SMD Components, Neurostimulators, ECG, and Hearing Technology

 SMD Components, Neurostimulators, ECG,

and Hearing Technology

Project Questions and Answers in Chronological Order - US English Edition

Authors: Richard Svanberg and ChatGPT

Date: September 24, 2026

Question 1 - Richard Svanberg

Are there ECG systems with neurotransmitter functionality?

Answer 1 - ChatGPT

Yes, but not as a standard clinical ECG. An ECG measures the heart's electrical

activity using electrodes on the skin and does not directly measure

neurotransmitters.

However, there are research systems that combine electrical recording with

electrochemical measurement of neurotransmitters. For example, nanoelectrode

arrays have been demonstrated that can record neuronal electrical activity and

dopamine release at the same time. There are also sensors capable of measuring

several neurotransmitters, such as dopamine, serotonin, acetylcholine, and

glutamate.

In principle, a system can therefore be built with two separate measurement

channels:

ECG electrodes -> analog amplifier/ADC -> MCU

neurotransmitter sensor -> potentiostat/ADC -> MCU

The two signal streams can then be collected by the same electronics. Implantable,

wireless, and battery-free systems for electrochemical measurement of

catecholamines have also been demonstrated experimentally.

If by "neurotransmitter functionality" you instead mean that the device stimulates

the nervous system or affects neurotransmitter release, rather than measuring

neurotransmitters, that is a different type of system - more similar to a

neurostimulator plus a biosensor than to an ECG.

Sources cited in the original answer:

https://doi.org/10.1002/smsc.70249

https://link.springer.com/article/10.1186/s40486-024-00211-3

https://pubs.acs.org/doi/full/10.1021/acsnano.2c09475

Question 2 - Richard Svanberg

Richard Svanberg & ChatGPT - September 24, 2026 Page 1Can such a device, with electrodes placed on the body, affect a pacemaker?

Answer 2 - ChatGPT

Yes. Electrodes placed on the body can affect a pacemaker if they are used to send

electrical impulses through the body, for example with TENS, EMS, or nerve/muscle

stimulation. In some situations, the pacemaker can misinterpret external electrical

signals as cardiac activity, which can cause temporary interference or inhibition of

pacing. The FDA has also reported interference between electrical muscle

stimulators and pacemakers/implanted defibrillators.

It is important to distinguish between ECG electrodes used only for measurement

and stimulating electrodes. A standard diagnostic ECG does not normally deliver

stimulating current through the body, and the American Heart Association considers

ECG a procedure with low risk of pacemaker interference. TENS/NMES, however,

requires caution, especially if the electrodes are placed on the chest or if the current

path passes close to the pacemaker or its leads.

If you are considering a system that both measures ECG and includes a

neurotransmitter/neurostimulation function, the stimulation part is therefore the

most relevant part in relation to the pacemaker. Such a combination should not be

tested on a person with a pacemaker unless the pacemaker model, electrode

placement, current level, pulse waveform, and frequency have been assessed by a

pacemaker clinic or cardiologist.

Sources cited in the original answer:

https://www.fda.gov/medical-devices/consumer-products/electronic-muscle-stimulat

ors

https://www.heart.org/en/health-topics/arrhythmia/prevention--treatment-of-arrhyth

mia/devices-that-may-interfere-with-icds-and-pacemakers

https://www.accessdata.fda.gov/cdrh_docs/pdf15/p150012d.pdf

Question 3 - Richard Svanberg

Does it work the same way with SMD components with similar functions located in

the head? Do they have the same functions as a pacemaker?

Answer 3 - ChatGPT

Partly, but not in the same way as a pacemaker.

A pacemaker has a very specific function: it monitors the heart's electrical activity

and can deliver electrical pulses to the heart when needed. Some medical implants

in the head or neck can also use electrodes and electrical pulses, for example deep

brain stimulation (DBS), cochlear implants, or certain nerve stimulators. They can

therefore share basic principles - sensors, electrodes, electronics, and stimulation -

but they interact with different tissues and use different signals.

Richard Svanberg & ChatGPT - September 24, 2026 Page 2An individual SMD component, however, is simply a small electronic component,

such as a resistor, chip, capacitor, or transistor. You cannot determine that it

functions as a pacemaker or neurostimulator simply because it is small or located

near the head. A functioning implant normally requires a complete system: power

supply, control circuitry, electrodes, enclosure, and often communication or

programming capability.

If a medical implant is actually present in the head, it is important to identify the

model and manufacturer through medical records, an implant card, or medical

imaging, because pacemaker interaction and safety depend on the exact type of

implant involved.

Question 4 - Richard Svanberg

What are the SMD components in the head called if the device is called a pacemaker

when it is located near the heart?

Answer 4 - ChatGPT

If a comparable type of implant is located in or near the head, it is usually called a

neurostimulator, not a pacemaker.

Common names include a DBS system (Deep Brain Stimulation) when electrodes

stimulate the brain, a neurostimulator or implantable pulse generator (IPG) when a

pulse generator drives electrodes, and a cochlear implant when the system

stimulates the auditory nerve. There is also RNS (Responsive Neurostimulation),

which can both record brain activity and provide stimulation.

The small electronic parts inside these systems are still called SMD components - for

example ICs, resistors, capacitors, and transistors. It is the function of the complete

implant system that determines whether it is called a neurostimulator, DBS, RNS,

and so on; the individual electronic components do not receive a special name

simply because they are used in the head.

Question 5 - Richard Svanberg

What are devices called that use CMOS speakers and CMOS microphones placed in

the ears and transmit electronic signals that become sound in the ear?

Answer 5 - ChatGPT

What you are describing is not usually referred to as one specific component type. If

the device is located in or near the ear and uses a microphone plus a very small

speaker to convert electronic signals into sound, common terms are hearing aid,

hearable, in-ear audio device, or, if it is a medical device, hearing implant.

If the system is implanted and electrically stimulates the auditory pathway, more

specific terms include cochlear implant or auditory brainstem implant. If the sound

Richard Svanberg & ChatGPT - September 24, 2026 Page 3is instead produced by a physical miniature speaker in the ear canal, the system is

more similar to a hearing-aid/hearable system than to a neurostimulator.

One small correction: the terms MEMS microphone and MEMS microspeaker are

usually more accurate than "CMOS microphone/speaker." CMOS can be part of the

electronics, particularly the microphone ASIC, but the acoustic transducer itself is

normally described as MEMS.

The distinction can therefore be summarized as MEMS microphone + MEMS

speaker, cochlear implant, or auditory brainstem implant depending on how the

signal is converted and delivered to the auditory system.

Question 6 - Richard Svanberg

Is a neurostimulator made of SMD components, or can it be?

Answer 6 - ChatGPT

Yes, a neurostimulator can contain many SMD components, but the neurostimulator

itself is not a single SMD component.

Typical electronics can include SMD resistors, capacitors, transistors, diodes,

op-amps, ADC/DAC devices, a microcontroller or ASIC, memory, voltage regulators,

and RF circuits. These components are mounted on a small circuit board or

substrate and work together with electrodes, a power supply, and an enclosure.

A simple way to think about it is:

Neurostimulator = complete medical electronic system

SMD components = the electronic building blocks inside the system

In very small implants, nearly all of the electronics can be implemented using SMD

components or integrated directly into specialized chips.

Richard Svanberg & ChatGPT - September 24, 2026 Page 4