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The SOZO Pro has the following uses:

For adult human patients at risk of lymphedema:

A bioimpedance spectroscopy device for use on adult human patients, utilizing impedance ratios that are displayed as an L-Dex ratio that supports the measurement of extracellular volume differences between the limbs and is presented to the clinician on an L-Dex scale as an aid to their clinical assessment of lymphedema.

The use of the device to obtain an L-Dex score is only indicated for patients who will have or who have had lymph nodes, from the axillary and/or pelvic regions, either removed, damaged or irradiated.

The SOZO Pro is intended for adult patients living with heart failure.

This device is intended for use, under the direction of a physician, for the 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 Pro may be used as an adjunct to existing methods by aiding clinicians who are using Subjective Global Assessment (SGA) tools to assess patients at risk of protein-calorie malnutrition (PCM).

The SOZO Pro may be further used to estimate the following body composition parameters in humans to track clinically relevant body composition parameters over time:

• Fat mass

• Fat-free mass

• Total body water

• Intracellular fluid

• Extracellular fluid

• Skeletal muscle mass

• The following outputs are also presented:

• Body Mass Index (BMI)

• Basal metabolic rate (BMR; based on Mifflin St. Jeor's algorithm) displayed in calories per day

• Protein and mineral (also known as 'dry lean mass') represents the content of a body that is not fat or fluid; calculated by subtracting total body water weight from fat-free mass weight.

The SOZO Pro device measures current (I), voltage (V) and phase angle (Phi), and from these values calculates resistance (R), reactance (Xc), and impedance (Z), which are used to estimate the above body composition parameters. The device' software will also display the Cole plot, subject height, weight, age and sex.

The SOZO Pro 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 cloud- hosted database. Patient weight is measured with load cells located in the SOZO Pro foot unit or can be hand entered.

Bioimpedance measurements require the patient's weight to be measured by a scale embedded in the base of the system or for the weight of the patient to be entered manually. Following the collection of the patient weight, the patient contacts the SOZO Pro with their bare hands and feet on stainless steel electrodes. The impedance measurement takes about 30 seconds, during which the SOZO Pro® system applies small levels of electrical energy (200μA RMS) to the body across 256 frequencies spaced from 3kHz to 1000kHz and measures the resulting voltage levels.

The provided text describes the SOZO Pro device, a bioimpedance spectroscopy device, and its 510(k) submission to the FDA. However, it does not contain the specific details about acceptance criteria, a comparative study with a human-in-the-loop, the exact sample sizes for test and training sets, the number and qualifications of experts for ground truth, or adjudication methods for all the stated indications for use.

Based on the information available, here's what can be extracted and inferred:

1. Table of Acceptance Criteria and Reported Device Performance

The document states that the device went through "appropriate testing per design controls to confirm functionality and performance of the indications." While specific numerical acceptance criteria (e.g., accuracy percentages, thresholds) are not explicitly provided in this document, the general categories of testing and the reported outcomes are:

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

• Test Set Sample Size: Not explicitly stated for any of the performance tests. The document mentions "fixed loads" for functional performance, implying a controlled, non-patient-specific test, and "a variety of pacemakers" for compatibility. For the software V&V, it states the software was "verified and validated," which implies testing, but sample size is not quantified.
• Data Provenance: Not explicitly stated. The document is a 510(k) summary for a device manufactured by ImpediMed Limited in Australia. The testing is likely conducted by the manufacturer, but the origin of the data used for performance comparison (e.g., patient data) is not specified. It does not indicate if it was retrospective or prospective.

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

• Not explicitly stated. The document focuses on technical performance and validation against engineering standards and a predicate device, rather than diagnostic accuracy studies involving expert human readers and a ground truth derived from clinical experts.

4. Adjudication Method for the Test Set

• Not applicable/Not explicitly stated. Since there's no mention of a human-in-the-loop diagnostic study or expert consensus for ground truth establishment, adjudication methods are not detailed.

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

• No, not explicitly stated or implied. The submission emphasizes substantial equivalence to a predicate device primarily through technical and functional comparisons, not through a comparative effectiveness study showing improvement in human reader performance with AI assistance. The document states, "The SOZO Pro is intended for use, under the direction of a physician, for the monitoring of patients with fluid management problems suffering from heart failure. Data from the device should be considered in conjunction with other clinical data." This indicates it's an aid, not a standalone diagnostic that would typically undergo such a comparative study for its primary clearance.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

• Yes, implied. The "Functional performance" section, where it states "performance testing was undertaken using fixed loads and comparing modified SOZO Pro to predicate SOZO measurements to demonstrate that outputs remained consistently accurate and precise," suggests standalone performance evaluation. The device measures impedance, resistance, reactance, and then calculates body composition parameters. The validation of these calculations against a known standard (fixed loads, predicate device performance) represents a standalone performance assessment.

