Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS2249610 A
Publication typeGrant
Publication dateJul 15, 1941
Filing dateJun 13, 1936
Priority dateJun 13, 1936
Publication numberUS 2249610 A, US 2249610A, US-A-2249610, US2249610 A, US2249610A
InventorsRobert F James, Hart Deryl
Original AssigneeWestinghouse Electric & Mfg Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and apparatus for medical purposes
US 2249610 A
Images(4)
Previous page
Next page
Description  (OCR text may contain errors)

jui? 15,3941 R. F. JAMES ETAL I 2,249,610

METHOD AND APPARATUS PQR MEDICAL PURPOSES Filed June 1:5.,-1936 4 sheets-speak 1 ATTORN July 15, 1941. R, `F, JAMES :TAL 2,249,610

METHOD AD APPARATUS FOR MEDICAL PURPOSES Filed June-13, .195e 4 sheets-sheet 2y -ATTORN July 15 1941- R. F. v.lAMl-:ss 5ML y I 2,249,610

METHOD AND APPARATUS FOR MEDICAL PURPOSES y Filed June 15. 193e 4 Sheets-sheet s za 1y a 'X "t u TT' fflfffrl -f- I 2000 2500A .3000 l 55'00 4000 suffi/mph E56/0N off/fmfair Pyme-AM mea/mv 3 Fra/v new? amr/mf 1. daer/wy Z.

, July `15, 1941.

R. F. JAMES. ETAL METHOD AND APPARATUS FbR MEDICAL PURPosEs Filed June 1s. 195s 4'sheets-sheet 4 Patented July 15,1941

METHonAND APrAnA'rUs Fon MEDICAL PURPOSES Robert F. James, Mahwah, N. J., and Deryl Hart,

Durham, N. C., assignors, by direct and mesne assignments, to Westinghouse Electric and Manufacturing Company, East Pittsburgh, Pa.,

a corporation of Pennsylvania Application June 13, 1936, Serial No. 85,692

(Cl. 12B-396) -9 Claims.

'Ihis invention relates to the 4.science of medicine and surgery and is more particularly concerned with minimizing the danger of infection from organisms transmitted through the air between patientand attendant or between patient and patient.

Despite the precautions ordinarily 'taken prior to and during the care and treatment of patients, in^many cases serious complications result from infection of the patient. Heretofore the belief more generally prevailed that infections resulted from skin' contamination or improperly sterilized supplies in View of which the most drastic precautions were observed in eliminating this,

source of infection.` For example, the time of sterilization was increased, the skin of the patient was most carefully washed with soap and water and then again washed with alcohol and ether and other antiseptic solutions. However, such precautions have not eliminated the danger of infection, as for example, during operations. It was felt that the cause of infection must lie somewhere else than on the supplies and upon roof of the building in which the rooms were ,located.

' These precautions, however, were not effective in materially reducing the number f pathogenic organisms in the air which caus infection. Therefore, it was found necessary to investigate this matter further in order to ascertain if the air was not impregnated with pathogenic organisms from other sources.

It was suspected that the noses and throats l and possibly the skin of the individuals using the rooms were responsible for this contamination ofl the air. Cultures taken from the noses and 'throats of these individuals proved this to b e the fact and, therefore, as a precautionary measure, the number of individuals entering the rooms was reduced to a minimum. Masks were worn over the noses and mouths at all times, and all persistent carriers/of pathogenic bacteria, such for example, as Staphylococcus aureus or streptococcus, were kept out of the rooms at all times.

Although these precautions, together with the precautions previously mentionedin connection with clean air and care of the room, reduced air contamination by from to 80% nevertheless the number of organisms in the air were not reduced suiiiciently to eliminate all infections and it was found that in almost every infected case the organism cultured from a Wound, for example, was identical with the culture from the air'- in thefroom.

Upon investigating this situation, it was quite definitely shown by numerous culture tests that most of the infections were caused by the nemolytic Staphylococcus aureus, and that the organisms entered a wound, for example, from the air rather than from the skin of the patient, and

further that. the air was contaminated by the personnelentering the room and also by the patients.

