Editor's Note: As the "nerve endings of the information age," sensors have permeated every critical field of the socio-economic landscape. Since October 2025, China Electronics News has invited Guo Yuansheng, Deputy Director of the Science and Technology Committee of the Jiusan Society Central Committee and Executive Vice Chairman of the China Sensor and IoT Industry Alliance, to launch the column "Guo Yuansheng on Sensors." Focusing on eight major fields and scenarios: electric power, major equipment, intelligent manufacturing, smart agriculture, smart healthcare and well-being, smart home appliances and consumer electronics, urban security, and low-altitude economy, it has successively published articles such as "Sensors 'Stationed' on the Power Generation Side: The Cornerstone of Stable Operation in New Power Systems" and "Sensors for Energy Storage Clarify Three Core Development Directions," which have received widespread attention and high praise from readers. This issue marks the first article in the smart healthcare field, focusing on medical sensors. It elaborates on their application prospects, industry status, and future recommendations to build industry consensus and promote industrial development.
In recent years, given the accelerating global aging population and the rising incidence of chronic diseases, there has been a significant shift in the health and medical needs of individuals and families, presenting explosive growth. Data from the National Health Commission shows that in 2024, China's population aged 60 and above reached over 310 million, with chronic disease patients such as those with hypertension and diabetes accounting for over 75%. Meanwhile, the scale of the sub-healthy population has exceeded 300 million, making regular monitoring of physiological indicators a rigid demand for daily health management.
As core components in the field of biomedical engineering, medical sensors are no longer "precision instruments" exclusive to hospitals. They are entering ordinary homes as "home health gatekeepers," reshaping the landscape of medical health management. By converting human physiological signals (such as pulse, ECG, blood pressure, galvanic skin response, gait, body temperature, respiratory gases, urine composition, etc.) into quantifiable electrical signals, they enable real-time monitoring of health status, disease early warning, and rehabilitation assessment, becoming a key bridge connecting biomedicine and engineering technology. From smart mattresses monitoring sleep and respiration, to smart toilets analyzing urine composition, and flexible ECG patches tracking heart health, medical sensors are penetrating all scenarios of home life—eating, sleeping, toileting, and exercising—in diverse forms, becoming the "vanguard" in chronic disease management and technology-assisted elderly care.
However, the public's perception of medical sensors still faces a "professional barrier": people know smart bracelets can measure heart rate but do not understand the optical sensor principles behind them; when using smart toilets for health detection, they are unaware of the medical significance of different test results; faced with a dazzling array of home medical devices on the market, it is difficult to judge whether their sensor accuracy meets standards or suits their own health needs.
I. Technical Classification, Indicators, and Functions of Medical Sensors
Classification by Sensitive Mechanism and Materials
The core materials of medical sensors directly affect their sensitivity, biocompatibility, service life, and cost. Different materials correspond to different application scenarios and can be specifically divided into three categories: silicon-based materials, flexible materials, and bioactive materials:
1. Silicon-Based Material Sensors: High precision and high integration, suitable for professional medical equipment and high-end home devices.
Silicon-based materials (monocrystalline silicon, polycrystalline silicon) are the core of MEMS (Micro-Electro-Mechanical Systems) technology. Through micro-machining processes, sensor components with small size and high precision can be manufactured. They are characterized by strong stability and long lifespan (up to 5-10 years), but poor flexibility, making them unsuitable for skin adhesion or implantation.
Technical Advantages: The accuracy of silicon-based pressure sensors can reach ±0.1% FS (Full Scale), and the resolution of silicon-based optical sensors can reach 1μm, suitable for scenarios requiring high-precision monitoring, such as hospital monitors and high-end smart mattresses.
2. Flexible Material Sensors: Good flexibility and high biocompatibility, suitable for wearable devices and body surface monitoring.
Flexible materials (polyimide, graphene, carbon nanotubes, hydrogels) possess excellent flexibility and stretchability, allowing them to conform to the skin surface or deform with human movement, while also exhibiting good biocompatibility (less likely to cause skin allergies). They are suitable for manufacturing wearable bracelets, ECG patches, smart bandages, etc.
Technical Advantages: Flexible sensors can be stretched to 200%-500% of their original length (e.g., graphene sensors can be stretched by 300%), with a thickness of only 0.1-1mm and lightweight (a single flexible ECG sensor weighs <1g), making them suitable for long-term wear.
Technical Difficulties and Breakthroughs: The long-term stability of flexible sensors is a challenge. Traditional flexible materials are prone to fatigue fracture after repeated stretching (e.g., polyimide sensors experience a 30% drop in sensitivity after 1,000 stretches). In recent years, domestic research institutions have improved the anti-fatigue performance of materials by adding nanofibers (such as cellulose nanofibers) to flexible materials, enabling sensors to withstand 10,000 stretches (equivalent to wearing them for 8 hours a day for 1 year) with only a 5% drop in sensitivity. This technology has been applied to Xiaomi's flexible blood oxygen bracelet.
