Chattanooga Primera TENS/NMES with HAN Waveform — 77615 / 77630

The Chattanooga Primera™ TENS/NMES is a dual-channel portable electrical stimulator combining 8 TENS programs and 6 NMES programs in one compact system.

Its distinguishing feature is not simply that it provides both modalities. Primera includes the HAN TENS waveform, which alternates between 2 Hz and 70 Hz rather than maintaining one continuous pulse frequency.

That makes Primera particularly relevant for buyers who want the following:

• TENS and NMES in one Chattanooga device
• A preset-driven operating system rather than extensive manual programming
• Dual-channel stimulation
• A replaceable 9V battery rather than a proprietary charger
• Continuous, burst, and Modulated TENS options
• The dedicated 2/70 Hz HAN TENS program
• Six NMES programs with different contraction-to-rest cycles
• A complete portable kit with lead wires, electrodes, carrying case and back-positioning belt

If you are still deciding whether your treatment objective calls for sensory-level TENS or contraction-producing NMES, read our TENS vs. NMES guide rather than treating the two modalities as interchangeable.

Primera contains both, which is the principal reason to choose it over a dedicated TENS-only or NMES-only device.

A comparison based only on the phrase “TENS/NMES unit” misses Primera's most important characteristics.

1. Eight distinctly programmed TENS options

Primera does not simply provide one TENS setting with adjustable intensity. Its TENS side includes the following:

• Three Continuous programs
• Two Burst programs
• Two Modulation programs
• One HAN program

Each program changes frequency, pulse width, duration, or stimulation pattern.

For a broader explanation of what continuous, burst, and modulation mean electrically, see our TENS Modes Explained.

2. Six NMES work/rest programs

The NMES programs use different combinations of:

• 12 or 35 Hz pulse rate
• 200 or 250 μs pulse width
• Contraction periods
• Recovery periods

That matters because an NMES program is not defined by intensity alone. The relationship between contraction time and recovery time affects how frequently the muscle is stimulated and how much recovery occurs between contractions.

3. A dedicated HAN waveform

The HAN program is more specific than the generic phrase “modulated TENS.”

It repeatedly alternates:

2 Hz / 250 μs for approximately 3 seconds

with

70 Hz / 150 μs for approximately 3 seconds

and runs as a 30-minute preset program.

These are programmed electrical parameters, not a diagnosis-to-program prescription. The appropriate program and electrode placement should follow the product instructions and any healthcare-professional guidance applicable to the user.

• Pulse frequency • Pulse width • Continuous vs. rst delivery • Automatically modulated parameters
• burst delivery
• Automatically modulated parameters
• Treatment duration

The six NMES presets all run for 15 minutes, but their pulse rate, pulse width, and work/rest ratios differ.

What changes between the NMES programs?

Notice that the later programs generally provide progressively longer recovery periods relative to the contraction period.

For example:

• P08 uses a 5-second contraction / 5-second rest
• P10 changes that to 5 / 10
• P12 changes it to 5 / 15

Similarly:

• P09 uses 8 / 8
• P11 uses 6 / 12
• P13 uses 6 / 18

That makes Primera's six NMES programs more meaningfully different than six different names for essentially identical stimulation.

The appropriate program is still determined by the treatment objective and product instructions. For broader NMES programming education, browse our NMES units and muscle stimulators and associated clinical guides.

HAN TENS is an alternating-frequency TENS pattern built into Primera.

Unlike continuous TENS, which maintains one selected pulse pattern, Primera's HAN program automatically alternates between a low-frequency and higher-frequency phase.

The program alternates between 2 Hz and 70 Hz every few seconds.

This makes Primera different from basic TENS/NMES combination devices, which only offer continuous or modulated TENS and do not have this alternating-frequency program.

Which Primera model should I choose?

Choose the model that matches the purchasing channel, device labeling, and healthcare-provider requirements associated with your intended use.

Primera is specified as a constant-current stimulator with an indicated output range of 0–80 mA, but the maximum available current depends partly on the electrical resistance of the electrode/skin circuit.

