Fluid pump with adaptive filter

Abstract

A method includes measuring a fluid pressure of a fluid in a fluid supply line of an infusion pump. The fluid pressure includes a motor pressure and a patient pressure. The method also includes determining the patient pressure. The determining includes removing, by an adaptive filter, to remove the motor pressure from the measured fluid pressure. The removing includes generating a predicted motor pressure based on a current of the motor, generating an error signal based on a comparison between the predicted motor pressure and the measured fluid pressure, and removing the motor pressure from the measured fluid pressure when an error value indicative of the error signal is less than an error threshold. The method also includes adjusting a setting of the infusion pump based on the patient pressure. Related methods and articles of manufacture, including apparatuses and computer program products, are also disclosed.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 986,095, filed March 6, 2020, entitled “Fluid Pump with Adaptive Filter,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The subject matter described in this article generally relates to fluid distribution, and more specifically, to pump systems with adaptive filters for infusion devices used to deliver fluid drugs. Background Technology

[0004] Fluid pumps (e.g., infusion pumps) treat patients by delivering medications or other fluids to them. The pump may be connected to a fluid delivery line, such as an intravenous line or other administration device. Fluid delivery can be adjusted based on the fluid pressure within the delivery line to help ensure proper patient treatment. During fluid delivery, patient movement or other sources can cause fluctuations in fluid pressure within the delivery line, which, if unmonitored, can lead to unintended boluses, under-delivery, and / or cessation of fluid delivery to the patient, resulting in various medical complications. Determining changes in fluid pressure attributable to patient movement or other sources and adjusting the pump to account for those changes can be difficult because the pump motor also contributes to fluid pressure. Sensors and detection methods used to measure fluid pressure (e.g., direct flow rate measurements) can often be unreliable, inaccurate, and require significant device resources (e.g., power, processing time, memory, network bandwidth, etc.), especially for low flow rates of fluid delivered to the patient. Summary of the Invention

[0005] Systems, methods, and articles comprising computer programs are provided for using adaptive filters on fluid pumps, such as infusion pumps, to separate the contributing factors of fluid pressure within a fluid delivery line connected to the fluid pump. The systems described herein more effectively adjust one or more fluid pump settings to improve feedforward control of the fluid pump and reduce unintended spurting, under-delivery, and / or interruption of fluid flow within the fluid delivery line due to changes in downstream pressure.

[0006] According to some aspects, a method includes measuring a fluid pressure of a fluid in a fluid supply line of an infusion pump. The fluid pressure can include a motor pressure and a patient pressure. The method can also include determining the patient pressure. The determining can include removing, by an adaptive filter, the motor pressure from the measured fluid pressure. The removing can also include generating a predicted motor pressure based on a current of the motor, generating an error signal based on a comparison between the predicted motor pressure and the measured fluid pressure, and removing the motor pressure from the measured fluid pressure when an error value indicative of the error signal is less than an error threshold. The method also includes adjusting a setting of the infusion pump based on the patient pressure.

[0007] In some aspects, the removing further includes generating a predicted motor pressure based on a current of the motor. The removing can also include generating an error signal based on a comparison between the predicted motor pressure and the measured fluid pressure. The removing can further include removing the motor pressure from the measured fluid pressure when an error value indicative of the error signal is less than an error threshold.

[0008] In some aspects, the current of the motor is stored in a shift register of the adaptive filter.

[0009] In some aspects, the adaptive filter is a digital adaptive filter.

[0010] In some aspects, the comparison between the predicted motor pressure and the measured fluid pressure is a difference between the predicted motor pressure and the measured fluid pressure.

[0011] In some aspects, the error value is one or more of a norm of the error signal and a minimum mean square of the error signal.

[0012] In some aspects, generating the error signal further includes applying tap filter coefficients to the error value.

[0013] In some aspects, the removing further includes determining whether the error value is less than an error threshold. In some aspects, the removing further includes determining that the error value is greater than or equal to a threshold. The removing can also include adjusting one or more filter coefficients of the filter. The one or more filter coefficients can be applied to the current of the motor. In some aspects, the removing can also include generating an updated predicted motor pressure based on the adjusted one or more filter coefficients and the current of the motor.

[0014] In some aspects, the removing further includes generating an updated error signal based on a comparison between the updated predicted motor pressure and the measured fluid pressure. The removing can also include determining that an updated error value indicative of the updated error signal is less than an error threshold.

[0015] Implementations of the current subject matter can include methods, as well as articles of manufacture, including tangible, machine-readable media, that operate in conjunction with one or more machine (e.g., a computer) to produce an operation that implements one or more of the described features. Similarly, computer systems are also described that can include one or more processors and one or more memories coupled to the one or more processors. The memories, which can include non-transitory computer-readable or machine-readable storage media, can include one or more programs, which instruct the one or more processors to perform one or more of the operations described herein. Computer-implemented methods consistent with one or more implementations of the current subject matter can be implemented by one or more data processors, e.g., a computer, which operates one or more processes consistent with one or more implementations of the current subject matter. Such a computer can be found in many computers, such as one or more computers that form a server, a client, a mobile device, a network appliance, a set-top box, a kiosk, a personal computer, a workstation, a mainframe computer, a television, a television set-top box, a personal digital assistant, a mobile device, a telephone, a web appliance, a network router, a network switch, a network bridge, or other computing device. Such a computer can be under the control of one or more operating systems and execute one or more computer programs.

[0016] Details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. While certain features of the currently disclosed subject matter are described for illustrative purposes with respect to a pump system having an adaptive filter, it can be readily appreciated that such features are not intended to be limiting. The claims attached to the end of this specification are meant to define the scope of the protected subject matter. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate some aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawings,

[0018] Figure 1 Depicts a system diagram showing a pump system in accordance with some example implementations;

[0019] Figure 2 Schematically depicts an example pump in accordance with some example implementations;

[0020] Figures 3A to 3C Depicts a graph showing example readings from a pump in accordance with some example implementations;

[0021] Figures 4A to 4B Schematically depicts an adaptive filter and predictor coupled with a pump in accordance with some example implementations;

[0022] Figure 5 A flow diagram for adjusting pump settings based on a patient pressure component of fluid pressure, in accordance with some example embodiments, is depicted;

[0023] Figure 6 A block diagram showing a computing system, in accordance with some example embodiments, is depicted;

[0024] Figure 7A A front view of a patient care system, in accordance with some example embodiments, is depicted;

[0025] Figure 7B An enlarged view of a portion of a patient care system, in accordance with some example embodiments, is depicted; and

[0026] Figure 7C A perspective view of a pump, in accordance with some example embodiments, is depicted.

[0027] In the actual figures, similar reference numerals indicate similar structures, features or elements. DETAILED DESCRIPTION

[0028] Fluid pumps (e.g., infusion pumps) treat patients by delivering medication or other fluids to the patients. Fluid pumps can be connected with fluid delivery tubing, such as intravenous tubing or other administration devices. Various parameters of fluid delivery by a fluid pump can be adjusted based on fluid pressure of fluid passing through the fluid delivery tubing to help ensure that an appropriate amount of fluid is delivered to the patient. During use of a fluid pump, patient movement or other sources can cause fluctuations in fluid pressure within the fluid delivery tubing, which, if not monitored, can result in unintended bolus delivery, under-delivery, and / or cessation of fluid to the patient, leading to various medical complications. It can be difficult to determine changes in fluid pressure attributable to patient movement or other sources and to adjust the pump to account for those changes, as the motor of the pump also contributes to fluid pressure. Sensors and detection methods for measuring fluid pressure (e.g., direct flow rate measurements) can often be unreliable, inaccurate, and require significant device resources (e.g., power, processing time, memory, network bandwidth, etc.), especially for low flow rates of fluid delivered to the patient.

