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possibly-humanpossibly-human
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EDA (#53)
* Initial commit Real-time EDA decomposition and SCR detection. * Changed object name
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‎CMakeLists.txt‎

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@@ -116,6 +116,16 @@ avnd_score_plugin_add(
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NAMESPACE puara_gestures::objects
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)
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avnd_score_plugin_add(
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BASE_TARGET score_addon_puara
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SOURCES
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Puara/EdaRtFeatures.hpp
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Puara/EdaRtFeatures.cpp
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TARGET puara_eda
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MAIN_CLASS EdaRtFeatures
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NAMESPACE puara_gestures::objects
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)
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avnd_score_plugin_add(
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BASE_TARGET score_addon_puara
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SOURCES

‎Puara/EdaRtFeatures.cpp‎

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#include "EdaRtFeatures.hpp"
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namespace puara_gestures::objects
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{
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float EdaRtFeatures::onepole_lp(float y, float x, double dt, float fc)
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{
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if(fc <= 0.0f || dt <= 0.0) return x;
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const double a = std::exp(-2.0 * M_PI * static_cast<double>(fc) * dt);
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return static_cast<float>(a * y + (1.0 - a) * x);
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}
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void EdaRtFeatures::prepare(halp::setup info)
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{
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setup = info;
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_have_input = false;
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_last_x = -1e9f;
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_time = 0.0;
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_scl = 0.0f;
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_baseline = 0.0f;
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_state = State::Idle;
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_onset_base = 0.0f;
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_onset_time = 0.0;
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_peak_val = 0.0f;
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_peak_time = 0.0;
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_confirm_acc = 0.0;
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_last_peak_t = -1e9;
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_rec_target = 0.0f;
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for(int i=0; i<VALLEY_WIN; ++i){ _val_p[i]=0.0f; _val_t[i]=0.0; }
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_val_i = 0;
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_h_amp = 0.0f;
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_h_rise = 0.0f;
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_h_dur = 0.0f;
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outputs.scl = 0.0f;
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outputs.scr = 0.0f;
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outputs.scr_event = 0;
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outputs.scr_amplitude_us = 0.0f;
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outputs.scr_rise_time_s = 0.0f;
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outputs.scr_duration_s = 0.0f;
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}
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void EdaRtFeatures::operator()(halp::tick t)
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{
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const double dt = (setup.rate > 0.0)
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? ((t.frames > 0) ? static_cast<double>(t.frames) / setup.rate : 1.0 / setup.rate)
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: 1.0 / 50.0;
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outputs.scr_event = 0;
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if(inputs.reset) { prepare(setup); return; }
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const float x = inputs.signal;
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// ── startup: wait for first nonzero sample ────────────────────────────────
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if(!_have_input)
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{
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if(x == 0.0f) { return; }
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_have_input = true;
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_scl = x;
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_baseline = 0.0f;
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_time = 0.0;
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}
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// ── always write held outputs────────────
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outputs.scr_amplitude_us = _h_amp;
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outputs.scr_rise_time_s = _h_rise;
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outputs.scr_duration_s = _h_dur;
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// ── per new sample: update tonic, phasic, valley buffer, baseline ──────────
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const bool new_sample = (x != _last_x);
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if(new_sample)
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{
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_last_x = x;
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_time += dt;
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_scl = onepole_lp(_scl, x, dt, 0.05f);
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}
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const float phasic = x - _scl;
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outputs.scl = _scl;
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outputs.scr = phasic;
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if(new_sample)
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{
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// push to valley ring buffer
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_val_p[_val_i % VALLEY_WIN] = phasic;
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_val_t[_val_i % VALLEY_WIN] = _time;
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++_val_i;
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// slow baseline EMA
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const float ba = static_cast<float>(1.0 - std::exp(-dt / 10.0));
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_baseline += (phasic - _baseline) * ba;
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}
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// ── detection thresholds ──────────────────────────────────────────────────
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static constexpr float MIN_AMP = 0.04f; // µS
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static constexpr float ONSET_TH = 0.05f; // above baseline to start rising
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static constexpr float DROP_TH = 0.012f; // fall below peak to accumulate confirm
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static constexpr double CONFIRM_S = 0.30; // seconds of falling to confirm peak
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static constexpr double MIN_DIST = 1.0; // refractory seconds
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static constexpr double MAX_REC = 10.0; // max recovery seconds
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if(!new_sample) return;
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// re-arm when phasic settles near baseline
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if(phasic <= _baseline + 0.3f * ONSET_TH)
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_rearmed = true;
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// ── always emit held values ───────────────────────────────────────────────
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outputs.scr_amplitude_us = _h_amp;
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outputs.scr_rise_time_s = _h_rise;
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outputs.scr_duration_s = _h_dur;
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// ── state machine ─────────────────────────────────────────────────────────
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switch(_state)
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{
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case State::Idle:
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{
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const bool refract_ok = (_time - _last_peak_t >= MIN_DIST);
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if(_rearmed && refract_ok && (phasic - _baseline) >= ONSET_TH)
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{
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_rearmed = false;
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_state = State::Rising;
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// onset = valley (minimum phasic) in lookback window
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_onset_base = phasic; _onset_time = _time;
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for(int i=0; i<VALLEY_WIN; ++i)
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if(_val_p[i] < _onset_base){ _onset_base=_val_p[i]; _onset_time=_val_t[i]; }
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_peak_val = phasic;
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_peak_time = _time;
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_confirm_acc = 0.0;
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}
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break;
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}
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case State::Rising:
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{
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if(phasic > _peak_val)
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{
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_peak_val = phasic;
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_peak_time = _time;
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_confirm_acc = 0.0;
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}
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else if(phasic <= _peak_val - DROP_TH)
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{
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_confirm_acc += dt;
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}
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else
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{
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_confirm_acc = 0.0;
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}
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if(_confirm_acc >= CONFIRM_S)
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{
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// peak confirmed
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const float amp = _peak_val - _onset_base;
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const double rise_t = _peak_time - _onset_time;
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if(amp >= MIN_AMP)
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{
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_h_amp = amp;
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_h_rise = std::min(static_cast<float>(rise_t), 3.0f);
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outputs.scr_event = 1;
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outputs.scr_amplitude_us = _h_amp;
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outputs.scr_rise_time_s = _h_rise;
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_last_peak_t = _peak_time;
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_rec_target = _onset_base + amp * 0.5f; // 50% recovery
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_state = State::Recovering;
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}
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else
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{
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_state = State::Idle;
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}
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}
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break;
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}
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case State::Recovering:
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{
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if(phasic <= _rec_target || _time - _peak_time > MAX_REC)
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{
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_h_dur = static_cast<float>(_time - _onset_time);
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outputs.scr_duration_s = _h_dur;
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_state = State::Idle;
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}
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break;
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}
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}
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}
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} // namespace puara_gestures::objects

