PERISTALTIC PUMP WITH A REMOVABLE CASSETTE
A peristaltic pump is provided which includes a removable cassette that can be mounted to the peristaltic pump using a single hand of a user. The peristaltic pump includes, a pump frame, a plurality of rollers configured to mount to the pump frame, an actuator operably coupled to move the plurality of rollers, and the removable cassette The cassette includes a cassette frame and a cam positioned to compress a tube against the plurality of rollers. The cassette is mountable to the pump frame by applying pressure in a first direction to the cassette frame and is dismountable from the pump frame by applying pressure in the first direction to the cassette frame. In an exemplary embodiment, a pin mounts to the pump frame and the cassette frame includes a ramp configured to receive the pin so that the pin is held in a seat of the ramp.
This application is a continuation application of International Application No. PCT/FR2005/001479 filed on Jun. 14, 2005, the entire disclosure of which is incorporated herein by reference, which claims the benefit of French Patent Application No. 04/06767 that was filed Jun. 22, 2004, the entire disclosure of which is incorporated herein by reference.
FIELDThe field of the disclosure relates generally to peristaltic pumps. More specifically, the disclosure relates to cassettes that are readily attached and detached from the pump.
BACKGROUNDPeristaltic pumps have been known for many years, and are commonly used for medical and research purposes. Peristaltic pumps move a liquid through a tube without any part of the pump ever touching the liquid. As a result, it is possible to pump liquids, such as blood, which are sensitive to external contamination. Typically, a pump comprises rotating rollers that compress a part of the flexible tube as they move, which propels the liquid through the tube.
For example, such a pump is described in document EP 339 857, the entire disclosure of which is incorporated herein by reference. The flexible tube must withstand the compressive force while remaining leak proof. The pump in the aforesaid document includes removable cassettes that each include a tube and a means for securing the cassettes to the pump frame so that the tube is held against the rollers to ensure good contact between tube and rollers. The means described for securing the cassettes include a notch and cam arrangement which requires two hands to operate a release lever to unlock the cassette from the pump. Additionally, a second hand simultaneously holds the cassette to prevent it from jumping off of the frame What is needed is a peristaltic pump cassette which may be easily mounted to and dismounted from a peristaltic pump using a single-hand.
SUMMARYA mechanism for mounting and dismounting a removable cassette from a peristaltic pump is provided. The removable cassette is easily mounted to a pump frame of the peristaltic pump using a single-hand of a user. Additionally, a similar motion both mounts the cassette to the pump frame and dismounts the cassette from the pump frame.
In an exemplary embodiment, a peristaltic pump includes, but is not limited to, a pump frame, a plurality of rollers configured to mount to the pump frame, an actuator operably coupled to move the plurality of rollers, and a cassette. The cassette includes a cassette frame and a cam positioned to compress a tube against the plurality of rollers. The cassette is mountable to the pump frame by applying pressure in a first direction to the cassette frame and is dismountable from the pump frame by applying pressure in the first direction to the cassette frame.
In another exemplary embodiment, a method of using a cassette in a peristaltic pump is provided. A cassette frame of a cassette is positioned for mounting to a pump frame of a peristaltic pump. A hook is engaged in a notch to mount a first end of the cassette frame to the pump frame. A pin slides in a first direction to accept a second end of the cassette frame. The pin slides along a ramp and is held in a seat of the ramp to mount the cassette to the peristaltic pump.
Other principal features and advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGSExemplary embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like numerals denote like elements.
While a single style of cassette has been illustrated in the figures, a plurality of cassettes similar in construction to that described are contemplated. For the purposes of this disclosure and unless otherwise specified, “a” or “an” means “one or more”
With reference to
In the exemplary embodiment of
The actuator is operably coupled to rotate the plurality of rollers 16. For example, the actuator may include a rotor connected to the plurality of rollers through a shaft 11 as known to those skilled in the art. The actuator may be any device as known to those skilled in the art for causing rotation of the plurality of rollers. Exemplary actuators include an electric motor, a servo, stepper, or piezo motor, a pneumatic actuator, a gas motor, etc.
Front wall 10 and back wall 8 define between them a cassette housing 12 sized to accommodate one or more removable cassettes 6. Front wall 10 and back wall 8 are linked together by a first brace 40 and a second brace 42 which extend parallel to the axis of symmetry 7, and act as a support and locking mechanism for the removable cassette(s) 6. With reference to
With reference to
The removable cassette 6 includes a cam 30 accommodated in cavity 29. Cam 30 has an essentially flat rectangular shape with a saddle-shaped hollow formed by a lower edge designed to face the plurality of rollers 16. The front wall 21 and the back wall 25 partially cover each side of cam 30.
