The medical sensor is a part of the sensor used in the field of biomedicine. It is a device that converts the physiological information of a human body into electric information with a definite functional relationship with it. The information it picks is the body's physiological information, and its output is often represented by electrical signals. Physiological information There are two types of electrical information and non-electrical information, from the distribution of the body (such as blood pressure and other types of pressure), but also the surface (such as ECG and other bioelectricity) and in vitro (such as infrared , Bio-magnetic, etc.).
Medical sensor basic requirements
As an important branch of the sensor, the medical sensor must consider the influence of the human factors in the design and application of the sensor. Considering the particularity and complexity of the biological signal, the biocompatibility, reliability and safety of the biomedical sensor should be considered.
1, the sensor itself has good technical performance, such as sensitivity, linearity, hysteresis, repeatability, frequency response range, signal to noise ratio, temperature drift, zero drift, sensitivity drift and so on.
2, The shape and structure of the sensor should be adapted to the anatomical structure of the test site. When used, the damage to the tested tissue should be small.
3, the impact of the sensor on the measured object is small, will not burden the physiological activity, does not interfere with normal physiological function.
4, the sensor must have enough solidity, when introduced to the test site, will not fall off, damage.
5, the sensor and the human body have enough electrical insulation to ensure human safety.
6, the sensor into the human body to adapt to the chemical role of the body, compatible with the chemical composition of the body, not easily corroded, no adverse human stimulation, and non-toxic.
7, the sensor into the blood or buried in the body for a long time, should not cause blood clots.
8, the sensor should be simple to operate, easy maintenance, structural ease of disinfection.
Use of medical sensors
Detection of biological information
Such as heart pressure testing before cardiac surgery; the basic research of cardiovascular disease need to test the blood viscosity and blood lipid levels.
Clinical care
Such as patients before and after the need for continuous testing of body temperature, pulse, blood pressure, respiration, ECG and other physiological parameters.
control
Use the detected physiological parameters to control the body's physiological processes. Such as electronic prostheses.
Medical sensor classification
By application form points
Implantable sensors, Temporary implanted body cavity (or incision) sensors, In vitro sensors, Sensors for external devices
According to the principle of work
1, chemical sensor
The use of chemical reaction principle, the chemical composition, concentration into electrical signals
Chemical sensors are made using chemical and chemical sensors. This sensor is generally through the ion-sensitive membrane to some of the chemical composition, content, concentration and other non-electricity into its corresponding amount of electricity. For example: different types of ion-sensitive electrodes, ion-sensitive FETs, humidity sensors and more. Biomedical chemicals measured with various chemical transducers are: K +, Na +, Ca2 +, Cl-, O2, CO2, NH3, H +, Li + and so on.
2, biosensors
Selective identification of bioactive substances to determine biochemical substances
Biosensors use sensors that contain a biologically active substance as a molecular recognition system. The sensor is generally used to catalyze a biochemical reaction or through a combination of specific, detection of macromolecular organic species and content, is the development of new sensors in the last half century. For example: enzyme sensors, microbial sensors, immune sensors, tissue sensors, DNA sensors.
3, physical sensor
Use of materials for physical changes
Physical sensors are sensors made from physical and physical effects. Belong to this type of sensor up to, for example, metal resistance strain sensor, semiconductor piezoresistive sensor, piezoelectric sensor, photoelectric sensor.
Various physical sensors detect the content
4, bio-electrode sensor
Body of a variety of bio-electricity, including: ECG, EEG, EMG, neuronal discharge
According to the bionic type of human organs points
Visual sensor
Including a variety of optical sensors and other sensors that can replace visual functions;
Hearing sensor
Including a variety of pickups, piezoelectric sensors, capacitive sensors and other sensors that can replace auditory functions;
Smell sensor
Including a variety of gas-sensitive sensors and curse him to replace the olfactory function of the sensor. This classification method is conducive to the development of biomimetic sensors. In addition to the wide range of common sensor classification methods cited, but also according to the sensor material, sensor structure, energy conversion fractional and other classification methods, have their own advantages and limitations. In addition to these conventional medical sensor devices, as wearable devices and IoT applications continue to innovate and evolve, new applications continue to be put into use or are on the verge of clinical trials in the medical field and in remote monitoring programs.
