Apparatus for homogenizing and handling biowaste and other materials in isolation

Apparatus to receive fecal material directly into a container and maintain it isolated, particularly as to its odors, while automatically homogenizing and withdrawing samples as may be desired and disposing of the remainder. The apparatus, either in fixed or portable form, includes connections to a source of homogenization fluid, a source of cleansing water, and a drain. It also includes means to mix the fecal material vigorously with the homogenization fluid to achieve a substantially homogeneous mixture which can be disposed of with relative ease and which can be sampled into a vacutainer through a vacutainer needle attached liquid-tight to the chamber containing the mixture. For multiple sampling, an automatically operated vacutainer changer brings one vacutainer at a time into position to have a sample of the mixture injected into it. Following such sampling, the apparatus and needle are automatically washed.

FIELD OF THE INVENTION 
This invention relates to apparatus and a method for receiving a chemical 
sample that is either inherently obnoxious, such as fecal matter, or for 
other reasons is hazardous or difficult to homogenize prior to its 
analysis. In particular, the invention relates to apparatus for receiving 
such samples in a restricted chamber, homogenizing the samples with a 
suitable liquid, and withdrawing measured aliquots of the homogenized 
material into closed individual containers containing, if necessary, 
suitable reagents for further analysis. 
BACKGROUND OF THE INVENTION 
No one who has lived through the experience will question the fact that the 
analysis of fecal samples is one of the most unpleasant tasks performed in 
a medical diagnostic laboratory. The offensive nature of the sample, 
combined with the inadequacy of the sampling techniques and methods 
available--none of which has been specifically designed to deal with fecal 
matter--have resulted in considerable neglect of this important area of 
clinical analysis. 
Chapter 107 of Gradwohl's Clinical Laboratory Methods and Diagnosis, 7th 
ed., 1970, (one of the standard reference books) relates to the analysis 
of fecal samples and starts out as follows: "The examination of the feces, 
although generally stressed by clinical teachers as an important means of 
diagnosis in medical and surgical cases, is seldom thoroughly performed. . 
. most physicians are not adequately utilizing this type of examination". 
It then goes on to say: "The indifference to the possibilities of help 
from routine stool examinations, lack of concise information as to 
technique and interpretation, and esthetic objection to handling the 
material, all have contributed to this field of laboratory work being 
neglected by most workers and students. . .we believe much more emphasis 
must be placed on this subject". 
The development of a suitable automatic apparatus for the collection, 
homogenization and sampling of feces would remove the esthetic objections 
alluded to above and permit the performance of a number of tests of 
obvious diagnostic and/or prognostic value. Besides, the determinations 
would be made quantitative (rather than qualitative or semi-quantitative 
as they are now) and readily automatable using autoanalyzers already in 
existence. 
Examples of clinically important determinations that would be greatly 
facilitated are: 
(1) Quantitative (24 hour) determination of electrolyte losses in feces. 
Included here are such ion as Na.sup.+ K.sup.+, Mg.sup.++, Ca.sup.++, P, 
and Cl.sup.-. A better knowledge of the amount of fecal electrolyte losses 
can contribute greatly to the proper management of patients with acute or 
chronic diarrhea. 
(2) Quantitative determination of fecal fat. This seldom-utilized procedure 
tests the ability of the gastrointestinal track to digest and absorb the 
fat contained in a test meal. It reflects pancreatic function as well as 
intestinal function. The use of radioactively labeled fats added to the 
test meal greatly simplifies the methodology required. 
(3) Tests of intestinal absorption. One example is the determination of 
nitrogen content as a measure of digestion and absorption of protein. 
Fecal nitrogens are an essential part of nitrogen balance studies. 
(4) Quantitative determination of blood losses. 
(5) Determination of fecal pH. 
(6) Coprocultures. There is much to be gained by the study of the "normal" 
flora of the intestine and its variations in response to alterations in 
diet composition, orally administered drugs, etc. 
(7) Determination of fiber content of the feces. This is receiving 
increasing attention lately since it relates to the pathogenesis of 
syndromes as common as constipation and diverticulosis as well as 
carcinoma of the colon which is now the second most common cause of 
cancer-related deaths among American males. 
(8) Quantitative determination of fecal sterols. The fecal route is the 
most important one for the elimination of cholesterol and its derivatives 
(bile acids and breakdown products thereof), and improved testing has 
obvious significance in the management of patients with coronary heart 
disease. 
(9) Determination of enzyme activities in feces. Two kinds of enzymatic 
activities are of interest: one is the group of digestive exzymes that 
have been measured in feces for quite some time and are of value as tests 
of pancreatic and intestinal function. The other kind is non-digestive 
enzymes not normally present in feces but which would appear as a 
consequence of cell-rupture of the intestinal lining--whatever the cause. 
It is anticipated that these assays should provide good indicators of the 
presence and extent of inflammatory disease of the G.I. tract. The 
determination of enzymes of bacterial origin is being actively developed 
and promises to become a valuable tool in determining the presence of 
microorganisms difficult to cultivate. 
(10) Presence of carcinogens and/or other hazardous compounds. Carcinogens 
derived from tobacco smoke are swallowed and must eventually appear in 
feces unless absorbed or degraded in transit. Similarly a number of other 
hazardous materials contaminating the intestinal environment (industrial 
air and water pollutants, by-products of the metabolism of intestinal 
microflora, etc.) should be detectable in feces presumably before 
permanent damage is inflected. 
