(44 days)
The Nvision VLE Imaging System is indicated for use as an imaging tool in the evaluation of human tissue microstructure, including esophageal tissue microstructure, by providing two-dimensional, cross-sectional, real-time depth visualization.
The NinePoint Medical NvisionVLE™ Imaging System is a general imaging system comprised of the NvisionVLETM Console, NvisionVLETM Optical Probe and the NvisionVLE™ Inflation Accessory Kit. The NvisionVLE™ Optical Probe is made up of an optical probe subassembly and a quide sheath. The optical probe subassembly is a fiber optic probe assembly secured inside a flexible, stainless steel torque shaft. The distal optics are housed in a stainless steel hypotube which is attached to the torque shaft. The proximal end of the optical fiber and torque shaft terminate in a standard fiber optic connector and catheter connector which interfaces with the system console. The optical probe subassembly transmits the optical signal and detects the reflected optical signal for image reconstruction of the targeted tissue. The guide sheath is a coaxially-designed balloon sheath. The sheath is composed of a PET balloon and a nylon shaft. The inner lumen of the sheath is sealed, enclosing the optical probe subassembly. The guide sheath is positioned within the organ structure of interest and allows the probe to rotate in a helical pattern while positioned in the inner lumen allowing for image reconstruction of the targeted tissue.
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance (Proposed Enhancements) |
|---|---|
| Durability / Resistance to Failure in Tortuous Anatomy | 100% of enhanced probe samples passed the most tortuous curve (Tortuous Curve 4). All 13 enhanced samples passed all four tortuous curves. |
| No binding of the torque coil leading to optical fiber fracture | No failures (binding of torque coil, fracture of optical fiber, failure to transmit signal) observed in enhanced samples across tortuous curves. |
| Improved device trackability | Stated as a benefit of the torsionally-stiffer torque coil, though not explicitly an acceptance criterion or quantified in the performance data. |
| Reduced optical signal disruption and incomplete imaging in tortuous anatomy | Stated as a benefit of the torsionally-stiffer torque coil, though not explicitly an acceptance criterion or quantified in the performance data. |
| Better absorption of vibrational and friction forces in tortuous anatomies | Supported by the pass rates in tortuous curves, indicating improved resilience. |
| Reduced stress on the optical fiber | Supported by the pass rates, as failure involves optical fiber fracture due to stress. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size:
- Initial Engineering Test Samples: 5 K120800 Controls, 5 Proposed Enhancements (Total = 10 samples)
- Manufacturing Build Samples: 10 K120800 Controls, 7 Proposed Enhancements (Total = 17 samples)
- Overall Reported (summary): 15 control samples, 13 enhanced samples (This slightly differs from the sum of the detailed tables (15 controls vs 17 controls; 13 enhanced vs 12 enhanced). The summary likely refers to the effective number of control samples that experienced failure across the two tables combined, and the number of enhanced samples that successfully completed the most rigorous testing.)
- Data Provenance: The data appears to be retrospective in the sense that it evaluates modifications to an already cleared device and compares them against the previously cleared device. It's an internal engineering and manufacturing evaluation. The country of origin is not explicitly stated, but the company is based in Cambridge, Massachusetts, USA, suggesting the testing was likely conducted in the US.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. This study is a performance test on device durability and mechanical integrity, not an evaluation of diagnostic accuracy requiring expert interpretation of images or patient outcomes. The "ground truth" for this test is the physical failure of the device (binding, fiber fracture, signal loss) under simulated tortuosity.
4. Adjudication Method for the Test Set
Not applicable. The outcome (pass/fail) is objectively determined by whether the device's optical fiber fractured or the torque coil bound, leading to a loss of signal. This is a direct physical outcome rather than an interpretation requiring adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. This study assesses the physical durability and mechanical performance of the device's components (optical probe and guide sheath), not its effectiveness in diagnostic tasks with human readers.
6. Standalone Performance Study (Algorithm Only)
Yes, in a sense. This is a standalone device performance study focusing on the mechanical durability of the device itself, rather than an algorithm. The "algorithm" aspect of imaging systems (image reconstruction, etc.) is not evaluated here, only the physical integrity of the probe.
7. Type of Ground Truth Used
The ground truth used is physical device failure (failure of the torque coil to bind, fracture of the optical fiber, and subsequent failure to transmit signal) under defined simulated conditions of tortuosity.
8. Sample Size for the Training Set
Not applicable. This study does not involve a "training set" in the context of machine learning. It's a physical engineering and manufacturing test of device durability.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for an algorithm. The "ground truth" for the test set (physical failure) was established by observing the operational state of the device under stress in a test fixture.
§ 892.1560 Ultrasonic pulsed echo imaging system.
(a)
Identification. An ultrasonic pulsed echo imaging system is a device intended to project a pulsed sound beam into body tissue to determine the depth or location of the tissue interfaces and to measure the duration of an acoustic pulse from the transmitter to the tissue interface and back to the receiver. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II (special controls). A biopsy needle guide kit intended for use with an ultrasonic pulsed echo imaging system only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.