US3809241A - Self-container kidney dialysis apparatus - Google Patents

Abstract

An improved kidney dialyzer. An improvement to kidney dialysis machines which provides for the portability of the apparatus. The improvement comprises a portable dialysate delivery system comprising a pump assembly flow section. The pump assembly flow section is made up of the artificial kidney, a heat reclaiming element and a recirculation pump for the dialysate passing therethrough. The pump assembly flow section is adapted to be connected to either a single pass dialysate proportioning system or a bath dialyzer reservoir cell. The pump used for recirculation of the dialysate solution is the source for the heat reclamation element, the recirculation pump being coupled to a clutch assembly used to control operation of a blood pump in the blood circulation system. The present invention is adapted to operate on any input voltage pursuant to a self-contained power transmission source.

Description

United States Paten [191 Alvine [451 May 7,1974

[75] Inventor: Charles E. Alvine, Palos Verdes Peninsula, Calif.

[73] Assignee: Electro Systems Engineeering, Inc.,

Palos Verdes, Peninsula, Calif.

[22] Filed: Feb. 23, 1973 [21] Appl. No.: 335,006

[52] US. Cl 210/87, 210/94, 210/186, 210/321 [51] Int. Cl 801d 13/00 [58] Field of Search 210/321, 322

[56] References Cited UNITED STATES PATENTS 3,441,136 4/1969 Serfass et al 210/321 X 3,489,647 1/1970 Kolobow 210/22 X 3,515,275 6/1970 Bowman 210/22 3,598,727 8/1971 Willock 210/22 3,703,959 11/1972 Raymond... 210/321 X 3,746,175 7/1973 Markley 210/321 3,754,649 8/1973 Palubniak et al. 210/321 OTHER PUBLICATIONS J. W. Eschbach, et al., Unattended Overnight Home 4 r, t is I-Iemodialysis, Article in Trans. Amer. Soc. Artif. Int. Organs, Vol. XII, 1966, pages 346-355.

Primary ExaminerRoy Lake Assistant Examiner-Paul A. Bell [5 7 ABSTRACT An improved kidney dialyzer. An improvement to kidney dialysis machines which provides for the portability of the apparatus. The improvement comprises a portable dialysate delivery system comprising a pump assembly flow section. The pump assembly flow section is made up of the artificial kidney, a heat reclaiming element and a recirculation pump for the dialysate passing therethrough. The pump assembly flow section is adapted to be connected to either a single pass dialysate proportioning system or a bath dialyzer reservoir cell. The pump used for recirculation of the dialysate solution is the source for the heat reclamation element, the recirculation pump being coupled to a clutch assembly used to control operation of a blood pump in the blood circulation system. The present invention is adapted to operate on any input voltage pursuant to a self-contained power transmission source.

16 Claims, 12 Drawing Figures PATENTEUIAY 1.1914

SHEET 3BF 5 FATENTED A H914 SHEET u [If 5 PATENTEDMAY 7 m4 SHEET 5- [IF 5 SELF-CONTAINER KIDNEY DIALYSIS APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is generally related to kidney dialysis machines and, more particularly, to those dialysis machines having portable dialysate proportioning and delivery systems.

2. Prior Art The increasing use of kidney dialysis equipment has placed great stress on the need to reduce the cost of such equipment as well as provide means whereby the equipment could be used in other than hospital surroundings. The portability of kidney dialysis equipment is a difficult problem which has heretofore not been effectively solved by the devices disclosed in the prior art. One of the primary problems encountered by the prior art devices is the development of a dialysate delivery system which can be constructed in an effective, portable manner. l

The process of dialysis is generally considered the process of separating compounds or materials by the difference in their rates of diffusion through a colloidal semipermeable membrane. The kidney is the human bodys major organ of the excretorory system. The main functions of the kidney are to eliminate waste products, toxic materials and basic and nonvolatile acid radicals; the maintenance of a constant volume of circulating blood and the regulation of the fluid content of the body as a whole; the regulation of osmotic pressure relationships of blood and tissues; and the maintenance of the optimum concentration of certain individual constituents of the plasma. Portions of the kidney act as a filtration mechanism reabsorbing almost completely substances like sugar, chloride, sodium and bicarbonate, which are necessary to the body economy, and excreting waste substances like urea, creatinine, ammonium, phosphates, sulfates and uric acid.

As blood passes through the kidney, it is filtered by hundreds of thousands of microscopic units called nephrons. When the kidneys are in a state which precludes them from properly filtering unwanted sub-- stances from the blood, dialysis is required. The filtering process within each nephron is not an organic process, but is essentially a mechanical process, thereby making it possible to utilize an artificial kidney.

The complete process of dialysisyin artificial kidneys is beyond the scope of the present application, but it is believed that a brief description is necessary to fully understand the impact of the present invention. The central feature of all dialysis equipment is the membrane through which the waste products migrate from the patients blood to the dialyzing fluid. The diameter of the membrane pores are extremely small, the membrane passing water and small-molecule waste products. The large-molecule-blood proteins do not migrate through the membrane. Although the blood contains many small-molecule substances which are not waste products, e.g., glucose and salts of sodium, a proper balance is maintained by making the concentration of .the substances in the dialyzing fluid the same as is present in the patients blood.

Dialysis equipment shall generally be considered to be comprised of two subsystems, one constituting the blood circuit, the second constituting the dialysate delivery system. The interface of these two system is at an artificial kidney which iw well-known in the piror art, the present invention being directed to an improved dialysate delivery. system possessing the ability to function as both a bath dialyzer or a single-pass, proportioning dialyzer.

One of the devices disclosed by the prior art utilizes a separate source of water and concentrate. The proportion of dialysate concentrate and water depends upon the particular dialysate being used, proportions being typically in the range. of -35 parts of water to one part of dialysate concentrate. In the prior art system, the water is first heated to a temperature of approximately 37 C after which it passes through an air removal system. Where the proportioning and delivery system is to service a number of dialysis stations, the amount of water to be used must be regulated. In order to mix the water and concentrate, the concentrate and water are brought together at a mixing point which is generally located on the top of a bubble chamber. After mixing the concentrate and water, the mixture must 7 pass through a temperature controlled point to insure that the dialysate temperature does not exceed 42 C. In addition, the' dialysate must pass an electrical conductivity probe to assure that a required amount of electrical current will be conducted through the solution. The electrical conductivity of the solution is a function of the dialysate concentrate to water proportions. As can be seen, this device requires a substantial amount of hardware to proportion and deliver the mixed and heated dialysate solution. Since fixed sources of water and concentrate are required, and since this is typically the type of system which is used for multiple patient delivery, it is not adaptable for portability and therefore cannot meet some of the objectives of the present invention.

