FLOW NOW is indicated for monitoring blood flow in peripheral vessels during and following reconstructive microvascular procedures, re-implantation, and free flap transfers. Postoperatively, blood flow can be detected on an as needed basis for up to 7 days. The FLOW NOW Doppler probe is not intended to be a permanent implant and should be removed 3 to 14 days postoperatively.

Device Description

The GEM FLOW NOW (FLOW NOW) device is comprised of an implantable non-active silicone vessel sleeve (Figure 2), a 20 MHz ultrasonic Doppler transducer (probe) and probe wire, suture sleeve, probe connector, and an external lead that connects to a monitor. FLOW NOW has a soft, pliable silicone "vessel sleeve" that retains the Doppler probe via press-fit into a silicone bore. The device comes with vessel sleeve and probe already assembled.

The FLOW NOW Device is intended for monitoring blood flow in vessels. It is indicated for monitoring blood flow in peripheral vessels intraoperatively, and following reconstructive micro-vascular procedures, re-implantation, and free-flap transfers. Post-operatively, blood flow can be detected on an as needed basis for up to 7 days. The FLOW NOW Doppler probe is not intended to be a permanent implant and should be removed 3 to 14 days post-operatively. The FLOW NOW device is intended for use with both currently cleared FLOW COUPLER Monitors (GEM1020M and GEM1020M-2).

The probe is removed from the patient 3 to 14 days after implantation, once monitoring is complete. The probe is separated from the vessel sleeve and removed from the patient's body. non-invasively, by the surgeon pulling on the probe wire outside the patient's body. The silicone vessel sleeve remains permanently implanted. The FLOW NOW device can be used to monitor blood flow through veins and arteries ranging from 2.0 to 4.0 mm in outside diameter.

AI/ML Overview

The provided text is a 510(k) Summary for the GEM FLOW NOW (GEM2770-FN) device. It details the device's technical characteristics and claims of substantial equivalence to a predicate device but does not contain information about the acceptance criteria or a study proving device performance against those criteria in the context of human reader improvement with AI assistance (MRMC study) or standalone algorithm performance.

The document primarily focuses on non-clinical bench testing to demonstrate that the GEM FLOW NOW met defined specifications and comparable performance to its predicate device. It explicitly states that "Clinical performance testing was not required for the GEM FLOW NOW device."

Therefore, I cannot provide the requested information regarding acceptance criteria, reported device performance in those specific contexts, sample sizes for test sets, data provenance, expert details, adjudication methods, MRMC study effect sizes, or standalone algorithm performance.

Here's what I can extract based on the provided text, focusing on the available performance data:

1. A table of acceptance criteria and the reported device performance

The document mentions that "Pre-determined performance specifications were tested, and verification and validation activities were conducted to demonstrate that the GEM FLOW NOW met the defined criteria." However, the specific quantitative acceptance criteria and the detailed reported device performance are not provided in this document. It only states a general conclusion: "The GEM FLOW NOW met acceptance criteria and demonstrated comparable performance to the predicate device for the equivalent indications for use."

2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

This information is not provided as the performance data described is non-clinical bench testing, not a clinical study with a test set of patient data.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

This information is not applicable/provided. The document discusses non-clinical bench testing, not studies requiring expert review of patient data for ground truth establishment.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

This information is not applicable/provided. No clinical test set requiring adjudication is described.

5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

A multi-reader multi-case (MRMC) comparative effectiveness study was not done. The document explicitly states: "Clinical performance testing was not required for the GEM FLOW NOW device." This means no study involving human readers or AI assistance was conducted or reported here.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

A standalone algorithm performance study was not done. The device is a physical diagnostic tool (ultrasonic pulsed doppler imaging system) and not an AI algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

For the non-clinical bench testing, the ground truth would be based on engineering specifications and measurements from the physical device. Specific details are not provided.

8. The sample size for the training set

This information is not applicable/provided. The device is not an AI/ML algorithm that requires a training set.

9. How the ground truth for the training set was established

This information is not applicable/provided. The device is not an AI/ML algorithm that requires a training set.

Summary

{0}------------------------------------------------

Image /page/0/Picture/0 description: The image shows the logo for the U.S. Food & Drug Administration (FDA). The logo consists of two parts: the Department of Health & Human Services logo on the left and the FDA logo on the right. The FDA logo features the letters "FDA" in a blue square, followed by the words "U.S. FOOD & DRUG" in blue, and "ADMINISTRATION" in a smaller font size below.

January 28, 2024

Synovis Micro Companies Alliance Julie Carlston Senior Manager, Regulatory Affairs (A subsidiary of Baxter International Inc.) 439 Industrial Lane Birmingham, Alabama 35211

Re: K233394

Trade/Device Name: GEM FLOW NOW (GEM2770-FN) Regulation Number: 21 CFR 892.1550 Regulation Name: Ultrasonic pulsed doppler imaging system Regulatory Class: Class II Product Code: IYN, ITX Dated: October 3, 2023 Received: October 3, 2023

Dear Julie Carlston:

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 (the 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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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.