[0029] The pump systems described herein can employ an adaptive filter to improve the accuracy of detecting fluid pressure changes attributable to patient movement or other sources (other than the pump motor), which facilitates reliably adjusting pump settings for improved feedforward control of the pump and to reduce unintended bolus, under-delivery, and / or cessation of fluid delivery to the patient. The adaptive filter can be a digital or analog filter with self-tuning properties. For example, the adaptive filter can be able to adjust (e.g., continuously and / or at various time intervals) one or more coefficients of the filter to adapt or otherwise improve the accuracy of an input signal, such as one or more motor current measurements. In some embodiments, the adaptive filter is adjusted until an error (e.g., a difference between an output of the filter and a desired signal) is minimized and the filter converges to an optimal state. For example, when the adaptive filter adapts its coefficients, the error converges to a minimum value. When the error converges to a minimum value, the adaptive filter has been adapted and the coefficients of the filter have converged to an output (e.g., motor pressure, patient pressure, and / or the like). In some embodiments, the adaptive filter is a filter system that includes one or more (e.g., one, two, three, four, or more) filters, such as a linear filter, a variable filter, a least mean square filter, a recursive least square filter, and / or the like.

[0030] Incorporating an adaptive filter in the context of the pump systems described herein can be particularly useful when using a pump to deliver fluid to a patient, as the pump (e.g., a motor of the pump) can affect fluid pressure signal readings corresponding to fluid within a fluid delivery tube by generating a significant amount of noise in the fluid pressure signal. Pump systems incorporating the adaptive filters described herein can help reduce or eliminate the noise generated by the pump from the fluid pressure signal to provide a fluid pressure signal with improved accuracy, reliability, and efficiency. As a result, the pump systems can desirably provide improved feedforward control of the pump and reduce unintended bolus, under-delivery, and / or cessation of fluid delivery to the patient.

[0031] Accordingly, in some examples, an adaptive filter used in a pump system can help separate contributing factors of a fluid pressure signal, such as a pump motor contribution, a patient contribution, and / or the like. For example, an adaptive filter can be determined by comparing a signal representative of movement of a pump motor (which can be determined based on motor current or other methods) to pressure sensor readings, accurately predicting a component of the pressure sensor readings attributable to the pump motor by applying a threshold to various filter coefficients of the adaptive filter, and removing the contribution of the pump motor from the pressure sensor readings. After the pump motor contribution has been removed from the fluid pressure sensor readings, a residual component of the fluid pressure is attributable to patient movement, venous pressure, or other sources external to the pump. Accordingly, one or more pump settings can be adjusted based on the residual component of the fluid pressure to control delivery of fluid to a patient. Thus, an adaptive filter in combination with a pump described herein can improve control of the pump and reduce or eliminate unintended bolus, under-delivery, and / or cessation of fluid to a patient attributable to downstream pressure changes. In some embodiments, removal of the pump motor contribution to the fluid pressure signal can allow more useful information to be extracted based on the fluid pressure signal attributable to noise reduction by the pump motor. Additionally and / or alternatively, improved downstream pressure feedforward control of a pump system described herein including an adaptive filter can help reduce or eliminate the extent of bolus or under-infusion attributable to highly variable fluid delivery, and the fluid flow rate of fluid in the fluid delivery tube can quickly return to a desired flow rate in a shorter time.

[0032] Figure 1 A system diagram showing a pump system 100 is depicted in accordance with some example embodiments. Referring to Figure 1 , the pump system 100 can include a fluid reservoir 120, a pump filter system 140 including a pump (also referred to herein as an “infusion device”) 122, a filter 104, and a sensor 110, a fluid delivery tube 106 connecting the fluid reservoir 120 and the pump 122, a network 105, an accessory system 102, and a display 154. In some example embodiments, the display 154, the filter 104, the sensor 110, and / or the accessory system 102 can form a part of the pump 122 and / or can be positioned within a housing of the pump 122.

[0033] The display 154 can form a part of the pump 122, or can be separately coupled as part of a client device. The display 154 can also include a user interface. The user interface can form a part of a display screen of the display 154 that presents information to a user, and / or the user interface can be separate from the display screen. For example, the user interface can be one or more buttons or portions of a display screen configured to receive inputs from a user. The client device can be a mobile device, such as a smartphone, a tablet computer, a wearable device, and / or the like. However, it should be appreciated that the client device can be any processor-based device, including, for example, a desktop computer, a laptop computer, a workstation, and / or the like. Via the display 154, a user can configure certain parameters of the pump 122, such as filter coefficient thresholds, desired flow rates or flow rate limits, alarm limits, and / or the like. Additionally, in some examples, via the display 154, a user can configure various fluid protocols with default settings and safety parameters (e.g., set limits on dosing of fluids).

[0034] The accessory system 102 can include alarms, lights (e.g., LEDs), sound sources, and / or other indicators. The indicators can indicate to a user one or more measured values, thresholds, or other detected events related to the pump 122. For example, the indicators can indicate to a user that a fluid pressure within the fluid delivery tube 106 is greater than, less than, or equal to a threshold, a rate of change of the fluid pressure is greater than, less than, or equal to a threshold, a measured fluid pressure does not match a desired fluid pressure, a coefficient of a filter is greater than, less than, or equal to a threshold, and / or the like. As mentioned above, the accessory system 102 can form a part of the pump 122 and / or the display 154, or can be separately coupled to the pump 122, such as via the network 105.

[0035] As Figure 1 The pump filter system 140 (e.g., the pump 122, the filter 104, and / or the sensor 110), the display 154, and / or the accessory system 102 are shown communicatively coupled via a network 105. The network 105 can be any wired and / or wireless network, including, for example, a public land mobile network (PLMN), a local area network (LAN), a virtual local area network (VLAN), a wide area network (WAN), the Internet, and / or the like.

[0036] The pump 122 can be any type of pump configured to move fluid from a fluid reservoir 120 (e.g., a reservoir, a drip chamber, a syringe, etc.) through a conduit or other tubing (e.g., the fluid delivery tube 106) to a destination (not shown in the figures) (e.g., a patient). The pump 122 can be a Large Volume Infusion Pump (LVP) configured to deliver medication to a patient, a syringe pump (SP), an anesthesia delivery pump, an infusion pump, and / or a patient-controlled analgesic (PCA) pump. However, it should be appreciated that the pump 122 can be any infusion device configured to deliver a substance (e.g., a fluid, a nutrient, a medication, etc.) to a patient’s circulatory system or epidural space via, for example, intravenous infusion, subcutaneous infusion, arterial infusion, epidural infusion, etc. Additionally and / or alternatively, the pump 122 can be an infusion device configured to deliver a substance (e.g., a fluid, a nutrient, a medication, etc.) to a patient’s digestive system via a nasogastric tube (NG), a percutaneous endoscopic gastrostomy tube (PEG), a nasojejunal tube (NJ), etc. Additionally and / or alternatively, the pump 122 can include a pump coupled to a downstream pressure sensor. Further, the pump 122 can be part of a patient care system that includes one or more additional pumps.

