Various hair implantation procedures and equipment associated with the implementation thereof have been employed in the prior art. Follicular unit hair transplantation is the procedure most commonly used. This procedure is however invasive since it involves removal of a strip of the scalp from a donor area and placement of the graft at a recipient area. Such strip removal necessitates shaving and leaves a scar that is difficult to heal, thereby posing restrictions in the client's normal activities over a rather long healing period. The process is rather slow with short daily sessions enabling implantation of a limited number of hair of the order of 500 units, whilst its efficiency is rather low due to a large percentage of up to 20% of follicles being damaged during the removal of the strip and the subsequent division thereof in individual follicles to be implanted into the recipient zone. Eventually since a number of sessions must take place to perform the overall hair transplantation process and since such sessions have to be scheduled with extensively long intervals in between, it becomes uncomfortably long to complete the process. Furthermore, placement of hair follicles is subsequently performed by means of forceps thereby leaving much room for human error that often leads to oddly directioned hair at incorrect angles instead of the desired natural result of evenly angled hair. Moreover such graft extraction and subsequent implanting process is not available for all clients, e.g. very curly hair cannot be extracted, and a preliminary test has to be conducted to determine whether the process is suitable for each particular candidate.
The object of the present invention is to overcome and eliminate the abovementioned disadvantages and drawbacks of the prior art. With this scope in mind, the invention proposes a minimally invasive hair transplantation process that is available to all potential candidates without exception and requires neither shaving of the scalp nor removal of grafts or any preliminary testing whatsoever. Instead single hair follicles are extracted from a donor region to be subsequently implanted at a recipient region. The process is fast providing the possibility of an approximate number of 5,000 hair units being extracted in one session.
The object of the invention is further to disclose preferred specialized tools for the implementation of the abovementioned direct hair implantation process and in particular to propose alternative embodiments of tool devices as follows:                a. a hair harvesting device adapted to perform cutting of individual hair follicles comprising a tubular cutting head with a conical knife edge cutting surface formed at one end thereof or with conical knife edge cutting surfaces of different diameters formed at two ends thereof.        b. a hair harvesting device comprising a cross like pattern of tubular cutting heads, each one being formed with a conical knife edge cutting surface of different diameter allowing removal of follicular hair units of varying diameters with a single harvesting instrument.        c. a hair implanting device comprising a hollow needle having a longitudinal groove at a frontal portion thereof with an obliquely cut free end adapted to receive a follicular hair unit, a sliding rod being reciprocatingly movable axially along the needle to effect placement of the follicular hair unit disposed within the groove of the frontal end of the needle within a predetermined position of the scalp at the recipient bald area, and a tubular housing adapted to receive said needle and said sliding rod incorporating means of performing the hair implanting operation.        
It is a further object of the invention to provide the aforementioned hair implanting device with means of appropriately regulating and fine adjustment of the depth of intrusion of the needle into the scalp to provide for optimum performance of the hair implanting device.
Another object of the invention is to disclose an electrically operated mode of the hair transplanting device.
A final object of the invention, in view of accelerating the hair transplantation process by avoiding the step of the tiresome exchange of instruments, is to provide a combined hair harvesting and hair implanting device operated preferably manually when effecting hair harvesting and preferably electrically when effecting hair implantation, wherein the aforementioned knife edge cutting surface of the hair harvesting device is obliquely cut so as to be adapted to perform the combined role of the follicular hair unit receiving groove of the hair implanting device.