There are may other analyses that should be possible if suitable apparatus 
were available to receive and handle the samples in isolation so as to 
overcome reluctance by laboratory personnel to carry out existing tests 
and develop new tests. 
OBJECT AND SUMMARY OF THE INVENTION 
It is one of the objects of this invention to provide apparatus to receive 
and to homogenize in a limited environment fecal and other noxious 
material to be analyzed and means to transfer samples of the homogenized 
material into closed containers for further analysis. 
Another object of the invention is to provide a receptacle for biowaste 
products and to homogenize them in the receptacle while withdrawing 
through a separate channel any air that enters the receptacle and is 
contaminated by odors therein. 
A further object is to provide a biowaste receptacle capable of operating 
as a portable unit to be placed at the bedside of patients in order to 
receive waste products from such patients without requiring the patient to 
go to a fixed location, the receptacle being arranged to homogenize the 
waste and transfer samples thereof to closed containers while either 
sealing off the homogenization chamber or arranging circulation of the 
homogenate to prevent it from leaving the receptacle and, simultaneously, 
providing for the withdrawal of odors to prevent their contaminating the 
atmosphere. 
In accordance with this invention a sample receptacle is provided that 
includes a chamber to receive material to be analyzed, particularly 
biowaste material, and especially fecal matter. The chamber includes an 
inlet for liquid, usually water, to homogenize the sample. The receptacle 
further includes means to inject the homogenate into a closed container, 
such as a vacutainer, which is an evacuated test tube provided with a 
resealable cap of rubber or the like through which the homogenate can be 
injected by a suitable hollow needle that has a side opening and a 
spring-biased slidable closure. After the needle has pierced the cap of 
the vacutainer, the homogenate enters the vacutainer by the differential 
pressure that results from having ambient atmospheric pressure on the 
homogenate and low pressure inside the vacutainer. If the homogenate is 
enclosed within a sealed chamber, the apparatus includes means to reduce 
the volume of the chamber, for example by a piston of controlled stroke in 
the wall of the chamber, to compensate for the quantity of material 
transferred to the vacutainer. 
The apparatus further includes means to separate the needle and the 
vacutainer after a proper quantity of homogenate has been transferred. The 
rubber stopper of the vacutainer automatically reseals itself and the 
vacutainer can be removed to an analytical lab subsequent analysis. The 
apparatus includes means for bringing several vacutainers one after 
another into position to receive homogenate from the same batch. 
After sufficient homogenate has been withdrawn from the homogenizing 
chamber, the apparatus includes means to wash the chamber and direct the 
remaining homogenate and the washing fluid out through a drain. The drain 
need not be of large size in view of the fact that the process of 
homogenization has reduced the original sample to particles of very small 
size. If the homogenizing chamber is of the type that is entirely closed 
during the homogenizing process, it can remain closed during the process 
of washing it out, and any aerosols produced can be carried down the 
drain. In the case of apparatus having an open homogenizing chamber 
dependent for containment of the sample during homogenization on the 
contour of the walls of the chamber and the control of circulation of the 
homogenate, aerosols may be extracted by vents relatively high on the wall 
of the bowl above the homogenizing chamber. Such vents are connected to an 
exhaust fan and the aerosols are forced out through a vent pipe 
sufficiently long and isolated to carry them away from any area where they 
would be objectionable. 
The open-topped homogenizing chamber makes the apparatus (minus the 
vacutainer changer-sampler mechanism) suitable for use as a toilet in 
areas where water is scarce. Homogenization of fecal matter allows it to 
pass through a smaller drain than is usually required, and the wash water 
and homogenizing water required total less than the usual replacement 
water for a toilet bowl and tank. Also the procedure should be quieter 
than is usually the case in an ordinary toilet. The operating cycle for 
removing material from the chamber and washing the chamber can be timed 
differently in the case of solid waste than for entirely liquid waste, 
thereby effecting additional savings in the case of liquid waste, which 
would only require a small amount of wash water.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The apparatus shown in FIG. 1 includes a bowl 11 divided into a main 
section 12 to accommodate solid fecal waste and a smaller section 13 to 
accommodate liquid waste. The latter section has an outlet 14 which, in 
use, would be connected to a drain pipe or an appropriate receptacle. 
The bowl 11 is atop an enclosure 16 in which a homogenization chamber 17 is 
located. The homogenization chamber is directly under an opening 18 at the 
bottom of the section 12. At certain times of the operating cycle a 
sliding lid 19 having an opening 21 therein is moved either into the 
position shown, in which the opening 21 is concentric with the opening 18, 
or is moved to the left to a position in which the solid portion 22 of the 
lid covers the upper open part of the chamber 17 and completely isolates 
that chamber from the section 12 of the bowl 11. The lid 19 is slid back 
and forth between its two positions by a handle 23. 
The bottom of the lid 19 rests on a plate 26 that has an opening 27. The 
bottom of the lid is in good contact with at least the edge portion of 
this plate that defines the perimeter of the upper opening of the chamber 
17. This is desirable to prevent any of the sample from being attached to 
the surface of the section 22 of the lid 19 and transferred into a space 
between the section 22 and the plate 26. 
