ES2776363T3 - Infusion set and method using dual wavelength in-line optical air detection - Google Patents

Abstract

An infusion system for operatively connecting to a fluid supply line and an infusion container containing an infusion fluid, the infusion system comprising: at least two optical transmitters configured to transmit optical signals having different wavelengths through from the fluid supply line; wherein a first optical signal transmitted by a first optical transmitter has a first wavelength and a second optical signal transmitted by a second optical transmitter has a second wavelength different from the first wavelength, at least one optical receiver configured to receiving the first and second optical signals having the different wavelengths transmitted from the first and second optical transmitters; at least one processor in electronic communication with the at least two optical transmitters and the at least one optical receiver; and a memory in electronic communication with at least one processor, wherein the memory comprises programming code for execution by at least one processor, and the programming code is configured to determine whether there is air or infusion fluid disposed in the line based on the received first and second optical signals having the different wavelengths that are received by the at least one optical receiver, characterized in that the infusion system further comprises an optical beam splitter directing the optical signals first and second transmitted along the same optical axis through the fluid supply line.

Description

DESCRIPTION

Infusion set and method using dual wavelength in-line optical air detection

Disclosure field

This disclosure relates to an infusion set and method, which transmits and receives optical signals having different wavelengths to detect whether air is disposed in the infusion set.

Background

There are different types of infusion sets to detect if air is present in the infusion fluid. Some infusion sets currently use one or more ultrasound sensors to determine if air is present in the fluid disposed by the infusion set. However, some of these sensors are sensitive to debris, such as dirt or cleaning solution residue that is disposed of at the sensor location in the fluid supply line, which can lead to inaccurate results. Similarly, some of these sensors are sensitive to mechanical alignment or positioning, which affects their long-term accuracy and stability. Prior art infusion systems that allow air detection using optical methods are described in US 2009/097029 A1 and US 2013/201482 A1.

A system and method is needed to overcome one or more problems with one or more of the current infusion systems and methods to detect if there is air in the fluid provided by the infusion system.

Compendium

In one embodiment, an infusion system is described to be operatively connected to a fluid supply line connected to a container containing an infusion fluid. The infusion set includes at least two optical transmitters, at least one optical receiver, at least one processor, and memory. The at least two optical transmitters are configured to transmit optical signals having different wavelengths through the fluid supply line. The at least one optical receiver is configured to receive the optical signals having the different wavelengths transmitted from the at least two optical transmitters. The at least one processor is in electronic communication with the at least two optical transmitters and the at least one optical receiver. The memory is in electronic communication with at least one processor. The memory contains programming code for execution by the at least one processor. The programming code is configured to determine whether air or infusion fluid is arranged in the fluid supply line based on the received optical signals having the different wavelengths that are received by the at least one optical receiver.

In another embodiment, a method of infusing an infusion fluid is described. In one stage, the infusion fluid flows through a fluid supply line of an infusion system. In another stage, optical signals having different wavelengths are transmitted through the fluid supply line. In still another step, the transmitted optical signals having the different wavelengths are received. In yet another step, at least one processor determines whether air or infusion fluid is arranged in the fluid supply line based on the received optical signals having the different wavelengths.

In a further embodiment, an infusion system is described to be operatively connected to a fluid supply line connected to a container containing an infusion fluid. The infusion set includes an optical transmitter, at least one optical beam splitter, at least two optical beam filters, at least two optical receivers, at least one processor, and memory. The single optical transmitter is configured to transmit a wide spectrum optical signal. The at least one optical beam splitter is configured to divide the spread spectrum optical signal into two separate beams. The at least two optical filters are configured to filter the two separate beams. The at least two optical receivers are configured to receive the two separate filtered beams. The at least one processor is in electronic communication with an optical transmitter and the at least two optical receivers. The memory is in electronic communication with at least one processor. The memory contains programming code for execution by the at least one processor. The programming code is configured to determine whether air or infusion fluid is arranged in the fluid supply line based on the two separate filtered beams received that are received by the at least two optical receivers.

The scope of this disclosure is defined solely by the appended claims and is not affected by the statements contained in this compendium.

Brief description of the drawings

The disclosure can be better understood with reference to the following drawings and description. Components in the figures are not necessarily to scale, instead emphasis is placed on illustrating the principles of the disclosure.

Figure 1 illustrates a block diagram of an infusion system in one embodiment of the disclosure.

