(193 days)
The Chrono-log WBA, Model 591A/592A is intended for determination of platelet function in a whole blood specimen, using ADP, Collagen and Ristocetin reagents.
For Platelet Function testing of Whole Blood specimens using Impedance Aggregometry. For Prescription Use.
The Chrono-log WBA, Model 591A/592A uses electrical impedance to measure platelet aggregation in a whole blood sample. The Impedance is measured using a Disposable electrode with two precious metal pins. A small voltage is applies across these two pins. When the electrode is placed into a diluted whole blood specimen and a monolayer is formed around the two pins. In the absence of an agonist, the platelet build-up stabilizes and a baseline is established. When an agonist is added to the specimen, the platelets begin to aggregate and collect on the electrode pins causing a change in impedance. The change of impedance is directly proportional to the amount of Aggregation in the specimen. This change of impedance is displayed on a front panel readout. The instrument has an analog output which produces an aggregation curve when connected to a strip chart recorder or AGGRO/LINK interface. Model 591 A is a single channel version; Model 592A is the duel channel version.
This document describes the performance testing of the Chrono-log Whole Blood Aggregometer (WBA), Model 591A/592A, and its substantial equivalence to the predicate device, Model 591/592, with the primary difference being the introduction of disposable electrodes.
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria were primarily based on demonstrating substantial equivalence to the predicate device through correlation, statistical significance, and the ability to detect aggregation changes and patient conditions similarly. New normal ranges were also established.
| Acceptance Criteria / Performance Metric | Predicate Device (Reusable Electrodes) | New Device (Disposable Electrodes) | Reported Performance (New vs. Predicate) | Outcome / Acceptance |
|---|---|---|---|---|
| Overall Correlation (Pearson's R) | N/A | N/A | R = 0.84 (250 samples) | Met |
| Paired t-test | N/A | N/A | P < 0.0001 (250 samples) | Met |
| Reproducibility (Collagen 2μg/mL) | Mean: 13.9 ± 3.0 Ω | Mean: 14.2 ± 2.2 Ω | P = 0.47, R = 0.24 (n=50) | Comparable |
| Reproducibility (Collagen 5μg/mL) | Mean: 17.7 ± 2.8 Ω | Mean: 16.6 ± 2.3 Ω | P = 0.03, R = 0.04 (n=50) | Comparable |
| Reproducibility (ADP 20μM) | Mean: 9.94 ± 3.4 Ω | Mean: 13.2 ± 2.5 Ω | P < 0.01, R = 0.61* (n=50) | Comparable |
| Ristocetin (vWD detection, low dose) | Reduced/absent results for all patients | Reduced/absent results for all patients | Expected for all vWD patients (8/8 for RP, 7/8 for DP showed reduced results) | Met |
| Ristocetin (vWD detection, high dose) | Reduced/absent for vWD patients | Reduced/absent for vWD patients | Better performance for DP in identifying vWD | Met |
| Detecting changes with platelet count (Whole Blood) | Positive correlation (R^2 = 0.4491) | Positive correlation (R^2 = 0.9037) | Both methods demonstrated ability to detect changes | Met |
| Detecting changes with platelet count (PRP) | Positive correlation (R^2 = 0.9064) | Positive correlation (R^2 = 0.8512) | Both methods demonstrated ability to detect changes | Met |
| Normal Range (Collagen 5μg/mL) | 16-29 Ω | N/A | New established: 12-23 Ω | Established / Close to predicate |
| Normal Range (Collagen 2μg/mL) | N/A | N/A | New established: 10-21 Ω | Established |
| Normal Range (ADP 20μM) | 9-14 Ω (for 10μM) | N/A | New established: 9-18 Ω | Established / Close to predicate |
| Normal Range (Ristocetin 0.4mg/mL) | 17-38 Ω (for 1mg/mL) | N/A | New established: >5 Ω | Established / Close to predicate |
Note on R for ADP 20μM: The Pearson's R value of 0.61 is marked with an asterisk indicating p<0.05, suggesting a statistically significant correlation despite the moderate value. The p<0.01 for the paired t-test indicates a statistically significant difference between the means, but the purpose of this study is primarily to show comparable performance and the ability to detect aggregation, not identical readings.