Other devices disclosed by the priorv art utilize diaphragm pumps with adjustable displacements or piston pumps with different size pistons to proportion the mix of concentrate and water. Where a diaphragm pump is used, the rupture of the diaphragm or the seal will destroy the effectiveness of the proportioning and delivery system since the mixture will be at the least defective, and possibly dangerous if the conductivity measuring apparatus is out of calibration. In addition, where mechanical pumps are used'in general, they can gradually drift away from their nominal mix ratio. In the event a poorly trained operator is operating the equipment, he may actually attribute the drift to the conductivity monitoring apparatus and may keep resetting this apparatus without independently checking the system. Even where differential pumps are used, the prior art devices are still subject to the same type of problems which are sought to be overcome'by the present invention.

The present invention provides improved kidney dialyzer apparatus by utilizing a dialysate pump assembly which is portable and which can be alternately used with a single-pass dialysate proportioning and delivery system as well as a self-contained reservoir cell. To provide proper heating of the dialysate solution, a recirculation pump is utilized in a manner which permits the heat dissipated from the pump driving apparatus to provide energy for heating the solution. In addition, the mechanical drive of the recirculation pump is utilized to control other pumps within the blood circuit of the total apparatus to insure safety of operation. To complete the portability of the present system, the power source means utilized to drive the present system can adapt any commercial power source level to the requirements of the electrical components used within the present invention apparatus.

SUMMARY OF THE INVENTION The present invention comprises improved kidney dialysis apparatus and, in particular, an improved delivery system used therein. A self-contained bath dialyzer reservoir cell is provided to supply a sourceof dialysate for the dialysis process. The reservoir cell constitutes a non-rigid container within which is an internal container for holding the dialysate concentrate. The'reservoir cell is adapted to be filled with a fixed volume of water with which to make the dialysate solution. The dialysate solution is coupled to a recirculation pumping means, a portion thereof being adapted to be a source of heat transfer to the dialysate solution to compensate for any heat loss which may occur as a result of environmental conditions. The heated dialysate solution is then coupled to the artificial kidney apparatus and again returned to the reservoir cell. To minimize heat loss from the reservoir cell, a multilayer insulating member is utilized at the surface thereof in a manner which will 'not detract from the total portability of the present invention.

The recirculation pump and blood pump utilized within the total system operate from a direct current motor which utilizes the output of the power source transmission element. Lastly, the mechanical coupling of the recirculation pump is used as a saftey factor to shut down any pumps in the blood circuit in the event any abnormality may be detected such as a blood leak, or conductivity malfunction.

It is therefore an object of the present invention to provide an improved kidney dialysis apparatus.

It is another object of the present invention to provide kidney dialysis apparatus which is portable. It is still another object of the present invention to provide an improved kidney dialysis device utilizing a self-contained recirculating source of dialysate solution or a single-pass dialysate proportioning system.

It is yet another object of the present invention to provide an improved kidney dialysate apparatus which is economical to fabricate.

The novel features'which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objectives and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawing in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawing is for the purpose of illustration and description only and is not intended as a definition of the limits of the invention.

BRIEF DESCRIPTION OF THE DRAWING FIG. 4 is a schematic, partial cross-sectional view of an embodiment of a combined recirculation pump and heat reclaiming unit for use in the form of the present invention shown in FIG. 2.

FIG. 5 is a schematic, partial cross-sectional view of a form of a kidney coil holder for use with the form of the present invention shown in FIG. 2.

FIG. 6 is an enlarged, partial cross-sectional view of the blood leak detector and flow indicator used with the form of the present invention shown in FIG. 2.-

FIG. 7 is an enlarged, side elevation view of the dialysate reservoir element of FIG. 2.

FIG. 8 is a cross-sectional view of the insulating blanket of FIG. 7 taken through line 8-8 of FIG. 7.

FIG. 9 illustrates another form of a kidney dialysis machine in accordance with the present invention.

FIG. 10 is a partial, cross-sectional view of a pressure reducing and heating canister used with the form of th present invention shown in FIG. 9. t

FIG. 11 is a dialysate metering valve for use with the form of the present invention shown in FIG. 9. I

FIG. 12 is a front perspective view of one-half of a portable dialysis assembly in accordance with the present invention.

DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT An understanding of the present invention improvement for kidney dialysis apparatus can be best gained by reference to FIG. 1 where schematic view of a kidney dialysis unit in accordance with the present invention is shown, the kidney dialysis unit being generally designated by thereference numeral 10.Kidney dialysis unit 10 is basically comprises of three subsystems, blood circuit system 1 1, dialysate pumping anddelivery system 12 and adialysate supply assembly 13. Blood circuit system 11, schematically shown in FIG. 1, can be a conventional unit used with standard kidney dialysis equipment, and except as specifically stated, is not a part of the present invention. Thearterial blood inlet 14 from the patient is coupled to a blood pump which in turn is coupled to the artificial kidney ordialyzer unit 15. The output fromdialyzel unit 15 is coupled to a conventional bubble trap via tubes, the output from the bubble trap being connected to venous outlet 16 which is coupled to the patient. The above description of blood circuit system 11 has beenfor the purpose of providing a general description of conventional portions of kidney dialysis equipment, there being no attempt to include such elements as saline priming supplies or other chemical input and output sources for controlling blood pressure, prevent clotting or other like functions. Other than the mechanical control of the blood pump 36 (FIG. 3) andkidney unit 15 as will be described 'hereinbelow, the remaining elements of blood circuit system 11 are considered as conventional and are not considered as part of the present invention.

Dialysate pumping anddelivery system 12 is constructed to provide portability of the total sytem. In addition, dialysate pumping anddelivery system 12 will cooperatively engage adialysate supply assembly 13 constructd as a single pass proportioning system or for use of a concentrate reservoir system as will be described hereinbelow. Dialysate pumping and deliversystem 12 receives the dialysate supply via lines 17 fromdialysate supply assembly 13. The inlet of the dialysate is to recirculationpump 18 to provide a motive force for the dialysate solution. To maintain the dialysate solution at an appropriate temperature,heat reclaiming unit 19 provides for sufficient transfer of heat to the dialysate solution to maintain the dialysate solution at an appropriate temperature of approximately 37 C.

