I am currently exploring whether physiological information could become more than a hidden sensor input and instead be turned into a physical, understandable cue that helps the person notice what is happening in their own body.

This paper stood out because it does exactly that. Rather than translating heartbeat data into a graph or number, it converts each detected heartbeat into a tactile sensation on the chest.

My notes focused on the idea of heartbeat supplementation: combining biofeedback with sensory augmentation so that the person feels an amplified version of their own cardiac rhythm.

That is different from many of the systems I have looked at so far. The response is not trying to slow the body, distract from stress or deliver a generic calming pattern. It is trying to make an existing internal signal easier to perceive.

What the technology is

The researchers developed a real-time haptic heartbeat-feedback system.

A Plux ECG sensor records the participant’s heartbeat. A custom Python system detects each ECG R-peak in real time, and every detected beat triggers a vibration through a Woojer haptic speaker positioned on the front-middle of the chest, above the heart area.

The vibration is designed to mimic the sensation of the participant’s own heartbeat rather than feeling like an arbitrary notification.

The researchers shaped the haptic pulse to resemble the pressure rise associated with systole. Each vibration begins when the heartbeat is detected, peaks around 200 ms later and ends around 400 ms after detection.

This is why the term sensory augmentation makes sense here: the system is not inventing a new rhythm. It is amplifying and externally reinforcing a bodily rhythm that is already happening.

Why the chest placement matters

One of my notes was that the Woojer vibration speaker sat over the anterior middle section of the chest.

That placement is important because the feedback is deliberately aligned with where a heartbeat might naturally be felt.

The researchers argue that haptic feedback may be easier to integrate with internal bodily sensation when it matches the natural signal in timing, location and physical quality.

This is a useful contrast with wrist-based haptics. A wrist vibration can communicate information about heart rate, but a chest vibration that arrives exactly with the heartbeat may feel more like a direct extension of the bodily sensation itself.

For my project, that raises an interesting material and placement question: should feedback simply be understandable, or should its physical location also relate to the body signal it represents?

What the researchers tested

The study involved 60 healthy adults, randomly divided into two groups of 30.

Both groups completed a 12-minute heartbeat-perception training session.

The haptic group received real-time vibration on the chest, synchronised to each heartbeat.

The comparison group received real-time visual heartbeat feedback instead. They watched an image of a heart on a screen that expanded and contracted in time with their actual heartbeat.

Before and after the training, participants completed a heart-rate discrimination task that tested how accurately they could judge their own cardiac rhythm. The researchers also measured confidence, attention toward bodily sensations and state anxiety.

The haptic feedback faded out

I found the training structure particularly interesting.

The vibration did not remain equally strong throughout each training run. Participants first selected a comfortable vibration intensity and a minimum level that they could still detect.

Across each run, the vibration then gradually faded from the comfortable intensity towards zero.

The participant was asked to keep attending to the heartbeat as the external cue became weaker.

This means the technology was being used almost like temporary scaffolding: first making the bodily signal obvious, then reducing the assistance so the participant increasingly relies on their own internal perception.

That is a very different interaction model from continuous wearable support.

It raises a useful question for my project about whether responsive technology always needs to remain active, or whether some responses could help the traveller re-orient and then deliberately fade into the background.

What the results showed

After a single 12-minute session, the haptic group showed improved interoceptive accuracy and increased confidence in judging their heart rate.

Their attention also shifted more towards bodily sensations.

The visual-feedback group did not show the same improvements on those measures.

Participants also rated the haptic training as more pleasant and more helpful than the visual version.

This suggests that the sensory form of biofeedback matters. Presenting the same physiological information through touch can create a different experience from representing it visually.

For my project, that is important because it challenges the assumption that biodata needs to become a dashboard, graph or visual alert in order to be useful.

This was not evidence of a stronger calming effect

I need to separate the interoception result from the anxiety result.

State anxiety decreased after both the haptic and visual training.

There was no significant difference between the groups in how anxiety changed.

The authors themselves describe this anxiety reduction as non-specific and suggest that factors such as habituation, fatigue or boredom may have contributed.

So although the haptic system improved heartbeat perception, this study does not demonstrate that haptic heartbeat feedback was better than visual feedback for reducing anxiety.

That distinction matters for my project.

The evidence supports interoceptive training and bodily awareness, not a claim that feeling your heartbeat through vibration is necessarily a calming intervention.

Why this changes how I think about biofeedback

Until now, I have often been thinking about biosensing as:

the system detects a physiological change → the system decides whether support may be useful

This paper introduces another possibility:

the system detects a bodily signal → the system makes that signal more perceptible to the person

That shifts some interpretation back to the user.

Instead of the device saying “you are stressed”, it could potentially help the person notice a change in their own bodily rhythm and decide what it means for them.

That feels much more compatible with my project position that physiological data should be treated as information rather than diagnosis.

What could biodata actually control?

In this system, live ECG controls the exact timing of the haptic pulse.

Each real heartbeat produces a corresponding vibration.

The system also allows the vibration amplitude to be adjusted for comfort, and the training protocol gradually reduces that amplitude.

So the most direct biodata-controlled characteristic is:

timing / rhythm of the tactile feedback.

A future wearable could theoretically also use physiological information to decide when heartbeat supplementation becomes available or how long it continues, but this paper does not test that.

