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The intended use of the Philips NM3 Respiratory Profile Monitor, Model 7900, is to provide:

• cardiac output monitoring via the method of partial rebreathing in adult patients receiving mechanical ventilation during general anesthesia and in the intensive care unit (ICU).
• spirometric, and carbon dioxide monitoring in neonatal, pediatric and adult patients during general anesthesia and in the intensive care unit (ICU) and the emergency department (ED). Separate combination CO2/flow sensors are provided for adult, pediatric and neonatal use.
• continuous, non-invasive monitoring of functional arterial oxygen saturation and pulse rate in neonatal, pediatric and adult patients during both no motion and motion conditions and for patients who are well or poorly perfused during general anesthesia and in the intensive care unit (ICU) and the emergency department (ED).
  The intended use of the VentAssist software option is to provide:
• non-invasive monitoring of work of breathing per minute in adult patients receiving pressure support mechanical ventilation.
• on-demand advice in mechanically ventilated adult patients as prescribed by the caregiver regarding (a) modifications to the current pressure support settings in order to assess the work of breathing and breathing pattern and (b) modifications to ventilation in order to maintain end-tidal CO2 in a range determined by the physician. The patients should be hemodynamically stable and must be breathing spontaneously.

The NM3 monitor with VentAssist is intended for non-invasive monitoring of the inspired and expired airflow and airway pressure of intensive care unit (ICU), anesthesia and emergency room (ER) patients, as well as capnography and pulse oximetry in all of these clinical settings. It is intended to serve all of the same purposes as the flow, carbon dioxide, pulse oximetry, and cardiac output monitoring components of the predicate NM3 monitor with the addition of the optional VentAssist software.
Combination CO2 adapter/flow sensors (neonatal, pediatric, adult), combination adult CO2 adapter/flow sensors with a partial rebreathing valve and flow sensors (infant/neonatal, pediatric/adult) are connected with a male pneumatic connector to the NM3 monitor. Sidestream airway adapters and nasal cannulas are available which are connected with a sample cell connector to a receptacle on the LoFlo Module which can be interfaced to the NM3 monitor. All of these sensors are already legally marketed as accessories of 510(k) cleared Respironics-Novametrix NM3 monitor. The pulse oximetry sensors are connected to the NM3 monitor via a connector on the front panel of the monitor. All of the pulse oximetry sensors are already legally marketed as accessories of the 510(k) cleared NM3 monitor and Masimo predicate devices.
The principal function of the flow portion of combination sensors and flow sensors is to provide a differential pressure signal related to flow and airway pressure relative to atmospheric pressure. These sensors are often placed in the breathing circuit between the endotracheal tube and the ventilator circuit Y piece and may also be used in conjunction with a face mask or mouthpiece. The flow measurement portion of the NM3 monitor consists of a microprocessor-based data acquisition system that measures flow, and pressure and interfaces with a Capnostat 5 CO2 sensor. The CO2 airway adapter portion of the combination sensors, allow the Respironics-Novametrix CO2 mainstream gas sensor, the Capnostal® 5, to attach to it and measure the concentration of CO2 in the airway using infrared technology. When CO2 measurements are combined with airway flow and volume measurements, other parameters such as CO2 production and dead space can be calculated in all patient populations. The Capnostat 5 sensor as a mainstream gas analyzer includes a sample cell positioned in the breathing circuit through which a patient's inspiratory and expiratory gases flow. The LoFlo module, a sidestream type of gas analyzer, samples gases at 50 ml/min from a sampling port in an adapter placed in a breathing circuit or from a nasal or oral cannula. The gas then passes through a sampling tube to the sample cell, where the gas components are measured. The combination adult CO2 adapter/flow sensors with a partial rebreathing valve with periodic activation of the rebreathing valve allow pulmonary capillary blood flow and cardiac output to be calculated using the differential Fick method.
The VentAssist software option comprises a new screen with a soft key that provides ondemand ventilator-independent open-loop advice with respect to the level of pressure support and ventilation. As an advisory system, the clinician can choose to accept or reject the advice, alleviating any issues of safety and effectiveness. Additionally, an improved method for the calculation of plateau pressure has been included, as well as a new calculated parameter for work of breathing (WOB). The WOB parameter facilitates the goal of reducing excessive work of breathing per minute, or power of breathing (WOB/min), for mechanical ventilatory support in patients with respiratory failure. The WOB/min parameter is implemented using an Artificial Neural Net (ANN) and is used by the PSV Advisor software. The VentAssist PS/V Advisor is a rule based system which provides on-demand advice for the setting of the PSV level and ventilator support levels, based upon WOB/min, breathing frequency, tidal volume, ideal body weight, and end-tidal CO2. The advice is based upon a set of logic rules developed and refined in conjunction with experienced critical care clinicians at teaching University hospitals. Decision support advice offered by the VentAssist software is available during monitoring of adult patients. The monitor uses the sensor-type (adult, pediatric, or neonate), as well as patient data entered into the monitor, to enable appropriate features.

Here's a breakdown of the acceptance criteria and study information for the Philips NM3 Respiratory Profile Monitor with VentAssist, Model 7900, based on the provided text:

Important Note: The provided 510(k) summary primarily focuses on establishing substantial equivalence to predicate devices and describes the validation of the Work of Breathing (WOB/min) parameter and the PS/V Advisor. It does not provide a detailed table of specific acceptance criteria with numerical thresholds for performance, nor does it present the study results in a quantitative manner against those thresholds. Most of the information below is extracted from the "Validation" section and related descriptions.

1. Table of Acceptance Criteria and Reported Device Performance

As mentioned, explicit numerical acceptance criteria are not provided in the document. The validation focuses on the accuracy of WOB/min and the agreement with PS Advisor recommendations.

