Filter assembly device for use in surgical aspirated suction

A filter assembly for elective use in conjunction with a surgical evacuation system is provided which includes a filter housing having a head portion and a body portion with a through passageway extending therebetween defining a filter receiving chamber. The head portion is connectable to an aspirator tip and the body portion is connectable to a flexible suction conduit. A filter element is disposed within the filter receiving chamber of the filter housing. The filter element includes a head member having a fluid flow passageway extending therethrough, a fluid impermeable base member spatially disposed from the head member and a fluid permeable body member disposed between the head member and the base member. The head member has a diameter greater than the base so that a portion of the head member extends outwardly from the body portion of the filter housing to enhance removal of the filter element and a second portion of the head member forms a substantially fluid-tight seal with the body portion of the filter housing.

BACKGROUND AND SUMMARY OF THE INVENTION 
This invention relates to a filtering assembly, and more particularly but 
not by way of limitation, to a filter assembly for the collection of 
aspirated tissue or materials during surgical procedures. 
A standard adjunct to all modern surgical procedures is the use of suction 
pump aspirating systems. The almost immediate removal of human or 
introduced fluids from the surgical site by use of an aspirator tip, 
tubing and suction pump provides the clinician vastly improved visibility 
and dexterity throughout the treatment procedure. One inherent 
disadvantage to a suction pump aspirating system is the inability to 
retrieve, collect or save fine human or foreign materials once captured at 
the aspirating end. 
An important function of the present invention is to permit the clinician 
to easily introduce a fine filter assembly into the aspirator line of a 
suction pump aspirating system to preclude the loss of valuable materials, 
tissue or information. Valuable materials, such as precious dental alloys, 
may also be collected and recycled; and human tissues may be collected for 
medical biopsy purposes. 
Another use of the present invention is for autologous transfer of 
collected human tissue to another needed or more desirable site. Critical 
information may be gathered by the use of the filter assembly of the 
invention. Use of the filter assembly will immediately visually verify if 
certain undesirable pathological or foreign bodies have been successfully 
and completely removed. These might include detached tooth root tips, 
metal particles from a wound injury, or cystic membrane walls. Also 
verifiable would be the accidental, inadvertent removal of healthy human 
tissue. The use of the filter assembly of the present invention in 
collecting diagnostic data will in some cases eliminate or reduce the 
necessity of patient exposure to additional diagnostic radiation. 
Likewise, the knowledge gained may preclude unnecessary exploratory tissue 
trauma. 
Yet another clinical application of the filter assembly of the present 
invention is the quick, verifiable retrieval of mechanical components 
utilized in surgical procedures. The possibility of contracting or 
introducing vital or bacterial infections has almost universally mandated 
the use of surgical gloves in all medical fields during the past ten 
years. A major disadvantage of glove use is the reduction of tactile 
sensation. Dental/medical devices of minute dimensions are now routinely 
used in bone fixation, dental implantology, endontics, tooth pin and post 
reconstruction to mention only a few. Metal screws, pins and posts may 
become loose in the surgical opening or oral cavity. By use of the filter 
assembly of the present invention, such components may be quickly 
extracted by the suction device. The filter verifies complete retrieval. 
Additionally, such items as broken surgical drills or other mechanical or 
human debris may be verifiably removed by use of the filter assembly of 
the present invention. When captured and retrieved, visual verification 
will be certain and almost instantaneous. The necessity of additional 
exploratory probing trauma, diagnostic testing or radiographic examination 
become unnecessary. 
In accordance with the present invention, a filter assembly for elective 
use in conjunction with a surgical evacuation system (i.e., an aspirator 
tip, a flexible suction conduit and a suction pump) is provided which 
comprises a filter housing having a head portion and a body portion. The 
head portion is characterized as having a first end, a second end and a 
through passageway extending therebetween and the first end of the head 
portion is connectable to the aspirator tip so that fluid communication is 
provided between the aspirator tip and the passageway extending through 
the head portion. A portion of the passageway in the second end of the 
head portion of the filter housing defines a first chamber. 
The body portion of the filter housing is also characterized as having a 
first end, a second end and a through passageway extending therebetween. 
The second end portion of the body portion is connectable to the flexible 
suction conduit and a portion of the passageway in the first end of the 
body portion defines a second chamber such that when the first end of the 
body portion is slidably disposed in the second end of the head portion, 
the first and second chambers in the head portion and the body portion 
cooperate to define a filter receiving chamber. 
