Electronic calculator - register for hematology differentials

An electronic tabulator for computing and displaying running totals of six different cells as well as a running total of the combined cell count. Means are also provided for dividing the individual cell count by the total cell count to express the individual cell counts as a percentage of the total. In a preferred embodiment, a keyboard provides data entry to seven commercially available calculator chips which compute the running totals and individual percentages as well as provide an output to individual LED displays.

BACKGROUND OF THE INVENTION 
The present invention relates to an electronic instrument for counting and 
totalizing a plurality of different types of blood cells or other 
biological cells and expressing the individual cell counts as a percentage 
of the total count. 
Differential cell counts are an important aspect of testing in medical and 
other biological laboratories. A white blood cell differential is one of 
the most commonly performed counts. Other differential counts include 
maturation index in PAP smears, leukocyte alkaline phophatase, and barr 
body counts. 
The apparatus currently employed by laboratories for computing 
hematological differantials and other cell counts are mechanical counters 
or electrically operated mechanical step counters. These range from very 
simple counters which are capable of providing running totals of two types 
of cells to counters which are capable of totalizing nine different types 
of cells as well as a total of all cells counted. In order to express the 
individual cell counts as percentages of the total, which is the most 
commonly used method for rendering a meaningful expression of the cell 
counts, is to terminate the count when the total of all cells counted 
reaches 100. At this point, the individual percentages are equal to the 
total count expressed for each of the cell types. A problem which often 
arises, however, is that the technician may not stop when the total count 
reaches 100 thereby necessitating manual computation to determine the 
percentage value for each type of cell. This is a time consuming operation 
and often causes technical errors. This may result in an erroneous cell 
differential leading to an incorrect diagnosis on the part of the 
physician utilizing the laboratory data. 
A further disadvantage to the necessity for terminating the count at 100 
cells or ten factor multiples thereof is that it may be desirable for all 
the cells on a certain slide to be counted. In this case, it is imperative 
that the percentage calculation be made. 
The mechanical counters are cumbersome to operate and may fail to register 
an intended entry. Additionally, many of the mechanical counters do not 
provide means for deleting an erroneously entered count. Many counters 
have no means for preventing the simultaneous entry of two individual 
counts leading to another source of inaccurate entries. 
By necessity, the prior art counters employ intricate mechanical components 
and are therefore costly to manufacture and require a certain amount of 
maintenance to enable them to operate smoothly and accurately. Mechanical 
components also impose certain size and weight contraints on the apparatus 
as well as power requirements where the mechanical registers are actuated 
by electromechanical devices. 
It is therefore, an object of the present invention to provide an 
electronic calculator-register which is capable of providing running 
totals of individual cell counts as well as a total cell count and means 
for calculating the percentage of the individual counts to the whole at 
any time during the count. 
It is also an object of the present invention to provide a 
calculator-register for cell differentials wherein the running totals and 
the individual cell percentages are conveniently displayed. 
It is a further object of the present invention to provide a 
calculator-register for cell differentials which is of solid state 
construction employing a minimum of mechanical elements thereby resulting 
in a unit which is small in size and highly responsive and reliable in its 
operation. 
A further object of the present invention is to provide an electronic 
calculator-register capable of rapidly and accurately providing individual 
cell percentages by means of simple keyboard entries regardless of the 
total cell count. 
Another object of the present invention is to provide an electronic 
calculator-register for cell differentials wherein double count entries 
are prevented. 
Yet another object of the present invention is to provide an electronic 
calculator-register for cell differentials which permits easy deletion of 
incorrectly entered counts. 
A still further object of the present invention is to provide an electronic 
caculator-register for cell differentials including audible means for 
signaling the technician when a single cell count has been entered and for 
providing a different audible signal when 100 counts have been entered. 
Yet another object of the present invention is to provide an electronic 
calculator-register for cell differentials which can be economically mass 
manufactured at a low unit cost. 
These and other object of the present invention will be apparent from the 
detailed description together with the appropriate drawings. 
SUMMARY OF THE INVENTION 
An electronic calculator-register for hematology differentials comprising 
manually operable data entry means having a first plurality of manually 
actuated input elements, each input element having means for entering data 
signifying a single event when actuated; the data entry means having a 
second plurality of manually actuated input elements for entering 
numerical data and instructional commands; computation means having a 
plurality of channels operatively connected to the data entry means for 
storing the data entered therein and performing mathematical computations 
on the entered data in response to instructional commands; the computation 
means including channel register means associated with each of the 
channels and operatively connected to the first plurality of input 
elements for computing and storing individual running totals of the number 
of events entered by each of the input elements and a total register means 
for computing and storing a collective running total of the number of 
events entered by the first input elements collectively; the computation 
further including means for storing numerical representing the collective 
running total entered therein by the second plurality of input elements 
and performing a mathematical operation involving the entered numerical 
data and the individual running totals to convert each individual total to 
a number equal to the decimal fraction of the particular individual total 
to the collective total; and display means for concurrently displaying the 
individual and collective totals before the mathematical operation and for 
concurrently displaying the decimal fractions after the mathematical 
operation.

DETAILED DESCRIPTION 
In basic terms, the calculator-register of the present invention comprises 
a single keyboard which has a plurality of outputs to seven separate 
channels through a switching and pulse generating network which permits 
separate running totals to be stored and displayed by six of the channels 
and a running total of the combined count stored in the seventh channel. 
In the calculate mode, each of the totals stored in the individual 
channels are divided by the combined total count to display the individual 
count as a percentage of the total. 