3. Bioactive Material Sensors: Contain biological molecules, suitable for Point-of-Care Testing (POCT) and home test strips.
Bioactive materials (immobilized enzymes, monoclonal antibodies, DNA probes, biological membranes) are the core of biosensors. They can specifically recognize target substances, characterized by fast detection speed and low sample demand, suitable for manufacturing home test strips, portable detectors, and other POCT devices.
Technical Advantages: Bioactive materials have strong specificity and can accurately identify target substances in complex samples (such as blood and urine) without complex sample pretreatment (such as centrifugation and extraction), making them suitable for self-operation by home users.
Storage and Usage Precautions: Bioactive materials are sensitive to temperature and humidity. For example, blood glucose test strips must be used within 3 months after opening to avoid moisture (when humidity >80%, enzyme activity will drop by 50%). COVID-19 antigen test strips need to be stored in a 2-30℃ environment, avoiding direct sunlight (UV rays will destroy the antibody structure, leading to test failure). Before use, the test strip should be taken out of the packaging and placed at room temperature for 10 minutes before sampling to avoid low temperatures affecting the reaction speed.
Classification by Sensitive Elements and Sensors
The sensitive mechanism of medical sensors refers to their use of sensitive materials to convert human physiological signals into electrical signals, which can be specifically divided into three categories: physical, chemical, and biological:
1. Physical Sensors: Detect physiological indicator signals relying on physical characteristic changes. Utilizing physical changes such as electrical, mechanical, and optical changes in human physiological activities, they convert them into measurable electrical signals. They are characterized by fast response speed and strong stability, suitable for real-time monitoring of vital signs.
(1) Electrocardiogram (ECG) Sensors: Based on the electrical principle of heart activity, when the human heart beats, myocardial cells generate weak electrical signals (about 0.5-4mV). The sensor collects these signals through body surface electrodes (divided into dry and wet electrodes), amplifies them 1000-5000 times via an amplifier, and outputs the ECG waveform.
(2) Blood Pressure Sensors: Based on pressure changes in mechanical principles. By compressing the artery with a cuff, it detects the pressure oscillation wave during arterial pulsation, and then converts it into systolic and diastolic blood pressure through algorithms. Measurement range 0-299mmHg, accuracy ±3mmHg (meeting medical-grade standards), built-in intelligent pressurization technology automatically adjusts cuff pressure according to the user's arm circumference, reducing the feeling of compression during measurement.
(3) Blood Oxygen Sensors: Utilizing the light absorption characteristics of hemoglobin in optical principles. When red light (660nm) and infrared light (940nm) penetrate finger skin, the light absorption rates of oxygenated hemoglobin and deoxygenated hemoglobin differ. The sensor calculates blood oxygen saturation (SpO2) by detecting changes in transmitted light intensity.
2. Chemical Sensors: Detect signals through chemical reactions, suitable for measuring body fluid/gas components. Through the reaction of sensitive materials with chemical substances in human body fluids (blood, urine, saliva) or gases (exhaled breath, intestinal gases), electrical signals are generated. They are characterized by high detection accuracy and strong specificity, suitable for chronic disease indicators and metabolite monitoring.
(1) Blood Glucose Sensors: Based on enzyme catalysis chemical principles, commonly using glucose oxidase (GOD) as the sensitive material. When glucose in the blood reacts with GOD, hydrogen peroxide is produced. The sensor converts the electrical signal intensity of hydrogen peroxide into blood glucose concentration.
(2) Gas Sensors: Based on semiconductor or electrochemical principles. When different gases contact the sensitive materials of the sensor (such as tin dioxide, zinc oxide), it causes changes in material resistance or electrochemical reaction current, thereby identifying gas types and concentrations. In homes, they are mainly used to detect exhaled breath, intestinal gases, and indoor environmental gases.
(3) Breath Alcohol Sensors: Using semiconductor gas sensors (sensitive material is tin dioxide). When alcohol molecules in exhaled breath contact the sensor, the resistance of tin dioxide decreases, and the electrical signal enhances. Through algorithms, it is converted into blood alcohol concentration (BAC). Response time <3 seconds, measurement range 0-1.00% BAC, error ±0.01% BAC, suitable for self-checking after drinking and driving. (4) Intestinal Gas Sensors: Smart toilet seats use electrochemical gas sensors to detect hydrogen (H₂), methane (CH₄), and hydrogen sulfide (H₂S) excreted by the intestines: hydrogen >20ppm indicates lactose intolerance; methane >15ppm indicates constipation (slow intestinal peristalsis); hydrogen sulfide >5ppm indicates intestinal inflammation (such as colitis). Test results are synchronized to a mobile APP and provide dietary advice (e.g., when hydrogen exceeds the standard, it is recommended to reduce milk and cheese intake).
