Patent Description:
For a more complete understanding of various examples, reference is now made to the following description taken in connection with the accompanying drawings in which:.

As noted above, microfluidic devices may be provided to flow fluids through narrow channels to, for example, reaction chambers. The fluids may include any number of particles within a flow. A reaction chamber or another output of the channels may use the particles in a separated or concentrated condition. Accordingly, the various particles in a flow are separated (e.g., sorted or categorized) for use within the microfluidic device or for output from the microfluidic device.

In order to separate the particles, some devices use a valve to open a corresponding channel to direct a particle into an appropriate channel. Such valves typically result in slowing of the flow upstream of the valve. Further, such valves have the potential to fail, resulting in failure of sorting in all output channels.

Further, categorizing or flow of particles may be facilitated with the use of pumps. While any of a variety of pumps may be used, external pumps (e.g., syringe pumps or capillary pumps) may increase complexity and expense by requiring a pump to be outside the lab-on-a-chip, for example.

The present invention is defined in and by the appended claims, which relate to categorizing and/or sorting of particles in, for example, a microfluidic device. A flow of particles containing at least two categories of particles is sorted by directing each particle from an input channel to one of at least two output channels, each output channel corresponding to a different category. A sensor in the input channel can detect a particle, which may be identified as belonging to a particular category, either by the sensor itself or another processor or controller. Each output channel is provided with a pump, such as an inertial pump. Activation of the pump in a particular output channel causes flow in that channel to be slowed, stopped, or reversed. Thus, flow from the input channel is directed away from the output channel with the activated pump. Based on the detection of the particle by the sensor in the input channel, the pump in each output channel not corresponding to the category of the detected particle, or corresponding to a category that is different than the category of the detected particle, is activated. Thus, flow is slowed, stopped, or reversed in output channels corresponding to a different category than the category of the detected particle, and the detected particle is directed into the output channel corresponding to its category. Further, in various examples, each pump may be an inertial pump that is integrated within the device, such as within a corresponding channel,.

Referring now to the Figures, <FIG> illustrates a system, not claimed, for categorizing, or sorting, of particles. The system may be any of a variety of devices, such as microfluidic devices, lab-on-a-chip, or micro total analytical systems, for example. Accordingly, while the system <NUM> may be described in the microfluidic context, in other examples, the system <NUM> may include a system for categorizing larger particles than those found in the microfluidic environment. In the system of <FIG>, the system <NUM> includes an input channel <NUM> with a first end <NUM> and a second end <NUM>. The input channel <NUM> may receive particles therein through the first end <NUM>. An arrow in the input channel <NUM> illustrated in <FIG> indicates the direction of flow of the particles. As noted above, the particles may include any of a variety of particles such as, but not limited to, blood cells. The input channel <NUM> may be a long and/or narrow channel.

System <NUM> may be a microfluidic device, and the input channel <NUM> may be a microfluidic channel. The input channel <NUM> may have a cross-sectional width of between about <NUM> and about <NUM>. Various examples of the system <NUM> may be formed by performing various microfabrication and/or micromachining processes on a substrate to form and/or connect structures and/or components. The substrate may comprise a silicon based wafer or other such similar materials used for microfabricated devices (e.g., glass, gallium arsenide, plastics, etc.) and may comprise microfluidic channels, fluid actuators, and/or volumetric chambers. Microfluidic channels and/or chambers may be formed by performing etching, microfabrication processes (e.g., photolithography), or micromachining processes in a substrate. Accordingly, microfluidic channels and/or chambers may be defined by surfaces fabricated in the substrate of a microfluidic device. In some implementations, microfluidic channels and/or chambers may be formed by an overall package, wherein multiple connected package components that combine to form or define the microfluidic channel and/or chamber.

In <FIG>, the system <NUM> includes a sensor <NUM>. The sensor <NUM> may be selected from any of a variety of types of sensors. Sensor <NUM> may include, but not limited to, an electrical current sensor, an impedance sensor, an optical sensor, magnetic, imaging, or a thermal sensor. The sensor <NUM> is provided to categorize particles in the input channel <NUM> into one of at least two categories. For example, a stream of particles flowing through the input channel <NUM> may include two, three, or more different categories of particles. The categories of particles may include, but not limited to, solid particles, soft particles, gas bubbles, biological cells, droplets of fluid (e.g., immiscible fluid, also referred to as colloidal particles), and clusters thereof. A category may include a particular type of particle or a group of types of particles. A category may include all blood cells, and in another example, a category may include a particular type of blood cell. The sensor may be positioned to allow detection of a particle and identification of at least one parameter associated with the particle which allows categorization of the particle.

