CAPTUS 600 Manual

CAPINTEC, INC. CAPTUS® 600

INTERPRETING WIPE RESULTS

The data shown in Figure 13-9 and Figure 13-12 are the results of a measurement with only
Cs137.

W-01 HOT LAB SINK
Trig Level: 2000

A CF: 1600 87.75 +1.05 kdpm HIGH

B CS137 193.5 + 4.2 kdpm HIGH

200 keV 5086. + 179. cpm
C 326 keV 4257. + 164. cpm

376 keV 3953. + 158. cpm

COUNT GRAPH NEXT P

Figure 13-12

• Line A indicates that the Generic CF result has exceeded the Trigger Level set up in
the Wipe Setup/Trigger Levels. This is a good indication that either there was
contamination on the wipe, or that the background has changed. If you suspect a
background change, re-measure background and re-measure the wipe.

• Line B indicates that the CAPTUS® 600 has detected a peak within 5% of the energy
of the main peak of Cs137. Although there is a good chance that the CAPTUS® 600
has identified the presence of the nuclide on the wipe, it has only identified a peak at
a particular energy. The user must decide if the data is consistent with nuclides used
in the department.

• Line C indicates that peaks were found at the indicated energies; they are artifacts.

The peak search algorithm used in Wipe is very sensitive. It is not unusual to detect artifact
peaks. You should enter CFs for the nuclides that are used and therefore, may possibly find
on a wipe, but do not enter CFs for nuclides that you do not use.

Many nuclides have energies for more than 1 peak listed (refer to the Diagnostics printout). If
the nuclide has been found, the secondary and tertiary peaks will not be listed. For example,
Cs137's 33 keV peak was not listed.

If a nuclide’s main peak is within 5% of the peaks of a nuclide that is really in the Wipe, the
second nuclide may be listed even though it is not in the Wipe. Therefore, do not enter CF's
for nuclides that you do not use.

November 07 WIPE TEST 13-9



CAPINTEC, INC. CAPTUS® 600

CHAPTER 14

LAB TESTS SETUP

INTRODUCTION

The Lab Tests chapters describe protocols programmed into the CAPTUS® 600 for use with
certain lab tests based upon radiopharmaceuticals. These tests are:

CATEGORY TEST NAME PHARMACEUTICAL
URINE Schilling Test Cyanocobalamin Co57 Capsules
Blood Volume (Cr51) Sodium Chromate Cr51
BLOOD Blood Volume (I 125) Iodinated I 125 Albumin
Red Blood Cell Survival Sodium Chromate Cr51

The protocols for these tests are based upon data provided by manufacturers of the
radiopharmaceuticals in the package inserts. It is strongly recommended that before using
the CAPTUS® 600 to perform any of the above tests, the package inserts of the materials be
read carefully. Check to be sure the protocol in the CAPTUS® 600 is correct for the tests
performed at your site. In general, the procedures have been designed around the
instructions outlined in the Mallinckrodt package insert for the selected tests.

The CAPTUS® 600 expects that the samples for the Lab Tests will be counted in the Well. If
the system has only a Probe with a Drilled Crystal, then the samples must be placed in the
Drilled Crystal for counting.

This introductory chapter describes the parts of the Lab Tests that are the same (or very
similar) for all of the Lab Tests.

GENERAL PROCEDURE

The methods for using the Lab Test protocols in the CAPTUS® 600 for the various tests are
very similar. The basic steps are as follows:

1. Enter patient demographics
2. Count previously prepared samples
3. View and print report

The CAPTUS® 600 stores the patient demographics until the patient is deleted. The results
for the individual tests are not stored in memory. At the conclusion of the test, the system
reminds the user to print the report before exiting the program. Once the program has ended,
the data is lost.

November 07 LAB TESTS SETUP 14-1

CAPINTEC, INC. CAPTUS® 600

The CAPTUS® 600 has the ability to store demographics for 50 patients in memory. This is
the total number of patients and they can be distributed in any combination throughout the
tests, except in the RBC Survival where only two tests may be recorded simultaneously.
However, the patient demographic data is included in the total of 50. The RBC Survival tests
store the results during the period of the tests (up to 60 days). This is the only test that stores
the results.

STARTING LAB TESTS

Accessing the Lab Tests section of the CAPTUS® 600 program is the same for all the tests.
To access the Lab Tests section, press the WELL key. The Main Well Screen (Figure 14-1)
will appear.

WELL 14:32

W IPE LAB
Figure 14-1

Press the F2 [LAB] key. The Main Lab Tests Screen (Figure 14-2) will appear.

14-2 LAB TESTS SETUP November 07

CAPINTEC, INC. CAPTUS® 600

LAB TESTS 14:32

URINE BLOOD

Figure 14-2

Press the F1 [URINE] key to access the Urine Test: Schilling Test.
Press the F2 [BLOOD] key to access the three Blood Tests: Blood Volume (Cr51), Blood
Volume (I125), RBC Survival.
Press the BSP key or the HOME key to return to the Main Well Screen (Figure 14-1).
Details for each test will be given in the next two chapters.

ENTERING PATIENT DEMOGRAPHICS

Patient demographics are entered in the same manner for each Lab Test. The Schilling Test
screens are used in the examples. The only difference for the other tests is the test name
heading.

If there are no patients in memory for the chosen test, Figure 14-3 will appear. If patient(s)
already exist for the chosen test, Figure 14-4 will appear.

SCHILLING TEST 14:32 SCHILLING TEST 14:32

> PATIENT , ONE
P A T IE N T , TWO

P A T IE N T , THR

NEW NEW EDIT DEL MEAS
Figure 14-4
Figure 14-3

November 07 LAB TESTS SETUP 14-3

CAPINTEC, INC. CAPTUS® 600

To add a patient, press the F1 [NEW] key.

To edit patient demographics, move the cursor next to the patient name and press the F2
[EDIT] key. Figure 14-5 will appear with the current data filled in.

To delete a patient, move the cursor next to the patient name and press the F3 [DEL] key.

To perform the chosen test, move the cursor next to the patient name and press the F4
[MEAS] key. A measurement can only be made after the patient demographics have been
entered.

After pressing the F1 [NEW] key, the Patient Demographics Screen (Figure 14-5) will
appear.

SCHILLING TEST 14:32
P A T IE N T
LAST
FIRST
ID #
DOB
PHYS
SEX :

SEX OK
Figure 14-5

Enter data in all the fields. The Date of Birth (“DOB”) field is optional. The “SEX” field is
toggled between “M” and “F” by pressing the F1 [SEX] key. When the data is correct, press
the F4 [OK] key. The system will return to the Patient Selection Screen (Figure 14-4) with the
new patient entered into the list.

