~or examplQ, be a Golay or ~arker coded p~eudo-random ' lelectronic signal, the~e ~eing. w~ll know~ to ~hose skilled in th~ art, paxticularly ~rom th~ pr~ce~ing d~cription.
35An M-~quenc~ p~eudo-ra~dom coded aleatronia 8ignal ca~ a~a. ba employed, this. ~re~erably ha~in~ a~ ' ~lamentary pul~e duration (9) ~heta, compri~ed betw~en ~ .
~' ~'`' ,' ~TOI~I R~)S~IR ~3NIf~ CT ~ CZ L~ T CC~ TC:IT sa. zo~z ~ ~
21~3~8~
0.1 ~s and 1~0 ~, and a repetit~on period T compri~ed ~tw~en 1 ~8 and ~0 ~. -A random ~ignal o~ a Gaua~ia~ o~ Poi~so~ian di~trib-ution type can also be employed.
It ~hould be noted that th~ ctronic 3ignal ~hown in FIG. 3 and in d~tail in FIG. 4 i~ an M-s~que~c~ : .
p~eudo-random al~ctronic ~lgnal the ~eri~d o~ wh~c~ T i~ .
compri~ed between 1 ~g and 10 8, th~ blem~ntary pul~
duration theta (~) being comprlsed betwee~ 0.1 ~ and 100 ~
With re erence to FIG. s, there i8 h¢re shown an apparatu~ making it po9~ible to demon~trate reduction in cavitation when ~l~c~ro~ic signals, or pseudo-random : :
cod~s ~ecordin~ to th~ pros~nt in~ntion ~rc emplo~ed, ~hank~ to the u~e of a luminol. Thia chemical compound i~ known to emit photon~ (~luo~e~c~nce~ when ln th~
presencc oE ca~itation, a~ described in th~ article ~y Fo~lke~ et al, in J. ~coust Soc. ~m. vol 83 of June 88 page 2190-2200 ~ntit,led nCa~itation threRhold mea~ur~m~nts for microcecond leng~h p~l~es o ult.ra~ound~.
Thl~ apparatu~ compri~e~, in the ~chematlc fo~m of: ::
FIG. 5, a fr~quen~y generator 160 a~ociat.ed with a code :
generator l-lQ, the. combinatio~ of: th~ ~w~ g~nerator~ 1~0 25 and 170 ~orre~pondin~ to th~ alectronic signal ~enerator~ ~.
140 ~f FIG. 3, coupled to an amplifier device l~0 ~or . :
~upplyi~ a p~udo-random or ~andom type ele~tronic .:-:.
signal according to the pr~sent inven~ion, for ~xample an :.
: M-6equanc~ ~ignal, ~o tran~duc~r elcment 12~3 placed i~ a - ::
~0 tank 180 containin~ a solution of luml~ol 1~2. In the : ;
luminol ~olution 182, not only i~ tran~ducer lZ3 : :`
i~mer~ed, but a photomultlpli~r 184 device i~ ~ al~o pres~nt, conn~c~ed to a moving-n~edle nanoa~meter 186 pro~iding a mea~u~e~nt in nanoampere~ proportional to 35 the photoluminei~cence obtal~d using th~ luminol. :~ :
The luminol~ ~lution ~82 ~B obta~ned~ro~ a s~lution~ .
of deminerallz~d di~tilled water, isaturatod with air a~
atmo~ph~ric pre~r~, and o~ l~minol L T O [21 ~)S~ C Z L~ I C ~ IS: II S~ . Z O ~ ~ Z
`-~ 21~3~7 ~ ~
..
; ~ . .", .
(a~inophtalhydxazide, 1.4 mmol previou61y dissol~d in hplc-~rade dim~thylsul~oxide ~DM~O)). Th~ ~olution was buf~ered with CAPS ~3-yclohex~lAmino l-propan~ ~ul$onic acid), 25 mmal and balanaed to ~ p~ o~ lO with o.l M :
5 ~oda. .~ ~
For thi~ experiment, the ultra~ou~d tran~ucer :;--. :
elem~nt 123 ~mploy~d had a di~meter of 5 cm, and fo~us~d to 97 mm. The tank wa~ a cylind~ical 40 ml contalner -~
arrang~d horlzontally, with a length of 5 cm in which ~ :
0 foc~in~ e~fect did not partici~ate, th~ energy being : ~p distr~u~ed throughout the t~nk. Tran~ducer re~nant frequency ~as l.ll M~z, ~aid ~alue bei~g obtained at the 80nolumin~cence maximum o$ the wat~r.
