(204 days)
Not Found
No
The device description and performance studies focus on standard optical density measurements and data collection, with no mention of AI/ML algorithms for analysis or interpretation. The software is explicitly stated to be for data collection only.
No.
Explanation: This device is an in-vitro diagnostic tool used to measure platelet aggregation in patient samples, which aids in diagnosis. It does not directly provide therapy or treatment to a patient.
Yes.
The "Intended Use / Indications for Use" section explicitly states "The Chrono-log Model 490 4+4 Aggregometer is intended for use for in-vitro diagnostic use for measuring Platelet Aggregation in Platelet Rich Plasma." Additionally, the "Device Description" mentions, "This device is designed to be used in the clinical laboratory as an in vitro diagnostic tool."
No
The device description clearly states it is a physical instrument ("The Chrono-log™ Model 490 4+4 Aggregometer measures platelet function...") that uses light transmission and includes hardware components like sample chambers and photodiodes. While it can connect to a computer with software for data collection, the core device is hardware.
Yes, this device is an IVD (In Vitro Diagnostic).
Here's why:
- Explicit Statement in Intended Use: The "Intended Use / Indications for Use" section clearly states: "The Chrono-log Model 490 4+4 Aggregometer is intended for use for in-vitro diagnostic use for measuring Platelet Aggregation in Platelet Rich Plasma."
- Purpose of the Device: The device measures platelet aggregation and is used to run the Ristocetin Cofactor Assay, which aids in the diagnosis of patients with von Willebrand disease. These are diagnostic purposes performed on biological samples (blood/plasma) outside of the body.
- Clinical Laboratory Setting: The device is intended for use in a "clinical laboratory environment by laboratory technicians," which is a typical setting for IVD devices.
- Use with Cleared Assays: The device is intended for use with "light transmission aggregometry assays cleared for use with the Chrono-log Platelet Aggregometry systems," further indicating its role in diagnostic testing.
- Device Description: The description reinforces its use as an "in vitro diagnostic tool" in the clinical laboratory.
All of these points align with the definition and characteristics of an In Vitro Diagnostic device.
N/A
Intended Use / Indications for Use
The Chrono-log Model 490 4+4 Aggregometer is intended for use for in-vitro diagnostic use for measuring Platelet Aggregation in Platelet Rich Plasma.
This device is intended to be used in a clinical laboratory environment by laboratory technicians.
For use only with light transmission aggregometry assays cleared for use with the Chrono-log Platelet Aggregometry systems.
Product codes (comma separated list FDA assigned to the subject device)
JOZ
Device Description
The Chrono-log™ Model 490 4+4 Aggregometer measures platelet function on patient samples using LTA which measures a change in optical density of platelet rich plasma. The Model 490 4+4 is also used to run the Ristocetin Cofactor Assay to aid in diagnosis of patients with von Willebrand disease. The instrument comes with a starter kit of reagents and supplies. The output of the Model 490 4+4 can be connected to either a strip chart recorder or to a Computer. Software is provided with the computer interface option. The computer interface option is used to collect data only. The computer is not used for diagnosis or treatment and does not have any control over or input into the Model 490 4+4 Aggregometer.
LTA or Born method of platelet aggregation measures the change in optical density of a Platelet Rich Plasma (PRP) sample in comparison to optical density of a Platelet Poor Plasma (PPP) sample. The PRP sample, platelets in a suspension of plasma, is isolated from an anticoagulated blood sample by a relatively low centrifugation. The PPP sample is prepared by centrifuging the blood sample at a relatively high force. The Chrono-log sample chambers are designed so that a beam of infra red light shines through two cuvettes. one containing PRP (the sample) and one containing PPP (the reference). Silicon photodiodes detect the light able to pass through the samples: PRP is arbitrarily considered to be 0% light transmission or 0% aggregation: PPP is considered to be 100% light transmission or 100% aggregation. When a stimulus is added to the cuvette containing PRP and the platelets respond forming aggregates, more light is allowed to pass through the PRP sample. The change in light transmission, recorded over time, shows a trend towards the platelet poor plasma, or 100% light transmission. A graphical tracing of the change in optical density during the course of platelet aggregation is produced either on a strip chart recorder or on a computer using Chrono-log provided software. This device is designed to be used in the clinical laboratory as an in vitro diagnostic tool. The 490 4+4 varies from the predicate devices only in the number of channels.
