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The NEVA™ System is an device to measure and record penile erectile events nocturnally.
Measure and record penile erectile events nocturnally.

The UroMetrics NEVA system consists of three disposable electrodes sets, a portable battery powered recorder, a host interface, cables and a computer program. Two of the three electrode sets are placed on the penis so that one electrode set is on the glans terminating just proximal to the glans, one set is at the base of the penis terminating a fixed distance from the base of the penis. The third electrode is attached to the patient's hip. The wires from the electrodes terminate in a phone connector which plugs into the portable NEVA recorder.

The electrodes and the recorder are used by the patient to monitor nocturnal tumescence for up to three nights. The host interface and the computer program are used to prepare (initialize) the recorder for use and to download the data from the recorder for display and analysis on a physician's computer.

The NEVA system indicates penile tumescence by monitoring changes in volume, length and area. Due to a variety of factors (patient position, etc.) the size of the penis can change its shape. An increase in length, by itself, may not indicate tumescence. Tumescence is generally indicated by an increase in volume, length and area. This is the primary reason the NEVA system displays volume, length and area throughout the test.

Impedance values which are used to determine penile volume, length and area are continuously recorded at one second intervals. The one second time base and the change in volume data allow a physician to determine the fill rate once periods of tumescence are identified.

The NEVA system determines changes in volume by measuring the impedance within the penis. A low powered alternating current is sent from the electrode on the glans to the ground electrode on the hip. The remaining electrodes are used to measure the impedance. The electrode set at the base of the penis includes electrodes which are separated by a fixed distance. As the cross-sectional area of the blood volume in the penis increases, there is a decrease in measured impedance in the base electrode set. These impedance changes are then converted to a volume reading by the host computer. With an increase in distance between the base electrode and the electrode posterior to the glans (penis length) there is an increase in the impedance between these electrodes. This change in impedance is converted to a length reading.

To begin a test, the NEVA recorder is plugged into a computer through the host interface to a host computer running the NEVA software. The computer and software will recognize the recorder and will display a menu which allows the physician to download previously recorded data or initialize the recorder for a new test. To begin a new test, the physician enters the patient's name and other information and initializes the recorder. All previous data are cleared and the patient information is saved to the recorder.

The NEVA software allows the physician the option of real time measurements while connected to the computer. This capability is useful to demonstrate the proper placement of the electrodes and to check for proper operation. Once the NEVA recorder is initialized and the patient is instructed in its use, the recorder and electrodes are sent home with the patient. The electrodes are designed for single use so a separate set of electrodes is needed for each night (sleep period) of the test.

The NEVA recorder is normally in standby mode until the electrodes are placed on the patient and the connector is plugged into the recorder. When the connector is removed the recorder returns to the standby mode. Patients should be instructed to plug in the electrodes at the beginning of the test and unplug the electrodes at the end of the test. The recorder can store data for a maximum of 36 hours, typically three sleep periods.

At the end of the test period, the NEVA recorder is plugged into a computer through the host interface to a host computer running the NEVA software. The computer and software will recognize the recorder and will display a menu which allows the physician to download the data.

The data are then downloaded to the computer and stored on the computer's hard drive. The impedance data are converted to volume, length and crosssectional area plots which are displayed graphically on the computer screen.

The software incorporates a number of features which facilitate the analysis and interpretation of the data by the physician.

The provided text does not contain specific acceptance criteria or detailed results of a study that directly proves the device meets specific performance criteria in a quantifiable manner (e.g., sensitivity, specificity, accuracy).

Instead, it mentions:

• "Performance testing raised no issues, and the 510(k) included Comparative Testing and Function and Beta Testing." This is a general statement indicating that testing was performed and found acceptable for regulatory submission, but it doesn't provide the criteria or the results.
• The NEVA™ System is being cleared based on its substantial equivalence to the RigiScan® Plus System (K941781). The argument for substantial equivalence is that the differences in technical specifications, physical appearance, and design "do not affect the relative safety and effectiveness." This implies that the NEVA™ System is expected to perform comparably to the predicate device, but no quantitative performance metrics for either device are presented here.

Therefore, many of the requested details cannot be extracted from this document.

Here's an attempt to answer the questions based on the limited information available:

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

   Acceptance Criteria	Reported Device Performance
   Not explicitly stated (implied to be comparable safety and effectiveness to predicate device)	"Performance testing raised no issues."

"Differences... do not affect the relative safety and effectiveness of the NEVA™ System." |

2. Sample size used for the test set and the data provenance: Not mentioned.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not mentioned.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set: Not mentioned.

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: Not mentioned. This device is a measurement system, not an AI-assisted diagnostic tool for Human-in-the-loop performance improvement.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: The document implies standalone testing was done as it states "Performance testing raised no issues," and the system outputs data for physician analysis. However, no specific standalone performance metrics (e.g., accuracy of tumescence detection) are provided.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.): Not mentioned. For a penile tumescence monitor, ground truth would likely involve independent clinical assessment of erectile events or physiological measurements, but this is not specified.

