(81 days)
The MICRO21 with Retic is a new MICRO21 intended use that follows the same process as the MICRO21 with WBC Diff, but instead locates, digitally stores and displays reticulated red blood cells (retics) to aid the technologist in performing the Reticulocyte Count procedure.
The MICRO21 with Retic is an automated microscopic system that locates reticulated red blood cells (retics), stores digital images of the cells and displays the images in an organized manner to aid technologists in performing the Reticulocyte Count procedure. The process involves preparing a blood wedge smear stained with a supravital stain, affixing a bar code to each slide, placing the slides into a frame holder and inserting the frame into the MICRO21. The instrument locates 1000 RBCs. The reticulated RBCs are stored as high magnification color images (1000x magnification). The images of retics stored by the instrument are displayed on a color monitor for review by a technologist. The technologist confirms that each reticulated RBC image displayed contains retic markings. If the image does not contain retic markings, the image is eliminated by the technologist and consequently not included in the retic count. A report of the percent of retics per 1000 RBCs is printed.
Here's a breakdown of the acceptance criteria and study details for the MICRO21™ with Retic, based on the provided text:
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Method Correlation | Mean correlation of .95 with manual method (NCCLS EP-9 standard for new methodology). | 0.95 mean correlation with the manual method. |
| RBC Location Sensitivity | High sensitivity for locating RBCs. | 99.7% sensitivity for locating RBCs (agreement with technologist). |
| Reticulated RBC Location Ability | Ability to accurately locate reticulated RBCs. | Confirmed through 99.7% sensitivity for general RBC location, and the successful correlation with the manual method which relies on reticulocyte identification. |
| Retic Count Aid | Aid technologists in performing the Reticulocyte Count procedure. | Confirmed by correlation with manual counts and the display functionality for technologists to review and confirm retics. |
2. Sample Size and Data Provenance
- Test Set Sample Size: 40 patient samples, from which 80 slides were created (two slides per sample).
- Data Provenance: The document does not explicitly state the country of origin. The study appears to be retrospective as it involves prepared slides from patient samples.
3. Number and Qualifications of Experts for Ground Truth
- Number of Experts: Two certified technologists.
- Qualifications of Experts: Certified technologists. The document does not specify their years of experience or precise certifications beyond "certified technologists."
4. Adjudication Method
- For Test Method One (correlation with manual method): Two technologists independently performed manual retic counts. The text does not explicitly state an adjudication method (like 2+1 or 3+1) if there were discrepancies between the two technologists' manual counts. It seems their individual manual counts were used for comparison.
- For Test Method Two (sensitivity): Two certified technologists independently observed the MICRO21's ability to locate RBCs and reticulated RBCs. The "agreement with the technologist" for sensitivity suggests their observations were the reference, but no specific adjudication process for disagreement is described.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC comparative effectiveness study was not explicitly described in the provided text. The study focused on correlating the device's output with manual methods performed by technologists and assessing the device's ability to locate cells, rather than measuring the improvement in human reader performance with augmentation versus without augmentation.
6. Standalone (Algorithm Only) Performance
- A standalone performance evaluation was implicitly conducted for some aspects. Test Method Two focused on the MICRO21's "ability to locate RBCs and reticulated RBCs" independently, with its sensitivity measured against technologists' observations. The device's fundamental function of identifying and storing images of retics before technologist review demonstrates an algorithmic component. However, the overall "process" described always includes technologist review (step 5 and 6), meaning the final "count" isn't purely standalone.
7. Type of Ground Truth Used
- Expert Consensus / Technologist Observation:
- For Test Method One (correlation): The ground truth for the reticulocyte count was established by manual retic counts performed independently by two technologists.
- For Test Method Two (sensitivity): The ground truth for RBC and reticulated RBC location was the agreement with the technologist's observation.
8. Sample Size for the Training Set
- The document does not provide information on the sample size used for the training set. Only the test set details are given.
9. How Ground Truth for the Training Set was Established
- The document does not provide information on how the ground truth for the training set was established, as it does not discuss the training process or data.
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Image /page/0/Picture/0 description: The image shows the date "MAY 17 1996" in bold, black font. The month is written in all capital letters, followed by the day and year. The numbers are clearly visible and easily readable. The date appears to be printed or stamped onto a document.