The manual provides additional detail:

This information is useful when comparing electrotherapy devices because “80 mA” is not the same thing as saying every user receives 80 mA under every electrode condition.

Electrode size, hydrogel condition, placement, and skin/electrode impedance all influence the stimulation circuit.

For replacement pads, compare Balego TENS/NMES/FES electrodes or Chattanooga DURA-STICK PLUS electrodes.

Primera has two individually isolated output channels.

A typical complete electrical channel uses a pair of electrodes:

The two channels have separate intensity controls, allowing the stimulation level to be balanced when both electrode pairs are used.

That is useful for broader treatment areas, bilateral placements, or applications where two separate electrode circuits are appropriate.

Always use the configuration and placement permitted by the manual and treatment plan.

Primera incorporates a feature that is easy to mistake for a malfunction if the user does not know about it.

Approximately 45 seconds after you turn on the unit, the intensity controls lock.

If you return to the device and the mA level does not immediately increase, the unit may simply be in its normal intensity-lock state rather than being defective.

The manufacturer instructs the user to activate the channel's decrease control before making a subsequent intensity adjustment.

This lockout helps reduce accidental changes after treatment has begun.

Primera also monitors the electrode circuit.

If an open circuit is detected on Channel A or Channel B, the affected output is reset to zero.

An unexpected drop to zero can, therefore, indicate the following:

• A pad has lifted from the skin
• An electrode has dried out
• A lead is loose
• A lead wire is damaged
• A connector is not fuThe lead wire is not fully seated.

The back belt is particularly noteworthy because it is not a standard accessory with every portable TENS/NMES machine.

The best alternative depends on which feature you actually need.

Choose Primera when:

• You specifically want a Chattanooga TENS/NMES unit.
• The HAN 2/70 Hz TENS program is important.
• Fourteen manufacturer-set programs provide sufficient programming flexibility.
• A replaceable 9V battery is preferable to rechargeable power.
• The included electrode-positioning back belt is useful.
• You do not need IFC or Russian stimulation.
• You do not need the Continuum's switch-triggered functional-stimulation capabilities.

Choose the Twin Stim IV instead when your priority is a rechargeable TENS/NMES device with a larger library of body-area presets.

The priority is a rechargeable TENS/NMES device with a larger library of body-area presets.

The Twin Stim IV provides 18 TENS and 18 NMES programs, a rechargeable lithium battery, and presets for areas including the neck, shoulder, hand, low back, knee, and foot.

Choose the Select Combo II instead when:

Your treatment equipment needs to extend beyond TENS and NMES.

The InTENSity Select Combo II adds interferential current and Russian stimulation, so it is a more versatile multimodality option.

Choose the Chattanooga Continuum instead when:

Functional rehabilitation and independent control of the two channels matter more than Primera's HAN waveform.

The Chattanooga Continuum can operate different programs on its two channels, includes a hand switch, and supports an optional heel switch for selected clinician-directed gait applications.

Choose a dedicated NMES unit instead when:

You do not need TENS.

The Balego EMS Digital NMES Stimulator provides manual control over NMES parameters without requiring the buyer to pay for additional TENS programs.

Primera may be more equipment than you need if the treatment plan requires only TENS.

The condition of the electrode can significantly impact both comfort and the quality of stimulation.

Replace a reusable pad when it no longer adheres over its full surface:

• No longer adheres over its full surface
• Develops curled edges
• Has dried hydrogel
• Produces an unusually sharp or concentrated sensation
• Has damaged backing or connector components
• Cannot maintain a dependable electrical circuit

For Chattanooga replacement pads, compare DURA-STICK PLUS TENS/NMES electrodes.

For a lower-cost American-made replacement option, compare Balego TENS/NMES/FES electrodes, available in several common sizes and shapes.

Do not select replacement electrodes by appearance alone. Confirm that the electrode connector, lead wire, and device instructions are compatible.

Primera not working? Read the Primera troubleshooting and user guide.

How many programs does the Chattanooga Primera have?

Primera has 14 preset programs: 8 TENS and 6 NMES.

The TENS programs include continuous, burst, modulation, and HAN patterns. The NMES programs use different combinations of 12 or 35 Hz stimulation and varying work/rest cycles.