2. Sample Size Used for the Test Set and Data Provenance
- Overall Correlation Study: 250 samples.
- Reproducibility, Precision, and Accuracy (Collagen, ADP): n=50 for each agonist concentration.
- Ristocetin Studies (Normal & vWD Patients): n=12 normal donors, n=8 vWD patients.
- Platelet Count Correlation (Whole Blood & PRP): Specific numbers for each data point are provided in the tables (e.g., 13 data points for Whole Blood, 9 for PRP), but an overall sample size for these specific correlation analyses is not explicitly stated as a single number.
- Data Provenance: The subjects were "normal, healthy, drug free subjects" and "patients known to have von Willebrands Disease (vWD)". The country of origin is not specified but implicitly assumed to be the United States, given the FDA filing. The data is prospective, as it was collected for the purpose of this 510(k) submission to compare the new device with the predicate.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts
The concept of "ground truth" in this context is based on the measurements obtained from the predicate device (Chrono-log Whole Blood Aggregometer Model 591/592) and established medical understanding of platelet aggregation in normal individuals and those with conditions like von Willebrand's Disease. No external "experts" were explicitly used to establish a separate ground truth for the test set beyond the predicate device's readings and known clinical characteristics of patient groups.
4. Adjudication Method for the Test Set
No explicit adjudication method is mentioned. The comparison is objective, based on direct readings from two different devices (new vs. predicate) using the same blood samples and reagents. Statistical tests (Pearson Correlation, Paired t-test) were used to analyze the agreement and differences between the two devices.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This study focuses on the performance of the device itself (new electrode vs. old electrode) rather than how human readers (users) interact with or interpret the results, or the impact of AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, the study is essentially a standalone performance assessment of the new device (model 591A/592A with disposable electrodes) compared to the predicate device (model 591/592 with reusable electrodes). The output is a numerical measurement (aggregation in ohms), and the performance comparison is based on these objective measurements, demonstrating the device's inherent functionality.
7. The Type of Ground Truth Used
The ground truth is primarily:
- Predicate Device Performance: The measurements obtained from the predicate Chrono-log Whole Blood Aggregometer (Model 591/592) served as the primary reference for comparison. The new device was expected to produce "comparable results."
- Known Physiological Responses: The expected aggregation patterns in "normal, healthy, drug-free subjects" and patients with "von Willebrand's Disease (vWD)" were used as a clinical ground truth for assessing the device's ability to differentiate these conditions.
- Clinical Understanding of Platelet Count Impact: The knowledge that platelet aggregation is influenced by platelet count (e.g., reduced aggregation below 50,000/uL) served as a physiological ground truth.
8. The Sample Size for the Training Set
No specific "training set" is mentioned in the context of machine learning. This device operates based on electrical impedance principles, not a machine learning algorithm that requires a training set. The data presented demonstrates the device's performance directly.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no machine learning model or "training set" in the context of this device's validation.
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11. 510(k) Summary
Device: Chrono-log Whole Blood Aggregometer (WBA), Model 591A/592A
Date: September 5, 2003
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 Whole Blood Aggregometer (WBA), Model 591 A/592 A Common/Usual Name - Chrono-log Whole Blood Aggregometer Classification Name - System, Automatic Platelet Aggregation
After examining the tests data included in this application, we have found the Chrono-log Whole Blood Aggregometer with Disposable Electrodes (WBA), Model 591A/592A to be substantially equivalent to Chrono-log Whole Blood Aggregometer ( WBA) Model 591/592 (K962426).