Figure 2 illustrates a side cross-sectional view of an embodiment of two optical transmitters transmitting, using alternate modulation of the transmitters, separate, sequential, alternate optical signals having different wavelengths to an optical beam splitter that directs each separate, sequential, and alternating optics along the same optical axis through a fluid supply line, to a mirror that reflects each separate, sequential, and optical signal alternates back through the fluid supply line to an optical receiver located on the same side of the fluid supply line as the two optical transmitters and the optical beam splitter.

Figure 3 illustrates a side cross-sectional view of another embodiment of two optical transmitters that transmit, using alternate modulation of the transmitters, separate, sequential and alternate optical signals having different wavelengths to an optical beam splitter that directs each separate, sequential and alternating optical signal along the same optical axis through a fluid supply line to an optical receiver located on the opposite side of the fluid supply line from the two optical transmitters and the optical beam splitter .

Figure 4 illustrates a side cross-sectional view of another embodiment of an optical transmitter that transmits a wide spectrum optical signal, using continuous transmission, through a fluid supply line to a beam splitter that splits the optical signal from spread spectrum in two beams each passing respectively through separate optical filters before being received by separate optical receivers, with the optical transmitter arranged on an opposite side of the fluid supply line than the beam splitter, the optical filters separate and separate optical receivers.

Figure 5 illustrates a side cross-sectional view of another embodiment of two optical transmitters that transmit optical signals having different wavelengths that are pulsed in a sequential and alternating order through a first mirror or beam splitter, through a fluid supply line, to a second mirror or beam splitter that splits the optical signals into separate beams that are received by separate receivers, with the two optical transmitters, and the first mirror or beam splitter located on an opposite side of the fluid supply line than the second mirror or beam splitter and separate receivers.

Figure 6 illustrates graphics of an embodiment of a first optical transmitter that is turned on and off to transmit a first optical signal of one wavelength, and a second optical transmitter is turned on and off at times opposite the first optical transmitter to transmit a second optical signal of a different wavelength.

Figure 7 is a graph illustrating spectral scan results obtained for an embodiment of a flat plastic material that was used in an infusion pump cartridge.

Figure 8 is a graph illustrating the spectral scan results obtained for another embodiment of the same plastic material that was used in the infusion pump cartridge of Figure 7, except that the plastic material was concave.

Figure 9 is a graph illustrating the spectral scan results that were obtained for yet another embodiment of a silicone membrane, which is the medium that contains the infusion fluid in the infusion system.

Figure 10 is a graph illustrating the spectral scan results that were obtained for another embodiment of a 0.9 percent sodium chloride solution delivered through a fluid supply line of an infusion system.

Figure 11 is a graph illustrating the spectral scan results that were obtained for yet another embodiment of a 20 percent Intralipid solution (fat emulsion) that was delivered through a fluid supply line from an infusion system. .

Figure 12 illustrates a flow chart for a signal acquisition method according to one embodiment of the disclosure.

Detailed description

Figure 1 illustrates a block diagram of an infusion set 100 in one embodiment of the disclosure. The infusion system 100 comprises: an infusion container 102; a fluid supply line 104; a pump device 106; a processing device 108; a memory 109; an alarm device 110 that generates an audio, visual or other sensory signal or the like for a user; an input / output device 112; at least one optical transmitter 114; at least one optical receiver 115; and a delivery device 116. The infusion set 100 may comprise an infusion set such as Plum ™, GemStar ™, Symbiq ™, or another type of infusion set.

The infusion container 102 comprises a container for delivering an infusion fluid such as IV fluid or a drug to a patient 118. The fluid supply line 104 comprises one or more tubes (and optionally in some embodiments includes a cartridge), connected between infusion container 102, pump device 106, and delivery device 116, to transport infusion fluid from infusion container 102, through pump device 106, through delivery device 116 to patient 118 The fluid supply line 104 may also be used to transport blood to the patient 118 using the supply device 116, as a result of a pumping action of the pump device 106. The pump device 106 comprises a pump for pumping infusion fluid from infusion container 102 or to pump blood to patient 118. The Pump device 106 may comprise a plunger-based pump, a peristaltic pump, or another type of pump. In other embodiments, the infusion set 100 may not contain a pump device and may use the force of gravity to deliver the infusion fluid.

The at least one optical transmitter 114 is disposed adjacent the fluid supply line 104. The at least one optical transmitter 114 is configured to transmit optical signals having different wavelengths through the fluid supply line 104. In In one embodiment, the transmitted optical signals comprise near infrared spectrum light having variable wavelengths ranging from 600 nanometers to 1,500 nanometers. In another embodiment, the transmitted optical signals comprise near infrared spectrum light having wavelengths ranging from 940 nanometers to 1,050 nanometers. In still other embodiments, the transmitted optical signals can comprise near infrared spectrum light having varying wavelengths. In one embodiment, the at least one transmitter 114 can transmit the optical signals having the different wavelengths sequentially. The at least one optical receiver 115 is disposed adjacent the fluid supply line 104 and is configured to receive the optical signals having the different wavelengths transmitted from the at least one optical transmitter 114.