What is the HAN waveform on Primera?

Primera's HAN program alternates between 2 Hz at a 250 μs pulse width and 70 Hz at a 150 μs pulse width, switching approximately every three seconds during a 30-minute program.

Is Primera both TENS and NMES?

Yes. It contains separate TENS and NMES preset programs.

For a complete explanation of how the two modalities differ, see our TENS vs. NMES guide.

Does Primera have two channels?

Yes. Primera has two individually isolated channels with separate intensity controls.

Can Primera use four electrodes?

Two complete active channels normally allow a four-electrode setup when that configuration and placement are appropriate for the treatment.

How strong is Primera?

The indicated output range is 0–80 mA. The manual notes that maximum available current decreases as circuit resistance increases, with documented maximums of approximately 80 mA at 500 Ω, 70 mA at 1,000 Ω, and 65 mA at 1,500 Ω.

Why is the intensity of my Primera not increasing?

Primera has an intensity lockout that activates approximately 45 seconds after the device is powered on. The manual instructs the user to press the decrease control before making another intensity adjustment.

Also ensure that the electrodes and lead wires remain securely connected because an open circuit causes the affected channel output to reset to zero.

Is Primera rechargeable?

No. Primera uses a replaceable 9V alkaline battery.

If rechargeable power is a priority, compare the Twin Stim IV.

What is the difference between Primera and Twin Stim IV?

Both provide TENS and NMES through two channels.

Primera's distinctive features are its HAN 2/70 Hz waveform, Chattanooga platform, replaceable 9V power, and included back-positioning belt.

The Twin Stim IV instead emphasizes rechargeable power, 36 programs, and body-region presets.

What is the difference between Primera and Chattanooga Continuum?

Primera is the simpler preset-oriented Chattanooga TENS/NMES system and includes the HAN waveform.

The Chattanooga Continuum is more oriented toward clinician-programmed functional rehabilitation, with independently controlled channels, an included hand switch, and an optional heel switch.

Does Primera provide IFC?

No.

If interferential current is required, compare the InTENSity Select Combo II, which provides TENS, NMES, IFC, and Russian stimulation.

Does Primera provide Russian stimulation?

No. Primera provides TENS and NMES.

What is the difference between Primera 77615 and 77630?

77615 is the professional/prescription Primera kit.

77630 is the manufacturer's over-the-counter Primera model.

What is the GTIN for Primera 77615?

The FDA AccessGUDID primary device identifier for model 77615 is 00888912373852.

What is the GTIN for Primera 77630?

The FDA AccessGUDID primary device identifier for model 77630 is 00190446136897.

What electrodes can I buy for Primera?

Use electrodes compatible with the Primera lead-wire system and manufacturer instructions. Balego carries Chattanooga DURA-STICK PLUS electrodes as well as Balego TENS/NMES/FES electrodes.

Primera is most compelling when the purchasing checklist looks like this:

Need TENS? Yes. Need NMES? Yes. Need two channels? Yes. Want Chattanooga? Yes. Prefer predetermined programs? Yes. Interested in HAN 2/70 Hz stimulation? Yes. Prefer a replaceable battery? Yes. Need IFC or Russian? No. Need functional hand/heel switch triggering? No.

Primera occupies a useful position between a basic TENS/NMES combination unit and the more sophisticated Chattanooga Continuum.

Browse related TENS devices, NMES and EMS stimulators, and electrotherapy electrodes to compare the complete setup.

Use the Primera only according to the current product labeling, user manual, and applicable healthcare professional instructions.

Electrical stimulation is not appropriate for every person or every body location. The Primera manual lists specific contraindications, warnings, and electrode-placement restrictions, including precautions for implanted electronic devices, pregnancy, impaired sensation, and certain cardiovascular or neurological conditions.

Do not place electrodes in a location prohibited by the manufacturer's instructions. Turn stimulation off before repositioning pads. Stop use if stimulation produces burning, significant skin irritation, unexpected symptoms, or painful muscle activity.

This product information is intended to help compare equipment and does not establish an individual treatment protocol.