Understanding Medical Devices: 20 Essential Basics

1. How to distinguish between drugs and medical devices containing drug components?

 

(1) For products where drugs play the main role and medical devices play an auxiliary role (such as pre-filled syringes, etc.), they are managed as drugs.

 

(2) For products where medical devices play the main role and drugs play an auxiliary role (such as drug-eluting stents, catheters with antibacterial coatings, medicated condoms, medicated intrauterine devices, etc.), they are managed as medical devices.

 

(3) Band-aids containing antibacterial and anti-inflammatory drugs are managed as drugs.

 

(4) Traditional Chinese medicine external application plasters are managed as drugs.

 

2. What management system does China implement for the production of medical devices?

 

China implements a product registration system for medical devices.

　　

The production of Class I medical devices is reviewed and approved by the drug supervision and administration department of the city-level people's government, and a product production registration certificate is issued.

　　

The production of Class II medical devices is reviewed and approved by the drug supervision and administration department of the provincial, autonomous region, or municipality directly under the Central Government, and a product production registration certificate is issued.

　　

The production of Class III medical devices is reviewed and approved by the State Drug Administration, and a product production registration certificate is issued.

 

3. What qualifications are required to operate medical devices?

　　

To establish a Class I medical device business, you should register with the drug supervision and administration department of the provincial, autonomous region, or municipality directly under the Central Government. To establish a Class II or Class III medical device business, you should be reviewed and approved by the drug supervision and administration department of the provincial, autonomous region, or municipality directly under the Central Government, and a Medical Device Business License will be issued.

　　

Without a Medical Device Business License, the Administration for Industry and Commerce shall not issue a business license.

 

4. What are the requirements for medical device advertising?

　　

Medical device advertisements must be reviewed and approved by the drug supervision and administration department of the provincial or higher level people's government; unapproved advertisements shall not be published, broadcast, distributed, or posted.

　　

The content of medical device advertisements should be based on the instructions for use approved by the State Drug Administration or the drug supervision and administration department of the provincial, autonomous region, or municipality directly under the Central Government.

 

5. Do medical devices need to undergo clinical trials before they can be marketed?

　　

Clinical trials of medical devices are divided into medical device clinical trials and medical device clinical verification.

　　

For medical devices that have not yet appeared on the market and whose safety and effectiveness need to be confirmed, clinical trials are required before approval for marketing.

　　

For medical devices of the same type that have already been marketed, and whose safety and effectiveness need further confirmation, clinical verification is required before approval for marketing.

 

6. What six certificates should be checked when purchasing medical devices?

　　

(1) Medical Device Manufacturing License (for Class II and III medical device manufacturers);

　　

(2) Medical Device Product Registration Certificate;

　　

(3) Medical Device Business License of the business operating the product (referring to businesses operating Class II and III products other than the thirteen Class II products);

　　

(4) Product Qualification Certificate;

　　

(5) 3C Certification Certificate (medical device equipment included in the Catalogue of Products Subject to Mandatory Product Certification should have a 3C certification certificate and mark);

　　

(6) EMC Certificate (referring to medical electrical equipment).

　　

7. What tricks should elderly consumers be aware of when purchasing medical devices from illegal operators?

　　

(1) Sweet words, providing "heart-to-heart" service to the elderly. Specifically, a large number of business representatives are sent out to make phone calls or distribute invitations in various public places such as parks and markets. They first get close to the elderly, then enthusiastically invite them to visit the company for free, and also provide free shuttle buses and free lunches. Along the way, they constantly persuade the elderly, making people feel it is difficult to refuse. Then they make a preferential offer that seems to be only available today, and if successful, the business representative will immediately follow the elderly home to collect money, only accepting cash and making various excuses for not issuing invoices.

　　

(2) "Gilding" the storefront, even openly claiming to be "legally approved" or a "nationally supported project." In order to deceive the elderly, illegal operators rent high-end office buildings in bustling city areas, boasting to the elderly about the strength of the operator, how they have been approved and supported by relevant national departments, and that a certain leader has personally guided them, etc., making them appear legitimate and trustworthy.

　　

(3) Novel selling points, using the so-called "green, environmentally friendly, healthy, and high-tech" slogans. They seize on the elderly's special psychological needs for health, distributing exquisite promotional materials, and falsely exaggerating products that do not have the necessary functions into "panaceas" that can "cure all diseases".