The strongest evidence here is much simpler: real-time physiological timing can directly drive a tactile sensation that mirrors the body's own rhythm.

A very different relationship to automation

I find this especially useful because the system is responsive without trying to infer a hidden emotional state.

It does not need an algorithm to decide whether a heartbeat means anxiety, sensory overload, excitement or physical exertion.

It simply mirrors the heartbeat.

That removes one layer of uncertainty from the response logic.

However, it does not remove the design problem entirely. The traveller still needs to decide whether increased awareness of their heartbeat is useful or comfortable in that moment.

For some people, especially during anxiety, stronger awareness of cardiac sensations could potentially be unpleasant rather than grounding.

That possibility was not tested in an autistic airport context.

Interoception and autism

This study itself involved healthy adults, not autistic participants.

The authors do reference earlier research showing that interoceptive training has been explored with autistic adults, including work targeting anxiety.

But I need to keep that separate from the current experiment.

This paper demonstrates that real-time haptic heartbeat supplementation can improve cardioceptive accuracy in a general adult sample.

It does not demonstrate that chest-based heartbeat haptics would improve regulation, orientation or airport accessibility for autistic adults.

For my project, the connection is therefore a design inference.

If some autistic travellers find awareness of bodily changes useful for recognising when support may be needed, a tactile representation could be worth exploring. But that needs to be tested rather than assumed.

Sensory comfort is central

The researchers individually adjusted the vibration so that it was clearly perceptible but comfortable and not disturbing.

That detail is easy to overlook, but I think it is very important.

Even in a controlled healthy-adult sample, the researchers did not assume one vibration amplitude would suit everyone.

For an autism-focused system, I would need to go further.

The user should be able to decide:

whether heartbeat feedback is wanted at all; where it is felt; its maximum intensity; whether it fades; how long it lasts; and how it stops immediately.

The chest location may also be unacceptable for some users because of clothing, body sensitivity, pressure, visibility or the intimacy of that placement.

Airport relevance

There is something appealing about biofeedback that does not require the traveller to look at a screen.

A tactile heartbeat cue could potentially preserve visual and auditory attention for navigation, signage, announcements and interaction with staff.

The authors also describe the haptic method as relatively low-demand because it attracts attention towards the body without requiring continuous visual monitoring.

However, the study was conducted seated in a quiet room, with ECG electrodes, a computer and a chest-mounted Woojer device.

That is very different from walking through an airport.

Movement could affect sensing quality, the physical setup is currently too cumbersome for travel, and awareness of the heartbeat might be distracting at exactly the wrong moment.

The mechanism may be relevant, but the implementation would need substantial redesign.

The comparison with visual feedback is useful

One of the strongest things I take from this paper is that the same biodata can feel different depending on how it is represented.

The visual group saw a heart animation synchronised with their heartbeat.

The haptic group physically felt a heartbeat-like pulse on the chest.

Only the haptic group showed the clear improvements in cardioceptive accuracy, confidence and bodily attention, and they rated the experience more positively.

The researchers interpret this partly through the sensory match between the artificial cue and the natural bodily sensation.

For my project, this reinforces that feedback modality cannot be chosen purely for convenience.

If I want the response to feel intuitive, I need to ask:

what physical form best matches the information I am trying to communicate?

Limitations

This was a single-session laboratory study.

Only immediate before-and-after effects were measured, so the study does not show whether the improvements persist over time.

The main outcome focused on cardiac interoception, so the results should not be generalised to interoception as a whole.

The participants were healthy adults rather than a clinical or autistic sample.

The setup also relied on ECG electrodes, a computer, custom software and a chest-mounted vibration speaker, which is far from a finished portable wearable.

Most importantly for my project, the study did not test whether increased heartbeat awareness is beneficial during real-world sensory stress, movement or airport travel.

What this means for my project

This paper opens a different direction within biofeedback.

Instead of using physiology only to trigger an intervention, I could explore whether the body's own signal can become the feedback.

That creates a more transparent relationship:

heartbeat detected → heartbeat physically represented → traveller notices bodily change → traveller decides what support they want

rather than:

heartbeat detected → system infers stress → system automatically intervenes.

I find that attractive because it keeps the person's interpretation inside the loop.

At the same time, I do not yet know whether stronger interoceptive awareness would feel grounding, distracting or anxiety-provoking for the people I am designing with.

So I am keeping this paper as a strong precedent for real-time haptic biofeedback, heartbeat supplementation and sensory augmentation, not as evidence that heartbeat feedback is an airport regulation intervention.

The design question it leaves me with is:

could biodata be made tangible enough to support self-awareness without making the traveller monitor themselves more?

Source

Dobrushina, O., Tamim, Y., Wald, I. Y., Maimon, A. and Amedi, A. (2024). Interoceptive training with real-time haptic versus visual heartbeat feedback. Psychophysiology, 61(11), e14648.

Key reading from my notes and analysis: heartbeat-supplementation concept, pp. 1–2; Woojer chest placement and real-time ECG-driven haptic design, pp. 3–4; heartbeat-discrimination task and study design, pp. 4–5; interoception, attention and user-experience findings, pp. 6–8; interpretation, limitations and future applications, pp. 8–10.