Patent ID: 12208187

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

An integrated system that can determine if a durable medical device, such as a dialysis machine (e.g., a dialysis machine at a hospital, a home dialysis machine, etc.), has been appropriately disinfected. The system can detect and log that disinfection has occurred, determine what disinfectant was used, determine the dwell time that the disinfectant wetted the machine, determine when the disinfection occurred, determine what sections of the machine were disinfected, determine who disinfected the machine, etc. With this information the medical device can give a clear indication such as an alarm and require proper disinfection protocol be implemented. This information can be used to require the staff to follow the training that they have been given. The information can also be used if an audit of disinfection practices is conducted.

FIG.1shows a high level schematic dialysis system100(e.g., a hemodialysis system or a peritoneal dialysis system) in which dialysis solution is moved under the force of at least one pump105from a dialysate module120to a dialysis machine110that includes a dialyzer140. Once through the dialyzer140, in some instances the dialysate passes through a sorbent device130within the dialysate module120and the recycled dialysis solution exits the sorbent device130and is moved back to the dialysis machine110. In some instances, there is no sorbent device130and spent dialysate that is generated in the dialysate module120and has passed through the dialyzer140is directed to a waste container or drain160. A controller150controls the functions of the dialysate module120.

As the dialysis solution passes through the dialyzer140in the dialysis machine110, toxins are transferred from the patient's blood into the dialysis solution, forming spent dialysis solution. This process can be repeated until a desired amount of toxins have been removed from the patient's blood.

FIGS.2A-2Dshow various portions of the dialysis machine110that can include small, unobtrusive disinfection sensors210. These disinfection sensors210are placed in areas or locations212that require surface disinfections. Multiple disinfection sensors210are used as there are several critical locations212to be kept disinfected, and the system100monitors the disinfected status of all these locations212as indicated by the disinfection sensors210. Locations212that have the disinfection sensors210include frequently-touched surfaces as well as other surfaces. For example, these locations212can include a dialysate machine monitor such as a touch screen (FIG.2A), a dialysate machine faceplate (FIG.2B), and sides of the dialysate machine (FIGS.2C and2D). The locations212may be chosen as places that are especially important to remain clean (e.g., due to typical subsequent touching of the patient) or places that have the potential to become dirty (e.g., due to frequent touching).

FIGS.3A-3Cshow components of the disinfection sensors210. The components include attachable portions220of the sensors210that attach to the surface to be disinfected at each location212, and portions of the surface itself at the location212that are configured to engage with the attachable portions of the disinfection sensors210.

Referring toFIG.3A, each disinfection sensor210has an attachable portion220that includes a small circuit board230with connected conductive pins or electrodes240. The electrodes240act as the contact point for the disinfection sensors210to the disinfection liquid used to clean the locations212. Two electrodes240are shown, although there can be one, three, four or more such electrodes240.

The attachable portion220of the disinfection sensors210can include a wetness sensor component232, a conductivity sensor component234, or both a wetness and a conductivity sensor component (as is depicted inFIG.3A). The circuitry for the wetness sensor component232and the conductivity sensor component234are located on the circuit board230. When a dialysis machine110is disinfected by having its surfaces wetted by liquid at locations212with disinfection sensors210, the disinfection sensors210will detect that the dialysis machine110is wet and/or the conductivity of the fluid via the electrodes240that are in contact with wetness sensor component232and/or the conductivity sensor component234. The wetness sensor component232and/or the conductivity sensor component234on the circuit board230are connected to a computer, e.g., the controller150. In some implementations, the conductivity detected by the conductivity sensor component234can be used to determine a type of disinfectant being used, for example, hydrogen peroxide, isopropyl alcohol solution, sodium hypochlorite, quaternary ammonium etc. Each of these and other disinfectants are used in different concentrations, for example, 10% hydrogen peroxide or 15%.

One factor that can contribute to high conductivity is residual disinfect left on the surface and then rewetting it. For example if a surface is wiped with a 0.6% sodium hypochlorite solution and then left to sit the water will evaporate and leave behind residual solids. The next time the surface is wiped down with 0.6% sodium hypochlorite solution the residual solids left behind will go into solution and create a higher concentration of sodium hypochlorite solution. The measured conductivity will use thresholds that account for this accumulation. In some instances, controller150can include adaptive algorithms that learn and account for this accumulation.

