Simple blood sampling device

Abstract: A simple blood sampling device composed of a vacuum chamber (11), a skin suction portion (17) and a piercing and cutting (12) means.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple blood sampling device. 2. Description of the Related Art In recent years, the numbers of persons suffering from various diseases derived from rich dietary patterns and increased stress, for example, diabetes, have been soaring. Trips to the hospital pose a major inconvenience to patients in their daily activity, so as examinations of blood sugar etc. over the course of the regular day become part of the daily routine, the method of sampling blood has come under attention as a large problem. The problem of the pain involved in the blood sampling becomes an even greater problem when it has to be repeated. In particular, this is becoming a further serious problem in the case of insulin-dependent patients, many of whom are small children. Further, in recent years, diseases transmitted through the blood have become social issues. To prevent AIDS, hepatitus, and other especially serious diseases, some sort of device which enables patients themselves to sample their own blood without problem is needed. DE-A-3708031 discloses a blood sampling device according to the preamble of claim 1, the device comprising a vacuum chamber and a skin suction portion having a piercing or cutting means therein. The device can be retained in the vacuum state in the skin suction portion during the collection of blood. However, the portion of the device contacting with the skin cannot be adapted to curved contours of the human body. Moreover, the device is relatively voluminous. SUMMARY OF THE INVENTION Accordingly, the objects of the present invention are to eliminate the above-mentioned disadvantages in the prior art and to provide a device capable of sampling blood in a painless state. Other objects and advantages of the present invention will be apparent from the following description. In accordance with the present invention, there is provided a simple blood sampling device comprising a vacuum chamber, a skin suction portion for providing a reduced pressure state to the skin of patient in cooperation with the vaccum chamber, and a piercing or cutting means provided in a central cavity, characterized in that the vacuum chamber is formed in a reduced pressure state in advance by an air-tight material and is joined to a support member on the top of the same at the periphery of the central cavity, in that said support member has flexibility capable of uniformly contacting with the skin and delimits the central cavity therein, in that said skin suction portion is formed by the inside surface of the central cavity of the support member and by the bottom portion of the vacuum chamber, and in that said device further comprises an adhesive for affixing the device to the skin, provided at the bottom of the support member at the outer periphery of the same, and a stopper made of a material which is suitable for causing a large friction with the skin and provided in the form of a ring having a uniform height at the bottom of the support member at the periphery of the central cavity to cause large friction with the skin at the time of application of vacuum. In the device as defined in claim 1 the cutting means may be provided at the inner periphery of the skin suction portion to thereby painlessly cut the skin epidermis sliding thereagainst. The present device is extremely simple in construction and further is small in size and light in weight and also does not use any special parts, so that the present device is low in price and can be used as a disposable device. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood from the description set forth below with reference to the accompanying drawings; wherein: Fig. 1 is a view showing an example of the present device, Figs. 2 and 3 are views for explaining the operation of the example shown in Fig. 1; Fig. 4 is a sectional view showing another example of the present device; Fig. 5 is a bottom view of the example shown in Fig. 4; Fig. 6 is a sectional view showing another example of the present device; Fig. 7 is a view for explaining the operation of the example shown in Fig. 6; and Fig. 8 is a view for explaining the case of use of the example shown in Fig. 6. DESCRIPTION OF THE PREFERRED EMBODIMENTS The characteristics of the present device will now be explained. A vacuum suction action is applied to a local portion of the surface of the skin of the subject (i.e., the living body). Along with this local vacuum suction, the area inside the subject's skin becomes engorged with blood and therefore the epidermis expands and rises up. This raised portion of the skin comes in contact with a piercing means provided at a predetermined position. Since the raised portion of the skin is sufficiently taut in state, the piercing means pierces the skin (epidermis) easily. When the piercing means pierces the skin, the blood engorged inside it flows out and is collected. Since the skin is locally drawn up, even though the piercing means pierces the skin, it does so instantaneously and the sensation of this is cancelled out by the stimulus caused by the suction action, so no pain is felt. Further, the