As can be seen from FIG. 1, blood circuit 11 and dialysate pumping anddelivery system 12 overlap atartificial kidney 15. As will be explained hereinbelow,artificial kidney 15 provides the interface for the dialysate solution and the patients blood supply to carry out the dialysis process. The dialysate solution passes fromheat reclaiming unit 19 throughartificial kidney 15 to blood leak detector and flow indicator 20. The details of the designated elements of FIG. 1 as well as the preferred interface therebetween will be explained in detail hereinbelow.

An understanding of a form of the present invention utilizing a dialysate reservoir can be best gained by reference to FIG. 2. Improvements in the efficiency and operation of conventional kidney dialysis equipment is.

substantially brought about by the coupling of dialysate pumping anddelivery system 12 and a bath dialyzer reservoir cell as shown in FIG. 2. Bathdialyzer reservoir cell 25 is a nonrigid structure typically fabricated of plastic and having the general geometrical shape of a bag or other like container. Internal to the outer wall structure of bathdialyzer reservoir cell 25 is a smaller container for holding the dialysate concentrate solution, the container for the concentrate solution to be discussed hereinbelow. The dimensions of dialysate concentrate and bathdialyzer reservoir cell 25 are such that when filled with the bath solution, the volume is approximately 120 liters, the salt concentration being appropriate to the individual requirements. Dialysate concentrate andreservoir cell 25 should have sufficient excess volume to provide for accepting approximately 1 gallon of excess fluid. The excess fluid will typically be withdrawn from the patients blood supply during the dialysis process and must be stored in bathdialyzer reservoir cell 25.

Output tube 26 is connected from bathdialyzer reservoir cell 25 to the input ofrecirculation pump 27,tube extension 28 being thermally coupled to heat reclaimingunit 19 ofpower source 29 being used to driverecirculation pump 27.Power source 29 is typically a direct current motor having field windings which dissipate a substantial amount of heat. The mechanical coupling between the directcurrent motor 29 and recirculation pump 27 will be discussed in detail below. By thermallycoupling output tube 28 and the field windings ofmotor 29driving recirculation pump 27, the heat dissipated from the field windings frommotor 29 can be used by heatconduction or heat convection to raise the temperature of the dialysate solution to the proper temperature. A proper temperature for a dialysate solution is approximately 37 C and is typically monitored by a suitable temperature gauge which can be disposed at the input tokidney coil holder 15. Since the heat being dissipated from the field windings ofmotor 29driving recirculation pump 27 is used to maintain the dialysate solution at an appropriate temperature, a by-pass valve is typically coupled across the field windings. The manner of constructionheat reclaiming unit 19 through the use of the field windings ofmotor 29 will be explained in greater detail hereinbelow.

As mentioned previously, the dialysis process is carried out in an artificial kidney disposed withinkidney coil holder 15. Pursuant to the dialysis process, smallmolecule waste products are forced through the mem brane of the artificial kidney into the dialysis solution. The full details of the operation of an artificial kidney is beyond the scope of the present invention, the dialysis process itself being well known to persons having skill in the art.

The output ofartificial kidney 15 within dialysate pumping anddelivery system 12 is viatube 30. The dialysate solution passes throughblood leak detector 31 and flowindicator 32, the dialysate solution returning to bathdialyzer reservoir cell 25 viatube 33. As will be explained in detail hereinbelow, one of the elements of the present invention utilized to maintain the appropriate -temperature of the dialysate solution while in the reservoir cell is insulatingblanket 24. V

The remaining portion ofkidney dialysis unit 10 as shown in'FIG. 2 is the completion of blood circuit system 11. The inlet of the blood supply from the patient is via inlet tube 35, the blood supply passing throughblood pump 36. Blood pump 35 maintains a positive pressure differential of approximately 50 millimeters of mercury over that in dialysate pumping anddelivery system 12. The positive pressure differential insures maintenance of the sterility of the blood supply in the event that a blood lead occurs in the membrane of artificial'kidney 15. The output ofblood pump 36 entersartificial kidney 15 viatube 37. The outlet of the blood circuit system 11 fromartificial kidney 15 is attube 38,tube 38 passing the blood throughconventional bubble trap 39. The output ofbubble trap 39 is connected tovenous outlet 40 which is coupled to the patient.

The mechanical coupling betweenrecirculation pump 27,heat reclaiming unit 19 andblood pump 36 can be best seen by reference to FIG. 3. The elements of the present invention shown in FIG. 3 comprise pertinent portions of the dialysate pumping anddelivery system 12 shown in FIG. 2. The primary objective of the coupledmembers 27, 29, 36 and 47 shown in FIG. 3 is to provide motive power for circulating the dialysate solution and blood through artificial kidney 15 (FIG. 2).Primary power source 29 supplies the motive power forrecirculation pump 27 andblood pump 36 and is typically a'conventional fractional horsepower, direct-current motor.DC motor 29 is a conventional -unit being well known to persons having skill in the art.

Upon supplying DC power tomotor 29,shaft 45 ofmotor 29 will rotate to supply the primary rotational power torecirculation pump 27 andblood pump 36.Shaft 45 is coupled byconventional shaft coupling 46 through aspeed reducing gear 47 to rotatingshafts 48 and 49.Shaft 48 is coupled to recirculation pump 27 withshaft 49 being coupled toblood pump 36.

Since the pressure of blood circuit 11 is to be greater than the pressure of the dialysate solution passing through dialysate pumping anddelivery system 12, the rotational power supplied atshafts 48 and 49 can be adjusted accordingly. The output pressure and flow rate ofrecirculation pump 27 and blood-pump 36 are approximately proportional to the voltage applied toDC motor 29. The pressure of dialysate solution at the outlet ofrecirculation pump 27 should be approximately 250 millimeters of mercury at a flow rate of approximately 1.5 gallons per minute. As stated previously, the blood pressure of the blood supply through blood circuit 11 must be approximately 50 millimeters of mercury higher than the dialysate solution pressure and therefore the output ofblood pump 36 can be properly adjusted by the gear ratio ofspeed reducing gear 47 and therefore the rotational output atshaft 49.

