Spectros T-Stat™ 303 Microvascular The Tissue Oximeter is intended for use as an adjunct monitor of the localized hemoglobin oxygen saturation of blood in the microvascular tissue spaces (StO2%) in infants, children, or adults at risk for reduced-flow and no-flow ischemic states.

The prospective clinical value of measurements made with the T-Stat™ Oximeter has not been demonstrated in disease states. The T-Stat™ Oximeter should not be used as the sole basis for diagnosis or therapy.

Device Description

The Spectros T-Stat™ 303 Tissue Oximeter is a broadband, multiwavelength, Visible Light Spectroscopy (VLS) monitoring system for measuring the saturation of hemoglobin with oxygen in the microvascular tissue spaces (StO2%).

The complete system consists of a disposable sensor probe connected to a software-driven electronic monitor. Data collection, analysis, and display functions are provided by the monitor. Illumination of the tissue is provided by a visible light source in the sensor probe placed near, on, or into the target tissue to be studied. Reflected light is captured and returned to the monitor via a detachable connection at the monitor end of the patient probe. StO2% is estimated using differential optical diffuse reflectance spectroscopy and fitting for background scattering over a range of reflected visible wavelengths.

AI/ML Overview

The provided text is a 510(k) summary for the Spectros T-Stat™ 303 Microvascular Tissue Oximeter. This submission is for modifications to an existing device (K040684, the predicate device), not a new device requiring a full clinical study to establish performance. Therefore, the document does not contain detailed information about acceptance criteria or a specific study proving the device meets those criteria in the way a de novo or PMA submission would.

Instead, the submission focuses on demonstrating that the modifications do not negatively impact safety or effectiveness and that the modified device remains substantially equivalent to the predicate. The "Test Summary" section describes re-verification and re-validation activities related to these specific modifications, rather than a comprehensive performance study against specific clinical acceptance criteria.

Below is an attempt to address your request based on the limited information available in the provided text, acknowledging that many fields will be "Not Applicable" or "Not Provided" due to the nature of this 510(k) submission.

Analysis of Acceptance Criteria and Device Performance for Spectros T-Stat™ 303 Microvascular Tissue Oximeter (K081233)

Summary: This 510(k) submission (K081233) concerns modifications to an already approved device (K040684). As such, the document primarily focuses on demonstrating substantial equivalence and the safety/effectiveness of the modifications, rather than presenting a de novo performance study against explicit clinical acceptance criteria for the entire device. The information provided outlines re-verification and re-validation steps for specific changes (housing, probes, software), indicating that the existing performance of the predicate device is assumed to be maintained for the core functionality.

1. Table of Acceptance Criteria and Reported Device Performance

Given that this 510(k) is for modifications, the "acceptance criteria" discussed are largely for the changes themselves to ensure they do not degrade existing performance, rather than new clinical performance goals. The document does not provide specific quantifiable performance metrics (e.g., accuracy, precision relative to a gold standard) for StO2% measurement as acceptance criteria for this submission.

Acceptance Criteria (for Modifications)	Reported Device Performance (for Modifications)
Compliance with IEC60601-1-2 (Monitor housing)	Re-verification of compliance with IEC60601-1-2 completed.
Shipping test per ISTA-1a (Monitor housing)	Shipping test per ISTA-1a completed.
Normal manufacturing final test and inspection (Probes)	The normal manufacturing final test and inspection was determined to be the only validation required for the endoscopic and oral probes.
Sterilization process re-validation (Smaller oral probe)	Sterilization process was revalidated with the new smaller oral probe.
Software updates re-validation (Software)	Software updates were revalidated using an in-house validation procedure.
Overall System Improvement/Equivalence	"The modified T-Stat 303™ Oximeter System represents an improvement over the predicate with better software performance, equivalent safety performance, and improved probe assortment that allows for better patient fit."

2. Sample Size Used for the Test Set and Data Provenance

The document does not describe a "test set" in the context of clinical performance data for the StO2% measurement. The "tests" mentioned relate to engineering and software validation of the modifications.

Sample Size for Test Set: Not applicable / Not provided. The tests mentioned (IEC compliance, shipping, sterilization, software validation) are typically engineering or bench tests, not clinical studies with patient sample sizes.
Data Provenance: Not applicable / Not provided. The testing described is internal re-verification and re-validation of modifications, not clinical data collection from patients.

3. Number of Experts and Qualifications for Ground Truth

The concept of "experts" establishing ground truth (e.g., radiologists for image interpretation) is not applicable to this type of submission. This 510(k) is for modifications to a physiological monitoring device and does not involve subjective interpretation or a diagnostic decision that would require expert consensus for ground truth.

4. Adjudication Method for the Test Set

Not applicable. There is no "test set" in the clinical sense, and therefore no adjudication method for ground truth.

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

No, an MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic devices where human readers interpret patient data (e.g., images). The T-Stat™ 303 Microvascular Tissue Oximeter is a physiological monitoring device that provides a quantitative StO2% measurement, not a device requiring human interpretation of complex clinical cases in the way an MRMC study evaluates.

6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study

The device is a monitor that provides a direct measurement (StO2%). Its performance is inherently "standalone" in that the algorithm generates the reading without human interpretation as an input to the measurement itself. However, the document does not describe a specific standalone performance study in the way one might for an AI/ML algorithm being validated against a ground truth. Rather, it generally refers to re-validation of software updates as part of the modifications. The performance of the core StO2% measurement algorithm would have been established in the predicate 510(k) (K040684).

