TECHNICAL FIELD

The present invention relates to an evaluation apparatus and an evaluation method for evaluating hair loss based on a hair image.

BACKGROUND ART

Female pattern hair loss (FPHL) is diffuse alopecia that occurs mainly in women. As FPHL pattern classification, Ludwig presented the three-stage classification in 1977 into (see Non-Patent Literature 1), and Olsen presented the Christmastree pattern in 1999 (see Non-Patent Literature 2). With these pattern classifications, the shape of FPHL that has advanced to some extent can be evaluated, but the classifications are based on the size of exposed scalp that is only observed in an advanced stage, and are not useful for evaluating early female pattern hair loss (early FPHL). Early FPHL means a condition of being mild in FPHL, and Olsen expressed the feature as “a slightly opened partline” (see Non-Patent Literature 3).

On the other hand, Sinclair et al. considered early FPHL, that is the feature of appearance in a condition of being mildest, as “no change in a partline” (see Non-Patent Literature 5). As described, early FPHL has various symptoms in a condition of being mild, and the definition of “early” in FPHL varies depending on experts. Thus, although early FPHL has various symptoms in a condition of being mild, all the early FPHL types are classified as one type.

There has been no evaluation method for finely classifying various symptoms in early FPHL. Although there is a therapeutic effect evaluation for FPHL using a photograph of a whole of the hair (global photograph: GP), the seven-point scale has been mainly used. In the seven-point scale, a GP before treatment is set as a base line, and the impression of change from the base line is evaluated as one of seven stages (−3=significantly reduced, −2=fairly reduced, −1=slightly reduced, 0=unchanged, +1=slightly improved, +2=fairly improved, +3=significantly improved). However, the evaluation between a patient and a medical doctor/researcher does not necessarily match (see Non-Patent Literature 6).

In daily medical examination, GPs have been used as a method for the classifying the severity and determining the therapeutic effect in male pattern hair loss. In FPHL, Olsen referred to GPs as an evaluation item that is the most important and has the credibility in the FPHL clinical study. However, early FPHL patients rarely have opened partlines or scalp seen through hair, and it is difficult to evaluate the degree with GPs using the existing FPHL classification. This is one of unsolved problems in treatment for early FPHL.

CITATION LIST

Non-Patent Literature

Non-Patent Literature 1: Ludwig E. Classification of the types of androgenetic alopecia (common baldness) occurring in the female sex. Br J Dermatol. 1977 September; 97(3): 247-54Non-Patent Literature 2: Olsen E A. The midline part: an important physical clue to the clinical diagnosis of androgenetic alopecia in women. J Am Acad Dermatol. 1999 January; 40 (1): 106-9Non-Patent Literature 3: Olsen E A. Female pattern hair loss J Am Acad Dermatol 2001 September; 45 (3 Suppl): S70-80Non-Patent Literature 4: Harries M, Tosti A, Bergfeld W, Blume-Peytavi U, ShapiroJ, Lutz G, Messenger A, Sinclair R, Paus R. Towards a consensus on how to diagnose and quantify female pattern hair loss—The ‘Female Pattern Hair Loss Severity Index (FPHL-SI)’. J Eur Acad Dermatol Venereol. 2016 April; 30 (4): 667-76Non-Patent Literature 5: Biondo S, Goble D, Sinclair R. Women who present with female pattern hair loss tend to underestimate the severity of their hair loss. Br J Dermatol. 2004 April; 150(4):750-2.Non-Patent Literature 6: Blume-Peytavi Ul, Hillmann K, Dietz E, Canfield D, Garcia Bartels N. A randomized, single-blind trial of 5% minoxidil foam once daily versus 2% minoxidil solution twice daily in the treatment of androgenetic alopecia in women. J Am Acad Dermatol. 2011 December; 65 (6): 1126-1134

SUMMARY OF INVENTION

Technical Problem

Thus, one of problems of early FPHL is how to objectively evaluate the degree of hair loss (decrease in the hair volume of the head) of which a patient is aware and to determine the therapeutic effect (see Non-Patent Literature 4). Since a patient in early FPHL has more chances to recover with appropriate therapeutic intervention than in FPHL that has advanced, to start treatment in an early FPHL stage has significance in increasing the therapeutic effect and in reducing the emotional and financial burdens on the patient. For this reason, it is required to provide an evaluation method capable of categorizing early FPHL having various symptoms despite a mild degree, finely classifying progression, and determining the therapeutic effect.

Solution to Problem

A head-image evaluation apparatus according to the present embodiment includes an acquiring unit that acquires a head image obtained by photographing the hair of a subject, a recognizing unit that recognizes, from a reflection image in which surface-reflected light in the head image is formed, the shape of the surface-reflected light, and a categorizing unit that determines a distortion degree of the shape of the surface-reflected light in the reflection image with image processing, and categorizes the distortion degree as one of a plurality of stages.

Advantageous Effects of Invention

In the present embodiment, by evaluating the degree of hair loss or determining the therapeutic effect with GPs, it is possible to obtain a beneficial result for both a medical practitioner and a patient to decide a treatment policy in early hair loss represented by early FPHL. With the present embodiment, it is possible to establish suitable progression classification for early hair loss represented by early FPHL and to determine the therapeutic effect. Thus, it is possible to increase chances to recover with appropriate therapeutic intervention, and to treat hair loss in an early stage, which has been desired.

By setting evaluation criteria based on the shape of surface-reflected light, it is possible to evaluate treatment progress with GPs even in early FPHL that is difficult to evaluate objectively. The evaluation method using GPs according to the present embodiment is easily utilized by medical practitioners and helps patients to easily understand the progress, and is useful as an evaluation method for an early stage of hair loss, such as early FPHL.

With a GP evaluation method according to the present embodiment, patients easily understand fine gradual change in an early FPHL stage. With the GP evaluation method according to the present embodiment, it is possible to grasp a sign of change in the hair before an obvious change occurs. In FPHL, factors that affect the change in the hair cycle that is the FPHL disease mechanism are complicated, the process is not uniform, and remission or aggravation can happen. By detecting a sign of change in an early stage using the GP evaluation method according to the present embodiment, a treatment policy is easily decided, which helps treatment for hair loss, such as mainly early FPHL.