The main wall 28 of the homogenization chamber 17 is generally cylindrical 
in shape and defines a frusto-conical lower portion 29 of the chamber 17. 
The lower end of the wall 28 rests on a support comprising a plate 31 and 
vertical members 32 and 33. A homogenization motor 34 is supported on the 
plate 31 and the shaft 35 of the motor extends through a liquid-tight 
opening in the plate 31. This structure includes stirring blades 36 and 37 
located in the frusto-conical recess 29. The end of an inlet through which 
homogenization fluid enters the chamber 17 is indicated by reference 
numeral 38. Wash water is fed into the chamber 17 by way of a pipe 39, a 
valve 41, and inlet opening 42 into which the end of the pipe 39 is 
inserted. Unneeded sample material and water that has been used for 
washing the homogenization chamber 17 leave the chamber by way of an 
outlet 43 and an outlet pipe 44 with a valve 46 controlling the flow 
through the pipe 44. 
The removal of aliquot samples of the homogenized material from the chamber 
17 is by way of a vactuainer needle 47 that has an opening, which is not 
visible in FIG. 1, in its side wall. The opening is covered by a sliding 
cover 49 that is biased by a spring 51 compressed between a recessed part 
of the wall 28 and the sliding cover 49. Two vacutainers 52 and 53 are 
shown supported in aligned holders 54 and 55. As will be described 
hereinafter, a motor 56 steps the holders 54 and 55 in one direction to 
bring each vacutainer 52 and 53 into alignment with the needle 47. A 
pressure plate 57 engages one end of the vacutainer aligned with the 
needle 47. In the view in FIG. 1 this happens to be the vacutainer 52. 
When this vacutainer is pressed to the right in the direction indicated by 
the arrow 58, the needle 47, which may be smaller and sharper than is 
illustrated, pierces the rubber stopper 59 that closes the end of the 
vacutainer 52. A piston 61 is shown extending through the main wall 28 of 
the chamber 17 directly opposite the needle 47. However, such alignment is 
not necessary. The piston need only enter the chamber 17 at any point far 
enough to shift the proper volume into the vacutainer. To do so, the 
piston is controlled to move axially in response to operation of a motor 
62. 
The operation of the apparatus in FIG. 1 begins with the reception of solid 
fecal matter which passes through the main section 12 of the bowl 11 and 
the openings 18, 21 and 27 into the homogenization chamber 17. 
Homogenizing liquid is then allowed to enter the inlet 38 in sufficient 
quantity to fill the chamber 17 completely up to the level of the lower 
surface of the lid 19. During this step the valves 41 and 46 are both 
closed. Thereafter the lid 19 is closed be moving the handle 23 to the 
right. This movement of the lid 19 completely seals off the upper end of 
the chamber 17. The homogenization process is carried out by turning on 
the motor 34 to rotate the blades 36 and mix up the solid matter and the 
homogenizing liquid thoroughly. The motor is allowed to rotate for several 
minutes and the time may be controlled by a timer to keep the motor 
running long enough to effect thorough homogenization of the matter in the 
chamber 17. 
After the homogenization is complete, the pressure plate 57 pushes to the 
right the vacutainer 52 shown aligned with the needle 47. As the needle 
pierces the rubber stopper 59 on the vacutainer, the stopper pushes on the 
sliding cover 49 to uncover the hole in the side of the needle. The needle 
itself remains fixed and only the cover slides to the right against the 
pressure of the spring 51. While the vacutainer may have a reduced 
internal pressure which would tend to draw the homogenate through the 
needle 47, the fact that the homogenization chamber 17 is entirely closed 
prevents this from happening. Instead, the piston is moved to the left a 
certain distance by means of the motor 62 to displace an aliquot measure 
of the homogenate into the vacutainer 52. Then the vacutainer is withdrawn 
to the left by means that will be discussed hereinafter, and the cover 49 
slides back over the hole in the needle. The piston 61 does not move back 
to the right but remains in its displaced position until the next 
vacutainer, for example the vacutainer 53, is moved into position to be 
pushed against the needle 47. When the needle pierces the cover of the 
vacutainer 53 sufficiently to expose the hole in the needle to the 
interior of the vacutainer, the motor 62 drives the piston 61 forward 
another predetermined amount of transfer another aliquot measure of the 
homogenate into the vacutainer 53. 
After a sufficient number of vacutainers have thus received homogenate, the 
outlet valve 46 is opened and the inlet valve 41 for the wash water is 
also opened to allow wash water to enter the chamber 17. The motor 34 may 
be energized to operate at its top speed to circulate the wash water in 
the chamber 17 and to allow it to flow out through the pipe 44, The motor 
62 may be reversed to draw the piston back into its recessed position. 
Finally, to drain the chamber 17, the lid 19 may be opened to allow all of 
the wash water to flow out through the valve 46 and the pipe 44. At such 
time it is normally desirable to close the valve 41 on the inlet side of 
the system to prevent excess wash water from flowing into the chamber 17 
and interfering with the outflow of the remaining homogenate. The process 
of introducing clean water into the chamber 17, circulating it to stir up 
any remaining homogenate and allowing the water and homogenate to flow out 
may be repeated as many times as necessary to clean completely the 
interior of the chamber 17. Thereafter, the apparatus is ready to be used 
by another patient. 
