Filtration System Preparation of Fluids for Medical Applications
Systems, methods, and devices for preparation of water for various uses including blood treatment are described. In embodiments, fluid is passed either by pump or passively by gravity feed, through various filtration elements from a fluid source to a treatment fluid container. The latter forms a batch that may be used during treatment. The advantage of forming the batch before treatment is that the rate of filtering needn't match the rate of consumption during treatment which provides multiple benefits and liabilities to overcome, as discussed herein. Mechanisms for preparing pure water for infusion or medicaments are described such as elimination of chlorine and colloidal aluminum. Also various control mechanisms to help avoid contamination are describe.
Many medical applications require purified water and other fluids. for example, hemofiltration, tissue irrigation, and hemodiafiltration. Some prior art systems have focused on continuous purification processes that require a separate dfiltration/purification apparatus that must be periodically purged and verified to provide sufficient constant flow of sterile replacement fluid. (See Chavallet U.S. Pat. Nos. 6,039,877 and 5,702,597.) Such devices are necessarily complicated and require separate pumping systems for the purification process. In addition, the rate of supply of fluid for such systems is very high, requiring expensive filters to be used. The same high-rate problem exists for the generation of replacement fluid for hemofiltration, and therefore also requires expensive filtering apparatus.
Large and small scale inline systems are known for preparation of infusible fluids and for preparation of dialysate. The following prior art references discuss examples of such systems.
US Patent Publication No. 2004/0232079
US Patent Publication No. 2003/0105435
U.S. Pat. No. 5,645,734
U.S. Pat. No. 5,782,762
U.S. Pat. No. 6,136,201
PURELAB Maxima, Ultra-Pure Water Purification Systems
Shipe, Brad; “The Case for UV in Dechlorination Applications,” Water Conditioning & Purification Magazine, January 2003, Vol 45 No. 1.
The present disclosure relates to apparatus, methods, devices, articles of manufacture, etc. for producing pure water and, in some embodiments, pure solutions. These may be used for the preparation of solutions for medical applications such as tissue irrigation, preparation of pharmaceutical, blood treatments such as hemofiltration, hemodialysis, hemodiafiltration and ultrafiltration, and other treatments.
As described in
Between the first and second filter stages 410A and 410B, a water quality sensor 405 is provided. In an embodiment, the water quality sensor 405 is a conductivity or resistivity probe that detects ionic species in the water after passing through the first stage filter 410A. In a preferred embodiment, the second stage 410B provides at least some redundancy in that the second stage 410B provides some of the filtration effect of the first stage 410A. In an alternative embodiment it provides all of the filtration of the first stage 410A and is thereby completely redundant. In such an arrangement, the first stage would expire (become depleted), allowing contaminants to break through, before the second stage expires. The contaminant breakthrough is detected by a controller 415 connected to the water quality sensor 405. The controller 415 also controls the pump 416. Upon expiration of the first stage 410A, the controller allows the preparation to continue until a certain amount of fluid is collected in batch container 417, preferably an amount required for a treatment. Once this threshold quantity is delivered, the controller will not allow the pump 416 to be started until the filter module 425 is exchanged with a fresh one. The second stage filter 410B, preferably, is sized to ensure that, by itself, it can purify at least a single batch of water, plus a safety margin without any contaminant breakthrough to the output line 404. In a preferred embodiment, the second stage filter 410B is a smaller size than the first 410A. In the preferred embodiment, the second stage filter 410B may be of a different type which may not be as able to handle high contamination loads as the first 410A. This may be acceptable because, although after breakthrough is detected, the emerging fluid is still substantially purified and the load input to the second stage filter 410B may remain low until a single batch of fluid is prepared.
In an alternative embodiment, the filter module 425 is provided with a permanently attached data carrier 423 such as radio frequency identification device (RFID), bar code (1- or 2-dimensional), contact-type identification device, etc. The data carrier 423 contains a unique identifier of the filter module. When a cartridge is connected to the pump, the controller 415 reads the data carrier 423 using a reader device 422 and stores the identifier in a memory 437. If the water quality sensor 405 indicates contaminant breakthrough, the controller permanently stores the identifier in an expired directory in the memory, which has a non-volatile portion for the directory. If a user attempts to connect a module 425 with an identifier stored in the directory, the controller will not operate the pump and will indicate the error condition by means of an annunciator 420 or equivalent device, such as an LCD display message.
Note that in an alternative device, the data carrier 423 is a programmable device with a writable memory. In this embodiment, the controller 415 programs the data carrier 423 with a flag indicating that the filter module 425 is expired. The controller 415 then prevents the initiation of a new batch.