piercing and cutting means pierce and cut in an engorged state, so the blood can be collected painlessly and reliably. The vacuum chamber shown in the present device is a means for drawing up the surface of the subject's skin. Ones which perform the vacuum action mechanically and chemically may be mentioned. While not particularly limited to them, ampules, cassette devices, etc., which are formed in a vacuum state in advance by an air-tight material may also be mentioned. Further, the piercing and cutting means may be one or more solid needles, hollow needles, needles with sawtooth sides, acupuncture type needles, etc. The length of the piercing and cutting means is preferably about several 100 micrometers to several millimeters, but is not particularly limited. Further, regarding the disposition and construction of the same, the means may be disposed at the center of the suction portion or the periphery of the same. It is sufficient if the means can make use of the stretching action of the epidermis by the vacuum suction to painlessly and effectively pierce or cut through the epidermis. EXAMPLES The present invention will now be further illustrated by, but is by no means limited to, the following Examples. Figure 1 is a view showing one example of the present device. Reference numeral (11) is a vacuum chamber, which houses a vacuum drive portion. At the top of the vacuum chamber (11) is provided a switch (16). By pressing this switch (16), the vacuum operation is performed. Reference numeral (100) is a hole portion, one or more of which are provided through the bottom of the vacuum chamber. Reference numeral (12) is a piercing means, which is formed by, for example, a fine needle and is provided at the bottom of the vacuum chamber (11) near the hole portions (100). Reference numeral (13) is a support member, which is formed as a concentric cylindrical film by plastic, rubber, paper, or another material having flexibility. The vacuum chamber (11) is joined to the support member (13) on the top of the same at the periphery near the approximate center of the concentric portion. Reference numeral (14) is an adhesive. Use is made of a material which does not react with the body, such as a material used for adhesive plaster. The adhesive (14) is provided at the bottom of the support member (13) at the outer periphery of the same. Examples of such an adhesive are rubber-based adhesives, acryl-based adhesives, silicone-based adhesives. Reference numeral (15) is a stopper, which keeps down the elongation and contraction of the support member (13) at the time of application of vacuum and assists the skin in being pulled up. The stopper (15) is provided at the bottom of the periphery of the approximate center of the concentric portion of the bottom of the support member (13). The material for the stopper is rubber, plastic, etc. so as to cause large friction with the skin. Reference numeral (17) is a suction portion, which portion is formed to cover the inside surface of the concentric portion of the support member (13) and the bottom portion of the vacuum chamber, including the piercing means (12) and the hole portions (100). Next, the operation of the example shown in Fig. 1 mentioned above will be explained in detail with reference to Fig. 2 and Fig. 3. First, the above-mentioned example of the present invention is placed, with the adhesive portion (14) down, on a position of the subject's skin (MMA) suitable for sampling blood. The adhesive portion (14) adheres to the subject's skin (MMA), so the device is affixed to the surface of the subject's skin and the suction portion (17) is sealed. At this time, the piercing means does not contact the subject's skin. The switch (16) is depressed. The vacuum chamber thereby begins the vacuum operation. By this vacuum operation, the suction portion (17) enters a vacuum state through the holes (100) and a suction action is applied to the subject's skin under the suction portion (17). By this suction action, the body fluid, including the blood, inside the subject's skin (MMA) begins to engorge, forming the engorged position (MMB). Gradually, as shown in Fig. 3, the subject's skin under the suction portion (17) begins to rise up and contacts the piercing means (12). The subject's skin at this portion, in the pulled up state, is locally taut, so the piercing means (12) easily pierces the epidermis at the subject's skin (MMA) and the vacuum reaches the engorged portion (MMB). At this time, the stopper (15) prevents the movement of the skin under the stopper (15) by a suction action and assists the surface of the subject's skin being raised up. The blood and other body fluid travel along the piercing means (12) and are sucked out to the surface of the subject's skin where they are collected. In accordance with need, further, the blood sucked out to the surface of the subject's skin is taken into the inside of the vacuum chamber (11) through the holes (100). Finally, the device of this example is taken off the subject's skin surface (MMA). Further, Fig. 4 shows a cutting means (121) disposed at the periphery of the suction portion. When the epidermis is pulled up and stretched by the vacuum, the surface of the epidermis contacts and slides against the fine sawtooth edge (122) of the cutting means and is