In one embodiment, the wavelengths of the optical signals transmitted by the at least one transmitter 114 are chosen so that if there is air disposed in the fluid supply line 104, the air will have a substantially greater impact on one of the signals. transmitted optical signals than other transmitted optical signals. For the purposes of this disclosure, the term "substantially" is defined as greater than 10%. In another embodiment, the wavelengths of the transmitted optical signals are optimized for the particular type of infusion fluid disposed in the fluid supply line 104 to achieve maximum differentiation between the infusion fluid disposed in the fluid supply line. 104 and air disposed in fluid supply line 104. In yet another embodiment, the at least one optical transmitter 114 and the at least one optical receiver 115 are modulated to achieve a high level of immunity to the presence of ambient light. from backlight sources such as fluorescent light, light-emitting diode light, etc. and to increase the signal-to-noise ratio of the signal acquisition system.

In one embodiment, the at least one optical transmitter 114 and the at least one optical receiver 115 are disposed on opposite sides of the fluid supply line 104. In another embodiment, the at least one optical transmitter 114 and the at least one receiver Optical 115 are disposed on the same side of fluid supply line 104 and a reflective or refractive surface 117 may be disposed on the opposite side of fluid supply line 104 to reflect or refract the optical signals transmitted from at least one optical transmitter 114, via fluid supply line 104, back to the at least one optical receiver 114. In another embodiment, at least one optical beam splitter 119 may be used to split the signal (s) ) optical (s) transmitted by the at least one optical transmitter 114.

The processing device 108, comprising at least one processor, is in electronic communication with the pump device 106, the memory 109, the at least one optical transmitter 114, the at least one optical receiver 115, the input / output device 112, and alarm device 110. Memory 109 comprises programming code 111 for execution by processing device 108. Programming code 111 is configured to determine whether air or infusion fluid is arranged in the delivery line. fluid supply 104 based on received optical signals having different wavelengths that are received by the at least one optical receiver 115. In one embodiment, processing device 108 includes memory 109 and programming code 111. In another In embodiment, the processing device 108 and memory 109 may be separate components. Processing device 108 also contains or is in communication with a clock.

In one embodiment, programming code 111 is configured to determine whether air or infusion fluid is disposed in fluid supply line 104 based on how the ratio of received optical signals having the different wavelengths that are received by the at least one optical receiver 115 is compared to a threshold.

Alarm device 110 comprises an alarm, activated or generated by processing device 108, to notify the clinician (also referred to as a "user" herein) when infusion system 100 contains air. Alarm device 110 can be configured to stop pump device 106 before a significant amount of air is delivered through fluid supply line 104 and delivery device 116 to patient 118.

The input / output device 112 comprises a device, which allows a clinician to enter or receive information. The input / output device 112 allows a clinician to enter information such as: medication information regarding the infusion fluid that is delivered from the infusion container 102; infusion information regarding the infusion of the infusion fluid that is delivered from the infusion container 102; selecting settings for processing device 108 to apply by using the programming code that contains the algorithm (s); or other information that is relevant to the infusion. The input / output device 112 may allow a clinician to select and / or confirm that the processing device 108 applies a user-entered medication infusion schedule. The input / output device 112 can send additional information to the clinician. In other embodiments, any of the information entered into input / output device 112 can be pre-installed in programming code or processing device 108. In In another embodiment, the information may be remotely programmed into processing device 108 from a remote computer or input / output device 112 may be a remote and / or portable computer.

Delivery device 116 comprises a patient vascular access point device for delivering infusion fluid from infusion container 102 to patient 118, or for delivering blood to patient 118. Delivery device 116 may comprise a needle, a catheter , a cannula, or other type of delivery device. In other embodiments, the infusion system 100 of Figure 1 can be altered to vary the components, remove one or more components, or add one or more components.

Figure 2 illustrates a side cross-sectional view of one embodiment of two optical transmitters 114 that transmit optical signals having different wavelengths to an optical beam splitter 119 that directs the separate optical signals along the same optical axis through from a fluid supply line 104 to a mirror 121 that reflects the optical signals back through the fluid supply line 104 to an optical receiver 115. In this embodiment, the transmitted optical signals of different wavelengths can be pulsed in a sequential and alternating order. Throughout this disclosure, each time the term optical beam splitter or mirror is used, in other embodiments, any type of beam splitting device, reflective surface, or refractive surface may be substituted.

