HEMAPROMPT GASTRIC by AERSCHER DIAGNOSTICS

HemaPrompt Gastric is a guaiac-based in-vitro method for the qualitative detection of occult blood in gastric aspirate or vomitus by medical professionals only. A separate segment of pH paper is provided on the slide for estimation of pH of the gastric juice.

It is used for the early detection of occult blood in such conditions as gastric trauma, gastric or duodenal ulceration, gastric cancer, esophageal varices, situations of exogenous or endogenous gastritis, leukemia, and hereditary telangiectasia. These conditions may be encountered in the emergency room, recovery room or intensive care.

Device Description

The HemaPrompt Gastric slide, used with a buffered developer and a buffered guaiac paper, is a guaiac based test for the detection of occult blood in gastric samples. The test is not affected by low pH, and is free from interferences by normal therapeutic concentrations of iron, ranitidine, and antacids. A separate area is provided to test for the pH of the specimen.

When a gastric specimen containing blood is applied to the HemaPrompt Gastric test paper, hemoglobin from the lysed blood cells in the sample comes in contact with the guaiac in the paper. The developer, a buffered solution of alcohol and hydrogen peroxide, which is applied with two drops to the guaiac on the slide, creates a peroxidase-like reaction in the presence of hemoglobin which in turn causes a blue coloration in the test paper. This test will turn blue in the presence of more than 100 mcg Hb/ ml gastric juice.

AI/ML Overview

The HemaPrompt Gastric device detects occult blood in gastric samples. The provided information details several studies to assess its performance.

1. Acceptance Criteria and Reported Device Performance:

The document implies an acceptance criterion for sensitivity at 100 mcg Hb/ml gastric juice.

Acceptance Criteria	Reported Device Performance	Study
Positive reaction at > 100 mcg Hb/ml gastric juice	100% positive reaction at 200 mcg Hb/ml or greater	Patient Gastric Samples, Intubated Volunteer Samples, PBS Samples
Positive reaction at > 100 mcg Hb/ml gastric juice	81.25% positive reaction at 100 mcg/ml (PBS samples)	PBS Samples
Not affected by low pH	Tested across pH 1.0 to 7.0 (via PBS samples)	PBS Samples
Not affected by normal therapeutic concentrations of iron, ranitidine, and antacids	Concentrations of ranitidine, ferrous sulfate, and an antacid (Mylanta) did not alter results	PBS Samples
Excellent reproducibility above 100 mcg/ml gastric juice	Excellent reproducibility demonstrated over a two-week period, with samples stored up to 10 days at 5%	Reproducibility study (not explicitly named or detailed)
Monitors react as expected	All monitors reacted in the expected manner (+ve turned blue and the "negative" monitor remained non-reactive)	Monitor reaction study (not explicitly named or detailed)

2. Sample Sizes and Data Provenance:

Test Set:
- Patient Gastric Samples: 12 samples (retrospective/clinical, origin not specified, but implies a clinical setting).
- Healthy Volunteer Gastric Samples: 8 samples obtained by intubation (prospective, volunteer, origin not specified).
- Synthetic Gastric Juice (PBS): Not explicitly stated how many distinct PBS samples were used, but they were subjected to titration for pH (1.0 to 7.0) and spiked with hemoglobin (50, 100, 200, 500 mcg/ml). This implies a controlled laboratory setting.

3. Number of Experts and Qualifications:

Not applicable. The assays are chemical reactions, and the results are read by observing a color change. The document does not mention any expert interpretation for establishing ground truth for the device's performance.

4. Adjudication Method:

Not applicable. The tests are based on chemical reactions resulting in a visual color change. There is no mention of human interpretation requiring adjudication.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:

No. This is a qualitative chemical test, not an imaging or diagnostic algorithm requiring human interpretation and a multi-reader study.

6. Standalone Performance:

Yes, the studies described are standalone performance evaluations of the HemaPrompt Gastric device. The document explicitly describes the device's reaction to various hemoglobin concentrations and conditions.

7. Type of Ground Truth Used:

The ground truth for the test set was established by:

Known Hemoglobin Concentrations: For the patient samples and healthy volunteer samples, known concentrations of hemoglobin were added to the samples. For the PBS samples, known concentrations of hemoglobin were titrated into the solutions. This represents a ground truth based on spiking with known analytes/concentrations.
Clinical observation: The initial positive results in intubated volunteer samples (37.5% with no added blood) imply that some intrinsic bleeding occurred due to the intubation procedure itself, which would be considered a clinical ground truth for the presence of blood, though not quantified.

8. Sample Size for Training Set:

Not applicable. This device is a chemical test, not a machine learning algorithm that requires a training set.

9. How Ground Truth for Training Set Was Established:

Not applicable, as there is no training set for this type of device.

Summary

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SEP 2 4 2003

510K SUMMAY OF HEMAPROMPT GASTRIC for use in detection of gastric occult blood. 【 OB CS COL requirements of SMDA 1990.