11.1 Device Description:
The Chrono-log WBA, Model 591A/592A uses electrical impedance to measure platelet aggregation in a whole blood sample. The Impedance is measured using a Disposable electrode with two precious metal pins. A small voltage is applies across these two pins. When the electrode is placed into a diluted whole blood specimen and a monolayer is formed around the two pins. In the absence of an agonist, the platelet build-up stabilizes and a baseline is established. When an agonist is added to the specimen, the platelets begin to aggregate and collect on the electrode pins causing a change in impedance. The change of impedance is directly proportional to the amount of Aggregation in the specimen. This change of impedance is displayed on a front panel readout. The instrument has an analog output which produces an aggregation curve when connected to a strip chart recorder or AGGRO/LINK interface. Model 591 A is a single channel version; Model 592A is the duel channel version.
11.2 Intended Use:
The Chrono-log WBA, Model 591A/592A is intended for determination of platelet function in a whole blood specimen, using ADP, Collagen and Ristocetin reagents.
11.3 Technical Description:
The Chrono-log Whole Blood Aggregometer with Disposable Electrodes (WBA), Model 591 A/592A is the same device as the predicated device the Chrono-log Whole Blood Aggregometer ( WBA) Model 591/592. Both devices use Impedance method of platelet
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aggregation detection as described in Device Description. Both Devices have the same chassis design, automatic baseline setting, and front panel digital readout and the use the same internal circuit boards. The only new feature of the Model 591 A/592A is the Disposable Electrode.
11.4 Performance:
The performance of the Chrono-log WBA Model 591A/592A was compared to the Chrono-log Whole Blood Aggregometer Model 591/592 using normal, healthy, drug free subjects. The samples were tested using Chrono-log Collagen, ADP, and Ristocetin Reagents. The following concentrations of reagents were run: Collagen 2ug/mL and 5ug/mL, ADP 1uM and 20uM and 1.0 mM; Ristocetin 0.15mg/mL, 0.15mg/mL and 1.0mg/mL. In all over 300 test were run on each type of electrodes. However, due to the fact that the Disposable Electrodes were sensitive to the high dose of Ristocetin, this reagent was eliminated from these calculations and are addressed separately. The results are expressed as aggregation in ohms obtained with the concentrations of agonist stated previously.
Table 11-1 shows the correlation between the Disposable and re-usable electrodes:
TABLE 11-1
| No. of Samples | Pearson Correlation | Paired t test |
|---|---|---|
| 250 | R = 0.84 | P < 0.0001 |
The Figure 11.1 is a scattergram showing the data distribution for the correlation Study.
Image /page/1/Figure/7 description: The image is a scatter plot titled "Comparison Scatter Graph with Regression Line Disposable Probe (DP) vs Reusable Probe (RP)". The x-axis is labeled "RP Results in Ohms" and ranges from 0 to 25. The y-axis is labeled "DP Results in ohms" and ranges from 0 to 25. The scatter plot shows a positive correlation between the disposable probe and reusable probe results, with a regression line drawn through the data.
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Test reproducibility, precision, and accuracy data was obtained to determine equivalence between the Disposable Electrode and the Reusable Electrode. Specimens were tested with several agonists, results are shown in Table 11-2 below. .
| Agonist | DisposableProbe (Ω) | Re-usableProbe (Ω) | P value forpaired t test | Pearson's Rvalue |
|---|---|---|---|---|
| Collagen 2μg/mL | 14.2 ± 2.2 | 13.9 ± 3.0 | 0.47 | 0.24 |
| Collagen 5μg/mL | 16.6 ± 2.3 | 17.7 ± 2.8 | 0.03 | 0.04 |
| ADP 20μM | 13.2 ± 2.5 | 9.94 ± 3.4 | <0.01 | 0.61* |
*p<0.05
Table 11-2. Whole Blood response to Various Agonists. Data are mean ± SD (n=50).
From our initial data using Ristocetin as the reagent, we determined that the disposable electrodes were more sensitive to Aggregation with Ristocetin than to the reusable electrodes. Further tests were run to determine if a lower concentration of reagent would yield a more comparable result to the reusable electrode using the standard Ristocetin concentration. These tests were run on normal donors and patients known to have von Willebrands Disease (vWD).