Figure 3 illustrates a side cross-sectional view of another embodiment of two optical transmitters 114 that transmit optical signals having different wavelengths to an optical beam splitter 119 that directs the transmitted optical signals along the same optical axis through from fluid supply line 104 to an optical receiver 115. Optical receiver 115 is located on the opposite side of fluid supply line 104 from the two optical transmitters 114 and optical beam splitter 119. In this embodiment, transmitted optical signals of different wavelengths can be pulsed in sequential and alternating order.

Figure 4 illustrates a side cross-sectional view of yet another embodiment of an optical transmitter 114 that continuously transmits a wide spectrum optical signal having a spectrum of wavelengths through fluid supply line 104 to a splitter. optical beam 119. Optical beam splitter 119 splits the optical signal into two optical beams (or two optical signals) which then respectively each pass through separate optical filters 123 before being received by separate optical receivers 115. The two filters Optics 123 are configured to filter the two separate beams so that the two separate beams have two distinctly different wavelengths from each other when they arrive at the respective receivers 115. The optical transmitter 114 is disposed on an opposite side of the power supply line. fluid 104 such as optical beamsplitter 119, optical filters 123, and optical receivers 115.

Figure 5 illustrates a side cross-sectional view of yet another embodiment of two optical transmitters 114 that transmit optical signals having different wavelengths through a first beam splitter or mirror 119, through the fluid supply line. 104 to a second beam splitter or mirror 119 that splits the beam into two beams (that is, two optical signals) that are received by separate optical receivers 115. The two optical transmitters 114 and the first beam splitter or mirror 119 are located on an opposite side of the fluid supply line 104 than the second beam splitter or mirror 119 and the separate optical receivers 115. In this embodiment, the transmitted optical signals of different wavelengths can be pulsed in sequential and alternating order.

Figure 6 illustrates graphics of an embodiment of a first optical transmitter 114a that is turned ON and OFF to transmit a first optical signal of one wavelength, and a second optical transmitter 114b is turned on and off at times opposite the first optical transmitter 114a to transmit a second optical signal of a different wavelength.

Referring again to FIG. 3, the optical transmission Ta1 of the first optical signal having a first wavelength transmitted by optical transmitter 114, through fluid supply line 104 containing fluid, and optical receiver 115 It is determined using the equation Ta1 = C (Ttube, Tfluid, Twaste). The equation illustrates that the optical transmission Ta1 of the first optical signal is a function of the optical transmission of the first optical signal through the fluid supply line tube Ttubo, through the fluid Tfluid, and through the accumulation of debris. (i.e., dirt, debris due to cleaning solution, optical noise from environmental sources, etc.) in the T-waste fluid supply tube. Similarly, the optical transmission Ta2 of the second optical signal having a different second wavelength transmitted by the optical transmitter 114, through the fluid supply line 104 containing fluid, and to the optical receiver 115 is determined using the equation Ta2 = f (Ttube, Tfluid, Twaste). The equation again illustrates that the optical transmission Ta2 of the second optical signal is a function of the optical transmission of the second optical signal through the fluid supply line tube Ttube, through the fluid Tfluid, and through the accumulation of debris in the fluid supply line tubing Twaste.

The first optical signal Su1 detected by the optical receiver 115 is a function of the first original signal SoA1 having the first wavelength transmitted by the optical transmitter 114 and the optical transmission of the first original signal SoA1 through the supply pipe. of fluid Tpipe, through the fluid Tfluid, and through the accumulation of debris in the tubing of the fluid supply line Twastes as shown in the equation Su1 = SoA1 f (Tpipe, Tfluid, Twastes). The second optical signal S2A2 detected by the optical receiver 115 is a function of the second original signal SoA2 having the second different wavelength transmitted by the optical transmitter 114 and the Optical transmission of the second original signal So ^A 2 through the fluid supply pipe T tube, through the fluid T fluid, and through the accumulation of debris in the tube T debris as shown in the equation S2 ^A 2 = So ^A 2 f (Ttube, Tfluid, Twaste). By taking a relation of S ^A 1 / ^A 2 = S1 ^A 1 / S2 ^A 2 = So ^A 1 f (Tpipe, Tfluid, Tdes Twaste) = So ^A 1 f (Tfluid) / So ^A 2 f (Tfluid) the part of the signal effected by the fluid supply line tube and the waste transmissions cancel each other since they remain the same during the optical signal reception process, and the resulting equation is a function of the original signals and fluid transmission. Furthermore, the fact that the two optical transmitters operate on the same optical axis and are modulated at a high frequency ensures measurement through the same section of the moving fluid. To illustrate this, Nyquist's theorem states that the sampling rate of the photodetector must be greater (at least twice) than the movement of the fluid to ensure that each transmitted wavelength travels through the same section of the fluid / region. air.