To exit from the Patient Selection Screen, press BSP to return to the Main Urine Screen or
Main Blood Screen, or press HOME to return to the Main Well Screen (Figure 14-1).

MEASUREMENT PROCEDURE

Each test will step you through the necessary measurements. The procedure for each
measurement is similar. The measurement of the Standard for the Schilling Test will be used
as an example.

The Prompt Screen (Figure 14-6) will appear.

14-4 LAB TESTS SETUP November 07

CAPINTEC, INC. CAPTUS® 600

SCHILLING TEST 14:32
PATIENT, ONE

MEASURE STANDARD

EXIT START
Figure 14-6

Place the requested Standard into the Well and press the F4 [START] key to begin counting.

If you wish to abort the test (e.g. wrong test or patient chosen) press the F1 [EXIT] key to
return to Figure 14-4.

After pressing the F4 [START] key, the system will begin counting and a live spectrum will
be displayed as is shown in Figure 14-7.

500 dt: 3%
3 sec

ABORT STANDARD 200 keV
Figure 14-7

If a mistake has been made (e.g. measuring wrong sample), press F2 [ABORT] key.
When the counting is complete Figure 14-8 will appear on the display.

November 07 LAB TESTS SETUP 14-5

CAPINTEC, INC. CAPTUS® 600

500

9108 cpm
OK?
(Yor N)

STANDARD 200 keV

Figure 14-8

If the counting rate is OK, press the Y key and then the ENTER key to continue the test.
If the counting rate does not seem OK (e.g. measuring Background and counting rate is too
high), press the N key and the ENTER key and you will be returned to the Prompt Screen
(Figure 14-6) for the current measurement.
If a Standard or a sample is being measured, the CAPTUS® 600 uses an automatic peak
finding algorithm to look for the expected peak. If it cannot detect a peak or detects a peak
that clearly isn't from the expected nuclide, the Measurement Error Screen (Figure 14-9) will
appear to alert the user to a measurement error. If the Measurement Error Screen appears,
press any key to continue, check that the correct source has been put in the Well and count
again. If you are certain the correct Standard or sample was in the Well and the CAPTUS®
600 cannot measure it, contact the Capintec’s Authorized Service Center for assistance.
When Background is being measured, no peak is expected.

500

CALCULATING

MEASUREMENT ERROR

PRESS ANY KEY TO CONTINUE

Figure 14-9

14-6 LAB TESTS SETUP November 07

CAPINTEC, INC. CAPTUS® 600

CHAPTER 15

LAB TESTS: URINE TEST

INTRODUCTION

This chapter describes the Schilling Test Urine Test.

In the Main Lab Tests Screen, press the F1 [URINE] key. The Schilling Test Screen (Figure
15-1) will appear.

SCHILLING TEST 14:32

Figure 15-1

If patient demographics have not yet been input, do so according to the instructions in
CHAPTER 14 – LAB TESTS SETUP.

PERFORMING SCHILLING TEST MEASUREMENTS

To perform the actual measurements with this protocol, the system assumes the following
samples have been prepared for counting.

1. Aliquot of urine sample collected over the test period.
2. Co57 Standard having the identical volume and geometry as the test urine sample

above.

To perform the measurement, move the cursor next to the patient name with the ARROW
keys and press the F4 [MEAS] key. Figure 15-2 will appear.

November 07 LAB TESTS: URINE TEST 15-1

CAPINTEC, INC. CAPTUS® 600

SCHILLING TEST 14:32

PATIENT, ONE

COUNTING PERIOD: 300 SEC

DILUTION FACTOR : 1000

ALIQUOT VOLUME : 4.0 ml
URINE VOLUME : 1000 ml

OK
Figure 15-2

Input the correct values. The fields are defined as follows:

• Counting Period This determines how long the urine sample, room background and
the Co57 Standard will be counted. The units are in seconds. Enter
the real time desired. The unit counts for real time and then
corrects for any dead time in the calculation.

• Dilution Factor The ratio of the activity of the Co57 capsule to the activity of the
Co57 Standard. When using a 1% standard, the Dilution Factor
equals 100.

• Aliquot Volume Volume of urine taken from the full urine volume collected.

• Urine Volume Volume of urine collected over the duration of the test period. If the
urine has been diluted to a convenient volume (such as 2000 ml),
use this value.

When the data are correct, press the F4 [OK] key. The Schilling Test Measure Standard
Screen (Figure 15-3) will appear.

SCHILLING TEST 14:32
PATIENT, ONE

MEASURE STANDARD

EXIT START
Figure 15-3

Place the Co57 Standard into the Well and press the F4 [START] key to begin counting.

15-2 LAB TESTS: URINE TEST November 07

CAPINTEC, INC. CAPTUS® 600

After accepting the Co57 Standard measurement, the system will then prompt the user to
measure the room background. Remove any samples from the Well and count room
background. Next, measure the urine aliquot sample.

After accepting the Urine Sample measurement, the Schilling Test Result Screen (Figure 15-
4) will appear.

SCHILLING TEST 14:32

PATIENT, ONE : 60.53 cpm
: 535.1 kcpm
BACKGROUND : 6299. cpm
STANDARD
URINE

EXCRETION : 14.0%

DONE P
Figure 15-4

The percent excretion is calculated as:

( )%
100 × (U − B)× V A
(S − B)× D
excretion =

where
U = Urine count rate
B = Room Background
V = Urine Volume
S = Standard count rate
D = Dilution factor
A = Aliquot Volume

To print the results, press the PRINT [P] key. To return to the Main Schilling Test Screen,
press the F4 [DONE] key. If you press the F4 [DONE] key before printing, you will be
reminded that the data will be deleted. The message “Data will be deleted. OK? Y or N” will
appear on the display. At this point you may answer “NO” and go back and print the results
before deleting the data. The results of the test are not saved. Patient demographics are
saved.

Figure 15-5 is a sample Schilling Test printout.

November 07 LAB TESTS: URINE TEST 15-3

CAPINTEC, INC. CAPTUS® 600

Figure 15-5

15-4 LAB TESTS: URINE TEST November 07

CAPINTEC, INC. CAPTUS® 600

CHAPTER 16

LAB TESTS: BLOOD TESTS

INTRODUCTION

This section describes the three blood tests:
1. Blood Volume (Cr51)
2. Blood Volume (I 125)
3. RBC Survival (Cr51)

To access the Blood Test section of the program, press the F2 [BLOOD] key in the Main Lab
Tests screen. Figure 16-1 will appear.