The speed reduction ratio is also the torque multiplication ratio, therefore, the torque available at the input toblood pump 36 should exceed any loads to be driven byblood pump 36.Shaft 49 is coupled to drivingelement 50 of clutch 51. Drivenelement 52 of clutch 51 is in axial alignment with and engages drivingelement 50 to transfer the rotational power ofshaft 49. The engagingmedium 53 on driving and drivenelements 50 and 52 of clutch 51 can be conventional material. A form of the present invention utilizes a plastic fiber material such as stiff bristles to implement engagingmedium 53. When engaged, bristles '53 on driving and drivenelements 50 and 52 will mesh together providing the transfer of torque from drivingelement 50 to drivenelement 52. Although the scope of the present invention is broad enough to use conventional frictional couplings typically used with clutch engaging elements, the fibrous bristle material is preferred since the torque transmitted will be independent of the force applied to maintain contact between theclutch members 50 and 52. In addition, the fibrous medium will allow for slight axial mis'registration betweenshaft 49 andshaft 53 of bloodpump 3 6.

The manner of implementingheat reclaiming unit 19 through the use ofDC motor 29 can be best seen in FIG. 3 and FIG. 4. Durectcurrent motor 29 is a conventional direct-current motor having a rotational output atshaft 45. As can be seen from the partial, crosssectional view shown in FIG. 4,heat reclaiming chamber 19 is coupled to the exterior 'wall 55 ofdirectcurrent motor 29adjacent field windings 56 thereof. The temperature offield windings 56 will increase during operation ofmotor 29, the heat being dissipated throughexterior wall 55 intoheat reclaiming chamber 19.Heat reclaiming chamber 19 hasinlet tube 28 andoutput tube 41 through which dialysate solution will enter and exitheat reclaiming chamber 19. The outer wall. ofheat reclaiming chamber 19 is typically a thin walled stainless steel enclosure concentric withexterior wall 55 ofmotor 29. Theinner wall 57 ofheat reclaiming chamber 19 comprises spaced, radially projectingfins 58 extending intersticial to the remainder ofwall 57.Inner wall 57 is curved to cooperatively engage the outer surface ofexterior wall 55 ofmotor 29. Thermal engagement betweenwalls 55 and 57 is improved by disposing a layer of a silicone thermal conductivity As shown in FIG. 2, the output of the dialysate solution fromheat reclaiming unit 19 is viatube 41 and is directed to the inlet ofkidney coil holder 15. Referring now to FIG. 5, an enlarged, partial cross-sectional view of a typical artificial kidney for use with the present invention is shown.Kidney coil holder 15 is a sealedcylinder having inlet 60 at the bottom thereof coupled totube 41 supplying dialysate solution fromheat reclaiming unit 19.Kidney coil 61 is disposed withinthe interior cavity ofkidney coil holder 15,kidney coil holder 61 havinginput line 62 andoutput line 63 for the input and output of the blood supply respectively.Blood inlet 62 is coupled totube 38 through the sealedcover 64 ofkidney coil holder 15. In a like manner,outlet 63 ofkidney coil 61 is coupled totube 37 throughtop enclosure 64. The operation ofkidney coil 61 is well known to persons having skill in the art. As described hereinabove, the filtration of waste matter from the human kidney is a mechanical process which can be duplicated bykidney coil 61. Dialysate solution entering through inlet 60' is disposedadjacent kidney coil 61, the dialyysis constitutes the separation of mediums through-a sate solution being separated by the artificial membrane formed bykidney coil 61. The dialysate solution exiting atoutlet 65 has been subjected to the dialysis process.

The construction ofkidney coil holder 15 insures proper operation of the dialysis process. The cylindrical interior ofkidney coil holder 15 is provided with O-ring 66 to insure that dialysate solution entering at inlet will not flow around the outer surface ofkidney coil 61. In addition, the blood lines connected toinlet 62 andoutlet 63 are fitted with elastomeric seals which are molded to the blood line. A second O-ring 67 is disposed intermediate the holding chamber and cover 64 ofkidney coil holder 15.Cover 64 is secured by conventional clamps 68. To insure proper registration ofkidney coil 61,resilient pads 69 are disposed intermediate the lower surface ofcover 64 and the top ofkidney coil 61. The pressure exerted onresilient pads 69 will insure a forced fit betweenkidney coil 61 and O-ring 66.

The output ofdialyzer unit 15 to the dialysate pumping anddelivery system 12 is viatube' 30 which is coupled to shunttube 42 which directs the dialysate solution constructedblood leak detector 31 and flowindicator 32. As mentioned previously, the process of dialcolloidal semipermeable membrane. In this case, the process of dialysis takes place atdialyzer unit 15. Under suitable operating conditions, no portion of blood passing through blood circuit system 11 should compound intermediate walls '55 and 57. The silicone be detectable in the flow of dialysate solution fromdialyzer unit 15 to dialysate pumping anddelivery system 12. As will be discussed in detail below, the detection of blood byblood leak detector 31 will signal a malfuction and shut down operation ofblood pump 36 to thereby safeguard the patient.

Referring now to FIG. 6, an enlarged, schematic view of the blood leak detector and flow indicator 20 (FIG. 1) can be best seen. As shown in FIG. 2, the dialysate solution being output fromdialyzer unit 15 viatube 30 entersshunt tube 42 which deflects a portion of dialysate solution throughtube 75. The remainder of the dialysatesolution entering shunt 42 passes throughtube 76 and exits atshunt 43 to entertube 33 and regain entry todialysate supply assembly 13. The portion of dialysatesolution entering tube 75 entersblood leak detector 31 and flowindicator 32.

Blood leak detector 31 is used to detect the presence of blood in the dialysate solution. As mentioned previously, the artificial kidney present in kidney coil holder is to provide for a dialysate process whereby only waste products are filtered through the membrane of the artificial kidney. In the event a leak occurs whereby blood is passed through the membrane,blood leak detector 31 is to immediately determine the presence of blood in the dialysate solution and shut downblood pump 36. Referring again to FIG. 6,tube 75 is coupled to an opticallyclear member 77 through which the dialysate solution can be optically observed.Member 77 is coupled totube 78 which is in turn coupled to inlets 79 offlow indicator 32. Outlet 80 offlow indicator 32 is coupled totube 81 which is in turn coupled to shunt 43.

