example of FIG. 3A, flow oscillator 42 includes a housing 58 and a flow diverting portion 52 configured to oscillate the flow of the fluid to generate an oscillating pressure differential. Flow diverting portion 52 includes a primary channel 54 configured to pass a majority of the flow of the fluid as a primary jet. Primary channel 54 may receive the primary jet of fluid from fluid inlet 44 and discharge at least a portion of the primary jet through fluid outlet 46. As shown, in some examples, primary channel 54 may be directly in line with flow from fluid inlet 44, which may enable primary channel 54 to be relatively resistant to clogging by tissue in the fluid. 

[0075] Flow diverting portion 52 also includes at least two secondary (e.g., feedback) channels 56 each configured to divert a portion of the flow of the fluid from a downstream portion of the primary jet from primary channel 54 to an upstream portion of the primary channel 54 as a secondary jet. These diverted secondary jets may intersect the primary jet, causing the primary jet to change a shape based on a pressure differential between the two secondary jets. The changed shape may cause a change in the pressure differential, such that the pressure differential oscillates between the secondary jets. In this way, the primary jet may oscillate within primary channel 54. These oscillations may generate vibrations, such as may be felt on housing 58. 

[0076] In some examples, fluid flow sensors discussed herein may generate flow- induced vibrations by diverting fluid within a fluid oscillator and oscillating a mechanical structure using the diverted fluid. FIG. 3B is a diagram of an example fluid flow sensor 60 that includes a fluid oscillator having a fluid diverting portion 72 and an oscillating portion 78. Fluid flow sensor 60 is an example of fluid flow sensor 16 of FIG. 1. Fluid flow sensor 60 may include a fluid inlet 64 configured to receive fluid from catheter 12. Fluid inlet 64 includes an inlet connector 68 that may be configured to couple to a fluid conduit such as aspiration tubing or a fluid switch. Fluid flow sensor 60 includes a fluid outlet 66 configured to discharge the fluid. Fluid outlet 66 includes an outlet connector 70 that may be configured to couple to a fluid conduit, such as aspiration tubing or a fluid pump. 

[0077] Fluid flow sensor 60 includes flow oscillator 62 configured to oscillate flow of the fluid through fluid flow sensor 60 to generate flow-induced vibrations. In the example of FIG. 3B, flow oscillator 62 includes a housing 84 and a flow diverting portion 72 configured to oscillate the flow of the fluid to generate an oscillating pressure differential. Flow diverting portion 72 includes a primary channel 74 and at least two secondary channels 76, which may be operably similar to flow diverting portion 52 

