## 1 Introduction
Manual implanters are known to have a higher HF survival rate compared to other simple transplantation methods that place HFs in punctures made using micro-blades or fine needles. Although the manual implanter is the most commonly used device in hair transplantation, it has a few fundamental problems, as shown in Figure 2. First, the long surgery time, caused by its structure, leads to much fatigue for both surgeons and patients. When the surgeon performs the transplant surgery, the nurse loads a HF in the needle of the manual implanter at the rate with which the surgeon transplants the HF. Second, musculoskeletal disorders are more likely to occur in surgeons due to the numerous simple repetitions of movements of the shoulder and wrist. This also relates to the longevity of the career of the surgeon. Third, a difference between the number of hairs transplanted per hour and  
Figure 1: Hair follicle (HF) extraction: (**a**) Strip harvesting, (**b**) follicular unit extraction (FUE), and (**c**) ARTAS. Transplantation methods: (**d**) Manual implanter (KNU implanter). HF engraftment rate may exist owing to varying surgical abilities of each surgeon. Fourth, the needle strength of the manual implanter is maintained for a specific patient. Consequently, the manual implanter is discarded after surgery without being reused. Since the needle is attached to the body of the manual implanter, the implanter cannot be reused even when only the needle is deformed. This results in higher surgical costs, in addition to continuous accumulation of other charges. On 10 May 2014, at the Korean Society of Hair Transplantation, a questionnaire was conducted on an automated hair transplantation device for a hair transplant clinician as shown in Figure 3. The total number of responses was 94, and 62% and 41% of respondents had clinical experience in hair transplantation for 3 years and 5 years or more, respectively. As a result of the survey, the proportion of respondents using manual implanter in the method of transplanting hair was 87.2%, the time for transplanting 3000 HFs was 4-5 h, and the intention to use an automated hair transplant device was 84%. Through the survey results, many doctors demand the need for an automated hair transplantation device, and if it is commercialized, it is judged that it will be able to create a sufficient market. In the current hair transplant surgery, a minimum of 2000 HFs are implanted in one patient. In each transplant, the surgeon executes a series of movements such as gripping, moving, aiming, transplanting, and in situ movement of a manual implanter. Repetition of these actions directly causes fatigue. Although several advanced devices for continuously extracting HFs, such as P-FUE and ARTAS, have been invented, devices for continuously transplanting HFs have not been developed yet. This is because the operation of the HF transplant is much more sophisticated and complicated than the HF extraction. To address the aforementioned problems, this study introduces a needle transportable semi-automatic implanter that can continuously transplant HFs without any replacement. The proposed implanter was designed to replace the repetitive motions of the surgeon when using the manual implanter with the replacement of a magazine equipped with multiple needles. Moreover, as the number of implant needles inserted into the magazine of proposed implanter increases, the surgical  
Figure 3: Survey on development of automated hair implanter; (a) hair transplantation method, (b) surgery time, and (c) willingness to use automated equipment. Figure 2: Problems of manual implanter. fatigue experienced by the surgeon and the patient, caused by the existing the manual implanter, decreases. In the proposed implanter, the needle part used in the manual implanter is independently present and, thus, disposable. Consequently, the cheap disposal cost of the needle can replace the expensive disposal cost of the manual planter.