Particularly in surgical cases it was ascertained that, while infections with suppuration were rare, culture of the drainage tracts and incisions showed the presence of the hemolytic staphyloooccus aureus, or other pathogenic bacteria, (as high as 33% -in thoracoplastics). Additionally -in such cases, all supplies and all procedures in operating room technique were checked by cultures and found to be satisfactory except for the air whichA was heavily contaminated. The Staphylococcus aureus was usually present at times in large numbers. The operating room personnel and the general population were found at times to have the Staphylococcus aureus (frequently hemolytic) in the nose and throat in as high as 78% of cases and apparently they were the source of the air contamination. As stated heretofore with all the precautions mentioned above, it was not possible to reduce the number of organisms in the air sufficiently to eliminate all infections.

A/Inendeavoring to more precisely control this situation and eliminate the danger. of infections from air-home pathogenic organisms, resort was made to the use of ultra-violet lights, such as commonly foundlupon the market. In one of the it was demonstrated that a'sprayedcultureof hemolytic Staphylococcus aureus could be killed.

at a distance of eight feet from the lamp withinK sixty seconds. This sterilization of the air was also attempted by means of a carbon arc lamp,

but which had, apparently, no eifect on the organisms.

These sources of radiation, however, for many reasons were not suitable'. for the purpose because of other unsatisfactory effects on the patient. Inasmuch as the primary concern was the elimination from the air of the infection-causing organisms, so that such organisms would not drop into an incision, for example, and cause infection; and simultaneously therewith prevent any detrimental reactions in the patient, a device was selected capable of emitting radiations which killed the objectionable organisms and which, at the same time, did not produce any detrimental reactions in the patient. The radiation device used was of special design and provided a high intensity of radiations in the region of 2500 A. u. wave band, together with a lesser intensity of radiations in the wave band region around and below 2000 A. u. with a relatively low intensity of radiations in the Wave lengths above 2600 A. u. It was found that by placing such devices in the form of a cluster at a distance of approximately six to eighteen inches above the operating teams heads, for example, the radiations therefrom produced remarkable results.

For example, in a hundred patients operated on under this cluster of specially designed and positioned radiation devices, it was found that the patients had no infected wounds; no wound cultures taken showed any growth; there was less temperature elevation during the post-operative course; the patients experienced less pain; and a smoother and more rapid convalescence was had by the patients.

found niet the wounds .hee1ed better than in the control animals.` It was further found that there was no increase in adhesions following an Yexposure of the peritoneumto this radiation.

` granisms in the air coming from the noses and These operations were run in parallel with a control group of cases and in all of the control group it was found that in 5 to 35% of the cases infection had occurred; the' temperature during the post-operative course Awas much higher;the patients experienced more pain; and the convalescence was not as smooth and rapid as was the case with the patients who were operated on while the devices were functioning to emit their radiations.

In the preliminary tests to determine the ability of these tubes to perform satisfactorily for the intended purpose, cultures of the hemolytic staphylocdccus aureus and a mixture of many organisms were first sprayed on culture plates and exposed to the radiations from these devices and it was found that the organisms were killed vat a distance of ve feet from the devices within of the air was reduced by from 60 to 90%. It ,was

also determined that the air in an entire room could not be completely sterilized with only eight of the devices, and that when the tubes were turned oif re-contamination quickly occurred if people were present. v

'To determine that the radiations from these tubes would produce nov detrimental effects upon a patient, blonde individuals were subjected /to the radiations from eight devices for a periodof eighty minutes at a distance of five feet. Such individuals received only a slight reddening of the area of the skin exposed to the radiations, this reddening clearing up within twenty-foury hours.

Wounds in rats and dogs werel exposed to the 4 radiation from the eight devices et e distance df five feet for from 30 to 90 minutes and it wasv throats of the operating team together with those which might float in from the surrounding air. The position of these lamps with respect to the patient was such that the `more highly bactericidal radiations therefrom were so absorbed by the intervening air as to be reduced to a negligible intensity. At the same time, the intensity of the radiations in the region of the 2500 A. u. wave band, these also being bactericidal in character, was such as to project such radiations to the region or zone in the vicinity of the patient, thus destroying any pathogenic organisms which might oat in from the surrounding air without l, passing through the zone of intense radiation inf the vicinity of the operating teams heads.