As with any occult blood test, results with HemaPrompt Gastric cannot be considered conclusive evidence of the presence or absence of upper bowel bleeding or pathology and is designed for use as a preliminary screening aid and is not intended to replace other diagnostic procedures such as endoscopy or Xray procedures. Furthermore the pH cannot be used to indicate the specimen is of gastric origin.

EXPECTED AND PERFORMANCE RESULTS

The use of guaiac impregnated paper for the detection of occult blood and its significance in gastric contents has been less extensively studied than fecal occult blood. One study of 153 gastric aspirates from 50 intubated healthy adults indicated all aspirates with more than 50 micrograms of hemoglobin! ml were positive with a buffered guaiac impregnated test paper. There was an apparent overall false positive rate of 25.5% in this study of normal intubated individuals, but even using less than 25 micrograms of hemoglobin / ml. as the test cut-off, 11.8% showed a positive reaction. The positive rate will be affected by the method of collection. A traumatic intubation can be expected to produce some degree of bleeding.

STUDIES HemaPrompt Gastric was studied with

12 patient gastric samples obtained by gastroscopy. a)
b) 8 healthy volunteer gastric samples obtained by intubation.
samples of a synthetic gastric juice of Phosphate Buffered Saline (PBS) each titrated with HCI to give pH's c) ranging from 1.0 to 7.0 and hemoglobin concentrations of 50, 100, 200 and 500 mcg/ml.

(a) It was found of the patient samples, none were positive initially, 37.5% (3/8) were positive with blood added to produce a concentration of 50 mcg / ml Hb, and 66% (8/12) were positive with 100 mcg / ml Hb and 100% of samples with blood added in concentrations of 200 mcg Hb / ml or greater reacted positively.

(b) Of the intubated volunteer samples, 37.5% (3/8) were positive with no added blood. 60% (3/5) were positive with 20 mcg/ml Hb added, 87.5% (718) were positive with 50 mcg/ml Hb added to the specimen, and 100% were positive at concentrations of 100 mcg / ml and greater of added hemoglobin. All samples with blood added in concentrations of 200 mcg Hb / ml or greater reacted positively, and all reacted in less than 60 seconds. The positive rate will be affected by the method of collection. A traumatic intubation can be expected to produce some degree of bleeding and an initial negative result under these circumstances assumes added weight compared to a positive result..

(c) Of the PBS samples, 50 mcg Hb/ ml produced a positive reaction 44% (7/16) of the time, with 100 mcg / ml 81.25% ( 13/16) of samples showed a positive reaction. At 200 mcg / ml and above fall samples showed a positive reaction. Furthermore, concentrations of ranitidine, ferrous sulfate, and an antacid (Mylanta) to be expected in the stomach after a maximum recommended dosing did not alter the HemaPrompt Gastric results. This does not necessarily apply in overdose situations when excessive iron compounds and certain H2 blockers e.g. cimetidine (Tagamet) could produce false positive reactions, and excess antacid or rantidine (Zantac) could produce a false negative.

The samples from each person were repeated over a two week period. Results demonstrated excellent HemaPrompt Gastric reproducibility at levels above 100 mcg/ ml gastric juice with all samples stored up to 10 days at 5% and showed excellent comparison to results obtained on the same samples with another commercially available test for this purpose

It was concluded that with gastric juice. HemaPrompt reacted reliably and definitely to hemoglobin levels above 100mcg / ml. gastric juice.

All monitors reacted in the expected manner (+ve turned blue and the "negative" monitor remained non-reactive). Exposing the guaiac paper to UV light for ten minutes inactivated the expected reaction.

SK3F

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SEP 2 4 2003

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

Robert Schreiber, M.D. Aerscher Diagnostics 353 High Street Chestertown, Maryland 21620

Re: K031356

Trade/Device Name: HemaPrompt Gastric Regulation Number: 21 CFR § 864.6550 Regulation Name: Reagent Occult Blood Regulatory Class: II Product Code: KHE Dated: July 29, 2003 Received: July 29,2003

Dear Dr. Schreiber:

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. Iisting 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). This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

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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,

Steven Putman

Steven I. Gutman, M.D., M.B.A. Director Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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Page 1 of 1

5 10(k) Number (if known):	K031356
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HemaPrompt Gastric Device Name: __

Indications For Use:

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use (Per 21 CFR 801.109) OR

Over-The---Counter Use

(Optional Format 1-2-.96)

T
Division Sign Off

Division Sign-Off

Office of In Vitro Diagnostic Device Evaluation and Safety

510(k) 031556 / s'

Regulation Number and Section

§ 864.6550 Occult blood test.

(a)
Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood is blood present in such small quantities that it can be detected only by chemical tests of suspected material, or by microscopic or spectroscopic examination.)(b)
Classification. Class II (special controls). A control intended for use with an occult blood test is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.