With reference to FIG. 1, the calculator-register is illustrated and 
comprises a case 110 having a face plate 112 on which are mounted a 
plurality of manually operable keys comprising keyboard 114 for the entry 
of data, and mode switches 116 and 118, the latter serving to switch the 
device between the Count and Calculate modes and Delete and Add modes, 
respectively. Also present on the face plate 112 are six windows 120 which 
permit viewing of LED readouts which display the data presently stored in 
each of the channels. Another window 122 permits viewing of the LED 
readouts associated with the total cell count channel. 
The case 110 and face plate 112 may be made of plastic or various metals or 
other forms of structural materials. Switches 116 and 118 are preferably 
slide switches and the keys of keyboard 114 are of the standard spring 
loaded single pole type employed in hand-held calculators which close 
switches when depressed. Keys 124, 126, 128, 132 and 134 carry the decimal 
numbers 1 through 6 and are also provided with indicia representing the 
particular type of cell being entered. For example, key 124 is depressed 
to enter a single count for monocytes, key 126 for lymphocytes, key 128 
for neutrophils, key 130 for eosinophils, key 132 for basophils and key 
134 for stabs. Windows 120 have appropriate indicia associated with them 
corresponding to the indicia keys 124-134. If desired the indicia on keys 
124-134 could be varied depending on the particular count being performed. 
Key 136 is a clear function and key 138 the division function entry 
switch. Due to the fact that solid state circuitry is employed, the 
tabulator may be relatively small in size so that it is highly portable 
and capable of hand-held operation. 
In FIG. 2, the relationship between the keyboard entries and the individual 
counter/calculators is illustrated. This is a greatly simplified diagram 
and merely represents the various flow paths of data entered by the keys. 
Corresponding to FIG. 1, keys 124-134 carry indicia identifying the 
particular cells being counted as well as decimal intergers 1 through 6. 
Keys 140, 142, 144 and 146 are identified with the decimal intergers 7, 8, 
9 and 0, respectively and keys 136 and 138 the clear function and division 
function, respectively. Associated with keys 124-138 are a plurality of 
counter/calculators 148, 150, 152, 154, 156, 158 and 160 wherein 
counter/calculators 148-158 comprise channels 1 through 6 and 
counter/calculator 160 constitutes channel 7, which is the total cell 
count channel. An oscillator 162 is associated with the total 
counter/calculator 160 to provide an audible signal whenever an entry is 
made therein. 
Keys 124-134 are dual function in nature and activate different circuits 
depending on whether the device in the Count or Calculate mode as 
controlled by the position of slide switch 116. In the count mode, the 
depression of keys 124 enters an integer 1 in counter 148 through path 164 
and in counter 160 through path 166. Subsequent depression of keys 124 
will enter a second integer 1 in counters 148 and 160 and add this integer 
to the sum previously stored therein. In a similar fashion, depression of 
keys 128 will enter an integer 1 in counter 152 through path 170 and will 
enter an integer 1 in counter 160 through path 172 and 166. The remainder 
of keys 124-134 are associated with counter/calculators 148-160 in the 
same manner and cause an integer 1 to be added to the sum presently stored 
in its respective counter as well as adding an integer 1 to the collective 
sum stored in counter 160. Each time that an integer 1 is entered into 
counter 160, oscillator 162 will emit an audible signal to notify the 
technician that the entry has been made. In the Count mode, keys 140, 142, 
144, 146 and 138 are not operable. Depression of key 136 when the device 
is in the Count mode causes the totals stored in each of the 
counter/calculators 148-160 to be cleared. 
When switch 116 is moved to the Calculate position, all the switches 
124-146 are rendered operable to enter numerical data into all of the 
counter/calculators 148-160 simultaneously. In the Calculate mode, 
depression of switch 124 will enter an integer 1 in all of the 
counter/calculators; actuation of key 128 will enter an integer 3 in all 
of the counter/calculators; actuation of key 142 will enter an integer 8 
in all of the counter/calculators. If keys 126, 132 and 134, for example, 
are actuated in sequence, the number 256 will be entered in all of the 
counter/calculators 148-160. Following the entry of any numerical data, 
the actuation of divide-by key 138 followed by the entry of another number 
and then the reactuation of key 138 will cause the first entered number to 
be divided by the second number. In the Calculate mode, the actuation of 
key 136 at any time will cause the divisor to be cleared. 
Briefly, the apparatus operates as follows. Switch 116 is moved to the 
Count position and switch 118 to the Add position. As the technician 
observes the blood sample under the microscope, he depresses one of 
switches 124-134 each time that particular cell is observed thereby 
entering an integer 1 into the counter/calculator 148-158 associated with 
the particular cell and an integer 1 into counter/calculator 160 which 
stores a count of the total number of cells observed. Should an incorrect 
entry be made, switch 118 may be moved to the Delete position and the 
particular key 124-134 with which the incorrect entry was made is actuated 
so that an integer 1 is deleted from its respective counter/calculator as 
well as from the total counter/calculator 160. When a total of 300 cells, 
for example, have been observed, switch 116 is moved to the Calculate 
position and the total number (in this case 300) observed through display 
window 122 is intered into all of the channels by depressing key 138 once, 
key 128 once and key 146 twice. At this point, the number 300 will appear 
in windows 120 and 122. Key 138 is then depressed a second time causing 
the individual and the total counts to be divided by the number 300 and 
the quotient to appear in windows 120 and 122. The numbers so appearing 
represent the percentage of each of the individual cells in relation to 
the total number of cells counted. FIGS. 3A, 3B and 3C constitute a 
detailed composite circuit diagram of the present invention of which FIG. 
