US20140091104A1

US20140091104A1 - Syringe press

Info

Publication number: US20140091104A1
Application number: US14/039,182
Authority: US
Inventors: Robert L. Evans, III; Peder Cedervall
Original assignee: University of Minnesota
Current assignee: University of Minnesota
Priority date: 2012-09-28
Filing date: 2013-09-27
Publication date: 2014-04-03

Abstract

A syringe press includes a housing, a compressible member, and a compression mechanism. The housing includes a longitudinal axis, a first end and a second end. The housing is configured to support a syringe, which includes a cylinder configured to contain a fluid, and a piston having a seal configured to move within the cylinder, between the first and second ends. The compressible member is supported by the housing between the first end and the piston. The compression mechanism is supported by the housing and is configured to apply a compressive force to the piston, the cylinder and the compressible member, between the first and second ends and along the longitudinal axis. The piston is driven into the cylinder, and fluid is driven through an output of the cylinder responsive to the compressive force.

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based on and claims the benefit of U.S. provisional patent application Ser. No. 61/707,388, filed Sep. 28, 2012, the content of which is hereby incorporated by reference in its entirety.

FIELD

The present invention relates to a syringe press configured to drive fluid from a syringe.

BACKGROUND

Fluids used in scientific research, such as sensitive chemical or biochemical studies, must often be filtered. The filtering process removes dust, bacteria and other contaminates that may adversely affect the study.
In one technique for filtering a fluid, a syringe containing the fluid is attached to a filter. As the piston of the syringe is driven into the cylinder, fluid is driven through an output of the syringe and through the filter. The filtered fluid is then collected for use or delivered to the analytical equipment.
One system for driving of the fluid from the syringe involves the use of an electrical motor, such as a stepper motor. The motor drives the piston into the cylinder of the syringe to drive the fluid through the filter in a controlled manner. Unfortunately, such systems are complex and expensive.
A simpler option is to drive the piston of the syringe by hand. However, when the fluid is viscous, it can be physically challenging to drive the fluid through the filter. Additionally, this manual filtering of a fluid can be very time-consuming.

SUMMARY

Embodiments of the invention are directed to a syringe press for driving a fluid from a syringe, and a method of driving fluid from a syringe using embodiments of the syringe press described herein. In some embodiments, the syringe press includes a housing, a compressible member and a compression mechanism. The housing includes a longitudinal axis, a first end and a second end. The housing is configured to support a syringe, which includes a cylinder configured to contain a fluid, and a piston having a seal configured to move within the cylinder, between the first and second ends. The compressible member is supported by the housing between the first end and the piston. The compression mechanism is supported by the housing and is configured to apply a compressive force to the piston, the cylinder, and the compressible member, between the first and second ends and along the longitudinal axis. The piston is driven into the cylinder and fluid is driven through an output of the cylinder responsive to the compressive force.
In some embodiments of the method, a syringe, which comprises a cylinder for containing a fluid and a piston having a seal configured to move within the cylinder, is placed between first and second ends of the housing. A compressive force is applied to the piston, the cylinder, and a compressible member supported by the housing between the first end and the piston, between the first and second ends and along a longitudinal axis of the housing using a compression mechanism. The piston is driven into the cylinder and fluid is driven through an output of the cylinder responsive to applying the compressive force.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the Background.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified diagram of a syringe press in accordance with embodiments of the invention supported by a ring stand.

FIG. 2 is a simplified exploded diagram of an exemplary syringe press formed in accordance with embodiments of the invention.

