HK1098031B - Method, device and cartridge for measuring fluctuations in the cross-sectional area of hair in a pre-determined scalp area - Google Patents

Description

Method, device and cartridge for measuring changes in the cross-sectional area of hair in a pre-designated scalp area

Background of the invention

1. Field of the invention

The present invention relates to a method, device and two-piece cartridge (cartridge) for measuring the change in the cross-sectional area of a bundle of hair, with the aim of recording the clinical course of the medical hair loss disorder and the effect of the hair growth treatment and/or indirectly calculating the severity of the balding disorder or the efficacy of the hair growth treatment using the number of hairs and/or the increase or decrease in the axial diameter of the hairs as evidence.

2. Description of the related Art

Heretofore, a hair volume-measuring device (hair volume-measuring device) for measuring the degree of damage to hair has been disclosed in U.S. patent No. 4,665,741 to Kabacoff et al.

See also, e.g., in j.am.acad.dermatology, 2003; 48: 253-62 "New and old method for evaluating the efficacy of hair growth promoter in pattern hair loss".

Hair cutting is a condition characterized by the removal of hair of normal size diameter. It is one of two major alopecia (hair loss) types. Temporary hair loss is widely distributed on various parts of the scalp and can be a sign of a variety of medical abnormalities and toxicities. It may occur physiologically after high fever, withdrawal of birth control drugs, or childbirth. Temporary hair loss is characterized by the emergence of the scalp where hair has once grown. The extent of temporary hair loss can be quantified by measuring the hair density over a square centimeter area of the scalp. Measurement of hair density typically requires trimming the hair near the scalp (approximately 2mm long, 5mm x 5mm area), then counting the number of trimmed hairs remaining on the scalp and multiplying this value by 4. In the absence of temporary hair loss, normal human hair density ranges from 120 to 200 hairs per square centimeter of area on the scalp.

Hair thinning (hair thinning) is a condition characterized by gradual hair loss in individual areas of the scalp. It is the second major type of hair loss, and is more common. The appearance of hair loss results from the eventual loss of hair due to the reduction in diameter. Thinning (like temporary hair loss) is also characterized by the appearance of the scalp in the area where hair has once grown. Hair thinning affects approximately 75% of men and 10% of women. Unlike temporary hair loss, hair thinning is not distributed over the entire scalp surface, but almost always occurs as hair loss at the top of the head. Thinning characteristically occurs rarely behind and to the sides of the lower scalp (see area 10 depicted in fig. 19), thus forming the familiar horseshoe-type border that also exists in most previous cases.

Thinning occurs in healthy individuals and is commonly referred to as baldness, pattern baldness, male or female pattern baldness, androgenic alopecia (androgenic alopecia), male or female pattern baldness. It is believed that baldness occurs in approximately 75% of the male population. Also, although this baldness may also occur in healthy women, it may indicate endocrine dysregulation in a small portion of the female population.

Early pattern baldness is difficult to identify and difficult to quantify. Simple density measurements (as used in temporary hair loss) are of little value because the measurement is a mixed quantity of both normal size and thinned hair. When density counting is performed, a normal and thinned hair will be treated as a hair, respectively. Therefore, in order to detect and quantify thinning in a meaningful way, the actual total amount of hair (the total cross-sectional area of hair for a pre-designated scalp area) must be measured. This value alone reflects the distribution of density and blend diameter of the hair.

In order to quantify pattern and diffuse hair loss, scientists generally use the following three basic methods:

1. hair Density count or target area Hair count

2. Clinical photography

3. Weight of hair

Quantitative determination of hair loss by measuring the total cross-sectional area of hair in a pre-designated scalp area has not been reported in the scientific literature nor disclosed in prior U.S. patents.

A more detailed description of the three general approaches described above follows:

density count or target area hair count. The density of the cut hair in an area of the scalp is compared to a known normal range of values, where the normal range is 150 to 250 hairs per square centimeter of area. To determine whether a hair growth product is effective, it should be evaluated before and after treatment, respectively. To determine the percent loss of hair density for a single individual, the hair density at the top of the scalp (bald area) was compared to the hair density at the lower back and on both sides (normal permanent hair area). The percentage of hair loss is calculated as the number of hairs in the area of loss divided by the number of hairs in the permanent area.