A pair oflight sources 82 and 83 and aphotodetector 84 are'in a planar relationship with each other, the output light fromlight sources 82 and 83 impinging upon the interior cavity ofmember 77.Light source 82 is typically a source of light having a red wave length, the light emitted fromlight source 83 typically emitting light having a green wave length. The light emitted fromlight sources 82 and 83 pass through the dialysate solution incavity 77, and are detected atphotodetector 84. Under normal conditions, the dialysate solution is clear and uncolored. The energy of the red and green light sources and their respective responses at thephotodetector 84 are equal. The two light beams are approximately 180 out of time phase. The response of thephotodetector 84 will typically produce a directcurrent output from thephotodetector 84 which indicates normal operation. When blood-is detected in the dialysate solution, the response ofphotodetector 84 to the beams fromlight sources 82 and 83 will be unequal producing an alternating current signal. The output of an alternating current signal fromphotodetector 84 is used to shut down the operation ofblood pump 36.

This can typically be mechanically carried out by separating the bushing intermediate the axially opposed invention to' be transported in a simplified manner. Bathdialyzer reservoir cell 25 is adapted to be received and be held within one-half of carryingstructure 95.

Carryingstructure 95 is fabricated substantially in the form of a suitcase. The remaining half of carryingstructure 95 holds the elements of blood circuit 11 and dialysate pumping anddelivery system 12 and will be described in detail hereinbelow. The purpose for carryingstructure 95 is to preventreservoir cell 25 from moving about during a dialysis operation by providing rigid sidewalls for securing bathdialyzer reservoir cell 25. As stated, dialysate concentrate and bathdialyzer reservoir cell 25 is a nonrigid structure and is of sufiicient size to hold approximately 120 liters ofdialysate solution 96 therein.Dialysate solution 96 is comprised of water and dispersed dialysate concentrate. As is schematically depicted in FIG. 7, bathdialyzer reservoir cell 25 has contained internally therein a closed and breakabledialysate concentrate container 97 which holds the appropriate amount of dialysate concentrate to be mixed with water to produce the desired proportion ofdialysate solution 96. As an example, a typical dialysate solution is in the proportion of 34 parts water to one part dialysate concentrate. Bathdialyzer reservoir cell 25 has a pair of input andoutput tubes 33 and 26 respectively which have been described heretofore in connection with FIG. 2.Diluted dialysate solution 96 is recirculated through the system, the diluteddialysate solution 96 exiting atoutput tube 26 and being recirculated back throughinput tube 33. Water and dialysate container 97'are entered into or purged from the interior cavity of bathdialyzer reservoir cell 25 at opening 98 inreservoir 25.

As mentioned previously, when using a recirculating reservoir ofdialysate solution 96 as shown in FIG. 7, care must be taken to insure that the solution is maintained at a proper temperature. When conducting kidney dialysis operations, the solution should be maintained at approximately 37 C. Since this is the normal temperature for the human body, it is possible that enshaft 53 ofbloodpump 36 and the driven friction element 52'of clutch 51. Theblood detector 31 described hereinabove is only typical of conventional blood detection apparatus which could be utilized by the present invention.

Flow indicator 32 being typically fabricated of an optically transparent material provides visual indication that the flow of dialysate solution through dialysate the dialysate solution.

Referring to FIG. 7, a more detailed view of bathdialyzer reservoir cell 25 can be seen. Bathdialyzer reservoir cell 25 is a nonrigid structure which is typically fabricated from a'flexible plastic material such as polyethylene or polyvinyl chloride having a typical thickness of 2 mils (0.002 inch). The flexibility ofreservoir cell 25 is required to allow the elements of the present ergy will be lost or otherwise radiated to the atmosphere thereby causing thedialysate solution 96 to dropin temperature. As previously discussed, the heat generated by thefield windings 56 of motor29 employed topower recirculation pump 27 is used to maintain the appropriate temperature, but other steps must be taken to insure that unnecessary temperature perturbations do not occur. As can be seen in the schematic representations of FIG. 2 and FIG. 7, aninsulation blanket 24 is disposed upon the upper surface of bathdialyzer reservoir cell 25. The illustration of ofinsulation blanket 24 as shown in FIG. 2 and FIG. 7 is schematic in nature, a detailed cross-sectional view' ofinsulation blanket 24 being shown in FIG. 8.Insulation blanket 24 is used to retain the heat and maintaindialysate solution 96 at a substantially constant temperature.Insulation blanket 24 is comprised of a central stratified core comprised of at least six layers,100a 100f, of aluminized Mylar film having a thickness of approximately 0.00025 inch. The outer layers ofinsulation blanket 24 are comprised of layers 101a and 10112 fabricated from aluminized Mylar film having a thickness of approximately 0.001 inch. The combination ofinsulation blanket 24 and the heat transfer process utilizing the heat dissipated fromfield windings 56 ofmotor 29driving recirculation pump 27blood pump 36 will allow one to maintain the temperature ofdialysate solution 96 at an appropriate temperature.

Referring now to FIG. 9, a schematic diagram of another form of a kidney dialysis unit utilizing elements of the present invention is shown. For the purpose of clarity, elements having like functions to that shown in FIG. 2 will use the same reference numerals shown in FIG. 2. As stated previously, one of the objectives of the present invention is to provide a portable dialysate pumping and delivery system which can operate with either the bath dialyzer reservoir cell 25 (FIGS. 2 and 7) or a single pass proportioning system. FIG. 9 illus trates a form of the present invention utilizing a single pass proportioning system. The single pass, proportioning dialyzer assembly provides a continuous production of fresh, diluted dialysate solution. The fresh dialysate solution is transported to dialysate pumping anddelivery system 12 where it is pumped through the artificial kidney held by kidney holding coil 15 (FIGS. 2 and 5). After passing through the artificial kidney, the dialysate solution flows through blood leak detector and flow indicator (FIG. 1), after which it is disposed of. Referring now to FIG. 9, water is admitted at pressure reducing valve 110. After being reduced to an appropriate water pressure, the water enters heating canister 111. The water output from heating canister 111 is at a temperature of approximately 37 C, the appropriate temperature for a dialysis solution. Asource 112 of concentrated dialysate solution also passes through heating canisterll l and is heated to a temperature of 37 C. The operation of heating canister 111 will be explained in detail hereinbelow. Water and concentrated dialysate solution are input to proportioningvalve 113. The proportioning of the concentrated dialysate solution and water is substantially accomplished by proportioning the cross-sectional area oftubes 114 and 115 enteringproportioning valve 113. The manner of accurately proportioning the water and concentrated dialysate solution will be explained in detail hereinbelow. Diluted dialysate solution is output from proportioningvalve 113 attube 114,tube 114 being coupled to aconventional temperature cell 115.Temperature cell 115 performs a conventional temperature measurement and outputs a signal toamplifier 116 which triggersalarm circuit 117.Alarm circuit 117 utilizes conventional circuits to detect that the temperature is not within appropriate limits and causes a shut down ofblood pump 36.