2 is a general representation. The right portion of FIG. 3A joins with the 
left portion of FIG. 3B at points 0-20 and the right portion of FIG. 3B 
joins with FIG. 3C at points 0 through 13 and 21 through 41. 
Switch S.sub.13 corresponds to slide switch 116 and is operative to switch 
the device between the Count and Calculate mode by placing a 9 volt 
inhibit voltage on monostable multivibrators IC.sub.1 -IC.sub.12 through 
diodes D.sub.1 -D.sub.12 in the Count mode. Multivibrators IC.sub.1 
-IC.sub.12, which are SN 74121 multivibrators, receive this 9 volt inhibit 
voltage at pins 3. In the Calculate mode, switch S.sub.13 is moved to the 
"b" position thereby placing a 9 volt inhibit on multivibrators IC.sub.13, 
IC.sub.15 -IC.sub.20 and IC.sub.42 through diodes D.sub.15, D.sub.21 
-D.sub.26 and D.sub.14. 
Switches S.sub.1 -S.sub.10 correspond to keys 124-146, switch S.sub.11 
corresponds to divide-by key 138 and switch S.sub.12 to key 136 so that 
when the respective key is depressed by the technician, its corresponding 
switch S.sub.1 -S.sub.12 is closed. In the Calculate mode, the closing of 
any of switches S.sub.1 -S.sub.12 causes a negative impulse to trigger its 
respective monostable multivibrator IC.sub.1 -IC.sub.12 through 
resistor-capacitor circuits R.sub.1 C.sub.1 -R.sub.12 -C.sub.12. When 
these monostable multivibrators are triggered, a 20 millisecond negative 
impulse is generated and fed into counter/calculators 148-160 through the 
appropriate line 1 through 12. The 20 millisecond impulse is taken from 
multivibrators IC.sub.1 -IC.sub.12 off pin 1 and passes through blocking 
circuit R.sub.33 C.sub.33 --R.sub.41 C.sub.41 for multivibrators IC.sub.1 
-IC.sub.9, respectively, through R.sub.45 C.sub.44 for IC.sub.10, through 
R.sub.42 C.sub.42 for IC.sub.11 and through R.sub.43 C.sub.43 for 
IC.sub.12. By adjusting the value of the resistor-capacitor circuit for 
multivibrators IC.sub.1 -IC.sub.12, such as R.sub.15 and C.sub.15 for 
IC.sub.1 and R.sub.18 C.sub.18 for IC.sub.4A, the duration of the output 
pulse can be adjusted. By virtue of the connection scheme illustrated in 
FIG. 3C, the output pulse from any one of multivibrators IC.sub.1 
-IC.sub.12 will be entered in each of counter/calculators 148-160. As 
mentioned previously, in the Calculate mode each of the switches S.sub.1 
-S.sub.10 causes the entry of integers 1 through 0, respectively. 
Similarly, the closing of switch S.sub.11 enters an instructional command 
for the division function and the closing of switch S.sub.12 causes the 
divisor to be cleared. The details of this will be described at a later 
point. 
In the Count mode, switch S.sub.13 is in position a thereby placing a 9 
volt inhibit voltage on monostable multivibrators IC.sub.1 -IC.sub.12 and 
multivibrators IC.sub.13 -IC.sub.20 and IC.sub.42 are released. Upon the 
closing of one of switches S.sub.1 through S.sub.6 and switch S.sub.12, a 
negative going impulse travels through line 176-188, respectively, to pin 
3 of the respective multivibrators IC.sub.13, IC.sub.15 -IC.sub.20 and 
IC.sub.42. For example, the closing of switch S.sub.2 causes the negative 
going impulse to trigger IC.sub.16 through line 176, closing of switch 
S.sub.5 triggers IC.sub.19 through line 184 ad the closing of switch 
S.sub.12 triggers IC.sub.13 through line 188. 
When multivibrators IC.sub.15, IC.sub.16, IC.sub.17, IC.sub.18, IC.sub.19, 
IC.sub.20 or IC.sub.42 are triggered, they produce a negative going pulse 
of 25 milliseconds duration at pin 1 which triggers its adjacent 
multivibrator IC.sub.21, IC.sub.22, IC.sub.23, IC.sub.24, IC.sub.25, 
IC.sub.26, IC.sub.27, respectively, through the intermediate 
resistor-capacitor circuit R.sub.55 C.sub.55 -R.sub.61 C.sub.61, 
respectively, which in turn produces a negative going impulse of 20 
milliseconds duration at output pin 1 which in turn is entered in its 
respective counter/calculator 148-160 through line 21, 24, 27, 30, 33, 36 
or 39, respectively. The input lead for the entry of an interger 1 in this 
fashion is designated as terminal 14 on counter/calculators 148-160. 
In the Add mode, switch S.sub.14 is in the b position which inhibits 
multivibrators IC.sub.35 -IC.sub.41 by placing a 9 volt bias on pins 3 
thereof. In the Delete mode S.sub.14 is in the a position which places the 
9 volt inhibit voltage on pins 3 of multivibrators IC.sub.28 -IC.sub.34. 
In the Add mode and after the 20 millisecond negative going pulse is 
entered on lead 14 of counter/calculator 148-160, multivibrators IC.sub.15 
-IC.sub.20 and IC.sub.42 produce a second 20 millisecond negative going 
pulse which activates multivibrators IC.sub.28 -IC.sub.34, respectively, 
through the appropriate connection 190-198. The triggered multivibrator 
IC.sub.28 -IC.sub.34 produces a 20 millisecond negative going impuse which 
is entered into its respective counter/calculator 148-160 through lines 
22, 25, 28, 31, 34, 37, and 40. This causes the counter/calculator to 
perform an addition operation on the previously entered integer so that 
the integer 1 is added to the total presently stored therein. 