FIG.3Bshows an example of how the surface of the dialysis machine110at each location212can be configured to mate with attachable portion220including the circuit board230with connected electrodes240shown inFIG.3A. Each location212includes through holes250and bosses252. Nearly any surface of the machine110(in particular, surfaces that are plastic) can be adapted to accept the attachable portions220FIG.3A.

The cross section ofFIG.3Cdepicts how the attachable portion220is mounted at any given location212. The holes250on the surface of the machine mate with the electrodes240of the attachable portion220, and the bosses252on the surface of the machine accept screws254. The screws254(e.g., self-tapping screws) attach the circuit board230to the machine surface at the location212such that the electrodes240protrude through the holes250and are visible (and in fluid contact with) the outer surface256of the machine at location212. The electrodes240can be flush with the outer surface256(e.g., flat). In some instances, the electrodes240can protrude past the outer surface256such that a portion of the sides of the electrodes240extends a distance beyond the outer surface256(e.g., less than 1 mm) is not in contact with the outer surface256. The result is that the sensor210is in contact with and visible from the outer surface256, as shown inFIG.4.

The disinfection sensors210can include a wetness sensor component232configured to detect wetness on the outer surface256of a given location212. The wetness sensor component232detects that fluid (e.g., a disinfecting agent) is present at the location212. The disinfection sensor210can register the time at which the liquid is detected, and the time at which liquid is no longer detected. These times allow calculation of the dwell time by the controller150that the surface is wetted, e.g., time in contact with a disinfection fluid.

In some instances, the controller150can include in memory a saved time period against which to compare the calculated dwell time. The saved time period can equal a time that is known, or is recommended, that a surface remain wetted by disinfection fluid for that surface to be considered clean or disinfected. The controller150is thus configured to detect that fluid on the surface was wet from an initial time point and remained wet and not dried enough for the disinfecting fluid to be inactive.

In some instances, channels can be positioned in the outer surface256so that disinfection fluid becomes trapped in the channels. Such an arrangement ensures that evaporation does not cause the disinfection fluid to not register as meeting the time threshold.

In some embodiments, the disinfection sensor210includes a conductivity sensor component234. When wetted with a disinfection fluid, the electrodes240register a change in conductivity that is read by the conductivity sensor component234. Certain measured conductivity values can be associated with the presence of a disinfection fluid on the outer surface256. The disinfection sensor210can register the time at which the change in conductivity and thereby the disinfection liquid is detected, and the time at which it is no longer detected. These times allow calculation of the dwell time by the controller150that the surface is in contact with the disinfection fluid.

In some instances, the controller150can include in memory a saved time period against which to compare the calculated dwell time. The saved time period can equal a time that is known, or is recommended, that a surface remain wetted by a disinfection fluid for that surface to be considered clean or disinfected.

In some embodiments, the controller150can correlate the conductivity value measured the disinfection sensor210with the conductivity of a known disinfection fluid. For example, the controller150can include a memory that stores a look-up table that contains the conductivity values of a range of commonly used disinfectants, (e.g., bleach). By comparing the measured conductivity value with the stored conductivity values, the controller150can thereby determine which disinfection fluid was used.

The concentration of the disinfection fluid changes as the applied fluid dries and evaporates from the outer surface256. The controller150can include information correlating a range of conductivity measurement to a known disinfection fluid. In some instances, the disinfection fluid used can be selected so that the needed dwell time is short, e.g., less than 3 minutes. In such an instance the conductivity measurements are not affected during the period of time the surface is wetted since not enough water will evaporate to change the concentration of the disinfection fluid.

In some instances, channels can be positioned in the outer surface256so that disinfection fluid becomes trapped in the channels. Such an arrangement ensures that evaporation does not cause the disinfection fluid to not register as meeting the time threshold.

There can be multiple locations212on the dialysis machine110. Some of the locations212will be horizontal whereas some will not and no not be able to make use of gravity to fill a surrounding channel and hold the fluid in place while the conductivity measurement is taken. In such instances, a single conductivity reading can be taken in a single horizontal location. The rest of the sensors at other locations212can simply be wetted and the system can assume that the same disinfectant and dwell time were employed as at the horizontal, representative location.

FIG.4shows how the disinfection sensor210looks from the outer surface256. In this example, only the end portions of the electrodes240are visible on the outer surface256.

