(298 days)
The SOZO Body Fluid Analyzer is intended for adult patients living with heart failure.
This device is intended for use, under the direction of a physician, for the noninvasive monitoring of patients with fluid management problems suffering from heart failure. Data from the device should be considered in conjunction with other clinical data.
The SOZO system consists of a connected hand and footplate with built-in stainless steel electrodes, paired with an Android tablet over Bluetooth connection. An app ("SOZOapp"), supplied with the tablet, controls the functionality of the hardware and supplies the bioimpedance measurement data to a database ("MySOZO") managed on an external cloudhosted database.
Measurements require the patient to make contact with bare hands and feet on stainless steel electrodes. The measurement takes about 30 seconds, during which the SOZO™ system applies small levels of electrical energy (200µA RMS) to the body across 256 frequencies spaced logarithmically from 3kHz to 1000kHz and measures the resulting voltage levels.
The provided text describes the SOZO Body Fluid Analyzer and its clearance via a 510(k) premarket notification. The document focuses on showing substantial equivalence to a predicate device rather than presenting a detailed study proving device performance against specific acceptance criteria for heart failure monitoring. However, it does mention that "The SOZO system has gone through appropriate testing per design controls to confirm functionality and performance of the indications." and "The software was verified and validated to meet acceptance criteria and perform as intended."
Based on the provided text, a direct, comprehensive study with specific acceptance criteria and detailed performance metrics for the device's clinical indication (monitoring heart failure patients with fluid management problems) is not explicitly detailed. The document primarily focuses on demonstrating substantial equivalence through:
- Software V&V: "The software was verified and validated to meet acceptance criteria and perform as intended." - This refers to internal software development and testing, not a clinical performance study.
- Electrical safety/EMC: Tested per IEC 60601.
- Biocompatibility: Tested per ISO 10993.
- Functional performance: Tested design reliability by repeatedly placing weights.
Given the scope of the provided text, I cannot provide detailed acceptance criteria directly linked to clinical performance for heart failure monitoring, nor a study proving those criteria are met for the full clinical indication. The document states "Performance data demonstrates that the modified SOZO is as safe and effective as its predicate," but does not elaborate on what specific performance data was collected for heart failure monitoring.
Therefore, the following information is based on the limited details provided in the text regarding "acceptance criteria" and "performance," largely inferring from the context of a 510(k) submission focused on demonstrating substantial equivalence to a predicate device, rather than a de novo clinical validation for the heart failure indication against quantitative performance targets.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria (Inferred/Stated) | Reported Device Performance (as per document) |
|---|---|---|
| Software Validation | Software meets requirements and functions as intended. | "The software was verified and validated to meet acceptance criteria and perform as intended." |
| Electrical Safety/EMC | Compliance with relevant electrical safety and electromagnetic compatibility standards. | "Meets electrical safety and EMC requirements, and CB certificate was granted." (per IEC 60601) |
| Biocompatibility | Device materials are biocompatible for limited contact. | "Passed biocompatibility testing with no failures reported." (per ISO 10993) |
| Functional Reliability | Device remains functional throughout its intended life under physical stress. | "Expected to remain functional throughout its intended life." |
| Equivalence to Predicate | "As safe and effective" as the predicate device. | "Performance data demonstrates that the modified SOZO is as safe and effective as its predicate." |
| Cole Plot Grading Feature (New Feature) | Helps users assess the quality of the overall measurement. | Modification added; implies it functions as intended to assist in quality assessment. |
2. Sample size used for the test set and the data provenance
The document does not specify a distinct "test set" in the context of clinical performance data for heart failure monitoring. The performance data mentioned (software V&V, electrical safety, biocompatibility, functional performance) appear to be part of engineering design verification and validation processes. No clinical test set size or data provenance (e.g., country of origin, retrospective/prospective) for clinical effectiveness in heart failure monitoring is provided.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable as a clinical test set with externally established ground truth for heart failure monitoring is not described in the provided text.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable.
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 SOZO Body Fluid Analyzer is described as a non-invasive monitoring device for fluid management, not an AI-assisted diagnostic imaging tool that would typically involve human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
The device is a "Body Fluid Analyzer" that provides data "under the direction of a physician" and "in conjunction with other clinical data." This indicates it's a device intended for clinical use with human interpretation, not a standalone AI algorithm for diagnosis. The phrase "algorithm only" performance would not be directly applicable in the way it is for an AI-driven image analysis tool, for example.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
For the engineering and software validation, the 'ground truth' would be the design requirements and specifications themselves. For clinical performance related to its indication (monitoring fluid management in heart failure), the text does not specify how clinical ground truth was established, as it primarily relies on substantial equivalence to a predicate device rather than a new clinical trial.
8. The sample size for the training set
Not applicable. The document does not describe a machine learning model that would require a "training set" in the context of its primary claim, but rather a bioimpedance-based measurement device.
9. How the ground truth for the training set was established
Not applicable.
§ 870.2770 Impedance plethysmograph.
(a)
Identification. An impedance plethysmograph is a device used to estimate peripheral blood flow by measuring electrical impedance changes in a region of the body such as the arms and legs.(b)
Classification. Class II (special controls). The device, when it is a body composition analyzer which is not intended to diagnose or treat any medical condition, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.