With reference to
The removable cassette 6 mounts to the peristaltic pump head 2 at the ends of legs 24 adjacent to slots 26. For example, as shown in
The aperture 60 allows the pin 50 to slide back and forth, along a longitudinal axis of the pin 50, while being retained within first brace 40 by a retaining clip 63. The retaining clip 63 has a shape that is complementary to that of cavity 67. The retaining clip 63 includes a fork 68 through which the distal end 54 of the pin 50 is inserted such that the fork 68 maintains the head 56 of pin 50 within the aperture 60. The retaining clip 63 also has a leaf spring 66 which exerts a force on head 56.
When a force is applied to the distal end 54 of the pin 50 in a direction parallel to the longitudinal axis of the pin 50, the pin 50 is pushed against leaf spring 66 and into first brace 40 (
The aperture 60 allows the pin 50 to pivot freely within the aperture 60 around an axis 64, indicated in
As used herein, facet is used to refer to an area that may be flush, but of a different plane than that of an adjacent area (e.g.
The form and function of the various elements of the peristaltic pump 2 and a removable cassette 6 will be more apparent using a description of a method for mounting and dismounting the removable cassette 6.
The hook 44 of one of the legs 24 of removable cassette 6 is engaged in the notch 46 of the second brace 42. The ramp 52 of the removable cassette 6 is brought into close proximity with the distal end 54 of pin 50. As pressure is applied to the cassette body 20, tube 22 is compressed, and the distal end 54 of pin 50 enters the ramp 52 at area 70. As pressure is continuously applied, the distal end 54 of pin 50 follows a course in which the distal end 54 of pin 50 initially encounters facet 71 and enters launching area 78, the “highest” or shallowest portion of ramp 52. A wall 92 on relief area 71 aids in guiding the distal end 54 to the launching area 78. Pressure is continuously applied to the cassette body 20 until the distal end 54 encounters a wall 80 that prevents further travel in such a direction. As the pressure is released, the compression of tube 22 recoils the removable cassette 6 in a reverse direction launching the distal end 54 over facet 72 from the launching area onto a seating area 82 and into a seat 84, thus securing the removable cassette 6 within the cassette housing 12.
As the distal end 54 of pin 50 enters area 70 of the ramp 52, the contact of the distal end 54 with the area 70 of the ramp 52 causes the pin 50 to move in a longitudinal direction toward the cavity 67 of the first brace 40, thus tensioning leaf spring 66 against head 56 and about axis 62. As the distal end 54 moves from areas of higher relief in the ramp 52 to those of lower relief, the leaf spring 66 exerts a force on pin 50 causing the distal end 54 to remain in contact with the ramp 52.
When dismounting the removable cassette 6 from the cassette housing 12 is desired, pressure is again applied to the cassette body 20, with facet 72 preventing “reverse” travel of the distal end 54, and encouraging “forward” travel of the distal end 54 over facet 73, onto landing area 86 as tube 22 is compressed. A wall 88 prevents further compression of the tube 22. As pressure is once again released, the tube 22 exerts a recoil force in the direction opposite to the applied pressure, with the distal end 54 traveling through exit area 90, thus dismounting the removable cassette 6 from the cassette housing 12.
The motions required to mount and dismount removable cassette 6 from the peristaltic pump head 2 may be performed by a single hand of a user and are ergonomically efficient. The pivoting of the pin 50 in aperture 60 allows for lateral travel of the removable cassette 6 during insertion and removal. A user can pivot the dismounted removable cassette 6 to separate the released leg 24 from the first brace 40, and then separate the hook 44 from the second brace 42 to remove the cassette from its support.
Therefore, the presently embodied removable cassette and pump frame allows the user to mount the removable cassette 6 onto the peristaltic pump head 2 by simply applying pressure to the top of the removable cassette 6. The same action allows the user to dismount and remove the removable cassette 6. These actions can therefore be performed simply and quickly and, if required, one after the other or even simultaneously for several of the pump's cassettes.
It should be noted that these operations are accomplished without the user ever touching the tube. These operations use the compressibility and recoil of the tube to define limit positions, which prevent undue action on the tube both during these operations and when the cassette is in its functional position on the pump head. In particular, there is no risk that the tube will be excessively stressed during these operations. This is particularly important to prolong the lifetime of the tube. Typically, the lifetime of a peristaltic pump tube is directly impacted by the pump's operation. As a result, the lifetime of the peristaltic pump tube may be considerably reduced if overly stressed.