 

8. What points should be considered when purchasing medical devices?

　　

When purchasing medical devices, pay attention to the following points: First, it should be personalized and appropriate for the time. According to your own situation, consider whether your physical condition (or illness) requires a medical device? Is it more appropriate to use medicine or a device? Is this product suitable for your physical condition (or illness)? Is the performance-to-Price ratio reasonable? Combine your actual situation to prioritize these questions, so you will have a clearer understanding of whether the product you want to purchase is what you need. Second, when purchasing medical devices, you should purchase them from units with a medical device production license or medical device business license (the products they produce or operate should be within the scope of the license). Third, do not blindly believe in advertising, and be discerning about the results of "free clinics," the efficacy of medical devices "recommended on the spot," and various "free health lectures." When you are not sure whether you need a certain product, you should consult a doctor, and do not blindly purchase.

 

9. What items are included in the contents of the medical device instructions?

　　

Medical device instructions generally should include the following: Product Name, Model, Specification; Manufacturer Name, Registered Address, Production Address, Contact Information and After-sale Service Unit;《Medical Device Manufacturing License》Number (except for Class I medical devices), Medical Device Registration Certificate Number; Product Standard Number; Product performance, main structure, scope of application; Contraindications, precautions and other warnings or prompts; Explanation of graphics, symbols, and abbreviations used on the medical device label; Installation and use instructions or diagrams; Product maintenance and maintenance methods, special storage conditions, methods; For products with a limited shelf life, the expiration date should be indicated; Other contents that should be indicated in the instructions as stipulated in the product standard.

 

10. What content should not be included in the medical device instructions?

　　

Medical device instructions shall not contain the following content: Assertions or guarantees of efficacy such as "best efficacy", "guaranteed cure", "guaranteed treatment", "radical cure", "immediate effect", "completely without side effects"; Absolute language and expressions such as "highest technology", "most scientific", "most advanced", "best"; Description of cure rate or effective rate; Comparison with the efficacy and safety of other companies' products; Commitment language such as "insurance company insurance", "refund if ineffective"; Using the name or image of any unit or individual for proof or recommendation; Statements that make people feel that they have already suffered from a certain disease, or that mislead people into thinking that not using the medical device will cause a certain disease or aggravate the condition; Other contents prohibited by laws and regulations.

 

11. What are the disposable sterile medical devices?

　　

Disposable sterile syringes, disposable infusion sets,

　　

Disposable blood transfusion sets, disposable burette infusion sets, disposable sterile injection needles, disposable intravenous infusion needles, disposable plastic blood bags, disposable blood collection devices.

　　

How should disposable sterile medical devices be handled after use?

　　

Used disposable sterile medical devices must be destroyed after being deformed, so that their components no longer have the function of use, and disinfected and harmlessly treated.

　　

Can disposable sterile medical devices be reused?

　　

Disposable sterile medical devices cannot be reused.

 

12. From a clinical perspective, how can instrument and equipment medical devices be categorized?

　　

(1) Large equipment, such as: CT, MRI, PET/CT, DSA.

　　

(2) Inspection and analysis equipment, such as: biochemical analyzer, blood cell counter, binocular biological microscope, urine analyzer, enzyme labeling instrument, plate washer, biological safety cabinet, ultra-clean workbench.

　　

(3) Diagnostic equipment, such as: ultrasound diagnostic instrument, various X-ray machines, electrocardiograph.

　　

(4) Critical care equipment, such as: ventilator, anesthesia machine, monitor.

 

13. How to rationally purchase a blood glucose meter?

　　

As a lifelong disease, diabetes requires monitoring and controlling blood glucose as the primary task for patients. It is very important to know your blood glucose level in time. In addition, any measures taken by diabetic patients to control blood glucose, such as medication, dietary control, and the use of insulin, must be understood through blood glucose testing to be well-informed. Some patients use urine sugar test strips, which are relatively inexpensive, but urine sugar test strips cannot reflect hypoglycemia. Therefore, it is very necessary for patients to have a blood glucose meter at home.

