CarbSens
Metabolic Response Monitoring

Estimate metabolic changes without measuring glucose.
Carb value (carbohydrate response) × VeST value (vascular symmetry tracking).
Non-invasive monitoring using pulse waves from hands and feet.
Exploring insulin-related microvascular responses through PPG machine learning.

CGM lag comparison and complementary insights

Hydration trend monitoring

Observing vascular responses related to fluid loss in hot environments using PPG！

Start smart health monitoring with Polar Verity Sense and the CarbSens app.

Compatible with iPhone / iPad / Android.

Carb value (1 device)

CarbSens estimates carbohydrate-related metabolic changes from post-meal pulse wave variations. It provides hints for reviewing daily eating habits without measuring glucose. We are also researching early signs of postprandial hypoglycemia, CGM lag comparison, and autonomic nervous system patterns.

VeST value (2 devices)

By measuring pulse waves from both hands or feet simultaneously, CarbSens visualizes left–right vascular differences and peripheral circulation changes. These left–right patterns are known to show alterations in conditions such as cognitive decline and cerebrovascular disorders, reflecting autonomic nervous system balance and vascular flexibility. This may also support early awareness of changes related to diabetic foot care, cold sensitivity, or stress. Up to 4 devices (4 points) can be measured at once, or 2 devices × 2 sessions.

Move one step ahead in health monitoring with pulse waves and glucose trends

CarbSens provides a non-invasive estimate of carbohydrate impact and overall metabolic response (Carb value) using pulse wave data captured by the Polar Verity Sense.

■CarbSens Contents

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■ CarbSens Contents

• ■ Overview
• ■ Data Explanation (Japanese)
• ■ Post-meal Curve & Sleep Curve Analysis (Japanese)
• ■ Dual Measurement (2-point) & Stress Trend Check (Japanese)
• ■ Postprandial Hypoglycemia Prediction – Machine Learning
• ■ CarbSens–CGM Comparison & CGM Complementary Analysis
• ■ Autonomic Function Evaluation – HR/SV & VeST Methods
• 🚗 Driver Monitor – Driving & Train Ride Data
• 🛍️ App Intent Integration Specification (Japanese)

Dual Measurement (2-point) Page (Japanese)

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Overview:
A simple, non-invasive way to understand carbohydrate impact and overall metabolism using pulse-wave changes—without measuring glucose.

Viewing glucose-related reactions through vascular responsiveness (“Carb value”)

🌿 Useful situations
・When CGM lag is a concern or you want to compare trends: CGM Lag Complementary Comparison (Japanese)
・Monitoring early signs of postprandial hyperglycemia or pre-diabetes
・Gaining hints about dyslipidemia, arteriosclerosis, or hypertension through vascular responsiveness
・Non-invasive monitoring of glucose, lipid, and blood pressure risks during pregnancy
・Feedback on diet, exercise, and sleep quality based on physiological responses
・Increasing “stable glucose days” 　Gentle glucose fluctuations may help reduce glycation, supporting skin health and focus


• Pulse Wave Analysis – Non-invasive Estimation (Technical Overview, Japanese)
Capturing inseparable interactions among glucose, lipids, proteins, vascular flexibility, insulin response, and physical activity. Beginning vascular characteristic monitoring may also support blood pressure management.

• Application Overview (General Users, Japanese)
Feature extraction and interpretation

• Model Fine-tuning with User Data (Japanese)
Machine learning and incremental training


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Carb Value Estimation App: Manual
Deriving Carb value from pulse-wave data

• Basic Usage (Manual, Japanese)
• Data Interpretation (Vascular Characteristics, ΔCarb, etc.) (Japanese)
Explanation of sample measurement data.


