US3542030A - Laboratory stereotaxic equipment for small,living creatures - Google Patents

Description

United States Patent Inventors Roger A. Hoffman Box 84, Hamilton, 13346; Russel J. Reiter, 260 Crittenden Blvd., Rochester, New York 14620 '[211 AppLNo. 784,299 [22] Filed Dec.l6,1968 [45] Patented Nov. 24, 1970 [54] LABORATORY STEREOTAXIC EQUIPMENT FOR SMALL,LIVING CREATURES 6Claims,8Drawing Figs. [52] U.S.Cl. 128/303, 119/103 [51] Int. Cl. ..A6lb 17/00 [50] FieldofSearch 128/348, 303,303.], 133-, 134;119/96, 103

A [56] References Cited UNITED STATES PATENTS 3,250,252 5/1966 Leopold 119/103 FOREIGN PATENTS 907,977 10/1962 Great Britain 128/303 Primary Examiner-L. W. Trapp AttorneyDonald l-I. Sweet ABSTRACT: An experimental animal is immobilized by firm and mechanical contact with osseus structure, either direct or through intervening thin pectorial tissues. The contact means is a rigid structure, adjustable for clamping the animal ineffectively immobilized condition, at least with respect to the parts to be treated. The rigid clamping structure also provides guide means for guiding the insertion of conventional cannula or other treatment member to the exact point of treatment. In case of a cannula, a hollow, rigid guide member adapted to receive the cannula in sliding engagement is.provided, and stop means for determining the exact extent of insertion of the cannula. The complete assembly is adapted for repeated use without disturbing the adjustment of any of the stereotaxic contact members, but certain of the members are independently removable to permit the removal of a treated animal and the installation of an untreated animal. Calibrated indicating means are provided for all adjustments that affect the position and orientation of the parts or places to be operated, or otherwise treated, and a record of all calibration readings enables an unskilled person to duplicate any set of predetermined recorded adjustments without repeating the original difficult determination.

v, Patented Nov. 24,1970 3,542,030

Sheet 013 I F/ G. 4 1246 42-10 TK/GEM/IJL IVEIVE F/aa [I 1H 1 3%16? it u LABORATORY STEREOTAXICEQUIPMENT F SMALL, LIVING CREATURES v In the accompanying drawings: FIG. 1 is a diagrammatic plan viewof the skeletal structure of a rodent skull, indicating the points of-contact for immobilizing it;

FIG.- 2 is a partial anatomical sketch as on line 2-2 of FIG.

FIG. '3 indicates the same anatomical parts as FIG. 2 before operating; I I

FIG. 4 is a left side view of the mechanical equipment of no.5,

' FIG. Sis a plan view of the same equipment; J

FIG. 6 is a partial. rear endview of the same equipment; FIG. 7 is a detail section through the cannula and syringe, indicating the adjustment means for limiting the depth of insertion; and i i 1 FIG. 8 is an enlarged detail in planview of the swivel mounting for an earbar.- I

In the embodiment of 'the invention selected for illustration, the table 10 carries three supporting assemblies. A fixed post 12 supports'a left side .earbarassembly. and a standard 16 is slideable on the table and fastened in adjusted position by conventional means, such as threaded hold down bolt 18 extending down through a slot 20 in the table 10 to'pull a clamping block 22 up' against the table. This standard supports the nosebar assembly 24.

f PRIM RvsuPPoRT The primary support for the-skull is a left earbar 28 and a right earbar'3'0, entering the ear canals of the specimen (See FIG. 1). Thesepress firmly against the thin pectorial membrane 32 See F16 2 which is reinforced by the skull bone 34 behind it. The taperof the bars is suchthat a limited amount of rotation oftheskull canstill occur, about a'transverse axis approximately indicated by a dottedline at 36 inFIG. 1. The pituitary gland is indicated at 38. The skull 26, on the scale drawn in -1 of the drawings, is greatlyenlarged and the gland 38,.is avery tiny thing, especially with small animals. v

In the drawing, the. top of'theskull has been cut away to remove the bony structure and expose the pituitary'gland 38. In performing such an operation as removal, or treatmentof this gland, thetask of merely locating it accurately in space and finding it there, without, removing part of the skull, is a major problem.

' TI-IEEAR B AR S would impair the operation materially, and it is difficult for an ordinary human hand and fingers to adjust the position of an object grasped by the fingers by such tiny increments.

The pivot 40 carries a segmental. ear 44 (See FIG. 7). A manual actuator head 46'is mounted in the block 12-8 to rotate on a vertical axis. The pinion 48 meshes with the teeth of the sector 44. The relative diameters of the gears involved may be such that a lineardisplacement of the cannula tip corresponds to a linear displacement many times gnarled outer surface of the actuator 46.