FIG. 3 is a flowchart illustrating a method for delivering fluid from a syringe in accordance with embodiments of the invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Embodiments of the invention are described more fully hereinafter with reference to the accompanying drawings. Elements that are identified using the same or similar reference characters refer to the same or similar elements. The various embodiments of the invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it is understood by those of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, frames, supports, connectors, motors, processors, and other components may not be shown, or shown in block diagram form in order to not obscure the embodiments in unnecessary detail.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, if an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element could be termed a second element without departing from the teachings of the present invention.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Embodiments of the invention may also be described using flowchart illustrations and block diagrams. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in a figure or described herein.
FIG. 1 is a simplified diagram of a syringe press 100 in accordance with embodiments of the invention. The syringe press 100 is configured to deliver a fluid 102 from a conventional syringe 104. In some embodiments, the syringe 104 includes a cylinder 106 that is configured to contain the fluid 102, and a piston 108 having a seal 110 that is configured to move within the cylinder 106 in accordance with conventional syringes. The syringe press 100 operates to move the piston 108 relative to the cylinder 106 in the direction indicated by arrow 112 to drive the fluid 102 through an output 114 of the syringe 104.
In some embodiments, the syringe press 100 drives the fluid 102 through the output 114 of the syringe 104, and also through a filter 116, as indicated in FIG. 1. The filtered fluid 118 may then be collected in a container 120, as shown in FIG. 1, or discharged to an analytical device or other location.
Some embodiments of the syringe press 100 include a housing 122 having a longitudinal axis 124, an end 126 and an end 128. In some embodiments, the housing 122 is cylindrical. The housing 122 supports the syringe 104 between the ends 126 and 128, as shown in FIG. 1. In some embodiments, the output 114 of the syringe 104 extends through an opening 129 in the end 128.
In some embodiments, the housing 122 includes a removable cap 130 that includes the end 128. In some embodiments, the opening 129 is formed in the cap 130. In some embodiments, the housing 122 includes a removable cap 132 that includes the end 126.
In some embodiments, the housing 122 and other components of the syringe press 100 may be configured to accommodate different types of syringes 104. For instance, the housing 122 may use one cap 130 and/or other components of the housing 122 to accommodate syringes 104 having “Luer” fittings, while another cap 130 and/or other components of the housing 122 may be used to accommodate a syringe 104 having a different type of fitting.
The caps 130 and 132 may attach to a body 134 of the housing 122 using conventional techniques. In some embodiments, the syringe 104 is installed within the syringe press 100 by removing the cap 130 or cap 132 and inserting the syringe 104 into the housing body 134 in the orientation illustrated in FIG. 1. The removed cap is then re-attached to the housing 122 to complete the installation of the syringe 104. Alternative, techniques for loading the syringe 104 into the housing 122 may also be used, such as installing the syringe 104 through an opening in the side of the body 134, and other techniques.
In some embodiments, the syringe press 100 includes a compressible or elastic member 140 supported by the housing 122 between the end 126 and the piston 108, as shown in FIG. 1. In some embodiments, the compressible member 140 comprises a spring, such as a high-tension spring that is compressible along the longitudinal axis 124 of the housing 122. The length and materials used to form the spring may be selected to provide the compressible member 140 with the desired characteristics.
In some embodiments, the syringe press 100 includes a compression mechanism 142 supported by the housing 122. In some embodiments, the compression mechanism 142 is supported between the end 126 of the housing 122 and the compressible member 140, as shown in FIG. 1. In some embodiments, components of the compression mechanism 142 may extend outside the housing 122.
In some embodiments, an operator of the syringe press 100 manually controls the compression mechanism 142 by hand to apply a compressive force to the piston 108, the cylinder 106, and the compressible member 140. In some embodiments, the compressive force is applied along the longitudinal axis 124 and is counterbalanced by the ends 126 and 128 of the housing 122. As a result, the housing 122 is placed in tension in response to the compressive force generated by the compression mechanism 142.
The compressive force generated by the compression mechanism 142 operates to squeeze or compresses the compressible member 140, the piston 108, and the cylinder 106 between the ends 126 and 128 of the housing 122. This drives the piston 108 into the cylinder 106 and drives the fluid 102 through the output 114 and, optionally, through the filter 116.