This method is very inaccurate in measurement results for thinning because it only counts the number of hairs, regardless of the change in hair diameter. This method is used in a simple office setting because it is more accurate than the method of clinical photography. It requires careful hair trimming and direct examination of the scalp test area using a hand-held magnifying glass or video microscope. The measurement accuracy of the method can be improved if a macro photograph of a designated area of the scalp is taken and magnified and then only hairs above a certain diameter (typically 40 microns) are counted in the photograph.

Clinical photography: a photograph was taken to compare the area of hair loss and permanent hair area of the patient. It is also possible to compare the area of hair loss of a patient with a photograph of the same area of a patient without hair loss, or to compare photographs of the condition of the same patient before or after hair loss. To determine whether a hair growth product is effective, it should be evaluated before and after treatment, respectively. In this test method, the growth or loss of hair is only roughly quantified by visual observation alone. It is not possible to distinguish whether the hair loss is due to thinning or temporary hair loss. Photogrammetry results in considerable inaccuracies and ambiguity due to differences in hairstyle and hair length. However, this method is the most commonly used form of hair loss recording because it is rapid, does not require special training of the test personnel and is easy to operate. To obtain a variety of comparable data, it requires cutting the hair to a consistent length, illuminating with standard photographic equipment, and carefully selecting the exact location of the test object.

Hair weight: a smaller hair area (typically 5mm x 5mm) is shaved in the bald area. The patient returns 30 days later and the newly grown hair is then cut and weighed. To determine whether a hair growth product is effective, it should be evaluated before and after treatment, respectively. For pattern baldness, the test can be performed on permanent hair areas (lower back of head and horseshoe shaped areas on the sides) and the test results compared to the values for thinning areas of the same patient. Percent hair loss was calculated as the hair weight in the thin hair zone divided by the hair weight in the permanent zone. Hair weight is the precise method of measuring hair loss because this method of measurement takes into account both the number of hairs and the diameter of the hairs, as well as the length of the hairs in the calculation. It has the disadvantage that the sample size represents only a relatively small sample of the scalp surface, but because it also measures hair length, it may not be as meaningful as might be imagined.

Furthermore, this testing procedure is cumbersome, requires extremely stringent humidity control, and is poorly operable clinically. While it requires trimming of the hair. This test method is mainly used in commercial laboratories to test the effect of hair growth formulations, namely finasteride, dutasteride and minoxidil.

Summary of The Invention

The present invention provides a method and apparatus for measuring the change in cross-sectional area of a portion of hair, which method and apparatus relate to quantifying the clinical course of a medical hair loss disorder, or the effect or progress of treating hair loss. The method and apparatus are used to determine the total cross-sectional area of hair in a pre-measured area. The method and apparatus are used to measure samples of larger scalp surface than those tested in the hair weight test method, hair count method, and do not require hair trimming. The length of the hair is not a consideration in the evaluation, as the different individual hair styles make it unrealistic and not clinically relevant. The method of the present invention is easy to operate without a laboratory setting and uses a novel handheld device. The method and apparatus allows physicians and hair care professionals to track and record the condition of patients suffering from thinning or hair loss at any time during their evaluation and treatment. The method and device can be used for quantitatively evaluating the treatment effect of hair growth promoting preparation and medicine, and quantitatively determining the severity and clinical course of other medical alopecia diseases. The method and apparatus may also be used to detect early reductions in hair diameter many years before baldness occurs-which is a predictive sign of baldness.

In practicing the method of the present invention, a pre-designated area of the scalp where hair is growing may be isolated in any of several ways. Typically, a 2 x 2cm scalp area is manually isolated with a comb or hair combing element and secured with 1 x 3 "gummed paper printed with centimeter markings, wherein the gummed paper is aligned and superimposed to form a 2 x 2cm square. Alternatively, the 2 x 2cm area may be isolated by using any means of delimiting the perimeter of the area, such as with a ruler and ink that can be washed off, a marker pen, a marker template and/or a simple comb-shaped device of length 2cm that simultaneously combs the hair into a bundle and delimits the perimeter of the area.