Two concentrations of Ristocetin, a low and high dose, were run with both the reusable and disposable electrodes. The low dose Ristocetin was 0.15 mg/mL for both types of electrodes. The higher dose of Ristocetin was 1mg/mL for reusable electrodes and 0.4 mg/mL for disposable electrodes. The Ristocetin dose was adjusted to 0.4 mg/mL to compensate for the high sensitivity seen with the disposable electrodes. The expectation was to see little or no Aggregation for the low dose Ristocetin in both the normal donors and the vWD Patients. With the high dose Ristocetin, we expected to see normal results (>5 Ω) with the normal patients and reduced (<6 (2) or no aggregation with the vWD patients.
The results in Table 11.3 show that for normal patients, all results (N=12) were reduced or absent of Aggregation with the low dose Ristocetin. With the high dose Ristocetin, 11 of the 12 normal donors gave normal Aggregation with both methods. A different donor gave the reduced response for each type, leading us to believe that these were outliers.
| Ristocetin Aggregation Normals | Ristocetin Aggregation Normals | ||
|---|---|---|---|
| RP 0.15 mg/mL | DP 0.15 mg/mL | RP 1.0 mg/ml | DP 0.4 mg/ml |
| 0 | 3 | 9 | 8 |
| 0 | 3 | 20 | 18 |
| 0 | 2 | 22 | 10 |
| 0 | 1 | 25 | 65 |
| 0 | 1 | 14 | 6 |
| 0 | 0 | 11 | 20 |
| 0 | 0 | 17 | 5 |
| 0 | 0 | 2 | 7 |
| 0 | 0 | 8 | 54 |
| 0 | 1 | 9 | 37 |
| 0 | 1 | 9 | 29 |
| 0 | 2 | 7 | 7 |
Image /page/2/Figure/8 description: The image shows the words "Table 11.3" in bold font. The word "Table" is followed by the number 11, a period, and the number 3. This appears to be a table heading.
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The results in Table 11.4 are vWD patients. vWD Patients are known to give lower than normal aggregation with Ristocein. The low dose Ristocetin gave reduced or absent results as expected for all patients. Six of the eight vWD patients gave reduced results with the reusable electrodes and seven of the eight vWD patients gave reduced results with the disposable electrodes.
| Ristocetin Aggregation vW Patients | Ristocetin Aggregation vW Patients | ||
|---|---|---|---|
| RP 0.15 mg/mL | DP 0.15 mg/mL | RP 1.0 mg/ml | DP 0.4 mg/ml |
| 0 | 0 | 3 | 0 |
| 0 | 0 | 12 | 4 |
| 0 | 1 | 25 | 19 |
| 0 | 1 | 1 | 0 |
| 0 | 2 | 2 | 2 |
| 0 | 0 | 4 | 0 |
| 2 | 0 | 0 | 0 |
| 0 | 0 | 0 | 0 |
Table 11.4
In this study, the disposable electrodes performed better than the reusable electrodes for identifying donors with von Willebrands Disease using high and low dose Ristocetin.
Another way to demonstrate substantial equivalency is to show that the new device can detect increasing and decreasing amount of aggregation similar to the predicate device. With the Impedance Method of platelet aggregation, when aggregation takes place in the sample, the platelets stick to the electrode wires or pins on the disposable electrodes causing an increase in impedance as measured by the Aggregometer. Increased amounts of platelet build-up (aggregation) produce a greater impedance result; a reduced amount of aggregation produces a lower impedance result. One of the factors that influence platelet aggregation in whole blood is platelet count. Specifically, a significant reduction in aggregation is seen with platelet counts below 50,000/uL. " Because there is only a small number of platelets in the sample (platelet count), the total amount of aggregation will be less than a sample with a normal amount of platelets. This has been demonstrated in prior studies using impedance aggregation.2
We demonstrate that both the Model 591 A/592A with the disposable electrodes and the Model 591/592 with the reusable electrodes were able to detect the changes in Aggregation in relation to platelet count. This was done in both Whole Blood and PRP. Platelet counts below 50,000/uL gave results below the normal range. Table 11.4 shows the values at various platelet counts with disposable and reusable electrodes in Whole Blood. Table 11.5 shows the values at various platelet counts with disposable and reusable electrodes in PRP.