FIGS.5and6show another configuration for mounting a disinfection sensor270as seen from the outer surface256and in cross-section, respectively. The disinfection sensor270is similar to the disinfection sensor210described above, and with like reference numbers referring to like parts. However, the disinfection sensor270includes an additional fluid channel260that is in the outer surface256of the machine110at the location212to be disinfected. The channel260is a blind hole and is located in fluid communication with the ends of the electrodes240. The channel260is configured such that disinfecting fluid applied to the surface256will pool or become trapped in the channel260. This configuration ensures that sufficient disinfecting fluid will be available to the electrodes240so that they can detect the presence of the disinfecting fluid (through wetness or conductivity change, or both). In some instances, the channel260can ensure that the disinfecting fluid present does not change its concentration over the dwell time stored in memory as necessary for successful disinfection of the outer surface256. Although the channel260is illustrated as a single linear channel, other configurations are possible. For example, channels can intersect each electrode240of a disinfecting sensor210individually, or have a different shape than illustrated (e.g., a circle).

The information collected by the disinfecting sensors210can be used to determine and alert a user that a dialysis machine110is disinfected. The controller150can determine whether the proper disinfectant was used, the proper dwell time was used, the machine was disinfected in all specified locations, the machine was disinfected at the correct intervals, and that trained personnel disinfected the machine. The information stored in the machine could also be used for audit purposes.

A user interface can inform a user whether or not the machine is clean as determined by the disinfection sensors210and the controller150. The indication of disinfection status for a particular location212can indicate “clean” or “not clean” for example. A particular location212can be indicated as “clean” if an appropriate disinfection fluid was detected for the appropriate dwell time, and within a given interval, such as hourly, time between treatments, end of the day. The machine's main display (as inFIG.2A) can include a disinfection status as part of the user information displayed. The disinfection status can be displayed in multiple ways, e.g., a traffic light (red, yellow, green), a “not clean” light, or message indicating not disinfected, among others.

In some embodiments, disinfection status can be localized to each location212. For example, a light such as an LED light can be integrated into each sensor210(e.g., on the circuit board230). If the controller150has determined that a particular disinfection location212is clean or dirty, the light can change status, for example, by toggling on or off, or by changing color. In some instances, when the sensor210detects the presence of disinfection liquid (by conductivity change and/or by wetness) the light at that sensor location can change to indicate the start of disinfection and the end of disinfection. For example, the light change may be turning on or off, or changing color.

In some embodiments, the memory within the controller150can include recommended machine-cleaning intervals. The machine can warn users that the machine, or parts of the machine, needs cleaning. The recommended cleaning intervals can be different for differing locations212. The machine can log when the disinfections occurred (between treatments, at the end of the day, at the beginning of the day, etc.). In some instances, the machine can log who conducted the disinfection, for example, requiring a user typing a pin code, a card reader, facial recognition, etc. The information can also be stored and supplied if an audit of disinfection practices is conducted.

The machine can give an indicator such as an alarm and require proper disinfection protocol be implemented, ensuring that staff follow training on cleanliness protocols. In some instances, the controller150can prevent use of the machine if it is determined to be not clean.

FIG.7shows a block diagram of an example computer system700. For example, the controller described above with respect toFIG.1could be an example of the system700described here. Thus, the system700may be part of the dialysis machine ofFIG.1, and may be configured to assist in managing disinfection information. For example, the system700may determine information related to disinfection and be used to view alarms, logs, etc. related to such disinfection.

The system700includes a processor710, a memory720, a storage device730, and an input/output device740. Each of the components710,720,730, and740can be interconnected, for example, using a system bus750. The processor710is capable of processing instructions for execution within the system700. The processor710can be a single-threaded processor, a multi-threaded processor, or a quantum computer. The processor710is capable of processing instructions stored in the memory720or on the storage device730. The processor710may execute operations such as causing the dialysis system to carry out functions related to a dialysis treatment and determining information related to disinfection.

The memory720stores information within the system700. In some implementations, the memory720is a computer-readable medium. The memory720can, for example, be a volatile memory unit or a non-volatile memory unit. In some implementations, the memory720stores information related to a treatment to be administered to a patient and information (e.g., logs) related to past and/or current disinfections.