Likewise the intensity of the radiations from the device in the region above 2600 A. u., that is in the so-called erythema regionn was so reduced in intensity that at the distance lthe device was placed above the patient, such radiations would not cause any detrimental reactions in the patient. By thus controlling the lintensity and character of the radiations emanating from these devices, the air-borne organisms, which were concentrated in the region adjacent the throats and noses of the operating team, were effectively destroyed and, at the saine time, the pathogenic organisms in the region adjacent the patient were likewise destroyed. Since the radiations in this latter region were of such character and of' insuiiicient intensity to cause any detrimental reaction upon the patient, no harm befell the patient. Such detrimental reaction would be, for example, an irritation of the tissue such as a violent reddening, blistering, or erythema of the skin with discomfort following thereafter.

From the results obtained it is apparent that the intensity and character of the radiations are such as to produce a beneficial reaction in the patient. Although it is not known precisely the mechanism by which this benecial reaction is produced, it is quite clear from these results that such a beneficial reaction was secured, as

all patients operated upon under the devices recovered more rapidly. experienced less pain and discomfort, and the incisions quickly healed with freedom from infection.

In 'such operations known as thoracoplasties, many surgeons make the incision for the second operation approximately an inch from the first scar because of the danger ofencountering a small focus of viable organisms which might inoculate the new incision. When performing such operations under the radiation devices, it has been found that this old technique may be altered by -making the second incision in the first without danger of inoculation of the new incision. n

It is, therefore, an object of the invention to provide a method whereby a patient may be treated in such a manner and yunder suchconacter around the patient as to be lethal to bac- ,teria and, non-injurious, and benecial to thev devices in a series of cases where infection was od of -performing surgical operations by destroying air-borne organisms in and about the patient lo during such operations by means of radiations in that portion of the spectrum which is particularly lethal to such organisms.

Another object is to improve the method of performing surgical operations or treatments by immersing the patient and 'the attendants in preselected radiations of such intensity and wave length as to be lethal to organisms coming within the sphere vof action of such radiations and which simultaneously therewith will not injure, but will produce instead a beneiicial action upon, the patient.

A more specific object of the invention is to perform surgical voperations or treatments upon a patient in a zone of radiations of such intensity and character as to effectively destroy bacteria in the vicinityof the operating teams or attendants heads, and simultaneously provide a zone of radiations of such intensity and charment of the radiation devices with respect toa patient vbeing operated upon and with respect to the operating team; l

Fig. 2 is an elevation of the radiation device unit;

Fig. 3 is a bottom plan view of the radiation device unit;

Fig. 4 is a partial longitudinal sectional view of one of the radiation devices;

Fig. 5 is a graph showing intensity of radiations as ordinates and Wave -lengths as abscissae;

Fig.y 6 illustrates culture plates showing the number of bacteria present inthe air with and without the radiation devices, said bacteria being obtained from the air within the region about eight feet from the patient and at the same level;

Fig. 7 is a chart showing composite post-opera.- tive temperatures of patients operated upon with and without the use of the radiation devices; and

Fig. 8 is a chart showing the time required for healing of the incisions of patients operated upon with and without the use of the radiation present and where it was absent.

Referring to Fig. 1 of the drawings, radiation devices lll are arranged in the form of a rectangular cluster 9 about a centrally-positioned illumination-furnishing source II, the cluster of radiation devices being positioned approximately seven feet above the floor upon which the operating table I2 stands. These radiation devices are mounted in a frame support sa, having elecmai contacts u for; engaging the end electrical contacts I5 of the radiation devices for the purpose oi' supplying energy from I asource, such as a transformer I6 to the radiation devices. There are two radiationA deviceselectrically connected in series on each side of thevcluster and these devices are arranged so that the uppermost device is disposed inwardly from the other and toward the illumination source l Il, whereby each pair lies in a diagonal plane forming one of the sides oa pyramid with a square base and a vertex directly above the light source Il, the devices do not shade one another in directing". the desired radiations diagonally downward toward an operating area immediately below said light source, so that they converge at a central vertex above the level of thev patient therebeneath. A transformer is provided for each two radiation devices. The frame support is suitably wired to carry electrical current from the transformer I6 to the electrical contacts I4 and is suspended from a trolley block il, the latter being mounted for movement on a rail IB. I

The position Aand arrangement ofv these radial The diameter of the glass tube is of importance since the current density of the discharge produced in the gaseous atmosphere within the tube I9 must be such that the proper intensity and character of radiations are emitted by the device so that the device operates with a temperature only a few degrees above room temperature.