In the Delete mode, switch S.sub.14 is in the a position thereby placing a 
9 volt inhibit bias on multivibrators IC.sub.28 -IC.sub.34 and removing 
the bias from multivibrators IC.sub.35 -IC.sub.41. When one of the 
multivibrators IC.sub.15 -IC.sub.41, rather than the adjacent 
multivibrator IC.sub.28 -IC.sub.34, will be triggered and will generate an 
impulse on pin 1 and connecting line 23, 26, 29, 32, 35, 38 and 41, 
respectively, to enter an instructional command to its respective 
counter/calculator 148-160 causing an integer 1 to be subtracted from the 
number previously stored therein. In the Delete mode, the functioning of 
switches S.sub.1 -S.sub.6 and multivibrators IC.sub.15 -27 and IC.sub.42 
is the same as the Add mode. 
As indicated earlier, the timing and spacing of the pulses generated by the 
various multivibrators is controlled by the resistive-capacitive circuit 
connected thereto in a manner well known in the art. 
Channel 7 counter/calculator 160 is the counter which tabulates the total 
number of countes entered in individual channels 1-6. When one of switches 
S.sub.1 -S.sub.6 are closed, the negative impulse on lines 176-178 are 
also fed into multivibrator IC.sub.14 by means of lines 200 and 202. The 
output from multivibrator IC.sub.14 triggers multivibrator IC.sub.42 which 
in turn triggers IC.sub.27 to place a negative going pulse to line 39 
which enters an integer 1 into total counter/calculator 60 by way of 
terminal 14. The functioning of multivibrators IC.sub.34 and IC.sub.41 for 
the Add and Delete modes is identical to the general operation of the 
circuitry in FIG. 3B described above. 
To prevent a simultaneous entry in two or more of the channels with only a 
single entry into the channel 7 counter/calculator 160 thereby rendering 
an inaccuract divisor, means are provided for inhibiting entry into more 
than one of channels 1-6 when one of the switches S.sub.1 -S.sub.6 is 
closed. This is accomplished by means of multivibrator IC.sub.14 which 
produces a 50 millisecond positive going pulse on pin 6, lines 204, 
through diodes D.sub.21 -D.sub.26 and lines 14-19 to multivibrators 
IC.sub.15 -IC.sub.20. The presence of this 50 millisecond positive pulse 
on the input pin to the last mentioned multivibrators has the effect of 
balancing a negative going pulse from any of switches S.sub.1 S.sub.6 if 
same should be actuated during the 50 millisecond folloiwng the triggering 
of multivibrator IC.sub.14. After the 50 millisecond inhibit, however, 
counter/calculator 160 has completed entry of the previous integer and is 
receptive the entry of another integer. By this time, multivibrators 
IC.sub.15 -IC.sub.20 will again be rendered operable by the removal of the 
positive inhibiting voltage and are capable of being triggered. 
As evidenced in the field of hand-held portable calculators, complex 
counting and operational functions can be achieved by TTL semiconductor 
chips. These normally employ a multi-digit LED readout which is 
multiplexed and scanned many times per second to reduce the amount of 
wiring and to minimize current consumption. Due to the versitility and 
ease of connection with such calculator chips, it is possible to tailor 
their operation according to the requirements of the specific application. 
Referring to FIGS. 4 and 5, the counter/calculator chips shown generally in 
FIG. 3C are illustrated in somewhat greater detail especially with regard 
to the transistor triggering circuit and its input leads which correspond 
to the terminals shown on counter/calculator chips 148-160. At the heart 
of the counter/calculator, is a Texas Instruments calculator chip CP 7541 
identified as IC.sub.100, having terminals numbered consecutively 1 
through 28. Due to the complexity of such a calculator chip and the fact 
that it is commerically available, no details of its construction are 
included herein. The chip is capable, however, of entering numbers, 
storing the numbers, performing the mathematical operations of addition, 
subtraction and division and providing output signals to DED display LED 1 
in a manner well known in the art. LED 1 is a universal 9 digit LED 
display having input pins numbered sequentially from 1 to 17 as 
illustrated. 
In FIG. 4 is illustrated the transistor switching network interface between 
the pulse generating circuit of FIGS. 3A, 3B and 3C and IC.sub.100 shown 
in FIG. 5. The 11 input lines to the calculator chip-LED circuit of FIG. 5 
and numbered 0 through 10 correspond to the outputs of the transistor 
triggered circuit of FIG. 4. Since negative going pulses are utilized to 
enter data and instructional commands in the counter/calculator, diodes 
D.sub.100 through D.sub.1700 are employed to provide isolation from 
positive pulses and voltages. Transistors T.sub.1 -T.sub.15 are 
commercially available 2N4917 transistors and connected in such a manner 
that negative going pulses on individual ones of input terminals 1 through 
16 cause triggering of different combinations of output terminals 1 
through 9. 