Nano-smart line monitoring of human function
Diagnosis of muscles and hip joints is often complicated and expensive. It is often too late to recognize the discomfort of these parts. The same is true for deep wounds and intraoperative incisions. There is a sensor that can be seamlessly implanted in the body and can receive real-time monitoring information in vitro. First it does not cause infection or immune response. At the same time, this sensor does not affect the normal functioning of the tissue after insertion, such as muscle stretch. Today's medical sensors are rigid, which makes them unable to monitor tissues such as the skin. But many organs and tissues are three-dimensional multi-layered biological structure. Monitoring these organizations requires a line of such sensors.
Suture the wound with thin liquid soaked with liquid
Nanomaterials can be either organic or inorganic, can be biologically active or inert, and can be designed as medical sensors with certain physicochemical properties, such as a variety of carbon nanotubes. Its conductivity is customizable, and as such, carbon nanotubes are emerging as the substrates of next-generation sensors and transistors. In addition, carbon nanotubes can monitor DNA and protein single molecules. Organic nano-polyaniline is also widely used, the most prominent feature is its conductivity depends on the environment pH.
Dip ordinary lids into liquids containing different nanomaterials and then quickly dry them. The properties of these threads depend on the properties of the nanomaterials in solution. Making flexible rubber fibers with carbon nanotubes and silicon coatings as sensing tips enables it to detect physical stresses. When this sensing lead is stretched, its conductivity changes, and we can detect this change outside the body.
When it is implanted in the body, it can be used to monitor wound healing and muscle strain. When an abnormal strain occurs, it means the wound is healing slowly or the device is not properly placed. This prompts doctors and patients to make the appropriate adjustments. It is an important basis to judge whether the wound is infected or not by detecting the tissue acidity by measuring the current intensity between two thread ends by coating one thread with carbon nanotubes and polyaniline nanofibers and the other with silver and silver chloride.
Glucose oxidase reacts with glucose to produce electrical signals, so glucose oxidase-coated sensing tips can monitor human blood glucose levels. By the same token, coating some of the other nanomaterials in the conductive head can also monitor the sodium and potassium levels in the blood, which are markers of blood metabolism.
Smart liners made using physico-chemical methods can transmit test information to emitters on the surface of the skin.
In addition to sensing capabilities, many materials have a useful feature at the thread end: wicking. It can use the capillary effect to divert the liquid, with the wick transport liquid wax to maintain the flame is a truth. Cotton threads transport the interstitial fluid to the sensing tips throughout the body. Sensing wire The electrical signal is transmitted to the surface of the skin with a button battery and a small elastic antenna device. The device amplifies and digitizes the signal and wirelessly transmits the signal to devices such as smartphones. In this way, the doctor can continuously monitor the patient's health status remotely.
This integrated wireless monitoring system has many advantages. First of all, patients are more free, no need to have hospitalization. Second, data collected in real time provides doctors with more accurate reference information. In addition, it reduces medical costs. Thread has a very wide range of applications. Diabetic patients have a difficult wound healing, which can lead to infection and even amputation. Stitching with a sensor wire allows doctors to spot problems early and react promptly to prevent their condition from deteriorating. Sensing thread can also be made of bandages, wound dressings and even hospital bed sheets, which can give warnings before they get out of control.
Wireless heart sensor
Heart failure is the most common cause of hospitalization in the elderly. How can patients with heart failure be well monitored at home? If we can monitor the patient's systolic, diastolic and mean pulmonary arterial pressure monitoring data, adjust the patient's treatment options, can reduce the hospitalization of heart failure patients. A wireless, implantable hemodynamic monitoring system for heart failure patients includes a sensor / monitor permanently implanted in the pulmonary artery, a transvenous catheter for transmitting and deploying sensors, an electronic system for acquiring and processing signals from the sensors , And transmit the pulmonary artery pressure measurements to a secure database. Following the procedure, patients wirelessly monitor their pulmonary artery pressure at home and the data is immediately transmitted to a secure database for physicians to monitor in real time through the website.