In one embodiment, the bundle of hair is placed in a slot (slit) of a two-part cartridge of the invention (one part being slidable in the other part, the slot being of variable length and 1mm wide) and then placed on the "L" or "J" end of a plunger (plunger) protruding from the first end of the body (body) of the measuring mechanism or device of the invention. The plunger is pulled into the body of the device of the present invention to compress the hair in the slit as the two parts of the cartridge are pushed together between the "L" or "J" shaped end and the first end of the body. The plunger has a spring disposed between the second end of the body of the device and the inner end of the knob at the outer end of the plunger. The spring forces the "L" or "J" shaped terminal toward the body to compress the hair strands, the amount of compressed hair can be read from a gauge on the device body, and the "L" terminal is covered by the cartridge to isolate it from the surrounding hair for hygiene. This measurement is called the DDI or density-diameter index and represents the total density and diameter of all hairs in the bundle.

The normal range of DDI is 3.00-4.00mm, which is fine hair when less than 3.0. After the test is completed, the smaller portion of the cartridge is partially withdrawn from the larger portion of the cartridge, allowing the cartridge to be easily removed from the bundle of hair and discarded.

In another embodiment, the bundle of hair is hooked with a hook-shaped ("J-shaped") arm with a light weight spring, which is then pulled into the body of the device of the present invention. The device comprises a hair-gripping element comprising a "J-shaped" terminal end, projecting through a boss (boss) and having slots (slots) for receiving hair. The device further includes an anvil (anvil) located at one end of the face of the boss, which is connected to the slot, and which compresses hair placed in the slot by relative movement between the "J" shaped end and the anvil. The device also includes a relatively heavy compression spring for supporting the boss. Alternatively, the device has an anvil that can be inserted into a stationary slot.

The bundle of hair is secured in the slot and automatically secured to an anvil on the boss. The slot has a width of 1mm, preferably a height of between 7-12mm, and the height of the hair is measured by relative movement between the anvil and the slot. By using a weighted compression spring, the load applied to the fixed hair column can be accurately maintained and thus maintained at a constant value during repeated tests. This is important because the hair strands are easily compressible. The mm height of the hair bundle is displayed in an LED window of an integrated micrometer tip that causes relative movement between the anvil and the slot. If a mechanical height gauge is incorporated into the device, it will appear on the dial-like surface. If an electrically powered height gauge is incorporated into the device, the height value is displayed in the LED window. The height of the hairs in the hair-holding receiving slots can be any value, referred to as a density-diameter index, a hair mass index, a cross-sectional area index, a total cross-sectional area index, or a combined cross-sectional area index, etc.

The test method can be used for thin hair areas, as well as for permanent hair growth edges on the back and sides of the scalp. Dividing the index value of the hair thinning zone by the index value of the permanent zone gives the percent hair mass loss in the hair thinning zone. It is believed that the methods and devices of the present invention may have profound medical significance for the following reasons: it is a well-known medical fact that a person with thin hair must lose half the hair mass before it is visibly apparent to a casual observer that the hair has been lost. This is also evidenced by the fact that a casual observer cannot distinguish between a hairpiece having 100 hairs per square centimeter and a hairpiece having 200 hairs per square centimeter. However, this finding can also be expressed in the following way: when a person realizes that he is "losing hair", he has already lost half of his hair. The device of the present invention enables hair professionals and physicians to measure hair quality in areas of the hair that appear normal before the patient is balded and compare that value to hair quality measurements in permanent areas. The device can therefore detect the earliest changes in hair diameter, an early sign of baldness. By this test we can find out if there is hair loss several years before the patient or his physician clearly sees it. Thus, the patient can be alert to early hair loss before the hair loss phenomenon is severely developed and enjoy the advantages of early treatment. The method and apparatus may also be used to track and quantify the progressive hair loss of untreated balding individuals or to track and quantify the treatment effects of drugs and devices used to grow hair.

Drawings

Fig. 1 is a top view of a scalp showing a portion or bundle of hair combed from a delineated section of scalp by a comb element, the diagram showing one side of the portion of scalp being delineated by an adhesive label.

Fig. 2 is a top view of a scalp showing a portion or bundle of hair combed from a delineated section of scalp and showing both sides of the portion of scalp being delineated by gummed labels.

Fig. 3 is a top view of a scalp showing a portion or bundle of hair combed from a delineated section of scalp and showing three sides of the portion of scalp being delineated by gummed labels.

Fig. 4 is a top view of a scalp showing a portion or bundle of hair combed from a delineated section of scalp and showing four sides of the portion of scalp being delineated by gummed labels.

Figure 5 is a plan view of one comb element.

Fig. 6 is a plan view of the scalp shown in fig. 4 and a device for measuring the cross-sectional area of a bundle of hair made in accordance with the teachings of the present invention.