BLOOD TESTS 14:32

1. BLOOD VOLUME (Cr51)
2. BLOOD VOLUME (I 125)
3. RBC SURVIVAL (Cr51)

Figure 16-1

BLOOD VOLUME (Cr51)

This protocol may used in the determination of Red Blood Cell Volume.
From the Main Blood Tests Screen (Figure 16-1), press 1 to select BLOOD VOLUME (Cr51).
If patient demographics have not yet been input, do so according to the directions in
CHAPTER 14: LAB TESTS: SETUP.
Press the F4 [MEAS] key after the patient demographics are entered. The RBC Volume
Measurement Screen (Figure 16-2) will appear.

November 07 LAB TESTS: BLOOD TESTS 16-1

CAPINTEC, INC. CAPTUS® 600

RBC VOLUME 14:32

PATIENT, ONE

DOSE HEMATOCRIT: 50 %
PATIENT HEMATOCRIT: 51 %

WEIGHT : 100.0 kg

OK
Figure 16-2

Input the data in the fields and press ENTER after each entry. The fields are defined as
follows:

• Dose Hematocrit Hematocrit of the tagged RBC suspension determined from the
remainder of the suspension of the injection into the patient.

• Patient Hematocrit Hematocrit of a blood sample withdrawn from the patient ten to
twenty minutes post injection.

• Weight Weight of the patient in kilograms.

When the data in Figure 16-2 are correct, press the F4 [OK] key. Figure 16-3 will appear.

RBC VOLUME 14:32

PATIENT, ONE

INJECTION TIME:
COUNTING PERIOD: 300 sec

OK

Figure 16-3

Input the Injection Time in 24 hour format (example 1:00 PM as 1300) and press ENTER.
Input the Counting Period, in seconds, for measurements. Press the F4 [OK] key. You will be
prompted to count the following samples in the Well.

• Whole Blood Standard 4 ml solution made from 1 ml of the tagged RBC
suspension diluted with water to 100 ml

16-2 LAB TESTS: BLOOD TESTS November 07

CAPINTEC, INC. CAPTUS® 600

• Plasma Standard 4 ml solution made from 1 ml of the plasma from the
centrifuged tagged RBC suspension diluted with water to
• Room Background 100 ml
• Whole Blood Sample
• Plasma Sample No samples in the Well

4 ml of blood withdrawn from the patient ten to twenty
minutes post injection.

4 ml of plasma from the blood withdrawn ten to twenty
minutes post injection.

Perform each measurement according to the instructions in CHAPTER 14: LAB TESTS:
SETUP.

After the plasma sample counts have been accepted, the RBC Volume (Cr51) Results
Screen (Figure 16-4) will appear.

RBC VOLUME 14:32

PATIENT, 18. ml/kg
37. ml/kg
RBC : 1290. ml 18. ml/kg
BLOOD: 2581. ml
PLASMA: 1290. ml

DONE P
Figure 16-4

RBC Volume is calculated as follows:

Red Cell Volume (ml) = [B − C(1 − A)]E ×1000
D − F(1 − E)

Where

A = Hematocrit of Tagged RBC Suspension
B = Net Whole Blood Standard Count
C = Net Plasma Standard Count
D = Net Patient Whole Blood Sample Count
E = Patient Hematocrit
F = Net Patient Plasma Sample Count

Whole Blood Volume (ml) = Red Cell Volume (ml)
Patient Hematocrit

November 07 LAB TESTS: BLOOD TESTS 16-3

CAPINTEC, INC. CAPTUS® 600

Plasma Volume (ml) = Whole Blood Volume (ml) - Red Cell Volume (ml)

To print the results press the PRINT [P] key. To return to the Main RBC Volume (Cr51) Test
Screen, press the F4 [DONE] key. If you press the F4 [DONE] key before printing, you will
be reminded that the data will be deleted. The message “Data will be deleted. OK? Y or N”
will appear on the display. At this point you may answer “NO” and go back and print the
results before deleting the data. The results of the test are not saved. Patient demographics
are saved.

Figure 16-5 is a sample RBC Volume (Cr51) Test printout.

16-4 LAB TESTS: BLOOD TESTS November 07

CAPINTEC, INC. CAPTUS® 600

Figure 16-5

November 07 LAB TESTS: BLOOD TESTS 16-5

CAPINTEC, INC. CAPTUS® 600

BLOOD VOLUME (I125)

The Blood Volume (I125) protocol is designed to be used in determining plasma volume.

From the Main Blood Tests Screen (Figure 16-1), press 2 to select BLOOD VOLUME (I125).

If patient demographics have not yet been input, do so according to the directions in
CHAPTER 14: LAB TESTS: SETUP.

Press the F4 [MEAS] key after the patient demographics are entered. The first Plasma
Volume Data Screen (Figure 16-6) will appear.

PLASMA VOLUME 14:32

PATIENT, ONE %
kg
HEMATOCRIT :

W E IG H T :

OK
Figure 16-6

Input the hematocrit determined from a whole blood sample drawn from the patient five to ten
minutes post injection and enter the patient weight. When data on the screen are correct,
press the F4 [OK] key.

After pressing the F4 [OK] key, the second Plasma Volume Data Screen (Figure 16-7) will
appear.

PLASMA VOLUME 14:32

PATIENT, ONE

INJECTION TIME:
COUNTING PERIOD: 300 sec

OK
Figure 16-7

16-6 LAB TESTS: BLOOD TESTS November 07

CAPINTEC, INC. CAPTUS® 600

Input the Injection Time in 24 hour format (example 1:00 PM as 1300) and press ENTER.

Input the Counting Period, in seconds, for measurements. Press the F4 [OK] key. You will be
prompted to count the following samples in the Well.

• Reference Standard Standard supplied with the kit.
• Room Background
• Whole Blood Sample Remove all samples and sources from the Well.

• Plasma Sample 4 ml of whole blood withdrawn from the patient five to ten
minutes post injection.

4 ml of plasma from the whole blood withdrawn from the
patient five to ten minutes post injection.

Perform each measurement according to the instructions in CHAPTER 14: LAB TESTS:
SETUP.

After the plasma sample counts have been accepted the RBC Volume (I125) Results Screen
(Figure 16-8) will appear.

PLASMA VOLUME 14:32

PATIENT, ONE

PLASMA: 5237. ml 75. ml/kg

BLOOD: 9879. ml 141. ml/kg
RBC: 4642. ml 66. ml/kg

CALCULATED HEMATOCRIT: 47.0 %

DONE P

Figure 16-8

Results are calculated as follows:
Plasma Volume (ml) = Net Reference Standard Counts × 4000
Net Plasma Counts

Whole Blood Volume (ml) = Net Reference Standard Counts × 4000
Net Whole Blood Counts

RBC Volume (ml) = Blood Volume - Plasma Volume

November 07 LAB TESTS: BLOOD TESTS 16-7

CAPINTEC, INC. CAPTUS® 600

Calculated Hematocrit = Red Cell Volume
Whole Blood Volume

To print the results press the PRINT [P] key. To return to the Main Plasma Volume (I125)
Test Screen press the F4 [DONE] key. If you press the F4 [DONE] key before printing, you
will be reminded that the data will be deleted. The message “Data will be deleted. OK? Y or
N” will appear on the display. At this point you may answer “N” and go back and print the
results before deleting the data. The results of the test are not saved. Patient demographics
are saved.