In some embodiments, the compressive force is applied to the piston 108 and the cylinder 106 of the syringe 104 through a surface 144 that abuts an end of the piston 108, such as a flange 146, and a surface 148 that abuts an end 150 of the cylinder 106 adjacent the output 114, as shown in FIG. 1. In some embodiments, the surface 144 is a surface of the compressible member 140, or a component positioned between the compressible member 140 and the piston 108. In some embodiments, the surface 148 is a surface of the end 128, such as an inside surface of the cap 130, as shown in FIG. 1.
In some embodiments, the compressible member 140 is compressed along the longitudinal axis 124 of the housing 122 in response to the compressive force generated by the compression mechanism 142. As a result, the compressive force is stored within the compressible member 140 and applied to drive the piston 108 into the cylinder 106 causing the fluid 102 to be discharged through the output 114 over a period of time (discharge period). During this discharge of the fluid 102 through the output 114, the compressible member 140 expands along the longitudinal axis 124 until the syringe press 100 reaches an equilibrium state where the compressive force exerted between the compressible member 140 and the end 128 of the housing 122 is counterbalanced by the pressure required to drive the piston 108 in the direction 112 relative to the cylinder 106. Thus, the compression force applied by the compressible member 140 during the discharge period will decrease as the compressible member 140 expands along the longitudinal axis 124, and the rate of discharge of the fluid 102 through the output 114 will decrease over the discharge period.
As a result, after an operator manually operates the compression mechanism 142 to generate the initial compressive force that initiates a discharge of the fluid 102 from the syringe 104, the compression of the compressible member 140 will continue to drive the discharge of the fluid 102 from the syringe 104 over a period of time. In some embodiments, the period of time during which the compression of the compressible member 140 operates to drive the fluid 102 through the output 114 may be 10 minutes, 15 minutes or more. As mentioned above, when the compressible member 140 includes a spring, the length and other characteristics of the spring can be selected to provide the desired discharge period, during which the expansion of the compressible member 140 discharges the fluid 102 from the syringe 104.
FIG. 2 is a simplified exploded diagram of an exemplary syringe press 100 formed in accordance with embodiments of the invention. Elements having the same or similar reference number as those illustrated in FIG. 1 correspond to the same or similar elements.
In some embodiments, the housing body 134 is formed of PVC piping, such as piping having a diameter of 1.25 inches, for example. The length of the piping forming the housing body 134 may be selected as desired. In some embodiments, the caps 130 and 132 comprise PVC slip caps that cover the ends of the housing body 134. Other materials may also be used to form the housing 122, including plastics, aluminum or other suitable materials. Additionally, in some embodiments, the housing 122 includes an opening, or at least a portion that is formed of clear materials, to allow the user to view the level of the fluid 102 in the syringe 104, the compression of the compressible member 140, or other component of the syringe press 100.
As mentioned above, the caps 130 and 132 may attach to a body 134 of the housing 122 using conventional techniques. For instance, one or both of the caps 130 and 132 may be screwed onto the body 134, adhered to the body 134 using an adhesive, or attached to the body 134 using another suitable technique. In some embodiments, the housing 122 utilizes a bayonet mount to attach the caps 130 and 132 to the housing body 134. In some embodiments, the bayonet mount includes one or more pegs 160 located at the ends of the housing body 134, the pegs 160 are received within a slot 162 of the caps 130 and 132 to secure the caps 130 and 132 to the housing body 134.
As mentioned above, in some embodiments, the compressible member 140 comprises a spring, as shown in FIG. 2. In some embodiments, the syringe press 100 includes a cylinder 164 to maintain the orientation of the spring 140 with the longitudinal axis 124. In some embodiments, the cylinder 164 may be a cylinder of a syringe 166. Washers 168 may be positioned at opposing ends of the spring 140 to provide desired spacing or a uniform surface against which a compressive force stored within the spring 140 may be applied.
In some embodiments, a piston 170 of the syringe 166 is received within the cylinder 164. A compressive force stored within the spring 140 in response to the manual operation of the compression mechanism 142, drives the piston 170 to apply a compressive force to the syringe 104 containing the fluid 102 to drive the fluid 102 through the output 114. In some embodiments, stiffening members 171, such as carriage bolts or rods are inserted around the piston 170 of the syringe 166 to stiffen the piston 170, as indicated in FIG. 2. In some embodiments, washers 172 and 174 may be positioned between a flange 176 of the piston 170 and the flange 146 of the piston 108 of the syringe 104 to provide desired spacing between the components and/or ensure that the piston 170 remains in substantial alignment with the longitudinal axis 124 of the housing 122.