The interface circuit, calculator chip and LED display shown in FIGS. 4 and 
5 operates generally in the following manner. When a negative going pulse 
is placed on input terminal 1 in FIG. 4, transistor T.sub.1 turns on 
causing calculator chip IC.sub.100 to enter the integer 1 therein. If a 
negative going pulse is then placed on lead 15, the previously entered 
integer 1 is added to the number previously stored therein and the 
resultant sum is retained in the memory. A negative pulse on terminal 2 in 
FIG. 4 turns on transistor T.sub.4 Causing the entry an integer 2 in 
calculator chip IC.sub.100. A negative pulse on terminal 15 causes the 
entered integer to be added whereas a negative pulse on terminal 16 
following the entry of integer 2 will cause it to be subtracted from the 
sum previously stored therein and the resultant difference retained in the 
memory. In like fashion, negative pulses on terminals 3, 4, 5, 6, 7, 8, 9 
and 10 causes transistors T.sub.5 -T.sub.12, respectively, to be turned on 
thereby entering the integers 3, 4, 5, 6, 7, 8, 9 and 0, respectively, in 
calculator chip IC.sub.100. If negative pulses are sequentially placed on 
a number of terminals 1 through 10, a multiple digit number will be 
entered. For example, negative pulses on terminals 3, 8 and 1 in 
succession will cause the number 381 to be entered. Subsequent negative 
pulsing of terminal 15 or 16 will cause the entered number to be added or 
subtracted from the number previously stored therein. 
As to the other operational terminals, a negative pulse on terminal 11 sets 
chip IC.sub.100 in a state whereby it is receptive for the entry of a 
divisor. By entering a number and then again pulsing terminal 11, this 
causes the first number stored in the chip IC.sub.100 to be divided by the 
number entered after the first pulsing of terminal 11 to produce a 
quotient which is the first number divided by the second. A negative pulse 
on terminal 12 causes the count total to be cleared and pulsing terminal 
13 causes the divisor to be cleared. A negative pulse on terminal 14, 
which comes into play during the Count mode, agan turns on transistor key 
1 thereby causing the entry of an integer 1. 
Each time terminal 15 is pulsed, thereby signifying the addition of an 
integer, monostable multivibrator 206 in FIG. 6 is triggered which in turn 
provides an output pulse to transistor T.sub.101 thereby causing the 
osciallator circuit to produce a short duration tone burst of audio 
frequency which is emitted by speaker 208. This audio signal indicates to 
the technician, who is normally observing this sample under the microscope 
without looking at the tabulator display, that the entry has been 
registered by the counter/calculator. 
It should be noted that the interface circuit illustrated in FIG. 4 and the 
calculating chip-LED display of FIG. 5 are associated with only a single 
channel, for example channel 7, which is the total cell count channel. 
Identical circuits are provided for each of counter/calculators 148-158 
and have input terminals 1 through 16 which correspond to those shown in 
FIG. 3C. With reference to FIG. 3C, all entries into the 
counter/calculators 148-160 on terminals 1 through 13 inclusive are common 
to each of them. The lines connecting to terminals 14, 15, and 16, 
however, which serve to enter individual counts of one in addition to the 
add or subtract operational commands, are unique to each of the 
counter/calculator channels. By virtue of monostable multivibrator 
IC.sub.14 having an input which is common to switches S.sub.1 through 
S.sub.6, however, the entry of an integer 1 into any of 
counter/calculators 148-158 results in the entry of an integer 1 into the 
total channel counter/calculator 160 so that a total cell count may be 
provided. 
OPERATION 
With the counter/calculators cleared, the technician moves switch 116 to 
the Count position and switch 118 to the Add position which places switch 
S.sub.13 in the a position and switch S.sub.14 in the b position. This 
results in a 9 volt inhibit voltage being placed on Calculate mode 
multivibrators IC.sub.1 -IC.sub.12 and delete function multivibrators 
IC.sub.35 -IC.sub.41. 
While observing the blood sample under the microscope, the technician 
depresses one of switches 124, 126, 128, 130, 132 and 134 each time a 
particular cell corresponding to that channel is observed. For example, 
assume that a lymphocyte is observed. The technician depresses key 126 
which causes switch S.sub.2 to be closed thereby placing a negative 
impulse on line 178 which triggers multivibrator IC.sub.16. The negative 
impulse on line 178 is fed to the input of multivibrator IC.sub.42 through 
line 200 and connection 20. Multivibrator IC.sub.2 will not be triggered 
due to the positive 9 volt vias on its input through diode D.sub.2. 
When multivibrator IC.sub.16 is triggered, it produces a negative going 
impulse of 25 milliseconds duration which is fed to the input of IC.sub.22 
through RC circuit R.sub.56 C.sub.56. Multivibrator IC.sub.22 in turn 
produces a negative going impulse of 20 milliseconds duration which is fed 
to terminal 14 of channel 2 counter/calculator 150 along line 24. Assuming 
for the moment that the interface circuit and calculating chip illustrated 
in FIGS. 4 and 5 corresponds to channel 2 counter/calculator 150, the 
negative going 20 millisecond pulse on terminal 14 will turn on transistor 
T.sub.1 through diode D.sub.200 thereby triggering the appropriate inputs 
of calculator chip IC.sub.100 to enter an integer 1. LED 1 will display 
this entry. Multivibrator IC.sub.16 then produces a second negative going 
pulse from pin 6 which triggers multivibrator IC.sub.29 at pin 3 through 
line 192. Although multivibrator IC.sub.36 is also connected to the output 
of IC.sub.16 along line 192, it will not be triggered due to the positive 
9 volt inhibit voltage at its input. Multivibrator IC.sub.29 produces a 20 
millisecond negative going pulse which is fed to terminal 15 of 
counter/calculator 50 along line 25. This causes transistor T.sub.2 to 
turn on which causes chip IC.sub.100 to perform an addition operation on 
the previously one thereby yielding a resultant sum of 1 and providing for 
this display on LED 1. 