Note: A comparison of the radioactive hematocrit with the microhematocrit will give an
indication of the accuracy of the procedure and calculations.

The standard, blood, and plasma counts must be taken under identical sample volume and
geometric conditions relative to the detector crystal or else the difference accounted for in the
computations by an appropriate correction factor.

Figure 16-9 is a sample Blood Volume (I125 Albumin) Test printout.

16-8 LAB TESTS: BLOOD TESTS November 07

CAPINTEC, INC. CAPTUS® 600

November 07 Figure 16-9 16-9

LAB TESTS: BLOOD TESTS

CAPINTEC, INC. CAPTUS® 600

RED BLOOD CELL SURVIVAL

This protocol is used to count samples taken as part of a procedure to measure Red Cell
Survival time. The protocol is set up so that samples are counted as they are withdrawn. The
CAPTUS® 600 decay corrects the counts to the date and time the measurements are made.
The steps in using the RBC Survival protocol can be summarized as follows:

1. Inject patient with tagged RBC suspension.
2. At approximately 24 hours post injection, withdraw a blood sample, determine the

hematocrit, and count the sample in the Well. Save the results in the CAPTUS® 600.
This value will be used as 100%.
3. Every two or three days repeat step 2. Do this for a minimum of 30 days or until the
50% remaining level is reached.
4. Print results.

From the Main Blood Tests Screen (Figure 16-1), press 3 to select RBC SURVIVAL (Cr51).

Note: There is a limit of two patients in the RBC Survival directory.

If patient demographics have not yet been input, do so according to the directions in
CHAPTER 14: LAB TESTS: SETUP.

After the patient demographics are entered, Figure 16-10 will appear.

RBC SURVIVAL 14:32

PATIENT, ONE

INJECTION DATE:
INJECTION TIME :

OK

Figure 16-10

Input the date and time the tagged RBC suspension was injected into the patient. The date is
entered in the format chosen in Utilities, Date Format (default is MMDDYY) and the time is
entered in 24 hour format (HHmm).

When the date and time of the injection are correct, press the F4 [OK] key. You will be
returned to the RBC Survival Patient Selection Screen.

16-10 LAB TESTS: BLOOD TESTS November 07

CAPINTEC, INC. CAPTUS® 600

To make a measurement from the RBC Survival Patient Selection Screen, move the cursor
to the desired patient and press the F4 [MEAS] key. Figure 16-11 will appear.

RBC SURVIVAL 14:32

PATIENT, ONE

HEMATOCRIT :> %

COUNTING TIME : 300 SEC

OK
Figure 16-11

Input the Hematocrit determined from the sample to be counted and the Counting Period in
seconds. When the entered data is correct, press the F4 [OK] key.

You will be prompted to measure the Sample and then Room Background. Perform the
measurements according to the directions in CHAPTER 14: LAB TESTS: SETUP.

After the room background measurement is accepted, Figure 16-12 will appear if this is the
first measurement.

RBC SURVIVAL 14:32
PATIENT , ONE

EXIT SAVE P

Figure 16-12

Save this measurement by pressing the F4 [SAVE] key. This first measurement is used as
the 100% remaining measurement. All future measurements will be compared to this data
point.

To print the data, press the PRINT [P] key.

To exit the program at this point and return to the Main RBC Survival Screen, press the F1
[EXIT] key. If you try to exit without saving the data the system will confirm the choice by

November 07 LAB TESTS: BLOOD TESTS 16-11

CAPINTEC, INC. CAPTUS® 600

displaying a message that reads “Data not Saved OK? (Y or N)”. If you escape by pressing
the HOME key, the data is also lost.

For measurements after the first one, Figure 16-13 will appear after room background is
accepted:

RBC SURVIVAL 14:32
PATIENT , ONE

100
xx x x

50

Days 10 20 30 40 50

EXIT SAVE P

Figure 16-13

This shows a graph of the data with percent remaining on the Y-axis and days since injection
on the X-axis. The axis scales are fixed and data values outside the range of the graph will
not be plotted but will appear on the print out.

When 4 or more measurements have been made, the best-fit straight line through the data
points will be calculated and displayed on the graph. In addition, the 50% survival rate will be
calculated from the best fit.

At this point the data for each measurement must be saved in order to be included in the
report otherwise it will be lost.

For a report of detailed data press the PRINT [P] key. A sample printout is shown in Figure
16-14.

Percent Remaining (% LEFT on the print out) is calculated as follows:

% LEFT = NET CPM (sample) × Hematocrit (at 100%) ×100
NET CPM (at 100%) Hematocrit (sample)

16-12 LAB TESTS: BLOOD TESTS November 07

CAPINTEC, INC. CAPTUS® 600

Figure 16-14

November 07 LAB TESTS: BLOOD TESTS 16-13



CAPINTEC, INC. CAPTUS® 600

CHAPTER 17

STAFF BIOASSAY

STAFF BIOASSAY DATA

All staff members who work with Iodine-131, Iodine-125, or Iodine-123 need to have regular
Bioassay measurements taken to monitor exposure levels. Most state and federal radiation
safety regulations mandate that these thyroid measurements be taken periodically.

The CAPTUS® 600 can store data for up to 20 staff members for Bioassay measurements.
The CAPTUS® 600 uses one bioassay protocol, which is user-defined.

Before using the Capintec CAPTUS® 600 system to perform Bioassay measurements on the
staff, the staff member names, ID numbers and initials should be stored in the CAPTUS® 600
memory (if not, the results can't be saved), as well as the parameters for the Bioassay
protocol.

Press the HOME key then the UTIL key. The main Utilities menu (Figure 17-1) will appear.

UTILITIES 14:32

1. MULTICHANNEL ANALYZER
2. STAFF BIO ASSAY RESULTS
3. SETUP
4. DIAGNOSTICS

0. RETURN TO PROBE SCREEN

Figure 17-1

Note: Selection 0 will display “RETURN TO WELL SCREEN” if the Utilities menu is
accessed from the Well main screen.

Press 3 to select SETUP. The message “PASSWORD:” will appear. Type the last three digits
of your CAPTUS® 600 serial number, and press the ENTER key. The Setup menu (Figure
17-2) will appear.