Completely closing the chamber 17 while the homogenizing process is being 
carried out not only has the advantage of containing any aerosols that 
result from the process of the sample, but it also allows a fixed quantity 
of fluid to enter the chamber in order to carry out the homogenization 
process. As a result the assays can be referred back to a known total 
volume so that the results will be quantitative rather than qualitative. 
Moreover, the identity of content from one sample to the next of a single 
quantity in the chamber 13 can be maintained by keeping the motor 34 
operating at a relatively slow mixing speed while the samples are being 
transferred to the vacutainers. 
The holders 54 and 55 that support the vacutainers 52 and 53 in FIG. 1 are 
part of a turret-like structure shown in detail in FIGS. 2-4. FIG. 4 in 
particular shows that turret structure 63 more clearly than the other 
figures. The turret comprises the two holders 54 and 55 rigidly aligned to 
rotate as a unit on a central rod 64. The holders 54 and 55 are notched 
discs, each of which has, in this embodiment, eight recesses 66-73, each 
of the proper size to hold a vacutainer, although only the two vacutainers 
52 and 53 are shown, and these are in the recesses 66 and 72. The 
direction of rotation of the turret 63 is counterclockwise, as indicated 
by the arrows 74, and is accomplished by apparatus that will be described 
in connection with other figures. 
The turret 63 shown in FIG. 4 is located in an open-topped box 76. Empty 
vacutainers will be fed by gravity from a magazine-like container. At the 
time depicted in FIG. 4 the uppermost recess happens to be the recess 72 
in which the vacutainer 53 has been placed. As this uppermost recess 
rotates to the position of the recess 73, any vacutainer resting in it 
would remain in place simply by the force of gravity. However, at the 
third position, the recess 66 occupied by vacutainer 52, additional means 
are placed alongside the recess to hold the vacutainer in place. The 
additional means are associated with pushing the vacutainer into position 
so that its self-sealing rubber stopper 59 can be pierced by the needle 
47, and this part of the apparatus will also be described in connection 
with other figures. 
As the turret 63 moves still another step, to the position of the recess 
67, any vacutainer in that position would fall out, except for the fact 
that a flange 77 extending upwardly from a base 78 curves around the 
turret 63 to support any vacutainer in the position of the recess 67. 
At the next step of the turret, any vacutainer in the position defined by 
the recess 68 would be directly over an exit slot 79 defined between the 
curved flange 77 and a second, vertical flange 81. Vacutainers 82-84 that 
have fallen through the slot 79 land on a sloping support 86 of suitably 
soft material and roll safely to rest at the lower end against a low wall 
87. The vacutainer 82 is depicted in broken lines to indicate that it is 
in motion from the turret 63 to the support 86. Vacutainers 83 and 84 are 
shown partially filled with homogenate from the chamber 17 and may also 
contain a suitable reagent to test the solid matter for any of the ions or 
chemicals that might be contained therein. In any event, the material to 
be tested will have reached the vacutainers without having to be handled 
by laboratory personnel. Furthermore, the vacutainers 83 and 84 can be 
transferred to other apparatus while still keeping the homogenized 
material enclosed. 
The mechanism for pushing each vacutainer axially into engagement with the 
needle 47 is best shown in FIGS. 2 and 3. In particular, in FIG. 2 a 
regular motor 88 operating through a speed-reducing gear box 89 rotates a 
shaft 91 on which are mounted a turreet actuator disc 92 with an actuator 
member 93 projecting therefrom. Because of the speed reducing provided by 
the gear box 89, a relatively high speed motor 88 may be used instead of 
the low speed motor 56 in FIG. 1. This actuator member 93 engages each of 
a series of pins 94 extending from the turret mechanism, which, as shown 
in greater detail here than in FIG. 4, includes a short, thick cylinder 
96, the two members 54 and 55, and the central shaft 64 on which the two 
members 54 and 55 are rigidly mounted. 
The shaft 91 also engages a cam mechanism comprising a first cam 98 and a 
second cam 99. The layout of these cams is best shown in FIG. 3. The cam 
98 engages a roller-follower 101 attached to a bar 102, and the cam 99 
engages a roller-follower 103 that is also attached to the bar 102. The 
configurations of cams 98 and 99 are such that the follower 101 pushes the 
bar 102 to the right and the follower 103 pulls the bar 102 to the left. 
These are the two motions required to push a vacutainer, for example, the 
vacutainer 52, into engagement with the needle 47 and to retract it from 
such engagement. 
The bar 102 has two members 104 and 106 rigidly connected to it and 
connected, in turn, to a member 107 that has two bent ends to grasp the 
vacutainer 52 between them. One of these bent ends was identified in 
connection with FIG. 1 as the pressure plate 57. The length of the member 
107 is such that its other bent end 105 is adjacent the stopper 59 of the 
vacutainer. The end 105 thus enables the member 107 to retract the 
vacutainer 52 away from the needle 47 after the vacutainer has received 
liquid or homogenate through the needle. 
The bent end 105 may extend over only a part of the stopper 59 so as not to 
prevent the needle 47 from piercing the stopper 59 when movement of the 
member 107 and its bent pusher end 57 force the stopper against the 
needle. Alternatively, and as shown in the present embodiment, the bent 
end 105 may have a central opening through which the needle 47 pierces the 
resealable stopper 59. The central opening in the bent end 105 is also 
large enough to allow the sliding, resiliently biased cover that normally 
extends over the opening 48 in the side of the needle 47 to be forced to 
retract only when it engages the stopper 59. This prevents the opening 48 
from being uncovered before it has entered the stopper 59, which is 
important to prevent leakage of the homogenate outside the stopper. 