In some embodiments, the compression mechanism 142 comprises a screw 180 and a threaded member 182. The threaded member 182, such as a brad hole, is attached to the housing 122, such as the cap 132, and receives the elongated screw 180. A knob 184 may be attached at an end 186 of the screw 180 using a brad hole 188 or other suitable technique. This attachment of the knob 184 to the screw 180 causes the screw 180 to rotate with rotation of the knob 184.
In some embodiments, the screw 180 extends through the threaded member 182, and an end 190 of the screw 180 is attached to a component 192, which is configured to deliver the compressive force to the compressible member 140 and the syringe 104. In some embodiments, the component 190 comprises a cap 194 and a threaded member 196, such as a brad hole, which is attached to the cap 194. A washer 198 may be used to ensure proper transfer of the compressive force from the component 192 to the cylinder 164 of the syringe 166. The end 190 of the screw 180 is screwed into the threaded member 196 to attach the cap member 194 to the screw 180. In some embodiments, the cap 194 and the attached threaded member 196 rotate along with rotation of the screw 180. The washer 198 assists in reducing friction between the component 192 and the end 200 of the syringe 166. In some embodiments, the cap 194 distributes the compressive force generated by the compression mechanism 142 around the perimeter of the cylinder 164.
In operation, an operator positions the syringe 104 within the housing body 134 such as through the removal of the cap 130 or the cap 132. The compressible member 140 comprising the spring 140, the cylinder 164 and the piston 170 is assembled and inserted in the housing body 134. The cap 132 is then secured to the housing body 134.
The operator next rotates the knob 184 to drive the component 192 against the end 200 of the syringe 166. This generates a compressive force that is applied to the compressible member 140, the piston 108 and the cylinder 106 between the ends 126 and 128 of the housing 122. The compressive force compresses the spring 140 along the longitudinal axis 124 to store the compressive force for use over the discharge period. The compressive force drives the piston 108 into the cylinder 106 and drives the fluid 102 through the output 114, as described above. In some embodiments, the output 114 is fluidically coupled to a filter 116 or other medium through which the discharged fluid 102 is driven to form the filtered fluid 118.
Additional embodiments of the invention are directed to a method for delivering fluid from a syringe, such as syringe 104, using the syringe press 100 formed in accordance with one or more embodiments described herein. FIG. 3 is a flowchart illustrating the method in accordance with embodiments of the invention.
At 210 of the method, the syringe 104 is placed between first and second ends 126 and 128 of a housing 122 of the syringe press 100. At 212, a compressive force is applied along a longitudinal axis 124 of the housing 122 to the piston 108, the cylinder 106, and a compressible member 140 supported by the housing between the first end 126 and the piston 108, using a compression mechanism 142. At 214, the piston 108 is driven into the cylinder 106 and fluid 102 is driven through an output 114 of the cylinder 106.
In some embodiments, the compressible member 140 is compressed in response to the compressive force. After this compression, the compressible member 140 is allowed to expand over a period of time. In some embodiments, the piston 108 is driven into the cylinder 106, and the fluid 102 is driven through the output 114 of the cylinder 106 over a period of time (i.e., discharge period) in response to the expansion of the compressible member 140. In some embodiments, this period of time comprises 10 or 15 minutes.
In some embodiments of the method, the fluid 102 is driven through a filter 116 in response to the driving of the fluid 102 through the output 114 of the cylinder 106. In some embodiments, the filtered fluid 118 is collected in a container 120, as shown in FIG. 1.
In some embodiments of the method, the syringe press 100 is supported above the container 120 using a ring stand 216 or other suitable device, as shown in FIG. 1. In some embodiments, the ring stand 216 includes a base 218 that supports a pedestal 220. A clamp or arm 222 extends from the pedestal 220 and holds the housing 122 of the syringe press 100 above the container 120, as shown in FIG. 1.
In some embodiments, the compression mechanism 142 comprises an elongated screw 180 and a threaded member 182, which is attached to the housing 122 and receives the elongated screw 180, as shown in FIG. 2. In some embodiments of the method, the compressive force is applied by rotating the elongated screw 180 relative to the threaded member 182. In some embodiments, this is accomplished by rotating a knob 184 that is secured to the screw 180, as discussed above.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