Fig. 7 is a top plan view of the scalp shown in fig. 6 and the "J" shaped end of the device moved toward a boss on the body of the device to measure the cross-sectional area of a bundle of hair positioned in the slot of the "J" shaped end.

Fig. 8 is an enlarged view of a portion of hair held in a "J" shaped terminal slot.

Fig. 9 is a cross-sectional view of the "J" shaped terminal taken along line 9-9 of fig. 8.

Fig. 10 is a cross-sectional view of the boss extending from the body of the device and with the "J" shaped terminal end received therein.

Fig. 11 is a plan view of the device without a bundle of hair in the slot of the "J" shaped terminal, showing the "J" shaped terminal moved over the boss and the split showing the heavy pressure spring within the body of the device.

FIG. 12 is a perspective view of a marking template having a center locating pin and four ink markers, one at each corner of the template.

Fig. 13 is a marked scalp portion in an area of the scalp where hair testing is to be performed.

Fig. 14 is an exploded view of two parts of a cartridge with a variable length slit therebetween for gripping the isolated hair shown in fig. 13 for measuring the bundle of hair isolated in fig. 13.

Fig. 15 is an exploded view of the cartridge showing the two parts of the cartridge exploded ready to clamp a bundle of hair isolated from the scalp.

FIG. 16 is a perspective view of a measuring device, a plunger having an "L" shaped end, wherein it works in conjunction with a larger portion of the cartridge to push the two portions of the cartridge together between a first end of the device and an outer end of the "L" shaped plunger.

Fig. 17 is a perspective view of the two parts of the cartridge pushed together by the action of the "L" shaped plunger, which is pushed towards the first end of the device by the action of the spring on the other end of the plunger at the other end of the device, showing a measure of the compressed bundled hair in the variable length slit, and showing how the cartridge wraps the "L" shaped plunger so that it does not contact the surrounding hair.

Fig. 18 is a perspective view of the device with the plunger again moved outwardly and the cartridge moved away from the bundle of hair, allowing the bundle of hair to be easily pulled out of the slot between and in the cartridge by moving the smaller portion of the cartridge a short distance away from the larger portion.

Fig. 19 and 20 are side and top views, respectively, of a head showing numbered hair regions on the scalp.

Detailed description of the invention

Referring initially to fig. 1, there is illustrated a bundle or portion of hair 10 combed from the scalp 12 by a comb or combing element 14. The bundle of hair 10 is separated from a pre-designated area of the scalp 12 by the adhesive labels 16 without cutting the bundle of hair 10.

As shown in fig. 2 to 4, the defined scalp area is fixed using adhesive labels 18, 20, 22 in sequence. Each gummed label has a centimeter scale printed thereon so that a predefined area, such as 2 square centimeters, is measured and isolated from the rest of the scalp hair by gummed labels 16, 18, 20, 22. The adhesive labels 16, 18, 20 and 22 are printed with 2 cm-spaced graduation marks. The colour marking line is aligned with the edge of the previous label and overlapped in 4 steps in sequence to form an isolated area of uncut hair of 2cm square.

Preferably, the hair is combed from the scalp of the defined square by a comb, and the 2 x 2cm of hair is isolated manually. This step is done in the order described above. Care is taken to maintain a straight line and at a 90 degree angle to the previous hair line path of the comb element 14.

The comb element 14 is shown in fig. 5 and comprises a predefined tooth surface 26, for example 2cm long, with pointed teeth 28 and an upwardly inclined top edge 29, said top edge 29 extending to a handle 30.

The present invention provides a device 32, as shown in fig. 6, for measuring the mass of hair in a bundle of hair 10 having a scalp area of 2 square centimeters and comparing the mass of hair to the mass of hair per square centimeter of a permanent (normal) scalp area.

The device 32 is an electronic caliper 34 having a body 36 with an electronic display 38 and a scale, gauge or analog display 40 for indicating the height or quality of the hair of the bundle 10.

The device 32 includes a piston (piston) or plunger 42 extending from the body 36, and a collar (collar)43 is fitted over the plunger, the collar 43 being located downstream of a knob 44, wherein the knob 44 is located at an outer terminal end 46 of the plunger 42. A lightweight return spring 48 (see fig. 7) supports collar 43 and forces knob 44 away from upper end 49 of body 36, pushing plunger 42 upward. As shown, a collar 50 is provided between the spring 48 and the upper end 49 of the body 36 and has a small diameter portion 51 that extends into the body 36.