A removable, elongated mesh filter element is disposed within the filter 
receiving chamber. The filter element comprises a head member having a 
fluid flow passageway extending therethrough, a fluid impermeable base 
member spatially disposed from the head member and a fluid permeable mesh 
body member extending between the head member and the base member. The 
head member is provided with a diameter greater than the base member so 
that when the filter element is disposed within the filter receiving 
chamber, a first portion of the head member extends outwardly from the 
second chamber of the body portion of the filter element so as to enhance 
removal of the filter element and a second portion of the head member 
extends into the second chamber of the body portion so that a fluid-tight 
seal is formed therebetween. Thus, the fluid mesh permeable body member of 
the filter element provides a collection chamber for aspirated tissue and 
materials during surgical procedures. 
In one aspect, the elongated filter element of the filter assembly of the 
present invention is further provided with reinforcing members extending 
between the head member and the base member of the filter element so as to 
enhance the rigidity of the fluid permeable mesh body member of the filter 
element and thereby enhance insertion and removal of the filter element 
from the filter receiving chamber defined by the filter housing. 
An object of the present invention is to provide a filter assembly which 
may be readily inserted and removed from an evacuation system between an 
aspirator and a suction line of a suction pump aspirating system. 
Another object of the present invention is to provide a filter assembly for 
use in a suction pump aspirating assembly which permits easy and rapid 
disassembly for removal of the filter from the filter assembly. 
Still another object of the invention is to provide a filter assembly for 
use in a suction pump aspirating assembly which is economical to 
manufacture, versatile in use and which can be readily cleaned and 
sterilized.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
Referring now to the drawings, and more particularly to FIGS. 1 and 2, 
shown therein is a filter assembly 10 constructed in accordance with the 
present invention for use in conjunction with a surgical evacuation system 
which comprises an aspirator tip 12, a suction conduit 14 and a suction 
pump 16. The filter assembly 10 may be machined from a variety of metals 
or autoclavable plastics or injection molded of autoclavable plastics. The 
design may also vary in size to accommodate any surgical situation from 
minute craniofacial surgical applications to veterinary large animal 
surgical applications. Further, as will be described in more detail 
hereinafter, the filter assembly 10 can be readily disassembled for 
thorough cleaning and sterilization. 
The filter assembly 10 is provided with a filter housing 18 having a head 
portion 20 and a body portion 22. A second or lower end 24 of the head 
portion 20 frictionally receives a first or upper end 26 of the body 
portion 22 so as to define a filter receiving chamber 28 (FIG. 2) 
therebetween. An aspirator accepting opening 30 openly communicates with 
the filter receiving chamber 28 and a filter chamber exit opening 32 of 
the filter housing 18 so that fluid flow is provided through the filter 
receiving chamber 28 when the head portion 20 and the body portion 22 of 
the filter housing 18 are in a connected position as illustrated in FIGS. 
1 and 2. 
As more clearly shown in FIG. 1, the head portion 20 of the filter housing 
18 is provided with a peripheral area 34 of enlarged diameter to enhance 
gripping of the head portion 20 of the filter housing 18 during either 
securing of the head portion 20 to the body portion 22 or removal of the 
head portion 20 from the body portion 22. The peripheral area 34 of 
enlarged diameter is desirably tactily enhanced with multiple serrations 
or machine knurl patterns to enhance the purchase of the head portion 20 
and to promote ease of use during surgical aspiration. 
The filter housing 18 can be manufactured from any acceptable machined 
metals or from surgically approved plastic materials. Further, the size of 
the filter housing 18 can vary widely. However, desirable results have 
been obtained wherein the filter housing 18 is approximately 1 inch in 
diameter and approximate 4 inches long. It should be understood that by 
utilizing the same or similar designs, other sizes can be manufactured to 
accept different sizes of filters, the size of the filter housing 18 
depending upon whether the surgical requirements are minute, craniofacial 
surgeries or veterinary large animal applications. 
Referring more specifically to FIGS. 2 and 3, the head portion 20 of the 
filter housing 18 is characterized as having a first or upper end 36, the 
second or lower end 24, and a through passageway 38 extending 
therebetween. The first end 36 of the head portion 20 is connectable to 
the aspirator tip 12 such that fluid communication is provided between the 
aspirator tip 12 and the passageway 38 extending through the head portion 
20. 