While some embodiments have been illustrated and described, it should be understood that changes and modifications can be made in accordance with ordinary skill in the art without departing from the invention in its broader aspects as defined in the following claims. For example, the relative positions of a hook and a notch may be reversed such that the hook is associated with a brace and the notch is associated with a leg of the removable cassette and/or the relative positions of a pin and a ramp may be reversed such that the ramp is associated with a brace and the pin is associated with a leg of the removable cassette.
The foregoing description of exemplary embodiments of the invention have been presented for purposes of illustration and of description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and as practical applications of the invention to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents
Claims
1. A peristaltic pump, the peristaltic pump comprising:
- a pump frame;
- a plurality of rollers configured to mount to the pump frame;
- an actuator operably coupled to move the plurality of rollers;
- a cassette, the cassette comprising a cassette frame; and a cam positioned to compress a tube against the plurality of rollers; wherein the cassette is mountable to the pump frame by applying a first pressure in a first direction to the cassette frame and is dismountable from the pump frame by applying a second pressure in the first direction to the cassette frame.
2. The peristaltic pump of claim 1, wherein the cassette comprises a hook extending from the cassette frame and further wherein the pump frame comprises a notch configured to receive the hook.
3. The peristaltic pump of claim 1, wherein the pump frame comprises a hook and further wherein the cassette frame comprises a notch configured to receive the hook.
4. The peristaltic pump of claim 1, further comprising a pin mounted to the pump frame, wherein the cassette frame comprises a ramp configured to receive the pin.
5. The peristaltic pump of claim 1, further comprising a pin mounted to the cassette frame, wherein the pump frame comprises a ramp configured to receive the pin.
6. The peristaltic pump of claim 4, wherein the pin comprises:
- a cylindrical body; and
- a head extending from the cylindrical body at a first end.
7. The peristaltic pump of claim 6, wherein the pin further comprises a parallelepiped housing surrounding a portion of the cylindrical body.
8. The peristaltic pump of claim 7, wherein the pump frame further comprises an aperture configured to accept the parallelepiped housing of the pin.
9. The peristaltic pump of claim 6, wherein the pump frame further comprises an aperture configured to accept the pin.
10. The peristaltic pump of claim 9, wherein the aperture is sized and shaped either to allow sliding of the pin within the aperture, to allow pivoting of the pin within the aperture, or to allow sliding and pivoting of the pin within the aperture.
11. The peristaltic pump of claim 10, wherein the pivoting of the pin is about an axis perpendicular to a direction of sliding of the pin within the aperture.
12. The peristaltic pump of claim 10, wherein the ramp comprises a seat configured to hold the pin during mounting of the cassette to the pump frame.
13. The peristaltic pump of claim 12, wherein the ramp comprises a plurality of levels configured to guide the pin toward the seat during mounting of the cassette to the pump frame.
14. The peristaltic pump of claim 12, wherein the ramp comprises a plurality of levels configured to guide the pin away from the seat during dismounting of the cassette from the pump frame.
15. The peristaltic pump of claim 9, further comprising a biasing member mounted to resist sliding of the pin within the aperture.
16. A method of using a cassette in a peristaltic pump, the method comprising:
- positioning a cassette frame of a cassette for mounting to a pump frame of a peristaltic pump;
- engaging a hook in a notch to mount a first end of the cassette frame to the pump frame;
- sliding a pin in a first direction to accept a second end of the cassette frame;
- sliding the pin along a ramp; and
- holding the pin in a seat of the ramp to mount the cassette to the peristaltic pump.
17. The method of claim 16, further comprising:
- applying pressure to the cassette frame in a second direction thereby releasing the pin from the seat;
- sliding the pin along the ramp; and
- disengaging the hook from the notch to dismount the cassette from the peristaltic pump.
18. The method of claim 17, wherein the second direction is generally perpendicular to the first direction.
19. The method of claim 16, wherein the cassette comprises the hook which extends from the cassette frame and further wherein the pump frame comprises the notch.
20. The method of claim 16, wherein the pin mounts to the pump frame and further wherein the cassette frame comprises the ramp.
Type: Application
Filed: Dec 21, 2006
Publication Date: Sep 13, 2007
Inventors: Claude Voyeux (Goussainville), Mustapha Mazouzi (Velizy)
Application Number: 11/614,177
International Classification: F04B 43/12 (20060101);