Mentions image processing
Not Found
Mentions AI, DNN, or ML
Not Found
Input Imaging Modality
Light Transmission Aggregometry (LTA)
Anatomical Site
Not Found
Indicated Patient Age Range
Not Found
Intended User / Care Setting
clinical laboratory environment by laboratory technicians.
Description of the training set, sample size, data source, and annotation protocol
Not Found
Description of the test set, sample size, data source, and annotation protocol
A Comparison study was run to compare the performance of the Model 490 4+4 to the Model 700. Platelet Rich Plasma samples from four normal, healthy, drug free subjects and a subject taking aspirin, a known inhibitor of platelet aggregation by acetylation of the platelet cyclooxygenase pathway. These samples were tested with both instruments.
To demonstrate abnormal results with ADP and Collagen, samples were treated with ticagrelor and GPIIb/IIIa antagonist (Hart Biologicals, Hartlepool, UK), as per manufacturer's instructions. The ticagrelor blocks the P2Y12 ADP-receptor, which reduces the aggregation with ADP. GPIIb/IIIa antagonist blocks the GPIIb/IIIa receptor which reduces aggregation by collagen.
To demonstrate abnormal Ristocetin results, samples were run using deficient vw plasma and lyophilized platelets.
The samples were tested using CHRONO-PAR™ Arachidonic Acid, Epinephrine, Collagen, ADP and Ristocetin. The following concentrations of reagents were run: Arachidonic Acid 0.5 mM, Epinephrine 5uM, Collagen 1ug/mL, Collagen 5ug/mL, ADP 5uM, ADP 10uM, Ristocetin 0.25mg/mL and Ristocetin 1.25 mg/mL. Tests were run using Platelet Rich Plasma samples of both 500uL and 250uL volume.
In total, there were 114 comparison tests using optical aggregation. To demonstrate sample size equivalence, a small subset of tests was used to compare the results for 500uL and 250uL volume samples from a normal donor and a donor taking aspirin. These two sample volumes were run because these are the two recommended sample sizes in the instructions. For both donors, one test with each reagent for both sample sizes was run using the recommended concentrations in the IFU.
Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)
Performance was evaluated through a comparison study.
Sample size: 114 comparison tests using optical aggregation; a small subset of tests was used for sample size equivalence comparing 500uL and 250uL volumes.
Key results: Strong correlation between the Model 490 4+4 and the predicate device, with an R2 Value of 0.9771 for all samples. Strong correlation was also observed when comparing each reagent individually. For normal donors, R2 was 0.9648 (500 µL) and 0.9758 (250 µL). For aspirin donors, R2 was 0.9943 (500 µL) and 0.9871 (250 µL). A Bland Altman Plot showed good agreement with a small bias of -4.56, deemed not clinically significant.
Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)
Coefficient of Variation for various sample groups:
- All Samples: 0.9771
- Normal Samples in 500 µL: 0.9648
- Aspirin Samples in 500 µL: 0.9943
- Normal Samples in 250 µL: 0.9758
- Aspirin Samples in 250 µL: 0.9871
Coefficient of Variation by Reagent:
- Arachidonic Acid: 0.9945
- Epinephrine: 0.9509
- Collagen: 0.9786
- ADP: 0.9421
- Ristocetin: 0.9863
Bias from Bland Altman Plot: -4.56
Predicate Device(s): If the device was cleared using the 510(k) pathway, identify the Predicate Device(s) K/DEN number used to claim substantial equivalence and list them here in a comma separated list exactly as they appear in the text. List the primary predicate first in the list.
Reference Device(s): Identify the Reference Device(s) K/DEN number and list them here in a comma separated list exactly as they appear in the text.
Not Found
Predetermined Change Control Plan (PCCP) - All Relevant Information for the subject device only (e.g. presence / absence, what scope was granted / cleared under the PCCP, any restrictions, etc).