At a maximum flow rate of 1,000 milliliters per hour, fluid moves at a rate of 133.84 millimeters per second in a typical 1.33 millimeter ID IV tubing for a PVC tubing. A 0.48 millimeter column of fluid in a 1.33 millimeter internal diameter tube has a volume of 1 microliter. If this column of fluid is moving at a speed of 133.84 millimeters per second, the 1 microliter column of fluid completely leaves the region in approximately 0.003 seconds; therefore, it indicates a minimum sampling frequency of 666 Hertz (for example, 2 * Nyquist frequency of 333 Hertz). Alternatively, a minimum sample rate of 666 Hertz is required to sample a 1 microliter column of fluid in a 1.33 millimeter ID IV tube. Light Emitting Diodes (LEDs) can be modulated in the megahertz region and can adequately sample and accommodate virtually any flow rate used in infusion therapies.

A simplified version of the equation when the fluid in fluid supply line 104 is fluid comprises

S ^A 1 / ^A 2_fluid = S1 ^A 1 / S2 ^A 2 = So ^A 1 f (Tfluid) / So ^A 2 f (Tfluid) = Fluid. A simplified version of the equation when air is arranged in the fluid supply line 104 comprises S ^A 1 / ^A 2_air = S1 ^A 1 / S2 ^A 2 = So ^A 1 f (Taire) / So ^A 2 f (Taire) = Air. The simplified equations illustrate that the relationships give different distinct values with Fluid indicating that the fluid is disposed in the fluid supply line 104 and with Aair indicating that the air is disposed in the fluid supply line 104. As a result, these equations / Relationships can be used to detect when there is air in the fluid supply line 104. The equations / relationships can give variable results for different liquids that are arranged in the fluid supply line 104 but are easily distinguishable from the results of the equations when air is available and present in fluid supply line 104.

Beer-Lambert's Law (or Beer's Law) together with the proposed ratiometric method supports this disclosure.

Beer's Law relates the absorption of light to the properties of the material through which the light travels. Beer's Law states that there is an exponential dependence between the transmission of light through a substance and the product of the absorption coefficient (that is, in this case tubes, fluid / air, dirt, residues due to cleaning solutions, etc.) of the substance and the distance the light travels through the substance (i.e. the axis

T = - = e aL,

optical). In particular, Beer's Law states that io where T is transmission, I is intensity, is the initial intensity, a is the absorption coefficient and L is the optical path length. The absorption coefficient is made up of the absorption coefficients of the pipe, fluid / air / foam, and any residue due to cleaning solutions or oil and dirt. More specifically, the equation can be rewritten for the intensities that the optical receiver will "observe" from the two different optical wavelengths, namely li = loe-aiL and I2 = loe-a2L, because L is a constant and as a result from the close separation of the different wavelengths, ai = a2. Taking the ratio of li and I2 cancels out the common elements such as residues due to cleaning solution or oil and dirt, and the tube material parameters leave the equation to contain only the ratio of the initial intensities (which are know). Since the transmitted wavelengths share the same optical path, tubes, debris ("noise"), and sample the same section of the fluid column, the only significant difference is whether the sampled region contains air or air; thus offering immunity to noise and resulting in a high signal-to-noise ratio. A similar approach is valid for all the embodiments described in this disclosure, including the use of at least one transmitter and at least one receiver. The disclosure does not convey a limit on the number of transmitters or receivers that can be used in alternative embodiments.

Because this disclosure provides immunity against ambient noise (dirt, ambient light, cleaning solution residue, etc.) there is the advantage of self-calibration of the optical sensor. One method of using autocalibration in an infusion pump is to provide a baseline reading without the presence of the IV tube (and cartridge) and before loading the IV tube (and cartridge) into the infuser. Because this disclosure is not an amplitude-based optical sensor system, but rather a ratiometric method, the initial reference reading (without the presence of the IV tube and / or cartridge) provides a reference reading. The current state of the art of air sensors in the typical infusion pump is based on ultrasound technology that does not provide the opportunity to self-calibrate the ultrasound sensor nor does it provide immunity to mechanical changes or external noise factors (dirt, etc. .). Routine calibration is generally required for these state-of-the-art air sensors in infusion pumps as part of overall life cycle management. This disclosure does not require calibration in the field or at the service facility as the device automatically calibrates itself before each use.