It will be appreciated that the scale, gauge or analog display 40 moves with the plunger 42. Of course, the distance the plunger moves is also displayed on the display 38.

The other end 52 of the plunger 42 has a "J" shape defined by a main leg 53 and a hook leg 54 with a slot 56 therebetween. The slot 56 is 1mm wide and 12mm high.

The main leg 53 passes through a through hole 58 (see fig. 9) in a boss 60 at a lower end 61 of the body 36.

As shown in fig. 11, the body 36 includes a heavy compression spring 62 therein which contacts a lower terminal end 63 of the smaller diameter portion 51 of the collar 50.

The wall 64 of the boss 60 between the through bore 58 and the outer surface 63 of the boss 60 is slidably received in the slot 56 during relative movement between the boss 60 and the "J" shaped terminal end 52.

The bundle of hair 10 is positioned in the slot 56 and the knob 44 is screwed down onto the plunger 42 to move the smaller diameter portion 51 of the collar 50 into the body 36 to compress the hair 10 between the bottom 66 of the slot 56 and the terminal surface 68 of the wall 64 with a predefined compression force (see fig. 9) controlled by the spring constant of the heavy spring 62 acting on the plunger 42. The terminal surface 68 may be referred to as an anvil 68 by which the hair bundle 10 is compressed. Thus, the device 32 is a measuring device that includes the hair-receiving slot 56, the "J" shaped end of the spring-loaded plunger 42, and the anvil 68.

The bundle of hair 10 is placed in the slot 56 and compressed by the anvil 68 to measure the height of the column or bundle of hair 10. The anvil 68 and plunger are designed to always apply the same pressure to the hair 10 held by the post or bundle. (this can be achieved by a heavy compression spring 62 attached to the smaller diameter portion 51 of the collar). This is important because the tress of hair 10 is very easily compressed. The millimeter height of the bundle or column of hair 10 may be read from a window in the electronic display 38 and/or from a ruler, gauge or analog display 40. This arbitrary value is called the alopecia index or density-diameter index. The test procedure was performed in the balding area and in the permanent hair growth area. The percentage of hair mass loss in the balding area is determined by dividing the value in the balding area by the value in the permanent area. When used to determine the therapeutic effect of a hair growth product, measurements should be made and compared on the same area before and after treatment, respectively.

Surprisingly, in alopecia areata (androgenic alopecia), there is no reduction in hair on the back and both sides of the scalp, a phenomenon called miniaturization by physicians. Thus, on a bald scalp, the permanent horseshoe-shaped rim typically has normal size hair (70 microns) and normal density hair in the range of 150 to 250 hairs per square centimeter. On the top of the scalp, in the area of hair loss, the hair sizes range from 70 microns to 15 microns in diameter, with a wide variation in hair diameter per square centimeter.

The total number of hairs per square centimeter of scalp multiplied by their total diameter is better described as the mass of the hair. When the hair mass value of the balding area is divided by the hair mass value of the normal permanent area (area 10), the percent loss of hair mass in the balding area is obtained. When the hair mass value of an area of hair loss is compared to the hair mass value measured for the same area at a future time, the percentage of hair loss or growth can be obtained.

This information is important to those concerned with patients suffering from hair loss, and those developing drugs and devices to promote hair growth. It is important to re-emphasize that although the length of the hair contributes to the visual quality of the whole hair, it is not considered, since the length of the hair varies with the cut of the hairstyle and is not relevant to the final application of the patent.

It will be appreciated that modifications to the method and apparatus of the invention described above may be made without departing from the teachings of the invention.

For example, a mark may be placed on the body 36, another mark may be placed on the plunger 42, and a separate caliper may be used to measure the distance between the marks to determine the height of the compressed hair in the slot 56.

The heavy spring 62 may be omitted and the knob 44 tightened with a torque wrench to apply a predetermined pressure to the bundle of hair 10.

A simple projection with an anvil at one end may be used in place of the boss 60 and received in the slot 56.

A simpler device can be provided that includes a body with a slot 56 and a piston having an anvil 68 at one end is provided and placed in the slot 56. The body may move relative to the piston, or the piston may move into or out of the slot 56.