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Dwnload Android app. or iPhone app 測定アプリ

• for android (v2.4)　２点同時測定
このアプリはGoogle Playストアを通さずに配布されています。 インストールするには、Android端末の「提供元不明のアプリのインストールを許可」設定を有効にする必要があります。
このAPKは開発者によって署名済みのRelease版です。
更新履歴：
2ch(台)同時測定対応、2点波形比較を可能とした。　2026/02/20
測定後、VeST値の表示に対応した。　2026/03/9
インストール後の設定:
・ログインして使用ください。


• for android (v2.5)　前腕、上腕部位追加、トレンド表示
このアプリはGoogle Playストアを通さずに配布されています。 インストールするには、Android端末の「提供元不明のアプリのインストールを許可」設定を有効にする必要があります。
このAPKは開発者によって署名済みのRelease版です。
更新履歴：
測定部位に上腕を追加した。　2026/03/27
測定部位に前腕を追加した。　2026/03/30
インターバル測定時、トレンド表示を行う。　2026/03/27
測定の2重起動防止対策　2026/03/30
インストール後の設定:
・ログインして使用ください。


• for android (v2.6)　INTENTアプリ連携追加
このアプリはGoogle Playストアを通さずに配布されています。 インストールするには、Android端末の「提供元不明のアプリのインストールを許可」設定を有効にする必要があります。
このAPKは開発者によって署名済みのRelease版です。
更新履歴：
INTENTアプリ連携機能追加した。　2026/06/26
インストール後の設定:
・ログインして使用ください。


• for iPhone（v2.6 app storeに移動）
更新履歴：
タイマーインターバル最終28回目の測定保存エラー対処　2026/01/25
polar verity sense 2台接続対応　　　　　2026/01/25
info.plist NSLocationWhenInUseUsageDescription位置情報の使用を記載する2026/01/25
基準脈波ボタン（EMPTYボタン）の自動読み込みを行う　2026/01/14
インターバル停止ボタン（STOP）をホーム画面に表示　2026/01/14
Bluetooth デバイスサーチでデバイスの重複表示を回避　2026/01/14
ログイン時キャンセルした場合に、ログアウト表示になるのを回避　2026/01/14
インストール後の設定:
・ログインして使用ください。




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Research Themes Using Pulse-Wave Analysis (Carb value)

CarbSens builds on decades of blood pressure and pulse-wave research, while exploring an approach that estimates both microvascular and macrovascular conditions from wrist-based PPG signals.
Traditional methods face challenges:
・Stable measurement at the radial artery is difficult
・Fingertip PPG often distorts waveform shape
・Ring-type sensors cannot control contact pressure
・Cuff-based blood pressure devices cause discomfort and are not suitable for repeated measurements

With recent advances in LED-based PPG sensors and their integration into smartwatches,
wrist-strap devices have become suitable for continuous wear. For these reasons, CarbSens uses dorsal wrist PPG for pulse-wave analysis.

If you are considering pulse-wave analysis—or have given up on it—CarbSens offers a practical alternative.

By capturing vascular responses to glucose, hormones, nutrients, and physical activity non-invasively and in real time, CarbSens enables exploration of metabolic fluctuations and vascular responsiveness.
CarbSens is committed to supporting collaborative research and long-term development.

For example:


🩺 Early Hypoglycemia Detection (Concept)

Using Carb value and pulse-wave variability, we explore “early patterns” of reactive hypoglycemia.
CGM systems are known to have significant time lag issues:
CGM System Review Report (pp.63–64)

CarbSens measures vascular responses rather than interstitial fluid, so physiological reactions often appear earlier than CGM readings. We are developing real-time prediction using machine learning and classification models.
Reactive Hypoglycemia Prediction Research (Japanese)
CGM Lag Complementary Comparison (Japanese)

💡 Blood Pressure Research:
From cuff-based pulse-wave studies to dorsal wrist PPG analysis.

🧬 Endocrine & Hormone Research:
A new non-invasive method to capture hormone-related changes driven by meals, sleep, and physical activity through pulse-wave signals.



Food Science & Nutrition Research

🥗 Nutrition Research:
Non-invasive measurement makes repeated testing easy, without CGM-type delays.
Exploring how different foods and timing affect vascular responses, and how these relate to glucose and triglyceride dynamics.
Tracking metabolic changes during pregnancy using pulse waves to explore metabolic fluctuation and early signs of insulin resistance.

Gestational Diabetes Prediction Research
Continuous CarbSens measurements before and during pregnancy may help identify patterns associated with glucose variability.