Referring to
The special clamping connector 442 may any suitable device that seals off, to prevent contamination. An embodiment of such a connector is shown in
Returning to
Referring to
Referring to
Note that pressure indicators 1015 and 1025 may be pressure transducers that feed control signals to a control device such as discussed with reference to
Referring to
Note that instead of using layered beds in a single cartridge as described, separate cartridges each containing one of a SBA and SAC filter bed may be used. Also, each cartridge could contain more than one layer of each to provide similar results.
The resistivity probe 1022 detects ion concentration by contact testing of the resistivity of the water. A signal is generated to indicate that this will be the last allowed batch before the system will require the replacement of the replaceable module 910. Control may be provided as in the embodiment of
Note, it should be clear that resistivity probe 1022 may be used in a configuration such as that of
Note that two separately-housed ultrafilters 1035A and 1035B are serially interconnected. The separate housings ensure against failure mechanisms such as grow-through of pathogens, adjacent simultaneous or shared seal failure. For example, prior art reference US Patent Publication No. 2004/0105435, cited in the Background section, shows a filter cartridge with two microporous membranes in adjacent layers of a filter cartridge housing. These may share a seal mechanism or adjacent seals such that failure of the seal of one necessarily involves failure of the seal of the other. Also once a grow through problem occurs in one, the adjacency may cause the problem to creep directly into the adjacent membrane. These problems are prevented by the illustrated arrangement of separate redundant ultrafilters.
Note that the benefit of separately housed filters may be substantially provided in a single housing by substantially separating two ultrafilter layers. Referring to
Note the final conductivity/resistivity sensor/alarm 1025 may control the pump, as noted. A controller 1090 may be connectable to the disposable filter module 910 and configured to stop the pump 1020. The trigger resistivity safety level to cut-off the pump 1020 may be 1 megohm, but may be raised to 2 megohm to allow the use of required temperature compensated resistivity probes (an FDA & AAMI requirement) This does allow use of low cost in-line resistivity probes in the disposable filter module 910.
Preferably, the filter module 910 as well as the modules of other embodiments are of such a flow rate that upward flow of fluids is possible. Generally, prior art deionization beds suffer from the problem of floating or loosening resin particles which may have been disturbed during handling. The separation and floating of the particles breaks up the beds and renders the filters less effective. To avoid this, generally, filter systems are configured to direct flow downwardly through the beds to help keep and compress the resin particles. But if flow rates are kept low, as may be done in the present system, water may be flowed in an upward direction which helps to eliminate air from stream. Air is a notorious problem in the preparation of medicaments such as dialysate. The precise flow rates needed to allow upward flow will vary according to the characteristics of the system. One way to allow faster flow rates without being hampered by break away resin particles is to provide a bed compressor of resilient porous material to compress the bed. Referring momentarily to
The following is an example procedure for using the devices discussed with reference to
1. Remove the dialysate concentrate tubing set 915 and remove the cap 14 from the tubing line 7 that contains the filter 11. (The 0.22 micron filter 11 provides additional protection from inadvertent contamination.)
2. Connect the outlet line 404 to the concentrate bag luer connection 9.
3. Break the frangible luer connector 4 which connector is configured to form a permanent seal on the side facing the Y-junction 5 when disconnected.
4. Add predetermined quantity of water into the concentrate bag using the purification plant through tubing branch 7 through luer connector 9.
5. Optionally a user can write on the bag label the date and time water was first added to the concentrate bag, to assist in ensuring that it is used within a period of time. An automated scheme may be employed as well.
6. Shake the batch container 1 well to mix.
7. Confirm solution conductivity prior to use. Remove the break-off cap 1 and draw sample from this branch 15. After removing the sample, clamp the line using the pinch clamp 17 provided.
8. (The following is normative according to a preferred embodiment and not limiting of the invention) Conductivity must be in the range 13.0 to 14.4 mS/cm. Nominal conductivity for the dialysate solution is 13.7 mS/cm at 25° C. If conductivity does not meet this specification do not use it. Verify that the results are accurate. If conductivity is high additional water may be added to bring it within specification. If conductivity is low then the solution must be discarded.
9. Using the non re-opening clamp 13 provided, clamp the line that is connected to the water purification plant.
10. The clamp 6 is, next, clamped on the line that is connected to the dialysate bag 1.
11. Disconnect the water source at the luer connection 26.
12. Connect the bag of dialysate solution to the dialysis circuit at the connection 8. This leaves the filter 11 and permanent clamp 13 in place to protect the water supply source.