The photamultiplier is ~or example ~amamat~u type -~
~74 comprising a len~ optical ~y~tem ~or receiv~ng the fluorescence emltted by the luminol. Tan~ 180 wa~
optically lsola~ed to avoid ~ny light ~nte~S~rence.
Photom~ltlpliar 184 wa~ pow~red by a 6mall g~n~rator not ~hown he~e and the light ~ignAl wa~ read on the ammeter ~0 18~ that integrated th~ total amou~t of l~ht emi~ted by the luminol.
Transducer 123 wa~ conne~eed to power ampll$ier 130, which~ for example~ ~ of ~he Ampar 801, Prana, type ha~ing ~ pa~band ra~glng from o.l to l.a MHz. The electronic ~ignal or M-~equence p~eudo-random code generator w~a m~n~fact-lxod by the INSERM havi~g a period ;; :
T of about 60 m~, and an indivldual pul~ duratlon ~) o~
~ , and W~ s~n~hronlz~d by a HP ~116 A type function generator~. Wattmet~r 132 wa~ a Rhods ~ S~hwarz dlgital 30 watt~et~r refer~nc~ NAP whlch allowed lncident and r~- ;
flected pow~r to ~e mea~urQd. . .
Re~ardi~g wattmeter 132 re~ding~, th~ r~rences ;. .;.
indicated o~ FIG. 5 have the following meaning~
- "2dNC'I = direct puw~r fro~ ~n ~ncoded aignal, in ,;
35 oth~r word~ a si~ewa~e si~nal of the prio~ art; `.; ~.
- PrNS" = r~ ~ect~d power from an uncoded ~ig~al, in ::
other words a ~inewave eignal o~ the prior art~ : .
,:, ''' " ' ' .'' , , ,:, 8To~ ~S~IH ~ cT ~ CZ L~ l s~ ZC:TI 9~. zo~Z .:
' 2143487 ~ -`
- "PdC" - direct power ~rom a coded signal, in other words a random or p~eud~^random type ~ignal o~ th~
l~e~ion;
- "Pr~l' = power r~f l~c~d wt th a coded ~i~nal, in o~her word~ a random or ps~do-random type signal o~ the inv~ntiOn. `
Me~ureme~t were mad~ at di~r~nt power~, ~irs~ly :~ .
with an u~codod ~ignal ~NC) (monochromati~ ~ignal at 1.11 MHz~ o~ contln~ou~ ~inewave o~ the p~ior art, ~u~h as 10 ~i~nal ~1 o~ FI~S. 1 a~d 2, which enabled llne 1 to b~
obtain~d shown by th~3 circle~3 or dot~ in FIG. 6 ~or comparativ~ purpo~e~. Secondly, this ~ame signal :~
: modulated with a p~oudo-random cod~ made it pos~ible to obtai~. ~n M-~eque~c~ p6cudo~random electronic 3ignal accordin~ to the in~ention, a~ shown in Fl~S. 3 ~nd be~ing the re~erence AS, which p~ovided the line identifiad by the diamo~d-~haped point~ on FI~. 6. :~
In both Ca8~8, the ~ignal generated wa~ maintained until a luml~eacence plateau was achieved. The ~olution 20 was i~ct~d lnto the ~anlc m~nually with A 50 ml 3yringe, :; . .
~hi~ alway~ ~in~ done in the same way.
Fo~ ea~h power teeted, m~as~r~ment was r~p~tod time8 wit~ th~ same ~olution. Between ths~ ~aur m~a~ureme~t~., the ~olution wa~ dr~wn o~f ~rom the tii~nk 25 a~d reinj~cted in o~der to ma~ntain a ~on~t~nt de~ree of ~ ;~
saturation. On th~ other hand however, when there was a aP.ang~ iram one power to th~ other, the solution was th~own away and r~newed. .