The system <NUM> further includes at least two output channels 130a, 130b that are coupled to the second end <NUM> of the input channel <NUM> to receive particles from the input channel <NUM>. In <FIG>, a flow of particles in the input channel <NUM> forks into one of the two output channels 130a, 130b. The arrows in the output channels 130a, 130b in <FIG> indicate the direction of flow of the particles in the output channels 130a, 130b. The input channel <NUM> may be coupled to any practical number of output channels <NUM>, such as three, four, or more output channels. Each output channel 130a, 130b is associated with at least one category of the at least two categories. The flow of particles through the input channel <NUM> includes particles belonging to category A and category B. In <FIG>, one output channel 130a is associated with category A, and the outer output channel 130b is associated with category B.

In the system <NUM> of <FIG>, each output channel 130a, 130b is provided with a corresponding pump 140a, 140b. In the scenario in which the example system <NUM> is a microfluidic device, each pump 140a, 140b may be an inertial pump. As used herein, an inertial pump corresponds to a fluid actuator and related components disposed in an asymmetric position in a microfluidic channel, where an asymmetric position of the fluid actuator corresponds to the fluid actuator being positioned less distance from a first end of a microfluidic channel as compared to a distance to a second end of the microfluidic channel. Accordingly, in some examples, a fluid actuator of an inertial pump may not be positioned at a mid-point of a microfluidic channel. The asymmetric positioning of the fluid actuator in the microfluidic channel facilitates an asymmetric response in fluid proximate the fluid actuator that results in fluid displacement when the fluid actuator is actuated. Repeated actuation of the fluid actuator causes a pulse-like flow of fluid through the microfluidic channel.

In some examples, an inertial pump includes a thermal actuator having a heating element (e.g., a thermal resistor) that may be heated to cause a bubble to form in a fluid proximate the heating element. In such examples, a surface of a heating element (having a surface area) may be proximate to a surface of a microfluidic channel in which the heating element is disposed such that fluid in the microfluidic channel may thermally interact with the heating element. In some examples, the heating element may comprise a thermal resistor with at least one passivation layer disposed on a heating surface such that fluid to be heated may contact a topmost surface of the at least one passivation layer. Formation and subsequent collapse of such bubble may generate circulation flow of the fluid. As will be appreciated, asymmetries of the expansion-collapse cycle for a bubble may generate such flow for fluid pumping, where such pumping may be referred to as "inertial pumping. " In other examples, a fluid actuator corresponding to an inertial pump may comprise a membrane (such as a piezo-electric membrane) that may generate compressive and tensile fluid displacements to thereby cause fluid flow.

Of course, in other examples, any of a variety of other types of pumps may be used. Each pump 140a, 140b is operable, based on the categorization of a detected particle (e.g., by the sensor <NUM>), to selectively slow, stop, or reverse flow of particles into the output channel 130a, 130b from the input channel <NUM>. In this regard, the pump 140a, 140b may pump a fluid in a direction opposite the direction of the flow of particles from the input channel <NUM>. The rate of pumping of the fluid by the pump 140a, 140b may be sufficient to slow, stop, or reverse the flow from the input channel <NUM>.

The input channel <NUM> and each output channel 130a, 130b may be microfluidic channels. In this regard, the input channel <NUM> and the output channels 130a, 130b may have a cross-sectional width of between about <NUM> and about <NUM>, for example.

Referring now to <FIG>, a categorizing of particles using the system <NUM> of <FIG> is illustrated. Referring first to <FIG>, a flow of particles <NUM> is illustrated flowing through the input channel <NUM>. The term "particles" is used herein to refer to any of a variety of objects including, but not limited to, solid particles, soft particles, gas bubbles, biological cells, droplets of fluid (e.g., immiscible fluid, also referred to as colloidal particles, or their agglomerates), and clusters thereof. As noted above, the direction of the flow is indicated by the arrow, as left to right in <FIG>. The flow of particles <NUM> includes particles belonging to at least two categories. In the example illustrated in <FIG>, the flow includes particles in two categories, category A and category B. The particles belonging to category A are illustrated as open circles <NUM>, and the particles belonging to category B are illustrated as closed circles <NUM>. The system <NUM> may operate to provide a concentration of one particle. In this regard, the desired particle may be indicated as category A and may be directed to a reservoir to hold the particle in a concentrated form. Category B may indicate all other particles in the flow <NUM>, which may be considered waste, and may be directed to a waste chamber.