13. Unclamp the line going to the dialysate bag using clamp 6, and initiate treatment after verifying that dialysate will be used within 24 hours from when water was added.
Referring to
At 110, a fitting connecting a sample or feed line 145 is shown. The latter may be used, with a connector 156, connect a sampling syringe to draw out a sample of a medicament or infusate. A check valve may be provided at 155 to prevent ingress of contaminants. A clamp (not shown separately) may be provided as well to guard against contamination. In an alternative embodiment, line 145 may be configured for injecting a soluble concentrate into the batch container 100 before the container 100 is sealed and sterilized as a unit (for example, by gamma ray sterilization). When a prescribed quantity of purified water is added to the batch container, the diluted concentrate may form a medicament or infusate such as replacement fluid for hemofiltration or a dialysate for hemodialysis. Line 145 may also represent a draw line that may be connected to a treatment machine. In the latter case, a sterile filter (at 155), such as a microporous membrane of 0.2μ may be provided to guard against touch contamination. Additionally, a clamp may be provided as at 155.
In the embodiment of
Referring to
Referring to
A data carrier may include software and instructions for using the filter module 1125. These may be read by a permanent component of a filtering system as described in connection with
In an embodiment, features indicated at 301-306 may be added to allow the base unit 335 to control when and whether an outlet line of a batch container should be opened and clamped. A batch container is fitted in the station 305 and an outlet line of the batch container fitted between clamping portions 303 and 304. A detector 306 verifies that the line has been fitted in place. When the system is run, an actuator 302 and motor 301 may be activated to clamp the line during fluid purification and as the batch container is filled. After the batch is filled, the clamp may remain closed until a treatment operation, which may be run while the batch container remains in place, is begun. At treatment time, the clamp mechanism 303 and 304 can enforce the expiration time of the batch of fluid. For example, a timer can be started within the controller of the base unit or, equivalently, a time/date stamp stored and the clamp only released if the batch of fluid is used for treatment within a certain period of time. For this purpose a treatment machine and the base unit 335 may be combined into a single device under common control or the two may be linked by a data link to operate cooperatively to achieve such a result. The flow chart of
Referring now to
Referring to
A sample program for operating the various embodiments described herein is shown in
At step S55 depending on the type of data carrier (e.g., programmable or just carrying a unique ID), the expired or spent unit is indicated as expired so that reuse can be prevented. For example, in S55 the data carrier may be programmed with a token to indicate that the attached filter module is expired or a server may be sent a message to indicate that its unique ID should be added to a list of expired IDs. Any suitable device may be used to “expire” a unit. Since expiring a unit may still allow a batch to be prepared, control returns to S40. Completion of the treatment may be determined at step S45 by measuring the total mass pumped or by other means. For example, if the embodiment provides a conductivity probe in the batch container, step S45 may depend on the measured conductivity of the batch contents. Once completion is determined, the system may be halted at step S50 and the batch bag “stamped” with a time and date. Note that further instructions may be output at this point.
In one embodiment, the water purification and treatment may be done from a single apparatus and under common control. The steps following step S50 illustrate this. Assuming purified fluid has been added to a batch container of some description such as those described in the current specification or some other, the contents of the container may be mixed, if a solute is involved, and the contents checked in some way in step S51. For example, the conductivity of a mixed batch or the resistivity of a pure batch can be checked determine its conformity with treatment specifications. In step S52, if a value is out of range, control passes to step S30, but if not, the batch may be utilized at anytime up to an expiration time/date (MTU time, or Mixed Till Use-time). In step S53, an outlet clamp that prevents fluid from being drawn from the batch container is released to allow a treatment to be performed with the fluid product. At the same time, an acceptance message can be output to the user on a display. At this time, in S54, a time stamp is stored or a timer started to keep track of the expiration of the batch of fluid. If the expiration is not observed, which is tested at step S56 by checking to see if the timer has expired, the clamp will close in step S30 (under the general step indicated as “take action”) and an appropriate message output. The system will then wait until treatment is completed while, optionally, continuously checking the MTU timer in steps S46 and S56.
Note that many of the described mechanical and control features are novel and inventive alone, as subcombinations with other features and their description in combination in the above embodiments is not intended to be interpreted as limiting of the inventions disclosed herein. Referring to
Referring to
An alternative design that integrates air vent configurations into the housing of the ultrafilter 714 is shown in
Referring to
One of the drivers for the features discussed above is a need to provide pure water irrespective of input water quality. The above embodiments are not reliant upon water quality and are designed to reliably produce pure water or solutions regardless of input water quality. Various embodiments are also designed to reduce the costs associated with lower volume (10-60 liters) preparation of medical and other pure solutions and to maintain simplicity through the combination of semi-permanent and single-use modules which combine to eliminate the complexities, costs and safety issues associated with maintenance, sterilization, and operation of many other prior art systems.