The natural instincts of the operator are best served by arranging the transmission so that when the hand reaches under the nut 46 and rotates it counterclockwise the pivot 40 will rotate in the same rotary sense. The interposition of the idler 50 accomplishes this result.

Means are provided for clamping the pivot 40 firmly in position. The clamping nut 48 has'threaded connection with the pivot 40 to engage the block portion 12-12 between the nut and the enlargement 40-2 lying in the window 12-16.

Means are provided for indicating the orientation of the earbar and observing it and recording it with the same order of precision as the control of its movement. The long indicator pointerSl (See FIG. 3) extends back over the side block'l2-8 to the remote end of the block and the block carries a calibrated arcuate scale 52.

The corresponding supporting and adjustment equipment for the earbar 30 duplicates that for the earbar 28 exceptthat it is reversed from left to right. In most operations it is desired that the angularity of the earbars 28 and 30 should be identical on opposite sides and accordingly the calibrations on the indicators 52 are arranged with numbers increasing toward the longitudinal median plane of the equipment.

THE NOSEBARS The earbars 28 and 30 extend in a horizontal plane and are pivoted on vertical-axes, and in most animals of the type in- I a is so small precision adjustment in a vertical direction is'essenshaped transverse'groove which has sliding'engagernent with thespacer bar 1 2-2 carrying-calibrations 12-4 to register with a zero mark12-6 on the post. The left side block 12-8 is a'rigid unit with the crossbar 12-2 .but is made of plastic material. It is a two piece construction with an upper half 12-10 and a lower half 12-12 and the-two halves are fastened together by conventional fastenings 12-14 at three places. Each half is cut away to complete the definition of a transverse window 12-16.

.The earbar 28 is conventionally anchoredin a vertical pivot head 40 (See FIG. 3), as by flattening the sidesof the pivot and clamping itagainst a'flarige 28-2 by a fastening nut 28-4. The earbar is'threaded to engage the clamping nut 28-4and bar and nut both have alined axial bores. for receiving a conventional cannula 42. An adjustable stop 44 fastened by an Allan screw 46 comes into abutment with the face of the nut 28-4 to determine'the'limit of penetration of the cannula with precision, during repeated-operations on successive animals.

Means are provided for rotating the earbar and cannula and clamping them in precisely adjusted orientation. As clearly indicated in FIG. 2, the relative sizes of the cannula and the gland to be removed or' treated are such that a relative displacement greater than perhaps two thousandths of an inch tial to reliable operation. Thelstandard 16 carries a slideable intermediate support 60 for an upper cross bar 62 and a lower cross bar 64. In FIG. 5 the crossbar 62 is shown carried at the end of a rotary arm 66 integral .with a pivot 68 extending through the carriage 60, and the entirety can be clamped in adjusted position as by the wing nut 70.

As best indicated in FIG. I, the lower nosebar 64 is posi-- on the top of the nose of the specimen. Both these bars, when clamped by their wing nuts constitute a rigid unit with the carriage 70 and means are provided for adjusting the vertical 2 position of the carriage with precision. We have indicated an actuator 74 on a rotary shaft 76 carryinga pinion 78 meshing with a rack 80 on the carriage 60. The precise adjustment may be read on the calibrated annulus 82 cooperating with a zero line at 84 on the standard 16. Thus after the earbars have been finally fixed in position for the specimen, it is possible to raise or lower the specimens to rotate the entire skull by two degrees or so about the transverse axis 36 and get the pituitary 38 precisely level with the earbars as indicated in FIGS. l and 2. In actual practice it may or may not always be necessary to cutaway the skull of the first specimen and achieve direct inspection of the tip of the cannula. When the animal to be treated is not materially dissimilar to some other previous specimen for which readings have already been determined, experienced personnel may succeed in getting a perfect adjustment without such additional effort.

greater for the In any event, after experienced personnel have secured satisfactory results on one specimen, and the settings are of record, lateral withdrawal of one of the blocks will withdraw the earbars from the treated specimen and an untreated specimen may be laid in place and clamped by return of the earbars to the previous position. In this way an indefinite number of specimens can be given any specific treatment desired by relatively inexperienced personnel, because the single stereotaxic adjustment will serve for all of a large batch of substantially identical specimens. Also, thereafter, whenever an additional lot of specimens substantially indentical to the previous lot needs to be processed, the equipment may have been adjusted for the treatment of some other animal, but it can readily be put back in the proper adjustment so that a single stereotaxic determination enables inexperienced personnel to treat a substantially unlimited number of approximately identical specimens.