7. The Type of Ground Truth Used

• Reference to Predicate Device and Engineering Standards: For most of the performance claims, the ground truth appears to be:

  • The performance of the predicate SOZO device (K203473).
  • Compliance with IEC 60601 (Electrical Safety/EMC), ISO 62304 (Software V&V), ISO 10993 (Biocompatibility), NIST Handbook 44 and EU Directive 2014/31/EU (Weight Scale).
  • Fixed loads for functional performance testing.
  • ISO 14117 for pacemaker/ICD compatibility.

  There is no mention of "expert consensus," "pathology," or "outcomes data" as ground truth for the device's diagnostic or monitoring capabilities beyond aiding clinical assessment.

8. The Sample Size for the Training Set

• Not applicable/Not stated. This device does not appear to be an AI/ML device that requires a distinct "training set" in the conventional sense for a deep learning model. It's a bioimpedance spectroscopy device that measures physical parameters and applies algorithms (e.g., Mifflin St. Jeor for BMR). The "software updates were included to integrate the scale and weight measurement capabilities," but this doesn't imply a self-learning algorithm that would require a training dataset.

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

• Not applicable. As it does not appear to be an AI/ML device with a training set, this information is not relevant or provided. The algorithms it uses (e.g., for body composition) are likely fixed formulas validated against general physiological principles and existing scientific literature.

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The SOZO Pro has the following uses:

For adult human patients at risk of lymphedema:

A bioimpedance spectroscopy device for use on adult human patients, utilizing impedance ratios that are displayed as an L-Dex ratio that supports the measurement of extracellular volume differences between the limbs and is presented to the clinician on an L-Dex scale as an aid to their clinical assessment of lymphedema.

The use of the device to obtain an L-Dex score is only indicated for patients who will have or who have had lymph nodes, from the axillary and/or pelvic regions, either removed, damaged or imadiated.

The SOZO Pro 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 cloud- hosted database. Patient weight is measured with load cells located in the SOZO Pro foot unit or can be hand entered.

Bioimpedance measurements require the patient's weight to be measured by a scale embedded in the base of the system or for the weight of the patient to be entered manually. Following the collection of the patient weight, the patient contacts the SOZO Pro with their bare hands and feet on stainless steel electrodes. The impedance measurement takes about 30 seconds, during which the SOZO Pro® system applies small levels of electrical energy (200µA RMS) to the body across 256 frequencies spaced from 3kHz to 1000kHz and measures the resulting voltage levels.

This FDA 510(k) summary doesn't provide detailed information on specific acceptance criteria and a comprehensive study designed to prove the device meets those criteria in terms of clinical performance. Instead, it focuses on verifying the modifications to an existing predicate device (SOZO) by showing that the new device (SOZO Pro) still performs comparably and meets regulatory standards for safety and fundamental performance.

Here's an analysis based on the provided text, highlighting what is and isn't available:

Acceptance Criteria and Reported Device Performance

The document does not present a formal table of clinical performance acceptance criteria and reported results. The "Performance Data" section primarily addresses engineering and regulatory compliance rather than direct clinical efficacy for its intended use (aid in clinical assessment of lymphedema).

The closest indications of acceptance criteria and performance relate to engineering and regulatory standards:

Missing Information (and likely not present in a 510(k) Special submission for this type of modification):

The 510(k) Special is for modifying an existing cleared device. Therefore, a new, comprehensive clinical study demonstrating the clinical effectiveness of the L-Dex ratio itself (which was established for the predicate device) is usually not required. The focus is on showing the modifications do not negatively impact the established performance.