Although the foregoing inventions have, for the purposes of clarity and understanding, been described in some detail by way of illustration and example, it will be obvious that certain changes and modifications may be practiced that will still fall within the scope of the appended claims. For example, the devices and methods of each embodiment can be combined with or used in any of the other embodiments. For another example, the air vents described can be of any suitable description and need not be membrane type air vents at all, although these are preferred.
Claims
1. A water treatment plant, comprising:
- a first purifying filter adapted to purify an input water stream and output a purified stream;
- a first microporous membrane ultrafilter effective to sterilize a water stream connected to receive said purified stream and further filter it;
- a second microporous membrane ultrafilter effective to sterilize a water stream connected in series after said first microporous membrane ultrafilter;
- said first and second microporous membrane ultrafilters each being contained in one or respective housings and having separate seals to said one or respective housings that are remote from each other;
- said first and second microporous membrane ultrafilters having surfaces that are separated by a substantial distance.
2. A plant as in claim 1 wherein said first and second microporous membrane ultrafilters are commonly housed in a single housing and separated by a spacer of porous inert material and sealed to said single housing by separate seals.
3. A controller device for a water treatment plant, comprising:
- a controller adapted to read a unique identifier of a connected filter and a fluid quality sensor reading;
- a pump;
- said controller being configured to continue pumping if, during a pumping operation, said fluid quality sensor gives a first indication indicating that said filter module is performing adequately;
- said controller being configured to continue pumping a until a predetermined quantity of fluid has been pumped if, during a pumping operation, said fluid quality sensor gives a second indication indicating that said filter module will fail imminently, but thereafter to not pump fluid if a same unique identifier is read as when said second indication was received by it or by another similar controller.
4. A controller as in claim 3, wherein said controller includes a data carrier reader to read said unique identifier stored in said data carrier attached to said module.
5. A controller as in claim 3, wherein said controller is configured to not pump fluid if a same unique identifier is read as when said second indication was received by it or by another similar controller by comparing a read identifier with a stored identifier in said controller or one read by said controller from a database of unique identifiers.
6. A water treatment plant comprising:
- a filter module including first and second filters connected in series and connectable to a supply of fluid;
- a pump;
- a controller with a fluid quality sensor connected thereto;
- said fluid quality sensor being connected to detect a quality of fluid between said first and second filters;
- a filter module detector connected to said controller configured to uniquely detect a filter module connected to said pump;
- said controller being connected to control said pump responsively to a signal from said fluid quality sensor and said module detector;
- said controller being configured to continue pumping if, during a pumping operation, said fluid quality sensor gives a first indication;
- said controller being configured to continue pumping a until a predetermined quantity of fluid has been pumped if, during a pumping operation, said fluid quality sensor gives a second indication, but thereafter to not pump fluid until said filter module is replaced with a different one not corresponding to said unique one.
7. A plant as in claim 6, wherein said first and second filters are deionizing filters and said fluid quality sensor is a conductivity sensor.
8. A plant as in claim 6 wherein said filter module detector is a reader for a data carrier.
9. A fluid container device, comprising:
- a sealed sterilized container with a conductivity sensor in communication with an interior of said container;
- at least one sealed connector adapted for adding fluid to said container,
- at least one sealed connector adapted for removing fluid from said container.
10. A device as in claim 9, wherein said conductivity sensor is contained in a test line in communication with said interior and adapted to be connected to a source of suction.
11. A device as in claim 9, wherein said conductivity sensor is contained in a test line in communication with said interior and adapted to be connected to a source of suction thereby to draw a sample of contents of said container.
12. A device as in claim 11, wherein said test line includes a check valve to prevent ingress of contaminants into said container.
13. A device as in claim 9, wherein said conductivity sensor is located within a cage inside said container, said cage being configured to prevent said container from isolating said sensor from fluid in said container proper.
14. A device as in claim 9, wherein said at least one sealed connector in adapted for adding fluid to said container includes an inline sterile filter.
