MedelOpt+ Infinity — A map of whole-brain activity — fNIRS and EEG in one headset
A lightweight exoskeleton headset with 16 near-infrared light sources, up to 32 detectors and 8 EEG electrodes. It shows which cortical areas are working during a task — from the prefrontal cortex to the cerebellum. You record in BIOPAC AcqKnowledge, together with signals from the body.
up to 252 channelstheoretically: 16 sources × 32 detectors
EEG 512 Hz8 electrodes in the same headset
up to 8 hoursof continuous recording
from age 4to adults — one adjustable headset
Light at 660 and 850 nm sources light up in turn · illustrative only
The top model of the MedelOpt+ family
Infinity: the most optodes in MedelOpt+ — in three configurations
Infinity is the top model in the MedelOpt+ family: up to 16 sources and 32 detectors, i.e. the most channels for whole-head mapping. For comparison, the mobile variant has 8 sources and up to 16 detectors. All Infinity models have 16 light sources; they differ in the number of detectors and the presence of EEG. More detectors mean more channels and denser head coverage. Sources and detectors can be purchased and added to the headset as your research grows.
INFIN+ 16-16
Whole-head fNIRS
Sources / detectors
16 / 16
EEG
—
Channels
128 theoretically
When the question concerns hemodynamics only, e.g. cognitive workload or task mapping.
INFIN+ 16-16 EEG
fNIRS + EEG
Sources / detectors
16 / 16
EEG
8 channels, 512 Hz
Channels
128 theoretically
Location and timing of activity in one recording — e.g. evoked potential paradigms with an fNIRS map.
INFIN+ 16-32 EEG
Highest density + EEG
Sources / detectors
16 / 32
EEG
8 channels, 512 Hz
Channels
252 theoretically
Whole-brain mapping and advanced montages with different depths.
the largest number of channels
Dots: illustrative layout — red sources, gray detectors, green EEG electrodes. Configurations and channel counts: biopac.com — MedelOpt+ Infinity.
cognitive neurosciencelanguage and hearingchild development from age 4gait and motor controlsocial interactionsports sciencevirtual realityepilepsy researchDBS and VNS stimulation
Infinity in the MedelOpt+ family
A different study scenario? The same technology in a different form
Mobility
Wireless, 8 sources and up to 16 detectors — for research on the move and in the field.
Tandem
Two synchronized headsets for hyperscanning and interaction research.
VR
Headset integrated with VR goggles, e.g. Meta Quest 3.
Infinity is the laboratory variant with the largest number of optodes. An overview of the whole MedelOpt+ platform and a comparison of variants: MedelOpt+ — fNIRS platform with EEG.
fNIRS and EEG in one headset
Light that shows where the brain is working
When an area of the cerebral cortex starts working harder, more oxygen-rich blood flows into it. fNIRS — functional near-infrared spectroscopy — measures this change with light, through the skin and skull, without needles and without a scanner. The MedelOpt+ Infinity headset does this over the whole head at once, and records EEG in the same device.
Each black “turret” with a colored marker is an optode: a light source or a detector. Infinity has up to 48 of them.
Emits
LEDs in the headset send light at two wavelengths deep into the head: 660 and 850 nm. In this range skin and bone are partially transparent to light.
Receives
Light scatters in the tissue, and part of it returns to the surface a few centimeters away. A detector waits there. A source–detector pair is one measurement channel.
Calculates
Hemoglobin with oxygen (HbO) and without oxygen (HbR) absorbs the two wavelengths differently. From the difference, the software calculates how the amount of each changes at a given location — a trace of the work of the cortex under the channel.
And alongside — EEG
Eight electrodes in the same headset record the electrical activity of the brain 512 times per second. According to BIOPAC, fNIRS better indicates where activity occurs, and EEG — when. MedelOpt+ combines both advantages.
Separation determines depth
In the Infinity headset you set the source–detector separation from 20 to 50 mm. Move the detector and see how the light path changes.