8. The sample size for the training set: Not mentioned.

9. How the ground truth for the training set was established: Not mentioned.

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Measurement of penile cavernosal artery velocities. Not intended for fetal use.

Diagnostic ultrasound imaging or fluid flow analysis of the human body as follows: Peripheral Vascular (PWD)

The UroMetrics Knoll/MIDUS System is an office based Doppler ultrasound system designed to measure blood velocity in the penile cavernosal arteries. The system consists of a portable or desktop IBM compatible personal computer containing a proprietary circuit board and transducers. Blood velocity is determined by detecting the Doppler shifts of an 8 MHz ultrasound signal. Proprietary software converts this data into a useable waveform display, which is shown on the computer video display.

This a 510(k) premarket notification for the Knoll/MIDUS System, a bi-directional vascular Doppler with spectral analysis, which was submitted in 1997. As such, the document largely focuses on demonstrating substantial equivalence to a predicate device rather than presenting a detailed clinical study with acceptance criteria and a structured study to prove them, as would be expected for a more recent AI/ML-based device submission.

Therefore, much of the requested information regarding acceptance criteria, specific study design for proving those criteria, sample sizes, ground truth establishment for training and test sets, expert involvement, and MRMC studies is not explicitly available in this document.

Here's an analysis based on the provided text, highlighting what is present and what is absent:

Acceptance Criteria and Device Performance

The document does not explicitly state quantitative acceptance criteria for performance metrics of the device in the way one would see for an AI/ML device (e.g., minimum sensitivity, specificity, or F1-score). Instead, the "acceptance criteria" can be inferred to be related to demonstrating substantial equivalence to the predicate device in terms of:

1. Intended Use: Measurement of penile cavernosal artery velocities.
2. Technological Characteristics: Bi-directional vascular Doppler with spectral analysis, 8 MHz ultrasound signal.
3. Safety and Effectiveness: Implied by being substantially equivalent to a legally marketed device.

The document does not report specific device performance metrics (e.g., accuracy, precision) in a table format against predefined acceptance criteria for a study proving these. The entire submission acts as the "study" demonstrating substantial equivalence of the Knoll/MIDUS to the predicate device (SPECS USA, Inc. Stenodoc/EPC bi-directional vascular Doppler with spectral analysis, K946349).

Study Details (Based on available information)

Given the nature of a 1997 510(k) for a Doppler ultrasound system, the concept of "AI" and associated study methodologies (like those for AI/ML devices) are not applicable here. The device itself is a measurement tool, not an AI algorithm.

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

   • Acceptance Criteria: Not explicitly defined in quantitative performance terms. The overarching "acceptance criterion" for this submission is demonstrating substantial equivalence to the predicate device (SPECS USA, Inc. Stenodoc/EPC) regarding intended use, technological characteristics, and safety/effectiveness.
   • Reported Device Performance: No specific performance metrics (e.g., sensitivity, specificity, mean absolute error) are reported for the Knoll/MIDUS device directly against acceptance criteria. The performance is indirectly supported by its substantial equivalence to a predicate device that was already deemed safe and effective.

2. Sample sizes used for the test set and the data provenance: Not applicable. This submission does not describe a clinical performance study with a test set of patient data to measure device performance against. It's a submission for a hardware-based medical device.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. No test set requiring expert-established ground truth is described.

4. Adjudication method for the test set: Not applicable. No test set 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: Not applicable. This device is not an AI product, and no MRMC study is mentioned.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This device is not an algorithm, but a hardware system for measuring blood velocity, intended for human operation and interpretation.

7. The type of ground truth used: Not applicable in the context of an AI study. For a traditional medical device, "ground truth" might refer to established clinical methods or physical standards to validate measurements. The submission relies on the predicate device's established safety and effectiveness.

8. The sample size for the training set: Not applicable. There is no AI/ML model, so no training set.

9. How the ground truth for the training set was established: Not applicable.

Summary of Device and Regulatory Context for K971790:

• Device: Knoll/MIDUS, a bi-directional vascular Doppler with spectral analysis.
• Intended Use: Measurement of penile cavernosal artery velocities.
• Regulatory Pathway: 510(k) premarket notification, demonstrating substantial equivalence to a predicate device.
• Predicate Device: SPECS USA, Inc. Stenodoc/EPC bi-directional vascular Doppler with spectral analysis (K946349).
• Key Information Provided: Device description, intended use, classification, and a statement of substantial equivalence by the FDA.
• Missing Information (from an AI/ML perspective): No detailed performance study, no specific quantitative acceptance criteria for performance, no data on training/test sets, no expert involvement for ground truth, and no AI-specific evaluations (like MRMC or standalone algorithm performance).

The submission focuses entirely on the technical classification and equivalence to a previously cleared device, which was the standard regulatory approach for many medical devices in 1997.

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