Referring now to <FIG>, a particle <NUM> reaches a point in the input channel <NUM> where it is detected by the sensor <NUM>. The sensor <NUM> may detect not only the presence of the particle <NUM> in a detection zone, for example, of the input channel <NUM>, but may also detect a characteristic of the particle which allows categorization of the particle <NUM> into one of the set of categories (e.g., category A or category B). Such characteristics may include any of a variety of parameters, such as size, shape, dielectric constant, electric polarizability, magnetic susceptibility, magnetic moment, optical refractive index, color, luminescence, thermal capacitance, and thermal conductivity, for example. The sensor <NUM> itself may categorize the particle <NUM> based on the detected characteristic, or the sensor <NUM> may provide a signal to a controller indicating the detected characteristic for the controller to perform the categorization. In <FIG>, the detected particle <NUM> is characterized as belonging to category A.

Referring now to <FIG>, based on the categorization of the particle <NUM> in category A, pumps corresponding to all output channels that are not associated with category A are actuated. In other words, pumps corresponding to all output channels that are associated with a different category than the identified category of the particle <NUM> are actuated. In <FIG>, output channel 130a is associated with category A, and output channel 130b is associated with category B. Accordingly, the pump 140b corresponding to output channel 130b is actuated, as illustrated by the bold outline of pump 140b in <FIG>. The actuation of the pump 140b causes the flow into output channel 130b to slow, stop, or reverse, as indicated by the removal of the arrow corresponding to the output channel 130b in <FIG>.

The flow of the particles <NUM> may include a fluid which carries the particles <NUM> through the channel. The fluid may be a gas or a liquid, for example. The particles may be solid or liquid particles, and the pumps 140a, 140b may be inertial pumps. The actuation of the pump may cause the pump to force a similar or identical fluid in a direction opposite the flow from the input channel <NUM>. This flow caused by the pump 140b serves to stop, slow, or reverse the flow from the input channel <NUM>. As illustrated in <FIG>, this causes the particle <NUM> to flow into the output channel 130a corresponding to the category (category A) associated with the particle <NUM>.

Referring now to <FIG>, the flow of particles <NUM> in the input channel <NUM> continues with another particle being detected by the sensor <NUM>. In <FIG>, the next particle <NUM> belongs to category B (as indicated by the closed circle). Based on the categorization of the particle <NUM> in category B, pumps corresponding to all output channels that are associated with a category that is different from category B are actuated. As illustrated in <FIG>, the pump 140a corresponding to output channel 130a, which is associated with category A, is actuated, as illustrated by the bold outline of pump 140a in <FIG>. The actuation of the pump 140a causes the flow into output channel 130a to slow, stop, or reverse, as indicated by the removal of the arrow corresponding to the output channel 130a in <FIG>. The particle <NUM> is thus directed into the appropriate output channel 130b corresponding the categorization of the particle <NUM> into category B.

As noted above, the pumps corresponding to all output channels that are associated with a category that is different from the identified category are actuated to slow, stop, or reverse flow in those channels. With reference to <FIG>, the pump 140a may be actuated to slow flow into the output channel 130a that corresponds to a different category (category A) than the identified category B of the incoming particle <NUM>. The slower flow rate in the output channel 130a may cause the particle <NUM> already in the output channel 130a to continue flowing, but the slower flow rate in the output channel 130a causes the incoming particle <NUM> to flow into the output channel 130b associated with the identified category B.

Similarly, if the pump 140a is actuated to stop flow into the output channel 130a that corresponds to a category that is different from category B, the particle <NUM> already in the output channel 130a may stop flowing and hold its position within the output channel 130a. The stopped flow in the output channel 130a causes the incoming particle <NUM> to flow into the output channel 130b associated with the identified category B of the incoming particle <NUM> since the flow into the output channel 130b continues to flow.