The diluted dialysate solution exits temperature cell 1 15 viatube 118 and entersconductivity cell 119.Conductivity cell 119 is a conventional device for measuring the electrical conductivity of a solution. The proper proportioning of water and the undiluted dialysate solution produces a predetermined electrical conductivity which is detected atconductivity cell 119. An output signal from conductivity cell 1 19 is amplified atamplifier 120 and input to alarmcircuit 121. The detection atalarm circuit 121 of an improper electrical conductivity will produce a response to shut downblood pump 36. The output of diluted dialysate solution from conductivity cell 1 19 is viatube 122 to dialysate pumping anddelivery system 12. The temperature and conductivity of the dialysate solution can be visually observed through the use ofconventional meters 123 and 124 respectively.

The details of heating canister 111 shown in FIG. 9

can be best seen by reference to FIG. 10. Heating can- 12 ister 111 comprises aninner chamber 125 for holding the water input atinlet 126. Thewater outlet 127 fromchamber 125 is coupled totube 115 as shown in FIG. 9. In the embodiment of heating canister 11 1 shown in FIG. '10,pressure reducing valve 128 is incorporated therein. Thepressure reducing valve 128 utilizes a needel-valve operated by afloat 129. The undiluted dialysate solution enters atinlet 130 and passes through a thin-walledmetallic coil 131, the dialysate solution exiting atoutlet 132 which is in turn coupled totube 114. Heating of canister 111 utilizes aconventional heating blanket 133 which is disposed about the periphery ofchamber 125. To prevent unwanted dissipation of heat,

a layer offiberglass insulation 134 fully encloses the top, bottom. and periphery ofchamber 125 leavingheater blanket 133 intermediate the peripheral wall ofchamber 125 andinsulation 134.Heating blanket 133 is connected byconventional wiring 135 to an electrical source. The water and undiluted dialysate solution entering canister 111 is heated to approximately 37 C preparatory to enteringproportioning valve 113.

As mentioned hereinabove, approximately proportioning of the undiluted dialysate solution and water can be made by controlling the cross-sectional area of theinput tubes 114 and 115 as well as the pressure sources of the two components. Fine control is performed by the use of a dialysate metering valve shown in FIG. 11 generally designated by thereference numeral 113.Inlet tube 114 is coupled to asection 141 of silicone rubber tubing.Solenoid valve 142 imposes a-downwardly directed force onpinch roller 143 which imposes a corresponding force onelastomeric tube 141. The flow of undiluted dialysatesolution passing tube 141 is controlled by varying the current applied to solenoid 142 via leads 144.Leads 144 are coupled toalarm circuit 121 and therefore to the output signal fromamplifier 120. The signal input toamplifier 120 is fromconductivity cell 119 and is used to vary the flow of undiluted dialysate solution throughtube 141 in conformity with the selected dialysate solution proportion.

Referring now to FIG. 12, a front perspective view of the mating section of carryingstructure 95 can be best seen. As stated previously, the present invention is to be a portable unit and therefore the portion of carryingstructure 95 mates to form an enclosure with that shown in FIG. 7. The section of-carryingstructure 95 illustrates the positionedkidney coil holder 15 with thedialysate outlet tube 30 depending therefrom.Blood inlets 62 and 63 are not connected. The front panel of the section of carryingstructure 95 illustrates the simplicity of the present invention. Inlet comprises the input torecirculation pump 27 and is adapted to be connected totube 26.Outlet 151 is coupled to shunt 43 (FIGS. 2 and 6) and is adapted to be coupled totube 33. Flow indicator 32 (FIGS. 2 and 6) discloses the indiciation that dialysate solution is flowing through dialysate pumping anddelivery system 12. Since one of the prime objectives of the present invention 'is safety, it has been repeatedly said that any malfunction of the system will result in shutting downblood pump 36. In this manner,blood pump 36 is available at the top panel of carryingstructure 95. In a like manner, a manual blood pumpclutch disengaging button 152 and a manual bloodpump engagement button 153 are accessible in a like manner. As stated previously, although the clutch mechanics are not shown in FIG. 3 intermediate the bushing inshaft 53, the implementation of a conventional clutch for engaging and disengagingblood pump shaft 53 iswell known in the art. In a like manner, avariable speed control 154 is provided for controlling the speed of the pumps to maintain appropriate flow rates, apump speed indicator 155 being provided for visually monitoring the speed of the pump. A bloodleak alarm indicator 156 is connected toblood leak detector 31 and is turned on by the detection of an unbalanced condition byphotodetector 84.Power switch 157 andpower indicator 158 are conventional components used to turn power on and off and indicate the presence or absence of same.

The operation of the present invention utilizes bathdialyzer reservoir cell 25 is initiated by breaking the seal onconcentrate container 97 within bathdialyzer reservoir cell 25. Water which has been previously heated to approximately 37 C is placed inreservoir cell 25 untilreservoir cell 25 is filled to the appropriate volume.Recirculation pump 27 is turned on and flow is verified atflow indicator 32. In addition, the temperature ofdialysate solution 96 is measured at a conventional temperature gauge inserted at an appropriate place in dialysate pumping anddelivery system 12.Dialyzer unit 15 is pressurized to a suitable pressure, typically being approximately 300 mm Hg, i.e., approximately 50 mm Hg higher than pressure ofdialysate solution 96, after which flow is again verified. The next step is to turn onblood pump 36 by the engaging of the clutch thereto via manualengaging button 153.Dialysate solution 96 will flow throughdialyzer unit 15, throughblood leak detector 31,flow indicator 32 and return to bathdialyzer reservoir cell 25. The output ofdialysate solution 96 fromreservoir cell 25 flows initially throughrecirculation pump 27 and thenadjacent field windings 56 ofmotor 29 to reclaim the heat dissipated therefrom. The flow ofdialysate solution 96 then passing throughheat reclaiming unit 19 flows intodialyzer unit 15. Insulation blanket 99 will help to maintain the appropriate temperature ofdialysate solution 96 by preventing a heat transfer by radiation or convection to the atmosphere. Any heat loss will be regained by the heat reclaiming process utilizingfield windings 56.