~ . Temperatur~ w~ r~lat~ely stable (23-2~c), radia-: 30 tion time ~eing ~hort and the tran~ducer beiny only cQ~led rom the back with a cold watex cixc~it (not shown) on its me~al part.
The re~ult~ obtained are gi~en in tabls I ~elow.
Vin ~m~ the lnput voltag~ at the Prana ~ype power amplifier 130. Pd and Pr are, r~a~pectively, the dl~ect r~leat~d.po~rs ~o~d~on w~tt~eter 132, PT~ans bein~
the power tran~mitt~d b~ ~he tr~nsducer ~PTr~ Pd-Pr).
L~lrn i6 thQ luminescenc2 valu~a r~ad on na~oammeter 18~.
0il0~ H~S~ 3~ Ct ~ CZ Lr T CC~ ZC:TT S~i. Zo/~Z
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,j .
; 2~3~87 `
18 ~`:
, ~' The indice~ C and NC r~p~ctlvely ~harac~erize a random or pseud~-random ~A.S.) type coded sl~nal according to ~h~ inv~ntion ~FIG~. 3 and 4~ and an ~ncod~d signal, in other words ln sl-type ~in~wav~ according t~ th~ pr~or ~ :
art (FIGS. 1 ~nd 2~.
The lumin~sc~nc~ value~ ob~ain~d from a ai~nal coded according to the inv~ntion are ~h4wn by li~e ~ with diamond-3haped poi~t~ in FI~. 6, line 1 joinin~ the cir~
cle~ or dots ~i~ing the ~igu~e~ or ~ sinewa~ uncoded ~ -~lgnal ac~ording to th~ prior art in FIG. 6, a~ a function of ~ignal powçr tran~mltted by t~e tran~ducer, in Watt~. ~or valu~s b~low lO W, th~ lum~n~scence mea3ur~d for the two ~i~n~ls corresponds to the ~atural lumln~3ce~ce ~ wate~
The cavitation threshold wa~ obt~ined around 12 to 15 W for the uncod~d signal of the continuou~ sinswave type of th~ prior art wh~r~a~ thl~ was n~vor r~ach~d in ~he ~n~ç of power ~mploy~d with ra~dom or pseudo-r~ndom ~pe coded sig~al ~ording t~ ~he pre~ent ~nventio~.
It was no~ po~ble to m~ke tne~suresre~t$ above 40 w without putting the ul~ra~ound trani~ducer 123 at ri~k.
uln P~c~rNa dC ~.5 T,~ un~ _~NC ~Tr~
~4 1~, ~ 0, i. 31. 5lg, 0 2ig 49 12, ~ 12, 5 ~ ~ ~
3g ~,S,3 0,~ 3ig,524,1 130 61 14,7 15,4 ~: '`
44 Z0,0 0,i9 S0,831,1 ~00 ?1 lg,l g,~
. ., :: ..
49 26,3 1,5 6:L,2 37,~ 1400 78 2~,8 24,0 S3 3~,1 1,7 77,8 ~7,~ 2600 ~5 30,4 30,0 62 41,0 2,~ S9,6 ~325 89 ~8,8 3~
~' :....
~huo, it ci~n be aeen that, unexpoctcdly, by using a ; ~
wideband ~lectro~ic ~l~al according t~ the present :~ :
~5 inv~ntion and, ~or example, a p~eudo-random or random :;
typ~ cod~d ~lectronic sl~nal, no cavitation phenomena: -:
a~pear in the rango o~ pow~rs used ~or the exp~im~t, t~ heing.~ re~l~ct~id by the s~it Q~ isteaidy valuois ~or ~:
lumin~scenc~ as a ~unc~ion oE power, in con~raist to line l obtai~ed with a ~inewa~e si~nal o~ the prior art.
, :,,. "
ozn~ H~S~ INI~ Cl ~ CZ L~ I SC~ ~C:TI S~. ZOi~Z
21~3~87 This constitutes a ~urpri~ing result of the pre~3ent in~en~ion FIG. 7 is a his~hly ~;chel~latic repre~entation of th~
opera~cion o a dev1 ce acc~rdln~ to the prior ar'c, in the S pre~l~nc~ of a per~ odlc or ~uaai-perioc3.lc s~'cruc'curel; in FIG. 7, a therapy de~ic~ 200 link~d via an amplifie~ 203 :
to a ~3ignal g~n~rator 204 c~n ~ s~an. ; .