(5) Blood Gas Sensors: Based on ion-selective electrode principles, different electrodes detect the pH value (acidity/alkalinity), partial pressure of oxygen (PO₂), and partial pressure of carbon dioxide (PCO₂) in the blood respectively. Mainly used for monitoring critically ill patients, in homes, they are mostly integrated into portable blood gas analyzers.
3. Biosensors: Detect signals through biological molecule recognition, suitable for measuring "highly specific" biomarkers.
Utilizing specific binding reactions of biological molecules such as antigen-antibody, DNA-nucleic acid, and enzyme-substrate, they detect biomarkers in the human body such as tumor markers, viruses, and hormones. They are characterized by a specificity of over 95%, suitable for early disease screening and precise diagnosis.
(1) Immunosensors: Based on specific antigen-antibody binding, antibodies are fixed on the sensor surface. When antigens in the blood (such as tumor markers CEA, AFP) bind to the antibodies, it causes changes in electrical signals (such as impedance, capacitance) on the sensor surface, thereby quantitatively detecting antigen concentration.
(2) DNA Sensors: Based on DNA nucleic acid hybridization principles, DNA probes related to specific viruses or diseases are fixed on the sensor surface. When DNA in the sample binds complementarily to the probe, it generates fluorescence or electrical signals, used for virus infection and genetic disease detection. Technical Advantages: Compared with traditional PCR testing, DNA sensors do not require complex instruments and equipment, and sample processing is simple (only requiring soaking the sampling brush in physiological saline), suitable for use in grassroots homes and remote areas. The National Health Commission has included it as a recommended testing method for the "Two Cancers Screening" (cervical cancer and breast cancer).
(3) Enzyme Sensors: Based on specific catalytic reactions between enzymes and substrates. Besides the common glucose oxidase sensors (for measuring blood glucose), there are also lactate enzyme sensors (for measuring lactate), uricase sensors (for measuring uric acid), etc., used for sports health and chronic disease monitoring.
Classification by Structure and Function
The device structure of medical sensors determines how they collect signals, process signals, and connect with other devices. From components to systems, they can be divided into three parts: core sensitive elements, signal conversion modules, and medical packaging and interfaces. The three work synergistically to achieve complete detection functions:
1. Core Sensitive Elements: The "antennae" that "perceive" signals, directly contacting the measured object. Responsible for converting human physiological signals into physical/chemical changes, they are the foundation of detection. They can be divided into:
(1) Sensitive elements of physical sensors: such as electrodes of ECG sensors (collecting electrical signals), pressure membranes of blood pressure sensors (sensing pressure changes), and light-emitting diodes and photodiodes of blood oxygen sensors (emitting/receiving optical signals).
(2) Sensitive elements of chemical sensors: such as enzyme electrodes of blood glucose sensors (the area where enzymes react with glucose), and sensitive layers of gas sensors (semiconductor or electrochemical material layers reacting with gases).
(3) Sensitive elements of biosensors: such as antibody fixation layers of immunosensors (the area fixing antibodies), and probe fixation layers of DNA sensors (the area fixing DNA probes).
2. Signal Conversion Module: Converts physical/chemical changes into standardized electrical signals. Main components: amplifiers (amplifying weak signals), filters (removing interference signals), AD converters (converting analog signals to digital signals), and microcontrollers (processing digital signals and calculating detection results).
3. Medical Packaging and Interfaces: The "protective shell" and "connectors," ensuring safety and compatibility. Medical sensors directly contact the human body (such as skin, blood, body fluids) and need to connect with hosts, mobile phones, and hospital systems. It is necessary to ensure biocompatibility, waterproofness, and durability; interfaces are responsible for data transmission, ensuring compatibility and stability.
(1) Medical packaging must meet three major requirements: ① Biocompatibility: Packaging materials in contact with the human body must comply with the ISO 10993 standard, with no skin irritation, no cytotoxicity, avoiding allergies or infections; ② Protection performance: Possessing waterproof, dustproof, and anti-corrosion capabilities (such as IP67/IP68 waterproof ratings, capable of handling sweat, urine, and rainwater immersion); ③ Structural adaptation: Designing shapes according to usage scenarios, such as adhesive sensors needing to be thin and soft, and implantable sensors needing to be small and smooth to reduce human discomfort.
(2) Interface Design: The bridge connecting to external devices (hosts, mobile phones, hospital systems) must meet the requirements of fast data transmission speed, high stability, and strong compatibility. Common interface types for home sensors include wired interfaces (USB, Micro-USB, Type-C) and wireless interfaces (Bluetooth, Wi-Fi, NFC, LoRa).
II. Sensor Application Practices in Home Health Scenarios
The application of medical sensors in homes has long surpassed basic functions like "measuring heart rate and blood pressure." Instead, they are deeply integrated into scenarios such as daily living, chronic disease management, and postoperative rehabilitation, becoming "home health butlers." Through the combined use of different sensors, home users can achieve the transformation from "passive medical treatment" to "proactive health management."