[0037] The pump 122 can include the controller 108 and a motor 130. The motor 130 can include various types of motors, such as an electric motor, etc. The motor 130 can control a fluid flow rate of fluid to be delivered to a patient through the fluid delivery tube 106. The motor 130 can include a motor current corresponding to the fluid flow rate. The controller 108 can determine and / or control the fluid flow rate, such as a level of the fluid flow rate, a change in the fluid flow rate, and / or the like, by adjusting the current provided to the motor. For example, in some embodiments, the controller 108 receives a desired value and / or rate of change of the fluid flow rate selected via the display 154.

[0038] In some embodiments, the controller 108 can determine a value and / or rate of change of the fluid flow rate based at least in part on one or more sensor readings from the sensor 110. The sensor 110 can be coupled with the pump 122 and / or the filter 104. The sensor 110 can include a downstream pressure sensor positioned on or near the patient, for example at or near the fluid delivery site. In some embodiments, the sensor 110 measures a fluid pressure of the fluid within the fluid delivery tube 106. The sensor 110 can take fluid pressure readings continuously and / or at various time intervals (e.g., every 10 seconds, every 30 seconds, every 1 minute, every 30 minutes, every 1 hour, every 12 hours, every 24 hours, etc.). In some embodiments, the controller 108 controls when the sensor 110 measures the fluid pressure. The sensor 110 can transmit the fluid pressure readings to the filter 104 and / or to the pump 122 (e.g., the controller 108). As described above, the fluid pressure can include one or more pressure signals caused by one or more components of the pump system 100, patient movement, venous pressure, and / or the like. In some embodiments, the controller 108 can communicate with one or more other systems, such as the accessory system 102, the display 154, and / or the filter 104.

[0039] The filter 104 can include one or more digital and / or analog filters. For example, the filter 104 can include an adaptive filter, as described above, which can help separate contributing factors to the fluid pressure signal, such as pump contributions, patient contributions, and / or the like. The adaptive filter 104 can be able to adjust (e.g., continuously and / or at various time intervals) various coefficients of the filter to adapt or otherwise improve the accuracy of the fluid pressure signal. For example, in some embodiments, the filter 104 described herein can help reduce or eliminate noise generated by the pump 122 (e.g., the motor 130 of the pump 122) from the fluid pressure signal to provide the fluid pressure signal caused by patient movement, venous pressure, and / or the like. In other words, the filter 104 described herein can accurately provide a fluid pressure signal that does not include noise (or pressure signals) caused by the pump 122 (e.g., the motor 130 of the pump 122). In some embodiments, as described in greater detail below, the filter 104 can include a least means square (“LMS”) predictor to further improve the accuracy of the fluid pressure signal. Accordingly, the pump system 100 including the filter 104 can desirably improve feedforward control of the pump and reduce unintended bolus, under-delivery, and / or cessation of fluid delivery to the patient.

[0040] Figure 2 A flowchart is shown schematically illustrating the operation of the pump filter system 140. Figures 3A-3CVarious graphs showing examples of signals that can be measured by one or more sensors, etc. (e.g., sensors 110) and / or calculated by the pump filter system 140 (e.g., by the controller 108 of the pump 122) are shown. Figures 4A-4B An example of a filter 104 consistent with implementations of the current subject matter is shown schematically.

[0041] Referring to Figure 2 At 230, a motor current 202 is supplied to the motor 130 of the pump 122. The amount of motor current 202 supplied to the motor 130 can be controlled by the controller 108. In some implementations, the amount of motor current 202 supplied to the motor 130 can be measured by one or more sensors. In other implementations, the amount of motor current 202 supplied to the motor 130 can be detected using a back end Electromagnetic Field (“EMF”) reader, a motor current sensor, a motor torque sensor, and / or the like. Figure 3A A graph showing a signal including a plurality of motor currents 202 over a period of time (e.g., approximately 16 seconds) at 230 is shown. As explained in greater detail below, the signal representing the motor current 202 can be used by the controller 108 and / or the filter 104 to remove the contribution of the motor to the fluid pressure in the fluid delivery tube 106.

[0042] At 240, the sensors 110 (e.g., one or more pressure sensors) can measure a fluid pressure of the fluid within the fluid delivery tube 106. The sensors 110 can be positioned downstream relative to the pump 122. In some implementations, the sensors 110 can be positioned on or near the patient, e.g., at or near the fluid delivery site. The sensors 110 can take fluid pressure readings continuously and / or at various time intervals (e.g., every 10 seconds, every 30 seconds, every 1 minute, every 30 minutes, every 1 hour, every 12 hours, every 24 hours, etc.). In some implementations, the controller 108 controls the time at which the sensors 110 measure the fluid pressure. The sensors 110 can also transmit the fluid pressure readings to the filter 104 and / or to the pump 122 (e.g., the controller 108). The fluid pressure (and components of the fluid pressure, e.g., motor pressure and patient pressure) can include one or more fluid pressure measurements. In some implementations, the fluid pressure can be defined by a fluid pressure signal including one or more fluid pressure measurements. In some implementations, the fluid pressure can be defined by a value representing the fluid pressure signal.

[0043] The fluid pressure can include one or more pressure signals caused by one or more components of the pump system 100, patient movement, venous pressure, and / or the like. In some implementations, as Figure 2 and Figure 3BAs shown in the middle, the fluid pressure reading can be a combination of at least the motor pressure 204 and the patient pressure 206. For example, the motor pressure 204 can form a first component of fluid pressure caused by the motor 130 of the pump 122. The motor 130 generates a torque that is proportional to the motor current 202 supplied to the motor 130. The torque generated by the motor 130 generates a first component of fluid pressure (e.g., motor pressure 204) within the fluid delivery tube 106. The patient pressure 206 can form another component of fluid pressure caused by the patient. For example, the patient’s movement, the patient’s venous pressure, and / or the like can generate a patient pressure 206 of fluid pressure within the fluid delivery tube 106. Thus, the fluid pressure is a combination of one or more pressures generated by different sources. For example, Figure 3B The fluid pressure signal, the patient pressure signal, and the motor pressure signal are shown graphically. For example, as shown in the left, the fluid pressure (e.g., fluid pressure signal) at 240 can be a combination of the motor pressure 204 (e.g., motor pressure signal) and the patient pressure 206 (e.g., patient pressure signal). As shown, the motor pressure 204 has a similar graphical appearance as the motor current 202 because the motor torque is proportional to the motor current 202 supplied to the motor 130. Figure 3B

[0044] As shown in the middle, the motor current 202 and the fluid pressure reading 212 can be transmitted (through a wired and / or wireless connection) to the filter 104, which can determine the value of the patient pressure 206 (e.g., the recovered patient pressure 210) at 250 by generating the predicted motor pressure 208 and removing the predicted motor pressure 208 from the fluid pressure reading 212. Figure 2

[0045] Figure 4A and Figure 4B ​​An example of filter 104 consistent with an embodiment of the present subject is schematically depicted. As noted above, filter 104 may include digital and / or analog adaptive filters to separate factors contributing to fluid pressure, such as motor pressure 204 and patient pressure 206. For example, filter 104 may initially receive and store one or more motor current measurements (e.g., motor current 202 and / or motor torque). The motor current 202 measurement may be loaded into shift register 402 of filter 104 with a motor current sample size of n+1, where n equals the previous number of motor current measurements. In some embodiments, for example, the motor current sample size is equal to 10 to 20 motor current measurements, which may be acquired continuously and / or at predetermined time intervals. In some implementations, the motor current sample size is equal to 5 to 10 previous motor current measurements, 10 to 15 previous motor current measurements, 15 to 20 previous motor current measurements, 20 to 25 previous motor current measurements, 10 previous motor current measurements, 15 previous motor current measurements, 20 previous motor current measurements, and / or other ranges therebetween. As an example, Figure 4A The motor current measurement applied to shift register 402 is shown at position 450. The filter 104 is also shown. Figure 4A Each of the motor current measurement values ​​is represented as X. t X t-1 X t-2 X t-3 X t- 4...X t-n .