‎Puara/EdaRtFeatures.hpp‎

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#pragma once
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#include "halp_utils.hpp"
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#include <halp/controls.hpp>
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#include <halp/meta.hpp>
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#include <algorithm>
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#include <cmath>
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namespace puara_gestures::objects
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{
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class EdaRtFeatures
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{
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public:
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halp_meta(name, "EDA")
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halp_meta(category, "Analysis/Biodata")
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halp_meta(c_name, "puara_eda_rt")
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halp_meta(author, "Luana Belinsky")
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halp_meta(description, "Real-time EDA decomposition and SCR detection.")
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halp_meta(uuid, "f0f6b04e-0e11-4acf-96bd-bf54b78078ca")
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struct
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{
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halp::data_port<"EDA", "Input EDA in µS.", float> signal;
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halp::toggle<"Reset"> reset;
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} inputs;
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struct
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{
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halp::data_port<"SCL", "Tonic.", float> scl;
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halp::data_port<"SCR", "Phasic.", float> scr;
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halp::data_port<"SCR event", "1 for one tick at SCR peak.", int> scr_event;
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halp::data_port<"SCR amplitude", "Peak amplitude µS.", float> scr_amplitude_us;
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halp::data_port<"SCR rise time", "Rise time s.", float> scr_rise_time_s;
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halp::data_port<"SCR duration", "Duration s.", float> scr_duration_s;
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} outputs;
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halp::setup setup;
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void prepare(halp::setup info);
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using tick = halp::tick;
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void operator()(halp::tick t);
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private:
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static float onepole_lp(float y, float x, double dt, float fc);
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enum class State { Idle = 0, Rising = 1, Recovering = 2 };
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bool _have_input = false;
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float _last_x = -1e9f;
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double _time = 0.0;
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float _scl = 0.0f;
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float _baseline = 0.0f;
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bool _rearmed = true;
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State _state = State::Idle;
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float _onset_base = 0.0f;
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double _onset_time = 0.0;
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float _peak_val = 0.0f;
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double _peak_time = 0.0;
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double _confirm_acc = 0.0;
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double _last_peak_t = -1e9;
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float _rec_target = 0.0f;
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// ring buffer: phasic + time, 0.75s lookback for valley detection
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static constexpr int VALLEY_WIN = 38; // 0.75s at 50 Hz equivalent
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float _val_p[VALLEY_WIN]{};
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double _val_t[VALLEY_WIN]{};
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int _val_i = 0;
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float _h_amp = 0.0f;
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float _h_rise = 0.0f;
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float _h_dur = 0.0f;
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};
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} // namespace puara_gestures::objects

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