1. Sample size used for the test set and the data provenance: Not explicitly stated for clinical performance as clinical effectiveness was likely established with the predicate device. For functional performance, "fixed loads" were used, implying a lab-based test, not a patient test set.
2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable as this 510(k) does not describe a clinical ground truth establishment study.
3. Adjudication method: Not applicable.
4. Multi-reader multi-case (MRMC) comparative effectiveness study: Not applicable. The device provides a quantitative L-Dex ratio, not an image for interpretation by multiple readers.
5. Standalone (algorithm-only) performance: The device is a standalone algorithm that provides an L-Dex score. Its performance in generating this score consistently is implied by the functional testing ("outputs remained consistently accurate and precise").
6. Type of ground truth used (expert consensus, pathology, outcomes data, etc.): For the clinical use of the L-Dex ratio as an aid in lymphedema assessment, this ground truth would have been established with the predicate device and is not detailed here. The current submission focuses on engineering verification.
7. Sample size for the training set: Not applicable. This device uses a bioimpedance spectroscopy algorithm to derive an L-Dex ratio, not a machine learning model that typically requires a clinical training set in the sense of AI/deep learning. The "algorithm" here is physics-based.
8. How the ground truth for the training set was established: Not applicable for the reasons above.

In summary: The provided 510(k) summary focuses on demonstrating that the modifications to the SOZO Pro (weight scale, hardware, software integration) do not compromise the established safety and performance of the original SOZO device. It confirms compliance with various engineering and regulatory standards but does not re-evaluate the clinical efficacy of "L-Dex ratio as an aid to clinical assessment of lymphedema" through a new clinical trial, as that was likely part of the original predicate device's clearance.

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The SOZO Pro may be used as an adjunct to existing methods by aiding clinicians who are using Subjective Global Assessment (SGA) tools to assess patients at risk of protein-calorie malnutrition (PCM).

The SOZO Pro may be further used to estimate the following body composition parameters in humans to track clinically relevant body composition parameters over time:

• · Fat mass
• · Fat-free mass
• Total body water
• · Intracellular fluid
• · Extracellular fluid
• Skeletal muscle mass

The following outputs are also presented:

• · Body Mass Index (BMI)
• · Basal metabolic rate (BMR; based on Mifflin St. Jeor's algorithm) displayed in calories per day

• Protein and mineral (also known as 'dry lean mass') represents the content of a body that is not fat or fluid; calculated by subtracting total body water weight from fat-free mass weight.

The SOZO Pro device measures current (1), voltage (V) and phase angle (Phi), and from these values calculates resistance (R).

reactance (Xc), and impedance (Z), which are used to estimate the above body composition parameters. The device/ software will also display the Cole plot, subject height, weight, age and sex.

The SOZO Pro 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 cloud- hosted database. Patient weight is measured with load cells located in the SOZO Pro foot unit or can be hand entered.

Bioimpedance measurements require the patient's weight to be measured by a scale embedded in the base of the system or for the weight of the patient to be entered manually. Following the collection of the patient weight, the patient contacts the SOZO Pro with their bare hands and feet on stainless steel electrodes. The impedance measurement takes about 30 seconds, during which the SOZO Pro® system applies small levels of electrical energy (200µA RMS) to the body across 256 frequencies spaced from 3kHz to 1000kHz and measures the resulting voltage levels.

The provided text is a 510(k) summary for the ImpediMed SOZO Pro device. It describes the device, its indications for use, technological characteristics, and performance data to demonstrate substantial equivalence to a predicate device. However, it does not contain detailed information about specific acceptance criteria or a study proving the device meets those criteria, especially in the context of AI-driven performance or human reader improvement.

The "Performance Data" section primarily focuses on:

• Electrical safety/EMC: Tested according to IEC 60601 standards.
• Software V&V: Tested according to ISO 62304.
• Biocompatibility: Tested according to ISO 10993.
• Functional performance testing: "undertaken using fixed loads and comparing modified SOZO Pro to predicate SOZO measurements to demonstrate that outputs remained consistently accurate and precise." This is high-level and lacks specifics on metrics or thresholds.
• Weight Scale Verification: Performed according to NIST Handbook 44 and EU Directive 2014/31/EU.

Since the provided document does not include the specific details you've requested regarding acceptance criteria and performance study for, for example, an AI component's diagnostic accuracy, human-in-the-loop performance, or detailed ground truth establishment, I cannot populate all sections of your request.

Based on the available information, here is what can be inferred and what is explicitly missing:

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

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

• Sample Size (Test Set): Not specified. The document mentions "fixed loads" for functional testing and a comparison to the predicate device, but no human subject test set size for evaluating body composition parameters is detailed.
• Data Provenance: Not specified. It's likely the testing occurred during device development/modification.