[0046] Next, filter 104 (or controller 108) can determine a portion of the fluid pressure attributable to patient pressure 206 by removing (e.g., filtering) motor pressure 204 from fluid pressure reading 212. In some embodiments, filter 104 may generate a first predicted motor pressure based on a motor current measurement applied to shift register 402. For example, filter 104 may use the following equation to determine the first predicted motor pressure.

[0047] Equation 1: ∑(X t…t-n (k) 1…m )=∑(Y t…t-n )

[0048] As mentioned above, X t…t-n This represents each of the measured motor current values. Figure 4A At position 460 shown, each of the motor current measurements stored in the shift register of filter 104 is passed through the corresponding coefficients k1...k. m Scaling is performed. Each scaling result is determined by Y. t…t-n It indicates that it is combined to provide the first predicted motor pressure.

[0049] At 470, filter 104 (or controller 108) can compare the first predicted motor pressure with the fluid pressure measured by sensor 110. Controller 108 can compare the first predicted motor pressure with the measured fluid pressure by obtaining the difference between the first predicted motor pressure and the measured fluid pressure. At 480, the difference between the first predicted motor pressure and the measured fluid pressure is equivalent to an error signal (see [link to error signal]). Figure 4B This represents the fluid pressure without motor pressure. In other words, once the first predicted motor pressure and fluid pressure readings converge, the error signal equals the actual patient pressure (the residual component of the fluid pressure after the motor pressure has been removed). The convergence between the first predicted motor pressure and the fluid pressure reading over time indicates an accurate representation of the fluid pressure determined to be attributable to the patient pressure. Figure 3C An example of convergence is shown below. Figure 3C As shown, at 250, the predicted motor pressure and fluid pressure readings begin to converge after approximately 6 seconds. Once the predicted motor pressure and fluid pressure readings converge, the patient pressure signal is graphically represented by lines with minimal variation (e.g., the peaks and troughs of each fluctuation are within the range of 0 to 0.5%, 0.5% to 1.0%, 1.0% to 1.5%, 1.5% to 2.0%, 2.0% to 3%, or in between).

[0050] The error signal, determined at 480, is used before the predicted motor pressure and fluid pressure readings converge to define the patient pressure (see [reference]). Figure 4B This can be used to update the tap update coefficient α of filter 104 at position 490 (see...). Figure 4B The tap update coefficient α can be updated based on the error signal of the LMS predictor of filter 104 to minimize the minimum mean square error of the error signal. However, in some embodiments, the tap update coefficient can be constant. The LMS predictor of filter 104 can additionally and / or alternatively update the error signal by applying the tap update coefficient α to the error signal and combining the scaled error signal with the value X for the motor current measurement. t…t-n The filter coefficients k1...k in each of them m This is used to scale the error signal. Accordingly, in some implementations, the error signal can be determined using the following equation:

[0051] Equation 2: Scaled error signal = (error signal * α) + k 1…m

[0052] Additionally, using the scaled error signal, filter 104 can determine the predicted motor pressure using the following equation:

[0053] Equation 3: α*∑(X t…t-n)(k 1…m ) = ∑(Y t…t-n )

[0054] In some implementations, filter 104 (e.g., via controller 108) can apply various thresholds to filter coefficients k1...k m to determine a state of pump system 100. For example, filter coefficients k1...k m may be updated until an error value representing an error signal (or a scaled error signal) is less than or equal to an error threshold. In some implementations, the error value is a minimum mean square of the error signal (or the scaled error signal), a norm representing the error signal (or the scaled error signal), and / or the like. The error threshold can be 0.1 to 0.2, 0.2 to 0.3, 0.3 to 0.4, or higher. For example, if the error value is greater than or equal to the error threshold, filter 104 can update or otherwise change filter coefficients k1...k m , which can then be applied to motor current measurements. In contrast, if the error value is less than the error threshold, filter 104 can stop updating filter coefficients k1...k m . In this case, the error signal will be equal to the patient pressure, and the predicted motor value will be equal to the actual motor pressure.

[0055] In some implementations, filter 104 (e.g., via controller 108) iterates through various filter coefficients to minimize an error value representing an error signal, thereby providing an estimate of a predicted motor pressure value. For example, if an error signal generated between a first predicted motor pressure value and a fluid pressure reading is greater than or equal to an error threshold within a threshold number of cycles (e.g., one, two, three, four, five, ten, fifteen, twenty, or more iterations), filter 104 can update filter coefficients k1...k m . If an error signal generated between a next predicted motor pressure value determined based on the updated filter coefficients k1...k m and the fluid pressure reading is still greater than or equal to the error threshold after the next iteration, filter 104 can continue to update filter coefficients k1...k m .

[0056] Filter 104 can continue to iterate through various filter coefficients until the error value is less than the error threshold and / or until a number of iterations of filter 104 has reached the threshold number of cycles. For example, filter 104 can iterate through various filter coefficients k1...k m by incrementing filter coefficients k1...k m. Filter 104 can increment filter coefficients k1...k m by a set amount for each iteration (e.g., 0.1, 0.2, 0.3, 0.4, and the like). In other embodiments, filter 104 can dynamically increment filter coefficients k1...k m for each iteration based on the size of the error value relative to the error threshold. For example, when there is a large difference between the error value and the error threshold (e.g., the difference is greater than or equal to 0.2, 0.3, 0.4, and / or the like), filter 104 can increment filter coefficients k1...k m by a larger or smaller amount, and when there is a small difference between the error value and the error threshold (e.g., the difference is less than or equal to 0.2, 0.15, and the like), filter 104 can increment filter coefficients k1...k m by a larger or smaller amount, for example when the predicted motor pressure value and the measured fluid pressure are close to converging.

[0057] In some embodiments, after convergence (e.g., when the error value is less than the error threshold), the resulting transfer function including the filter coefficients at convergence can accurately represent the relationship between motor current and pressure sensor readings. In other words, the resulting filter coefficients at convergence can be considered a numerical representation of the motor pressure to fluid pressure transfer function. The transfer function can be used by controller 108 to determine various parameters of various components of pump system 100, such as motor 130, motor sensors, pump 122, fluid delivery tube 106, sensor 110, and / or the like.

[0058] Alternatively, if the error value does not fall below the error threshold for a threshold number of cycles, the controller 108 can ignore the predicted motor pressure value and instead rely on the fluid pressure including both the motor pressure 204 and the patient pressure 206 to adjust one or more settings of the pump 122 (as described in greater detail below). In some embodiments, if the error value does not fall below the error threshold for a threshold number of cycles, the controller 108 of the pump 122 can adjust a user interface, light, or audio component to present a human perceptible indication that the total fluid pressure of the fluid in the fluid delivery tube is being used by the controller 108 to adjust one or more settings of the pump 122. As another example, when the error value does not fall below the error threshold for a threshold number of cycles, the pump 122 can deactivate the pumping mechanism or engage a flow restrictor to prevent fluid from flowing from the fluid delivery tube to the patient. In some embodiments, the pump 122 can communicate with a local or wireless accessory system (e.g., the accessory system 102), for example, via the display 154 of the pump or a separate client device, to indicate that the total fluid pressure of the fluid in the fluid delivery tube is being used by the controller 108 to adjust one or more settings of the pump 122 and / or that the pump is preventing fluid from flowing to the patient. For example, the pump 122 can display an indicator, such as an alarm, text, a flashing light, etc.