Since a negative impulse is also present on line 20 of FIGS. 3A and 3B due 
to the closure of switch S.sub.2, multivibrator IC.sub.42 will be 
triggered to produce a 25 millisecond negative pulse which triggers 
multivibrator IC.sub.21 to produce a 20 millisecond negative going impulse 
on line 39 and terminal 14 of the Total counter/calculator 60. Assuming 
for the moment that the interface circuit and calculating chip shown in 
FIGS. 4 and 5 corresponds to channel 7 counter/calculator 60 rather than 
counter/calculator 50, the negative impulse on terminal 14 causes 
transistor T.sub.1 to turn on thereby entering an integer 1 in chip 
IC.sub.100 which causes display of this number on LED 1. 
Multivibrator IC.sub.42 will then produce a second negative going pulse 
which triggers multivibrator IC.sub.34 to produce a 20 millisecond 
negative going pulse on line 40 and lead 15 of counter/calculator 160. The 
pulse on terminal 15 turns on transistor T.sub.2 thereby causing chip 
IC.sub.100 to perform an addition function on the previously entered 
integer 1. As will be recalled, IC.sub.41, although connected to 
multivibrator IC.sub.42 by line 198, will not be activated due to the 9 
volt inhibit voltage present at its input to diode D.sub.27. When the 
addition function pulse is fed to terminal 15 of the interface circuit in 
FIG. 4, line 150 will feed a negative pulse to multivibrator 206 in FIG. 6 
thereby causing the oscillator to generate a short duration tone which is 
acoustically reproduced by speaker 208. The technician will therefore be 
aware that the entry has been made without the necessity for looking up 
from the slide which he is observing in the microscope. At this point in 
time, an integer 1 is stored in counter/calculator 150 and 
counter/calculator 160 and is displayed on their corresponding LED 1 
displays. 
Assume now that the technician observes a basophil. He will depress key 132 
thereby closing switch S.sub.5 and placing a negative impulse on line 184 
which in turn triggers multivibrator IC.sub.19 through line 18. A negative 
going pulse will also be transmitted to multivibrator IC.sub.42 through 
lines 220. Multivibrator IC.sub.19 will produce a 25 millisecond negative 
going impulse which triggers adjacent multivibrator IC.sub.25 thereby 
placing a 20 millisecond negative going impulse on line 33 and terminal 14 
of counter/calculator 156. Again assuming for the moment that the 
circuitry in FIGS. 4 and 5 represents counter/calculator 156, the negative 
impulse on terminal 14 turns on transistor T.sub.1 and enters an integer 1 
into chip IC.sub.100. Multivibrator IC.sub.19 will then produce a second 
negative going impulse of 20 milliseconds duration which triggers 
multivibrator IC.sub.32 through line 195. Multivibrator IC.sub.32 produces 
a 20 millisecond negative going impulse and feeds this to terminal 15 of 
counter/calculator 156 along line 34. This turns on transistor T.sub.2 and 
causes chip IC.sub.100 to perform an addition operation on the previously 
entered integer 1 thereby producing a resultant sum of 1 in the memory and 
displaying this on LED 1. 
Since IC.sub.42 has also been triggered simultaneously with IC.sub.19, it 
will emit a negative going pulse to trigger multivibrator IC.sub.27 which 
feeds a negative pulse to terminal 14 and counter/calculator 160 along 
line 39. Assuming for the moment that the circuitry of FIGS. 4 and 5 
represents counter/calculator 160, this will turn on transistor T.sub.1 
and enter an integer 1 in chip IC.sub.100 which in turn displays this 
integer 1 on LED 1. Multivibrator IC.sub.42 then produces a second 
negative going pulse on line 198 which triggers multivibrator IC.sub.34 to 
produce a 20 millisecond negative going impulse on line 40 and terminal 15 
of counter/calculator 160. This turns on transistor T.sub.2 to add the 
previously entered integer 1 to the integer 1 which is already stored 
therein by virtue of the entry of the lymphocyte observation to produce a 
resultant sum of 2 which is then displayed on LED 1. The negative pulse on 
line 150 causes the oscillator of FIG. 6 to emit a short tone through 
speaker 208. At this point in time, counter/calculator 150 is storing and 
displaying an integer 1, counter/calculator 156 an integer 1 and 
counter/calculator 160 is storing an integer 2. 
In the two operations described above, multivibrator IC.sub.14 is triggered 
by virtue of the negative pulse on lines 200 and 202 and produces a 50 
millisecond positive going impulse on pin 6 which is transmitted to the 
inputs of multivibrators IC.sub.15 -IC.sub.20 and IC.sub.42 through diodes 
D.sub.21 -D.sub.26 and D.sub.14, and lines 14-20, respectively. This 
inhibits the triggering of multivibrators IC.sub.15 -IC.sub.20 and 
IC.sub.42 for a period of approximately 50 milliseconds. Although the 
multivibrator IC.sub.15 -IC.sub.20 and IC.sub.42 which is connected 
directly to switches S.sub.1 -S.sub.6 has already been triggered by the 
time the 50 millisecond pulse reaches its input, rapid closure of another 
switches S.sub.1 -S.sub.6 will be unable to cause a subsequent triggering 
until the positive voltage is removed after the inhibit period. This is 
necessary to prevent entry into two or more of channels 1 through 6 in 
rapid succession before channel 7 is able to respond to the second entry. 
If this were to occur, the count stored in the channel 7 
counter/calculator 160 would be lower than the total of all counts stored 
in channels 1 through 6. Since the 50 millisecond time period is very 
short in relation to the ability of the technician to rapidly depress two 
switches in succession under normal counting conditions, it has no 
appreciable affect on the effeciency of the device. 
