(28 days)
Intended Use: The truFreeze System is intended for cryogenic destruction of tissue using Liquid Nitrogen spray that has a boiling point of -196ºC requiring either active or passive venting during surgical procedures.
Indications for Use: The truFreeze System is indicated for use as a cryosurgical tool in the fields of dermatology, gynecology, and general surgery, to ablate benign and malignant lesions.
The truFreeze system is a cryosurgical tool that applies medical-grade liquid nitrogen to the ablation area via a small, low pressure, open tipped catheter. The truFreeze System consists of a console and a disposable spray kit.
Console: The console is the central interface of the system and is comprised of a touch panel computer (TPC) and cryogen, suction, and electronics modules packaged in a mobile cart. Users interact with the console through a dual foot pedal and a touch panel. An off-the-shelf controller and associated software manage the cryogen level sensing, filling, pressure, cooling, defrost, suction, timing and data management functions. A fill kit, stored on the rear of the console, allows for liquid nitrogen transfer from the source tank to the console. Safety features include indicators, tank pressure relief valves, an isolated low voltage power system, and an emergency stop button to be used in the event of user or technical malfunction.
Disposable spray kit: There are 2 types of spray kits available. One kit is available for active venting procedures and one is available for passive venting procedures. Both active and passive venting kits are provided in a carton of five (5) individually packaged sterile, single-use catheters with introducers in individual pouches. Additionally, the active venting kit is provided with a carton of five (5) individually packaged sterile. single-use CDTs with associated tubing in individual pouches. Each carton within a spray kit contains the instructions for use. There is a proposed change to the active venting disposable spray kit. The proposed change reduces the Outside Diameter (OD) of the CDT from 20 French to 16 French without changing performance specifications, adds additional Marker Bands to the 16 French version of the CDT and makes the 16 Fr CDT and 20 Fr CDT available as a 5-pack box in addition to as a part of the active venting kit.
The provided text describes a 510(k) premarket notification for the truFreeze System, focusing on minor modifications to an already cleared device. Therefore, a full-scale clinical study with extensive acceptance criteria, ground truth establishment, and multi-reader comparative effectiveness studies as typically seen for novel diagnostic AI devices, is not applicable here.
Instead, the submission details a verification and validation process for specific physical changes to a component of the device (the Cryoablation Drug Delivery Tube, CDT). The "acceptance criteria" are essentially the performance specifications for these modified components.
Here's an analysis based on the provided text, structured to address your points where applicable, and noting when information is not present due to the nature of this submission:
Acceptance Criteria and Device Performance
The acceptance criteria are the "Test Specifications" and the "Reported Device Performance" is the "Result" column.
| Proposed Change | Acceptance Criteria (Test Specification) | Reported Device Performance (Result) |
|---|---|---|
| Reduce CDT OD | The CDT shall be less than or equal to 16.5 Fr | Pass |
| The CDT shall not crack, break or experience lumen separation after exposure to temperatures with the boundary range of - 196°C and 40°C. | Pass | |
| Shall have sufficient column strength to allow it to be advanced over a 0.072” Savary Wire | Pass | |
| Shall maintain structural integrity and not kink while looped in a minimum internal bend radius. | Pass | |
| A complete flex of the CDT shall meet current kinking specification. | Pass | |
| The bonded CDT connector will withstand a minimum of 10lbf pull force without failing. | Pass | |
| Flow Rate shall meet current specification. | Pass | |
| The CDT OD shall not deform per specification. | Pass | |
| The bonded CDT connector will shall meet current. pull force specification without failing. | Pass | |
| Enhance Visualization | Circumferential banding must be sufficient to identify the banding through an endoscope. | Pass |
| Shall be labeled with four side-by-side 0.100"±0.030" wide identifying bands 7.7" ±0.1" from the distal end. | Pass | |
| All 0.100" wide bands shall be 360 degrees. | Pass | |
| Reduce CDT OD (DV) | CDT diameter will be as small as possible while enabling gas egress and allowing it to pass through the majority of anatomies with and without dilation. | Pass |
| Enhance Visualization (DV) | CDT will have Mark Bands to assist user for performing the initial, approximate placement of the CDT. | Pass |
Note: (DV) indicates Design Validation Testing.