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

{1}------------------------------------------------

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review. the OS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Stephen C. Browning -S

LCDR Stephen Browning Assistant Director Division of Cardiac Electrophysiology, Diagnostics and Monitoring Devices Office of Cardiovascular Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

{2}------------------------------------------------

DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration

Indications for Use

510(k) Number (if known) K233394

Device Name GEM FLOW NOW (GEM2770-FN)

Indications for Use (Describe)

Type of Use (Select one or both, as applicable)
Prescription Use (Part 21 CFR 801 Subpart D)	Over-The-Counter Use (21 CFR 801 Subpart C)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

This section applies only to requirements of the Paperwork Reduction Act of 1995.

DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

{3}------------------------------------------------

Image /page/3/Picture/0 description: The image shows the logo for GEM, which stands for Global Excellence in Microsurgery. The logo is in orange and the text "K23339" is above the logo. The logo is a stylized "GEM" with the words "Global Excellence in Microsurgery" below it.

Image /page/3/Picture/1 description: The image contains the word "Baxter" in a stylized, bold, blue font. The font appears to be italicized, with the letters slightly slanted to the right. The word is prominently displayed and takes up a significant portion of the image.

510(k) Summary

I. Submitter's Information

Company Name: Synovis Micro Companies Alliance (A subsidiary of Baxter International Inc.) Address: 439 Industrial Lane, Birmingham Alabama, 35211, USA Establishment Registration Number: 1062741

Contact Person:	Julie Carlston
Phone Number:	+1 (571) 299-9806
Fax Number:	+1 (651) 642-9018
Email Address:	julie_carlston@baxter.com

Date Prepared: October 3, 2023

II. Device Information

Trade Name:	GEM FLOW NOW (GEM2770-FN)
Common Name:	Ultrasonic pulsed doppler imaging system
Classification Name:	System, Imaging, pulsed Doppler, Ultrasonic
Regulatory Class:	Class 2
Regulation:	892.1550
Product Code:	IYN, ITX

Predicate Device III.

GEM Flow Coupler Device and System K143589 (Reference device: Cook-Swartz Doppler Probe K171272)

Device Description IV.

{4}------------------------------------------------

Image /page/4/Picture/0 description: The image shows the logo for GEM, which stands for Global Excellence in Microsurgery. The logo is in orange and teal colors. The text "K233394" is located at the top left corner of the image.

Image /page/4/Picture/1 description: The image shows the word "Baxter" in a bold, sans-serif font. The word is written in a bright blue color. The letters are slightly slanted to the right, giving the word a dynamic appearance. The background is plain white.

is not intended to be a permanent implant and should be removed 3 to 14 days post-operatively. The FLOW NOW device is intended for use with both currently cleared FLOW COUPLER Monitors (GEM1020M and GEM1020M-2).

V. Indications for Use

VI. Intended Use

FLOW NOW is intended for monitoring blood flow in vessels.

VII. Technological Characteristics

The technological specification of the GEM FLOW NOW and its predicate device have been evaluated to determine equivalence. As detailed in the Substantial Equivalence section of this 510(k) submission, upon reviewing and comparing intended use, design, principle of operation and overall technology characteristics, GEM FLOW NOW is determined by Synovis Micro Companies Alliance to be substantially equivalent to existing legally marketed devices (Table 1).