Not Found
§ 864.5700 Automated platelet aggregation system.
(a)
Identification. An automated platelet aggregation system is a device used to determine changes in platelet shape and platelet aggregation following the addition of an aggregating reagent to a platelet-rich plasma.(b)
Classification. Class II (performance standards).
0
Image /page/0/Picture/1 description: The image shows the seal of the U.S. Department of Health and Human Services. The seal is circular and contains the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. In the center of the seal is an abstract image of three faces in profile, stacked on top of each other, resembling a stylized bird.
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
December 2, 2016
Chrono-log Corporation Nicholas J. Veriabo Executive Director 2 West Park Road Havertown, PA 19083-4691
Re: K161329
Trade/Device Name: Chrono-log Platelet Aggregometer, Model 490 4+4 Regulation Number: 21 CFR 864.5700 Regulation Name: Platelet aggregometer Regulatory Class: Class II Product Code: JOZ Dated: November 2, 2016 Received: November 4, 2016
Dear Mr. Veriabo:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of
1
medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely,
Leonthena R. Carrington -S
Leonthena R. Carrington, MS. MBA. MT(ASCP) Director
Division of Immunology and Hematology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health
2
Indications for Use
510(k) Number (if known) K161329
Device Name
Chrono-log Platelet Aggregometer, Model 490 4+4
Indications for Use (Describe)
The Chrono-log Model 490 4+4 Aggregometer is intended for use for in-vitro diagnostic use for measuring Platelet Aggregation in Platelet Rich Plasma.
This device is intended to be used in a clinical laboratory environment by laboratory technicians.
For use only with light transmission aggregometry assays cleared for use with the Chrono-log Platelet Aggregometry systems.
Type of Use (Select one or both, as applicable)
| Depreciating Use (Part 21 CFR 606 Subpart D) |
|---|
| One-Time Use (Part 21 CFR 606 Subpart C) |
Prescription Use (Part 21 CFR 801 Subpart D)
| | Over-The-Counter Use (21 CFR 801 Subpart C)
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3
11. 510(k) Summary
Device: Chrono-log™ Platelet Aggregometer, Model 490 4+4
Date: March 17, 2016
Submitted by: Chrono-log Corp., 2 West Park Rd., Havertown, PA 19083
Contact: Nicholas J. Veriabo (610) 853-1130
Name of Device:
Trade/Proprietary Name - Chrono-log™ Platelet Aggregometer Model 490 4+4
Common/Usual Name - Platelet Aggregometer
Classification Name - System, Automatic Platelet Aggregation 21CFR 864.5700
Regulatory Class – Class II
Product Code – JOZ
510(k) Review Panel - Hematology
Predicate Device:
Trade/Proprietary Name - Chrono-log™ Whole Blood Lumi-Aggregometer Model 700
Common/Usual Name - Platelet Aggregometer, Whole Blood Aggregometer, Lumi-Aggregometer
Classification Name - System, Automatic Platelet Aggregation 21CFR 864.5700
Regulatory Class – Class II
Product Code – JOZ
510(k) Review Panel - Hematology
4
11.1 Device Description:
The Chrono-log™ Model 490 4+4 Aggregometer measures platelet function on patient samples using LTA which measures a change in optical density of platelet rich plasma. The Model 490 4+4 is also used to run the Ristocetin Cofactor Assay to aid in diagnosis of patients with von Willebrand disease. The instrument comes with a starter kit of reagents and supplies. The output of the Model 490 4+4 can be connected to either a strip chart recorder or to a Computer. Software is provided with the computer interface option. The computer interface option is used to collect data only. The computer is not used for diagnosis or treatment and does not have any control over or input into the Model 490 4+4 Aggregometer.