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| Whole Blood | ||
|---|---|---|
| Platelet Count* | DP | RP |
| 300 | 30 | 18 |
| 294 | 25 | 14 |
| 164 | 15 | 21 |
| 144 | 19 | 21 |
| 73 | 15 | 18 |
| 64 | 13 | 19 |
| 34 | 7 | 6 |
| 32 | 7 | 8 |
| 21 | 5 | 3 |
| 18 | 9 | 8 |
| 10 | 4 | 3 |
| 1 | 1 | 0 |
| 0 | 2 | 0 |
| PRP | ||
|---|---|---|
| Platelet Count* | DP | RP |
| 181 | 19 | 22 |
| 104 | 13 | 17 |
| 104 | 17 | 16 |
| 58 | 8 | 9 |
| 31 | 7 | 3 |
| 27 | 10 | 9 |
| 15 | 5 | 4 |
| 15 | 3 | 1 |
| 4 | 1 | 0 |
Table 11.5
- X 10*/uL Table 11.4
Figures 11.2, 11.3, 11.4 and 11.5 are scatter graphs with liner regression lines showing the relationship between the results and platelet count.
Image /page/4/Figure/5 description: The image is a scatter plot titled "DP vs PLT CNT in Whole Blood". The x-axis is labeled "Platelet Count" and ranges from 0 to 350. The y-axis is labeled "DP in ohms" and ranges from 0 to 35. The plot shows a positive correlation between DP and platelet count, with an R-squared value of 0.9037.
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Image /page/5/Figure/0 description: The image is a scatter plot titled "RP vs PLT CNT in Whole Blood". The x-axis is labeled "Platelet Count" and ranges from 0 to 350. The y-axis is labeled "RP In Ohms" and ranges from 0 to 25. The scatter plot shows a positive correlation between RP and PLT CNT, with an R-squared value of 0.4491.
Image /page/5/Figure/1 description: The image shows the text "FIGURE 11.3" in a bold, sans-serif font. The word "FIGURE" is in all capital letters, followed by the number "11.3". The text is likely a figure label from a document or publication.
Image /page/5/Figure/2 description: The image is a scatter plot titled "DP vs Platelet Count Platelet Rich Plasma". The x-axis is labeled "Platelet Count" and ranges from 0 to 200. The y-axis is labeled "DP in Ohms" and ranges from 0 to 25. The plot shows a positive correlation between platelet count and DP in Ohms, with an R-squared value of 0.8512.
FIGURE 11.4
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Image /page/6/Figure/0 description: The image is a scatter plot titled "RP vs Platelet Count in Platelet rich plasma". The x-axis is labeled "Platelet Count", ranging from 0 to 200, and the y-axis is labeled "RP in Ohms", ranging from 0 to 30. The plot shows a positive correlation between RP and platelet count, with an R-squared value of 0.9064, indicating a strong linear relationship.
FIGURE 11.5
These graphs show a strong relationship between platelet count and each instrument in both Whole Blood and PRP as marked, demonstrating that the Model 591A/592A can detect lesser and greater amounts of platelet aggregation with similar results as are seen in the Model 591/592.
The physical differences between the reusable and disposable electrodes caused a slight shift in the normal range. We establish a new normal range to reflect this shift. The normal ranges established in this study for the Model 591A/592A are as follows:
| Collagen | 5μg/mL | 12-23 |
|---|---|---|
| Collagen | 2μg/mL | 10-21 |
| ADP | 20μM | 9-18 |
| Ristocetin | 0.4mg/mL | >5Ω |
The previously established normal ranges for the Model 591/592 are as follows:
| Collagen | 5 µg/mL | 16-29 |
|---|---|---|
| ADP | 10 µM | 9-14 |
| Ristocetin | 1 mg/mL | 17-38 |
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Although the two sets of normal ranges are not exact, the normals are close to the previously established normal range in both value and range.
