The Prosecutor’s appeal against Defendant B and C and the Defendants’ appeal are all dismissed.

1. Summary of grounds for appeal;

A. The Prosecutor’s sentence against Defendant B and C (each suspended sentence, each suspended sentence: fine of KRW 1,00,000) of the lower court is too unhued and unreasonable.

B. In the instant case, the Defendants’ act of investigating the light power of the Defendants using the low-power light source inspector to the patients does not constitute medical practice.

In addition, the defendant B and C merely operated the above machinery according to the direction of the defendant A, and therefore, they did not directly assist the defendant A's medical practice.

However, the lower court, which found the Defendants guilty of all the charges, erred by misapprehending the legal principles as to medical practice, thereby adversely affecting the conclusion of the judgment.

2. Determination

A. In determining whether a certain act of the Defendants’ assertion of misunderstanding the facts and misapprehension of the legal doctrine constitutes medical practice, the issue is not whether the equipment used for the prevention and treatment of a disease is a medical device, and whether a person with no medical expertise is likely to cause danger to human life, body, or public health by using it for the prevention and treatment of a disease.

In principle, such medical practice can be performed only by a medical person. However, it is permitted for a person who has a license for a clinical path, radiation doctor, physical therapy, occupational technician, dental technician, dental technician, or dental technician to engage in medical treatment or medical examination under the instruction of the “medical doctor or dentist” under the Medical Technicians Act. However, allowing a person to engage in part of medical practice within the limited scope of medical technician system under the Medical Technicians, etc. Act, among the medical practice limited only for medical personnel, the human life, body, or public health should be terminated by the human body.