November 07 STAFF BIOASSAY 17-1

CAPINTEC, INC. CAPTUS® 600

SETUP 14:32

1. Ci/Bq
2. TEST DATA
3. THYROID UPTAKE
4. BIO ASSAY
5. AUTO CALIBRATION
6. ACTIVITY CONVERSION FACTORS
7. WIPE AND MCA SETUP
8. OTHER

0. RETURN TO UTILITIES MENU

Figure 17-2

Press 4 to select BIOASSAY. The Bioassay Setup menu (Figure 17-3) will appear.

BIO ASSAY SETUP 14:32

1. STAFF DATA
2. BIO ASSAY PROTOCOL

0. RETURN TO SETUP MENU

Figure 17-3

Adding Staff Member
From the Bioassay Setup menu (Figure 17-3), press 1 to select STAFF DATA. The Staff
Name List Screen (Figure 17-4) will appear.
If there are no staff names stored in the CAPTUS® 600 memory, the list part of the screen is
blank (Figure 17-5). All function keys except for F1 [ADD] and F4 [DONE] are also blank.

17-2 STAFF BIOASSAY November 07

CAPINTEC, INC. CAPTUS® 600

BIOASSAY STAFF DATA 14:32 BIOASSAY STAFF DATA 14:32

> SEELEY ,D
SOPCHACK ,S
NAIM ,V

LEMISZKO ,J

ADD EDIT DEL DONE P ADD DONE
Figure 17-4 Figure 17-5

Press the F1 [ADD] key. The Staff Data Screen (Figure 17-6) then appears.

BIOASSAY STAFF DATA 14:32

STAFF MEMBER
LAST :>
FIRST :
MID :
ID# :

INIT :

OK

Figure 17-6

The LAST and FIRST name can include up to 20 letters.

MID is the middle initial and is only 1 letter.

ID# can include up to 20 numbers.

When all information has been entered, press the F4 [OK] key. The screen returns to the
Staff Name List Screen (Figure 17-4) with the new name added.

Editing Staff Member Data
To edit staff data in the CAPTUS® 600 memory, follow the instructions at the beginning of
this chapter until you reach the Staff Name List Screen (Figure 17-4 and Figure 17-5).

Use the ARROW keys to position the cursor next to the name you want to revise, and press
the F2 [EDIT] key.

November 07 STAFF BIOASSAY 17-3

CAPINTEC, INC. CAPTUS® 600

Use the ARROW keys to position the cursor at the line you need to change, input the revised
data, and then press the ENTER key. When the information on the screen is correct, press
the F4 [OK] key.

The Staff Name List Screen (Figure 17-4) will re-appear.

Deleting a Staff Member
To delete a staff member's name from the CAPTUS® 600 memory, follow the instructions at
the beginning of this chapter until you reach the Staff Name List Screen (Figure 17-4 and
Figure 17-5).

Use the ARROW keys to position the cursor next to the name you want to delete, and press
the F3 [DEL] key. The following message, with the appropriate last name and first three
letters of the first name in the second line, will appear on the screen:

DO YOU WANT TO DELETE
Y OR N

To answer “YES”, press the Y key, then press the ENTER key. The screen returns to the
Staff Name List Screen (Figure 17-4 and Figure 17-5) with that name deleted from the list.

To answer “NO”, press the N key, then press the ENTER key. The screen returns to the Staff
Name List Screen (Figure 17-4 and Figure 17-5) unchanged.

ENTERING THE BIOASSAY PROTOCOL

To define your CAPTUS® 600 Bioassay protocol, follow the instructions at the beginning of
this chapter until you reach the Bioassay Setup menu (Figure 17-3).

Press 2 to select BIOASSAY PROTOCOL. The Bioassay Protocol Screen (Figure 17-7) will
appear.

BIO ASSAY PROTOCOL 14:32

COUNTING PERIOD :> 60 SEC
X-RAY / GAMMA (I131) : 8.5%

X-RAY / GAMMA(I123) : 92%

DISTANCE : 25.0 CM

OK

Figure 17-7

17-4 STAFF BIOASSAY November 07

CAPINTEC, INC. CAPTUS® 600

Input the desired Counting Period; the maximum accepted value is 999 seconds, and the
minimum accepted value is 1 second.

X-RAY/GAMMA RATIO

These factors are necessary because the I125 X-Ray peak overlaps with the I131 X-Ray
peak and the I123 X-Ray peak. The CAPTUS® 600 calculates I125 activity in Bioassay by
first searching for the I131 peak at 364 keV. If the I131 peak is detected, the contribution
from the I131 X-ray (counts in the I131 gamma peak times the I131 X-Ray gamma ratio) is
subtracted from the I125 X-Ray region of interest. It then searches for the I123 peak at
159keV. If the I123 peak is detected, the contribution from the I123 X-Ray (counts in the I123
gamma peak times the I123 X-Ray gamma ratio) is subtracted from the I125 X-Ray region of
interest. The default values are 8.5% for I131 and 92% for I123 and have been derived from
actual test data.

The last field is the DISTANCE, in centimeters, between the Probe and the neck. This must
be set to the same distance used in calculating Conversion Factors for the Probe for I125,
I123 and I131.

When all information is correct, press the F4 [OK] key.

Note: In order to report the Bioassay in units of activity rather than in counts, the CAPTUS®
600 must have Conversion Factors for I125, I123 and I131 in the Probe in memory.
Reference CHAPTER5: SYSTEM INITIALIZATION, SECTION CONVERSION
FACTORS.

The Bioassay Setup menu (Figure 17-3) will re-appear.

Note: It is possible to perform a Bioassay without associated staff data. The results of such
a test will not be stored.

MAKING BIOASSAY MEASUREMENTS

In the Main Probe Screen, press the F4 [BIO] key. The Bioassay Initials Screen (Figure 17-
8) will appear:

November 07 STAFF BIOASSAY 17-5

CAPINTEC, INC. CAPTUS® 600

BIO ASSAY 14:32
INPUT INITIALS:

BKG MEAS
Figure 17-8

At this point, you may enter the initials for the staff member to be measured. You may then
measure room background before measuring the staff member's neck.

Input the initials and press ENTER. (This is optional but must be done to save and print the
results.)

To measure background first, press the F1 [BKG] key.

To skip measuring the background, press the F4 [MEAS] key.

Room background must be measured in the Probe on the 400 keV scale at least once on the
current day before a Bioassay can be performed. If room background has not yet been
measured today or you have chosen to measure background, you will be prompted to
measure room background by pressing the F4 [START] key. While counting, the live
spectrum will be displayed. When the counting is complete, accept the measurement by
pressing the F4 [DONE] key.

The Bioassay Staff Measurement Screen (Figure 17-9) will appear.