[0059] In some embodiments, the filter 104 can track the filter coefficients kl...k m (e.g., via the controller 108) over time. Tracking the filter coefficients kl...k m may provide useful information about the status of the pump system 100 (e.g., about the pump 122). For example, changes (e.g., increases or decreases) in the filter coefficients over time can indicate that the pump system 100 is malfunctioning, needs preventative maintenance or service on the pump system 100, and / or the like. Additionally and / or alternatively, sudden changes (e.g., increases or decreases) in the filter coefficients can indicate that the pump system 100 is malfunctioning, needs preventative maintenance or service on the pump system 100, and / or the like. When the controller 108 determines that the pump system 100 is malfunctioning and / or needs preventative maintenance or service on the pump system 100, the pump 122 can display an indicator as described herein and / or otherwise deactivate the pump 122.

[0060] Based on the filtered fluid pressure (e.g., the fluid pressure of the motorless pressure 204), the controller 108 can adjust one or more settings of the pump 122, e.g., the speed or rate of fluid flow, the amount of fluid delivered to the patient, the type of fluid delivered to the patient, and / or the like. The pump system 100 including the filter 104 described herein can desirably more accurately adjust one or more settings of the pump 122 based on more accurate fluid pressure readings. This helps to improve the feedforward control of the pump 122 and reduce or eliminate unintended bolus, under-delivery, and / or cessation of fluid flow within the fluid delivery tube 106 due to changes in fluid pressure.

[0061] Figure 5 A flowchart depicting a process 560 for adjusting pump settings based on a patient pressure component of fluid pressure is depicted.

[0062] At 562, a pressure sensor (e.g., the sensor 110) can measure a fluid pressure of a fluid in a fluid supply line (e.g., the fluid delivery tube 106) of a fluid pump (e.g., the pump 122), such as an infusion pump. The fluid pressure can include pressure caused by one or more components of the pump and / or movement of the patient. For example, the fluid pressure can include a motor pressure caused at least in part by a current of a motor (e.g., the motor 130) of the pump. In some embodiments, the fluid pressure can additionally and / or alternatively include a patient pressure caused at least in part by movement of the patient. The fluid pressure can additionally and / or alternatively include pressure caused by one or more other sources, such as a venous pressure of the patient, movement of the pump, movement of the fluid supply line, and / or movement of one or more other components of the pump.

[0063] As described above, it can be desirable to remove motor pressure from the fluid pressure to allow the pump (e.g., via a controller, such as the controller 108) to more accurately and reliably deliver fluid (e.g., a desired fluid flow rate, an amount of fluid, etc.) to the patient. For example, at 564, a controller coupled to the pressure sensor can determine a patient pressure. The controller can accurately and / or reliably determine one or more settings of the pump based on the patient pressure or at least by removing motor pressure from the fluid pressure. To determine the patient pressure of the fluid pressure, an adaptive filter (e.g., the filter 104) coupled to the pressure sensor and the controller can be used to effectively remove motor pressure from the measured fluid pressure. In some embodiments, the adaptive filter is a digital and / or analog adaptive filter. As described herein, the adaptive filter can iterate through various filter coefficients over multiple cycles to filter and remove motor pressure from the fluid pressure.

[0064] At 566, to remove the motor pressure from the measured fluid pressure, the adaptive filter and / or controller can generate a predicted motor pressure based on the motor's current. For example, a back EMF reader, a motor current sensor, a motor torque sensor, and / or the like can measure one or more motor currents continuously and / or at predetermined time intervals over a period of time, such as 10 to 20 seconds. In some implementations, 10 to 20 motor current measurements are taken and recorded by the back EMF reader, the motor current sensor, the motor torque sensor, and / or the like. The motor current measurements can be stored in a data store, such as a shift register (e.g., shift register 402) of filter 104.

[0065] In some implementations, the predicted motor pressure can be determined by applying one or more filter coefficients to each of the motor current measurements stored on the shift register and combining the scaled motor current measurements. In other words, the combination of the motor current measurements scaled by the filter can represent the initial predicted motor pressure.

[0066] At 568, the adaptive filter and / or controller can generate an error signal based on a comparison between the predicted motor pressure and the measured fluid pressure. For example, the adaptive filter and / or controller can take the difference between the predicted motor pressure and the measured fluid pressure to determine the error signal. As noted above with respect to Figures 1 to 4B As noted above, when the predicted motor pressure and the fluid pressure signals converge, the error signal represents the patient pressure component of the fluid pressure (see Figure 3C In other words, when there is minimal change between the predicted motor pressure and the fluid pressure signal, the error signal represents the patient pressure component of the fluid pressure.

[0067] At 570, when an error value representing the error signal is less than an error threshold, the adaptive filter and / or controller can remove the motor pressure from the measured fluid pressure. For example, the error value can be a norm of the error signal, a least mean square of the error signal, and / or another value representing the error signal. In some implementations, a tap filter coefficient is applied to the error signal and combined with the filter coefficients to determine the error value. In some implementations, the tap filter coefficient can be applied to the error signal and combined with the filter coefficients by an LMS predictor of the adaptive filter. The tap filter coefficient can be constant over multiple cycles or can be dynamically updated after each cycle (e.g., after each iteration).

[0068] In some implementations, removing the motor pressure from the measured fluid pressure includes first determining whether the error value is less than an error threshold. For example, the filter and / or controller can compare the error value to the error threshold. Based on the comparison between the error value and the error threshold, the filter and / or controller can determine that the error value is greater than or equal to the error threshold, as an example. When the error value is greater than or equal to the error threshold, one or more filter coefficients can be adjusted, and the adjusted filter coefficients can be applied to the motor current measurements. For example, the filter coefficients can be incremented by a predetermined amount and / or can be dynamically updated based on the magnitude of the difference between the error value and the error threshold. The filter and / or controller can then generate an updated predicted motor pressure based on the adjusted filter coefficients and the current of the motor. The filter and / or controller can continue to iterate through and adjust the values of the filter coefficients until the filter and / or controller determines that the error value is less than the error threshold and / or until a predetermined number of iterations (e.g., loops) have been performed. When the error value is less than the error threshold, the error signal is approximately equal to the desired patient pressure.

[0069] If the predetermined number of iterations have been performed before the filter and / or controller determines that the error value is less than the error threshold, the pump system can make a change to a parameter of the fluid delivery (e.g., fluid flow rate, amount of fluid delivered, type of fluid delivered, etc.) based on the measured fluid pressure. In such cases, the controller can communicate with the accessory system to display an indicator, such as an alarm, text, a flashing light, and / or the like. In some implementations, when the error value does not fall below the error threshold within a threshold number of iterations, the controller can deactivate the pumping mechanism or engage a flow restrictor to stop fluid from flowing from the fluid delivery tube to the patient.