LTA or Born method of platelet aggregation measures the change in optical density of a Platelet Rich Plasma (PRP) sample in comparison to optical density of a Platelet Poor Plasma (PPP) sample. The PRP sample, platelets in a suspension of plasma, is isolated from an anticoagulated blood sample by a relatively low centrifugation. The PPP sample is prepared by centrifuging the blood sample at a relatively high force. The Chrono-log sample chambers are designed so that a beam of infra red light shines through two cuvettes. one containing PRP (the sample) and one containing PPP (the reference). Silicon photodiodes detect the light able to pass through the samples: PRP is arbitrarily considered to be 0% light transmission or 0% aggregation: PPP is considered to be 100% light transmission or 100% aggregation. When a stimulus is added to the cuvette containing PRP and the platelets respond forming aggregates, more light is allowed to pass through the PRP sample. The change in light transmission, recorded over time, shows a trend towards the platelet poor plasma, or 100% light transmission. A graphical tracing of the change in optical density during the course of platelet aggregation is produced either on a strip chart recorder or on a computer using Chrono-log provided software. This device is designed to be used in the clinical laboratory as an in vitro diagnostic tool. The 490 4+4 varies from the predicate devices only in the number of channels.
11.2 Intended Use:
The Chrono-log Model 490 4+4 Aggregometer is intended for use for in-vitro diagnostic use for measuring platelet aggregation in platelet rich plasma. This device is intended to be used in a clinical laboratory environment by laboratory technicians. For use only with light transmission aggregometry assays cleared for use with the Chrono-log™ Platelet Aggregometry systems.
11.3 Technical Description:
The Chrono-log™ Model 490 4+4 Aggregometer is an instrument used in the Laboratory for the determination of Platelet Aggregation in samples of PRP. The 490 4+4 is a modified Model 700. Substantial equivalency between the Model 490 4+4 and the Model 700 (K050265) currently in commercial distribution by Chrono-log Corp is claimed.
5
The fundamental scientific technology of the modified device was unchanged. The energy type is the same. Environmental specifications are the same. Performance specifications are the same as the optical method of the predicate device. The ergonomics of the user interface is the same and the firmware is the same.
The critical components of the Model 490 4+4 are exactly the same as the predicate device. The circuits that drive these components are the same as the circuits used in the Model 700. Due to various parts in the predicate device becoming obsolete, some circuit parts were upgraded in the Model 490 4+4. The chart on the following page gives a detailed description of the component differences between the Model 490 4+4 and the Model 700.
The chassis has also been redesigned to accommodate four channels. The front panel for both use a Liquid Crystal Display (LCD) for displaying Temperature and Stirring Speed. Both instruments have front panel controls which are tactile membrane switches.
The output of the Model 490 4+4 can be connected to either a strip chart recorder or to a Computer. Chrono-log provides software for the computer interface option as an accessory. The computer interface option is used to collect data and is not used for diagnosis or treatment and does not have any control over or input into the Model 490 4+4 Aggregometer.
| 490 4+4 Component change | ||||||
|---|---|---|---|---|---|---|
| Component | Functionality | Description of change | Material | |||
| Change | Impact of change | Mitigation | ||||
| Heater | ||||||
| Block | Holds sample | |||||
| Heats sample | Heater Block was made | |||||
| smaller. Remove holes for | ||||||
| luminescence measurements | None | Minimal - LED and | ||||
| photodiodes are | ||||||
| closer to sample | Verification testing | |||||
| was performed by | ||||||
| measuring optical | ||||||
| density samples and | ||||||
| recording voltage | ||||||
| readings. All samples | ||||||
| measured to | ||||||
| specifications. | ||||||
| Photodiode | ||||||
| Amplifier | Measures the | |||||
| amount of light | ||||||
| shining through | ||||||
| the samples | Resistors R1, R2, R3 & R4 | |||||
| were changed from 20MΩ to | ||||||
| 10MΩ to reduce the gain on | ||||||
| the amplifier. A lower gain | ||||||
| was needed because the | ||||||
| heater blocks are closer. | None | No known impact. | ||||
| The output voltage | ||||||
| is the same for | ||||||
| various optical | ||||||
| density | Verification testing | |||||
| was performed by | ||||||
| measuring optical | ||||||
| density samples and | ||||||
| recording voltage | ||||||
| readings. All samples | ||||||
| measured to | ||||||
| specifications. | ||||||
| Heater | ||||||
| Control | ||||||
| Board | Heats the | |||||
| heater blocks | ||||||
| and has the | ||||||
| Door switch for | ||||||
| Luminescence | The following parts are | |||||
| removed: U5, C8, C11, D1, D2, | ||||||
| D3, D4, D5, D6, D7. These | ||||||
| components are used for | ||||||
| luminescence in the Model |
- In the Model 490 4+4
there isn't a luminescence | None | Luminescence
feature removed.