14:32

MEASURE NECK
AT: 20.0 CM

EXIT START
Figure 17-9

17-6 STAFF BIOASSAY November 07

CAPINTEC, INC. CAPTUS® 600

At this point, you may abort the measurement by pressing the F1 [EXIT] key.

If you are to continue with the measurement, first position the staff member in front of the
Probe at the distance prescribed in Bioassay protocol. Press the F4 [START] key.

Note: In order for the Bioassay measurements to give accurate results, the distance used
for measuring the CF for I123, I125 and I131 must be the same as the one used in
the actual Bioassay protocol.

While the measurement is being taken, the live spectrum will be displayed. The system will
count for the time specified in the Bioassay protocol.

When the acquisition is complete, press the F4 [DONE] key. The Bioassay Report Screen
(Figure 17-10) will appear.

BIO ASSAY
I 131: 51.29 + .69 cpm

.023 + .003 μ Ci

I 123: -22.41 + 60.88 cpm
I 125: -10.41 + 50.75 cpm

Press any key to

Figure 17-10

If a Conversion Factor has been measured for I131, I125 or I123 the results will be displayed
in cpm and µCi (or cps and kBq for Bq). If the Conversion Factor has not been entered or
measured for these nuclides, the results will be displayed in cpm only.

Note: The Conversion Factor is only valid for the same distance at which the reference
source was measured.

PRINTING STAFF BIOASSAY RESULTS

To print all stored Bioassay results, press the HOME key and then the UTIL key to access
the main Utilities menu. Press the 2 key to select STAFF BIOASSAY RESULTS.

If data has been entered for more than one staff member, you will have the choice of printing
measurement results for one staff member or all staff members.

Figure 17-11 will appear with the default of all staff members:

November 07 STAFF BIOASSAY 17-7

CAPINTEC, INC. CAPTUS® 600

STAFF BIOASSAY 14:32

REPORT FOR ALL STAFF MEMBERS

ONE OK
Figure 17-11

If you want a report for only one staff member, press F1 [ONE]. Figure 17-12 will appear.

STAFF BIOASSAY 14:32

REPORT FOR ONE STAFF MEMBER

ALL OK
Figure 17-12

To return to the option of printing a report for all staff members, press F1 [ALL].

When the desired option is displayed, press F4 [OK].

If the option of All Staff Members has been chosen, a report of the data for all the Staff
Members will be printed.

If the option of One Staff Member has been chosen, the list of staff members will be
displayed as shown in Figure 17-13.

17-8 STAFF BIOASSAY November 07

CAPINTEC, INC. CAPTUS® 600

STAFF BIOASSAY 14:32
SELECT

> DOE ,J
SMITH ,A

Figure 17-13

Use the ARROW keys to move the prompt to the desired Staff Member and press ENTER.
A report of the data for the chosen Staff Member will be printed.
If data has been entered for only one Staff Member, the report will be printed as soon as
Staff Bioassay Results is chosen.
After the report is printed, the following message will appear:

DELETE EXPOSURE DATA?
Y OR N

If you answer “YES”, all the data will be deleted even if data has been printed for only one
staff member.

November 07 STAFF BIOASSAY 17-9



CAPINTEC, INC. CAPTUS® 600

CHAPTER 18

MULTICHANNEL ANALYZER SETUP

INTRODUCTION

The CAPTUS® 600 is equipped with a general-purpose Multichannel Analyzer (MCA). The
features of the MCA include:

• Optional Automatic Background Subtract
• Total/Net Reporting
• Automatic Peak Search
• Pre-Set Regions of Interest and Regions of Interest selected from Spectrum
• Selectable Vertical Scale
• Four Gain Ranges
• Selectable Low Level Cutoff Channel
• Selectable Count Times
• Storage of Frequently Used Setups for MCA Measurements

MCA SETUPS

Four MCA Setups can be stored in the CAPTUS® 600.

To add, edit, or delete a MCA Setup, press the HOME key and then the UTIL key. The main
Utilities menu (Figure 18-1) will appear.

UTILITIES 14:32

1. MULTICHANNEL ANALYZER
2. STAFF BIO ASSAY RESULTS
3. SETUP
4. DIAGNOSTICS

0. RETURN TO PROBE SCREEN

Figure 18-1

Note: Selection 0 will display “RETURN TO WELL SCREEN” if the Utilities menu is
accessed from the Well main screen.

November 07 MULTICHANNEL ANALYZER SETUP 18-1

CAPINTEC, INC. CAPTUS® 600

Press 3 to select SETUP. The message “PASSWORD:” will appear. Type the last three digits
of your CAPTUS® 600 serial number, and press the ENTER key. The Setup menu (Figure

18-2) will appear.

SETUP 14:32

1. Ci/Bq
2. TEST DATA
3. THYROID UPTAKE
4. BIO ASSAY
5. AUTO CALIBRATION
6. ACTIVITY CONVERSION FACTORS
7. WIPE AND MCA SETUP
8. OTHER

0. RETURN TO UTILITIES MENU

Figure 18-2

Press 7 to select WIPE AND MCA SETUP. The Wipe and MCA Setup menu (Figure 18-3)
will appear.

WIPE AND MCA SETUP 14:32

1. WIPE DESCRIPTIONS
2. USER KEY ASSIGNMENTS
3. ADDITIONAL NUCLIDES
4. GENERIC CONVERSION FACTORS
5. TRIGGER LEVEL/COUNT TIME
6. MCA SETUP

Figure 18-3
Press 6 to select MCA SETUP. Figure 18-4 will appear.

18-2 MULTICHANNEL ANALYZER SETUP November 07

CAPINTEC, INC. CAPTUS® 600

MULTICHANNEL ANALYZER 14:32
SETUP

> SETUP 200

ADD EDIT DEL DONE P

Figure 18-4

Setups that have been entered will be listed. If no setups have been entered, only the F1
[ADD} and F4 [DONE] keys will be displayed.

Adding a Setup
Press F1 [ADD] to add a setup. Figure 18-5 will appear.

MULTICHANNEL ANALYZER 14:32
SETUP

NAME: >

NUM OK
Figure 18-5

Input the name of the setup (up to 20 characters).
Press F1 [NUM] to switch to numeric input and display “LET” for F1.
Press F1 [LET] to switch back to letter input and display “NUM” for F1.
Press F4 [OK] when the correct name has been entered.
The Parameter Entry Screen (Figure 18-6) will appear with the default values displayed.