[0070] At 572, the controller can adjust one or more settings of the pump based at least in part on the determined patient pressure (e.g., the fluid pressure with the motor pressure removed). For example, the controller can adjust one or more settings of the pump, such as the speed or delivery rate of fluid flow, the amount of fluid delivered to the patient, the type of fluid delivered to the patient, and / or the like. Pump systems including the adaptive filter described herein can desirably accurately adjust one or more settings of the pump based on more accurate fluid pressure readings, which helps to improve feedforward control of the pump and reduce or eliminate unintended bolus, under-delivery, and / or cessation of fluid flow in the fluid delivery tube due to changes in fluid pressure.

[0071] Figure 6 A block diagram illustrating a computing system 500, consistent with implementations of the current subject matter, is depicted. Reference is made to Figure 1 and Figure 6The computing system 500 can be used to implement the pump filter system 140 (including the pump 122, the filter 104, and the pressure sensor 110), the accessory system 102, the display 154, and / or any components therein.

[0072] As shown in Figure 6 The computing system 500 can include a processor 510, a memory 520, a storage device 530, and an input / output device 540. The processor 510, the memory 520, the storage device 530, and the input / output device 540 can be interconnected via a system bus 550. The processor 510 is capable of processing instructions for execution within the computing system 500. Such instructions can be embodied in one or more components as the pump 122. In some example embodiments, the processor 510 can be a single-threaded processor. Alternatively, the processor 510 can be a multi-threaded processor. The processor 510 is capable of processing instructions stored in the memory 520 and / or on the storage device 530 to present graphical information for a user interface provided via the input / output device 540.

[0073] The memory 520 is a computer readable medium, for example, volatile or non-volatile, within the computing system 500 that stores information. The memory 520 can store, for example, data structures representing configuration objects. The storage device 530 is capable of providing long-term storage for the computing system 500. The storage device 530 can be a floppy disk device, a hard disk device, an optical disk device, or a tape device, or other suitable non- transitory storage device. The input / output device 540 provides input / output operations for the computing system 500. In some example embodiments, the input / output device 540 includes a keyboard and / or pointing device. In various embodiments, the input / output device 540 includes a display unit for displaying a graphical user interface.

[0074] According to some example embodiments, the input / output device 540 can provide input / output operations for a network device. For example, the input / output device 540 can include an Ethernet port or other networking port to communicate with one or more wired and / or wireless networks (e.g., a local area network (LAN), a wide area network (WAN), the Internet).

[0075] In some example embodiments, the computing system 500 can be used to execute various interactive computer software applications that can be used for organization, analysis, and / or storage of data in various formats. Alternatively, the computing system 500 can be used to execute software applications. These applications can be used to perform various functions, such as planning functions (e.g., creating, managing, editing spreadsheet documents, word processing documents, and / or any other objects, etc.), calculating functions, communication functions, etc. The applications can include various plug-in functions, or can be standalone computing products and / or functions. Upon activation within an application, the functions can be used to generate a user interface that is provided via the input / output devices 540. The user interface can be generated by the computing system 500 and presented to the user (e.g., on a computer screen monitor, etc.).

[0076] In some example embodiments, the pump 122 (e.g., a pump 22 as shown in Figures 7A to 7C FIG. 1) can be part of a patient care system 20. Figures 7A to 7C An example embodiment of a patient care system 20 is shown, but other types of patient care systems can be implemented. With reference to Figure 7A , the patient care system 20 can include a pump 22 as well as additional pumps 24, 26, and 28. Although a large volume pump (LVP) is shown, other types of pumps can be implemented, such as a small volume pump (SVP), a syringe pump, an anesthesia delivery pump, and / or a patient controlled analgesia (PCA) pump configured to deliver medication to a patient. The pump 22 can be any infusion device configured to deliver a substance (e.g., a fluid, a nutrient, a medication, etc.) to a patient's circulatory system or epidural space via, for example, intravenous infusion, subcutaneous infusion, arterial infusion, epidural infusion, etc., or the pump 22 can be an infusion device configured to deliver a substance (e.g., a fluid, a nutrient, a medication, etc.) to a patient's digestive system via a nasogastric tube (NG), a percutaneous endoscopic gastrostomy tube (PEG), a nasojejunal tube (NJ), etc.

[0077] As Figure 7AAs shown in FIG. 1, each of the pumps 22, 24, 26, and 28 can be fluidly connected to an upstream fluid line 30, 32, 34, and 36, respectively. In addition, each of the four pumps 22, 24, 26, and 28 can also be fluidly connected to a downstream fluid line 31, 33, 35, and 37, respectively. The fluid lines can be any type of fluid conduit through which fluid can flow, such as a fluid delivery tube (e.g., fluid delivery tube 106). At least a portion of one or more of the fluid lines can be constructed with a multi-layer configuration as described herein. In some embodiments, each of the pumps 22, 24, 26, and 28 can use the same fluid line. In such embodiments, the pump system can detect the time various types of fluid flow through the fluid line as described above. In some embodiments, the pump 22 can be coupled to an adaptive filter (e.g., filter 104) that can remove various components of the fluid pressure measured from within the fluid delivery tube, such as motor pressure caused by operation of the motor of the pump. This helps to improve the feedforward control of the pump and reduce unintended bolus, under-delivery, and / or cessation of fluid delivery to the patient.

[0078] The fluid supplies 38, 40, 42, and 44 (e.g., fluid reservoirs 120), which can be in the form of various forms but are shown in this case as bottles, are inverted and suspended above the pumps. The fluid supplies can also be in the form of a bag, a syringe, or other type of container. Both the patient care system 20 and the fluid supplies 38, 40, 42, and 44 can be mounted to a roller stand or an intravenous (IV) pole 46.

[0079] Separate pumps 22, 24, 26, and 28 can be used to infuse each of the fluids of the fluid supplies into the patient. The pumps 22, 24, 26, and 28 can be flow control devices that will act on the respective fluid lines to move fluid from the fluid supplies through the fluid lines to the patient 48. Because separate pumps are used, each pump can be individually set to the pumping or operating parameters necessary to infuse each fluid from the respective fluid supply to the patient at the specific rate prescribed by the physician for that particular medical fluid. Such medical fluids can include a medication or a nutrient or other fluid.

[0080] Typically, medical fluid administration devices have more parts than Figure 7A shown in FIG. 1. Many devices have check valves, drip chambers, valved ports, connectors, and other devices well known to those skilled in the art. These other devices have not been included in the drawings in order to maintain clarity of the illustration. In addition, it should be noted that Figure 7A the drawings of FIG. 1 are not drawn to scale, and distances have been reduced for clarity. In an actual setting, the distances between the fluid supplies 38, 40, 42, and 44 and the pump modules 22, 24, 26, and 28 can be much greater.

[0081] Referring now to Figure 7BFIG. 1 shows a front view of a patient care system 20. FIG. 2 shows an enlarged view of the front of the patient care system 20. The pump 22 can include a front door 50 and a handle 52 that is operated to lock the door in a closed position for operation, and to unlock and open the door to access the internal pumping and sensing mechanisms and to load an administration set for the pump. When the door is open, a tube (e.g., a fluid delivery tube 106) can be connected with the pump, as will be shown in Figure 7C FIG. 3. When the door is closed, the tube is in operative engagement with the pumping mechanism, upstream and downstream pressure sensors, and other equipment of the pump. In this embodiment, a display 54 (e.g., display 154), such as an LED display, is located in the planar view on the door, and can be used to visually communicate various information related to the pump, such as warning indications (e.g., alarm messages). The display 54 can additionally be part of or coupled to the pump 22. There are control keys 56 for programming and controlling the operation of the pump as desired. The pump 22 also includes an audio alarm device in the form of a speaker (not shown in the figures).