	Subject Device	Predicate Device	Determination
Product Name	GEM FLOW NOW	GEM FLOW COUPLERSystem	NA
510(k) Holder	Synovis MicroCompanies Alliance, Inc,a subsidiary Of BaxterInternational Inc.	Synovis Micro CompaniesAlliance, Inc, a subsidiaryOf Baxter InternationalInc.	NA
510(k) Number	TBD	K143589	NA
Product Code	IYN, ITX	MVR, DPW	Equivalent
Regulation	892.1550	878.4300	Equivalent
Classification	Class II	Class II	Same
	Subject Device	Predicate Device	Determination
Intended Use	FLOW NOW is intendedfor monitoring bloodflow in vessels.	The FLOW COUPLERDevice and System isintended to be used in theanastomosis of veins andarteries normallyencountered inmicrovascular and vascularreconstructive proceduresand in the detection ofblood flow andconfirmation of vesselpatency following end-to-end anastomosis ofvessels.	Equivalent
Indications for Use	FLOW NOW isindicated for monitoringblood flow in peripheralvessels during andfollowing reconstructivemicrovascularprocedures, re-implantation, and freeflap transfers.Postoperatively, bloodflow can be detected onan as needed basis for upto 7 days. The FLOWNOW Doppler probe isnot intended to be apermanent implant andshould be removed 3 to14 days postoperatively.	The FLOW COUPLERDevice is a single use,implantable device that isintended to be used in theend-to-end anastomosis ofveins and arteries normallyencountered inmicrosurgical and vascularreconstructive procedures.The FLOW COUPLERDevice includes a pair ofpermanently implantedrings which secure theanastomosis and aremovable Doppler probethat is press-fit onto one ofthe rings. When the FLOWCOUPLER Device is usedin conjunction with theFLOW COUPLERMonitor, the FLOWCOUPLER System isintended to detect bloodflow and confirm vesselpatency intraoperativelyand post-operatively at theanastomotic site. Post-operatively, blood flowcan be detected on an asneeded basis for up to 7days. The FLOWCOUPLER Doppler probeis not intended to be apermanent implant andshould be removed 3 to 14days post-operatively.	Equivalent.
How Supplied	Sterile, single use	Sterile, single use	Same
Principle of operation	Silicone vessel sleeve issecured around the targetvessel with a vascularclip, with the probe inliquid contact with the	FLOW COUPLER Deviceimplantable rings are usedto perform end-to-endanastomosis of bloodvessels. The removable	Equivalent
	Subject Device	Predicate Device	Determination
	The Doppler probe isconnected to the FLOWCOUPLER Monitor viathe external lead, whichallows it to transmit aDoppler signal caused byblood flow. The probewire is secured at theskin entry site using thesuture sleeve. Oncefunction is confirmed,the surgical site is closedusing standardtechniques, with thevessel sleeve andDoppler probeimplanted. The Dopplerprobe remains in placefor 3-14 days, at whichpoint it is removed. Thesilicone vessel sleeve ispermanently implanted.	attached onto one of therings and the probe lead isconnected to the FLOWCOUPLER Monitor,which detects blood flow.Once function isconfirmed, the surgical siteis closed using standardtechniques, while the ringsand Doppler probe remainin place, and the probelead is secured at the skinentry site. The dopplerprobe remains in place for3-14 days, at which point itis removed. The ringspermanently implanted.
Compatible Monitor	GEM FLOW COUPLERMonitor	GEM FLOW COUPLERMonitor	Same
Time fromimplantation to proberemoval	3-14 days	3-14 days	Same
Monitoring Duration	7 days	7 days	Same
Vessel size	2-4mm OD	2-4 mm OD	Same
Biocompatibility	Per ISO 10993	Per ISO 10993	Same
Sterilization	10-6 SAL (EtO)	10-6 SAL (EtO)	Same

Table 1: Overview of Substantial Equivalence

{5}------------------------------------------------

Image /page/5/Picture/0 description: The image contains the text "K233394" at the top, followed by the word "GEM" in a large, orange, sans-serif font. Below "GEM" is the text "Global Excellence in Microsurgery" in a smaller, sans-serif font. The word "GEM" is stylized with the letters connected.

Image /page/5/Picture/1 description: The image shows the word "Baxter" in a bold, sans-serif font. The word is written in a bright blue color. The letters are slightly slanted to the right, giving the word a dynamic appearance. The background is plain white, which makes the blue letters stand out.

{6}------------------------------------------------

Image /page/6/Picture/0 description: The image shows the logo for GEM, which stands for Global Excellence in Microsurgery. The logo is orange and teal. The text "K233394" is located in the upper left corner of the image.

Image /page/6/Picture/1 description: The image shows the word "Baxter" in a bold, blue font. The font is sans-serif and the letters are slightly slanted to the right. The word is centered and takes up most of the image.

VIII. Performance Data

Non-Clinical

Bench performance testing was performed after applicable aging, distribution, environmental and/or implantation conditioning to evaluate and compare the technological and performance characteristics. Pre-determined performance specifications were tested, and verification and validation activities were conducted to demonstrate that the GEM FLOW NOW met the defined criteria.

Performance evaluation of the GEM FLOW NOW during the design validation and verification was completed by applying methods of internationally recognized standards such as, EN ISO 10993-1:2018 Biological evaluation of medical devices – Part 1: Evaluation and Testing within a risk management process, EN ISO 11737-2:2009, Sterilization of Medical Devices -Microbiological Methods - Part 2: Tests of sterility performed in the definition, validation and maintenance of a sterilization process, EN IEC 62366: 2015, Medical devices – Application of usability engineering to medical device, among others.

{7}------------------------------------------------

Image /page/7/Picture/0 description: The image shows the text "K233394" in the upper left corner. Below the text is the GEM logo in orange. The logo also includes the text "Global Excellence in Microsurgery" in a smaller font.

Image /page/7/Picture/1 description: The image shows the word "Baxter" in a bold, sans-serif font. The word is in blue color. The letters are slightly slanted to the right, giving the word a dynamic appearance. The background is plain white.

The GEM FLOW NOW met acceptance criteria and demonstrated comparable performance to the predicate device for the equivalent indications for use.

Clinical

Clinical performance testing was not required for the GEM FLOW NOW device.

IX. Conclusion

The device is substantially equivalent to the predicate device with respect to indications for use, and technological characteristics and does not raise new questions of safety and effectiveness.

Regulation Number and Section

§ 892.1550 Ultrasonic pulsed doppler imaging system.

(a)
Identification. An ultrasonic pulsed doppler imaging system is a device that combines the features of continuous wave doppler-effect technology with pulsed-echo effect technology and is intended to determine stationary body tissue characteristics, such as depth or location of tissue interfaces or dynamic tissue characteristics such as velocity of blood or tissue motion. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.