November 07 MULTICHANNEL ANALYZER SETUP 18-3

CAPINTEC, INC. CAPTUS® 600

MULTICHANNEL ANALYZER 13:06
SETUP

ENERGY SCALE : 200 keV
PEAK COUNTS : 100

COUNTING TIME :> 60 SEC X

CUT OFF CHANNEL : 5

COUNTING TIME BASE: REAL

ENRGY BASE P/T OK

Figure 18-6

The MCA counting can stop when the counting time is reached or when the Peak Counts
(i.e. Full Scale Counts) reach a given value. Only one of these options is active. The “X”
indicates that Counting Time is active.

Input the Counting Time in seconds and Low-level Cutoff Channel. Any input pulses that are
measured below this cutoff channel will be ignored by the MCA. To calculate the cutoff in
keV, divide the desired cutoff in keV by the gain of the energy range selected. The gains for
the energy ranges are as follows:

200 keV scale .......... 1 keV/Channel
400 keV scale .......... 2 keV/Channel
800 keV scale .......... 4 keV/Channel
1600 keV scale .......... 8 keV/Channel

EXAMPLE: For a 40 keV cutoff on the 400 keV full scale range, the desired cutoff channel
is calculated as:

cutoff channel = 40 keV = 20
2 keV / Channel

Press F1 [ENRGY] to change the Energy Scale from 200 keV to 400 keV to 800 keV to 1600
keV.

Press F2 [BASE] to switch the Counting Time Base between REAL and LIVE (Reference
CHAPTER 3: GENERAL OPERATING OVERVIEW for an explanation of Real and Live
Time).

Press F3 [P/T] to switch between Peak Counts and Counting Time.

When Peak Counts is selected, the “X” will move from the Counting Time to the Peak Counts
as shown in Figure 18-7.

18-4 MULTICHANNEL ANALYZER SETUP November 07

CAPINTEC, INC. CAPTUS® 600

MULTICHANNEL ANALYZER 13:06
SETUP

ENERGY SCALE : 200 keV
PEAK COUNTS : 100 X

COUNTING TIME :> 60 SEC

CUT OFF CHANNEL : 5

COUNTING TIME BASE: REAL

ENRGY PEAK P/T OK

Figure 18-7

Press F2 [PEAK] to scroll Peak Counts through the possible values (from 100 to 1024k)

When all entries are correct, press F4 [OK].

Up to 4 Regions of Interest may be entered. The Region of Interest number will be displayed
as shown in Figure 18-8.

MULTICHANNEL ANALYZER 13:06
SETUP

ROI NUMBER: 1

FROM CHANNEL: >
TO CHANNEL:

DEL OK

Figure 18-8
Entering Regions of Interest is optional.
If a pre-set Region of Interest is desired, input the “FROM” and “TO” channels (both must be
entered). The values range from 0 to 254.
Press F1 [DEL] to delete an ROI that has been entered.
Press F3 [OK] when the entries are correct.
If no ROI has been entered, or there was a ROI # 4, the last entry screen will be displayed:

November 07 MULTICHANNEL ANALYZER SETUP 18-5

CAPINTEC, INC. CAPTUS® 600

MULTICHANNEL ANALYZER 13:06
SETUP

DONE P
Figure 18-9
Press PRINT [P] to print a summary of the Setup.
Press F4 [DONE] when entering the setup is finished.
You will be returned to the list of existing setups.

Editing a Setup
To edit an existing setup, move the cursor to the desired setup and press F2 [EDIT].

The screens are the same as in adding a setup, except that the current values are displayed.

Deleting a Setup
To delete an existing setup, move the cursor to the desired setup and press F3 [DEL].

You will be asked if you want to delete that setup. Answer Y to delete it. Answer N if it was
chosen by mistake.

Printing All the Setups
To print all the setups, press PRINT [P] when the setups are listed.

18-6 MULTICHANNEL ANALYZER SETUP November 07

CAPINTEC, INC. CAPTUS® 600

CHAPTER 19

MULTICHANNEL ANALYZER
OPERATION

MCA MEASUREMENTS

The Multichannel Analyzer can be used for measurements in the Well or Probe.

Press the HOME key and then the UTIL key. The main Utilities menu (Figure 19-1) will
appear.

UTILITIES 14:32

1. MULTICHANNEL ANALYZER
2. STAFF BIO ASSAY RESULTS
3. SETUP
4. DIAGNOSTICS

0. RETURN TO PROBE SCREEN

Figure 19-1

Press 1 to select MULTICHANNEL ANALYZER. The Multichannel Analyzer Select Input
Screen (Figure 19-2) will appear.

MULTICHANNEL ANALYZER
SELECT INPUT

1. WELL
2. PROBE

0. RETURN TO UTILITIES MENU

Figure 19-2

November 07 MULTICHANNEL ANALYZER OPERATION 19-1

CAPINTEC, INC. CAPTUS® 600

Press the key corresponding to the desired input. Figure 19-3 will appear.
MULTICHANNEL ANALYZER 14:32

1. MEASURE SOURCE
2. MEASURE BACKGROUND
3. CHOOSE SETUP

Figure 19-3

If it is desired to use a setup that has been entered through Utilities, press 3 to select
CHOOSE SETUP. A list of the setups will be displayed. Use the ARROW keys to move the
prompt to the desired setup and press ENTER.

Calibration
It is not necessary to perform the Calibration Test every day in order to use the MCA.
If calibration has not been performed, Gain will be displayed instead of keV for the spectra.
The relationship between Gain and keV scales is:

200 keV .......... Gain 8
400 keV .......... Gain 4
800 keV .......... Gain 2
1600 keV .......... Gain 1
In addition, not all of the features will be active.

MEASURING BACKGROUND

Measuring background is optional.
Background for one or all of the energy ranges can be measured at once.
When MEASURE BACKGROUND is chosen, a background instruction message appears.
When any key is pressed, the Background Range Selection Screen (Figure 19-4) will appear.

19-2 MULTICHANNEL ANALYZER OPERATION November 07

CAPINTEC, INC. CAPTUS® 600

MULTICHANNEL ANALYZER 13:06
BACKGROUND SETUP

> 200 KEV 400 KEV
800 KEV 1600 KEV

SEL OK
Figure 19-4

Use the ARROW keys to move the prompt to the desired range. Press F1 [SEL] to select a
range. The range will be highlighted and the prompt will move to the next range. If the prompt
points to an already selected range, F1 will change to [DESEL] and pressing it will de-select
the range.

When all desired energy ranges have been selected, press F4 [OK]. Figure 19-5 will appear.