Cannot measure
ATP release, which
is within the design
specifications. | Verification not
needed for the
removal of the
Luminescence
feature. | |
| | | feature. These components
are removed to reduced costs. | | | | |
| Analog
Control
Board | Processes the
output from
the detection
devices. | The following parts were
removed U10, U11, C10, C11,
R17, R18, R19, R20, R21, R26,
P1 & P2. These components
are for the luminescence and
the selection between optical
and Impedance methods in
the Model 700. In the Model
490 4+4, the luminescence
and impedance features are
not used, so these
components were removed to
reduce costs. | None | Luminescence and
Impedance features
removed. Cannot
measure ATP
release or
Impedance
aggregation, which
is within the design
specifications. | Verification not
needed for the
removal of the
Luminescence and
Impedance features. | |
| Switch
Circuit on
Heater
Block Board | Turns power on
to PMT when
heater block
door is closed,
shuts off power
when door is
opened. The
PMT is used for
luminescence
measurement
of ATP release. | The following parts are
removed U1, C1, C2, R2, R4,
R5, R6, RL1, Con 2, Con 3, and
Con 4,. All components above
are for the door switch circuit
used for luminescence in the
Model 700. In the Model 490
4+4 there isn't a luminescence
feature, so this circuit is not
needed. These components
are removed to reduce cost. | None | Luminescence
feature removed.
Cannot measure
ATP release, which
is within the design
specifications. | Verification not
needed for the
removal of the
Luminescence
feature. | |
| Heater
block
circuit | Heats the
heater blocks
to the
temperature
set on the front
panel. | R2 was removed and R1
resistance was increased. The
circuits for heating the block
are the same except the
Model 700 uses two resistors
to heat the block where as the
Model 490 4+4 needs only 1
resistor to heat the smaller
block. This is why R2 was
removed. The value of R1 was
increased because less
current is needed to heat
smaller block size in the
Model 490 4+4. | None | Minimal - The
heater block
temperature is
maintained at the
temperature set on
the front panel,
usually 37°C. | Verification testing
was performed by
measuring the
temperature of the
blocks for every
possible setting. All
temperature settings
tested to
specifications. | |
| Four Motor
Driver
Board | Drives the
stirring motors.
Controls the
stirring motors
speed.
Monitors the
motor speed. | The combination of U2, R1,
R2, R3, R4, C8 and C9 on
Drawing 6811 replaces
components U2, T1, T2, T3,
T4, D1, D2, D3, D4, D5, C1, C2,
C3, C4, C5, C6, C7, R1, R2, R3,
R4, R5, R6, R7, R8, R9, R10,
R11, R12, R13, R14 and R15
on Drawing 6597 and also
replaces U3, Q 1, R1, R2, R3,
C10 and C11 on Drawing - The rest of the circuit is
the same. | None | Minimal- Stirrer
driver operates as a
Phase-locked circuit
keeping the stirrer
speed locked to the
reference
frequency provided
by a
Microcontroller.
Both circuits
(original and
revised) accomplish
this and are
functionally equal. | Verification testing
was performed by
measuring the
frequency of the
signals and
revolution rate of the
motors. Fault
conditions were
induced to test the
error checking
feature. All
conditions tested to
specifications. | |
6
7
11.4 Performance:
Design control activities conforming to 21.CFR 820.30 were implemented in the device modification process. As demonstrated by risk analysis and by verification and validation activities, no questions of safety and effectiveness were raised. Verification and validation activities were performed and the results show conformance with predetermined acceptance criteria. These nonclinical tests suggest that the modified device is substantially equivalent to the predicate device.