Daily Health Monitoring Scenarios: Covering "eating, sleeping, exercising, and toileting," capturing health signals in real time.
The core of daily health monitoring is "high frequency, non-invasive, and convenient." By deploying sensors in life scenarios such as diet, sleep, exercise, and toileting, subtle changes in the body (such as sleep apnea, intestinal flora imbalance, over-exercising) can be detected in time, providing early warnings for health risks.
1. Sleep Monitoring: Pressure + Optical + Millimeter-Wave Sensors for Precise Sleep Quality Analysis
Sleep problems (such as insomnia, sleep apnea, excessive dreaming) are often early signals of cardiovascular diseases and depression. Home sleep sensors can continuously monitor sleep status through non-invasive methods without wearing devices, without affecting the sleep experience.
(1) Contact Sleep Sensors: Smart mattresses/sleep pillows capture body movement, respiration, and heart rate through pressure sensors. Smart mattresses are built-in with 108 silicon-based pressure sensors (distributed in the shoulder, waist, hip, and leg areas), with a sampling rate of 50Hz. Combined with edge computing chips, they can judge sleep stages such as light sleep, deep sleep, and REM (Rapid Eye Movement) through pressure changes, and detect sleep apnea warnings; they can also analyze sleeping posture health such as supine, left lateral, right lateral, and prone positions through pressure distribution.
(2) Non-Contact Sleep Sensors: Millimeter-wave radar + smart bracelets, monitoring without contact or sensation. Using 60GHz millimeter-wave technology, it can penetrate bed sheets and thin quilts (thickness <5cm), with a detection distance of 0.5-2m. It monitors respiration and heart rate and provides out-of-bed warnings without wearing any devices, suitable for nighttime safety monitoring of elderly living alone (avoiding situations where no one knows after a fall). It can also link with air conditioners and humidifiers. When detecting the user entering the deep sleep stage, it automatically raises the air conditioner temperature by 1℃ (to avoid catching a cold) and adjusts the humidifier humidity to 50%-60% (optimizing the sleep environment).
2. Exercise Monitoring: Optical + Inertial + Pressure Sensors for Scientific Exercise Intensity Guidance.
Improper exercise (such as excessive running leading to knee injuries, or incorrect strength training postures leading to muscle strains) can instead harm health. Home exercise sensors can monitor exercise type, intensity, and posture in real time, providing personalized guidance to avoid sports injuries.
Running Monitoring: Smart running shoes/sports watches capture cadence, stride length, and foot strike pattern;
Strength Training Monitoring: Smart fitness mirrors/smart bracelets correct movements and monitor muscle load;
Personalized Training Plans: Adjusting training intensity based on user historical movement data and recommending targeted training;
Post-Exercise Recovery Advice: Recommending recovery methods based on heart rate recovery speed (e.g., if recovery is poor, recommending foam roller relaxation instead of continuing training).
3. Toileting Monitoring: Gas + Urine + Pressure Sensors for Early Screening of Digestive System Diseases.
Toileting is an important window reflecting digestive system health. Through sensors in devices such as smart toilets and urine analyzers, intestinal gases and urine components can be non-invasively detected, discovering problems like gastritis, enteritis, and diabetes in advance.
Smart toilet seats assess intestinal health by analyzing the concentration of intestinal gases such as hydrogen, methane, and hydrogen sulfide, warning of intestinal inflammation (such as ulcerative colitis, Crohn's disease), and evaluating the ability of intestinal bacteria to decompose proteins; using optical sensors (test strip colorimetric method) can detect 11 indicators such as urine glucose, urine protein, urine ketones, and urine occult blood for diabetes screening and control, kidney health monitoring, and urine ketone positive analysis for fat-loss population monitoring.
4. Diet Monitoring: Optical + Weight Sensors to Quantify Nutritional Intake and Avoid Dietary Imbalance.
Unbalanced diet (such as high oil and high salt, insufficient protein intake) is a major inducer of chronic diseases. Home diet sensors can help users reasonably match their diet by identifying food types and weighing them to calculate calories and nutritional components.
Smart plates/food scales: Weight + optical sensors for precise calculation of calories and nutrition. Built-in weight sensors (accuracy ±1g) and optical cameras (2 million pixels) can realize functions such as food type identification, calorie and nutrition calculation, dietary balance reminders, and dietary preference analysis.
Chronic Disease Management Scenarios: Blood Glucose + Blood Pressure + Heart Rate + Blood Oxygen Sensors, Home Monitoring Replacing Partial Hospital Follow-ups.