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

• Not applicable/Not specified. The testing described focuses on engineering/functional validation (electrical, software, biocompatibility, scale accuracy, and comparison to predicate measurements using fixed loads), not on establishing diagnostic ground truth from human data for body composition parameters. The device provides "estimates" and tracks parameters over time, suggesting its performance is validated against its own internal consistency or engineering standards rather than external "expert" ground truth for individual body composition values in a clinical diagnostic sense based on this document.

4. Adjudication method for the test set:

• Not applicable/Not specified.

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 a Bioimpedance Spectroscopy (BIS) device for body composition analysis, not an AI-assisted diagnostic imaging device requiring human reader interpretation or MRMC studies. The document does not describe any AI component that would require human-in-the-loop evaluation for diagnostic improvement.

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

• The "Performance Data" section discusses "functional performance testing" using "fixed loads" and comparison to the predicate device, which would be a form of standalone performance evaluation for the device's measurement capabilities.
• The software V&V confirms the software meets acceptance criteria and performs as intended.
• However, specific standalone accuracy metrics (e.g., against a gold standard for body composition in human subjects) are not provided in this summary.

7. The type of ground truth used:

• For electrical, software, biocompatibility, and scale testing: Engineering standards, established regulatory requirements, and fixed measurement loads act as "ground truth."
• For "functional performance testing" of body composition outputs: The "ground truth" used was a comparison to the predicate SOZO measurements and "fixed loads" to ensure "consistently accurate and precise" outputs. There is no mention of a clinical gold standard (e.g., DEXA, whole-body MRI, dilution methods) used as ground truth for the body composition parameters in human subjects for this specific K-summary documentation.

8. The sample size for the training set:

• Not applicable/Not specified. This document describes a medical device, not an AI model that undergoes "training" in the machine learning sense with a distinct training dataset. The device measures bioimpedance and calculates parameters using established physiological models and algorithms.

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

• Not applicable. As above, this is not an AI model that undergoes training on a dataset with external ground truth. The device relies on biophysical principles and algorithms for its calculations.

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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 (200uA RMS) to the body across 256 frequencies spaced from 3kHz to 1000kHz and measures the resulting voltage levels.

The provided text is a 510(k) summary for ImpediMed Limited's SOZO device. It outlines the regulatory review process, device description, technological characteristics, and performance data. However, it does not contain the specific details about acceptance criteria, the study design (like sample sizes for test and training sets, data provenance), ground truth establishment, expert qualifications, or MRMC comparative effectiveness studies that would typically be found in a clinical study report or a more detailed performance section of a 510(k) submission.

The document primarily focuses on demonstrating substantial equivalence to a predicate device (ImpediMed Limited's SOZO, K193410) through technical and safety testing, rather than a clinical performance study evaluating the diagnostic accuracy or effectiveness of a new AI-driven diagnostic feature.

The key change described in this 510(k) is a software modification: "Modification to SOZOapp Fluid Analysis module, renaming it as the 'HF-Dex' module and incorporating a set of normative reference ranges to aid the clinician in their fluid management of patients living with heart failure." This suggests the change is primarily about presenting existing data with new reference points for clinical interpretation, not necessarily about a new algorithm for fluid analysis that would require extensive clinical validation as requested in the prompt.

Given the information provided, I cannot fulfill all parts of your request. The document describes:

• Performance Data in general terms: "The SOZO system has gone through appropriate testing per design controls to confirm functionality and performance of the indications." This refers to:
  • Electrical safety/EMC (IEC 60601)
  • Software V&V (ISO 62304)
  • Biocompatibility (ISO 10993)
  • Functional performance: "performance testing was undertaken using both fixed loads and human volunteers comparing modified to predicate SOZO measurements to demonstrate that outputs remained consistently accurate and precise." This last point is the closest to a performance study, but it's focused on accuracy and precision of measurements (bioimpedance parameters, extracellular fluid, intracellular fluid, and total body water) compared to the predicate device, not on the diagnostic accuracy of the "HF-Dex" module for managing heart failure fluid.

Therefore, many sections of your request cannot be answered from the provided text.

Here's what can be extracted and inferred, along with the limitations:

1. A table of acceptance criteria and the reported device performance:

The document broadly states: "The software was verified and validated to meet acceptance criteria and perform as intended." And for functional performance: "to demonstrate that outputs remained consistently accurate and precise." However, specific quantitative acceptance criteria and the corresponding reported numerical performance (e.g., specific accuracy percentages, precision values, or ranges) are not provided.