~ me~tioned above, th~ th~rapy devic~ i~ for exampl~ -a ~3emi-spherical cup with natural ~ocu~ing, comprising 10 one or se~reraL transducer element~3 (a single tran~duc~r, or a ge~ of annular ~r mo~aic cer~mic element~
The therapy device ~3etEI up an ultra~ound field 20S
directed towards th~ tr~tment region 2~6. A periodic or ~uasi-periodic ~rUCtUr~ 207 1B dlfipO5~d in th-3 ultra-15 ~ound fi~ld aos between a therapy de~ice ;~00 ar~d thet~eatment reglon ~!0~, r~erence 210 ldentlfying the ~oc~l spo~:. This s~tructllre can i~or example be the rib cage, in the ca~3 of e~xt~rnal l:reatment o~ tumor~ of the l~ver. : ~ .
In devic~s o~ th~3 ~r~o~ ~rt driven by a ao~fentional 20 ~inewave type~ 9igr~al or, more generally, excited by periodlc ~lgnal~, ~uah a p~riodic structure lead~; to the appear~nc~ o~ secondary poirlt~ of ~ocu~ 208, ~0~ ~or ~ida labei~) outisid63 th~ tr~atm~t regio~ as a result of dira~tion ~f ~h~ ultrasQun~ waveY pa~in$ through ~S ~tructure 207. Th~ appearance of ~uch secondary points o~ ~ocu~ ha~ obvious cons~quences ~r the ~f~ty o~
tr~at~ent. Moreover, radiation o~ energy ta the~
secondary points decreai~ee the power radiated to ~ocal point 2~0, and can compromi~e the e~ecti~e~e~3 of 30 treatment. On~ can cay that in this c~n~ig~ation, soc-ondary focusing ph~nomena occur b~hind the p~riodic or f . quaei-periodic structure. In thl~ ispecl~icatlon,l th~, expre~i~ion "behind th~ periodic or qua~i-peri~di~ struc-turc 207" ~hould be tak~n to mean ~down~tream, r~g~r~ing 35 thc propa~ion path of ultrasound wave~, of th~ p~riodic or.qua~ paria~ic structur~ 207~
FI~. 8 ~how0 the ~amo arr~nsement as as in FI~. 7 in a device implementin~ the invention. The i~vention ::
IZ0~ ~S~ CT o~ SZ L~ I SC8 CC :TI S0. ZOi~Z ~ : ~
~ ::
~: :
21 ~ 34 8 7 ~ :
. , "
di~clo~e~ the use of a ~iynal gen~ratOr ~upplyi~l~ a wideband electronlc signal for exciting the therapy device. A~ d~cribed above, ~h~ ~ign~l generator may ~upply a random or pseudo-random ~l~ctronlc ~ignal and, more particul~rly, a Golay or Barker coded paeuda-random elactronlc ~i~nal or an M-~quence pseudo-random coded type electronic signal (of the typ~ dexcribed ab4ve for exampl~
The inv~ntion can also ba cha~terized ln that the therapy devic~ i~ excl~ed b~ a signal h~ving ~n auto~
correlation ~unctlon th~t i~ ~ clo~e ~s possible to a Di~ac ~unction. The signal~ a~o~o have an a~to-correlatlon ~unctio~ w~ich approache~ tha~ of ~ Dirac func~ion.
F~G. ~ lllustrate~ the result6 o~ the invention: the ~econdary point~ o focu~ caused by the periodic or qu~ periodic ~tructu~e have dl~app~ared; the position o~ such ~ocal point~ doe~ ~n fact cs~entially de~end o~
the periodicity of the ~trU~tu~e 207 and the ultrasound frequency. The use o~ wideban~ nal~ cAu~e~ ~he posltion of the ~econdary point o~ focu6 to ~ary d~ring th~ cour~e o~ treatment. In thi~ way, there i~ no longer B local ~uild-up of enersy~outsid~ ~he txeatment region in. ~e ax~ea. surrqur~ding the priD,cipal pQi~t oi~ i~o(~uq 210..