Figure 7 is a graph illustrating the spectral scan results that were obtained for a flat plastic material that was used in an infusion pump cartridge comprising part of a fluid supply line 104. The wavelength is plotted in the X-axis and the percent transmittance is plotted on the Y-axis. The graph shows that from about 400 nanometers to about 1,600 nanometers, the transmittance is above 70 percent with a slight drop by about 1,600 nanometers, and returns to about 70 percent before indicating no transmittance as the wavelength continues to increase with the scan ending at about 4,000 nanometers. The transmittance is greater than 70 percent in the range of 1,000 nanometers to 1,500 nanometers. Figure 7 demonstrates that varying the wavelengths of the optical signals results in substantial changes in transmittance.

Figure 8 is a graph illustrating the spectral scan results that were obtained for the same plastic material that was used in the infusion pump cartridge of Figure 7, with the exception that the plastic material was concave. Wavelength is plotted on the X axis and percent transmittance is plotted on the Y axis. The graph shows that transmittance is greater than 80 percent in the range of 1,000 nanometers to 1,500 nanometers. Figure 8 demonstrates that varying the wavelengths of the optical signals results in substantial changes in transmittance.

Figure 9 is a graph illustrating the spectral scan results that were obtained for a silicone membrane material that was used in an infusion pump cartridge. The wavelength is plotted on the X axis and the percent transmittance is plotted on the Y axis. The graph shows that the transmittance is greater than 40 percent in the range of 1,000 nanometers to 1,500 nanometers. Figure 9 demonstrates that varying the wavelengths of the optical signals results in substantial changes in transmittance.

Figure 10 is a graph illustrating the spectral scan results that were obtained for a 0.9 percent sodium chloride solution that was delivered through a fluid supply line of an infusion system. Wavelength is plotted on the X-axis and percent transmittance is plotted on the Y-axis. The graph shows that transmittance is greater than 90 percent in the range of 400 nanometers to 1,800 nanometers. The length of the optical axis was 1 mm. Figure 10 demonstrates that varying the wavelengths of the optical signals results in substantial changes in transmittance.

Figure 11 is a graph illustrating the spectral scan results that were obtained for a 20 percent Intralipid solution (fat emulsion) used in a fluid supply line of an infusion system. Wavelength is plotted on the X axis and percent transmittance is plotted on the Y axis. The graph shows that transmittance is lowest in the range of 400 nanometers to about 1,200 nanometers and then increases with wavelength up to end of scan at approximately 1,800 nanometers. The length of the optical axis was 1 nanometer. Figure 11 demonstrates that varying the wavelengths of optical signals results in substantial changes in transmittance.

Figure 12 illustrates a flow chart of one embodiment of a method 120 for infusing an infusion fluid. The method 120 can use the infusion system 100 of FIG. 1. In other embodiments, the method 120 can use variable systems including, but not limited to, any system described herein. In step 122, the infusion fluid flows through a fluid supply line of an infusion system. In step 124, optical signals having different wavelengths are transmitted through the fluid supply line. In one embodiment, the different wavelengths of the optical signals were optimized for the particular type of infusion fluid arranged in the fluid supply line to achieve maximum differentiation between the infusion fluid arranged in the fluid supply line and the air disposed in the fluid supply line.

In one embodiment, the optical signals comprise near infrared spectrum light having variable wavelengths ranging from 600 nanometers to 1,500 nanometers. In another embodiment, the transmitted optical signals comprise near infrared spectrum light having variable wavelengths ranging from 940 nanometers to 1,050 nanometers. In other embodiments, the transmitted optical signals can comprise light having varying wavelengths. In another embodiment, the at least one optical transmitter that transmits the optical signals can be modulated to achieve a high level of immunity to the presence of ambient light from background light sources such as fluorescent light, light emitting diode light, etc. . and to increase the signal-to-noise ratio of the signal acquisition system. In step 126, the transmitted optical signals having the different wavelengths are received.

In step 128, at least one processor determines whether air or infusion fluid is arranged in the fluid supply line based on the received optical signals having the different wavelengths. In one embodiment, step 128 comprises the at least one processor that determines whether air or infusion fluid is arranged in the fluid supply line based on how a ratio of the received optical signals having the different wavelengths is compares with a threshold. In one embodiment, step 128 comprises the at least one processor that determines the transmittance property of the infusion fluid or air between two spectral regions. In step 130, if the determination is made in step 128 that there is air in the infusion system, the at least one processor 108 generates an alarm and the alarm device 110 generates the appropriate sound or visual exposure to notify the user. In one embodiment, step 130 may comprise at least one processor turning off a pump of the infusion set if the alarm sounds.