painlessly cut. The cutting means is formed to have a sawtooth edge construction over all or part of its edge. Figure 5 is a view looking at Fig. 4 from the bottom. Reference numeral (100) is a hole portion, which communicates the vacuum chamber (11) with the suction portion (17). The rest of the construction is the same as in Fig. 1, so the same reference numerals are attached and the explanations are omitted. Next, a further example will be shown in Fig. 6 and explained. The device according to this example shown in Fig. 6 is provided with a vacuum drive portion inside and further has a plurality of piercing means. Reference numeral (51) is a holding piece which is provided so that a sliding member A (52) and a sliding member (B) are held at predetermined positions so as not to separate. The sliding member A (52) and the sliding member B (53) slide left and right and are connected by a spring (54). The portion over which the sliding member A (52) and the sliding member B (53) face each other constitutes a vacuum space (55). Reference numeral (12) is a needle, a plurality of which are provided at the bottom of the vacuum chamber (11). Reference numeral (100) is a hole portion, of which a plurality are made and which connect the vacuum space (55) and the suction portion (17). Reference numeral (56) is a peeling member, which prevents the drying and reduction of tackiness of the adhesive (14) and which is peeled off at the time of use. The rest of the construction is the same as in the example shown in Fig. 1 and thus will not be explained. Next, an explanation will be made of the operation of the example shown in Fig. 6, including Fig. 7. At the time of use, the peeling member (56) is peeled off and the device is placed on the position of the body for drawing the blood. The sliding member A (52) and the sliding member B (53) are affixed at predetermined positions by a holding piece (51). At this time, a spring (54) maintains the compressed state. Next, the holding piece (51) is removed, as shown in Fig. 7. The sliding member A (52) and the sliding member B (53) are pushed outward by the force of the release of the spring (54) and the vacuum space (55) grows in volume. At the time of adhesion, the suction portion (17) and the vacuum space (55) were sealed by the subject's Skin, so when the vacuum space (55) grows, the skin under. the suction portion (17) is pulled up. Blood engorges under the skin and the surface rises up. The piercing means (12) contacts the skin, then pierces through it. When the piercing means (12) reaches the engorged portion, the blood comes out along the surface of the piercing means (12) and is thus extracted. The time waiting for blood to engorge after the skin is drawn up and the time until the piercing means pierces, the skin also may be suitably selected. Further, it is not that particularly necessary to wait for the blood to engorge. So long as the skin is pierced by the piercing means in a state after suction when there is tautness in the skin due to its being drawn up, the present device operates sufficiently. Next, the state of one of the examples shown in Fig. 6 adhered to the upper arm of the body is shown in Fig. 8. Reference numeral (11) shows a vacuum chamber, and (13) a support member. Since the device is small in size and light in weight, it may be used adhered in the manner shown in Fig. 8 as well. Also, the adhesive portion is suitably used. As explained above in detail, the present device is small in size, light in weight, and low in price and therefore has the effects that it is suited as a disposable implement and further enables blood to be drawn reliably etc.

Claims: A simple device for sampling blood from a skin comprising: a vacuum chamber (11), a skin suction portion (17) for providing a reduced pressure state to the skin of patient in cooperation with the vaccum chamber, and a piercing or cutting means (12) provided in a central cavity, characterized in that the vacuum chamber (11) is formed in a reduced pressure state in advance by an air-tight material and is joined to a support member (13) on the top of the same at the periphery of the central cavity, in that said support member (13) has flexibility capable of uniformly contacting with the skin and delimits the central cavity therein, in that said skin suction portion (17) is formed by the inside surface of the central cavity of the support member and by the bottom portion of the vacuum chamber, and in that said device further comprises an adhesive (14) for affixing the device to the skin, provided at the bottom of the support member at the outer periphery of the same, and a stopper (15) made of a material which is suitable for causing a large friction with the skin and provided in the form of a ring having a uniform height at the bottom of the support member at the periphery of the central cavity to cause large friction with the skin at the time of application of vacuum. A device as claimed in claim 1, wherein the cutting means (12) is provided at the inner periphery of the skin suction portion (17) to thereby painlessly cut the skin epidermis sliding thereagainst.

Inventors: ISHIBASHI HIROMU, ISHIBASHI, HIROMU
Applicants: ADVANCE KK, KABUSHIKI KAISYA ADVANCE
Application year: 1992
Main classification: A61B5
IPC codes: A61B5