A Comparison study was run to compare the performance of the Model 490 4+4 to the Model 700. Platelet Rich Plasma samples from four normal, healthy, drug free subjects and a subject taking aspirin, a known inhibitor of platelet aggregation by acetylation of the platelet cyclooxygenase pathway. These samples were tested with both instruments.
To demonstrate abnormal results with ADP and Collagen, samples were treated with ticagrelor and GPIIb/IIIa antagonist (Hart Biologicals, Hartlepool, UK), as per manufacturer's instructions. The ticagrelor blocks the P2Y12 ADP-receptor, which reduces the aggregation with ADP. GPIIb/IIIa antagonist blocks the GPIIb/IIIa receptor which reduces aggregation by collagen.
To demonstrate abnormal Ristocetin results, samples were run using deficient vw plasma and lyophilized platelets.
The samples were tested using CHRONO-PAR™ Arachidonic Acid, Epinephrine, Collagen, ADP and Ristocetin. The following concentrations of reagents were run: Arachidonic Acid 0.5 mM, Epinephrine 5uM, Collagen 1ug/mL, Collagen 5ug/mL, ADP 5uM, ADP 10uM, Ristocetin 0.25mg/mL and Ristocetin 1.25 mg/mL. Tests were run using Platelet Rich Plasma samples of both 500uL and 250uL volume.
In total, there were 114 comparison tests using optical aggregation. To demonstrate sample size equivalence, a small subset of tests was used to compare the results for 500uL and 250uL volume samples from a normal donor and a donor taking aspirin. These two sample volumes were run because these are the two recommended sample
8
sizes in the instructions. For both donors, one test with each reagent for both sample sizes was run using the recommended concentrations in the IFU.
The Tables below show the correlation between the Model 490 4+4 and the Model 700.
ALL SAMPLES
| No. of Samples | Coefficient of Variation |
|---|---|
| 114 | 0.9771 |
NORMAL SAMPLES IN 500 µL
| No. of Samples | Coefficient of Variation |
|---|---|
| 8 | 0.9648 |
ASPIRIN SAMPLES IN 500 µL
| No. of Samples | Coefficient of Variation |
|---|---|
| 8 | 0.9943 |
NORMAL SAMPLES IN 250 µL
| No. of Samples | Coefficient of Variation |
|---|---|
| 8 | 0.9758 |
ASPIRIN SAMPLES IN 250 µL
| No. of Samples | Coefficient of Variation |
|---|---|
| 8 | 0.9871 |
When comparing the results of the 490 4+4 to the predicate device with each individual reagent, there is a strong correlation with each reagent.
| Reagent | Coefficient of Variation |
|---|---|
| Arachidonic Acid | 0.9945 |
| Epinephrine | 0.9509 |
| Collagen | 0.9786 |
| ADP | 0.9421 |
| Ristocetin | 0.9863 |
9
11.5 Conclusion:
The results of the study show strong correlation between the Model 490 4+4 and the predicate device. The R2 Value of all samples run is 0.9771. There is also a strong correlation when comparing each reagent. In a subset of samples, values for the two recommended sample sizes were compared and strong correlation was found with the normal donors and donors on aspirin. Normal donors gave an R2 result of 0.9648 for the 500 uL samples and 0.9758 for the 250 uL samples. Aspirin donors gave an R2 result of 0.9943 for the 500 µL samples and 0.9871 for the 250 µL samples.
An agreement analysis using a Bland Altman Plot showed good agreement between the 490 4+4 and the predicate device. There is a small bias of -4.56 which is not clinically significant for this assay. The Bland Altman Plot shows agreement and the 2SD cut-off is not beyond what is historically seen with platelet aggregation.12
Since the assay is the same for the 490 4+4 and the predicate device, the aim is to show equivalence results for the two devices. The enclosed data supports the claim of substantial equivalence.
- Riess et al: Clinical Evaluation of Platelet Aggregation in Whole Human Blood 1. American Journal of Clinical Pathology (1986) 85 (1): 50-56
-
- Alshameeri et al (1995): Comparisons of Platelet Aggregation in Platelet Rich Plasma and Whole Blood. Disorders of Thrombosis & Hemostasis, Abstract.