Chronic diseases (such as diabetes, hypertension, coronary heart disease) require long-term monitoring of indicator changes. Home medical sensors can achieve high-frequency daily monitoring, synchronizing data to the doctor's end, reducing hospital visits, and promptly detecting abnormal fluctuations to avoid complications.
1. Diabetes Management: Blood Glucose Sensors + Insulin Pumps for Closed-Loop Blood Glucose Management
The core of diabetes management is the closed loop of "blood glucose monitoring - insulin injection - diet and exercise adjustment." Home sensors can achieve real-time blood glucose monitoring and link with insulin pumps to automatically adjust insulin doses, reducing the risk of hypoglycemia.
(1) Continuous Glucose Monitoring (CGM): Optical + enzyme biosensors for continuous monitoring of blood glucose fluctuations.
Sensor Principle: Using enzyme biosensors (glucose oxidase), after implantation into the abdominal subcutaneous tissue, the enzyme reacts with glucose in the interstitial fluid, generating a weak current (the current magnitude is proportional to the glucose concentration). The optical sensor converts the current signal into a blood glucose value, recording once every 15 minutes for continuous monitoring for 14 days.
Core Functions: ① Real-time blood glucose display: The reader can read the current blood glucose (range 2.2-22.2mmol/L, accuracy ±10%, meeting international ISO 15197:2013 standards) by approaching the sensor, without fingertip blood collection; ② High/low blood glucose warning: When blood glucose is <3.9mmol/L (hypoglycemia) or >16.7mmol/L (hyperglycemia), the reader vibrates to alarm, and the mobile APP pushes a reminder; ③ Blood glucose fluctuation analysis: Generating daily blood glucose curves, marking postprandial blood glucose peaks (normal postprandial 2-hour blood glucose <7.8mmol/L, if the peak >10mmol/L, it indicates diet needs adjustment), nighttime blood glucose troughs (avoiding early morning hypoglycemia), and calculating the "Time in Range (TIR)" (ideal TIR ≥70%, if <50%, it indicates insulin dose or diet needs optimization).
Real-Time Sharing Function: Blood glucose data can be shared with family members and doctors. When blood glucose is abnormal, family members' mobile phones receive simultaneous alerts; doctors can view the patient's 14-day blood glucose data through the cloud platform and remotely adjust insulin doses.
(2) Insulin Pumps: Pressure sensors + micro-motors for precise insulin infusion.
Integrating blood glucose sensors, pressure sensors (monitoring whether the infusion pipeline is blocked), and micro-motors (precisely controlling insulin doses) to achieve "sensor-pump" closed-loop control.
2. Hypertension Management: Electronic Blood Pressure Monitors + Heart Rate Sensors for Precise Measurement + Fluctuation Analysis
The key to hypertension management is "accurate blood pressure measurement + recording fluctuation patterns + taking medication as prescribed." Home electronic blood pressure monitors, through pressure sensors and heart rate sensors, can achieve clinic-grade precision measurement and help users discover "masked hypertension" (such as nocturnal hypertension, white-coat hypertension).
Upper-arm electronic blood pressure monitors: Pressure sensors + oscillometric method for precise blood pressure measurement. It can generate a PDF report of 1 month's blood pressure data and send it to the doctor via WeChat. The doctor adjusts medication based on fluctuation patterns (e.g., changing nifedipine controlled-release tablets from once daily to twice daily to control the afternoon blood pressure peak).
3. Coronary Heart Disease/Heart Failure Management: Heart Rate + Blood Oxygen + Weight Sensors for Early Warning of Acute Attacks
Patients with coronary heart disease and heart failure need to focus on monitoring changes in heart rate, blood oxygen, and weight (sudden weight gain indicates worsening heart failure). Home sensors can monitor key indicators in real time, promptly detect precursors of acute attacks, and reduce the risk of sudden death.
(1) Smart Bracelets/Watches: Optical heart rate + blood oxygen sensors for real-time early warning of abnormalities. Heart rate abnormality monitoring and warning, prompting possible myocardial ischemia, hyperthyroidism, etc., the watch vibrates to alarm and pushes "recommend visiting a doctor for an ECG check"; detecting irregular rhythms through heart rate sensors, when atrial fibrillation lasts >10 minutes, the watch prompts "suspected atrial fibrillation attack" and generates an ECG report (supports export to PDF for doctor diagnosis). Atrial fibrillation is an important inducer of stroke, and early detection can reduce the risk of stroke by 70%. Continuous blood oxygen saturation <92% indicates insufficient myocardial oxygen supply (possibly due to aggravated coronary artery stenosis), requiring immediate rest and oxygen inhalation; for heart failure patients, blood oxygen <90% indicates aggravated pulmonary edema, requiring emergency medical treatment.
(2) Smart Weight Scales: Pressure sensors + body fluid analysis for early warning of worsening heart failure.
Using high-precision pressure sensors (accuracy ±0.1kg), combined with bioelectrical impedance technology, it can realize functions such as weight fluctuation monitoring, body fat rate and muscle mass tracking, edema risk assessment, and drinking water reminders.