The storage device730is capable of providing mass storage for the system700. In some implementations, the storage device730is a non-transitory computer-readable medium. The storage device730can include, for example, a hard disk device, an optical disk device, a solid-date drive, a flash drive, magnetic tape, or some other large capacity storage device. The storage device730may alternatively be a cloud storage device, e.g., a logical storage device including multiple physical storage devices distributed on a network and accessed using a network. In some implementations, the information stored on the memory720can also or instead be stored on the storage device730.

The input/output device740provides input/output operations for the system700. In some implementations, the input/output device740includes one or more of network interface devices (e.g., an Ethernet card), a serial communication device (e.g., an RS-232 port), and/or a wireless interface device (e.g., a short-range wireless communication device, an 802.11 card, a 3G wireless modem, or a 4G wireless modem). In some implementations, the input/output device740includes driver devices configured to receive input data and send output data to other input/output devices, e.g., a keyboard, a printer, and display devices (such as the touch screen106). In some implementations, mobile computing devices, mobile communication devices, and other devices are used.

In some implementations, the system700is a microcontroller. A microcontroller is a device that contains multiple elements of a computer system in a single electronics package. For example, the single electronics package could contain the processor710, the memory720, the storage device730, and input/output devices740.

Although an example processing system has been described inFIG.7, implementations of the subject matter and the functional operations described above can be implemented in other types of digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Implementations of the subject matter described in this specification can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a tangible program carrier, for example a computer-readable medium, for execution by, or to control the operation of, a processing system. The computer readable medium can be a machine readable storage device, a machine readable storage substrate, a memory device, a composition of matter effecting a machine readable propagated signal, or a combination of one or more of them.

The term “computer system” may encompass all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. A processing system can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them.

A computer program (also known as a program, software, software application, script, executable logic, or code) can be written in any form of programming language, including compiled or interpreted languages, or declarative or procedural languages, and it can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile or volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks or magnetic tapes; magneto optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet.

In some embodiments, the device can make use of touch screens. There are several touch screen technologies, one of them being capacitive. A capacitive touchscreen panel has an insulator, such as glass, coated with a transparent conductor, such as indium tin oxide (ITO). As the human body is also an electrical conductor, touching the surface of the screen results in a distortion of the screen's electrostatic field. The distortion in the electrical field caused by a person touching the surface of the screen is measurable as a change in capacitance. Different technologies may be used to determine the location of the touch. The location is then sent to the controller150for processing.

Different disinfecting fluids are also electrical conductors. The conductivity of the different disinfectant can have different levels of conductivity, causing the distortion of the screen's electrostatic field to change depending on the conductivity of the fluid that is placed on it. Furthermore, small channels that collect fluid (e.g., channel260) can be placed near the capacitive touch screen so that a known amount of fluid collects in them. The channels would have to be easily cleanable.

FIG.8is an example of an integrated capacitive touchscreen. A clear shelf is built into the door, with a pocket that the capacitive touchscreen can sit in. The circuit board and batteries can sit under it and be accessible by a small plastic door. The capacitive touchscreen and the plastic shelf have similar optical properties and can be bonded together with an optical clear adhesive that has similar optical properties as the touch screen and shelf. The capacitive keyboard can be integrated into the door that can sense capacitance of the keyboard/touch screen itself and tell if keyboard capacitive touch is wetted.

Two electrodes240are shown in the figures, although there can be one, three, four or more such electrodes240. Determining a conductivity measurement, using two, three, or four contacts depends on the cell constant. When determining a cell constant having a consistent amount of fluid to measure is factor, as is the spacing of the electrodes from each other. By having a small, accurate, cleanable channel molded into the plastic of the machine, a known amount of disinfectant can fill that channel, allowing for a repeatable cell constant and thus accurate conductivity measurements. Once a known conductivity is established, it can be compared to a table of disinfectants with known conductivities. With two electrodes, for example, the spacing between the center lines of the electrodes is known to a high degree of accuracy, as the volume of fluid captured in the channel. The size, material, surface finish, and other properties of the electrodes is known. Knowing these properties allows the cell constant to be determined. The channel can also be cleaned so that no residual fluid affects future measurements.

The repeatability of the fluid being measured influences the conductivity measurements when using a capacitor. The capacitor creates field lines, and if a channel is created next to the capacitor that is repeatable, the disruption of the field lines are repeatable as well, and thus measurable.

If specific conductivity is not important to the system's modality, then the system simply determines if the channel has been wetted, and for what period of time. In such an embodiment, the accuracy of the channel is less of a factor in determining the measurements.

A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.