The body and piston may have a return spring, like spring 48, for holding the anvil 68 in the slot 56 until the spring is compressed to move the anvil 68 out of the slot 56.

If desired, side arms may be provided on the body, much like a syringe, to facilitate easy gripping of the body as the piston or plunger is reciprocated or the knob 44 is rotated.

The hair that is not isolated may be pressed by other means, such as a ruler or a hair clip, instead of a label with adhesive.

Still further, the caliper may be mechanical or electrical/electronic, and may be coupled to the body or plunger, or separate from the device 32.

Fig. 12 illustrates a marking template 80 for marking the area of the scalp where the bunched hair is located. The marking device 80 includes a rectangular platform 82, preferably 2cm square, having four depending ink pens 84 at its four corners. At the center of the platform 82 is a reciprocatable pin 86, the pin 86 having a lower stylus 88 and an upper knob 90.

During use of the marking device 80, measurements are first taken with a flexible measuring tape (not shown) from a location on the face to an area on the scalp where the markings are made. See fig. 19 and 20. A typical starting point for the tape measure is the intersection of the nose and upper lip, i.e. the base of the bridge of the nose. The exact dimensions of the scalp mark location are recorded so that later repeated measurements are made at the same location mark. Permanent and semi-permanent skin tattoos are one form of marking that can be selected.

The marked location in the scalp region is then used by the marking template 80. First, four nibs 84 are dipped in ink. The stylus 88 of the center pin 86 is then placed in the position just marked on the scalp. Next, the marking template 80 is lowered so that the four ink pens 84 make four ink marks 91-94 on the scalp, as shown in FIG. 13. The bundles 95 of hair 96, separated and integrated into one bundle from the square area defined by the four markers 91 to 94.

As shown in fig. 14, a two-part chuck 100 includes a larger rectangular portion 102 and a smaller rectangular portion 104, wherein the smaller portion 104 is designed to slidably move into a rectangular cross-section slot 106 in the larger portion 102. The smaller rectangular portion 104 has a transverse slot 108 that mates with a transverse slot 110 in the larger rectangular portion 102. The transverse slot 110 also passes through the slot 106 of the larger rectangular portion 102.

Preferably, as shown in fig. 14, the larger rectangular portion 102 has a side slot 112 extending within and around three sides of the larger rectangular portion 102 for receiving an "L" or "J" shaped terminal end of a plunger, the connection of which is described in more detail in conjunction with the description of fig. 15-18. The rectangular portions 102 and 104 may be made of any material, preferably plastic.

On the side at the entrance of the transverse slot 110, the larger portion 102 has two hair spreading walls 114 and 116 to facilitate entry of the bundle 95 of hair 96 into the slot 110. When the smaller section 104 is moved into the slot 106 of the larger section 102, the slits 108 and 110 and the chuck members 102 and 104 fit together and hold the bundle 95 of hair 96 in the mating slits 108 and 110.

Although the dimensions of the slots 108 and 110 can vary, the width of each slot 108 and 110 is preferably 1mm, and the length of each slot 108 and 110 is about 7-12 mm. The 1mm width of the slits gives the height of the compressed hair in the slits a simple value which can be read by the gauge, and this value is not only the height of the bundle of hair but also the cross-sectional area of the bundle of hair in square millimeters.

In a preferred embodiment, as shown in fig. 14, the smaller portion has a recessed wing, tab, barb or detent structure 118 on at least one side wall 120 (or on opposite side walls) that can snap into an aperture 122 in a wall 124 between the socket 106 and the side socket 112 (or two detents can be provided, one in each of the opposite apertures in the walls of the socket 106). Of course, other auxiliary mechanisms may be utilized, such as a resilient eccentric ball, or a detent or mating hole, etc. The detent 118 may allow the smaller portion 104 to be pushed into the slot 106 but only partially out of the slot 106, that is, until the detent 118 snaps into the hole 122.

Whether a smaller or larger portion of the chuck, can be designed to have a member that extends about 10mm outward from the open end of the slot and parallel to the walls of the slot. This configuration facilitates the collection and introduction of hair into the open end of the slot and down into the slot.

As shown in fig. 15, the two portions 102 and 104 cooperate to space the bundle 95 of hair 96 from the indicated scalp surface, with the smaller portion 104 sliding into the slot 106, so that the bundle 95 of hair 96 is clamped in the mating slits 108 and 110.