Home Rehabilitation and Nursing Scenarios: Joint Range of Motion + Muscle Strength + Wound Monitoring Sensors to Aid Postoperative/Chronic Disease Rehabilitation
Home rehabilitation is a key link for postoperative patients (such as joint replacement, fractures) and chronic disease patients (such as post-stroke sequelae, COPD) to recover function. Home rehabilitation sensors can monitor the quality of rehabilitation movements and muscle strength recovery in real time, avoiding secondary injuries caused by incorrect training, while reducing visits to rehabilitation institutions.
1. Joint Rehabilitation: Inertial Sensors + Angle Sensors to Correct Joint Range of Motion Training
After joint surgery (such as knee joint replacement, shoulder joint rotator cuff repair), joint range of motion training (such as knee flexion/extension, shoulder joint abduction) is required. Sensors can capture joint angle changes, ensuring the training amplitude meets the standards and does not exceed the safe range (avoiding joint dislocation or wound dehiscence caused by over-activity).
Smart joint rehabilitation devices: Angle sensors + vibration feedback for precise control of the range of motion. Using high-precision angle sensors (measurement range 0°-150°, accuracy ±1°), combined with electric drive and vibration feedback modules, suitable for early postoperative rehabilitation of knee joints; providing passive training mode, active training mode, rehabilitation progress tracking, movement recognition and correction, as well as common shoulder joint rehabilitation movements (such as pendulum exercises, forward raises, lateral raises), resistance training monitoring, and fatigue warning functions.
2. Muscle Strength Rehabilitation: Pressure Sensors + Electromyography Sensors to Quantify Muscle Force and Activation
Muscle atrophy (such as post-stroke hemiplegia, disuse atrophy caused by long-term bed rest) requires strength training. Sensors can quantify muscle force and activation degree, helping patients gradually recover muscle strength and avoiding movement compensation caused by insufficient force (such as using healthy side muscles to compensate for the affected side, affecting recovery results).
(1) Smart Grip Strengtheners: Pressure sensors + Bluetooth for monitoring hand muscle strength. Built-in high-precision pressure sensors (measurement range 5-100kg, accuracy ±0.5kg), supporting connection to mobile APPs, suitable for muscle strength grading monitoring, personalized training plans, and bilateral comparative analysis for patients with hand dysfunction post-stroke and hand postoperative rehabilitation.
(2) EMG Biofeedback Devices: EMG sensors + electrical stimulation to activate paralyzed muscles. Using surface EMG sensors (sampling rate 1000Hz) and low-frequency electrical stimulation modules, suitable for muscle activation monitoring, electrical stimulation-assisted training, and rehabilitation effect quantification for patients with muscle paralysis caused by post-stroke hemiplegia and spinal cord injuries.
3. Wound Monitoring: Optical Sensors + Temperature Sensors for Early Warning of Postoperative Wound Infections
Postoperative wounds (such as cesarean section wounds, diabetic foot ulcers, pressure ulcers) need close monitoring of redness, swelling, exudate, and temperature changes. Traditional naked-eye observation easily misses early infection signals. Smart wound monitoring sensors can detect abnormalities in real time, reducing the risk of infection deterioration (such as cellulitis, sepsis), and monitoring wound status in real time.
Optical sensors (detecting exudate color and transparency), temperature sensors (accuracy ±0.5℃), and Bluetooth modules are suitable for chronic wounds and postoperative sutured wounds: analyzing exudate color and humidity through reflected light (normal wound humidity 30%-50%, too wet easily leads to skin maceration, too dry affects healing), and tracking healing progress.
III. Core Technical Challenges, Solutions, and Data Security and Privacy Protection
Home health sensors need to break through the dual difficulties of "technology adapting to scenarios" and "data security utilization." In terms of core technology, through hardware optimization, algorithm upgrades, and standard unification, issues of stability, compatibility, and precision compensation are solved to achieve medical-grade data quality. In terms of data security and privacy, with "minimum necessity + hierarchical authorization" as the core, it not only ensures that user data is not leaked or abused, but also allows family doctors, hospitals, and the government to utilize data within a reasonable range through hierarchical sharing of electronic medical records, truly realizing the closed loop of "home monitoring - professional diagnosis and treatment - public prevention and control."
Core Technical Challenges
The scenario-based implementation and medical-grade performance realization of home health sensors require facing multi-dimensional technical bottlenecks. These challenges stem not only from the complexity of the home environment (such as temperature fluctuations, electromagnetic interference, human movement interference) affecting sensor stability, but also from compatibility issues caused by protocol differences between different devices. More core is the contradiction between the demand for low cost in home scenarios and the requirement for medical-grade data accuracy, which urgently needs to be broken through targeted technological innovation.
