The Thermoflex system is intended for the treatment of symptoms due to urinary outflow obstruction secondary to benign prostatic hyperplasia ("BPH"). It is indicated for use in men over the age of 50 years with prostate lengths between 2.0 cm and 6.4 cm who present symptoms of urinary outflow obstruction secondary to BPH.

Device Description

The Thermoflex system is a catheter based thermal therapy device for the treatment of symptoms due to urinary outflow obstruction secondary to BPH. The Thermoflex system combines a heating console/pump with a sterile, multiple balloon WIT prostatic catheter. Following insertion of the WIT prostatic catheter into the bladder through the urethra, a "locating" balloon is filled with a small volume of air and positioned within the bladder neck to insure proper placement of the treatment balloon within the prostate. A predetermined volume of water is added to the balloon dilation catheter ("treatment balloon"), causeing the treatment balloon to dilate within the prostate, creating pressure and insuring contact of the treatment balloon's surface with the prostatic tissue. Water is heated externally to the body and pumped through the thermally insulated catheter to the treatment site and back to the heating console/pump. At the treatment site, heat from the water is exposed to the urethra and prostatic tissue by means of physical contact of the treatment balloon with the target tissue. Heat from the water is transferred conductively to the tissue, inducing tissue ablation due to coagulation necrosis and tissue devitalization.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study information for the Argomed, Inc.'s Thermoflex system, based on the provided document:

Acceptance Criteria and Device Performance

The document does not explicitly state formal, quantitative acceptance criteria in a table format with pass/fail thresholds. Instead, it focuses on demonstrating substantial equivalence to predicate devices through a clinical study that assessed improvements in BPH symptoms and signs. The "acceptance" can be inferred from the reported clinical significance and safety.

Acceptance Criteria (Inferred from Clinical Objectives)	Reported Device Performance (Thermoflex System)
Improved urine flow rates	Clinically and statistically significant improvements
Reduced prostate volume	Clinically and statistically significant improvements
Reduced prostate symptomatology	Clinically and statistically significant improvements
Improved quality of life assessments	Clinically and statistically significant improvements
Acceptable safety profile	Adverse events observed are typical for devices used to treat BPH or for catheterization in general.

Study Details

Sample size used for the test set and the data provenance:
- Sample Size: Not explicitly stated as a numerical value for patients in the clinical study. It is described as a "multicenter, nonrandomized, prospective clinical study of a single patient group."
- Data Provenance: The document does not specify the country of origin. It indicates it was a "multicenter" study, which suggests multiple clinical sites, but location is not mentioned. The study was prospective.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document does not provide information on the number or qualifications of experts used to establish a "ground truth" for the test set. The study design centers on objective clinical endpoints (urine flow rates, prostate volume, symptom scores, quality of life assessments) rather than expert interpretation of images or data needing a "ground truth" consensus.
Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- The document does not describe an adjudication method for the test set. Given the nature of the clinical endpoints (quantitative measurements and patient-reported symptoms/QOL scores), a traditional adjudication process as seen in imaging or diagnostic studies is unlikely to have been employed.
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:
- No. This was a clinical study evaluating a medical device (Thermoflex system) for BPH treatment. It was not an MRMC study and did not involve AI assistance or human readers in the context of diagnostic interpretation. The comparison was to published safety and effectiveness information of predicate devices (TUNA and VLAP systems).
If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- No. The Thermoflex system is a physical medical device (catheter-based thermal therapy system), not a software algorithm. The study assessed the device's performance in treating BPH in human subjects.
The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The "ground truth" implicitly used for evaluating the device's effectiveness was based on clinical outcomes data and patient-reported assessments. These include objective measurements like urine flow rates and prostate volume, and subjective assessments of BPH symptoms and quality of life. The document states "changes in severity of BPH symptoms and signs from pretreatment to post-treatment."
The sample size for the training set:
- The document does not mention a training set. This is a clinical trial for a physical medical device, not a machine learning model, so the concept of a "training set" is not applicable in this context. The study described is the primary clinical evaluation.
How the ground truth for the training set was established:
- As there was no training set in the context of a machine learning model, this information is not applicable.