• Agreement with esophageal pressure measurement (cleared device: Bicore CP-100)
• Bias and precision of invasive vs. noninvasive WOB/min |
• "Validating the front end for esophageal pressure measurement with a cleared device, Bicore CP-100 Cardiopulmonary Monitor"
• "Comparing invasive measurements of WOB/min using the esophageal balloon to noninvasive measures of WOB/min derived from proximal flow and airway pressure data... (bias and precision of 0.84 ±2.2 J/min)" |
  | VentAssist PS/V Advisor (Clinician Agreement) |
• Clinician agreement with recommendations (implicit: high degree of agreement expected) |
• Two clinical studies conducted. One study: "clinicians agreed with the PS Advisor recommendations." (Published in Banner et al, Chest, 133(3):697-703, 2008)
• Second study: "similar but done blinded so the clinician was unable to see the recommendations of the PS Advisor." (No specific results provided in this document for the second study) |
  | VentAssist PS/V Advisor (Safety & Effectiveness) |
• As an advisory system, safety and effectiveness are supported by the clinician's ability to reject advice |
• "clinician can choose to accept or reject the advice, alleviating any issues of safety and effectiveness." |
  | WOB/min Algorithm Implementation |
• Proper implementation in the embedded system |
• "Validating that the WOB/min algorithm was properly implemented in the embedded system, the Philips NM3 Monitor." |

2. Sample Size Used for the Test Set and Data Provenance

• WOB/min Validation: "ventilated adults in the ICU (MICU, CICU, SICU, burn unit, step-down unit) who were breathing spontaneously on pressure support ventilation."

  • Sample Size: Not explicitly stated.
  • Data Provenance: Prospective, collected from various ICU settings (MICU, CICU, SICU, burn unit, step-down unit). Country of origin is not specified but the context of "teaching University hospitals" for rule development suggests US-based.

• PS/V Advisor Clinical Studies:

  • Sample Size: Not explicitly stated for either study.
  • Data Provenance: Prospective, clinical studies. Country of origin not specified, but the context of "teaching University hospitals" for rule development suggests US-based. One study's results were published in "Banner et al, Chest, 133(3):697-703, 2008."

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications

• WOB/min Validation:

  • Number of Experts: Not applicable in the context of ground truth for this parameter. Ground truth was established by invasive esophageal balloon measurements.
  • Qualifications: "experienced critical care clinicians at teaching University hospitals" were involved in the development and refinement of the logic rules, not in establishing ground truth for the WOB/min measurement itself.

• PS/V Advisor Clinical Studies:

  • Number of Experts: Not explicitly stated for the test set evaluation. The text indicates that the advice was based on "logic rules developed and refined in conjunction with experienced critical care clinicians at teaching University hospitals." These clinicians likely acted as the "experts" whose judgment was compared against the device's advice.
  • Qualifications: "experienced critical care clinicians at teaching University hospitals." No specific years of experience are listed.

4. Adjudication Method for the Test Set

The document does not describe a formal adjudication method (e.g., 2+1, 3+1) for either the WOB/min validation or the PS/V Advisor studies.

• For WOB/min, the comparison was directly between the device's measurement and invasive (esophageal balloon) measurements.
• For the PS/V Advisor, the first study involved clinicians agreeing or disagreeing with the recommendations. The second study was blinded. This implies a direct comparison of the device's advice to clinical judgment.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done

• No, a formal MRMC comparative effectiveness study, as typically understood in medical imaging or diagnostic contexts, was not described.
• The clinical studies for the PS/V Advisor involved clinicians evaluating the device's recommendations, which could be seen as a form of human-in-the-loop assessment. However, the document does not quantify an "effect size of how much human readers improve with AI vs without AI assistance" in terms of specific performance metrics. It rather indicates that clinicians "agreed with the PS Advisor recommendations."

6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done

• Yes, for WOB/min calculation: The "noninvasive work of breathing per minute parameter" was validated by comparing its autonomously calculated values to invasive measurements (bias and precision of 0.84 ±2.2 J/min). This represents the standalone performance of the WOB/min module.
• No, for PS/V Advisor: The VentAssist PS/V Advisor is explicitly an "advisory system" where the "clinician can choose to accept or reject the advice." Its validation inherently involves human interaction (clinician agreement).

7. The Type of Ground Truth Used

• Work of Breathing Per Minute (WOB/min): The ground truth was invasive measurements of WOB/min using the esophageal balloon.
• VentAssist PS/V Advisor: The ground truth for evaluating the advice was the judgment/agreement of experienced critical care clinicians. The logic rules themselves were developed in conjunction with these experts.

8. The Sample Size for the Training Set

• WOB/min Artificial Neural Net (ANN): The sample size for training the ANN is not mentioned.
• VentAssist PS/V Advisor (Fuzzy Logic Rules): The document states the rules were "developed and refined in conjunction with experienced critical care clinicians." It does not specify a distinct "training set" of patients or cases used solely for this development, but rather implies an iterative process with clinical expert input.

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

• WOB/min Artificial Neural Net (ANN): How the ground truth for training the ANN was established is not provided. It's common for such ANNs to be trained on data where the output (WOB/min) is derived from invasive measurements using standard physiological models.
• VentAssist PS/V Advisor (Fuzzy Logic Rules): The ground truth for developing and refining the fuzzy logic rules was established through collaboration and consensus with experienced critical care clinicians at teaching University hospitals. This involved their expertise in defining appropriate PSV levels and ventilation adjustments based on various patient parameters (WOB/min, breathing frequency, tidal volume, ideal body weight, and end-tidal CO2).

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