# US 4,396,024 A · Device for the extraction of capillary blood

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- Number: US 4,396,024 A
- Document ID: US4396024A
- Status: Granted
- Kind: A
- Application number: 06/090,750
- Filed: 1979-11-02
- Granted: 1983-08-02
- Earliest claimed: 1978-11-09
- Inventors: Walter Sarstedt
- Web page: https://patentgrep.com/patent/US4396024A

## CPC

- A61B 5/02125: {of pulse wave propagation time}
- A61B 5/150022: {for capillary blood or interstitial fluid}
- A61B 5/150213: {Venting means}
- A61B 5/150305: {Packages specially adapted for piercing devices or blood sampling devices}
- A61B 5/150343: {Collection vessels for collecting blood samples from the skin surface, e.g. test tubes, cuvettes (sampling from within body cavities A61B5/150015, A61B5/150045)}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

In a device for the extraction of capillary blood including a capillary open at both ends and being of a predetermined volume, having a capillary effect at least at the front end thereof, a holder is integrally connected to said capillary which is provided with one or more windows. For avoiding dosage errors, a closure pin for the rear end of the capillary or in a modification a rear transverse wall having one or more air exit apertures is provided.

## Claims

### Claim 1

A device for the extraction of capillary blood comprising:
a capillary portion having front and rear ends;
a capillary passage extending between said front and rear ends;
a first opening a said front ends for the introduction of blood into said capillary passage by capillary action;
a second opening at said rear end for venting said capillary passage;
a holder at said rear end for supporting said capillary portion and having an outer surface;
a closure pin axially movable within said holder between a first position in which said pin restricts the size of said second opening and a second position in which said pin does not restrict the size of said second opening; and
window means in said holder communicating between said second opening and said outer surface.

### Claim 2 (depends on 1)

A device as set forth in claim 1, wherein said capillary passage flares from said front end to said rear end.

### Claim 3

A device for the extraction of capillary blood comprising:
a capillary portion having front and rear ends;
a capillary passage extending between said front and rear ends;
an opening at said front end for the introduction of blood by capillary action into said capillary passage;
a holder at said rear end for supporting said capillary portion and having an outer surface;
a closure pin having an end face;
an opening into said capillary passage at said rear end wherein said closure pin face and said rear end opening cooperate to define an air exit aperture smaller in area than said capillary passage;
window means in said holder communicating between said air exit aperture and said outer surface; and
a guide and retaining rod integrally connected with said closure pin, said guide and retaining rod being displacable in an axial direction relative to said holder.

### Claim 4 (depends on 3)

A device as set forth in claim 3, further comprising:
means for clampingly locating said rod in said holder with said closure pin end face contacting said capillary portion rear end at said rear end opening.

### Claim 5 (depends on 4)

A device as set forth in claim 4, wherein said retaining rod for said closure pin is formed as an extended handle.

### Claim 6 (depends on 4)

A device as set forth in claim 4, wherein said means for clampingly locating said rod in said holder comprises at least three guide vanes projecting radially from the axis of said rod.

### Claim 7 (depends on 3)

A device as set forth in claim 3, wherein closure pin has a centering projection at said end face.

### Claim 8 (depends on 7)

A device as set forth in claim 7, wherein said centering projection is part-spherical.

### Claim 9 (depends on 8)

A device as set forth in claim 8, wherein said part spherical centering projection has a periphery including recesses formed therein, said recesses cooperating with said rear end opening to define said air exit apertures.

### Claim 10 (depends on 7)

A device as set forth in claim 7, wherein said centering projection is of pyramidal form defining a number of roof edges.

### Claim 11 (depends on 10)

A device as set forth in claim 10, wherein said roof edges include abutment noses having abutment surfaces, said abutment surfaces radially projecting from said closure pin.

### Claim 12 (depends on 3)

A device as set forth in claim 3, wherein said closure pin has a depression in said end face.