2 ~ l~h~ inv~ntion thus mak~s ~t posslble to decrease the ri~k of producing secondar~ le~lons out~ide the treatment rc~ion, even in the pre~ence of a periodic or qua~
p~riodic struct~re.
. - .
Th~ in~e~tion mak~s it pos~ibl~ t~ achieve ~ccurat~
30 and loc~ ed ~reatme~t, ~n behind a periodic or ;~
, . .. .
guasi-p~riodl~ st~UCture ~uch ~S, for example, treatment ! . 0~ tho llv~r b~hind the rlb cage.
The varlou~ embodiment~ of the in~ention deacribed -~
with re~er~nce to the p~eceding figures can obviously be ~
35 combined. ..
The: pr~ent ln~ention ob~ioui~ly i~clude~ all ~e~ns constituting tschnical e~ui~lents of the ~eans ~:
de~cribed, a~ well aa various co~binations thereo~
:. .
~:
ZZ0121 H::~SUI~I ~3NI~ ) CT d~ CZ L~ I CC~ ~C:IT 98. ZO~
'~';
2 1 ~ 3 ~ ~ 7 ~1 '.' ';'"".'"
Moreo~re~, FIt~;S. 3 to ~ constitu~e an lnte5~ral part of thi~ invention ~nd thu~ o~ tha deEIcription.
:,' ~ .' ' , ~ : ; , ~ - .
~ ~ :
, . ..
.
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- :` ~
; ;: .: ~, . . ! ; , .
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`';"'~',:,"':,
Claims (17)
1.- A method for generating ultrasound waves in a propagation medium comprising activating at least one ultrasound transducer element by an electronic signal supplied by a signal generator and reducing or preventing cavitation phenomena resulting from the propagation of ultrasound waves emitted by the ultrasound transducer element within the propagation medium by the use of a signal generator supplying a wideband electronic signal.
2.- A method according to claim 1, wherein said signal generator is a signal generator supplying a random or pseudo-random electronic signal.
3.- A method according to claim 1, wherein said signal generator supplies a Golay coded pseudo-random electronic signal.
4.- A method according to claim 1, wherein said signal generator supplies a Barker coded pseudo-random electronic signal.
5.- A method according to claim 1, wherein said signal generator supplies an M-sequence pseudo-random type coded electronic signal, preferably with an elementary pulse duration comprised between 0.1 µs and 100 µs, ideally of 1 µs and a period of repetition T
comprised between 1 µs and 10 s, and ideally of between 0.5 and 5 s.
comprised between 1 µs and 10 s, and ideally of between 0.5 and 5 s.
6.- Therapy apparatus comprising an actual therapy device (120) comprising at least one ultrasound therapy transducer element (123) and a signal generator (140) supplying an electronic signal to said ultrasound transducer element, wherein said signal generator (140) supplies a wideband electronic signal of the random or pseudo-random type (A.S.).
7.- The therapy apparatus according to claim 6, wherein said signal generator (14) supplies a Gaussian or Poissonian distribution type random signal.
8.- The therapy apparatus according to claim 7, wherein said signal generator (140) supplies an M-sequence pseudo-random type coded electronic signal, with an elementary pulse duration comprised between 0.1 µs and 100 µs and ideally of about 1 µs and 10 s and radially comprised between 0.5s and 5 s.
9.- The therapy apparatus according to claim 6, wherein said signal generator (140) supplies a Golay coded or Barker coded pseudo-random signal.
10.- The therapy apparatus according to one of claims 6 to 9, wherein said ultrasound transducer element (123) is a wideband transducer element.
11.- The therapy apparatus according to one of claims 6 to 10, wherein said ultrasound transducer element (123) is selected from the group comprising a single element, an annular array or a mosaic of ultrasound transducer elements, said therapy ultrasound transducer element being preferably of the focused type, particularly using geometrical focusing, and for example being in the form of a semi-spherical cup.
12.- The use, in a therapy apparatus comprising at least one ultrasound transducer (200) and a signal generator (204) supplying an electronic signal to said transducer, or a wideband electronic signal for reducing or preventing secondary focusing phenomena behind a periodic or quasi -periodic structure (207).