Summary

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AUG 26 1999

1991847 PG. I OF A

Argomed, Inc.'s Thermoflex system

Name of Device	Thermoflex™ Water-Induced Thermotherapy (WIT) System
Common or Usual Name	Thermal Therapy BPH Catheter System or WIT System
Classification Names	Electrosurgical Cutting and Coagulation Device (21 C.F.R. § 878.4400), Laser Surgical Instruments (21 C.F.R. § 878.4810), and Urethral Dilator (21 C.F.R. § 876.5520)
Product Codes	GEI, GEX, and KOE
Submitter	Argomed, Inc.3800 Gateway Centre BoulevardSuite 308Morrisville, North Carolina 27560
Phone:Facsimile:Contact Person:Date Prepared:	(919) 469-2340(919) 469-2779Richard B. KleinMay 28, 1999
Predicate Devices
Trade Name	Manufacturer	510(k)
Transurethral NeedleAblation ("TUNA") System	VidaMed, Inc.	K965199, K960918,and K951245
Optilase® Nd:YAGLaser ("VLAP") system	Trimedyne, Inc.	K954597
Prostatic BalloonDilation Catheter	Apex	K913477

Intended Use

The Thermoflex system, the VidaMed TUNA system, and the Trimedyne VLAP system have the same intended use: to provide thermal treatment to the prostate to treat symptoms due to urinary outflow obstruction secondary to BPH. The Thermoflex system and the Apex catheter are intended to treat symptoms due to urinary outflow obstruction secondary to BPH. The Thermoflex system and the predicate devices are indicated for use in men over the

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age of 50 years exhibiting the symptoms of urinary outflow obstruction. Both the Thermoflex system and the VidaMed TUNA system define limits on the length or size of the prostate prior to treatment to insure that thermal treatment is provided to the target tissue without exposure of non-target tissue. For the Thermoflex system, the minimum prostate length, to be determined by cystoscopic examination, is 2.0 cm, and the maximum length is 6.4 cm. For the VidaMed TUNA system, the prostate must be between 20 cc and 50 cc in size. Thus, the Thermoflex system has the same intended use and similar indications for use as these predicate devices.

Substantial Equivalence

The Thermoflex system, the VidaMed TUNA system, the Trimedyne VLAP system, and the Apex Prostatic Catheter have the same intended use: the treatment of symptoms due to urinary outflow obstruction secondary to BPH. The Thermoflex system and the predicate devices have similar principles of operation and technological characteristics. Each device is inserted into the urethra and serves to relieve pressure placed on the urethra by the prostate. Relief of the pressure reduces the symptoms of urinary outflow obstruction. As opposed to surgical procedures, such as transurethral resectioning of the prostate ("TURP"), the Thermoflex system and the TUNA and VLAP predicate devices displace and necrose prostatic tissue by the application of heat to the prostatic tissue. The Thermoffex system and the Apex Prostatic Catheter both relieve pressure of the prostate on the urethra by the application of pressure induced by dilation of the catheter.

The technological differences between the Thermoflex system and its predicate devices are the combination of heat transfer with dilation, the method of heat generation, the control of the generated heat, and the point of energy delivery within the prostate.

The Thermoflex system combines pressure from dilation of the catheter with the introduction of heat into the prostatic tissue to induce coagulation necrosis. The pressure from the Thermoflex system dilation ballows the uniform distribution of heat to the prostate providing the therapeutic necrotic effect. With the Thermoflex system, heat is generated externally to the body, and then circulated to the prostate through an insulated catheter that protects nontarget tissues, such as the rectum, the bladder, and the penile urethra. The VidaMed TUNA and the Trimedyne VLAP systems generate heat within the prostate by the conversion of RF energy or radiant light into heat. Heat is controlled in the Thermoflex system by the lack of energy generation within the prostate. The heated water cannot increase in temperature or impart additional energy into the prostate, as no energy source is present within the body. Both the Thermoflex system and the Trimedyne VLAP system apply the heat directly to the prostatic urethral lumen, inducing coagulation necrosis. The VidaMed TUNA

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system employs RF probes that are inserted through the urethral lumen into the prostate itself.