Finally, if the pump is actuated to reverse the flow in the output channel 130a that corresponds to a category that is different from category B, the particle <NUM> already in the output channel 130a may reverse direction and flow toward the entrance to the output channel 130a. An additional sensor may be provided proximate to the entrance of the output channel 130a (e.g., at the intersection of the output channel 130a and the input channel <NUM>) to prevent the particle <NUM> from going into the input channel <NUM> or a different output channel (e.g., output channel 130b). The reversed flow in the output channel 130a causes the incoming particle <NUM> to flow into the output channel 130b associated with the identified category B since the flow into the output channel 130b continues to flow in the forward direction, as indicated by the arrow in <FIG>.

This categorizing process may then continue for subsequent particles <NUM> in the input channel <NUM>. As the particles are sorted into the output channels 130a, 130b corresponding to the categorization of each particle, the particles <NUM> may be directed into, for example, reservoirs, reaction chambers, or further sorting channels.

In the system <NUM> of <FIG>, the output channels 130a, 130b are shown coupled to the input channel <NUM> in a perpendicular orientation. It will be understood that this manner of coupling is illustrated for schematic purposes and the output channels 130a, 130b may be coupled to the input channel <NUM> in any feasible orientation. <FIG> illustrates a system <NUM>, which is not within the scope of the claims, in which the output channels 730a, 730b fork from an input channel <NUM> to form a Y-shape intersection. Of course, a variety of other arrangements is possible and is contemplated within the scope of the present disclosure.

Further, in system <NUM> of <FIG>, the input channel <NUM> is coupled to two output channels 130a, 130b. A system may include a larger number of output channels forming a two-dimensional intersection or a three-dimensional intersection. <FIG> illustrates a system <NUM>, which is not within the scope of the claims, in which an input channel <NUM> is coupled to five output channels 830a-e. Of course, any practical number of output channels 830a-e coupled to the input channel <NUM> is possible and is contemplated within the scope of the present disclosure.

Referring now to <FIG>, another system, which is not within the scope of the claims, for categorizing of particles is illustrated. The system <NUM> of <FIG> is similar to the system <NUM> described above with reference to <FIG> and includes an input channel <NUM>, a sensor <NUM> and output channels 930a, 930b. Similar to the system <NUM> described above, the system <NUM> of <FIG> is provided with pumps 940a, 940b associated with each output channel 930a, 930b.

The system <NUM> of <FIG> is further provided with a controller <NUM>. The controller <NUM> is coupled to the sensor <NUM> and to each pump 940a, 940b in the output channels 930a, 930b. The controller <NUM> may receive signals from the sensor <NUM>, such as signals to indicate detection of a particle in the input channel <NUM>. The signals from the sensor <NUM> may be indicative of categorization of the particle in a selected category of the at least two categories (e.g., category A or category B). The signal received by the controller <NUM> from the sensor <NUM> may provide the category of the detected particle. The signal may provide a characteristic of the detected particle, enabling the controller <NUM> to determine the appropriate category of the particle.

As noted above, the controller <NUM> of the system <NUM> is coupled to each pump 940a, 940b corresponding to each output channel 930a, 930b. Based on the categorization of the particle detected by the sensor <NUM>, the controller <NUM> may send signals to the appropriate pump(s) 940a, 940b to facilitate categorizing or sorting of the detected particle. As described above with reference to <FIG>, the controller <NUM> may actuate the pump corresponding to each output channel 930a, 930b that is associated with a category that is different from the category of the detected particle.

Referring now to <FIG>, another example system for categorizing of particles, which is not within the scope of the claims, is illustrated. The system <NUM> of <FIG> is similar to the system <NUM> described above with reference to <FIG> and includes an input channel <NUM>, a sensor <NUM> and output channels 1030a, 1030b. Similar to the system <NUM> described above, the system <NUM> of <FIG> is provided with pumps 1040a, 1040b associated with each output channel 1030a, 1030b.

In the system <NUM> of <FIG>, the flow of particles in the input channel <NUM> is received from a sample source <NUM>. The sample source <NUM> may be, for example, a reservoir or a reaction chamber which outputs the flow of particles <NUM>. The flow of particles <NUM> from the sample source <NUM> may contain a density or concentration of particles that may be greater than desired for the categorizing process. In this regard, the system <NUM> of <FIG> is provided with a dilutant <NUM> which is directed to combine with the flow of particles <NUM> from the sample source <NUM>. The dilutant <NUM> may be similar or identical to the fluid carrying the particles <NUM> from the sample source <NUM>.