🧠 Carotid Pulse-Wave Measurement:
Monitoring cerebral blood flow, arteriosclerosis, occlusive tendencies, and cognitive-related vascular changes.

🦶 Dorsal Pedal Artery Pulse-Wave Measurement:
Capturing early signs of diabetes-related or metabolic vascular changes.





🧭 Building a “Metabolic Map” with CarbSens and Exploring Early Signs of Cardiovascular Events (Stroke / Myocardial Infarction)

CarbSens visualizes individual metabolic fluctuations through real-time changes in glucose trends and pulse-wave signals. While respecting traditional blood pressure and pulse-wave research, CarbSens introduces a non-invasive, continuous-measurement approach to explore the relationship between metabolism and vascular responsiveness. We are particularly interested in the concept of detecting early signs of stroke and myocardial infarction from metabolic variability.

🌙 Night-time Metabolic Fluctuation and Disease Risk (Concept)
Extreme nocturnal hypoglycemia may trigger sympathetic overactivity, leading to sudden increases in heart rate and blood pressure—potential early indicators of myocardial infarction or stroke. Because the brain relies heavily on glucose, prolonged night-time hypoglycemia may weaken neuronal stability and increase the risk of cerebral blood flow interruption.

Currently, real-time measurement during sleep remains technically challenging, and development and validation are ongoing. In the future, establishing real-time monitoring of night-time metabolic fluctuations may enable a new form of preventive care—detecting risk from a “night metabolic map.”

🌅 Importance of the “Night → Morning Continuity” Layer
Stroke and myocardial infarction are known to occur more frequently in the early morning. This is associated with rapid sympathetic activation upon waking, increases in blood pressure and heart rate, heightened coagulation tendency, and abrupt hormonal shifts.

CarbSens aims to capture night-time glucose variability and morning pulse-wave changes as a continuous pattern, creating a time-based map of “night metabolic load → morning vascular response → event risk.”

🔍 Early Indicators Seen Through Metabolic Variability
・Prolonged post-meal glucose elevation → oxidative stress on vascular endothelium
・Extreme night-time glucose drops → autonomic imbalance and stress-response activation
・Different reactions to the same meal → reduced metabolic flexibility, progression of insulin resistance

By integrating these fluctuations with pulse-wave analysis, CarbSens reveals a three-layer structure of metabolism, vasculature, and autonomic function“health map.”

🩸 Detecting Vascular Risk Without Measuring Blood Pressure (Concept)
CarbSens does not measure blood pressure directly. Instead, it interprets pulse-wave amplitude, variability, and waveform changes as potential indicators of vascular abnormalities or circulatory risk.

Traditional blood pressure estimation methods (e.g., PTT) can be unstable due to vascular dilation or autonomic influences, making them less suited for daily changes in diet, sleep, and stress.

CarbSens interprets decreased pulse-wave amplitude or abnormal variability as physiological signs such as vascular constriction, impaired peripheral circulation, or sympathetic overactivity. Persistent night-time amplitude reduction may suggest abnormal vascular tone or stagnated flow, potentially serving as an early sign of myocardial infarction or stroke.

CarbSens is designed not to chase numerical precision, but to interpret the meaning of fluctuations. By visualizing interactions among metabolism, vasculature, and autonomic function, CarbSens aims to build a technology that helps individuals “sense” circulatory risk through waveform dynamics.




🧭 Dual-Point Measurement: Visualizing Peripheral Circulation and Endothelial Function

CarbSens Dual measures pulse waves simultaneously at different body sites such as both wrists, palms, ankles, or temples.

Example measurement points
・Both palms: peripheral circulation, carbohydrate response, 　and left–right autonomic nervous system asymmetry—a pattern known to show changes 　in conditions related to cognitive decline and cerebrovascular disorders.

・Ankles: lower-limb circulation, vascular left–right differences
・Temples: proximal indicator of cerebral blood flow
・Carotid artery: arteriosclerosis and pulse-wave morphology evaluation
・Inguinal region: blood-flow distribution from the abdominal aorta



Dual Measurement (CarbSens Dual) Page (Japanese)





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Japan Wellness Development Agency (JAWDA)
General Incorporated Association
一般社団法人 日本健康開発機構
Contact us here


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