(195 days)
The Paratrend 7+ System is intended to be used in the management of the critically ill patient by providing continuous blood gas data while permitting the simultaneous monitoring of blood pressure via an external transducer. The Paratrend 7+ Multiparameter Sensor is inserted via an intravascular access device into the vascular system (e.g. radial, femoral arteries). Within the United States market, the use of this device should be limited to 72 hours.
The Paratrend 7 Plus Sensor (MPS7004P) is a modified version of the currently legally marketed device, the Paratrend 7 sensor (MPS7004). The measurement of pO2 using an electrochemical sensor (Clark electrode) in the predicate Paratrend 7 sensor has been replaced in the Paratrend 7 Plus device by a sensor based on optical fibre/fluorescence quenching technology. All other measurement parameters are essentially unchanged. The telescopic introduction mechanism in the predicate Paratrend 7 sensor has been replaced by a rotary advancing mechanism. The application has been expanded to include venous access.
This document describes the Paratrend 7 Plus Multiparameter Sensor, a modified version of the Paratrend 7 sensor, intended for continuous blood gas monitoring in critically ill patients.
Here's an analysis of the provided information regarding acceptance criteria and the study:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state acceptance criteria in terms of specific performance thresholds for bias, precision, or correlation coefficients. Instead, it presents the approach taken to demonstrate "product accuracy claims" and "comparable results" to a predicate device.
The study aimed to show substantial equivalence to the predicate device, Paratrend 7, and its own previously cleared versions, as well as to Optex and Baxter Swan-Ganz systems.
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance (Summary) |
|---|---|---|
| Bias | Demonstrate comparable bias to predicate device and "actual" values. | Calculated (mean of differences between measured Paratrend 7 value and actual value). No specific values provided. Implied to be acceptable as "product accuracy claims" are satisfied. |
| Precision | Demonstrate comparable precision to predicate device. | Calculated (sample standard deviation of differences). No specific values provided. Implied to be acceptable as "product accuracy claims" are satisfied. |
| Correlation (Senior vs. Satellite systems) | Strong linear correlation between Senior and Satellite monitor readings. | "Good correlation" evident from linear regression analysis (correlation coefficients, line-intercept, line-gradient were recorded but not provided). |
| Statistical Difference (Senior vs. Satellite systems) | No significant difference at the 5% level. | "No significant difference at the 5% level" using a paired sample t-test. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not specify the exact sample size (number of measurements) used in the tonometer study. It mentions data collected "over the relevant range of gases."
- Data Provenance: The study was conducted by Diametrics Medical Limited, a UK-based company. The data appears to be prospective as it involves setting up tonometers and taking measurements with the device under review.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The ground truth in this study was established using precision gas mixtures and the Henderson-Hasselbalch equation to determine "actual" partial pressures and pH values in tonometers. This approach does not involve human experts establishing ground truth; it relies on established chemical and physical principles.
4. Adjudication Method for the Test Set
Not applicable. The ground truth was established by physical and chemical methods (tonometers with precision gas mixtures and calculation). There was no human interpretation or adjudication involved in determining the "actual" values.
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 an intravascular blood gas monitoring system, not an imaging or diagnostic device that involves human reader interpretation or AI assistance in that context. The study focuses on device performance against a controlled "actual" value.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The primary study described is a standalone performance evaluation of the device. The device's measurements (algorithm/sensor output) were compared to a known ground truth (tonometer values). Human "in-the-loop" performance in terms of interpretation or decision-making was not evaluated in this accuracy study, though the device's output is intended for use by clinicians.
7. The Type of Ground Truth Used
The ground truth used was physico-chemical ground truth, established by:
- Pre-equilibrated precision gas mixtures for "actual" partial pressures.
- Calculation using the Henderson-Hasselbalch equation for "actual" pH values.
8. The Sample Size for the Training Set
Not applicable. This document describes the performance evaluation of a medical device (sensor and monitor systems), not a machine learning or AI algorithm that typically requires a large training set. The device's measurement technology (fibre optic, fluorescence quenching, photometric absorption, thermocouple) is based on established physical and chemical principles, not on learned patterns from a training dataset.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no mention of a "training set" in the context of this device's development or evaluation.
§ 868.1170 Indwelling blood hydrogen ion concentration (pH) analyzer.
(a)
Identification. An indwelling blood hydrogen ion concentration (pH) analyzer is a device that consists of a catheter-tip pH electrode and that is used to measure, in vivo, the hydrogen ion concentration (pH) in blood to aid in determining the patient's acid-base balance.(b)
Classification. Class II (special controls). The special control for this device is FDA's “Class II Special Controls Guidance Document: Indwelling Blood Gas Analyzers; Final Guidance for Industry and FDA.”