The combining of the dilutant <NUM> with the flow of particles <NUM> from the sample source results in a diluted flow of particles <NUM> through the input channel <NUM>. In <FIG>, the diluted flow of particles <NUM> is illustrated with increased spacing between the particles. The diluted flow of particles <NUM> can then be sorted as described above with reference to <FIG>.

As illustrated in <FIG>, pumps may be provided to control the flow of the sample and the dilutant into the input channel <NUM>. In <FIG>, a pump <NUM> is provided to control the rate of flow of the sample <NUM>, and a pump <NUM> is provided to control the rate of flow of the dilutant <NUM>. In this regard, the ratio of sample to dilutant, or the dilution of the sample <NUM>, can be controlled. The pumps 1040a, 1040b in the output channels 1030a, 1030b may facilitate categorizing or sorting of particles, as described above.

Referring now to <FIG>, an example system for categorizing of particles is illustrated. The example system <NUM> of <FIG> is similar to the example system <NUM> described above with reference to <FIG> and includes an input channel <NUM>, a sensor <NUM> and output channels 1130a, 1130b. Similar to the example system <NUM> described above, the example system <NUM> of <FIG> is provided with pumps 1140a, 1140b associated with each output channel 1130a, 1130b.

As noted above, in some examples, a category of particles may include a group of types of particles, such as all types of blood cells. In such cases, it may be desirable to further sort the category of particles into at least two subcategories. In this regard, the example system <NUM> of <FIG> includes an output channel sensor <NUM> positioned to detect particles in the output channel 1130a. The output channel sensor <NUM> may be provided to categorize particles flowing through the output channel 1130a into one of at least two sub-categories. The example system <NUM> further includes at least two sub-output channels 1160a, 1160b that are coupled to the output channel 1130a. Thus, the sub-output channels 1160a, 1160b are to receive particles from the output channel 1130a. Each sub-output channel 1160a, 1160b is associated with a sub-category. In the example of <FIG>, the sub-output channel 1160a is associated with sub-category A<NUM>, and the sub-output channel 1160b is associated with sub-category A<NUM>.

In the example system <NUM> of <FIG>, each sub-output channel 1160a, 1160b is provided with a corresponding pump 1170a, 1170b. The pumps 1170a, 1170b are operable to selectively slow, stop, or reverse flow of particles into the corresponding sub-output channel 1160a, 1160b from the output channel 1130a. Each pump 1170a, 1170b is operable, based on the categorization of a detected particle (e.g., by the output channel sensor <NUM>), to selectively slow, stop, or reverse flow of particles into the sub-output channel 1160a, 1160b from the output channel 1130a. As noted above, actuation of the pumps 1170a, 1170b may be based on categorization of a particle in the output channel 1130a. In the example of <FIG>, the sub-output channel 1160a is associated with category A<NUM>, and sub-output channel 1160b is associated with category A<NUM>. Thus, if a particle detected by the output channel sensor <NUM> is categorized as category A<NUM>, pumps corresponding to all sub-output channels that are associated with a category that is different from category A<NUM> are actuated. Accordingly, the pump 1170b corresponding to sub-output channel 1160b is actuated. Similarly, if a particle detected by the output channel sensor <NUM> is categorized as category A<NUM>, pumps corresponding to all sub-output channels that are associated with a category that is different from category A<NUM> are actuated. Accordingly, the pump 1170a corresponding to sub-output channel 1160a is actuated.

Referring now to <FIG>, another example system for categorizing of particles is illustrated. The example system <NUM> of <FIG> is similar to the example system <NUM> described above with reference to <FIG> and includes an input channel <NUM>, a sensor <NUM> and output channels 1230a, 1230b. Similar to the example system <NUM> described above, the example system <NUM> of <FIG> is provided with pumps 1240a, 1240b associated with each output channel 1230a, 1230b.