What is claimed is:

1. A syringe press for driving a fluid from a syringe, which includes a cylinder configured to contain a fluid, and a piston having a seal configured to move within the cylinder, the syringe press comprising:

a housing having a longitudinal axis, a first end and a second end, the housing configured to support the syringe between the first and second ends;

a compressible member supported by the housing between the first end and the piston; and

a compression mechanism supported by the housing and configured to apply a compressive force to the piston, the cylinder and the compressible member, between the first and second ends and along the longitudinal axis;

wherein the piston is driven into the cylinder and fluid is driven through an output of the cylinder responsive to the compressive force.

2. The syringe press of claim 1, wherein the compressive force is applied to the piston and the cylinder through a first abutting surface abutting an end of the piston, and a second abutting surface abutting an end of the cylinder adjacent the output.

3. The syringe press of claim 2, wherein the output of the cylinder extends through an opening in the second end of the housing.

4. The syringe press of claim 1, wherein the compressible member stores the compression force and applies the compression force over a period of time to the piston and cylinder to drive the fluid through the output.

5. The syringe press of claim 4, wherein the compressible member comprises a spring.

6. The syringe press of claim 1, wherein:

the compression mechanism comprises an elongated screw and a threaded member, the threaded member is attached to the housing and receives the elongated screw;

the compressive force is generated in response to rotation of the screw relative to the threaded member.

7. The syringe press of claim 6, wherein compression mechanism comprises a knob attached to a first end of the screw, and an abutting member attached to a second end of the screw that abuts an end of the compressible member.

8. A method for driving fluid from a syringe, wherein the syringe comprises a cylinder for containing a fluid and a piston having a seal configured to move within the cylinder, the method comprising:

placing the syringe between first and second ends of a housing;

applying a compressive force to the piston, the cylinder, and a compressible member supported by the housing between the first end and the piston, between the first and second ends and along a longitudinal axis of the housing using a compression mechanism; and

driving the piston into the cylinder and driving fluid through an output of the cylinder responsive to applying a compressive force.

9. The method of claim 8, further comprising:

compressing the compressible member in response to the compressive force;

expanding the compressible member over a period of time; and

driving the piston into the cylinder and driving fluid through an output of the cylinder over the period of time responsive to expanding the compressible member.

10. The method of claim 9, wherein the period of time comprises 10 minutes.

11. The method of claim 10, wherein the period of time comprises 15 minutes.

12. The method of claim 8, further comprising driving the fluid through a filter responsive to driving fluid through an output of the cylinder.

13. The method of claim 12, further comprising collecting the filtered fluid in a container.

14. The method of claim 13, further comprising supporting the housing, the syringe, the compressible member and the compression mechanism above the container.

15. The method of claim 8, wherein:

the compression mechanism comprises an elongated screw and a threaded member, the threaded member is attached to the housing and receives the elongated screw; and

applying a compressive force to the piston comprises rotating the elongated screw relative to the threaded member.