Reference to FIGS. 2 and 3 will indicate that the process does involve substantial destruction of at least on eardrum and perhaps both, but most of the uses for which such specimens are intended are not impaired by this. Also, in the types of animals commonly processed, the animals seem to be capable of some sort of auditory sensation within a short time after undergoing the treatment described.

Where the objective is to remove the pituitary the cannula, in the position of FIG. 2 is rotated about its axis to break up the gland into pieces which can be withdrawn by suction, but it will be obvious that others .may readily adapt the invention for use under various conditions of service by employing one or more of the novel features disclosed, or equivalents thereof.

For instance, medication, or replacement of the pituitary gland appear to be within the ambit of the equipment disclosed.

We claim:

1. Mechanical stereotaxic equipment for positioning and immobilizing the head of an anesthetized animal, such as a specimen of laboratory rat, and for operating on the interior structure of said specimen as for removal of the pituitary gland, or otherwise treating aninterior organ or gland, or the space normally occupied thereby, comprising, in operative combination: i

A. spaced parallel blocks of a size to lie beside the skull and body of said specimen; each block having a transverse through window near its front end and adapted to be substantially at one adjacent ear of said specimen; an earbar assembly associated with each block and comprising an earbar proper, and a vertical pintle rigid therewith; said earbar passing through said window toward the vertical median plane of said specimen; said pintle being positioned in said window and journaled in said block; adjustable support means for approximating said blocks toward each other, with said specimen between them, to enter said earbars in the ear canals of said specimen and support the skull with limited freedom of rotation about a transverse horizontal axis determined by the contacts of said earbars with the walls of said canals; clamping means for clamping said blocks in adjusted position, and indicator means including calibrations for use in recording the adjustment;

B. front end clamping means including a lower transverse nosebar positioned to lie under the upper jaw of said specimen, in contact with both sides of said lower jaw, and limit downward movement of said skull at each contact; an upper transverse nosebar positioned to lie above and in contact with the nose to the rear of said lower nosebar and limit upward movement at said upper contact; said three contacts defining a plane in which the two lower contacts press up and the one upper contact presses down; whereby small adjustments may 'flex the neck of the specimen and adjust the specimen with the point of treatment within the specimen at a predetermined position or status; C. supporting means for said nosebars comprising a standard, offset laterally from the longitudinal vertical median plane of said specimen and slideable parallel to said median plane; a carriage vertically slideable on said standard; and a mounting for each nosebar on said carriage for adjusting the position of said nosebar; whereby movement of said carriage changes the height of both nosebars in unison; and subsequent adjustment of said mountings makes individual changes of one or both nosebars; independent manual means for clamping said post and carriage and each nosebar in adjusted position, and calibrated indicating means for each adjustment; and

D. independent manual means for rotating said earbar around its pivot, and clamping it in adjusted position, and calibrated indicating means for each earbar adjustment.

2. Equipment according to claim I in which said last-mentioned adjustment includes a manual actuator; and a reducing transmission from said actuator to said pintle; whereby increments of change in orientation of said earbar smaller than the human hand could conveniently make with adequate precision can be accurately made.

3. Equipment according to claim 2- in which the calibrated indicating means for said earbar orientation includes a long radial-arm carried by said pivot, and precision calibrated indicating means adjacent the remote end of said radial arm; said remote end lying close above the block on the same side and extending from the pivot to the rear end of the block.

4. Equipment according to claim 1 in which one of said earbars has an open axial bore to receive the cannula of a conventional syringe projecting through said earbar and beyond the inner end thereof to the exact situs of the part to be operated.

5. Equipment according to claim 1 in combination with a unitary tablelike support for each block and for said nosebar supporting means.

6. Equipment'according to claim 5 in which all said adjustment means is positioned to leave an unoccupied hemisphere above and around said specimen for free access to said specimen.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 542 ,030 November 24 Roger A. Hoffman et al.

It is certified that error appears in the above identifie patent and that said Letters Patent are hereby corrected as shown below:

In the cover page ABSTRACT: lines 4 and S "ineffectiw should read in effectively Column 1 line 23 after "assembly" insert a fixed post 14 supports a right side ea] assembly, line 26, "as threaded" should read as a threz Column 2, line 6, after "meshes with" insert a nylon i: pinion 50 which meshes with line 70, "cutaway" should rea cut away Column 3, line 19, "on" should read one Column 4, line 1, "said canals" should read said ear canal:

Signed and sealed this 30th day of March 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E SCHUYLEI Attesting Officer Commissioner of Pa1

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