Then, as shown in FIG. 16, the measuring mechanism or device 130, similar to device 32, is manipulated to engage the "L" shaped terminal end 132 of the plunger 134 extending through the body 136 of the device 130 with the larger portion 102 of the cartridge 100, i.e., into the side slot 112 of the larger portion 102. The slot 112 bounded by three sides of the larger portion 102 ensures that cross-contamination does not occur between the oil or other material on the strands 95 of hair 96 from one measurement to another. As the cartridge 100 can be discarded and the cartridge 100 can be completely detached from the device 130, particularly the "L" shaped terminal 132.

The outer terminal end 138 (see fig. 14) of the smaller portion 104 is adjacent a first or inner terminal end 140 of the body 136 of the device 130 for forcing the outer terminal end 138 through the "L" shaped terminal end 132 to press the bundle 95 of hair 96 into the slots 108 and 110 upon release of the knob (146).

The plunger 134 extends from a second or outer terminal end 142 of the body 136 with a collar 144 to a knob 146. A spring 148 is located on an outer portion 150 of the plunger 134 and extends to the knob 146 and is interposed between an internal shoulder (not shown) within the collar 144 and the knob 146. It will be appreciated that the knob 146 is pushed toward the body 136, compressing the spring 148 to extend the "L" shaped end 132. Then, after the cartridge 100 with the bundle 95 of hair 96 sandwiched therebetween is secured to the "L" shaped end 132, the knob 146 is released to push the two cartridge portions 102 and 104 toward each other to press the bundle 95 of hair 96 into the mating, variable length slits 108 and 110, as shown in FIG. 17. The length of the mating slits 108 and 110 typically ranges from 1 to 4mm and the width is constant at 1mm when a bundle of hair is pressed therein. An electronic meter 152 mounted on the body 136 of the device 130 displays the measurements. Spring 148 and possibly another spring within body 136 provide constant pressure for all pressure tests of hair strands clamped in mating, variable length slots 108 and 110. Experiments have shown that the measurement is very accurate and that a difference of 4 hairs in a bundle results in a measurement of 3.34 and 3.35, respectively. This measurement is referred to as the DDI or Density-diameter index and represents the total density and diameter of all hairs in bundle 95, which DDI has a value of 2.98 in the illustrated test.

The device 130 preferably has two side arms or handles 153 and 154, the handles 153 and 154 being adjacent the outer end 142 of the body 136, much like a syringe, so that the device 130 is gripped like a syringe for moving the "L" shaped end 132 of the plunger 134 inwardly and outwardly.

After the measurement is completed, the inner smaller portion 104 of the cartridge 100 is withdrawn slightly from the larger portion 102 until the detent 118 locks the opening 122, slowly increasing the length of the mating slits 108 and 110, which allows the cartridge to be easily removed from the bundle of hair, as shown in FIG. 18. The cartridge 100 is then disposed of so that each cartridge 100 is used only once. This ensures that there is no cross-contamination between the oil or other material on the hair from one measurement to another.

The cartridge 100 and device 130 provide a simple and effective mechanism for measuring bundled hair, making the method of measuring the DDI of bundled hair more convenient to use, and allowing the measurement of a bundle of hair in the same designated scalp area to be accurately reproduced. Of course, hair in other areas 1-10, (see fig. 19 and 20) can be measured as well.

The device 32, the device 130 and the cartridge 100 have many advantages, some of which are described in the foregoing description, and others of which are also present in the device 32 or the device 130, the cartridge 100 itself and the method for measuring DDI using the same.

Accordingly, the scope of the invention is defined by the appended claims.

Claims (3)

1. A device for measuring the cross-sectional area of uncut hair in a pre-measured area of the scalp with hair, said device comprising a slit for receiving a bundle of uncut hair, an anvil adjacent to said slit for relative movement with respect to said slit, a compression spring associated with either said slit or said anvil to compress the uncut bundle of hair with a pre-defined, precise amount of pressure, said compression spring being mechanically constrained in a position to accurately apply the pre-defined, precise amount of pressure to a variable number of uncut hair bundles in said slit.

2. The device of claim 1, comprising a separate or integrated device for measuring or indicating the amount of movement between the bottom of the slot and the anvil when a bundle of uncut hair is pinched into the slot and squeezed in the slot.

3. The device of claim 1, wherein the slot has a width of 1 mm.