Abstract:
A system for collection of blood during surgery includes an interlock that requires conduits supplying collected blood to a bag to be properly connected before the system is operated. The interlock includes a source of electromagnetic energy that illuminates connectors to determine whether they are connected. In a preferred embodiment, the connector is a Luer connector with a cylindrical portion that redirects the electromagnetic energy when the connector is in place.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of provisional patent applications 60/008,127 filed Oct. 20, 1995; 60/008,128 filed Oct. 20, 1995; 60/005;772 filed Oct. 20, 1995; and 60/020,754 filed Jun. 28, 1996. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to the art of systems for the collection of fluids. In particular, the invention relates to a bag for receiving fluids and a connector for connecting the bag to a supply pump. 
     BACKGROUND 
     It is known to collect fluids in containers such a flexible bags. For example, it is known to collect blood and other physiological fluids during surgery by pumping the blood into flexible bags. The fluids are then redelivered to the patient after processing. The fluids generally include debris that must be removed, and filters are used for this. Prior bags that include filters have not been effective, however, and are often expensive. Moreover, because the bags are disposable, the fluid lines are detachable, and it is necessary to provide an effective means for ensuring that the lines are properly connected before the pumping operation begins. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, a novel bag includes an internal filter, and a connector for attaching the bag to a fluid supply ensures that the bag is properly connected prior to operation of the pump. 
     The bag for receiving physiological fluids that have been recovered from a patient includes a filter for removing particles that are larger than a predetermined size. In the preferred embodiment, the filter is a 40μ mesh. The bag is made of two layers of flexible plastic with the filter held between the two layers. The inlet to the bag is placed between the filter and one of the outer layers, and the outlet is placed between the filter and the other of the outer layers. The flexible plastic layers and the filter are bonded together by heat, radio frequency (RF), or ultrasonic welding at the edges. 
     The edges are bonded in two locations. First, the filter and the outer layers are bonded completely around the bag inward of the outer edge of the bag, except for the locations where the inlet and outlet are secured. Then, the two outer layers and inlet and outlet conduits are bonded without the filter between them. By this construction, the bond of all three layers positions the filter to separate the bag into two compartments, and the outer bond acts as a safeguard to ensure that the contents are not spilled even if the inner bond fails. 
     In accordance with another aspect of the invention, a fluid supply line is connected to one or more lines, preferably inlet lines to the bag described above, by a verification connector. The verification connector includes means for verifying that the lines are properly connected and for controlling an interlock that prevents operation of the fluid pumps if the lines are not connected. The verification elements are easily attached to a base unit for cooperation with verification elements on the base unit to verify that the supply line is properly connected to the outlet lines. In the absence of such verification, operation of the fluid supply pump is inhibited. The verification connectors preferably include known Luer connectors for connecting the supply line to the inlet lines. Other types of connectors may, of course, be used. 
     In the preferred embodiment, the verification elements are optical. A light emitting diode, preferably infrared, and a photo detector, also preferably infrared, are contained in the base unit and are located with respect to the verification elements such that a beam from the light emitting diode will enter a transparent, conducting, portion of the verification elements when properly installed. The inlet line verification element will refract the light through an angle that will cause it to impinge on a detector in the base unit. Reflecting surfaces may be used to direct the incident and refracted beams to desired locations in the base unit. Signals from the photo detector are supplied to a control circuit that allows operation of a fluid supply pump only when the outlet lines are properly connected. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of a filter bag, partially broken away, in accordance with the invention. 
     FIG. 2 is a cross-section taken along line  2 — 2  of FIG.  1 . 
     FIG. 3 is a cross-section taken along line  3 — 3  of FIG.  1 . 
     FIG. 4 is a cross-section taken along line  4 — 4  of FIG.  2 . 
     FIG. 5 is a cross-section taken along line  5 — 5  of FIG.  2 . 
     FIG. 6 is a perspective of a male Luer connector with a mounting key attached. 
     FIG. 7 is a perspective of a base element having verification components in accordance with the invention. 
     FIGS. 8A and 8B are front views of the base element illustrating attachment of the mounting key to the base element. 
     FIGS. 9 a  and  9 B illustrate the operation of the verification elements. 
     FIG. 10 is a perspective showing the fluids lines properly connected and attached to the base element. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIG. 1, a filter bag  200  is constructed of respective outer sheets  202  and  204 . These sheets are preferably flexible and may be made of known plastic material. An inner sheet  206  is a filter, which is preferably a 40μ mesh of plastic material that can be easily bonded to the outer sheets. The bag includes an opening  208  to allow it to be hung from a variety of locations, such as a known I.V. stand. 
     The bag includes an inlet line  210  and an outlet port  212 . The inlet line  210  includes a Luer connector  214  for attaching the line to a source of the physiological fluid, such as the supply line shown in FIG.  6 . This connector is preferably designed to connect with other Luer connectors of standard size but also includes means for verifying whether the line is connected to a source of supply. While this verification element may take various forms, both electrical and mechanical, in the preferred embodiment the verification means is a cylindrical optical element  216 . The cylinder is transparent to light, for example, infrared light from a light emitting diode. When the Luer connector is properly attached to the source of supply, the light passes through the cylinder and is refracted thereby to impinge on a detector. An electronic control circuit senses the presence of light on the detector and, in response, allows activation of a supply pump. This ensures that the line is connected to the source of supply, preventing inadvertently spilling the physiological fluids. 