[0082] In the embodiment shown, a programming module 60 is attached to the left side of the pump 22. In some embodiments, the programming module 60 forms part of the pump 22. Other devices or modules, including another pump, can be attached to the right side of the pump 22, as shown in Figure 7A FIG. 4. In such a system, each attached pump represents a pumping channel of the overall patient care system 20. In one embodiment, the programming module is used to provide an interface between the pump 22 and external devices, as well as to provide most of the operator interface for the pump 22.

[0083] The programming module 60 includes a display 62 for visually communicating various information, such as operating parameters of the pump 22, as well as warning indications and alarm messages. The programming module 60 can additionally and / or alternatively communicate with the accessory system 102 to, for example, indicate that the predicted motor pressure and measured fluid pressure have not converged (e.g., the error value is not less than the error threshold after a threshold number of cycles). The programming module 60 can additionally and / or alternatively display one or more parameters of the fluid, such as the fluid pressure of the fluid in the fluid delivery tube (e.g., the fluid delivery tube 106), the patient pressure, and / or the motor pressure, on the display 54. The programming module 60 can also include a speaker to provide audible alarms. The programming module or any other module also has various input devices in this embodiment, including control keys 64 and a bar code or other scanner or reader for scanning information from electronic data tags relating to the infusion, the patient, the caregiver, or others. The programming module also has a communication system (not shown) that can communicate with external equipment, such as a medical facility server or other computer, and with a portable processor, such as a hand-held portable digital assistant ("PDA") or a laptop computer, or other information device that a caregiver can have, to transfer information and to download drug libraries to the programming module or the pump.

[0084] The communication system can be in the form of a radio frequency ("RF") system, an optical system such as infrared, a Bluetooth system, or other wired or wireless system. The bar code scanner and the communication system can alternatively be integrated with the pump 22, such as in the case where the programming module is not used, or in addition to being integrated with the pump, can be integrated with the programming module. Furthermore, the information input devices need not be hard-wired to the medical device, but can transfer information via a wireless connection.

[0085] Figure 7B A second pump 26 is included that is connected to the programming module 60. As shown in Figure 7A more pump modules can be connected. Additionally, other types of modules can be connected to the pump module or the programming module.

[0086] Reference is now made to Figure 7C to show the pump 22 in perspective with the front door 50 open to show the upstream fluid line 30 and the downstream fluid line 31 in operative engagement with the pump 22. The pump 22 acts directly on a tube 66 (also referred to as a pump segment) that connects the upstream fluid line 30 to the downstream fluid line 31 to form a fluid path from the respective fluid supply 38 Figure 7A) a continuous fluid conduit extending to the patient 48 through which the pump acts on the fluid to move the fluid downstream to the patient. In particular, the pumping mechanism 70 acts as a flow control device for the pump to move the fluid through the conduit. The upstream and downstream fluid lines and / or tubing 66 can be coupled to a pump cartridge or barrel configured to be coupled to the pump 22, such as the type described in co-pending U.S. Patent Application No. 13 / 827,775, which is incorporated herein by reference.

[0087] The type of pumping mechanism can vary and can be, for example, a multi-finger pumping mechanism. For example, the pumping mechanism can be of the "four-finger" type and include an upstream occlusion finger 72, a primary pumping finger 74, a downstream occlusion finger 76, and a secondary pumping finger 78. The "four-finger" pumping mechanism and mechanisms used in other linear peristaltic pumps operate by sequentially pressing against a segment of the fluid conduit by means of cam-following pumping and valve fingers 72, 74, 76, and 78. Pressure is applied in sequential positions of the conduit, starting from the upstream end of the pumping mechanism and working toward the downstream end. At least one finger is always pressing hard enough to occlude the conduit. As a practical matter, one finger does not retract without occluding the fluid delivery tube until the next finger in sequence has occluded the fluid delivery tube; thus, there is no direct fluid path from the fluid supply to the patient at any time. The operation of peristaltic pumps including four-finger pumps is well known to those of skill in the art, and further operational details are not provided here.

[0088] In this particular implementation, Figure 7C A downstream pressure sensor 82 is further shown included in the pump 22 at a downstream position relative to the pumping mechanism. The downstream pressure sensor 82 is mounted to and located in the vicinity of and downstream of the flow control device 70. The downstream pressure sensor is located downstream of the flow control device, i.e., at a position between the patient 48( Figure 7A ) and the flow control device, so that the connection of the correct fluid supply to the correct pump can be verified before any fluid is pumped to the patient. In some implementations, the fluid pressure measured by the downstream pressure sensor 82, which can include a sensor 110, can be filtered by an adaptive filter, such as filter 104, to remove various components of the measured fluid pressure, such as motor pressure caused by the motor operation of the pump. This helps to improve the feedforward control of the pump and reduce unintended bolus delivery, under-delivery, and / or cessation of fluid to the patient.

[0089] Still referring to Figure 7CAn upstream pressure sensor 80 can also be included in the pump 22. The upstream pressure sensor is assigned to the flow control device or pumping mechanism 70, and in this embodiment, is further provided as a component of the pump 22. The upstream pressure sensor is mounted to and located in the vicinity of and upstream of the flow control device 70. The upstream pressure sensor is located upstream of the flow control device, i.e., at a location between the fluid supply 38( Figure 7A ) and the flow control device, such that the connection of the correct fluid supply to the correct pump can be verified before any fluid is pumped to the patient. In embodiments where the source is a syringe, the flow control device 70 can be configured to press the plunger of the syringe to provide infusion according to programmed parameters.

[0090] One or more aspects or features of the subject matter described herein can be realized in digital electronic circuitry, integrated circuitry, specially designed ASICs, field programmable gate arrays (FPGAs) computer hardware, firmware, software, and / or combinations thereof. These various aspects or features can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device. The programmable system or computing system can include clients and servers. The clients and servers are remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

[0091] These computer programs, also referred to as programs, software, software applications, applications, components, or code, include machine instructions for a programmable processor, and can be implemented in a high-level procedural and / or object-oriented programming language, and / or in assembly / machine language. As used herein, the term "machine-readable medium" refers to any computer program product, apparatus and / or device, e.g., magnetic discs, optical disks, memory, and Programmable Logic Devices (PLDs), used to provide machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal used to provide machine instructions and / or data to a programmable processor. The machine-readable medium can store such machine instructions non-volatilely, such as non-volatile solid-state memory or magnetic hard disk drives, or any equivalent storage medium. The machine-readable medium can alternatively or additionally store such machine instructions in a volatile manner, such as a processor cache or other random access memory associated with one or more physical processor cores.

[0092] To provide for interaction with a user, one or more aspects or features of the subject matter described herein can be implemented on a computer having a display device, e.g., a cathode ray tube (CRT) or a liquid crystal display (LCD) or a light emitting diode (LED) monitor for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. Other possible input devices include touch screens or other touch-sensitive devices, voice-recognized hardware and software, optical scanners, optical pointers, digital image capture devices and associated interpretation software, and the like.

