Cohen Bernard
Department of Dermatology and Cutaneous Surgery, University of Miami, Miller School of Medicine, Coral Gables, Florida 33145, USA.
Dermatol Surg. 2008 Jul;34(7):900-10; discussion 910-1. doi: 10.1111/j.1524-4725.2008.34175.x.
Office physicians are unable to measure hair quantity, hair loss, and hair growth in a simple and meaningful manner. One solution is to measure the cross-sectional area of a bundle of hair that is growing within a premeasured cross-section of scalp.
The objective was to design a mechanical device that precisely measures the cross-sectional area of a bundle of hair and design a device that can precisely delineate an area of scalp. It was assumed that density and diameter changes are evidenced by changes in the bundle cross-sectional area and that growth and loss are the result of density and diameter changes. These assumptions were confirmed using various sized bundles of known diameter non-hair filaments.
Bundles of hair and surgical silk fibers were tested using a mechanical device that compressed the bundle and measured its cross-sectional area. Balding patients were categorized according to their observed severity of the loss. Bundles of their uncut hair from 4-cm(2) scalp sites were measured and the values were compared to the patient's category of hair loss severity.
In patients with balding, there was a direct correlation between the bundle's cross-sectional area and the observed severity of the loss. The cross-sectional area was expressed as square millimeters of hair per square centimeter of skin x 100 (mm(2)/cm(2)x 100) and named the trichometric index (TI). Using surgical silk fibers, there was a direct correlation between the bundle's cross-sectional area and the number of filaments, the diameter of the filaments, and the dry weight of the filament bundle. Using aggregates of cut human hair, there was a direct correlation between the cross-sectional area and the dry weight of the bundle.
This prototype device shows promise as a diagnostic instrument for measuring changes in hair quantity (mass), hair diameter, and hair density, as evidenced by preliminary studies using silk sutures, cut human hair, and patients with various degrees of balding. Formal clinical studies are needed. Although the device itself showed a high degree of precision, the accuracy and reproducibility of the measurements can be compromised if the sampling method is not carefully performed using magnification. The device is intended for use on uncut hair that is more than 1 inch in length.
门诊医生无法以简单且有意义的方式测量头发数量、脱发情况和头发生长情况。一种解决方案是测量在预先测量的头皮横截面上生长的一束头发的横截面积。
目的是设计一种能精确测量一束头发横截面积的机械设备，并设计一种能精确划定头皮区域的设备。假定密度和直径的变化可通过发束横截面积的变化体现出来，且生长和脱发是密度与直径变化的结果。使用各种已知直径的非毛发细丝束对这些假设进行了验证。
使用一种压缩发束并测量其横截面积的机械设备对发束和手术丝线纤维进行测试。根据观察到的脱发严重程度对秃顶患者进行分类。测量了他们从4平方厘米头皮部位采集的未剪头发束，并将测量值与患者的脱发严重程度分类进行比较。
在秃顶患者中，发束的横截面积与观察到的脱发严重程度之间存在直接关联。横截面积表示为每平方厘米皮肤的头发平方毫米数×100（mm²/cm²×100），并命名为毛发测量指数（TI）。使用手术丝线纤维时，发束的横截面积与细丝数量、细丝直径以及细丝束的干重之间存在直接关联。使用剪下的人发聚集体时，横截面积与发束的干重之间存在直接关联。
通过使用丝线缝合线、剪下的人发以及不同程度秃顶患者进行的初步研究表明，这种原型设备有望成为一种用于测量头发数量（质量）、头发直径和头发密度变化的诊断工具。需要进行正式的临床研究。尽管该设备本身显示出高度的精确性，但如果不使用放大设备仔细进行采样方法，测量的准确性和可重复性可能会受到影响。该设备适用于长度超过1英寸的未剪头发。