1. Stability Challenges. Problem: Sensor signal drift after long-term use (e.g., optical heart rate sensors working continuously for 8 hours, error expanding from ±2 beats/min to ±5 beats/min); environmental interference (electromagnetic signals from microwave ovens, routers, etc., causing ECG sensor waveform noise, misjudging arrhythmias); insufficient power endurance (dynamic blood glucose monitors generally last 7-14 days, power failure easily leads to data interruption). Impact: Inaccurate data may mislead family doctors' judgment of the condition, such as long-term drift of blood pressure monitors leading to improper medication adjustments for hypertension patients.
2. Compatibility Challenges. Problem: Data formats of sensors from different brands are not interoperable; poor adaptation between devices and older models, incompatible communication modes; difficulty in multi-sensor data fusion (inconsistent sampling frequencies of heart rate, blood oxygen, and body temperature, timestamp error >0.5 seconds, unable to associate abnormal linkage patterns). Impact: Users need to manually enter data, increasing operation costs and prone to errors; family doctors cannot integrate multi-dimensional data, making it difficult to comprehensively evaluate health status.
3. Precision Compensation Challenges. Problem: Temperature interference (when ambient temperature is <10℃ or >35℃, the heart rate measurement error of optical sensors increases by ±3 beats/min); movement interference (the signal-to-noise ratio of blood oxygen sensors decreases during walking, measured values are3%-5% lower); individual differences (large deviations among people with different skin colors and ages). Impact: Insufficient data accuracy may miss early health risk signals.
Targeted Solutions
Aiming at the core technical pain points in home scenarios, a systematic solution needs to be constructed from three dimensions: hardware, algorithms, and standards, to precisely solve key problems such as stability, compatibility, and precision compensation.
1. Stability Improvement Solutions
(1) Hardware Optimization: Using ceramic pressure diaphragms (extending the service life of electronic blood pressure monitors from 6 months to 2 years, error controlled within ±3mmHg); adding copper foil electromagnetic shielding layers (reducing 90% of external interference, ECG sensor noise amplitude reduced from 0.5mV to below 0.05mV).
(2) Power Management: Introducing low-power chips (such as Nordic nRF52840, extending the endurance of wearable ECG sensors from 24 hours to 72 hours); supporting emergency power supply mode (when battery <10%, prioritizing the retention of core data from the last 2 hours).
(3) Algorithm Optimization: Adaptive Kalman filtering algorithm (reducing heart rate error during exercise from ±5 beats/min to ±2 beats/min); intelligent baseline calibration (weight scales automatically zero-calibrate before each use, accuracy improved from ±0.2kg to ±0.1kg).
2. Compatibility Resolution Strategies
(1) Unified Data Standards: Following the HL7 FHIR medical data interoperability standard, promoting brands like Huawei, Xiaomi, and Apple to open interfaces, achieving seamless data synchronization to third-party health platforms (such as DXY Doctor), with adaptation rate increased to over 95%.
(2) Cross-Platform Adaptation: Developing multi-terminal compatible lightweight APPs (supporting iOS, Android, HarmonyOS, memory occupation reduced from 500MB to 200MB); launching device linkage middleware (connecting oxygen concentrators and smart bracelets of different brands via USB-C/Wi-Fi, automatically increasing oxygen concentration when blood oxygen <92%).
(3) Multi-Sensor Fusion: Timestamp alignment + synchronous sampling (unifying sampling frequency to 1Hz, error ≤0.1 seconds); machine learning model fusion (combining HRV, skin temperature, and activity data, anxiety state recognition accuracy reaches 88%).
3. Precision Compensation Technologies
(1) Environmental Compensation: Integrating NTC thermistors (heart rate error ≤±2 beats/min in environments from -10℃ to 40℃); waterproof breathable membrane + humidity sensor (when skin humidity >80%, automatically compensating blood pressure value by ±5mmHg).
(2) Movement Compensation: Dual-sensor fusion (PPG optical sensor + IMU inertial sensor, blood oxygen error reduced from ±5% to ±2%); individual movement model (collecting 3 minutes of user movement data for the first time, targeted elimination of interference).
(3) Individual Difference Compensation: Multi-wavelength LED skin color compensation (blood oxygen error ≤±2% for dark-skinned users); children's dedicated flexible sensors (fitting the wrist, heart rate error ≤±3 beats/min, meeting pediatric equipment standards).
Data Security and Privacy Protection
The popularization of home health sensors is accompanied by the generation and flow of massive sensitive physiological data. Data security and privacy protection have become key issues restricting the construction of industry trust systems.
1. Core Issues
(1) Excessive Data Collection: Some APPs force authorization of irrelevant permissions such as contacts and geographic location (e.g., a certain blood glucose meter APP cannot synchronize data if location authorization is refused); manufacturers sell de-identified health data to third parties for advertising promotion.