Furthermore, the resiliently biased cover can either be a sleeve 49 biased 
by a spring 51, as shown, or a close-fitting tubing of rubber or the like 
around the needle 47. Each vacutainer is brought into position between the 
members 57 and 105 by rotation of the turret 63 when the bar 102 is in its 
retracted position farthest to the left. The members 104 and 106 slide 
linearly on two rigidly mounted guide rods 108 and 109 that prevent the 
members 104 and 106 from turning on the bar 102. In addition, the bar may 
be square or rectangular to assist in holding the members 104 and 106 
correctly positioned. 
The turret mechanism also includes a detent mechanism, which is most 
clearly shown in FIG. 2. This includes a detent pin 111 slidably mounted 
in two plates 112 and 113 at the end of box 76 housing the vacutainer 
actuating structure. The plate 113 is rigidly mounted in the box 76 
parallel to the plate 112 to support one end of the turret shaft 64. The 
detent pin has a collar 114 rigidly mounted on it and a spring 116 that 
presses against the collar 114 and against the plate 112 to urge the 
collar against the plate 113 and thereby to urge the pin 111 into limited 
engagement with the member 54. By means of the detent mechanism, and 
suitably located detent depressions, each at a fixed position relative to 
each of the recesses 66-73, the rotation of the turret 63 and the members 
54 and 55 can easily be locked at each step so that each vacutainer in 
turn will be brought specifically into alignment with the needle 47. These 
depressions are identified in FIG. 4 by the reference numbers 66a-73a 
corresponding to the recesses 66-73 with which they are aligned. 
FIGS. 2 and 3 show a convenient location for the piston 61. As previously 
stated, this piston need not be directly opposite the needle 47 since the 
only purpose of the piston is to decrease the volume of the chamber 17 by 
a specific amount corresponding to the amount of sample transferred to 
each vacutainer in turn. This reduction in the volume of the chamber 17 
could be accomplished by mounting the piston 61 at any point in the 
chamber wall. 
FIGS. 5 and 6 show an alternative embodiment of the invention to carry out 
the same functions as the embodiment in FIGS. 1-4. The uppermost part of 
the structure in FIGS. 5 and 6 is a bowl 117 having a shape similar to a 
standard toilet bowl. The upper edge of the bowl 117 is formed as an 
in-turned and down-turned rim 118 that extends over a pair of channels 119 
and 121. The channel 119 is generally closed except for spaced holes 122 
and is connected by way of a solenoid inlet valve 123 to a water supply 
pipe 124. The channel 121 has a U-shaped cross section along its length 
and is connected by way of a homogenization fluid solenoid valve 126 to a 
pipe 127 to a source of the homogenization fluid, which may be water. 
The lower part of the bowl 117 terminates in a homogenization chamber 128 
defined by a wall 129 and connected by way of a restricted opening 131 to 
the lowermost part of the bowl 117. A fluid level sensor 132 is located in 
the wall 129 at a predetermined level above the level of the needle 47 to 
measure the proper level of the homogenization fluid. A water-tight gland 
133 centrally located in the lower part of the chamber 128 allows a shaft 
134 to rotate therein without permitting any liquid to leak back along the 
shaft. A set of homogenization blades 136 is attached to the end of the 
shaft 134 to be rotated thereby. The ends of the blades 136 are twisted in 
a manner similar to a propeller to force fluid in the homogenization 
chamber 128 to follow a generally toroidal path virtually entirely within 
the chamber 128 as indicated by arrows 137 and 138. The other end of the 
shaft 134 is connected by a positive drive pulley 139 and a 
correspondingly shaped driving belt 141 to drive pulley 142 mounted on a 
shaft 143 of a homogenizer motor 144. 
An outlet pipe 146 is connected to one part of the lowermost section of the 
wall 129 and a discharge solenoid valve 147 in this pipe controls the 
discharge of material from the chamber 128. The flow of discharged 
material is effected by a pump 148 to provide positive transfer of outlet 
fluid from the pipe 146 to a drain 149. 
The pump 148 is driven by a motor 151 that also drives a centrifugal fan 
152. This fan is connected by a pipe 153 to a manifold 154 that has 
several intake openings 156 spaced around the bowl 117 above the 
constricted opening 131 at the top of the homogenization chamber 128. The 
upper part of each of the openings 156 is covered by a flap 157 to allow 
air to enter the openings 156 primarily from below. Air can be drawn into 
the openings 156 and on out the vent pipe 158 by the fan 152 after the air 
enters the upper part of the bowl 117. The flow will be such that this air 
will circulate down to the lower part of the bowl and will pick up any 
aerosols emanating from the chamber 128. This effectively seals 
objectionable odors in the chamber 128 to make this embodiment as 
acceptable as the embodiment in FIG. 1. The flaps 157 also prevent any 
liquid entering the bowl 117 by way of the water supply pipe 124 or the 
homogenization fluid pipe 127 or any other source from flowing into the 
ventilating system. 