The body portion 22 of the filter housing 18 is also characterized as 
having the first end 26, a second end 40, and a through passageway 42 
extending therebetween. The upper end 26 of the body portion 22 of the 
filter housing 18 defines a shoulder step 44 which mates into a 
counterbore 46 of the head portion 20 of the filter housing 18 so as to 
provide a sliding sealed fit therebetween. The union of the head portion 
20 to the body portion 22 of the filter housing 18 can be further 
facilitated by the use of a "O" ring 48 disposed in a recess formed about 
the external surface of the body portion 22 of the filter housing 18 near 
the first end 26 thereof substantially as shown so that a fluid-tight seal 
is formed between the head portion 20 and the body portion 22. 
Once the head portion 20 is mated with the body portion 22, a through 
chamber opening is formed through the filter housing 18, the aspirator 
accepting opening 30, and the passageway 38 in the head portion 20, the 
passageway 42 at the filter chamber exit opening 32 in the body portion 
20. 
As more clearly shown in FIG. 2, the aspirator tip 12 is provided with an 
aspirator fitting 50 whose outside diameter is slightly smaller than the 
aspirator accepting opening 30 in the first end 36 of the head portion 20. 
The aspirator fitting 50 can be disposed in a locked sealed position 
inside the aspirator accepting opening 30 and retained therein by an 
internally disposed "O" ring 52 substantially as shown whereby a 
substantially fluid-tight seal is formed between the head portion 20 of 
the filter housing 18 and the aspirator tip 12 via the aspirator fitting 
50 and the "O" ring 52. The filter housing 18 is now conjoined and ready 
for use with or without a filter element 54 in place. 
Referring now to FIGS. 2-4, the filter element 54 which is disposable 
within the filter receiving chamber 28 of the filter housing 18 is a 
substantially rigid, elongated element comprising an enlarged head member 
56 having a fluid flow passageway 58 extending therethrough, a fluid 
impermeable base member 60 spatially disposed from the head member 56 and 
a substantially tubular-shaped fluid permeable body member 62 disposed 
between the head member 56 and the base member 60. The fluid flow 
passageway 58 extending through the head member 56 is provided with an 
internal diameter at least equal to an internal diameter of the aspirator 
accepting opening 30 in the first end 36 of the head portion 20 of the 
filter housing 18. Desirably, the fluid permeable body member 62 of the 
filter element 54 is fabricated of a substantially rigid mesh material 
fabricated from metal, polymeric materials or combinations thereof. The 
mesh size of the mesh material used in the fabrication of the fluid 
permeable body member 62 of the filter element 54 can vary depending on 
the desired use of the filter assembly 10. 
The head member 56 is provided with a sufficient height such that when the 
filter element 54 is disposed in the filter receiving chamber 28 of the 
filter housing 18, a first portion 64 of the head member 56 extends 
outwardly from the filter receiving chamber 28 defined by the body portion 
22 of the filter housing 18 so as to enhance removal of the filter element 
54. A second portion 66 of the head member 56 extends into portion of the 
filter receiving chamber 28 defined by the body portion 22 so that a 
fluid-tight seal is formed therebetween which permits the fluid permeable 
body member 62 of the filter element 54 to function as a collection 
chamber for aspirated tissue and materials during surgical procedures. 
To enhance the rigidity of the fluid permeable body member 62, the filter 
element 54 further comprises reinforcing members 68 and 70 which extend 
between the head member 56 and the base member 60 of the filter element 
54. The reinforcing members 68 and 70 enhance the rigidity of the fluid 
permeable body member 62 of the filter element 54 and enhance insertion of 
the filter element 54 into the filter receiving chamber 28 defined by the 
filter housing 18, as well as removal of the filter element 54 therefrom. 