(2) Transmission and Storage Risks: Bluetooth 2.0 sensors are unencrypted, and data is easily sniffed and restored (including user names, blood pressure values); cloud servers of small manufacturers have not passed Level 3 classified protection, and plaintext storage leads to data leakage (over 30,000 ECG data records leaked in a certain region in 2024).
(3) Device and Lifecycle Security: No identity verification (others can view historical data after device loss); second-hand devices lack one-click clearing functions (cache can restore previous users' blood glucose and blood pressure data).
(4) Electronic Medical Record Sharing Hidden Dangers: Lack of hierarchical authorization mechanisms may lead to excessive exposure of sensitive medical histories (such as cancer, mental illness), infringing on user privacy.
2. Solutions
(1) Data Collection and Usage Norms: Only apply for necessary permissions such as Bluetooth and storage (connecting devices does not require obtaining geographic location/contacts); for personal health analysis/abnormal warnings, not used for commercial promotion, providing a data sharing switch (turning it off does not affect core functions).
(2) Transmission and Storage Encryption: End-to-end encryption; TLS 1.3 protocol, data cannot be cracked throughout the process.
(3) Device and Lifecycle Management: Mobile phone number/account binding + secondary verification; NFC identity recognition.
3. Hierarchical Sharing Mechanism for Electronic Medical Records
(1) Hierarchical Authorization Architecture: Basic health data: Heart rate, blood pressure, body temperature, etc., are fully open to family doctors, supporting daily monitoring and medication guidance; detailed medical data: Medical history, surgical records, ECGs, blood glucose trends, etc., are only open to attending doctors in contracted hospitals, requiring secondary user authorization; aggregated anonymous data: Regional hypertension prevalence, diabetes age distribution, etc., are open to government public health departments with user consent for policy formulation and disease prevention and control.
(2) Security Guarantee: Each level of sharing requires explicit user authorization, and authorization records are kept for 10 years for inspection; anonymous data removes all personal identifiers (such as name, mobile phone number, address), retaining only statistical information such as age, gender, and region to prevent reverse identification of user identity.
4. Hierarchical Authorization Mechanism and Rules for Electronic Medical Records
(1) Level 1 Authorization: Daily diagnosis and treatment authorization (local encrypted transmission); open objects: family doctors; open data: basic health data (heart rate, blood pressure, body temperature, daily blood glucose fluctuations, etc.); authorization method: one-time authorization when the user first binds a family doctor, data is encrypted locally and transmitted to the family doctor's exclusive platform. Family doctors can view data trends in real time for daily monitoring (such as tracking daily blood pressure changes of hypertension patients) and medication guidance (such as adjusting hypoglycemic drug doses based on blood glucose data). Data access records are synchronized to the user APP in real time.
(2) Level 2 Authorization: Cross-hospital treatment authorization (temporary authorization code mechanism); open objects: attending doctors in contracted cooperative hospitals; open data: detailed medical data (medical history, surgical records, original ECG waveforms, detailed blood glucose fluctuation curves, allergy history, etc.); authorization method: before referral or cross-hospital consultation, the user generates a temporary authorization code valid for 72 hours through the APP. After the attending doctor enters the authorization code, they can access data for the specified time period. The authorization automatically expires after expiration to prevent long-term data exposure, and users can revoke the authorization in advance in the APP at any time.
(3) Level 3 Authorization: Public health authorization (anonymized aggregation); open objects: government public health departments; open data: aggregated anonymous health data (regional hypertension/diabetes prevalence, health indicator distribution in different age groups, seasonal disease high-incidence trends, etc.); authorization method: after the user actively checks and agrees in the APP, the system de-identifies the data (deleting personal information such as name, mobile phone number, address, retaining only statistical dimensions such as age, gender, and region), and transmits it to the public health department after encrypted aggregation for regional health policy formulation (such as increasing community screening points based on high-incidence diabetes trends) and disease prevention and control (such as allocating medical resources in advance during flu season), ensuring that user identity cannot be reverse-identified through the data.
In conclusion, the development of home health sensors lies in balancing technical practicality and data security. By solving key technical challenges such as stability, compatibility, and precision compensation, reliable data support can be provided for home health monitoring; and the three-level authorization mechanism based on local encryption not only ensures that user privacy is not leaked, but also allows health data to flow reasonably in scenarios such as daily diagnosis and treatment, cross-hospital treatment, and public health. In the future, as technology continues to optimize, such sensors will better connect families and the medical system, becoming a strong support for technology-assisted elderly care and building a solid technical backing for home health management.
(The next issue of this column will feature "Smart Healthcare Sensors (Part 2)", stay tuned!)
Author | Guo Yuansheng, Deputy Director of the Science and Technology Committee of the Jiusan Society Central Committee, Executive Vice Chairman of the China Sensor and IoT Industry Alliance
Editor | Yang Pengyue Art Editor | Maria Supervisor | Zhao Chen