13.- The use of a wideband electronic signal according to claim 12, wherein said wideband electronic signal is of the random or pseudo-random type.
14.- The use of a wideband electronic signal according to claim 12, wherein said wideband electronic signal is a Gaussian or Poissonian distribution type random signal.
15.- The use of a wideband electronic signal according to claim 12, wherein said wideband electronic signal is a Barker coded or Golay coded pseudo-random signal.
16.- The use of a wideband electronic signal according to claim 12 wherein said wideband electronic signal is a M-sequence pseudo-random type coded electronic signal of a frequency having an elementary pulse duration comprised between 0.1 µs and 100 µs and ideally of about 1 µs, and a period of repetition T
comprised between 1 µs and 10 s and ideally comprised between 0.5s and 5 s.
comprised between 1 µs and 10 s and ideally comprised between 0.5s and 5 s.
17.- The use of a wideband electronic signal according to claim 12 wherein said electronic wideband signal has an autocorrelation function approaching a Dirac function.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9402322A FR2717942B1 (en) | 1994-03-01 | 1994-03-01 | Method and apparatus for therapy generating high intensity ultrasound with controlled cavitation effect. |
| FR9402322 | 1994-03-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2143487A1 true CA2143487A1 (en) | 1995-09-02 |
Family
ID=9460537
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002143487A Abandoned CA2143487A1 (en) | 1994-03-01 | 1995-02-27 | High-intensity ultrasound therapy method and apparatus with controlled cavitation effect and reduced side lobes |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0670147B1 (en) |
| AT (1) | ATE204721T1 (en) |
| CA (1) | CA2143487A1 (en) |
| DE (1) | DE69522352T2 (en) |
| DK (1) | DK0670147T3 (en) |
| FR (1) | FR2717942B1 (en) |
Families Citing this family (30)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5694936A (en) * | 1994-09-17 | 1997-12-09 | Kabushiki Kaisha Toshiba | Ultrasonic apparatus for thermotherapy with variable frequency for suppressing cavitation |
| EP1453425B1 (en) | 2001-12-03 | 2006-03-08 | Ekos Corporation | Catheter with multiple ultrasound radiating members |
| US8226629B1 (en) | 2002-04-01 | 2012-07-24 | Ekos Corporation | Ultrasonic catheter power control |
| FR2849781B1 (en) | 2003-01-14 | 2005-03-25 | Edap S A | THERAPY PROBE |
| US8535228B2 (en) | 2004-10-06 | 2013-09-17 | Guided Therapy Systems, Llc | Method and system for noninvasive face lifts and deep tissue tightening |
| US8444562B2 (en) | 2004-10-06 | 2013-05-21 | Guided Therapy Systems, Llc | System and method for treating muscle, tendon, ligament and cartilage tissue |
| US10864385B2 (en) | 2004-09-24 | 2020-12-15 | Guided Therapy Systems, Llc | Rejuvenating skin by heating tissue for cosmetic treatment of the face and body |
| US8066641B2 (en) | 2004-10-06 | 2011-11-29 | Guided Therapy Systems, L.L.C. | Method and system for treating photoaged tissue |
| US11883688B2 (en) | 2004-10-06 | 2024-01-30 | Guided Therapy Systems, Llc | Energy based fat reduction |
| US9827449B2 (en) | 2004-10-06 | 2017-11-28 | Guided Therapy Systems, L.L.C. | Systems for treating skin laxity |
| US9694212B2 (en) | 2004-10-06 | 2017-07-04 | Guided Therapy Systems, Llc | Method and system for ultrasound treatment of skin |
| US8133180B2 (en) | 2004-10-06 | 2012-03-13 | Guided Therapy Systems, L.L.C. | Method and system for treating cellulite |