Study Details Addressing Your Points:
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- The document does not specify the sample sizes (e.g., number of CDTs tested) for the individual mechanical and material tests. These are typically internal verification tests.
- For the Design Validation tests:
- User Survey / Simulated Use (PRO-R-17-00193): The sample size for the user survey/simulated use is not explicitly stated. It would likely involve a small number of users.
- Animal Study (PRO-R-17-00198): The sample size (number of animals) for the animal study is not explicitly stated.
- Data provenance (country of origin, retrospective/prospective) is not mentioned, as these are internal design control activities for a physical device modification.
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)
- For the physical and functional tests, "ground truth" is established through engineering and material science standards and measurements. There are no "experts" in the sense of medical professionals establishing ground truth for diagnostic accuracy here.
- For the "User Survey / Simulated Use" and "Animal Study," the "experts" would be the participants in the survey/study and the veterinarians/surgeons conducting the animal procedures. Their number and specific qualifications are not detailed in this summary.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Adjudication methods like 2+1 or 3+1 are typically used for establishing ground truth in diagnostic accuracy studies where there's subjectivity (e.g., interpreting medical images). This is not applicable here as the tests are for physical and functional properties of a medical device component. The "pass" results imply that the device met the predefined specifications, which is a form of objective assessment.
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
- No, an MRMC comparative effectiveness study was not done. This type of study is relevant for evaluating the impact of an AI algorithm on human reader performance, typically in diagnostic imaging. The truFreeze System is a cryosurgical tool, and this submission concerns a minor physical modification to an existing component, not an AI diagnostic algorithm.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- No, a standalone algorithm performance study was not done. This device is a physical cryosurgical system and does not involve a standalone algorithm for diagnostic or prognostic purposes.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- The ground truth for the physical and functional tests is based on engineering specifications, material science properties, and direct objective measurements.
- For the "User Survey / Simulated Use," the ground truth would be the subjective feedback and observed performance from the users.
- For the "Animal Study," the ground truth would be the physiological outcomes and observations documented during and after the animal procedures.
- None of these involve pathology or long-term outcomes data related to disease diagnosis, as the device is a therapeutic (surgical) tool.
8. The sample size for the training set
- There is no training set in the context of this 510(k) submission. Training sets are used for machine learning algorithms. This submission is for a physical medical device.
9. How the ground truth for the training set was established
- Not applicable, as there is no training set.
§ 878.4350 Cryosurgical unit and accessories.
(a)
Identification —(1)Cryosurgical unit with a liquid nitrogen cooled cryoprobe and accessories. A cryosurgical unit with a liquid nitrogen cooled cryoprobe and accessories is a device intended to destroy tissue during surgical procedures by applying extreme cold.(2)
Cryosurgical unit with a nitrous oxide cooled cryoprobe and accessories. A cryosurgical unit with a nitrous oxide cooled cryoprobe and accessories is a device intended to destroy tissue during surgical procedures, including urological applications, by applying extreme cold.(3)
Cryosurgical unit with a carbon dioxide cooled cryoprobe or a carbon dioxide dry ice applicator and accessories. A cryosurgical unit with a carbon dioxide cooled cryoprobe or a carbon dioxide dry ice applicator and accessories is a device intended to destroy tissue during surgical procedures by applying extreme cold. The device is intended to treat disease conditions such as tumors, skin cancers, acne scars, or hemangiomas (benign tumors consisting of newly formed blood vessels) and various benign or malignant gynecological conditions affecting vulvar, vaginal, or cervical tissue. The device is not intended for urological applications.(b)
Classification. Class II.