If the technician observes another lymphocyte, he will depress key 126 
thereby triggering multivibrators IC.sub.16 and IC.sub.22 to enter an 
integer 1 in counter/calculator 150, with the second negative pulse from 
multivibrator IC.sub.16 triggering multivibrator IC.sub.29 to add this 
second entered integer 1 to the integer 1 previously stored therein and 
causing its associated LED 1 to display an integer 2. Simultaneously, 
multivibrator IC.sub.42 will be triggered which in turn triggers 
multivibrators IC.sub.27 and IC.sub.34 to enter an integer 1 into 
counter/calculator 160 which is added to the integer to previously stored 
therein thereby displaying an integer 3 as the resultant sum. Since 
multivibrator IC.sub.14 will also be triggered, a 50 millisecond positive 
going inhibit pulse will be placed on the inputs to multivibrators 
IC.sub.15 -IC.sub.20 and IC.sub.42 shortly after multivibrators IC.sub.16 
and IC.sub.42 are triggered. 
Should the technician make a mistake and press key 130 when he intended to 
depress key 128, multivibrator IC.sub.18 will be triggered causing 
multivibrators IC.sub.24 to pulse terminal 14 of counter/calculator 154 
thereby entering an integer 1 into its calculating chip IC.sub.100. The 
second negative pulse from multivibrator IC.sub.18 will trigger IC.sub.31 
to enter an Add pulse on terminal 15 of counter/calculator 154. 
Simultaneously, multivibrator IC.sub.42 will be triggered to enter and add 
an integer 1 to counter/calculator 160. At this point, counter/calculator 
150 will display a 2, counter/calculator 156 a 1, counter/calculator 154 a 
1 and counter/calculator 160 a 4. To correct the improper entry, the 
technician moves switch 118 to the Delete position which places a 9 volt 
inhibit voltage on terminal a of switch 14 thereby inhibiting 
multivibrators IC.sub.28 -IC.sub.34 and removing the inhibit voltage from 
multivibrators IC.sub.35 -IC.sub.41. The technician will then again 
depress key 130 which closes switch S.sub.4 and triggers multivibrator 
IC.sub.18. IC.sub.18 produces a first negative going pulse of 25 
millisecond duration which triggers adjacent multivibrator IC.sub.24 to 
enter an integer 1 into counter/calculator 154. The second negative pulse 
from multivibrator IC.sub.18 will be fed to the input of multivibrator 
IC.sub.38 along line 194 which in turn produces a negative pulse at 
terminal 16 of counter/calculator 154 along lines 32. Again assuming the 
circuitry in FIGS. 4 and 5 represents counter/calculator 154, the negative 
pulse on terminal 16 will cause transistor T.sub.3 to turn on thereby 
entering a delete function pulse to chip IC.sub.100 which has the effect 
of subtracting an integer 1 to the integer 1 previously stored therein. 
When this is done, LED 1 will display a zero. 
Simultaneously, multivibrator IC.sub.42 will initiate a sequence of events 
to enter an integer 1 into counter/calculator 160 and the second pulse 
along line 198 will not activate multivibrator IC.sub.34 due to the 9 volt 
inhibit voltage and will trigger multivibrator IC.sub.41 to produce a 
negative going pulse on line 41 and a terminal 16 of counter/calculator 
160. In a similar fashion to counter/calculator 154, this will cause the 
previously entered integer 1 to be subtracted from the number 4 previously 
stored and the resulting integer 3 which is from that point on displayed 
on LED 1. 
To make the correct entry, switch 118 is again moved to the Add position 
and the correct key depressed. 
Should it be desired to clear all of channels 1-7, switch 116 is moved to 
the Count position and key 138 depressed. This closes switch S.sub.12 
which triggers multivibrator IC.sub.13 to produce a negative going pulse 
on line 13 thereby turning on transistor T.sub.15 in all of 
counter/calculators 148-160. This causes the totals stored therein to be 
cleared and a zero to be displayed by their respective displays LED 1. 
Assuming the technician has counted and entered 140 cells and that the 
stored and displayed numbers for each of the channels is as follows: 
Counter/Calculator 49 (monocytes): 3 
Counter/Calculator 50 (lymphocytes): 67 
Counter/Calculator 52 (neutrophils): 60 
Counter/Calculator 54 (eosenophils): 4 
Counter/Calculator 56 (basophils): 1 
Counter/Calculator 58 (stabs): 5 
Counter/Calculator 60 (total): 140 
The technician then moves switch 116 to the Calculate position which causes 
switch S.sub.13 to place a 9 volt inhibit voltage on terminal b and at the 
inputs to multivibrators IC.sub.15 -IC.sub.20 and IC.sub.42 through lines 
14-20, respectively. At the same time, the inhibit voltage is removed from 
the inputs to multivibrators IC.sub.1 -IC.sub.12. Since the total number 
of cells counted is 140, the technician enters this number into each of 
the counter/calculators 148-160. This is done by first depressing key 138 
which closes switch S.sub.11 thereby triggering multivibrator IC.sub.11 to 
transmit a negative pulse over line 11 to input terminal 11 of each 
counter-calculator 148-150. In each channel, this turns on transistor 
T.sub.13 which sets the respective chips IC.sub.100 ready for the entry of 
a common divisor. The total number appearing in window 122, which in this 
case is 140 is then entered by sequentially depressing keys 124, 130 and 
210. This triggers multivibrators IC.sub.1, IC.sub.4, IC.sub.10 to 
transmit negative pulses to the input terminals 1, 4 and 10 of each of the 
counter/calculators 148-160 thereby turning on transistors T.sub.1, 
T.sub.6 and T.sub.12. This causes each IC.sub.100 to enter the number 140 
and this number will be displayed in each of the channel displays LED 1. 