| US20060111744A1 (en) | 2004-10-13 | 2006-05-25 | Guided Therapy Systems, L.L.C. | Method and system for treatment of sweat glands |
| US11235179B2 (en) | 2004-10-06 | 2022-02-01 | Guided Therapy Systems, Llc | Energy based skin gland treatment |
| US8690778B2 (en) | 2004-10-06 | 2014-04-08 | Guided Therapy Systems, Llc | Energy-based tissue tightening |
| US11724133B2 (en) | 2004-10-07 | 2023-08-15 | Guided Therapy Systems, Llc | Ultrasound probe for treatment of skin |
| US11207548B2 (en) | 2004-10-07 | 2021-12-28 | Guided Therapy Systems, L.L.C. | Ultrasound probe for treating skin laxity |
| US10182833B2 (en) | 2007-01-08 | 2019-01-22 | Ekos Corporation | Power parameters for ultrasonic catheter |
| WO2008086372A1 (en) | 2007-01-08 | 2008-07-17 | Ekos Corporation | Power parameters for ultrasonic catheter |
| EP2170181B1 (en) | 2007-06-22 | 2014-04-16 | Ekos Corporation | Method and apparatus for treatment of intracranial hemorrhages |
| EP2282675B1 (en) | 2008-06-06 | 2016-04-20 | Ulthera, Inc. | System for cosmetic treatment and imaging |
| KR20110101204A (en) | 2008-12-24 | 2011-09-15 | 가이디드 테라피 시스템스, 엘.엘.씨. | Methods and systems for fat reduction and/or cellulite treatment |
| ES2503140T3 (en) | 2009-07-03 | 2014-10-06 | Ekos Corporation | Power parameters for ultrasonic catheter |
| US9510802B2 (en) | 2012-09-21 | 2016-12-06 | Guided Therapy Systems, Llc | Reflective ultrasound technology for dermatological treatments |
| CN204637350U (en) | 2013-03-08 | 2015-09-16 | 奥赛拉公司 | Aesthstic imaging and processing system, multifocal processing system and perform the system of aesthetic procedure |
| CA2944707C (en) | 2014-04-18 | 2023-01-24 | Ulthera, Inc. | Band transducer ultrasound therapy |
| EP3307388B1 (en) | 2015-06-10 | 2022-06-22 | Ekos Corporation | Ultrasound catheter |
| ES2939604T3 (en) | 2016-01-18 | 2023-04-25 | Ulthera Inc | Compact ultrasonic device having an annular ultrasonic array peripherally electrically connected to a flexible printed circuit board |
| AU2017312527B2 (en) | 2016-08-16 | 2022-03-17 | Ulthera, Inc. | Systems and methods for cosmetic ultrasound treatment of skin |
| US11944849B2 (en) | 2018-02-20 | 2024-04-02 | Ulthera, Inc. | Systems and methods for combined cosmetic treatment of cellulite with ultrasound |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3866068A (en) * | 1974-03-20 | 1975-02-11 | Lewis Corp | Frequency varying oscillator circuit vibratory cleaning apparatus |
| AU8151275A (en) * | 1974-06-04 | 1976-12-02 | Mitsubishi Heavy Ind Ltd | Axial-flow fan |
| US4736130A (en) * | 1987-01-09 | 1988-04-05 | Puskas William L | Multiparameter generator for ultrasonic transducers |
| FR2685211B1 (en) * | 1991-12-20 | 1997-05-30 | Technomed Int Sa | ULTRASONIC THERAPY APPARATUS EMITTING ULTRASONIC WAVES PRODUCING THERMAL AND CAVITATION EFFECTS. |
-
1994
- 1994-03-01 FR FR9402322A patent/FR2717942B1/en not_active Expired - Fee Related
-
1995
- 1995-02-24 AT AT95400392T patent/ATE204721T1/en not_active IP Right Cessation
- 1995-02-24 DE DE69522352T patent/DE69522352T2/en not_active Expired - Fee Related
- 1995-02-24 DK DK95400392T patent/DK0670147T3/en active
- 1995-02-24 EP EP95400392A patent/EP0670147B1/en not_active Expired - Lifetime
- 1995-02-27 CA CA002143487A patent/CA2143487A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0670147B1 (en) | 2001-08-29 |
| DK0670147T3 (en) | 2001-12-03 |
| FR2717942B1 (en) | 1996-05-31 |
| FR2717942A1 (en) | 1995-09-29 |
| ATE204721T1 (en) | 2001-09-15 |
| DE69522352T2 (en) | 2002-06-13 |
| EP0670147A1 (en) | 1995-09-06 |
| DE69522352D1 (en) | 2001-10-04 |
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