[0037] FIG. 3B is a diagram of a flow sensor that includes a fluid oscillator having a fluid diverting portion and an oscillating portion. [0038] FIG. 4 is a flow diagram of an example method of aspiration that includes generating flow-induced vibrations using a fluid flow sensor in response to receiving fluid flow from a catheter. [0039] FIG. 5 is an illustrative example graph of fluid flow versus time for an example aspiration procedure using aspiration system. [0040] The disclosure describes certain embodiments including a fluid flow sensor configured to generate haptic feedback that indicates and is driven by fluid flow from a catheter or through an aspiration system, as well as aspiration systems including the fluid flow sensor and the catheter and methods of using the aspiration systems. [0041] Thrombosis occurs when a thrombus (e.g., a blood clot or other embolus) forms and obstructs vasculature of a patient. To treat a patient with thrombosis, a clinician may position an aspiration catheter in a blood vessel of the patient near the thrombus, apply suction to the aspiration catheter, and engage the thrombus with a tip of the aspiration catheter. Once the tip of the aspiration catheter has engaged the thrombus, the clinician may remove the aspiration catheter with the thrombus attached to the tip or suction off pieces of the thrombus until the thrombus is removed from the blood vessel of the patient. The aspiration of the thrombus may be part of an aspiration procedure, such as, but not limited to, a medical procedure using A Direct Aspiration first Pass Technique (ADAPT) for acute stroke thrombectomy, or any other aspiration of thrombus or other material from the neurovasculature or other blood vessels. [0042] During placement of the aspiration catheter, a clinician may first position the aspiration catheter proximate an estimated location of the thrombus using a visual aid, such as an x-ray display or other medical imaging technique, and begin suctioning fluid through a lumen of the aspiration catheter into a canister. The clinician may reposition the aspiration catheter until the tip of the aspiration catheter encounters the thrombus. If the thrombus is relatively hard and fibrous, then the thrombus may block the distal opening of the catheter lumen (e.g., at a tip of the aspiration catheter) and cause a reduction or cessation of flow through the lumen of the aspiration catheter. If the thrombus is relatively soft, then the thrombus may initially block the distal opening of the catheter lumen until the thrombus begins to break apart in response to the application of DETAILED DESCRIPTION