In one embodiment, steps 124, 126, and 128 comprise: in step 124, transmitting a first optical signal that has a first wavelength and transmitting a second optical signal that has a second wavelength different from the first wavelength. through the fluid supply line; in step 126, receiving the first optical signal and the second optical signal; and in step 128, determining with the at least one processor whether the air or infusion fluid is arranged in the fluid supply line based on the received optical signals having the different wavelengths with the at least one processor that finds that the air disposed in the fluid supply line has a substantially greater impact on the first received optical signal than on the second received optical signal.

In one embodiment, steps 124 and 126 comprise: at step 124, two optical transmitters that transmit the optical signals having the different wavelengths through the fluid supply line; and in step 126, only one optical receiver that receives the transmitted optical signals having the different wavelengths.

In one embodiment, steps 124 and 126 comprise: at step 124, two optical transmitters that transmit the optical signals having the different wavelengths through the fluid supply line; and in step 126, two optical receivers that receive the transmitted optical signals having the different wavelengths.

In one embodiment, steps 124 and 126 may utilize at least one optical transmitter and at least one optical receiver disposed on opposite sides of the fluid supply line. In another embodiment, steps 124 and 126 may use at least one optical transmitter and at least one optical receiver arranged on the same side of the fluid supply line, and a reflective or refractive surface arranged on the opposite side of the fluid supply line. fluid supply for reflecting or refracting the optical signals transmitted from the at least one optical transmitter, through the fluid supply line, back to the at least one optical receiver.

In other embodiments, any number, configuration, orientation, or location of optical transmitters and optical receivers can be used. In still other embodiments, an optical beam splitter can be used to direct the optical signals to travel along a common optical axis. In further embodiments, a reflective or refractive surface can be used to reflect or refract the optical signals having the different wavelengths to the at least one optical receiver. In other embodiments, additional components can be used in combination with at least one optical transmitter and at least one optical receiver to help transmit or receive the optical signals. In other embodiments, method 120 can be altered to vary the order or substance of any of the steps, to remove one or more steps, or to add one or more steps.

The applicant has conducted tests using various infusion fluids (including 0.9 percent sodium chloride, 50 percent dextrose, 20 percent Intralipid, and 4.7 percent egg white) and various flow rates (including 250 milliliters per hour; 500 milliliters per hour; and 1,000 milliliters per hour) to compare the results of using the optical system and the disclosure method to determine if air is available in the fluid supply line of an infusion system versus Use an ultrasound sensor system (piezoelectric crystal receiver-transmitter pair interconnected with a voltage scanning electronic oscillator sweeping through the sensor's maximum coupling frequency) to make this determination. The tests have revealed that the optical system and the method of the disclosure have unexpected substantial results on the use of the ultrasound sensor. The use of the optical system and the disclosure method resulted in an improvement in resolution, defined as the smallest bubble size that the sensor can detect, for all infusion fluids tested at each of the various flow rates up to 72 percent improvement over the use of the ultrasound sensor. The use of the optical system and the disclosure method resulted in an improvement in accuracy, defined as the speed of detection, for all infusion fluids tested at each of the various flow rates in a range of 6 to 72 percent of improvement over the use of the ultrasound sensor. The use of the optical system and the method of the disclosure resulted in an improvement in signal-to-noise calculation for all infusion fluids tested at each of the various flow rates in a range of 280 to 800 percent improvement over the use of the ultrasound sensor. The use of the optical system and the method of the disclosure resulted in an improvement in dynamic range, defined as the difference between the largest and smallest bubble that the sensor could detect, for all infusion fluids tested in each. of the various flow rates up to a 10.7 percent improvement over the use of the ultrasound sensor.

The compendium is provided to enable the reader to quickly determine the nature of the technical disclosure. It is presented with the understanding that it is not to be used to interpret or limit the scope or meaning of the claims. Furthermore, from the detailed description above, it can be seen that in various embodiments, various features are grouped together in order to streamline the disclosure. This method of disclosure should not be construed as reflecting the intention that the claimed embodiments require more features than are expressly mentioned in each claim.

While particular aspects of the present subject matter described herein have been shown and described, it will be apparent to those skilled in the art that, based on the teachings of this document, changes and modifications can be made without departing from the scope of the appended claims.