MULTICHANNEL ANALYZER 13:06
BACKGROUND SETUP

COUNTING TIME :> 60 SEC

OK

Figure 19-5

Input the desired Counting Time and press F4 [OK] to begin the background measurement.
When the counting is complete, the MCA Background Results Screen (Figure 19-6) will
appear. (The features of this screen are explained in Figure 19-8)

November 07 MULTICHANNEL ANALYZER OPERATION 19-3

CAPINTEC, INC. CAPTUS® 600

100 Cts FS 256 keV cc: 3 TOTAL
lt: 10.0 sec

COUNT RANGE SAVE SC/CR 5 400 keV P

Figure 19-6

The function keys on this screen operate as follows:

• F1 [COUNT] Re-counts the background without saving the current
measurement.

• F2 [RANGE] Switches between the selected ranges. This key will be blank and
inactive if only one energy range was chosen.

• F3 [SAVE] Saves the displayed spectrum to memory. The word “SAVED” is
displayed.

• F4 [SC/CR] Used to either change the vertical scale of the display or the
number of channels the cursor will move for each press of an
ARROW key. (Reference the F4 [SC/CR] section on page 19-7 for
usage instructions.)

• PRINT [P] Prints the Background Measurement.

To exit Background and measure Sources, press the BSP key. The Measurement Selection
Screen (Figure 19-3) will re-appear.

MEASURING A SOURCE

When MEASURE SOURCE is chosen, screens similar to MCA Setup will appear (except for
the name screen). If a Setup has been chosen, the values stored in the Setup will be
displayed. If no Setup has been chosen, the default values will be displayed. Even if a Setup
has been chosen, the values can be changed at this point, but they will only be valid for this
measurement and will not be stored.

The ROI Entry Screens will appear.

19-4 MULTICHANNEL ANALYZER OPERATION November 07

CAPINTEC, INC. CAPTUS® 600

MULTICHANNEL ANALYZER 13:06
SETUP

ROI NUMBER: 1

FROM CHANNEL: >
TO CHANNEL:

DEL OK START

Figure 19-7

Press F4 [START] to begin the measurement.

If the background has not been measured for the chosen energy scale during the current
calendar day, the following message will appear:

BACKGROUND NOT YET MEASURED
WITH THIS ENERGY SCALE

MEASURE BACKGROUND NOW?

If you answer “YES”, the Background Range Selection Screen will appear with the chosen
range highlighted. Proceed as if Background had been selected.

During the measurement of the source, the F2 [STOP] key can be pressed whenever it
appears that enough counts have been accumulated.

Note: During counting, the percent dead time will be displayed in the upper right hand
corner.

When the measurement is completed, the Results Screen (Figure 19-8) will appear.

November 07 MULTICHANNEL ANALYZER OPERATION 19-5

CAPINTEC, INC. CAPTUS® 600

CD E
F
500 Cts FS 250 keV CC:21 TOTAL

B

lt: 9.9sec

A

COUNT T/N ROI SC/CR 5 400 keV P

G

Figure 19-8

A: Cursor
B: Vertical Full Scale (Counts)
C: Cursor Position
D: Counts at Cursor
E: Indicates whether Total or Net Counts are being displayed.
F: Indicates the Live Time of the measurement.
G: Indicates the number of channels the cursor will move each time an ARROW

key is pressed. This can be changed by pressing the 1, 2, or 5 keys. If 0 is
pressed after 1, 2, or 5, it multiplies the indicated value by 10.

All pre-set ROIs will be filled in.

The cursor may be moved right or left by using the ARROW keys. When the cursor enters a
ROI, the “cc” (cursor count) will be replaced by “R” and the ROI number and the counts in the
ROI will be displayed.

The function keys operate as follows:

• F1 [COUNT] Allows entry of new parameters (or keep the same ones) and
counts again.

• F2 [T/N] Toggles the counts display between “TOTAL” and “NET” counts.
This applies for individual cursor counts and Regions of Interest.

If background has not been measured, the key will be blank and it
will not be active.

• F3 [ROI] Begins the selection of a Region of Interest.

19-6 MULTICHANNEL ANALYZER OPERATION November 07

CAPINTEC, INC. CAPTUS® 600

To use the ROI Function:

1. Press the F3 [ROI] key – The Normal MCA cursor will become a full size
cursor extending to the full height of the display. This is the ROI cursor.

2. Move the cursor to one side of the desired ROI with the ARROW keys and
press the ENTER key.

3. Move the cursor toward the other side of the ROI with the ARROW keys. The
Region of Interest will be shaded as the ROI grows. You may move the cursor
right and left, but if you move the cursor past a boundary, the unit will revert
back to the normal cursor mode, and you must press the F3 [ROI] key again
to begin an ROI measurement. While shading the ROI, the cursor count
section on the top of the display changes to ROI and displays the Sum Counts
in the ROI.

4. When you have reached the other boundary, press the ENTER key. The ROI
cursor will disappear, but the ROI will remain shaded. The next time you press
an ARROW key, the shading will disappear and the MCA cursor will appear.

5. You may now move the MCA cursor.

• F4 [SC/CR] At any time when viewing the MCA screen, the MCA is either in
Scale Mode or Cursor Mode, the F4 [SC/CR] key toggles between
these two modes.

The MCA defaults to Cursor Mode. This means the number to the
right of the [SC/CR] key determines how many channels the cursor
will jump with each press of the arrow keys.

In Scale Mode, the ARROW keys increase or decrease the vertical
scale. This feature is useful to magnify an area of the display. The
vertical scale will not display less than 100 counts full scale.

To identify if the MCA is in Scale or Cursor Mode, the word
“SCALE” appears on the left of the screen only when in Scale
Mode.

Note: The PRINT [P], F2 [T/N] and F3 [ROI] keys are only active in Cursor Mode. The F4
[SC/CR] key is not active during ROI.

• ENTER key If the ENTER key is pressed any time in Cursor Mode, the cursor
will jump to the nearest peak, found by the automatic peak
searching program, and shade an ROI corresponding to the
expected width of the photo peak, based on the full width-half
maximum (FWHM) measured in the test program.

The ROI is defined as the FWTM (full width–tenth maximum) of a
peak at the energy the automatic peak search has determined to
be the centroid of the peak.

November 07 MULTICHANNEL ANALYZER OPERATION 19-7

CAPINTEC, INC. CAPTUS® 600

Activity of a Nuclide
The feature is only available if Calibration Test has been performed during the current
calendar day.

The counts in a Region of Interest corresponding to a given nuclide can be obtained by
pressing one of the Pre-Set Nuclide keys (Cr51, Co57, Ga67, Tc99m, In111, I131, I123,
I125, Tl201), a USER key which has had a nuclide assigned to it or the NUCL key. After the
NUCL key is pressed, enter the name of the nuclide and press ENTER.

The counts in the ROI are displayed on the top line.

Exiting MCA Measurement
To exit the MCA Results Screen, press the BSP key, and the display will return to the
Parameter Entry Screen.

19-8 MULTICHANNEL ANALYZER OPERATION November 07