The results showed that the use of wireless implants for remote hemodynamic monitoring to guide the treatment of heart failure, can effectively reduce the chronic heart failure patients (CHF) after 18 months of heart failure hospitalization rate. Previous results showed that 6 months follow-up, pulmonary arterial pressure guide treatment group hospitalization rate of heart failure than the standard drug treatment group decreased by 30%. The 18-month follow-up found that hospitalization for heart failure with pulmonary arterial pressure was further reduced by 39% compared to the standard drug treatment group.
Woven socks temperature sensor
A smart sock that detects the health of people with diabetes can detect if the patient has inflammation through a temperature sensor. OFweek Sensor Network Recently, according to media reports, CES 2017 appeared on a smart socks to detect the health status of diabetic patients, it comes from the start-up enterprise Siren Care. The sock can detect if the patient has inflammation through a temperature sensor.
It is reported that type 1 and type 2 diabetes are most prone to foot swelling, if not detected in time, swelling will evolve into a more serious disease, causing foot infections in patients, and even need amputation. Therefore, the status of the foot monitoring can ensure the early prevention of various complications. The built-in sensor of this smart sock can play a key role in early detection.
Smart socks, although a wearable device, do not need to be recharged often. Each sock's built-in battery is fully charged for six months. Just put on socks, its built-in sensor will automatically start. Once the sock is taken off, the sensor will automatically shut down and enter sleep mode. In addition, the socks support machine washable, patients can wear for at least six months, all the data is stored in socks sensors, mobile App and cloud disk. When a foot injury occurs, the sock can detect a high temperature difference and then an alert will be given via the App to alert the patient that there is a problem with the foot.
Smart Fitness T-shirt built-in heart rate sensor and GPS positioning
This fitness data tracking device can be completed directly in the T-shirt fitness data tracking.
T-shirt sleeveless design, which is stitched inside the motion sensor, and is embedded in the fabric which is thin and unobtrusive. This means that athletes do not need to wear additional monitoring equipment, such as wristband devices or chest equipment. In addition, the T shirt also designed a small sensor, located in the collar.
The sensor also comes with GPS, which can be used to determine the speed, distance and acceleration of the athlete. In addition, the official also created a dedicated iPad application, real-time display of data, allowing trainers to track the performance of each athlete, and training programs to adjust as needed, effectively monitoring the workload during training camp.
A "thin film" sensor that detects cancer
A new bioelectrochemical detection chip, based on the polymer self-assembled membrane prepared by the biochemical electrochemical sensor, which will make the detection of cancer cells as simple as the blood glucose meter test, to provide the possibility of early cancer prevention.
At present, the commonly used methods of body fluid testing in major hospitals in China are immunoaffinity electrophoresis, which has high testing cost, strict equipment requirements and long testing time, so that a large number of patients lose the golden age of treating diseases. The thin film bioelectrochemical sensor to patients with early onset of blood will secrete a very small amount of monoclonal globulin and free light chain as an opportunity to identify the antibody grafted on the electrode surface of the polymer microporous membrane matrix, The unique identification, with the help of the electrochemical workstation, amplified into chemical signals, the successful implementation of the early detection of cancer cells function.
Perform clinical trials, from sample collection to injection, testing, and medical analysis, all in less than 10 minutes with low cost and accuracy. The technology and the hospital often used immunostaining electrophoresis method, the detection sensitivity increased by 500 times. Not only that, the technology supporting the cost of testing equipment is only 80,000 yuan, reducing test access, can be widely used. As a new platform for using biosensors, this technology can be applied to a wider range of technologies such as early diagnosis of severe diseases such as leukemia, uremia, lymphoma and liver cancer, and even more long-term developments in environmental monitoring and military exploration.
Sensors to detect diseases with respiration Medical sensors
Our breath contains a series of information about one's own health that exists in molecular form, its presence or absence and its concentration as a biomarker for disease detection, one that detects many different molecules and correlates these biomarkers with 17 Breathing sensor linked to disease.
Exhaled human body contains nitrogen, carbon dioxide and oxygen, as well as a small amount of more than 100 kinds of volatile chemical composition. The relative amount of these substances will vary according to human health. For example, diabetes will produce a trace of sweetness.