     The preferred construction of the filter bag is more clearly shown in FIG.  2 . The three layers of material, the two outer sheets  202 ,  204  and the filter  206 , are bonded together at an inner bond  218 . This bond, which may be produced by heating, radio frequency (RF), ultrasound, or other known methods, secures the three layers together to form two chambers  220  and  222  separated by the filter  206 . A second, outer bond  224  is formed at the outer edge of the bag. This outer bond is between only the two outer sheets and excludes the filter material. The outer bond  224  provides an additional measure of safety to prevent separation of the two sheets and accidental discharge of the contents of the bag, should the inner bond fail. This is important in situations, such as pressure infusion, where the contents of the bag are subjected to pressures as high as 300 mmHg to increase the flow rate. 
     FIGS. 4 and 5 show how the sheets  202  and  204  and the filter  206  are secured to the inlet line  210  and the outlet  212 . It will be appreciated that the inlet and outlet could as well be attached by a variety of means. For example, these could be provided by a known sidewall connector in each of the sheets  202  and  204 . 
     In operation, physiological fluid, such as blood obtained from a surgical site, is supplied to the inlet line  210  by a pump (not sown). This fluid first flows through the inlet line  210  into the chamber  222 . As the fluid passes through the filter into chamber  220 , the filter removes unwanted particles. As the bag continues to fill, some of the fluid will remain in chamber  222 , while the remainder will pass through the filter to chamber  220 . When it is desired to use the fluid in the bag, an appropriate outlet line (not shown), such as an I.V. line is attached to the outlet  212  to permit fluid to flow out of the bag. Preferably, outlet  212  is a known spike port that has a removable cover  226  and receives a spike in known fashion. 
     The spike port includes a flange  228 , which may be used to support the bag while it is being filled. When the fluid in the bag is withdrawn, the bag is hung from the opening  208 , and the inlet line  210  is closed with a slide clamp, metal crimp, Luer cap, or the like. Thus, the bag is filled in an orientation opposite from the orientation from which it is emptied. This increases efficiency by providing even usage of the filter layer; the in-flowing fluid will pass continuously through one end of the filter as it is filling and the out-flowing fluid will continuously pass through the opposite end of the filter as it is being discharged. 
     With reference to FIG. 6, a male Luer connector  302  is attached to a tube  304 , as known in the art. A mounting key  306  according to the invention is attached to the Luer connector, as by welding or cement. The key is used to secure the male connector to the base element shown in FIGS. 7 through 10. The base element  308  is attached to, or is a part of, apparatus for pumping fluids into a bag, such as bag  200 . The base element includes a face plate  310  for receiving the key  306  and the Luer connector. The face plate includes an opening  312 , which is of a shape that will allow the key to be inserted. A narrower notch  314  is located below the opening  312 , and a slot  316  is formed between the front of the faceplate and a rear wall thereof. Slot  316  extends vertically from the bottom of the opening  312  to just above the bottom of the faceplate. While the key has been shown to be square, other shapes are possible. 
     The installation of the key will be explained with reference to FIGS. 8A and 8B. The key  306  with the male Luer connected is first inserted in the opening  312  as shown in FIG.  8 A. Then, the key is slid downward as illustrated in FIG. 8B, whereby the edges of the key engage the slot  316  to thereby secure the male Luer and key in the faceplate  310 . The key is preferably retained in the position shown in FIG. 8B by gravity; as well the position may be maintained by friction or other mechanisms. 
     The purpose of this structure is to provide verification of the proper installation of the Luer connectors. Thus, base element  308  includes a source  318  of electromagnetic energy, such as infrared energy from a light emitting diode. The base also includes a window  320  for allowing refracted energy to impinge on a detector  322 . The detector is shown located behind the window, but it could be placed in the element  308  as well. Also, reflectors could be employed to direct the beams as desired to detectors located elsewhere. 
     FIG. 9A illustrates the situation when the female Luer connector  214  is attached to the male Luer connector  302 , and the key  306  is secured in the faceplate  310 . In this configuration, the light beam  324  is refracted by the optical element  216  on the female Luer. Thus, the light path is as shown in FIG. 9A where is passes through window  320  and impinges on detector  322 . The detector  322  supplies a signal to a control circuit allowing the pumps to operate. 
     FIG. 9B illustrates the situation where the female Luer is not properly connected. In this situation, the required refraction does not occur, and the beam does not pass through the window  324 . Accordingly, the detector  322  does not detect the impingement, and the control circuit does not enable operation of the pumps. 
     FIG. 10 shows the male and female Luer connectors attached to each other and installed on the base element. The base element provides an opening at the bottom for receiving the line  304  from the source of fluid, such as a pump. The line  304  and key may be installed from the front of the base element prior to connection of the line  210 . Or, the two lines may be attached and then installed in the base element. One advantage of the key, however, is that the connector  214  may be easily attached to the connector  302  with one hand when the key is secure in the base element. 
     While any number of inlet lines  210  may be used, only one is illustrated in the figures. Thus, supply line  304  may be connected to a Y-connector (not shown), which is in turn connected to the supply pump 
     As described above, each of the inlet lines  210  includes a female Luer connector  214  that has been modified to include a verification element. The verification element in the preferred embodiment is the optical element  216  that cooperates with the light source and detector in the base element to verify that the connector  214  is properly in place. 
     It will be appreciated that the described verification system is fail-safe because it requires a predetermined signal to be received by the photo detectors before connection is verified. If the Luer connectors are not in place, the light from the source in the base unit will not be refracted to the photo detectors, and verification will be precluded. Modifications within the scope of the claims will be apparent to those of skill in the art.