The gaseous atmosphere is carefully selected and comprises'a very small quantity of mercury and a mixture 'of neon and argon in the proportion of 60' and 40% respectively, the pressure being -approximately 8 mm. of mercury. The current density is approximately ma. per square inch. Y

The radiations emitted by the device, as stated heretofore, must be of such intensity and wave length as to be lethal to bacteria and yet not harm the patient. It will thus be seen that the radiation generator, and particularly each device l0 thereof, vmay be considered as emitting a wedge of the ultra-violet radiations substantially restricted to a predetermined band, and of that the radiations are there weaker than at the heads of the operating team, whereby they are of insuiiicient intensity to be harmful, said radiations, however, being of a character and intensity to not only exert a bactericidal effect, but promote natural healing of the incised tissue. The operation4 is performed while the radiations are being generated and the relative positions of the participants maintained. During saidA operation, air-borne organisms exhaled by the operating` team enter what might be considered as the first zone, or that near the ultra-violet radiation generator, and are destroyed during their travel to what might be considered as the second zone, or that adjacent the patient,

before reaching the incision.

or'toward the shorter wave lengths. Those in .the longer wave length band, i. e., those above 2600 A. u. are ordinarily used for producing erythema with pigmentation and oedema,. It is to be noted with respect to the latter that the intensities of these longer or erythema radiations are relatively low compared'to the bactericidal radiations around 2500 A. u. and also that the radiations below 2500 A. u. are diminished in intensity as compared with those radiations around 2500 A. u.

Since the radiations above 2600 A. u. cause erythema with subsequentV pigmentation and oedema, it is obvious that since these are of relatively low intensity, very little harm can be expected in the way of irritating the tissue of the patient.- The radiations below 2500 A. u. also, when of suicient intensity, produce an erythema, but of different character. In the former the skin becomes darkened in color and blisters, whereas in the latter the skin becomes reddened. Too much of the former energy is harmful and may cause the skin to blister with possible disastrous results; hence the reason for diminishl ing the intensity of such radiations. At the same time, it is desirable to have a sufficiently high intensity of the shorter radiations which will be effective to destroy bacteria within approximately a foot of the radiation device, which, together with the radiations around 2500 A. u. will effectively destroy the bacteria emanating from the noses and throats of the operating team.

It is thus apparent that a zone of bactericidal radiations is created and maintained about the operating teams heads. Simultaneously with such action the radiations with wave lengths around 2500 A. u. which are not readily absorbed by the air, will be projected down to the zone or region around the patient to effectively destroy any bacteria coming within this region. The shorter radiations, namely, those around 2000 A. u. are easily absorbedby the air, hence these shorter radiations do not reach the patient with sufllcient intensity to bring about the destruction nique in operating may be altered with safety.

of the bacteria with sufllcient effectiveness in the period of time in which the operation is performed.

'I'he usual type ofV radiation sources now found on the market such, for example. as the carbon arc, mercury quartz burner, etc., have a spectral energy distribution of such a character that, in order to obtain suilicient intensity of the bactericidal radiation to effectively kill bacteria, too high an intensity of the longer wave lengths and -of the very short bactericidal radiations is ob- 4being employed. In the lower pair of plates of this figure the absence of such dots is plainly evident, and since this plate was expsed u me air when the radiation devices were functioning,

it is quite clear that the bacteria in the air were Referring to Fig. 5, there is illustrated theA destroyed, or their growth and multiplication inhibited.

These culture plates were'made with an ope ating team present and are,A therefore, truly representative of conditions as they actually exist.

The beneficial action upon the patient of the radiations emanating from these devices is depicted in Figs. 7 and 8. In Fig. '7 curve .A is a composite temperature curve of nine patients following operations without the use of radiation devices, while the curve B is a composite temperature curve of nine patients following the operations with the radiation devices functioning.