Missing Information for a Detailed AI/Diagnostic Performance Study:

Since the document describes a software modification primarily related to displaying normative reference ranges and not a new diagnostic algorithm requiring an AI performance study, the following information is not present:

2. Sample size used for the test set and the data provenance: Not applicable in the context of this 510(k) summary, as it doesn't describe a clinical performance study for a new diagnostic algorithm. The "human volunteers" for functional performance testing are mentioned, but no sample size or provenance is given.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable, as there's no diagnostic test set with ground truth described.

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. This change isn't an AI-assistance feature in the sense of image interpretation or complex diagnostic aid, but rather new reference ranges for an existing measurement.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. The "HF-Dex" module seems to be a display enhancement to an existing measurement device, and its performance is tied to the underlying bioimpedance measurements, which are assessed against the predicate's measurement accuracy, not as a standalone diagnostic algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.): For the functional performance of the bioimpedance measurements, the ground truth indirectly relies on the established accuracy and precision of the predicate device (K193410) and potentially comparison to known physical properties via "fixed loads." For the "HF-Dex" module providing normative ranges, the "ground truth" would be the clinical standard or source of those normative ranges, which is not detailed here.

8. The sample size for the training set: Not applicable. This document does not describe a machine learning algorithm that requires a training set. The "HF-Dex" module incorporates "normative reference ranges," which implies pre-defined medical standards or clinical data, not a learned model from a training set.

9. How the ground truth for the training set was established: Not applicable.

In summary, this 510(k) notification focuses on demonstrating that modifications to an existing device (SOZO) – specifically, a software update incorporating new normative reference ranges – do not raise new safety or effectiveness concerns and maintain substantial equivalence to the predicate. It does not describe a clinical performance study of a new diagnostic algorithm involving AI or a comprehensive test set with established ground truth as you've outlined in your request.

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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

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.

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The SOZO system may be used as an adjunct to existing methods by aiding clinicians who are using Subjective Global Assessment (SGA) tools to assess patients at risk of protein-calorie malnutrition (PCM).

The SOZO system may be further used to estimate the following body composition parameters in humans to track clinically relevant body composition parameters over time:

• Fat mass
• Fat-free mass
• Total body water
• Intracellular fluid
• Extracellular fluid
• Skeletal muscle mass

The following outputs are also presented:

• Body Mass Index (BMI)
• Basal metabolic rate (BMR; based on Mifflin - St. Jeor's algorithm) displayed in calories per day
• Protein and mineral (also known as 'dry lean mass') represents the content of a body that is not fat or fluid; calculated by subtracting total body water weight from fat-free mass weight.

The SOZO device measures current (I), voltage (V) and phase angle (Phi), and from these values calculates resistance (R), reactance (Xc), and impedance (Z), which are used to estimate the above body composition parameters. The device/software will also display the Cole plot, subject height, weight, age and sex.

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 ("SOZOhub") contained within the hospital/facility network.

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 current (200µA RMS) to the body across 256 frequencies spaced logarithmically from 3kHz to 1000kHz and measures the resulting voltage levels. Established algorithms are used to analyze data and calculate various body composition parameters and present the outputs for the clinician to review.

Here's an analysis of the acceptance criteria and study information provided in the document:

1. Table of Acceptance Criteria and Reported Device Performance

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

The document does not explicitly state a specific "test set" sample size for a clinical study to directly prove the new indications for use. Instead, it states: "Clinical testing: clinical studies have identified the applicability of ImpediMed's BIS technology to act as an aid in body composition." This general statement implies that the underlying Bioimpedance Spectroscopy (BIS) technology has been validated through clinical studies, but it doesn't provide details about studies specific to the SOZO system's new indications or a dedicated test set with sample size.

For the comparative performance with the predicate device, a "test fixture" was used with "multiple fixed impedance loads," which isn't a human sample size but rather an engineering test.

Data Provenance: Not explicitly stated for specific clinical studies, only generally refers to "clinical studies."

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

This information is not provided in the document. The document refers to "clinical studies" for the applicability of BIS technology but does not detail how ground truth was established for these studies, nor the number or qualifications of experts involved.

4. Adjudication Method for the Test Set

This information is not provided in the document.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of Improvement with AI vs. Without AI Assistance

No MRMC study is mentioned in the document. The SOZO system is a device for measuring body composition parameters, not an AI-assisted diagnostic tool for human readers in the traditional sense of an MRMC study. Its use is described as "an adjunct to existing methods by aiding clinicians who are using Subjective Global Assessment (SGA) tools," but no study comparing human performance with and without SOZO assistance is described.