The motor 88, including the gear mechanism 89 and the vacutainer changing 
disc 92 along with the cams 98 and 99 shown mounted on the enclosure 76 in 
FIG. 5 are the same as shown in FIGS. 1-4. These drive components for 
filling the vacutainer 52 through the needle 47 in FIG. 6 operate exactly 
as described in connection with the embodiment in FIGS. 1-4 except that 
since the homogenization chamber 128 has no lid similar to the lid 19 of 
the chamber 17 in FIG. 1, it is not necessary to provide a piston similar 
to the piston 61 in FIG. 1 to control the quantity of homogenate 
transferred to one of the vacutainers 52. 
The bowl 117, the motors 144 and 151, the vacutainer changer and filler 
mechanism in the enclosure 76 and all of the other components connected 
therewith are supported on a platform 159 that has an enclosed chamber 161 
within which the pulleys 139 and 142, the belt 141, the outlet pipe 146 
and the solenoid valve 147 are located. On top of the platform 159 is 
another enclosure 162 that encloses all of the other mechanism associated 
with the bowl 117 and the various motors and valves and pipes. A 
programmed timer 163 is also located within the enclosure 162 and is 
connected to control the sequential operations of the various motors and 
valves. 
FIG. 7 shows the electrical circuit for the programmed timer 163. This 
circuit includes a pushbutton starting switch 164 connected in series with 
the fan and centrifugal pump motor 151 between two wires 165 and 166 of a 
standard 110 v AC line. The latching coil 167a of a latching relay 167 is 
electrically connected directly in parallel with the motor 151 and in 
series with the pushbutton switch 164. The latching relay includes an 
unlatching coil 167b and a movable contact 167c that is caused to engage a 
fixed contact 167d when the relay is in its latched condition. The 
contacts 167c and 167d are connected directly in parallel with the 
pushbutton switch 164. 
The pushbutton switch 164 is also connected to a movable contact 168c of a 
second latching relay 168. This relay has a latching coil 168a and an 
unlatching coil 168b. It also has two fixed contacts 168d and 168e to be 
contacted by the movable contact 168c, depending on whether the relay is 
unlatched or latched. The contact 168d is connected in series with the 
homogenization fluid solenoid valve 126. 
The volume sensor 132 is connected through a standard sensor electronic 
circuit 169 to control the opening and closing of a pair of contacts 169a 
and 169b. These contacts are closed when the volume of the water in the 
chamber 128 shown in FIG. 6 is sufficient to actuate the sensor 132. 
Closing of the contacts 169a and 169b connects the latching coil 168a in a 
series circuit with the contacts 167c and 167d between the two wires 165 
and 166 of the 110 v line, thereby attracting the contact 168c into 
engagement with the fixed contact 168e. 
The contact 168e is connected to the arm 171c of a 5-position, 2-layer 
stepping relay 171. The relay 171 has a stepping coil 171a and a resetting 
coil 171b. The arm 171c is mechanically connected to another arm 171d. The 
first position marked "0" of the terminals engaged by the arm 171c is 
connected to one terminal of a timer motor 172, the other terminal of 
which is connected to the AC wire 166. This timer motor is mechanically 
connected to a multi-cam timer 173, each cam of which engages at least one 
movable arm to control the opening and closing of at least one switch 
connected to that arm. The timer 173 in this embodiment has seven cams 
173a-173g. 
The sampler motor 88 that controls rotation of the turret 63 which was 
described particularly in connection with FIG. 2 in which the vacutainers 
are held and also controls the axial movement of the vacutainers into 
engagement with the needle 47 and away from it, is electrically connected 
between one of the AC wires 166 and a fixed contact 174a of a switch 174. 
This switch has a movable contact 174b controlled by a roller-follower 
174c that engages the surface of the cam 173b to bring the contacts 174a 
and 174b together each time the follower is lifted by one of the raised 
portions of the cam 173b. 
The sampler motor 88 also drives two cams 176 and 177. A switch 178 has a 
fixed contact 178a and a movable contact 178b connected to a cam-follower 
178c to be controlled by the cam 176. One of the contacts of the switch 
178 is connected to the AC wire 165, and the other contact of the switch 
178 is connected to one terminal of the motor 88 and is also connected to 
all but the first of the five position contacts of the set engaged by the 
arm 171c. Another switch 179 is controlled by the cam 177 driven by the 
sampler motor 88. The switch 179 has a fixed contact 179a and a movable 
contact 179b attached to a cam-follower 179c that engages the cam 177. One 
end of the stepping coil 171a of the stepping relay 171 is connected 
directly to one of the AC wires 166 and the other end of the coil 171a is 
connected through a switch 180 to one of the contacts of the switch 179, 
the other contact of which is connected to the other AC wire 165. The 
latter end of the coil 171a is also connected through a switch 181 to the 
AC wire 165. The switch 181 includes a fixed contact 181a and a movable 
contact 181b controlled by a cam-follower 181c that rides on the surface 
of the cam 173e. The switch 180 includes a fixed contact 180a and a 
movable contact 180b controlled by a cam-follower 180c that rides on the 
surface of the cam 173g. 