After the numerical value has been entered, key 38 is again depressed 
which triggers IC.sub.11 to enter the divide-by function on terminal 11 
which in turn turns on transistor T.sub.13 to cause each calculating chip 
IC.sub.100 to divide the individual counts stored therein by the common 
division which has just been entered. 
The numbers then displayed by the appropriate channel LED's and visible 
through windows 20 and 22 are the following: 
Counter/Calculator 48 (monocytes): .02 
Counter/Calculator 50 (lymphocytes): .48 
Counter/Calculator 52 (neutorphils): .43 
Counter/Calculator 54 (eosenophils): .03 
Counter/Calculator 56 (basophils): .01 
Counter/Calculator 58 (stabs): .03 
Counter/Calculator 60 (total): 1.00 
Since the numbers which are then stored and displayed are equal to the 
individual counts divided by the total cell count, the represent the 
decimal fraction of each cell to the total cells. By disregarding the 
decimal point, the numbers so displayed are the percentages of each cell 
observed by the technician. Since the device includes means for dividng 
the individual cell counts by the total, it is not necessary for the 
technician to stop the count at 100 but can continue as long as he wishes 
without the need for performing manual computations. 
If a mistake is made in the entry of the divisor, depression of key 136 in 
the Calculate mode will close switch S.sub.12 thereby triggering 
multivibrator IC.sub.13 to enter a negative pulse on terminal 13 of each 
channel counter/calculator 148-160 which turns on the respective 
transistors T.sub.15 to clear the divisor therefrom. The total accumulated 
counts stored in each channel remain, however. 
If desired, a second oscillator 212 may be connected to terminals 14 and 16 
of counter/calculator 60 through an electronic counter 214. The purpose of 
this is to emit an audible signal whenever 100 counts are entered in 
counter/calculator 160. Each time a negative pulse is sensed on terminal 
15, the counter with the advanced by an increment of 1 and each time a 
pulse is present on terminal 16, which occurs when an interger 1 is being 
deleted from the counter/calculator 160, counter 214 would be backed up by 
one. Oscillator 212 will sound when a total count of 100 is registered by 
counter 214. 
The following components may be employed in construction of the tabulating 
device described herein: 
______________________________________ 
S.sub.1 -S.sub.12 Switching Panel 
R.sub.33 -R.sub.43 100k ohm 
S.sub.13 SPST R.sub.44 33ohm 
S.sub.14 SPST R.sub.45 100k ohm 
D.sub.1 -D.sub.40 1N914 
R.sub.46 100 k ohm 
Multivibrators IC.sub.1 -42 SN 74121 
R.sub.47 -54 2200ohm 
R.sub.1 -R.sub.14 100k ohms 
R.sub.55 -R.sub.61 100 k ohm 
R.sub.15 -R.sub.32 33 ohms 
R.sub.62 -75 33 ohm 
R.sub.76 -82 100 k ohm 
R.sub.300 100 k ohm 
R.sub.83 -89 33 ohm 
R.sub.500 -R.sub.800 330 ohm 
R.sub.90 -96 100 k ohm 
C.sub.100 25 pf 
C.sub.1 -14 .001 mf 
C.sub.101 20 mf 
C.sub.15 -32 20 mf 
C.sub.201 .1mf 
C.sub.33 -43 .001 mf 
C.sub.301 1 mf 
C.sub.44 20 mf C.sub.401 .001 mf 
C.sub.45, C.sub.46 1001 mf 
R.sub.101 4.4 k ohm 
C.sub.47 -54 20 mf 
R.sub.201 2.2 k ohm 
C.sub.55 -61 .001 mf 
R.sub.301 68 k ohm 
C.sub.62 -75 20 mf 
R.sub.401 1.5 kohm 
C.sub.76 -82 .001 mf 
R.sub.601 2.2 k ohm 
C.sub.83 -89 20 mf 
R.sub.701 2.2 k ohm 
C.sub.90 -96 .001 mf 
D.sub.101 1N914 
D.sub.100 -D.sub.1700 1N914 
T.sub.101 2N4917 
T.sub.1 -T.sub.15 2N917 
T.sub.201 2N414 
LED 1 Universal 9 Digit 
Multivibrator IC.sub.206 SN 74121N 
IC.sub.100 TMC 0952 N.sub.1 7528 
R.sub.801 1 k ohm 
R.sub.100 56 k ohm 
L.sub.101 4 Hy 
R.sub.200, R.sub.400 58 k ohm 
Spkr. 208 3.2 ohm speaker 
______________________________________ 
Although the preferred embodiment has been described as comprising a large 
number of independently wired electronic elements, it is possible to 
incorporate the entire circuit into a single chip using present 
technology. Alternate circuits using parallel counting and dividing 
register can also be complexed in a single chip. Displays such as liquid 
crystal displays, nixie tubes, etc. are also feasible in lieu of the LED 
displays. Furthermore, any number of Count channels could be provided and 
is not limited to six. 
While this invention has been described as having a preferred design, it 
will be understood that it is capable of further modification. This 
application is, therefore, intended to cover any variations, uses, or 
adaptations of the invention following the general principles thereof and 
including such departures from the present disclosure as come within known 
or customary practice in the art to which this invention pertains, and as 
may be applied to the essential features hereinfore set forth and fall 
within the scope of this invention or the limits of the appended claims.