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.

Device Description

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.

AI/ML Overview

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:

Acceptance Criteria (Generic/Inferred)	Reported Device Performance (as stated or inferred from "no failures")
Electrical Safety/EMC	Met IEC 60601 standards; CB certificate granted.
Software Verification & Validation	Met acceptance criteria and performed as intended (per ISO 62304).
Biocompatibility	Passed ISO 10993 testing; no failures reported.
Functional Performance	Outputs remained consistently accurate and precise (compared to predicate, using fixed loads) - Specific metrics or thresholds not provided.
Weight Scale Accuracy	Experienced no failures (per NIST Handbook 44/EU Directive).

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.

Summary

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May 4, 2023

ImpediMed Limited % Richard Hines Senior Manager of Regulatory Affairs 5900 Pasteur Court, Ste. 125 Carlsbad, CA 92008

Re: K230531 Trade/Device Name: SOZO Pro Regulation Number: 21 CFR§ 870.2770 Regulation Name: Impedance plethysmograph Regulatory Class: II Product Code: OJB, DSB, MNW Dated: April 7, 2023 Received: April 7, 2023

Dear Richard Hines:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies.

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You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-

information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Gema Gonzalez -S

Gema Gonzales, MS Acting Assistant Director DHT3A: Division of Renal, Gastrointestinal, Obesity and Transplant Devices OHT3: Office of GastroRenal, ObGyn, General Hospital and Urology Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510 (k) Number (if known) K230531

Device Name SOZO Pro

Indications for Use (Describe)

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.

Type of Use (Select one or both, as applicable)

× Prescription Use (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

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impedimed®

510(k) SUMMARY

ImpediMed SOZO Pro

Submitter

ImpediMed LimitedUnit 150 Parker CourtPinkenba, Qld 4008Australia
Phone:	760 585 2104
Facsimile:	760 804 9425
Contact Person:	Richard Hines
Contact Email:	rhines@impedimed.com
Date Prepared:	February 20, 2023
Name of Device:	SOZO Pro
Common or Usual Name	Body Fluid Analyzer
Regulation Number	21 CFR §870.2770
Regulation Name	Impedance Plethysmograph
Regulatory Class	II
Product Code:	QJB, DSB, MNW (Adjunct Monitor, Protein Calorie Malnutrition)
Predicate Device:	SOZO® (K190529)
Reference Device:	SOZO® (K193410)

Purpose of the Special 510(k) Notice

The purpose of the 510(k) is to clear the SOZO Pro device which is a modification of the predicate K190529 SOZO device to include a weight scale to allow for patient weights to be measured directly with the device, along with updates to the stand hardware and electrodes. Software updates were included to integrate the scale and weight measurement capabilities.

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Indications for Use

The SOZO Pro 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 Pro 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 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, age, and sex.

Device Description

Technological Characteristics

Bioimpedance spectroscopy is the technological principle for both the subject and predicate devices. The subject and predicate devices are based on the following same fundamental technological elements:

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o Use of electrodes to take measurements; two channels are used to measure each side of the body.

o Delivery of very low levels of current (200µA RMS) across 256 frequencies logarithmically spaced from 3kHz to 1000kHz.

o Measure patient weight, current (l), voltage (V) and phase angle (Ph) and calculates three bioimpedance parameters: impedance (Z), resistance (R) and reactance (Xc) to estimate extracellular fluid, intracellular fluid, and total body water.

ം Data is stored in and accessed from a cloud-based database (MySOZO) using a web browser interface. SOZO Pro is controlled through an Android app ("SOZOapp") on a supplied tablet, which is paired to the SOZO Pro hardware over Bluetooth connection and connects with the MySOZO database over Wi-Fi.

Performance Data

The SOZO Pro system has gone through appropriate testing per design controls to confirm functionality and performance of the indications.

Electrical safety/EMC: testing was performed according to the requirements set forth in IEC 60601 (subparts -1, -1-2, and -1-6). It was determined that the SOZO Pro device meets electrical safety and EMC requirements, and CB certificate was granted for the system.

Software V&V: the SOZO Pro same level of concern software documentation as the predicate device was created and testing performed in accordance with ISO 62304. The software was verified and validated to meet acceptance criteria and perform as intended.

Biocompatibility: testing was performed by an accredited third party according to the requirements set forth in ISO 10993 for a low risk, limited contact device. It was determined that the patient contact areas of SOZO Pro system passed biocompatibility testing with no failures reported as they are unchanged from the reference.

Functional 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.

Weight Scale Verification: Scale verification testing for SOZO Pro was performed in accordance with the NIST Handbook 44 (2022 Edition) and EU Directive 2014/31/EU for non-automatic weighing instruments. Scale verification testing experienced no failures.

Substantial Equivalence

The modified SOZO Pro has the same intended use and similar indications, principles of operation, and technological characteristics as its predicate device. The differences in the SOZO Pro device's technological characteristics to the predicate SOZO device do not raise any new questions of safety or effectiveness:

Conclusions

Testing discussed above demonstrates that the modified SOZO Pro device is as safe and effective and performs as well as or better than the predicate device.

Regulation Number and Section

§ 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.