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

The device itself is a standalone measurement system that takes raw electrical measurements and processes them using "established algorithms" to calculate body composition parameters. The "comparative performance vs. predicate device" test (r > 0.99 correlation) can be considered a standalone performance assessment against a validated reference.

7. The Type of Ground Truth Used

• For Body Composition Parameters: The document states that "established algorithms are used to analyze data and calculate various body composition parameters." For the "comparative performance vs. predicate device," the predicate device (SFB7) is essentially the reference standard (ground truth surrogate). However, for the initial validation of the BIS technology to derive these parameters, it is generally understood that such systems are validated against gold standard body composition assessment methods (e.g., DEXA, isotope dilution, direct chemical analysis), though this specific detail is not provided for the SOZO system in this document. The document refers to "clinical studies have identified the applicability of ImpediMed's BIS technology to act as an aid in body composition," implying prior validation work.
• For Protein-Calorie Malnutrition (PCM) Assessment: The device is used as an adjunct to Subjective Global Assessment (SGA) tools, implying that SGA is the primary assessment method clinicians use.

8. The Sample Size for the Training Set

No training set sample size is explicitly mentioned. The device uses "established algorithms," suggesting that the algorithms were developed and potentially trained on datasets prior to this submission. This document focuses on the performance and equivalence of the SOZO device itself, not the detailed development of its underlying algorithms.

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

This information is not provided in the document. As with the training set size, the document does not delve into the historical development and validation of the "established algorithms" that process the bioimpedance data.

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For adult human patients at risk of lymphedema:

A bioimpedance spectroscopy device for use on adult human patients, utilizing impedance ratios that are displayed as an L-Dex ratio that supports the measurement of extracellular volume differences between the limbs and is presented to the clinician on an L-Dex scale as an aid to their clinical assessment of lymphedema.

The use of the device to obtain an L-Dex score is only indicated for patients who will have or who have had lymph nodes, from the axillary and/or pelvic regions, either removed, damaged or irradiated.

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 ("SOZOhub") contained within the hospital/facility network.

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. Established algorithms are used to analyze data and calculate extracellular fluid impedance levels for left and right limbs, and present the impedance ratio as an L-Dex® score for the clinician to review. This score facilitates their clinical assessment of lymphedema in adult human patients.

The SOZO® device is a bioimpedance spectroscopy device intended for adult human patients at risk of lymphedema. It uses impedance ratios to display an L-Dex ratio, aiding clinicians in assessing lymphedema by measuring extracellular volume differences between limbs.

Here's an overview of the acceptance criteria and the study proving the device meets them:

1. Acceptance Criteria and Reported Device Performance:

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

The document does not explicitly state a specific sample size for the "clinical testing" mentioned, nor does it detail the provenance (country of origin, retrospective or prospective) of the data used for establishing the strong correlation of extracellular fluid levels. For the "comparative performance vs. predicate device" test, the "test set" consisted of a test fixture creating "multiple fixed impedance loads representing different 'humans'".

3. Number of Experts and Qualifications:

The document does not specify the number or qualifications of experts used to establish ground truth for any of the tests. For "clinical testing," it refers to "studies" that identified the applicability of the BIS technology, implying clinical expertise was involved in those studies, but no details are provided here.

4. Adjudication Method:

The document does not mention any adjudication method for establishing ground truth within the context of the provided performance data.

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

The document does not describe an MRMC comparative effectiveness study involving human readers with and without AI assistance. The device is presented as an "aid to their clinical assessment," suggesting a human-in-the-loop scenario, but no comparative effectiveness study of this nature is detailed.

6. Standalone (Algorithm Only) Performance Study:

A standalone performance study was conducted for the device. The comparative performance against the predicate device using a test fixture and the "clinical testing" demonstrating correlation of extracellular fluid levels support the algorithm's standalone performance in producing the L-Dex ratio.

7. Type of Ground Truth Used:

• For Electrical Safety/EMC, Software V&V, Biocompatibility, and Functional Performance, the ground truth was based on adherence to international standards and internal design specifications/requirements.
• For Clinical Performance, the ground truth seems to be implicitly derived from established clinical understanding of lymphedema and extracellular fluid levels, as evidenced by "studies (that) have identified the applicability of ImpediMed's BIS technology." While not explicitly stated as "expert consensus," the nature of clinical assessment of lymphedema often relies on expert judgment integrated with objective measures.
• For Comparative Performance vs. Predicate Device, the ground truth was established by comparing the SOZO system's outputs against the outputs of already established predicate devices (ImpediMed U400 and SFB7) when presented with the same "fixed impedance loads." This implies the predicate devices' outputs served as the reference or "ground truth" for correlation.

