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The device is indicated for use in mechanically ventilated neonate, infant and pediatic patients where the precise and direct measurement of oxygen uptake (VO2), carbon dioxide excretion (VCO2), resting energy expenditure (REE) and respiratory quotient (RQ) will allow the attending physician to plan and monitor an optimal nutrition regime for the patient in terms of substrate composition and utilization.

The NICU V'O2 device is an indirect calorimeter that allows accurate and precise quantification of oxygen consumption (V'O2), carbon dioxide excretion (V'CO2), resting energy expenditure (REE, the number of calories consumed per day) and respiratory quotient (RQ, the ratio of V'CO2 to V'O2) in mechanically ventilated patients. Patients include neonate, infant and pediatric patients with a body weight from 0.5 kg, low minute ventilation, high respiratory rate, and receiving fluctuating and/or elevated inspiratory oxygen concentrations.

The device functions by measuring oxygen concentration (using laser diode sensor technology) and carbon dioxide concentration (using NDIR infrared sensor technology) in inspired and expired gas as well as inspiratory flow. The inspiratory flowmeter (differential pressure type pneumotach) is attached at the patient inspiratory outlet of the ventilator. An inspiratory gas sample line is connected to the inspiratory limb of the patient breathing circuit, and an expiratory gas sample line is connected to the ventilator exhaust. The device automatically alternates between these two sample points.

Oxygen consumption is determined by comparing the amounts of oxygen in inspired and expired gas, and carbon dioxide excretion is determined by comparing the amounts of carbon dioxide in expired and inspired gas, respectively, per unit of time. These amounts are calculated from the primary measurements of oxygen and carbon dioxide concentrations and gas flow.

The resting energy expenditure (or resting metabolic rate), which is defined as the number of calories the body expends daily during resting conditions, is calculated from the values of oxygen consumption and carbon dioxide excretion using the modified Weir equation:

REE = (V'O2 x 3.941 + V'CO2 x 1.106) x 1440 kcal min / day L

Respiratory Quotient is calculated as the ratio of carbon dioxide produced by the patient to oxygen consumed by the patient.

The duration of measurement can be from tens of minutes to 24 hours, partly because the inspiratory flowmeter only sees dry gas and therefore does not significantly change calibration over time.

The device consists of two main components. An analyzer unit to which the patient is connected via gas sample and flowmeter pressure lines, and a computer running the dedicated software application under the Windows operating system. The software application works in conjunction with the hardware, and the computer presents in real time measured signals and computed physiological parameters, both as numeric and graphical data. The computer is the main control interface for the ICU staff using the device and offers options for offline data management.

The device is powered through an external medical AC/DC power supply.

The information provided describes the NICU V'O2 device, an indirect calorimeter for neonate, infant, and pediatric patients.

1. Table of acceptance criteria and the reported device performance:

2. Sample size used for the test set and the data provenance:

• Clinical Study (Test Set): The document states "An in vivo performance test was conducted in newborn patients". The exact number of patients (sample size) is not explicitly stated in the provided text.
• Data Provenance: The patients were "newborn patients" in a clinical setting. The country of origin is not specified. The study was prospective as it was an "in vivo performance test conducted in newborn patients".
• Animal Testing (Test Set): The document states "An in vivo performance test was conducted in animals to determine the accuracy of the V'O2 and V'CO2 measurements...". The exact number of animals is not explicitly stated, but it refers to "Sprague-Dawley rats". The study was prospective.
• Bench Testing (Test Set): Performed using a "lung simulator". This is an
  in vitro test, not involving human or animal subjects, hence no specific sample size for "test set" in the traditional sense, but rather a range of simulated conditions.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

• The ground truth for the clinical and animal studies was established using the Douglas Bag method, which is described as the "gold standard" for respiratory gas exchange.
• The document does not specify the number of experts or their qualifications involved in performing the Douglas Bag measurements or interpreting the results to establish the ground truth for the test set.

4. Adjudication method for the test set:

• The document describes comparing the NICU V'O2 device measurements directly against the "Douglas Bag gas collection as reference technique." This indicates a direct comparison to a gold standard, not a consensus-based adjudication among multiple reviewers. Therefore, no specific adjudication method like "2+1" or "3+1" was employed.

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. The NICU V'O2 device is an indirect calorimeter that directly measures physiological parameters. It is not an AI-assisted diagnostic tool that involves human readers interpreting images or data. Therefore, an MRMC comparative effectiveness study comparing human readers with and without AI assistance was not performed.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

• Yes, this was a standalone performance study. The device's measurements (V'O2, V'CO2, RQ, REE) were directly compared to the gold standard (Douglas Bag method) in both animal and clinical settings. The performance metrics (bias and precision) are reported for the device itself, indicating a standalone evaluation.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

• The ground truth used for both animal and clinical studies was the Douglas Bag gas collection method, which is considered the "gold standard" for respiratory gas exchange. This is a direct physiological measurement.

8. The sample size for the training set:

• The document does not mention a "training set" in the context of device development. This suggests the device's algorithms and parameters were likely validated through engineering and laboratory testing rather than machine learning on a distinct training dataset. The studies described are performance validation studies.

9. How the ground truth for the training set was established:

• As no "training set" for a machine learning algorithm is mentioned, this question is not applicable based on the provided information.

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