Image /page/0/Picture/1 description: The image shows the logo for Intelligent Medical Imaging, Inc. The logo features the letters "IMI" in a bold, sans-serif font. To the left of the letters is a graphic of interconnected dots, resembling a network or constellation. The words "Intelligent Medical Imaging, Inc." are printed in a smaller font below the letters.
510(K) SUMMARY
| Prepared by: | Christine B. Harper, MBA,MT(ASCP) |
|---|---|
| Title: | Senior Product Development Manager |
| Date: | February 7, 1996 |
| Trade Name: | MICRO21 ™ with Retic |
|---|---|
| Classification Name: | Automated Cell Locating Device |
| Classification Number: | 81JOY |
| Class: | II |
| Regulation Number: | 864.5260 |
The MICRO21™ with WBC Diff (White Blood Cell Differential) Ref. No. K925670/A is an automated microscopic system that locates WBCs, stores digital images of the cells and displays the images in an organized manner to aid technologists in performing the WBC Diff procedure. The MICRO21 process is substantially equivalent to the manual microscopic process.
Description:
The MICRO21 with Retic is a new MICRO21 intended use that follows the same process as the MICRO21 with WBC Diff, but instead locates, digitally stores and displays reticulated red blood cells (retics) to aid the technologist in performing the Reticulocyte Count procedure. A retic is defined as a nomnucleated Red Blood Cell (RBC) that contains two or more blue-stained particles or granulofilamentous material after staining with a supravital stain. A summary of the MICRO21 with Retic process is as follows:
- Prepare a blood wedge smear stained with a supravital stain. 1 .
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- Affix a bar code to each slide, place the slides into ; frame holder, and insert the frame into the MICRO21.
-
- The instrument locates 1000 RBCs.
- The reticulated RBCs are stored as high magnification color images (1000x magnification). 4.
- The images of retics stored by the instrument are displayed on a color monitor for review by a રું. technologist.
- The technologist confirms that each reticulated RBC image displayed contains retic markings. If 6. the image does not contain retic markings, the image is eliminated by the technologist and consequently not included in the retic count.
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- A report of the percent of retics per 1000 RBCs is printed.
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Image /page/1/Picture/0 description: The image shows the logo for Intelligent Medical Imaging, Inc. The logo features the letters "IMI" in a bold, stylized font. Above the letters is a graphic of interconnected dots, resembling a network or a constellation. The text "Intelligent Medical Imaging, Inc." is printed below the letters.
Test Methods:
Two testing methods were performed to validate the safety and effectiveness of the MICRO21 with Retic process. To conduct the tests, two slides were created from forty patient samples, (80 slides in total) including normal and abnormal values.
Test Method One employed the NCCLS EP-9 requirements for qualifying a new methodology versus the manual methodology being replaced. Using forty specimens with two slides from each specimen for a total of 80 slides, two technologists independently performed a munual retic count on each of the 80 sides. The same 80 slides were run on the MICRO21 with Retic with the two technologists reviewing the reticulated RBCs displayed by the MICRO21. The results of the 80 manual retic counts and the 80 MICRO21 retic counts were analyzed against the NCCLS EP-9 Mean Correlation Standard. The MICRO21 with Retic and the manual method showed a .95 mean correlation, which is within the NCCLS EP-9 requirements for a new methodology.
Test Method Two involved two certified technologists independently observing the MICRO21's ability to locate RBCs and reticulated RBCs on 39 slides. Over 39,000 RBCs were located by the MICRO21 with a sensitivity (agreement with the technologist) of 99.7%.
Conclusion:
The correlation determined by Test Method One, and the sensitivity determined by Test Method Two confirm the safety and effectiveness of the MICRO21 with Retic for the intended use of location, storage and display of reticulated RBC's to aid the technologist in performing the Retic Count procedure.
§ 864.5260 Automated cell-locating device.
(a)
Identification. An automated cell-locating device is a device used to locate blood cells on a peripheral blood smear, allowing the operator to identify and classify each cell according to type. (Peripheral blood is blood circulating in one of the body's extremities, such as the arm.)(b)
Classification. Class II (performance standards).