One end of the resetting coil 171b of the stepping relay 171 is connected 
to the AC wire 166 and the other end of the coil 171b is connected to the 
arm 171d of the five-position stepping switch on the second layer of the 
relay 171. The first position, marked "0", engaged by the arm 171d is not 
connected to any other circuit part, but the second through fifth 
terminals engaged by the arm 171d and labeled, respectively, "1, 2, 3, 4" 
are connected to correspondingly marked terminals "1, 2, 3, 4" of a 
manually controlled switch 182. This switch has an arm 182a connected to 
one AC wire 165. 
A switch 183 is connected in series between one terminal of the unlatching 
coil 167b of the latching relay 167 and the AC wire 166. This switch 
includes a fixed contact 183a and a movable contact 183b attached to a 
cam-follower 183c to be controlled by the cam 173a. The switch terminal 
183a connected to one end of the coil 167b is also connected to one end of 
the unlatching coil 168b of the relay 168. 
The discharge solenoid valve 147 shown in FIGS. 5 and 6 is shown in FIG. 7 
to be electrically connected in series with a switch 184 between the two 
AC wires 165 and 166. The switch 184 includes a fixed contact 184a and a 
movable contact 184b attached to a cam-follower 184c controlled by the cam 
173c. In a similar manner the wash solenoid valve 123 is connected in 
series with a switch 186 between the two AC wires 165 and 166. This switch 
includes a fixed contact 186a and a movable contact 186b mechanically 
connected to a cam-follower 186c to be controlled by the cam 173d. The 
homogenization motor 144 is also connected in series with a switch 187 
between the two AC wires 165 and 166. This switch 187 includes a fixed 
contact 187a and a movable contact 187b mechanically attached to a 
cam-follower 187c to be controlled by the cam 173f. 
The operation of the apparatus in FIGS. 5 and 6 as controlled by the 
circuit in FIG. 7 starts with actuation of the pushbutton switch 164 to 
complete the circuit to energize the fan and centrifugal pump motor 151 
and to latch the relay 167. This closes the contacts 167c and 167d to keep 
the fan and pump motor 151 operating even after pressure on the pushbutton 
switch 164 is released. 
The homogenization fluid solenoid valve 126 is also actuated at the same 
time that the relay 167 is latched. The actuation of the homogenization 
fluid solenoid valve is by way of the movable contact 168c of the 
unlatched relay 168 and the fixed contact 168d connected to the valve 126. 
This allows fluid to enter the homogenization chamber 128 by way of the 
valve 126 until the fluid rises to a level that actuates the sensor 132. 
This controls the electronic circuit 169 to close the contacts 169a and 
169b, thereby latching the relay 168 and moving the arm 168c away from the 
contact 168d to cut off energizing current to the homogenization fluid 
solenoid valve 126. 
When the contact 168c responds to the latching of the relay 168, it moves 
into contact with the fixed terminal 168e and thus, by way of the arm 171c 
of the stepping relay 171 and the "0" terminal of that relay, it starts 
the timer motor 172. As the timer motor 172 rotates the cams 173a-173g 
clockwise, the homogenization motor cam 173f forces the cam-follower 187c 
to close the contact 187b against the contact 187a and thereby energize 
the homogenizer motor 144. The homogenizer motor cam 173f keeps the switch 
187 closed for a relatively long time and at the end of this time the cams 
have rotated sufficiently to cause the stepping relay pulse cam 173e to 
close the switch 181 and thereby energize the stepping coil 171a to move 
the arms 171c and 171d one step in the clockwise direction to their 
respective terminals marked "1". This brings the arm 171c into position to 
start the sampler motor 88 through a circuit that includes the arm 171c, 
the fixed terminal 168e of the relay 168, the movable arm 168c, and the 
contacts 167c and 167d of the latching relay 167. 
Energization of the sampler motor 88 causes the cams 176 and 177 to start 
rotating in a clockwise direction, thereby releasing the cam-follower 178c 
to close the contacts of the switch 178 and to keep the sampler motor 
running. The stepping relay pulse cam causes the contacts of the switch 
181 to remain closed for only a short time so that the stepping pulse is 
relatively short. This actuation of the stepping coil 171a moves both of 
the arms 171c and 171d from their respective "0" positions to their 
respective "1" positions. As a result, current to the timer motor 172 is 
interrupted and the cams 173a-173g are stopped. The cam 173f stops in a 
position that keeps the homogenizer motor 144 operating during the 
following sampling process and until the motor 172 starts to rotate again. 
The sampling process controlled by the sampler motor 88 moves the 
vacutainers into engagement with the needle 47 one at a time, retracts 
them, and rotates the turret 63 another step to repeat the process. As the 
sample motor 88 rotates, the cam 176 briefly opens the switch 178, but the 
sampler motor is still energized through the switch arm 171c. The cam 177 
briefly closes the switch 179 just before the brief opening and reclosing 
of the switch 178 and thereby delivers a short stepping pulse to the 
stepping coil 171a to move the arms 171c and 171d to their "2" contact. 
The switch arm 182a is set to allow samples to be obtained in three 
vacutainers and so is placed on its "3" contact. As a result, when the 
sampler motor makes its third rotation in connection with transferring a 
sample to the third vacutainer, the resetting coil 171b of the stepping 
relay 171 causes the arms 171c and 171d to return to their "0" positions. 
This allows the timer motor 172 to be energized again by way of the arm 
171c. 