The present invention provides a kidney dialysis unit which is fully portable, efficient in operation and substantially easier and more economically fabricated than those devices disclosed in the prior art. The present invention is constructed in a manner which will provide for transfer of the unit to where the patient is located rather than requiring movement of the patient as is now required thereby satisfying all of the objectives of the present invention.

1 claim:

'1. Kidney dialysis apparatus for the dialysis of blood comprising:

a. dialysate supply means for producing a source of diluted, dialysate solution;

b. artificial kidney means for placing said diluted dialysate solution in juxtaposition to the blood whereby a dislysis process is executed, said artificial kidney means aving a dialysis solution input terminal and a dialysis solution output terminal, said dialysis solution output terminal coupled to said dialysate supply means;

c. a recirculation pump having dialysate solution input and output terminals, said dialysate solution input terminal coupled to said dialysate supply means;

d. power means for powering said recirculation pump, said power means including a heat source, said power means coupled to said recirculation pump; and

e. heat reclaiming means thermally coupled to said heat source for transferring the heat dissipated by said heat source to said dialysate solution, said heat reclaiming means coupling the dialysate solution output terminal of said recirculation pump and the dialysate solution input terminal of said artificial kidney means.

2. Kidney dialysis apparatus as defined in claim 1 wherein said. dialysate supply means comprises a flexible member having an exterior surface and an inner chamber of predetermined volume having dialysate solution input and output means for providing an input and output path for diluted, dialysate solution disposed within said chamber.

3. Kidney dialysis apparatus as defined in claim 2 further including thermal insulating means for retarding the transfer of heat therethrough, said thermal insulating means being disposed upon and in intimate contact with a portion of the exterior surface of said member whereby the transfer of heat from the dialysis solution disposed within said chamber is retarded.

4.'Kidney dialysis apparatus as defined in claim 1 wherein said dialysate supply means comprises a singlepass dialysate proportioning system including first and second sources of water and concentrated dialysate solution respectively, heating means coupled to said first and second sources for heating said water and said concentrated dialysate solution to a predetermined temperature, proportioning means coupled to said heating means for combining said water and concentrated dialysate solution in a predetermined proportion, said proportioning means coupled to the dialysate solution input terminal of said recirculation pump.

5. Kidney dialysis apparatus as defined in claim 1 wherein said power means comprises a direct-current motor having field windings, said heat reclaiming means being thermally coupled to said field windings.

6. Kidney dialysis apparatus as defined in claim 1 further including a blood leak detector having dialysate solution input and output terminals and a dialysate solution flow indicator having dialysate input and output output terminals and means intermediate said input and output terminals for providing a pressure head and inducing the circulation of blood, said blood output terminals being coupled to said artificial kidney means.

8. Kidney dialysis apparatus as defined in claim 7 wherein said blood pump includes a rotary input shaft coupled to said means intermediate said blood output and input terminal, said shaft being coupled to said power means.

9. A portable kidneydialysis system for the dialysis of blood comprising:

a. dialysate supply means for producing a source of diluted, dialysate solution; b. artificial kidney means for placing said diluted, di-

alysate solution in juxtaposition to the blood whereby a dialysis process is executed, said artifi- I cial kidney means having dialysate solution input and output terminals and blood input and output terminals;

c. a direct-current rotary power source having a rotating output shaft and internal means for producing a source of dissipating heat;

d. a recirculation pump having dialysis input and output terminals' and a rotary input power shaft, said rotary input power shaft being coupled to the rotary power output shaft of said power source, said dialysis input terminal being coupled to the dialysate solution output terminal of said dialysate supply means; I

e. a heat reclaiming member disposed in juxtaposition to the internal means of said rotary power source, said heat reclaiming means having dialysate solution input and output terminals, said dialysate solution input terminal being coupled to the dialysate solution output'terminal of said recirculation pump, the dialysate solution output terminal being coupled to the dialysate solution input terminal of said artificial kidney means;

f. blood detection means for detecting the presence of blood in the diluted dialysate solution;

g. flow indicator means for indicating the flow of diluted dialysate solution; and

h. means coupling said blood detection means and said flow indicator means to the dialysate solution output terminal of said artificial kidney means.

10. A portable kidney dialysis system as defined in claim 9 wherein said dialysate supply means comprises a flexible member having anexterior surface and an inner chamber of predetermined volume and having input and output means defining an input and output path for diluted, dialysate solution disposed within said chamber.

11. A portable kidney dialysis system as defined inclaim 10 further including thermal insulating means for retarding the transfer of heat therethrough, said ther- 16 makinsulating means being disposed upon and in intimate contact with a portion of the exterior surface of said member whereby the transfer of heat from the diluted dialysate solution disposed within said chamber is retarded.

12. A portable kidney dialysis system as defined in claim 11 wherein said thermal insulating means comprises a plurality of adjacent layers each fabricated form an alumnized plastic film. I

13. A portable kidney dialysis system as defined in claim 9 whrein said dialysate supply means comprises a single pass dialysate proportioning system including first and second sources of water and concentrated dialysate solution respectively, heating means coupled to said first and second sources for heating said water and concentrated dialysate solution to a predetermined temperature, proportioning means coupled to said heating means for combining said water and said concentrated dialysate solution in a predetermined proportion, said proportioning means coupled to the dialysate solution input terminal of said recirculation pump.

. 14. A portable dialysis system as defined in claim 9 wherein said heat reclaiming member further includes a chamber having an inner wall adapted to engage the portion of said rotary power source adjacent said internal means, said inner wall having spaced heat dissipating fins depending into said whereby the heat from said internal means is transferred to said dialysate solution.

