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Presygen™/si-1 is indicated for use in hospital facilities, along with clinical assessment of signs and symptoms, by healthcare professionals for non-invasive and non-diagnostic measure of relative temporal variation in oxygen saturation (StO2) in superficial tissue. Presygen™/si-1 displays two-dimensional color-coded images of tissue oxygenation of the scanned surface and reports tissue oxygenation measurements in selected tissue regions. Presygen™/si-1 is intended for adults only (22 and over).

Presygen™/si-1 is a standalone, non-contact tissue oxygen saturation oximeter based on multispectral optical imaging techniques. The mode of action is to transmit lights at four (4) known wavelengths through blood in superficial tissue and measure the tissue oxygen saturation (StO2), based on the amount of diffusely reflected light.

The Presygen™/si-1 software provides user control of the device and access to stored data, through a Graphical User Interface (GUI). The software controls hardware elements of the device such as illuminators, sensors, display and Input/Output, and manages communication between these elements and between processors and memory. The software also performs calculations to derive Tissue Oxygen Saturation (StO2) from optical inputs and display this to the device user in a two-dimension (2D) spatial map.

The Presygen™/si-1 device has been designed with the additional capability of compensating for melanin levels in the skin, since absorption of light by melanin affects the measurement of the oxygenated hemoglobin and deoxygenated hemoglobin through the skin.

The device consists of the following:

• Imaging head: Contains optics, lasers, and electronics to display the %StO2 .
• . Base compartment: Includes the wheels, brakes mechanism, SMB (Smart Multi-Media Board), power switch, certified power supply, fans, filters and cabling
• . Touchscreen monitor display: User interface, display of image, and patient data
• Keyboard: Used to enter user or patient information into the device .
• Accessory: The Presygen™/si-1 Sterilized Drape is a prepackaged single-use third party . drape that is used with Presygen™/si-1 to avoid contamination during the imaging process.

The provided text is a 510(k) summary for the Presygen™/si-1 device, an Oximeter. It details the steps taken to demonstrate the device's substantial equivalence to a predicate device (Kent Camera, K113507) and a reference device (T.Ox™, K042657).

1. Acceptance Criteria and Reported Device Performance

The general acceptance criteria for this device seem to be based on demonstrating substantial equivalence to predicate and reference devices, particularly in the measurement of tissue oxygen saturation (StO2) and its temporal variation. Performance is evaluated through phantom studies and clinical studies, focusing on accuracy, uniformity, and consistency with existing devices, especially across different Fitzpatrick Skin Types.

While direct numerical acceptance criteria for various metrics are not explicitly laid out in a table format in the provided text, the results of the studies serve as the reported device performance, indicating whether these (often implicit) criteria were met.

Here's an attempt to structure the information based on the reported results, interpreting the criteria from the outcomes:

2. Sample Sizes and Data Provenance

• Clinical Study 1:
  • Sample Size: 55 subjects (199 data points). 52 subjects included in data analysis, 3 excluded due to incomplete data.
  • Data Provenance: Prospective, unblinded, convenience sample population volunteers from the general community. No specific country of origin is mentioned, but typically for FDA submissions, studies conducted in the US are preferred, or international studies must meet FDA standards. Given the context of a US FDA submission, it's highly likely to be US-based or globally recognized clinical research. Retrospective/Prospective: Prospective.
• Clinical Study 2:
  • Sample Size: 20 subjects (6 male, 14 female).
  • Data Provenance: Prospective, unblinded, convenience sample population who self-reported as being healthy. Laboratory setting. Retrospective/Prospective: Prospective.
• Phantom Study for Bench Validation:
  • Sample Size: 3 phantom sets.
  • Data Provenance: Bench study, independent validation.

3. Number of Experts and Qualifications for Ground Truth

The document does not mention the use of experts to establish a "ground truth" in the traditional sense for the clinical studies. Instead, the ground truth for performance comparison is established by comparing the device's measurements (StO2) against measurements from a legally marketed predicate device (Kent Camera) and a reference device (T.Ox™ Tissue Oximeter). The evaluation is based on statistical equivalence of these measurements rather than expert consensus on images or findings.

For the phantom study, the "ground truth" was established by spectrophotometer measurements of the controlled phantom samples, which were fabricated with known, targeted StO2 values. This is an objective, technical ground truth rather than human expert opinion.

4. Adjudication Method for the Test Set

No adjudication method is described. As the studies compare quantitative measurements of StO2 from different devices rather than subjective interpretations or classifications that would require expert review and adjudication (e.g., in an imaging study), an adjudication method is generally not applicable or described in this context.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, an MRMC comparative effectiveness study was not conducted. This type of study is typically performed for diagnostic imaging devices where human readers interpret medical images, and the AI's assistance to these readers is being evaluated. The Presygen™/si-1 is an oximeter measuring tissue oxygen saturation, not an imaging device requiring human interpretation in the sense that would necessitate an MRMC study. The studies focused on the device's measurement equivalence to existing oximetry devices.

6. Standalone (Algorithm Only) Performance

Yes, a standalone performance evaluation was done. The entire study focuses on the Presygen™/si-1 device itself, which includes the software's ability to calculate and display StO2 from optical inputs. The phantom study, in particular, assesses the standalone measurement accuracy and spatial uniformity of the device. The clinical studies compare its direct output to other devices, without integrating a human "reader" into the core function of StO2 measurement generation. The device is intended for use by healthcare professionals as a tool, but its fundamental output (StO2 values) is algorithm-generated.

7. Type of Ground Truth Used

• Phantom Study: The ground truth was objective, calibrated measurements from a spectrophotometer of phantoms specifically designed to have known, targeted StO2 values.
• Clinical Studies: The "ground truth" was effectively the measurements from the predicate device (Kent Camera) and a reference device (T.Ox™ Tissue Oximeter). The goal was to prove substantial equivalence, meaning the new device's measurements were statistically similar to those of the established devices. The Vascular Occlusion Test (VOT) provided a physiological process (ischemia and reperfusion) to evaluate dynamic changes, with the expectation that all devices would respond similarly.

8. Sample Size for the Training Set

The document does not specify any training set size or methodology. The Presygen™/si-1 is described as a non-contact oximeter based on multispectral optical imaging techniques, and the software performs calculations to derive StO2. While such a device would inherently have a model (algorithm) that was developed and potentially "trained" or optimized during its development, this 510(k) summary focuses on the validation data (performance testing and clinical studies) rather than the internal development or training of the core StO2 calculation algorithm. This is typical for a 510(k) where the focus is on post-development verification and validation for regulatory approval.

9. How the Ground Truth for the Training Set Was Established

Since no training set details are provided in the document, there is no information on how its ground truth was established.

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