As the timer motor 172 again starts to rotate, it rotates the cams 
173a-173g and turns off the homogenizer motor 144 by allowing the contacts 
of the switch 187 to open. Shortly after that the cam 173c causes the 
discharge valve 147 to open and allow the remainder of the homogenate to 
be drawn out by the pump 148 and sent through the drain pipe 149. The fan 
and centrifugal pump motor 151 remains operating during the entire cycle. 
After the discharge valve 147 has been opened for the first time, the cam 
173c allows the switch 184 to reopen and to de-energize the valve 147. 
Then the cam 173d closes the contacts of the switch 186 and energizes the 
wash solenoid valve 123 to allow clean water to flow down the bowl and 
into the homogenization chamber 128. While this water is in the chamber, 
the cam 173f again closes the switch 187 to energize the homogenization 
motor 144 a second time. Thereafter the homogenizer motor is turned off by 
the effect of the cam 173f in reopening the switch 187, and the discharge 
solenoid valve is again energized as the cam 173c closes the switch 184 
for a second time. During the time that this valve is open, the cleansing 
wash water is drawn through the centrifugal pump 148 and expelled through 
the drain. 
The continued rotation of the cams 173 causes the cam 173d to close the 
switch 186 a second time and open the wash solenoid valve 123 to allow a 
new quantity of rinsing water to wash down the bowl and enter the chamber 
128. The cam 173f closes the switch 187 during the time and energizes the 
homogenizer motor 144 to stir up the wash water. The sampler motor cam 
173b then closes the switch 174 for a brief interval pulsing the sampler 
motor 88 into operation. The sampler motor runs for a complete cycle of 
sampling of one vacutainer. This provides the first wash of the inside of 
the sampling needle 47 as shown in FIG. 6. The wash water in this case 
goes into an extra vacutainer inserted into the members 54 and 55 solely 
for the purpose of receiving the water that washes the needle. 
At the same time that the switch 174 is closed, the cam 173g opens the 
switch 180 and holds it open until the end of the operating sequence. This 
prevents current pulses from flowing through the switch 179 to the 
stepping coil 171a and causing the arms 171c and 171d to step forward 
until a new sequence has started. 
At the end of the cycle of operation of the sampler motor 88 when the first 
washing of the needle takes place, as has just been described, the opening 
of the switch 178 stops the motor 88. By that time the timer motor 172 
will have driven the cams 173 past the point at which the cam 173b can 
close the switch 174. Continued rotation of the motor 172 causes the cam 
173c to close the switch 184 again to open the discharge valve 147 and 
allow water in the chamber 128 to flow out the drain 149. The discharge 
valve 147 closes again when the cam 173c rotates farther and allows the 
switch 184 to open. 
A second needle-washing cycle is then carried out in a manner similar to 
the first such cycle. That is, continued rotation of the cams 173 by the 
timer motor 172 causes the cam 173d to close the switch 186 and energize 
the wash solenoid valve 123. This permits a new quantity of water to flow 
into the chamber 128. The cam 173f then closes the switch 187 to start the 
homogenizer motor 144 again. The cam 173b then closes the switch 174 
briefly again to supply another pulse to operate the sampler motor 88 for 
another cycle. The water for the second cleansing of the needle will go 
into still another vacutainer placed in a recess in the holders 54 and 55 
for that purpose. 
At the completion of rotation of the sampler motor 88 following the second 
needle washing cycle, the cam 173c again closes the switch 184 to open the 
discharge valve 147 and allow the remaining water to flow out the drain 
149. The final event of a complete testing sequence occurs when the cam 
173a closes the switch 183 and thereby completes the circuits through the 
unlatching coils 167b and 168b to release both of the latched relays 167 
and 168 to turn off the entire circuit. 
A typical time for homogenizing a fecal sample, transferring the homogenate 
to five vacutainers, and completing the automatic cleansing of the 
apparatus is approximately three or four minutes. During the entire 
procedure, the sample will be isolated from the hospital personnel, from 
the time of sample collection through the final steps of analysis. 
The apparatus as embodied in either FIG. 1 or FIGS. 5 and 6 can be operated 
as a portable toilet with suitable connections to vents, drains, water 
lines, and power lines, or it can be placed in a fixed location, in which 
case the connections can be of a more permanent nature. 
While the open-topped chamber 128 in the embodiment in FIGS. 5 and 6 does 
not provide quite as rigid control of the volume as the container 17 with 
its lid 22 in FIG. 1, the difference in accuracy of measurement of the 
total homogenization volume is not significant. The results are still well 
within the range of accuracy necessary to constitute quantitative analysis 
of the sample. The most significant difference in this regard between the 
embodiment in FIG. 1 and that in FIGS. 5 and 6 is that the piston 61 can 
be used only in the embodiment in which the container is sealed 
liquid-tight by the lid 22. Use of the piston allows more accurate control 
of the quantity of homogenate allowed to enter the vacutainers. 
Under certain circumstances it may be required to control the speed of the 
homogenizer motor 34 in FIG. 1 or the homogeizer motor 144 in FIGS. 5 and 
6. This can be done by means of a standard silicon-controlled rectifier 
circuit arranged to cause the motor speed control circuit to vary, for 
example, from a high initial homogenization speed to a lower stirring 
speed to keep the mixture stirred up during the sampling process. 
While this invention has been described in terms of specific apparatus, it 
will be understood that modification may be made therein and that the true 
scope of the invention is determined by the following claims.