In the example system <NUM> of <FIG>, output channel sensors 1250a, 1250b are provided in each output channel 1230a, 1230b. The output channel sensors 1250a, 1250b are provided proximate to the junction of the input channel <NUM> and the corresponding output channel 1250a and may be used to facilitate timing of the actuation of the pumps. In this regard, the output channel sensors 1250a, 1250b may be used to detect a particle sorted for the corresponding channel to ensure that the sorted particle has reached a pre-determined point before the flow in the channel is stopped, slowed, or reversed for sorting of a subsequent particle. For example, with reference to <FIG>, prior to actuation of pump 140a for sorting of particle <NUM>, a controller may wait for a signal from an output channel sensor, such as output channel sensor 1250a, that the previous sorted particle <NUM> has reached a predetermined point within the output channel 130a or 1230a.

Referring now to <FIG>, an example system for categorizing of particles, which is not within the scope of the claims, is illustrated. The system <NUM> of <FIG> is similar to the example system <NUM> described above with reference to <FIG> and includes an input channel <NUM>, a sensor <NUM> and output channels 1330a, 1330b. In <FIG>, a single pump <NUM> may be provided for at least two output channels 1330a, 1330b. A single pump <NUM> may be provided for all output channels 1330a, 1330b. The flow in the output channels 1330a, 1330b may be stopped, slowed, or reversed via the actuation of valves 1350a, 1350b associated with each output channel 1330a, 1330b. In this regard, in order to stop, slow, or reverse flow in an output channel 1330a, 1330b, a controller (e.g., the controller <NUM> of <FIG>) may open the valve 1350a, 1350b associated with that channel to allow the pump <NUM> to flow fluid into the output channel, thus countering the flow from the input channel. In <FIG>, the pump <NUM> may flow fluid from a reservoir <NUM> into an output channel 1330a, 1330b through an open valve (e.g., valves 1350a, 1350b). The fluid in the reservoir <NUM> may be a dilutant, buffer, or carrier fluid, for example. The fluid in the reservoir is a dilutant which may facilitate further sub-categorization of particles in an output channel, as described above with reference to <FIG>.

Referring now to <FIG>, a schematic illustration of an example system for categorizing of particles is provided. In the example system <NUM> may be implemented in a microfluidic device, such as those described above with reference to <FIG>. The example system <NUM> includes a controller <NUM>. In various examples, the controller <NUM> may be implemented as hardware, software, firmware, or a combination thereof. In one example, the controller <NUM> is a processor coupled to or including a memory device.

The controller <NUM> is coupled to an input channel sensor <NUM>, such as the input channel sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the systems described above with reference to <FIG>. As described above, the input channel sensor <NUM> is provided to detect particles flowing through an input channel, where the input channel s coupled to at least two output channels to receive particles from the input channel. In this regard, the input channel sensor <NUM> may provide signals to the controller <NUM> indicative of the detection of a particle.

The controller <NUM> of the example system <NUM> of <FIG> is further coupled to a set of pumps <NUM>. In this regard, the pumps <NUM> include pumps corresponding to each of the at least two output channels. The example system <NUM> is provided for a system with two output channels and includes two pumps <NUM>, <NUM>, each pump <NUM>, <NUM> corresponding to an output channel. As described above, each pump <NUM>, <NUM> is operable to selectively slow, stop, or reverse flow of particles into the associated output channel from the input channel.

The controller <NUM> includes a particle categorization portion <NUM> to categorize a particle detected by the input channel sensor <NUM>. In various examples, the input channel sensor <NUM> may send a signal to the controller <NUM>, or the particle categorization portion <NUM> of the controller <NUM>, including a characteristic of the detected particle. The particle categorization portion <NUM> may use the received characteristic to categorize the particle into one of a set of at least two categories. Each category in the set of categories corresponds to an output channel.

The controller <NUM> further includes a pump selection portion <NUM> to selectively operate each pump <NUM>, <NUM>. In various examples, the pump selection portion <NUM> may select at least one pump for operation based on the categorization of the particle by the particle categorization portion <NUM>. As described above, the pump selection portion <NUM> may operate a pump corresponding to each output channel not associated with the category of the detected particle. Thus, flow into each output channel associated with a category that is different from the category of the detected particle is stopped, slowed, or reversed, causing the detected particle to be sorted into the remaining output channel.

Referring now to <FIG>, a flowchart illustrates a method for categorizing particles. The method <NUM> may be implemented in, for example, the controller <NUM> of system <NUM> of <FIG> or the controller <NUM> of <FIG>. The method <NUM> includes receiving a signal from an input channel sensor indicative of a detected particle (block <NUM>). As described above, with reference to <FIG>, a particle flowing through an input channel <NUM> may be detected by an input channel sensor <NUM>. The input channel sensor <NUM> may determine at least one characteristic of the detected particle and provide that characteristic in the signal.

