The goal of this observational study is to learn about the clinical utility of point-of-care ultrasound (POCUS) in patients receiving care in a free clinic or street medicine setting in Indianapolis. The main question it aims to answer is:

How often is POCUS used during patient encounters in a free clinic setting, and how does it influence clinical decision-making?

Participants who are receiving care from the street medicine team or the Indiana University School of Medicine Student Outreach Clinic and who undergo a clinically indicated POCUS exam as part of their regular medical care will have information from their ultrasound encounters recorded. Researchers will track the type of ultrasound performed, the findings, and whether the ultrasound changed the patient's medical management. Participants will also have a 30-day follow-up through electronic medical record review or phone/email contact to assess their clinical course and compare POCUS findings with any formal radiology studies if performed.

Street medicine is an emerging model of healthcare that provides health and social services directly to people experiencing unsheltered homelessness (PEH) in their own environments. Rather than requiring patients to come to a traditional clinic or hospital, street medicine practitioners meet individuals where they are-in alleyways, under bridges, in encampments, or other public spaces. Many cities have also incorporated formal brick-and-mortar, low-barrier free clinics to address acute and chronic healthcare concerns of the uninsured and unsheltered individuals of the community.

According to the 2025 PIT (Point-in-time) count, there were 1,815 individuals identified as PEH in Marion County. This represents a 7% increase from 2024 and is the highest total since 2021. Nationwide, this increase is even more alarming. In 2024, the PIT count identified 770,000 PEH, representing an 18% rise from the previous year. (IndyStar, 2025)

Point of care ultrasound (POCUS) is an underutilized resource in the street and free-clinic setting. Despite its long history of clinical application in the hospital setting, ultrasound has been limited in resource poor settings by portability, cost, and quality of image acquisition. Over the past 10 years, several advancements have shown allowed for the democratization of portable POCUS: improved image quality, AI integration, and wireless connectivity now exist in multiple handheld device models for only a few thousand dollars, which makes it possible to use in resource-limited settings. This technology both expedites diagnosis and reinforces the physician-patient relationship through its immediacy, portability, and facility of patient education as a visual aid. The convergence of street medicine and innovation in portable POCUS technology, particularly in the backdrop of an alarming increase in PEH across the nation, introduces a potential use-case in these settings.

However, there are limited data demonstrating the utility and efficacy of street-medicine POCUS. The purpose of this prospective observational study is to perform POCUS in the free clinic setting of Indianapolis, IN and catalogue the types of ultrasound exams performed based on already established chief-complaint driven indications. This will include 30-day follow up of relevant formal US comparison (if indicated) and overall clinical course. Additionally, this study serves to identify barriers to POCUS in these resource limited settings in order to formulate best practices for street medicine teams and free clinics moving forward.

Portable handheld ultrasound devices will allow the clinician to perform rapid bedside imaging to evaluate conditions related to common patient complaints including shortness of breath, chest pain, abdominal pain, flank pain, soft tissue infections, joint injuries, or suspected blood clots. The ultrasound exams will typically take 2-5 minutes and may include thoracic, cardiac, abdominal, renal, vascular, soft tissue, musculoskeletal, ocular, or obstetric/gynecologic imaging depending on the patient's symptoms. The goal is to assist clinical decision-making in real time while improving access to diagnostic imaging in resource-limited free clinic and street medicine environments.

Inclusion Criteria:

• Patients >18 years old
• Presenting to either: street medicine team in Indianapolis, IN OR patients presenting to free clinic in Indianapolis, IN, AND Being treated by the Primary Investigatory AND Meeting one or more of specific indications (see study design)

Exclusion Criteria:

• Patients <18 years old
• Patients unable to provide verbal consent
• Patient refusal of ultrasound