The benefit derived by the patient is quite evident since, in the lower graph the temperature was lower, there was less infection and less dis'- comfort to the patient. It is quite evident that `in the nine operations performed under the radiations the post-operative temperature curve is ,infection was detected and in other cases infection was present as indicated by the chart. It is quite evident that this period healing was considerably shortened with the devices operating, thus benefiting the patient. It was also observed that the incisions healed more rapidly in those cases where the operations were performed with the radiation devices in operation, the wounds healing per primum. Additionally.

there was no fluid from or sloughing of the inclsion, the incisions requiring no drains in the cases where the radiation devices were employed. Furthermore, all patients operated on under the radiation devices convalesced more rapidly with considerably less discomfort and pain. Because of this rapid and clean healing of the incisions, it has been found in performing such an operation known as thoracoplasty, that the usual tech- This new technique is the making of the second incision in the first incision instead of removed therefrom as has been the practice heretofore.

'I'hese remarkable results are attributable to the employment of the special radiation device arranged in such a manner as to create zones of radiations, in the one of' which the bactericidal radiations are particularly intensive and effective in destroying air-borne organisms where most needed, and in the other of which the bactericidal action of the radiations a-re still present but in which the accompanying radiations are so reduced in intensity as not to harm the patient.

Although the invention has been specifically described as relating to surgical operations, it is within the purview of the invention to contemplate all medlcal treatments where there is danger of infection from air-borne organisms or where beneficial action upon the patient is desired without any detrimental results occurring to the patient.

We claim:

1. An apparatus for preventing the infection of a patient by organisms transmitted by the air. while being operated upon or otherwise treated,

comprising in vcombination with an'operating ta- 'I ble'or other support, a cluster of radiation devices positioned above the tableor support at zone of bactericidal rays may be created'on and such a distance as to ood the patient and the operating team with bactericidal radiations, said devices having a radiation curve in which the intensity of the radiations of wave lengths around 2500 A. u.is predominant, as compared with the radiations on either side of said wave lengths and being arranged in pairs to denne a relatively large area, the devices of each pair defining one of diagonal planes forming the sides of a pyramid, thel vertex of which is centrally disposed above said cluster.

2. Irradiating apparatus for surgical use comprising a trolley block mounted for movement on a rail, a transformer carried by said block,

foursupporting elements depending from said block, with their intermediate portions braced witlrrespect to`one another, and their lower portions ared downwardly and outwardly, a rectangular frame each corner of which connects with one of said depending elements and each side of which carries a plurality of electrical contacts, radiation devices comprising elongated tubes extending generally parallel to the elements forming the rectangular frame, so as to outline the area enclosed thereby, and engaging said contacts, wiring between said contacts and transformer, whereby said radiation devices are operable therefrom, and a source of illumination supported from said trolley block and disposed in said rectangular area.

3. In an operating room, apparatus mounted for movement over an operating table, said apparatus comprising a movably mounted supporting element, a transformer carried thereby, supporting rods depending from said element, each of said rods extending downwardly' therefrom and Ithen flaring diagonallyl outward, a straight sided frame having each corner connectedto one of said rods, each side of said .frame carrying contacts, an elongated ultraviolet generator paralleling each side of the frame between said contacts, and means electrically connecting said contacts to said transformer.

4. Ultra-violet radiation generating apparatus adapted to be disposed above a patient and about six to eighteen inches above the heads of an operating team, said apparatus comprising a supporting element, rods depending therefrom, each of said rods having its lower portion flaring its corners connected to said rods, electrical contacts carried by said frame, a pair of ultraviolet -generators paralleling eachA side of said frame, and each comprising an elongated glass envelope adapted to efiiciently transmit ultraviolet light, said pairs lying in diagonal planes, which extend substantially parallel to the diagonally extending portions of the associated rods and merge at a central vertex thereabove, so as to, without interference, direct diagonal radiations on an operating area therebeneath, without danger of shadows from members of the operating team, each envelope yhaving a filling of neon, argon and mercury vapor at low pressure, said generators vbeing operable at such a potential around the patient, weaker on account of dispersion and air-absorption, but still effective to prevent wound infection and exert a beneficialv envelope adapted' to efficiently transmit ultradiagonally outward, a straight sided frame having that a discharge of'about one hundred and sixty `milliamperes per square inch occurs in each envelope, with the generation. of ultra-violet,-