We analyzed the results of the two methods using the Bland-Altman comparison plot using reagent concentrations of 2 ug/mL Collagen, 5 ug/mL Collagen and 20uM ADP. Figures 11.6, 11.7 and 11.8 are the plot difference in ohms and the plot difference in percent for the three reagent concentrations.
Image /page/7/Figure/2 description: The image shows two Bland & Altman plots for 2 ug/mL Collagen. The left plot compares results in Ohms, while the right plot compares results in Percent. In the left plot, the mean is -0.3, and the +1.96 SD and -1.96 SD are 6.1 and -6.8, respectively. In the right plot, the mean is -3.8, and the +1.96 SD and -1.96 SD are 43.8 and -51.5, respectively.
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Image /page/8/Figure/0 description: The image shows two Bland & Altman plots for 5 ug/mL Collagen. The left plot compares the result in Ohms, while the right plot compares the result in Percent. The left plot shows the average of RP and DP on the x-axis and RP-DP on the y-axis, with a mean of 1.1 and a +1.96 SD of 8.0 and a -1.96 SD of -5.8. The right plot shows the average of RP and DP on the x-axis and (RP-DP)/Average % on the y-axis, with a mean of 5.9 and a +1.96 SD of 46.4 and a -1.96 SD of -34.6.
FIGURE 11.7
Image /page/8/Figure/2 description: The image shows two Bland & Altman plots for 20uM ADP. The plot on the left compares the results in Ohms, while the plot on the right compares the results in percent. The left plot shows the mean at -3.2, +1.96 SD at 2.0, and -1.96 SD at -8.3. The right plot shows the mean at -30.8, +1.96 SD at 31.3, and -1.96 SD at -92.9.
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Examining the graphs, we see that there is a wide range for the 2SD cut-off; however, this is not beyond what is historically seen with platelet aggregation in whole blood on normal subjects. Since these donors are all normal subjects, we are able to establish a normal range from the data. As stated previously in this report, the normal range is close in value and range to the normal range established for the Model 591/592.
The results of these tests indicate that the two models of Whole Blood Aggregometer give comparable results and raise no new issues of safety or effectiveness.
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Public Health Service
Image /page/10/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized eagle or bird-like symbol with three curved lines representing its wings or body. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" is arranged in a circular fashion around the symbol.
Food and Drug Administration 2098 Gaither Road Rockville MD 20850
APR - 2 2004
Mr. Nicholas J. Verabo Executive Director Chrono-Log Corp. 2 West Park Rd. Havertown, PA 19083
K032951 Re:
Trade/Device Name: Chrono-Log Whole Blood Aggregometer (WBA) Model 591A/592A Regulation Number: 21 CFR 864.5700 Regulation Name: Automated platelet aggregation system Regulatory Class: Class II Product Code: JOZ Dated: February 10, 2004 Received: February 11, 2004
Dear Mr. Verabo
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.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in Title 21, Code of Federal Regulations (CFR), Parts 800 to 895. 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); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820).
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If you desire specific information about the application of labeling requirements to your device, or questions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (301) 594-3084. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.
Sincerely yours,
Joseph L. Aralett
Joseph L. Hackett, Ph.D. Acting Director Division of Immunology and Hematology Devices Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health
Enclosure
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6. INDICATIONS FOR USE
Chrono-log Whole Blood Aggregometer (WBA) Device Name: Model 591A/592A
For Platelet Function testing of Whole Indications for Use: Blood specimens using Impedance Aggregometry.
For Prescription Use✓
Souphim Busteri
Division Sign-Off
Division Sign-Off
Office of In Vitro Diagnostic Device Evaluation and Safety
510(k) K032951
§ 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).