8. Sample Size for the Training Set:

The document does not explicitly mention a separate "training set" or its sample size. The "Established algorithms are used to analyze data" implies algorithms were developed and likely trained, but details about the training process are not provided in this summary.

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

This information is not provided in the document.

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The SOZO Fluid Status Monitor 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 ("SOZOhub") contained within the hospital/facility network.

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 measures small quantities of electrical energy (200uA RMS) across 256 frequencies, spaced logarithmically from 3kHz to 1000kHz. Established algorithms are used to analyze data and calculate extracellular fluid impedance levels for left and right sides of the body, and present the impedance levels for the clinician to review. These scores facilitate the clinician's monitoring and management of patients with fluid management problems in a variety of medically accepted clinical applications.

The provided text is a 510(k) Summary for the ImpediMed SOZO™ system. While it details the device's technical characteristics, intended use, and various validations (electrical safety, software V&V, biocompatibility, functional performance), it does not contain a specific performance study with acceptance criteria and reported device performance for its primary intended use of monitoring fluid status in heart failure patients.

The document focuses on demonstrating substantial equivalence to a predicate device (ImpediMed Limited's IMED-Z, K142503) by highlighting similar technological characteristics and showing that minor differences do not raise new safety or effectiveness issues.

Here's a breakdown of what is and isn't available based on the provided text:

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

The document mentions "Comparative performance" but this is for demonstrating correlation between the new SOZO system and the predicate IMED-Z system using a "test fixture" (not human subjects).

Missing Information (Crucial for its Primary Indication):

The document does not provide acceptance criteria or performance data for the SOZO system's ability to accurately monitor fluid status in heart failure patients in a clinical setting. It states the purpose of the 510(k) is to clear design changes and indications, and relies on the "substantial equivalence" framework without presenting new clinical performance data for its intended use.

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

• Test set for fluid status monitoring: Not applicable, as no human subject clinical performance study is described for its intended use.
• Comparative performance (test fixture): The "test fixture" represents "multiple fixed impedance loads," but the exact number of these simulated 'humans' or specific impedance loads is not stated. This is an engineering verification, not a clinical test.

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

Not applicable, as no human subject clinical performance study is described. The "ground truth" for the comparative performance was the output of the predicate/reference device on a test fixture.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

Not applicable, as no human subject clinical performance study is described.

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 device is a bioimpedance measurement system that directly provides impedance levels, not an AI-assisted diagnostic tool interpreted by human readers in the sense of an MRMC study.

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

The device itself is a standalone measurement device. The "Comparative performance" section is the closest to a standalone evaluation, comparing the SOZO's output to another device's output on a test fixture. This is an algorithm-only comparison, but not against a clinical "ground truth" for fluid status monitoring.

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

For the comparative performance: The "ground truth" was the measurements from the predicate/reference device (IMED-Z/ZOE) on a test fixture. This is a technical (device vs. device) comparison, not a clinical ground truth (e.g., fluid volume measured by another gold standard method, or clinical outcomes).

8. The sample size for the training set:

Not applicable. This device is described as using "Established algorithms" to analyze data and calculate impedance levels. It's not a machine learning model that would typically have a "training set" in the context of supervised learning for classification or prediction. The algorithms are based on bioimpedance principles rather than trained on a large dataset of patient outcomes.

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

Not applicable, as there is no mention of a training set for machine learning. The algorithms are described as "established" for bioimpedance analysis.

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A bioimpedance spectroscopy device for use on adult human patients, utilizing impedance ratios that are displayed as an L-Dex ratio that supports the measurement of extracellular fluid volume differences between the limbs and is presented to the clinician on an L-Dex scale as an aid to their clinical assessment of unilateral lymphedema of the arm and leg in women and the leg in men.

The device is only indicated for patients who will have or who have had lymph nodes, from the axillary and pelvic regions, either removed, damaged or irradiated.

SOZOhub PC software - a PC software package that is intended to be used only with the ImpediMed SOZO device for uploading data on to the PC from the SOZO device, processing and analyzing of bioimpedance measurements.