7. Type of Ground Truth Used

For the modifications covered in this submission:

Monitor housing: Ground truth is defined by compliance standards (IEC60601-1-2 for safety, ISTA-1a for shipping).
Probes: Ground truth is established by manufacturers' final test and inspection standards, and re-validation of the sterilization process according to established protocols.
Software updates: Ground truth is established by an "in-house validation procedure," which would typically involve testing against functional requirements and possibly simulations or comparison to expected outputs.

For the core StO2% measurement functionality (established by the predicate device K040684): The document does not specify the ground truth used for the original device's performance validation. Typically for oximeters, this would involve in vivo studies comparing the device's readings to directly measured blood oxygen saturation (e.g., co-oximetry).

8. Sample Size for the Training Set

Not applicable / Not provided. The device is not an AI/ML device that requires a training set in the conventional sense. The "software updates" mentioned are likely bug fixes and user interface clarifications, not a re-training of a machine learning model.

9. How the Ground Truth for the Training Set Was Established

Not applicable / Not provided. As there is no described training set, there is no ground truth establishment for it.

Summary

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Kof1233

Section 7 - 510(k) Summary

l. Applicant Information

Spectros Corporation A. Applicant: 4379 Alpine Road, Suite 108 Portola Valley, CA 94028

B. Official Contact: Bill Curnan Director of Quality/Regulatory Spectros Corporation 4379 Alpine Road, Suite 108 Portola Valley, CA 94028

C. Date of Summary: 4/21/08

II. Device Information

T-Stat™ 303 Microvascular Tissue Oximeter A. Proprietary Name :
B. Common Name: Tissue Oximeter
C. Classification Name: Oximeter, Tissue (870.2700)
D. Product Code: MUD
E. Regulatory Class: ==============================================================================================================================================================================
F. Panel: Cardiovascular

III. Predicate Device

The device in this 510(k) represents a modification to the T-Stat 303™ Microvascular Tissue Oximeter approved in 510(k) K040684 which is the predicate device.

IV. General Description

Spectros T-Stat™ The 303 Tissue Oximeter is a broadband,

Spectros 510(k) Page 19 of 146

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multiwavelength, Visible Light Spectroscopy (VLS) monitoring system for measuring the saturation of hemoglobin with oxygen in the microvascular tissue spaces (StO2%).

V. Indications

The Spectros T-Stat™ 303 Microvascular Tissue Oximeter is intended for use as an adjunct monitor of the localized hemoglobin oxygen saturation of blood in the microvascular tissue spaces (StO2%) in infants, children, or adults at risk for reduced-flow and no-flow ischemic states.

VI. Comparison to Predicate

The system in this 510(k) represents a modification to the T-Stat303™ Oximeter System described in the predicate 510(k), K040684. These modifications consist of

1. Monitor housing changed from all metal to a molded housing with a metal front and back plate.
1. Addition of a shorter (.5M) Endoscopic Probe to the probe set for use in applications where the existing 2.3M length is excessive.
1. Addition of a smaller oral probe to the probe set to provide a better fit in smaller patients
1. Updated software which has eliminated some annovance bugs and clarified user interface.

VII. Test Summary

A. Monitor tests on the new housing consist of re-verification of compliance with IEC60601-1-2 and a shipping test per ISTA-1a.
B. The normal manufacturing final test and inspection was determined to be the only validation required.
C. Sterilization process was revalidated with the new smaller oral probe.
D. Software updates were revalidated using an in house validation procedure.

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VIII. Conclusions

Based upon the above test results the modified T-Stat 303™ Oximeter System represents an improvement over the predicate with better software performance, equivalent safety performance, and improved probe assortment that allows for better patient fit.

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Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. Inside the circle is a stylized symbol resembling an abstract human figure with outstretched arms.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

JUL 2 8 2008

Spectros Corporation c/o Mr. Bill Curnan Director of Quality/Regulatory 4370 Alpine Road, Suite 108 Portola Valley, CA 94028

Re: K081233

Trade/Device Name: T-Stat 303 Microvascular Tissue Oximeter Regulation Number: 21 CFR 870.2700 Regulation Name: Oximeter Regulatory Class: Class II (two) Product Code: MUD Dated: June 25, 2008 Received: June 27, 2008

Dear Mr. Curnan:

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 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 Part 801); good manufacturing practice requirements as set forth in the

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Page 2 - Mr. Bill Cuman

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. 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.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Center for Devices and Radiological Health's (CDRH's) Office of Compliance at (240) 276-0120. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding postmarket surveillance, please contact CDRH's Office of Surveillance and Biometric's (OSB's) Division of Postmarket Surveillance at 240-276-3474. For questions regarding the reporting of device adverse events (Medical Device Reporting (MDR)), please contact the Division of Surveillance Systems at 240-276-3464. 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 (240) 276-3150 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours.

Bram D. Zuckerr an. M.D. Director Division of Cardiovascular Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known): K O & / 2 3 3

Device Name: Spectros T-Stat™ 303 Microvascular Tissue Oximeter

Indications For Use:

Prescription Use (Part 21 CFR 801 Subpart D) AND/OR

Over-The-Counter Use (21 CFR 807 Subpart C)

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

gmoo

vision of Cardiovascular Devices

510(k) Number

Page 1 of 1

Spectros 510(k) Page 18 of 146

Regulation Number and Section

§ 870.2700 Oximeter.

(a)
Identification. An oximeter is a device used to transmit radiation at a known wavelength(s) through blood and to measure the blood oxygen saturation based on the amount of reflected or scattered radiation. It may be used alone or in conjunction with a fiberoptic oximeter catheter.(b)
Classification. Class II (performance standards).