However, most current respiratory analyzers focus on a single type of disease and only detect a single marker, with limited scope of use and screening capabilities. Using mass spectrometry to identify respiratory components associated with the disease, the researchers found that each disease produces a unique volatile chemical signature based on 13 different components in varying amounts. They also found that the existence of a disease does not prevent the detection of other diseases, which is also a prerequisite for detecting and diagnosing various diseases in a non-invasive way.
This sensor consists of a series of specially prepared gold nanoparticle sensors, and a sensor based on a random network of single-walled carbon nanotubes. What's so special about it is that you can collect breath samples from thousands of patients with different diseases and find the correlation in the data using artificial intelligence software.
Thanks to the AI components under study, the system has an average diagnostic accuracy of 86% for 17 different diseases, including diseases such as cancer, Crohn's disease, two types of Parkinson's disease, preeclampsia and pulmonary hypertension . Before the modern medical experiment technology matures, doctors have diagnosed some diseases by looking at the patient's breathing and looking for disease clues. It now appears that this method of detecting diseases by breathing is more accurate by artificial intelligence.
Nanofluorescence sensor accurately excises tumor tissue
A new type of nanofluorescence sensor can specifically "open" and emit fluorescence in tumor tissue to help doctors accurately excise the tumor tissue and retain the normal tissue to the maximum extent.
According to the researchers, this groundbreaking technology is suitable for any type of tumor. Researchers inject this nanoparticle into the tumor tissue of a mouse, and once exposed to the tumor cells, the probe turns on and illuminates Tumor tissue. Human tumor tissue is acidic, the researchers have taken advantage of this feature of tumor tissue. For many tumors, surgery is the treatment of choice. However, it is still a huge challenge to completely remove the tumor tissue and retain the normal tissue as much as possible. Amotech can not accurately distinguish the tumor tissue from the non-tumor tissue because the current imaging technology is not sensitive enough.
The new technology uses clinically approved fluorescent dyes that can be imaged by standard cameras being used in hospitals around the world. This nano-probe acts like a sensor and opens and fluoresces only when the pH of the environment is below a threshold. The researchers conducted experiments in mouse models of head and neck cancer. They found that the use of this probe in surgery is extremely specific and sensitive, and it can even illuminate tumor nodules less than 1 mm in diameter. When performed, the probe accurately depicts the tumor's borders to the surgeon. This is a nano-scale switching technology, so far no single technology has such a high degree of accuracy. The preparation of such probes is relatively simple and therefore not costly, and this technique can be used to detect the border of tumors in the human body.
Magic sensor for brain cells glowing Medical sensors
For a long time, neuroscientists rely on electrical signals to record neuronal activity. Although this method can play a good detection effect, it can only be used for a small amount of neurons. And this new method can use optical technology, while recording the activities of hundreds of neurons. Optical recording methods generally use fluorescence, which requires a very strong external light source. The side effect of this is that it causes the living tissue to heat and direct some biological processes, especially those that are light-sensitive.
If they combine luminescence with optogenetics, they can create a new biological means of controlling cells in living tissues, especially neuronal cells, with light - a powerful new weapon for studying brain activity.
Researchers attach luminescent sensors to a virus that infects neurons and thus enters sensors inside neurons. Sounds pretty scary right? Researchers then chose calcium as a signal marker of neuronal activity. First, the sensor glows when it encounters calcium ions. Second, calcium is involved in the activation of neurons - the calcium content tends to be high in the environment outside of the neurons, but the intracellular content is low, but when the neurons are affected When stimuli from "neighbors (another neuron)", calcium levels briefly peak. The sensor responds to changes in calcium concentration by brightening and darkening - demonstrating that the sensor can equally detect a group of neurons.
Look at this picture, the neurons emitted by the sensor light, do not want a vast universe of dazzling stars? Originally there is a vast body of unsolved mysteries, I hope this legendary discovery can bring more human answers.
Sensors have always been an important player in the medical and health field because they are at the forefront of data collection. The development of peripheral technologies in the fields of sensors related to new materials, nanotechnology, biotechnology, power supply technology and new communication technologies has spawned a number of emerging medical and health products and service models centered on innovative sensor technology. New medical sensors with more sensitive, miniaturization, convenience, low cost, non-invasive or minimally invasive, the advantages of connectivity. It has made an indelible contribution to the progress and development of human medicine.