Performance Characteristics

The equivalence of the Thermoflex system to the predicate devices in the treatment of symptoms of urinary outflow obstruction secondary to BPH was assessed in a multicenter, nonrandomized, prospective clinical study of a single patient group. The objectives, study endpoints, and methods of analysis focused upon assessing changes in severity of BPH symptoms and signs from pretreatment to post-treatment, and in a comparison of these endpoints to published safety and effectiveness information available for the TUNA system and VLAP system predicate devices. The clinical evaluation demonstrated that the Thermoflex system for Water-Induced Thermotherapy treatment of BPH induced clinically and statistically significant improvements in urine flow rates, prostate volume, prostate symptomatology, and quality of life assessments. The adverse events observed using this device are typical for devices used to treat BPH or for catheterization in general. Thus, the WIT procedure using the Thermoflex system is a safe and effective treatment for BPH ..

Conclusion

The Thermoflex system has the same intended use and very similar principles of operation, technological characteristics, clinical efficacy, and clinical safety as a combination of several class II predicate devices, the VidaMed, Inc. Transurethral Needle Ablation ("TUNA") system (K965199, K960918, and K951245), the Trimedyne Optilase® Nd:YAG Laser ("VLAP") system (K954597), and the Apex Prostatic Balloon Dilatation Catheter (K913477). Thus, the

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...

Thermoflex system is substantially equivalent to legally marketed devices intended to treat symptoms due to urinary outflow obstruction secondary to BPH.

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Rockville MD 20850

Food and Drug Administration

9200 Corporate Boulevard

Image /page/4/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized eagle with three wing-like shapes, positioned to the right of a circular arrangement of text. The text reads "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" and is arranged around the upper portion of the circle.

AUG 26 1998

Mr. Richard B. Klein President & CEO ARGOMED, Inc. 3800 Gateway Centre Blvd. Suite 308 Morrisville, NC 27560

Re: K991847 Thermoflex™ Water-Induced Thermotherapy System Dated: May 28, 1999 Received: May 28, 1999 Regulatory Class: II 21 CFR §876.4300/Procode: 78 KNS 21 CFR §876.5520/Procode: 78 KOE 21 CFR §878.4810/Procode: 79 GEX

Dear Mr. Klein:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we 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). 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 (Premarket Approval), 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 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

This letter will allow you to begin marketing your device as described in your 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 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4613. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification"(21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers 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,

CAPT Daniel G. Schultz, M.D. Acting Director, Division of Reproductive, Abdominal, Ear, Nose and Throat. and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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510(k) Number (if known): _14991847

Device Name: Argomed, Inc. Thermoflex™ Water-Induced Thermotherapy System

Indications for Use:

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

(Division S . Off) Division o productive, Abdominal, ENT, and Radiolo al Devices 510(k) Number .

Prescription Use
(Per 21 CFR 801.109)

Over-The-Counter Use _ (Optional Format 1-2-96)

Regulation Number and Section

§ 876.4300 Endoscopic electrosurgical unit and accessories.

(a)
Identification. An endoscopic electrosurgical unit and accessories is a device used to perform electrosurgical procedures through an endoscope. This generic type of device includes the electrosurgical generator, patient plate, electric biopsy forceps, electrode, flexible snare, electrosurgical alarm system, electrosurgical power supply unit, electrical clamp, self-opening rigid snare, flexible suction coagulator electrode, patient return wristlet, contact jelly, adaptor to the cord for transurethral surgical instruments, the electric cord for transurethral surgical instruments, and the transurethral desiccator.(b)
Classification. Class II (performance standards).