　　

When purchasing a blood glucose meter, the following aspects must be noted: Choose a blood glucose meter with good after-sales service and guaranteed long-term supply of test strips; The test strips of different brands of blood glucose meters are different and cannot be used interchangeably. Test strips should be easy to purchase and individually packaged; easy to operate. When purchasing, ask the salesperson to demonstrate and confirm that you can operate it independently. It is best to have no buttons for simpler operation. The numbers displayed on the blood glucose meter's display screen should be easy to identify. It is best to use a blood glucose meter that can report the measured value by voice. The blood glucose meter should preferably have a "memory" function to store your measured blood glucose values.

 

14. What types of blood glucose meters are there?

　　

Since its invention by Tom Clemens in 1968, the blood glucose meter has undergone different stages of technological development, and different types of blood glucose meters have emerged, such as portable blood glucose meters, dynamic blood glucose meters, and table-type blood glucose meters. Currently, most of our diabetic patients purchase portable blood glucose meters.

　　

Blood glucose meters can be divided into two types according to their working principles: one is the electrode type and the other is the photoelectric type. The testing principle of the electrode type is more scientific. The electrode is hidden in the mouth to avoid contamination, and the blood sample does not directly contact the machine. The error range is within ±0.2, with high accuracy. Under normal use, it does not need to be calibrated and has a long lifespan. The photoelectric blood glucose meter is similar to a CD player, with the detection head exposed and the blood sample inside. It is easy to contaminate, affecting the test results. The error range is larger, generally more accurate in the short term, and needs to be calibrated at a repair station after using it for some time.

　　

Blood glucose meters are divided into two types according to the blood sampling method: one is the blood sucking type and the other is the blood smearing type. For blood-sucking blood glucose meters, the test strip itself controls the blood sample measurement. It will not cause deviations in the results due to the amount of blood, and the operation is convenient. Just use the test strip to touch the blood drop. Blood smearing machines generally have a larger blood sampling volume, causing more pain to the patient. If the blood sampling is excessive, it will also affect the test results. Insufficient blood volume will result in operational failure and waste of test strips. The latest blood glucose meters have adopted the electrode principle and blood-sucking blood sampling.

 

15. What is the working principle of a CT machine?

　　

Different human tissues (including normal and abnormal tissues) absorb X-rays to varying degrees. Computed tomography (CT) utilizes this characteristic, dividing a selected layer of the human body into many cubic small blocks called voxels. X-rays pass through the human body to measure the density or grayscale of each voxel, which is the basic unit on the CT image, called a pixel. They are arranged in a rectangular array to form an image matrix. When the X-ray tube emits an X-ray beam from one direction through the selected layer, each voxel arranged along that direction absorbs a certain amount of X-rays, causing the X-rays to attenuate. When the X-ray beam penetrates the tissue layer (including many voxels) and is received by the opposite detector, the amount of X-rays has been attenuated significantly; this is the sum of the X-ray attenuation values of all voxels in that direction. Then, the X-ray tube rotates a certain angle and emits an X-ray beam in another direction. The detector on the opposite side can measure the sum of the X-ray attenuation values of all voxels along the second irradiation direction. By repeating this method many times in different directions to scan the selected layer of tissue, several sums of X-ray attenuation values can be obtained. In the above process, each scan yields one equation. In this equation, the total amount of X-ray attenuation is a known value, while the X-ray attenuation values of the voxels that form this total are unknown values. After several scans, a system of equations is obtained, and the computer calculation can solve this system of equations to obtain the X-ray attenuation value of each voxel. Then, through number/analog conversion, the different attenuation values of the voxels form the different gray levels of the corresponding pixels, and the matrix image formed by the pixels is a black and white image of tissues with different densities at that layer.

 

16. What should be noted when undergoing a CT scan?

　　

(1) For abdominal, pelvic, and enhanced CT scans, fasting and no water intake are required 4-6 hours beforehand to avoid artifacts and affect the CT image quality. For CT scans of other parts of the body, fasting and no water intake are not necessary.

　　

(2) Because contrast agents can cause allergic reactions, an allergy test is needed beforehand.

　　

(3) During the examination, the supine position is generally adopted; the prone position or other positions are used as needed. To ensure accurate positioning, do not move during the examination and cooperate with the staff.