15. A fluid container device, comprising:
- a sealed sterilized container with a conductivity sensor in communication with an interior of said container;
- at least a first sealed connector at the end of a first line adapted for adding fluid to said container, said first line having an inline sterile filter to prevent contamination of contents of said container when fluid is added thereto, said first line having a dual connector with two lumens, the first line being connected to a first of said two lumens and said connector being connected to a second of said two lumens, said dual connector having a removable seal.
16. A device as in claim 15, further comprising at least a second sealed connector adapted for removing fluid from said container.
17. A water treatment plant for preparing a batch of treatment fluid for use in extracorporeal blood treatment, said plant including a strong acid cation fand strong base anion in such a configuration as to substantially eliminate reduce colloidal aluminum (Alum) to soluble aluminum in a succeeding deionization filter.
18. A water treatment plant for preparing treatment fluid for use in extracorporeal blood treatment, said plant including a resistivity monitor that is configured to shut a pump down when resistivity falls below a predetermined conductivity.
19. A plant as in claim 18, wherein said predetermined conductivity is about 2 megohms.
20. A water treatment plant for preparing treatment fluid for use in extracorporeal blood treatment, said plant including an ultraviolet lamp of such intensity and wavelength as to provide disintegration of chloramines.
21. A plant as in claim 20 in which said lamp emits energy that includes a substantial component at approximately 245 nm wavelength and has an output power in the range 750mJ/cm2 up to 1500 mJ/cm2.
22. A fluid container device, comprising:
- a sealed sterilized container with a conductivity sensor in communication with an interior of said container;
- at least a first sealed connector at the end of a first line adapted for adding fluid to said container,
- said first sealed connector having a second connector inline therewith;
- said second connector being configured to close said first line when said second connector is disconnected from said first connector such that said first connector may be left attached to a mating external connector when said sealed sterilized container is removed from said first connector and said closed first line provides a sterile seal to said mating external connector.
23. A treatment plant for preparing purified water for medical use, comprising:
- a controller having a data carrier reader;
- a station on said controller adapted to receive containers for receiving purified water, each carrying software,
- said controller being configured to download software instructions via said data carrier reader for performing a water treatment operation when a container is received by it;
- said controller being further configured to execute said software instructions.
24. A treatment plant for preparing purified water for medical use, comprising:
- a controller having a data carrier reader;
- a station on said controller adapted to receive containers for receiving purified water, each having a respective data carrier with a unique identifier,
- said controller being configured to read a unique identifier and compare a read unique identifier from a respective data carrier, when a container is received by said station, to at least one other identifier and to prevent a water preparation operation or proceed with a water preparation operation responsively to a result of said comparison.
25. A plant as in claim 24, wherein said controller is further configured with an output and to output instructions to replace a container when a result of said comparison indicates that a container was previously used.
26. A blood treatment machine, comprising:
- a controller having a data carrier reader;
- a station on said controller adapted to receive filled containers of purified water, each having a respective data carrier with an indicator of a date that a corresponding container was filled with purified water,
- said controller being configured to read said indicator and to prevent blood treatment operation or proceed therewith responsively to said indicator.
27. A treatment plant for preparing purified water for medical use, comprising:
- a controller having a data carrier reader;
- a station on said controller adapted to receive filter modules for purifying water, each having a respective data carrier with a unique identifier,
- said controller being configured to read a unique identifier and compare a read unique identifier from a respective data carrier, when a module is received by said station, to at least one other identifier and to prevent a water preparation operation or proceed with a water preparation operation responsively to a result of said comparison.
28. A medical material preparation device, comprising:
- a controller having a data carrier reader;
- a station on said controller adapted to receive consumable elements required for preparing a medical material used for medical treatment, each element having a respective data carrier with a unique identifier,
- said controller being configured to read a unique identifier and compare a read unique identifier from a respective data carrier, when a consumable element is received by said station, to at least one other identifier and to prevent a preparation operation or proceed with a preparation operation responsively to a result of said comparison.
29. A replaceable multi-use filter module for preparing purified water, comprising:
- one or more cartridges with a strong acid cation (SAC) filter bed and a strong base anion (SBA) filter bed in at least two segregated layers and configured such as to substantially remove colloidal aluminum from water treated with said module.
30. A module as in claim 29, wherein said SAC and SBA beds are in separate cartridges.
Type: Application
Filed: Jan 7, 2005
Publication Date: Sep 4, 2008
Inventor: Jeffrey Burbank (Boxford, MA)
Application Number: 10/585,675
International Classification: B01D 35/157 (20060101); B01D 39/00 (20060101); B01D 24/00 (20060101); B01D 15/00 (20060101); B01D 15/04 (20060101); B01J 39/00 (20060101);