20 mm50 mm
The light arc reaches the cortex — the channel measures changes in the brain, but also in the skin above it.
Cross-section and light path — illustrative (layer proportions and depths are schematic). Separation range 20–50 mm and wavelengths 660/850 nm: biopac.com — MedelOpt+ Brain-Body Platform.
What exactly each channel records
The task begins — oxygenated blood flows in
A typical response under a channel over a working area: within a few seconds of the task onset, the concentration of oxygenated hemoglobin (HbO) rises, and that of deoxygenated hemoglobin (HbR) falls slightly. After the task, both signals return to baseline. Infinity records this time course simultaneously for hundreds of channels across the whole head.
HbO — oxygenated hemoglobinHbR — deoxygenated
Illustrative graph — the shape of a typical hemodynamic response, no scale. Principle of HbO and HbR measurement: BIOPAC MedelOpt+ (product sheet, 11/2025).
Live map · fNIRS Channel Monitor
The whole head on one screen
In AcqKnowledge each channel sits on a head map in the 10-10 system. During recording you see where HbO rises, where HbR falls and whether all sources and detectors are working properly — before you waste a session.
Screenshots: BIOPAC, AcqKnowledge fNIRS Channel Monitor with data from the MedelOpt+ headset (biopac.com — MedelOpt+ Infinity).
An exoskeleton instead of a cap
One headset for the whole head — and for every head
The optodes and electrodes are not sewn into a fabric cap but mounted in a lightweight, adjustable frame. This way they land in the same positions across participants and sessions, and the skin between them remains accessible. Click the points on the photo.
1
Optodes: sources and detectors
Up to 16 sources — LEDs emitting at 660 and 850 nm — and up to 32 detectors, i.e. sensitive silicon photodiodes with a preamplifier.
2
Free sockets
You move or add sources and detectors. This changes channel density, the 20–50 mm separations and the measurement area — from the whole head to a selected part of the cortex.
3
Access to the scalp
The open design lets you part the hair under the optodes without removing the headset — hair is the most common obstacle in fNIRS research.
4
Spine and nose clip
Fixed reference points on the face and the top of the head. With the MeMoSoft software, optodes land in the planned positions with an average accuracy of ±2.9 mm — according to BIOPAC, about five times more accurate than with a cap.
5
Circumference adjustment
A strap with a measuring scale fits the same headset to the head of a child from age 4 and to the head of an adult. You don’t buy separate sizes.
6
Electronics module
A small 22 × 85 × 48 mm box, powered with 5 V via micro USB. Infinity runs tethered to a computer; with the Mobility Pack (mini PC with battery) it becomes a mobile system.
up to 8 hof continuous recording — pressure distributed evenly around the head
SNR ≈ 151:1signal-to-noise ratio; electronics noise approx. 0.3% of the sensor range
6 h without driftfNIRS stability confirmed according to MEDPHOT criteria
EEG 24-bit8 channels + reference electrode and active ground, input noise approx. 1 µVpp
MedelOpt+ runs natively in AcqKnowledge — the BIOPAC software in which laboratories around the world record physiological signals. One interface controls the headset and all connected BIOPAC amplifiers, and fNIRS, EEG and body signals sit on one timeline.
MedelOpt+ supported from AcqKnowledge 6.0.2ACQ · MAT · EDF · SNIRF exportno external synchronization scripts
Sensor layout for your research question
The MeMoSoft program (MedelOpt Montage Software) generates the montage: EEG only, fNIRS only or a hybrid layout — and shows where to plug in each optode.
Areas from forehead to occiput — prefrontal, parietal, temporal and occipital cortex, down to the cerebellum, or the whole head.
MeMoSoft positions in AcqKnowledge — in the screenshot: each source–detector pair with its distance and 10-10 position; placement accuracy ±2.9 mm.
Calibration under control — before recording you check the signal from each source and detector.
