OEM Electrode Body Fat Analyzer

This module measures body fat percentage by sending a low‑amplitude alternating current through multiple surface electrodes and analyzing the resulting bio‑impedance signal. The OEM version allows integrators to select electrode geometry, housing material, and signal‑processing firmware to match specific product requirements.

Working Principle

A sinusoidal current (typically 5 kHz–50 kHz) is injected via drive electrodes while sense electrodes capture the voltage drop. The impedance magnitude and phase at one or more frequencies are used to estimate extracellular and intracellular water volumes, which are then converted to body‑fat percentage using population‑specific equations. The front‑end includes a programmable gain amplifier and a 24‑bit sigma‑delta ADC to achieve sub‑0.1 Ω resolution.

Shielded twisted‑pair cables reduce external noise, and a driven‑right‑leg circuit improves common‑mode rejection. The algorithm compensates for skin temperature and electrode contact impedance via built‑in temperature sensors and a contact‑quality monitor.

Technical Specifications

Material Options

• Electrode metals: stainless steel 316L, gold‑plated brass, nickel‑free alloy, conductive polymer composite
• Housing plastics: ABS (UL‑94 V‑0), polycarbonate (UV‑stabilized), PEEK for high‑temperature environments
• Encapsulants: medical‑grade silicone gel, epoxy underfill for vibration resistance

Material selection influences electrode‑skin impedance, biocompatibility, and long‑term drift. Gold‑plated interfaces reduce oxidation‑related baseline shift, while conductive polymers provide flexibility for wearable form factors.

Design Features

Modular electrode array allows the integrator to choose spacing between 20 mm and 40 mm to match target segmental analysis (e.g., hand‑to‑foot, leg‑to‑leg). A built‑in multiplexer switches drive/sense pairs without external relays, minimizing component count.

On‑board temperature compensation uses two NTC sensors placed near the drive and sense electrodes. Firmware includes a contact‑quality flag that triggers a re‑measurement if impedance exceeds a programmable threshold, reducing false‑low readings caused by poor adhesion.

The PCB follows a four‑layer stack‑up with a dedicated ground plane under the analog front‑end, achieving >80 dB CMRR at 50 kHz. EMI filtering consists of a pi‑network (10 kΩ – 100 pF – 10 kΩ) on each signal line.

Applications

In fitness equipment, the analyzer provides segmental fat‑mass data that users can track over time, supporting personalized training programs. The OEM form factor permits integration into treadmill handles or bike consoles without adding noticeable bulk.

Clinical settings benefit from multi‑frequency capability, which enables estimation of intracellular water—a marker for edema or nutritional status. The module’s low power draw allows battery‑operated handheld devices for point‑of‑care assessments.

Research laboratories use the adjustable electrode spacing to study regional fluid shifts during exercise or dehydration studies. The digital I²C interface simplifies data logging alongside motion capture or metabolic cart systems.

Customization Options

• Electrode shape: disc, rectangular, or custom‑molded to fit ergonomic contours
• Cable length and termination: IDC, Molex, or JST connectors with optional strain relief
• Firmware: selectable algorithms (e.g., Lukaski, Deurenberg) or user‑provided calibration tables
• Housing color and labeling: silk‑screen logos, laser‑etched part numbers, or over‑molded soft‑touch grips

Each option is evaluated for impact on measurement repeatability; for instance, altering electrode spacing changes the sensitivity constant, which is compensated by a calibration factor stored in non‑volatile memory.

Quality Control

Every unit undergoes a four‑point impedance verification against precision resistive standards traceable to NIST. The test sequence includes open‑circuit, short‑circuit, and 500 Ω reference checks at each programmed frequency.

Environmental screening subjects samples to 85 % RH at 40 °C for 96 hours followed by functional testing to assess drift caused by moisture ingress. Mechanical vibration compliance follows IEC 60068‑2‑6 (10‑500 Hz, 0.5 g).

Final inspection reviews solder joint integrity via automated optical inspection and verifies firmware checksum before packaging. A batch‑level statistical process control chart tracks offset and gain variations to maintain a Cp > 1.33.

FAQ

Can electrode dimensions be customized?

Yes. Electrode diameter, shape, and spacing can be tailored to the ergonomics of the host device. Custom tooling costs are quoted after reviewing the supplied CAD model.

What information is needed for a quotation?

Required details include target measurement range, number of electrodes, preferred housing material, electrical interface (I²C/SPI), cable length, and any regulatory certifications (e.g., IEC 60601‑1) needed for the end product.

Which materials are available for biocompatible contact?

Medical‑grade stainless steel 316L, titanium nitride coating, and gold‑plated brass are standard options. Conductive polymer hydrogels are available for dry‑electrode wearable applications.

How is quality inspected?

Each lot receives impedance accuracy testing, temperature‑coefficient verification, and visual inspection. Environmental stress screening is performed on a sample basis per lot.

What packaging options are offered?

Units are shipped in anti‑static trays with desiccant, or in custom‑foam inserts for higher volume orders. Palletized shipments include humidity indicator cards.

Request a Quote

To discuss your specific integration needs, please provide the application details and desired specifications. Our engineering team will review the requirements and return a detailed proposal.