[0093] In the descriptions above and in the claims, phrases such as "at least one of" or "one or more of" can occur followed by a conjunctive list of elements or features. The term "and / or" can also occur in a similar context. Unless otherwise managed by the context, this is intended to mean that at least one of the elements or features of the conjunctive list is present in the list. In other words, the phrase "at least one of A and B" is intended to mean A alone, B alone, or A and B together. The term "comprising", used in the descriptions above and in the following claims, should not be interpreted as meaning that the steps, elements or features following the term are essential only. Conjunctive language such as the phrase "at least one of is used to present

[0094] As used herein, a "user interface" (also referred to as an interactive user interface, graphical user interface, or UI) can refer to a web-based interface that includes data fields and / or other control elements for receiving input signals or providing electronic information and / or for providing information to a user in response to any received input signals. Control elements can include dials, buttons, icons, selectable areas, or other perceptible indicia presented via the UI that, when interacted with (e.g., clicked, touched, selected, etc.) the UI initiates a data exchange with the device presenting the UI. HyperText Markup Language (HTML), FLASH TM , JAVA TM ,.NETTM Technologies such as web services or Rich Site Summary (RSS) implement the UI in whole or in part. In some embodiments, the UI can be included in a standalone client (e.g., thick client, fat client) that is configured to communicate (e.g., send or receive data) according to one or more aspects described. The communication can be to or from a medical device or server in communication therewith.

[0095] As used herein, the term "determining out" or "determining" encompasses a wide variety of actions. For example, "determining" can include calculating, computing, processing, deriving, generating, obtaining, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like via a hardware element based at least in part on

[0096] As used herein, the term "providing with" or "providing" encompasses a wide variety of actions. For example, "providing" can include storing values in a location of a storage device for subsequent retrieval, transmitting the values directly to a recipient via at least one wired or wireless communication medium, transmitting or storing a reference to the values, and the like via a hardware element. "Providing" can also include encoding, decoding, encrypting, decrypting, authenticating, verifying, and the like via a hardware element.

[0097] As used herein, the term "message" encompasses a wide variety of formats for transmitting (e.g., emitting or receiving) information. A message can include a machine-readable collection of information such as an XML file, a fixed field message, a comma separated message, and the like. In some embodiments, a message can include a signal for transmitting one or more representations of information. While recited in the singular, it is understood that a message can be combined, transmitted, stored, received, and the like in multiple parts.

[0098] As used herein, the term "corresponding" or "corresponding to" encompasses a structural, functional, quantitative, and / or qualitative relationship or correlation between two or more objects, data sets, information, and / or the like, preferably where the correspondence or correlation can be used to transform one or more of the two or more objects, data sets, information, and / or the like, thus rendering as identical or equivalent. The correspondence can be assessed using one or more of a threshold, a range of values, fuzzy logic, pattern matching, a machine learning assessment model, or a combination thereof.

[0099] In any embodiment, data generated or detected can be forwarded to a "remote" device or location, where "remote" means a location or device other than the location or device where the program is executed. For example, the remote location can be another location (e.g., office, laboratory, etc.) in the same city, another location in a different city, another location in a different state, another location in a different country, etc. Thus, when one item is indicated to be "remote" from another item, this means that the two items can be in the same room but separated, or at least in different rooms or different buildings, and can be separated by at least one mile, ten miles, or at least one hundred miles. "Transmitting" information means transferring data representing the information as electrical signals over a suitable communication channel (e.g., private or public network). "Forwarding" an item means any method of moving the item from one location to the next, whether by physically transporting the item or otherwise (where possible) enabling the item to move from one location to the next, and includes, at least in the case of data, physically transporting a medium carrying the data or transmitting the data, where examples of transmission media include wireless or infrared transmission channels as well as network connections to another computer or networking device, and the Internet or information contained on a website, among others.

[0100] The subject matter described herein can be embodied in systems, devices, methods, and / or articles depending on the desired configuration. The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and / or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and sub-combinations of the disclosed features and / or combinations and sub-combinations of several further features disclosed above. In addition, the logic flows depicted in the accompanying figures and / or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations can be within the scope of the following claims.

Claims

1. A system comprising: At least one data processor; and At least one memory that stores instructions, when executed by at least one data processor, causing operations including: The fluid pressure in the fluid supply line of the infusion pump is measured by a pressure sensor. The fluid pressure includes motor pressure and patient pressure, the motor pressure being at least partially caused by the current of the motor of the infusion pump, and the patient pressure being at least partially caused by the movement of the patient. The patient pressure is determined by at least one data processor, the determination including removing motor pressure from the measured fluid pressure by a filter coupled to a pressure sensor and at least one data processor; as well as The infusion pump settings are adjusted at least in part based on a determined patient pressure. The removal further includes: The motor pressure is predicted based on the motor's current. An error signal is generated based on the comparison between the predicted motor pressure and the measured fluid pressure; and When the error value representing the error signal is less than the error threshold, the motor pressure is removed from the measured fluid pressure.

2. The system according to claim 1, wherein, The motor current is stored in the shift register of the filter.

3. The system according to claim 1, wherein, The filter is a variable digital adaptive filter.

4. The system according to claim 1, wherein, The comparison between the predicted motor pressure and the measured fluid pressure is the difference between the predicted motor pressure and the measured fluid pressure.

5. The system according to claim 1, wherein, The error value is one or more of the norm of the error signal and the least mean square of the error signal.

6. The system according to claim 1, wherein, Generating an error signal further includes applying tap filter coefficients to the error value.

7. The system according to claim 1, wherein, The removal further includes: determining whether the error value is less than an error threshold.

8. The system according to claim 7, wherein, The removal further includes: Determine that the error value is greater than or equal to the threshold; and Adjust one or more filter coefficients of the filter, which are applied to the motor current; An updated, predicted motor pressure is generated based on one or more adjusted filter coefficients and the motor current.

9. The system according to claim 8, wherein, The removal further includes: An updated error signal is generated based on a comparison between the updated predicted motor pressure and the measured fluid pressure; and It is determined that the updated error value of the updated error signal is less than the error threshold.

10. The system of claim 1, further comprising: filter; as well as Pressure sensor; At least one of the data processors includes a controller.

11. A non-volatile computer-readable storage medium comprising program code, which, when executed by at least one data processor, causes operations including: The fluid pressure in the fluid supply line of the infusion pump is measured by a pressure sensor. The fluid pressure includes motor pressure and patient pressure, the motor pressure being at least partially caused by the current of the motor of the infusion pump, and the patient pressure being at least partially caused by the movement of the patient. The patient pressure is determined by at least one data processor coupled to a pressure sensor, the determination including removing motor pressure from the measured fluid pressure by a filter coupled to the pressure sensor and at least one data processor; as well as The infusion pump settings are adjusted, at least in part, by at least one data processor based on a determined patient pressure. The removal further includes: The motor pressure is predicted based on the motor's current. An error signal is generated based on the comparison between the predicted motor pressure and the measured fluid pressure; and When the error value representing the error signal is less than the error threshold, the motor pressure is removed from the measured fluid pressure.

12. An apparatus comprising: A device for measuring fluid pressure in a fluid supply line of an infusion pump by a pressure sensor, the fluid pressure including motor pressure and patient pressure, the motor pressure being at least partially caused by current in the motor of the infusion pump, and the patient pressure being at least partially caused by movement of the patient. Device for determining patient pressure by at least one data processor coupled to a pressure sensor, the determination including removing motor pressure from the measured fluid pressure by a filter coupled to the pressure sensor and at least one data processor; as well as Device for adjusting the settings of an infusion pump based at least in part on a determined patient pressure by at least one data processor. The removal further includes: The motor pressure is predicted based on the motor's current. An error signal is generated based on the comparison between the predicted motor pressure and the measured fluid pressure; and When the error value representing the error signal is less than the error threshold, the motor pressure is removed from the measured fluid pressure.

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