Brain and body live, in one window
In the AcqKnowledge screenshot: EEG and fNIRS (HbO, HbR) from the headset, plus heart rate from a PPG sensor and skin conductance (EDA) from BIOPAC — in one file, on one timeline.
fNIRS Channel Monitor — live view of sources, detectors, and HbO and HbR on a 10-10 montage map.
Common start and stop — one click starts the headset and the amplifiers; events are marked automatically.
Stimuli from the same program — the AcqKnowledge stimulus presentation module, plus visual, auditory, electrical, tactile, olfactory and thermal stimulation.
Video and audio — a recording of participant behavior synchronized with the signals.
A common clock instead of scripts
A common clock and hardware synchronization eliminate delays, drift and frequency mismatches between devices — this is how BIOPAC describes the platform.
Linked Acquisition with the MP200 — a single AcqKnowledge session runs both the headset and the MP200 system with physiology modules.
TRIG BOX+ USB — markers from the stimulus presentation software reach the recording with a typical latency of 1.3 ms (1.2–1.5 ms), via a USB isolator.
Expansion — the Trigger Box can be extended for several synchronized systems, e.g. for hyperscanning.
From raw light to results
In the graph from BIOPAC materials: channels of one source over the motor cortex in a walking study with counting backward.
Filters, transformations and automated analysis in AcqKnowledge; Workflow Automation for repeatable procedures.
SPA-fNIRS — respiration, heart rate variability, EDA and movement from BIOPAC help separate the brain response from systemic changes.
Export to ACQ, MAT, EDF and SNIRF — further analysis in Homer3, NIRSTORM or SPM, among others.
Live data for other programs — Network Data Transfer (license) and the MedelOpt+ API (Windows) for neurofeedback and brain–computer interfaces.
What has changed: earlier versions of AcqKnowledge supported fNIR devices only by importing data recorded in a separate program. Since version 6.0.2, MedelOpt+ is controlled and recorded directly in AcqKnowledge. Seenel Imaging, the headset manufacturer, also provides its own acquisition program, ElOpt.
Sources: biopac.com — MedelOpt+ Infinity, AcqKnowledge: latest features (6.0.2), MedelOpt+ product sheet (11/2025); seenel-imaging.com — MedelOpt (MeMoSoft, API, compatibility with Homer 3, NIRSTORM, SPM). Screenshot and diagram: BIOPAC.
Why MedelOpt+ Infinity from Interlab
fNIRS, EEG and physiology as one system — not a set of plug-ins
fNIRS is sometimes sold as a module of a subscription platform, to which a device from another manufacturer is connected, with EEG and physiology added separately. MedelOpt+ is a different approach: both brain signals in one headset, recorded natively in AcqKnowledge together with the body.
MedelOpt+ Infinity from Interlab vs. a subscription platform with an fNIRS device from another manufacturer
Feature
MedelOpt+ Infinity from Interlab
Subscription platform + fNIRS from another manufacturer
fNIRS and EEG
in one headset — 8 EEG channels (512 Hz) integrated with the optodes
an fNIRS device which, according to the platform manufacturer, can be combined with a separate EEG
Connection to software
natively in AcqKnowledge — one interface controls the headset and the BIOPAC amplifiers
a data stream from the fNIRS manufacturer’s software, sent via Lab Streaming Layer
Physiology
MP200 and BioNomadix in the same recording — ECG, EDA, EMG, respiration and more
further platform modules, paid separately
Purchase model
hardware and software from one supplier, with implementation and training
mandatory core module and modules on a subscription with annual renewal
Subscription platform: a popular multimodal platform with an fNIRS module; description based on its manufacturer’s website (fNIRS module, pricing), as of 2026-10. MedelOpt+: biopac.com and BIOPAC product sheet (11/2025).
What you get from Interlab
An fNIRS lab up and running, and a trained team
We help plan the montage for your research question, install the system and teach you to work with the headset and AcqKnowledge.
Methodological consultingWe help you choose the model, channel density and separations for your question — before you buy anything.
Multimodal laboratoryMedelOpt+, BIOPAC and Tobii eye trackers from one supplier — configured together in AcqKnowledge.