" heads of the operating team to effectively kill nose, throat and other air-borne organisms above said patient during the operation, and another violet light, at least some of said discharge tubes being arranged, end to end, to define arelatively large normally horizontal area, and all lying in diagonal planes Amerging at a central vertex thereabove, so as to without interference direct .created above 'the patient around the heads of the operating team to eiectively kill nose, throat and other air-borne organisms above said patient V'during the'operation, and another zone of bactericidal radiations may be created on, and in the horizontal plane of, the patient, weaker on account of dispersion and air absorption, .but still effective to prevent wound infection and exert a beneficial action on healing. l

6. Ultra-violet radiation generating apparatus adapted tov be disposed above the h eads of an operating team and a correspondingly greater distance above a patient being operated on by said team, comprising a plurality of ultra-violet ray generators each consisting of a glass envelope adapted to eiiiciently transmit ultra-violet light, said generators lying in diagonal planes merging at a central vertex thereabove so as to direct diagonal radiations on an operating area therebeneath, each envelope having a rare gaseous filling admixed with mercury vapor at low pressure, and said generators being operable at such a potential that ultra-violet radiations predominantly in the band between 2500 and 2600 A. u. with some radiations of wavelengths below v 2500 A. u., are produced, whereby a zone of intense bactericidal rays is created adjacent the heads of the operating'team to effectively kill air-borne organisms exhaled by said team above said patient during the operation, and another -zone of bactericidal rays is created on and around the patient, weaker .on account of dispersion' and air absorption, but still effective to prevent wound infection and exert a beneficial action on healing.

7. Apparatus for supplying light and bactericidal radiations comprising a frame support, a plurality of elongated tubular ultra-violet light generating devices secured to thelower portion of said support, said devices being arranged to outline a relatively large area and disposed in pairs to define diagonal planes,l which planes merge at a central vertex thereabove, so as to without interference direct diagonal radiations on an operating area therebeneath without danger of shadows from members of an operating team. and an independent source of visible light disposed within said area.

8. Ultra-violet radiation generating apparatus adapted to be disposed above the heads of anv operating team, and at a correspondingly greaterV distance above a patient being operating on bvl said team', comprising a plurality of ultra-violet ray generators each consisting of a tubular glass envelope adapted to eiiiciently transmit ultraviolet light, said genera-tors outlining a relatively large area and arranged in pairs dening planes disposed so that the 'generators ofA said pairs direct radiations, withoutv interference, diagonally downward, so that said directed radiations -converge at a central vertex above the level of the patient therebeneath, each envelope having a rare gaseous filling admixed with mercury vapor at low pressure, and said generators being operable at such alpotential that ultra-violet radiations predominantly in the band between 2500 and 2600 A. u. are produced, whereby said converging radiations forma beam which eectively kills air-borne organisms exhaled by said team above said patient during the operation.

9. Ultra-violet radiations generating apparatus adapted to be disposed above the heads of an operating team and at a correspondingly greater distance above a patient being operated on by said team, comprising a plurality of ultra-violet ray generators, said generators being paired, each consisting of a tubular glass envelope adapted to efiiciently transmit ultra-violet light, said envelopes being positioned to deiine a relativelyl diations form a beam, which effectively kills airborne organisms tending to impinge on the wound of the patient during said operation.

' i n ROBERT F. JAMES.

DERYL HART.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2469412 *Mar 29, 1945May 10, 1949Carl B RoebkenTherapeutic lamp
US2609484 *May 10, 1949Sep 2, 1952Anciens Ets BarbierLighting of operating rooms
US2802094 *Jan 19, 1953Aug 6, 1957Richard T GroszPhotographic lighting assembly
US2965778 *May 15, 1958Dec 20, 1960Gen Electric Co LtdLow pressure electric discharge lamps
US3372272 *Dec 7, 1965Mar 5, 1968Donald R KorbLighting system for facilitating the diagnosis and treatment of eye disorders
US4196460 *Jul 14, 1978Apr 1, 1980Sybron CorporationMajor surgical light
US4414609 *Oct 8, 1982Nov 8, 1983Sylvan R. Shemitz And Associates, Inc.Luminaire for a visual display terminal
US4784135 *Aug 11, 1986Nov 15, 1988International Business Machines CorporationFar ultraviolet surgical and dental procedures
Classifications
U.S. Classification607/94, 313/642, 362/231, 362/804, 362/406, 362/33, 313/573
International ClassificationA61L2/10
Cooperative ClassificationY10S362/804, A61L2/10
European ClassificationA61L2/10