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 ("SOZOhub") contained within the hospital/facility network.

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 measures small quantities of electrical energy (200ua RMS) across 256 frequencies, spaced logarithmically from 3kHz to 1000kHz. Established algorithms are used to analyze data and calculate extracellular fluid impedance levels for left and right limbs, and present the impedance ratio as an L-Dex® score for the clinician to review. This score facilitates their clinical assessment of unilateral lymphedema of the arm and leg in woman, and the leg in men.

Here's an analysis of the provided text regarding the acceptance criteria and study proving the device meets those criteria, formatted to address your specific points.

First, it's important to note that the provided documentation is a 510(k) premarket notification letter and summary for the SOZO™ device, which is an Impedance Plethysmograph (specifically, a bioimpedance spectroscopy device for assessing lymphedema). This type of submission primarily focuses on demonstrating substantial equivalence to a legally marketed predicate device, rather than proving efficacy through clinical trials with defined acceptance criteria and effect sizes as might be required for a PMA (Premarket Approval). Therefore, some of your requested information (e.g., effect size of human readers improving with AI, specific acceptance criteria for a clinical outcome, detailed ground truth establishment for a large test set) may not be present or applicable in this context.

The document emphasizes design changes to an existing technology (the L-Dex® U400) and the SOZO system's equivalence to that predicate. The "performance data" section primarily covers engineering and non-clinical testing.

Acceptance Criteria and Device Performance Study Analysis

1. Table of Acceptance Criteria and Reported Device Performance

The document does not present a formal table of "acceptance criteria" for clinical performance in the sense of a clinical trial. Instead, the performance data focuses on demonstrating that the new design of the SOZO system functions reliably and maintains characteristics similar to its predicate device. The "acceptance criteria" are implied by the successful completion of various engineering and non-clinical tests.

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

The provided text does not specify a sample size for a clinical "test set" involving human subjects for performance evaluation. The "comparative performance vs. predicate device" was conducted using a "test fixture to create multiple fixed impedance loads representing different 'humans'." This is a laboratory-based, non-clinical test.

• Sample Size for Test Set: Not applicable for a human clinical test set. The comparative test used a "test fixture" with "multiple fixed impedance loads."
• Data Provenance: The testing appears to be primarily laboratory-based, likely conducted by the manufacturer (ImpediMed Limited, Australia) or accredited third-party labs. It is not described as involving retrospective or prospective human clinical data.

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

This information is not applicable as the "test set" was not a human clinical dataset requiring expert interpretation. The ground truth for the device's measurements is based on the physical properties of the "fixed impedance loads" used in the test fixture.

4. Adjudication Method for the Test Set

Not applicable, as there was no human-interpreted test set requiring adjudication.

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

No, an MRMC comparative effectiveness study was not done. The device (SOZO) provides an L-Dex ratio, which is then used by a clinician as an "aid to their clinical assessment." This submission demonstrates the fidelity of the SOZO device's measurements compared to its predicate, not the impact on human reader performance. Therefore, there's no mention of an effect size for human readers improving with AI vs. without AI assistance because this is not an AI-based diagnostic tool in the sense that it provides an assessment directly to the clinician that then gets compared to human performance. It is a measurement device.

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

The device's core functionality is its standalone measurement capability. The "L-Dex ratio" is a direct output of the device's algorithms based on bioimpedance spectroscopy data. The comparative test against the predicate device using a test fixture effectively evaluates this "standalone" measurement performance in a controlled environment. The "very strong correlation (r > 0.99)" reported indicates its standalone performance similarity to the predicate.

7. The Type of Ground Truth Used

The "ground truth" for the comparative performance study was the known, "fixed impedance loads" created by the test fixture. This serves as a known standard against which the measurements of both the SOZO device and the predicate U400 system were compared.

8. The Sample Size for the Training Set

The document does not specify a sample size for a "training set." This is likely because the device is based on "established algorithms" (Section 3: Device Description) and bioimpedance spectroscopy principles, rather than a machine learning model that would typically require a distinct training dataset to learn patterns. The focus is on the hardware and software's ability to accurately apply these existing algorithms and measure bioimpedance correctly.

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

As there's no mention of a traditional "training set" for a machine learning model, the concept of establishing ground truth for it is not applicable in this document. The device relies on established scientific principles and algorithms for bioimpedance analysis, which were presumably developed and validated over time, but not detailed as a "training set" here.

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