Implementation and trainingWe set up the workstation and train your team in fitting the headset, montages and recordings.
Grant supportTechnical descriptions and configurations for grant applications and tender specifications.
Exclusive BIOPAC partner in PolandYou buy MedelOpt+, AcqKnowledge and BIOPAC hardware directly from us.
Local support in PolandTechnical and methodological support after purchase — no intermediaries.
Multimodal research · MedelOpt+ + BIOPAC + Tobii
Brain, body and gaze on one timeline
fNIRS and EEG show what is happening in the brain. BIOPAC adds how the body responds at the same moment — heart, skin, breathing, muscles. A Tobii eye tracker shows what the participant was looking at. AcqKnowledge records all of this in one file, and the stimulus marker is visible on every track.
A study from BIOPAC materials: treadmill walking (4 km/h) while counting backward in sevens — how the brain divides attention between movement and thinking.
Illustrative waveforms. Yellow lines — the moment a stimulus is shown, visible on every track.
In the Infinity headset
fNIRS: HbO and HbR from up to 32 detectors, 4/8/16/32 Hz.
EEG: 8 channels, 512 Hz, 24-bit.
Auxiliary inputs: 4 TTL channels, 512 Hz.
With the BIOPAC MP200 system
MP200: 16 analog channels up to 100 kHz per channel and 16 digital lines.
Data: biopac.com — MedelOpt+ Brain-Body Platform (fNIRS, EEG, physiology, stimulation, eye tracking and video in one interface), AcqKnowledge: latest features (Tobii eye tracker support, Windows, Eye Tracking license), MP200 data sheet; MedelOpt+ product sheet (11/2025). Photo: BIOPAC.
Specifications
Technical specifications
According to the product pages on biopac.com; details of the electronics, EEG and standards — from the BIOPAC product sheet (11/2025). Values common to the MedelOpt+ variants unless stated otherwise.
How does fNIRS differ from functional magnetic resonance imaging (fMRI)?
Both measure changes in blood flow and oxygenation associated with brain activity. fNIRS does this with light through the skin and skull, so it reaches the outer layers of the cortex rather than deep brain structures. In return, the participant sits at a desk, talks and even walks — the study takes place under ordinary conditions, not in a scanner.
How does Infinity differ from MedelOpt+ Mobility?
Infinity is the laboratory variant with the largest number of optodes: 16 sources and 16 or 32 detectors, for whole-head mapping. Mobility has 8 sources and up to 16 detectors and is wireless — for research on the move. Infinity can also work in mobile mode with the Mobility Pack (mini PC with battery). Comparison of variants: MedelOpt+ platform.
Can I start with 16-16 and expand the system later?
Yes — according to the manufacturer, sources and detectors can be added to the headset to increase the number of channels. We will confirm the scope of expansion for a specific configuration in the quote.
Is the headset suitable for studies with children?
Yes. The same adjustable headset fits heads from age 4 to adults. You don’t need to remove the headset to part the hair under the optodes — which shortens preparation.
Does hair interfere with the measurement?
Hair absorbs and scatters light, so in fNIRS the optode must touch the skin. The open design of MedelOpt+ lets you part the hair under each optode without removing the headset.
Do I need BIOPAC AcqKnowledge?
MedelOpt+ is fully integrated with AcqKnowledge (from version 6.0.2), and that is where you can most easily combine fNIRS and EEG with physiology, stimuli and eye tracking. The headset manufacturer, Seenel Imaging, also offers its own program, ElOpt, and for developers — the MedelOpt+ API. We will match the option to your laboratory.
What format will I get the data in?
AcqKnowledge saves and exports data to ACQ, MAT (MATLAB), EDF and SNIRF — the standard for fNIRS, which you can open in Homer3, NIRSTORM or SPM, among others. Live data can be streamed to other programs via Network Data Transfer.
Download materials
click to expand
Interested in this product?
Contact us for a detailed quote and technical advice.