 

17. What are the advantages of spiral CT?

　　

Spiral CT is one of the most advanced CT devices in the world. It features fast scanning speed, high resolution, and superior image quality. Using fast spiral scanning, one part of the body can be examined in about 15 seconds, and lesions smaller than a few millimeters, such as small hepatocellular carcinoma, pituitary microadenomas, and small aneurysms, can be detected. It has comprehensive functions, can perform examinations of all parts of the body, and can perform various three-dimensional imaging, such as multi-planar reconstruction, CT angiography, organ surface reconstruction, and simulated endoscopy of the intestines, trachea, and blood vessels. Real-time lens-guided CT-guided puncture biopsy can be performed, which is quick, convenient, and accurate.

 

18. What are the advantages of magnetic resonance imaging?

　　

The images obtained by magnetic resonance imaging are exceptionally clear, detailed, have high resolution, good contrast, and large amounts of information, especially for soft tissue. It allows doctors to see internal tissues clearly, significantly improving diagnostic efficiency. It avoids many craniotomies, thoracotomies, laparotomies, and other exploratory diagnostic surgeries that were previously unavoidable due to unclear pre-operative diagnoses, sparing patients from unnecessary surgical pain and complications. Therefore, it has been widely welcomed by imaging professionals and clinicians since its introduction, and it is now commonly used clinically, becoming an indispensable examination method for the diagnosis of some diseases.

　

19. Are CT and MRI always superior to ultrasound?

　　

No. As an important part of imaging diagnostic techniques, ultrasound diagnostic technology has many advantages over CT and MRI.

　　

First, it can not only detect lesions in abdominal organs but also continuously and dynamically observe the movement and function of organs. It can track lesions, display three-dimensional changes, and is not limited by its imaging layering. For example, ultrasound examination is currently considered the preferred method for biliary tract diseases.

　　

Second, in addition to solid organs (liver, pancreas, spleen, kidney, etc.), B-ultrasound can also combine Doppler technology to monitor blood flow and direction, thus distinguishing the nature and degree of organ damage. For example, doctors can visually see various structures inside the heart and whether there are abnormalities through cardiac ultrasound.

　　

Third, ultrasound equipment is easy to move, non-invasive, and can be used for diagnosis at the bedside for patients with limited mobility.

　　

Fourth, the Price is low. The cost of ultrasound examination is generally 35-150 yuan/time, which is 1/10 of CT examination and 1/30 of MRI. This is relatively affordable for most salaried workers. Therefore, "B-ultrasound" is often used for health checkups. But does this mean that "B-ultrasound" is superior to CT and MRI in all aspects? No. For example, B-ultrasound is significantly inferior to the latter in terms of clarity and resolution, and it is easy to miss lesions in hollow organs, and the results are also easily affected by the clinical skills of the physician.

 

20. How to choose an electrocardiogram examination?

　　

Electrocardiography (ECG) is the most commonly used method for examining heart disease clinically. However, ECG examinations have limitations; not all heart diseases can be diagnosed with ordinary ECGs. Ordinary ECGs are what we usually refer to as ECGs. It only shows the voltage changes and excitation propagation during cardiac activity, but it cannot determine the source of heart disease and is not easy to detect transient arrhythmias and myocardial ischemia.

    

Therefore, it is only suitable for examining persistent or frequently occurring ECG abnormalities, especially for the diagnosis of cardiac emergencies. Exercise ECG is an ECG examination performed after giving the patient a certain amount of exercise load (such as climbing stairs, cycling, treadmill exercise). It is a method to examine the function of coronary arteries and is very helpful in diagnosing coronary heart disease and understanding cardiac reserve capacity.

　　

Dynamic ECG is a method of continuously recording dynamic cardiac activity for a long time (24 hours or more). It can fully reflect the symptoms and changes in the heart that appear in the subject during activity and sleep. It is suitable for examining transient arrhythmias and myocardial ischemia, and can qualitatively and quantitatively diagnose arrhythmias and understand the cardiac reserve capacity. However, its disadvantage is that the report is delayed and it cannot be used for cardiac emergencies. Echocardiography is a method that uses ultrasound to examine the morphology of the heart. It is mainly used for the examination and diagnosis of valvular heart disease, pericardial effusion, hypertrophic cardiomyopathy, and congenital heart disease.