Claims (14)

1. An infusion system for operatively connected to a fluid supply line and an infusion container containing an infusion fluid, the infusion system comprising: at least two optical transmitters configured to transmit optical signals having different wavelengths through the fluid supply line; wherein a first optical signal transmitted by a first optical transmitter has a first wavelength and a second optical signal transmitted by a second optical transmitter has a second wavelength different from the first wavelength, at least one optical receiver configured to receive the first and second optical signals having the different wavelengths transmitted from the first and second optical transmitters; at least one processor in electronic communication with the at least two optical transmitters and the at least one optical receiver; and a memory in electronic communication with at least one processor, wherein the memory comprises a programming code for execution by at least one processor, and the programming code is configured to determine if there is air or infusion fluid disposed in the fluid supply line based on the first and second optical signals received that have the different wavelengths that are received by the at least one optical receiver, characterized by what The infusion system further comprises an optical beam splitter that directs the first and second optical signals transmitted along the same optical axis through the fluid supply line. 2. The infusion system of claim 1 wherein the programming code is configured to determine whether air or infusion fluid is arranged in the fluid supply line based on how a ratio of the received optical signals having the different wavelengths, which are received by at least one optical receiver, are compared with a threshold. 3. The infusion set of claim 1 wherein the optical signals comprise near infrared spectrum light. The infusion system of claim 1 wherein if air is disposed in the fluid supply line, the air will have a substantially greater impact on the first optical signal received by the at least one optical receiver than on the second signal. optical received by the at least one optical receiver. The infusion system of claim 1 wherein the wavelengths of the optical signals are optimized for the particular type of infusion fluid disposed in the fluid supply line to achieve maximum differentiation between the air disposed in the line. supply fluid and infusion fluid disposed in the fluid delivery line. 6. The infusion system of claim 1 wherein the at least two optical transmitters are configured to transmit the optical signals alternately and sequentially. 7. A method of infusing an infusion fluid comprising: flowing infusion fluid through a fluid supply line of an infusion system; transmitting a first optical signal having a first wavelength and transmitting a second optical signal having a second wavelength different from the first wavelength through a fluid supply line; directing the first and second optical signals along the same optical axis through the fluid supply line with an optical beam splitter, receiving the first optical signal and the second optical signal; and determining, with at least one processor, whether there is air or infusion fluid disposed in the fluid supply line based on the received first and second optical signals having the different wavelengths. The method of claim 7, wherein the at least one processor determines whether air or infusion fluid is arranged in the fluid supply line based on how a ratio of the received optical signals having the different lengths of wave is compared to a threshold. The method of claim 7 wherein the optical signals comprise near infrared spectrum light. The method of claim 7, wherein determining with the at least one processor whether the air or infusion fluid is arranged in the fluid supply line based on the received optical signals having the different wavelengths comprise the at least one processor that determines that the air disposed in the fluid supply line has a substantially greater impact on the first received optical signal than on the second received optical signal. The method of claim 7, further comprising optimizing the wavelengths of the optical signals for the particular type of infusion fluid disposed in the fluid supply line to achieve maximum differentiation between the air disposed in the supply line. fluid supply and infusion fluid arranged in the fluid supply line. The method of claim 7, wherein the transmission of the optical signals having different wavelengths through the fluid supply line comprises at least two optical transmitters that alternately and sequentially transmit the optical signals having the different wavelengths through the fluid supply line along the same optical beam axis using at least one optical beam splitter, at least one mirror, at least one reflective surface, or at least one refractive surface. 13. The infusion system of claim 1, comprising: an optical transmitter configured to transmit a spread spectrum optical signal; at least one optical beam splitter configured to split the spread spectrum optical signal into two separate beams; at least two optical filters configured to filter the two separate beams so that the two separate beams have two distinctly different wavelengths from each other; at least two optical receivers configured to receive the two separate filtered beams having the two distinctly different wavelengths; at least one processor in electronic communication with an optical transmitter and the at least two optical receivers; and a memory in electronic communication with the at least one processor, wherein the memory comprises a programming code for execution by the at least one processor, and the programming code is configured to determine whether there is air or infusion fluid arranged in the fluid supply line based on the two received filtered separate beams having the two distinctly different wavelengths that are received by at least two optical receivers. The infusion system of claim 13, wherein the single optical transmitter is configured to transmit the optical signal continuously, and the programming code is configured to determine whether air or infusion fluid is arranged in the fluid supply line based on how the two separate filtered beams received by the at least two optical receivers are compared to a threshold.