At block <NUM>, the method <NUM> includes operating each pump associated with an output channel that corresponds to a category that is different from the category of the detected particle. As described above, the detected particle may be categorized into one of a set of at least two categories based on the characteristic received from the input channel sensor. Each category in the set of categories corresponds to an output channel. Based on the categorization of the detected particle, the pump associated with each output channel that corresponds to a category that is different from the category of the detected particle is activated to stop, slow, or reverse flow in that/those output channels. Thus, flow of the detected particle is directed to the appropriate output channel.

Referring now to <FIG>, a block diagram of a system is illustrated with a non-transitory computer-readable storage medium including instructions executable by a processor for particle categorizing. The system <NUM> includes a processor <NUM> and a non-transitory computer-readable storage medium <NUM>. The computer-readable storage medium <NUM> includes example instructions <NUM>-<NUM> executable by the processor <NUM> to perform various functionalities described herein. In various examples, the non-transitory computer-readable storage medium <NUM> may be any of a variety of storage devices including, but not limited to, a random access memory (RAM) a dynamic RAM (DRAM), static RAM (SRAM), flash memory, read-only memory (ROM), programmable ROM (PROM), electrically erasable PROM (EEPROM), or the like. In various examples, the processor <NUM> may be a general purpose processor, special purpose logic, or the like.

The example instructions include identify a selected category of a detected particle instructions <NUM>. In this regard, based on a signal from a sensor in an input channel, a detected particle may be categorized into the selected category from at least two categories. As described above, the input channel is coupled to at least two output channels, each output channel being associated with a category from the at least two categories.

The example instructions further include operate a pump associated with each output channel associated with a category that is different from the selected category of the detected particle instructions <NUM>. As described above, pumps corresponding to each output channel associated with a category that is different from the selected category of the detected particle may be operated to slow, stop, or reverse flow of particles into the associated output channel from the input channel. Thus, the detected particle may be sorted into the appropriate channels.

Software implementations of various examples can be accomplished with standard programming techniques with rule-based logic and other logic to accomplish various database searching steps or processes, correlation steps or processes, comparison steps or processes and decision steps or processes.

The foregoing description of various examples has been presented for purposes of illustration and description. The foregoing description is not intended to be exhaustive or limiting to the examples disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various examples. The examples discussed herein were chosen and described in order to explain the principles and the nature of various examples of the present disclosure and its practical application to enable one skilled in the art to utilize the present disclosure in various examples and with various modifications as are suited to the particular use contemplated. The features of the examples described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products.

Claim 1:
A system (<NUM>, <NUM>), comprising:
an input channel (<NUM>, <NUM>) having a first end and a second end to receive particles through the first end;
a sensor (<NUM>, <NUM>) to categorize particles in the input channel (<NUM>, <NUM>) into one of at least two categories;
at least two output channels (1130a, 1130b, 1230a, 1230b), each output channel fluidically coupled to the second end of the input channel (<NUM>, <NUM>) to receive particles from the input channel (<NUM>, <NUM>), each output channel (1130a, 1130b, 1230a, 1230b) being associated with at least one category of the at least two categories, each output channel having a corresponding pump (1140a, 1140b, 1240a, 1240b) operable, based on the categorization of a detected particle in a category associated with a different output channel (1130a, 1130b, 1230a, 1230b), to selectively slow, stop, or reverse a flow of particles into the output channel (1130a, 1130b, 1230a, 1230b) from the input channel (<NUM>, <NUM>),
an output channel sensor (<NUM>, 1250a, 1250b) provided in at least one of the at least two output channels (1130a, 1130b, 1230a, 1230b); and
a controller coupled to the sensor (<NUM>, <NUM>), to each pump (1140a, 1140b, 1240a, 1240b) and to the output channel sensor (<NUM>, 1250a, 1250b), wherein the controller is configured to:
receive a signal from the sensor indicative of categorization of a particle in a selected category of the at least two categories; and
selectively actuate (<NUM>) each pump corresponding to an output channel that is associated with a different category than the selected category, wherein the controller is configured to wait for a signal from the output channel sensor that the previous sorted particle has reached a predetermined point within the at least one output channel.