15. A portable kidney dialysis system as defined in claim 9 further including a blood recirculation pump having blood input and output terminals, means for maintaing a predetermined pressure head, and a rotary input shaft coupled to said means, said blood output of said rotary power source.

Claims (16)

1. Kidney dialysis apparatus for the dialysis of blood comprising: a. dialysate supply means for producing a source of diluted, dialysate solution; b. artificial kidney means for placing said diluted dialysate solution in juxtaposition to the blood whereby a dislysis process is executed, said artificial kidney means aving a dialysis solution input terminal and a dialysis solution output terminal, said dialysis solution output terminal coupled to said dialysate supply means; c. a recirculation pump having dialysate solution input and output terminals, said dialysate solution input terminal coupled to said dialysate supply means; d. power means for powering said recirculation pump, said power means including a heat source, said power means coupled to said recirculation pump; and e. heat reclaiming means thermally coupled to said heat source for transferring the heat dissipated by said heat source to said dialysate solution, said heat reclaiming means coupling the dialysate solution output terminal of said recirculation pump and the dialysate solution input terminal of said artificial kidney means.

2. Kidney dialysis apparatus as defined in claim 1 wherein said dialysate supply means comprises a flexible member having an exterior surface and an inner chamber of predetermined volume having dialysate solution input and output means for providing an input and output path for diluted, dialysate solution disposed within said chamber.

3. Kidney dialysis apparatus as defined in claim 2 further including thermal insulating means for retarding the transfer of heat therethrough, said thermal insulating means being disposed upon and in intimate contact with a portion of the exterior surface of said member whereby the transfer of heat from the dialysis solution disposed within said chamber is retarded.

4. Kidney dialysis apparatus as defined in claim 1 wherein said dialysate supply means comprises a single-pass dialysate proportioning system including first and second sources of water and concentrated dialysate solution respectively, heating means coupled to said first and second sources for heating said water and said concentrated dialysate solution to a predetermined temperature, proportioning means coupled to said heating means for combining said water and concentrated dialysate solution in a predetermined proportion, said proportioning means coupled to the dialysate solution input terminal of said recirculation pump.

5. Kidney dialysis apparatus as defined in claim 1 wherein said power means comprises a direct-current motor having field windings, said heat reclaiming means being thermally coupled to said field windings.

6. Kidney dialysis apparatus as defined in claim 1 further including a blood leak detector having dialysate solution input and output terminals and a dialysate solution flow indicator having dialysate input and output terminals, the dialysate solution output terminal of said blood leak detector being coupled to the dialysate input terminal of said flow indicator, the dialysate input terminal of said blood leak detector being coupled to the dialysate solution output terminal of said artificial kidney means, the dialysate output terminal of said flow indicator being coupled to said dialysate supply means.

7. Kidney dialysis apparatus as defined in claim 1 further including a blood pump having blood input and output terminals and means intermediate said input and output terminals for providing a pressure head and inducing the circulation of blood, said blood output terminals being coupled to said artificial kidney means.

8. Kidney dialysis apparatus as defined in claim 7 wherein said blood pump includes a rotary input shaft coupled to said means intermediate said blood output and input terminal, said shaft being coupled to said power means.

9. A portable kidney dialysis system for the dialysis of blood comprising: a. dialysate supply means for producing a source of diluted, dialysate solution; b. artificial kidney means for placing said diluted, dialysate solution in juxtaposition to the blood whereby a dialysis process is executed, said artificial kidney means having dialysate solution input and output terminals and blood input and output terminals; c. a direct-current rotary power source having a rotating output shaft and internal means for producing a source of dissipating heat; d. a recirculation pump having dialysis input and output terminals and a rotary input power shaft, said rotary input power shaft being coupled to the rotary power output shaft of said power source, said dialysis input terminal being coupled to the dialysate solution output terminal of said dialysate supply means; e. a heat reclaiming member disposed in juxtaposition to the internal means of said rotary power source, said heat reclaiming means having dialysate solution input and output terminals, said dialysate solution input terminal being coupled to the dialysate solution output terminal of said recirculation pump, the dialysate solution output terminal being coupled to the dialysate solution input terminal of said artificial kidney means; f. blood detection means for detecting the presence of blood in the diluted dialysate solution; g. flow indicator means for indicating the flow of diluted dialysate solution; and h. means coupling said blood detection means and said flow indicator means to the dialysate solution output terminal of said artificial kidney means.

10. A portable kidney dialysis system as defined in claim 9 wherein sAid dialysate supply means comprises a flexible member having an exterior surface and an inner chamber of predetermined volume and having input and output means defining an input and output path for diluted, dialysate solution disposed within said chamber.

11. A portable kidney dialysis system as defined in claim 10 further including thermal insulating means for retarding the transfer of heat therethrough, said thermal insulating means being disposed upon and in intimate contact with a portion of the exterior surface of said member whereby the transfer of heat from the diluted dialysate solution disposed within said chamber is retarded.

12. A portable kidney dialysis system as defined in claim 11 wherein said thermal insulating means comprises a plurality of adjacent layers each fabricated form an alumnized plastic film.

13. A portable kidney dialysis system as defined in claim 9 whrein said dialysate supply means comprises a single pass dialysate proportioning system including first and second sources of water and concentrated dialysate solution respectively, heating means coupled to said first and second sources for heating said water and concentrated dialysate solution to a predetermined temperature, proportioning means coupled to said heating means for combining said water and said concentrated dialysate solution in a predetermined proportion, said proportioning means coupled to the dialysate solution input terminal of said recirculation pump.

14. A portable dialysis system as defined in claim 9 wherein said heat reclaiming member further includes a chamber having an inner wall adapted to engage the portion of said rotary power source adjacent said internal means, said inner wall having spaced heat dissipating fins depending into said whereby the heat from said internal means is transferred to said dialysate solution.

15. A portable kidney dialysis system as defined in claim 9 further including a blood recirculation pump having blood input and output terminals, means for maintaing a predetermined pressure head, and a rotary input shaft coupled to said means, said blood output terminals being coupled to the blood input terminal of said artificial kidney means and said rotary input shaft being coupled to the rotary output shaft of said rotary power source.

16. A portable kidney dialysis system as defined in claim 15 further including means responsive to the detection of the presence of blood in the diluted dialysate solution for stopping said blood recirculation pump, said means being disposed intermediate the input shaft of said blood recirculation pump and the output shaft of said rotary power source.

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