To enhance a substantially fluid-tight seal between the head member 56 of 
the filter element 54 and the first end 26 of the body portion 22 of the 
filter housing 18, the first end 26 of the filter housing 18 extending 
about the passageway 42 is flared or beveled outwardly; and the lower 
surface of the second portion 66 of the head member 56 is beveled. Thus, 
when the filter element 54 is slidingly disposed in the filter receiving 
chamber 28 of the body portion 22 of the filter housing 18, the beveled 
portion of the head member 56 engages the flared portion of the body 
portion 22 to provide an effective seal therebetween. That is, the filter 
receiving chamber 28 has an inside diameter which is slightly larger than 
the diameter across the longitudinal filter reinforcing arms 68, 70 and 
fluid permeable body member 62 of the filter element 54, but smaller that 
the head member 56 of the filter element 54. However, the filter receiving 
chamber 28 is provided with a counterbore 72 at the junction of the head 
portion 20 and the body portion 22 which is slightly larger than the head 
member 56 substantially as shown in FIGS. 2 and 3, but tapers to provide 
the beveled surface. This unique feature enables an effective seal to be 
formed about the head member 56 of the filter element 54 and the body 
portion 22 of the filter housing 18 while at the same time permitting a 
portion of the head member 56 to extend upwardly therefrom when the filter 
element 54 is seated in the filter receiving chamber 28. As previously 
stated, by having the portion of the head member 56 exposed, placement of 
the filter element 54 is enhanced as well as removal of the filter element 
54 by permitting sure and firm purchase of the head member 56 of the 
filter element 54 when the head portion 20 of the filter housing 18 is 
disconnected from the body portion 22. 
The filter housing 18 may be utilized without the filter element 54 as a 
convenient handle adjunct for the aspirator tip 12 and the flexible 
suction conduit 14, or, as preferred, the filter element 54 will be 
disposed within the filter receiving chamber 28 defined by the head 
portion 20 and the body portion 22 of the filter housing 18. It should be 
noted that, in the event the filter housing 18 is employed initially 
without the filter element 54 in place, if at any point during the 
surgical procedure when the use of the filter element 54 is required or 
anticipated, it may be quickly and easily introduced in the following 
manner: The head portion 20 of the filter housing 18 is separated from the 
body portion 22 by a twisting, sliding motion to reveal the filter 
receiving chamber 28. The head member 56 of the filter element 54 is 
purchased by a thumb and forefinger or some surgical grasping instrument. 
The filter element 54 is then slid easily into the filter receiving 
chamber 28 whose diameter is slightly larger than the diameter across the 
base member 60, the fluid permeable body member 62 and the longitudinal 
reinforcing members 68, 70 of the filter element 54, but smaller than the 
head member 56 of the filter element 54. The counterbore 72 at the 
entrance of the filter receiving chamber 28 is slightly larger than the 
head member 56 of the filter element 54 and is configured to accept the 
head member 56 and secure same in a stable position. It is critical and 
unique to the present invention that the first portion 64 of the head 
member 56 be exposed when the filter element 54 seats completely in the 
filter receiving chamber 28. The advantages of having the first portion 64 
of the head member 56 of the filter element 54 exposed enhances removal of 
the filter element 54 by sure and firm purchase, whereas, when the filter 
element 54 is in position within the filter receiving chamber 28 of the 
filter housing 18, fluids and particulate matter unrestrictedly pass 
through the filter element 54 so that unwanted fluids can exit through the 
fluid permeable body member 62 of the filter element 54 while valuable 
human tissues, pathological tissues for analysis, precious metals, and the 
like are captured within the fluid permeable body member 62. Further, 
because the body portion 22 of the filter housing 18 allows for certain, 
external purchase of the head member 56 for retrieval of the filter 
element 54, the possibility of spillage and loss of the materials sought 
to be collected in the filter element 54 is substantially eliminated. 
Thus, once the filter element 54 is removed from the filter receiving 
chamber 28, the enclosed materials may be transferred to a suitable 
receptacle and the filter element 54 may then be reinserted, a replacement 
filter element 54 be inserted, or the procedure reinitiated without the 
use of the filter element 54, at the discretion of the clinician. As can 
be seen in FIGS. 2 and 3, when the filter element 54 is completely seated 
in the filter receiving chamber 28 of the body portion 22 of the filter 
housing 18, the filter element 54 becomes totally captured by the head 
seating flat of the head portion 20 of the filter housing 18, the 
counterbore 72 and the filter receiving chamber 28 of the body portion 22 
of the filter housing 18. 
While the filter housing 18 and the filter element 54 are illustrated as 
having a circular configuration, it should be understood that the filter 
housing 18 and the filter element 54 can be of any variety of geometric 
shapes, such as oval, circular with longitudinal flats, squares and the 
like. 
Changes may be made in the construction and the operation of the various 
parts, elements and assemblies described herein and the steps or the 
sequence of steps of the methods described herein without departing from 
the spirit and the scope of the invention as defined in the following 
claims.