Company: PFSA
Filing Date: 2025-05-13
Form Type: S-4/A
Source: 0001213900-25-042224
Chunk: 435

Company: Profusa, Inc.
Filing Date: 2025-05-13
Form: S-4/A
Chunk 435
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’s passive sensor is composed of a class of materials called hydrogels, which are similar to the material from which modern contact lenses are made. The sensor is designed to overcome the effect of the foreign body response and thus has been demonstrated to be able to collect biochemical data for up to 6 -monthsin the case of Lumee Oxygen, and up to 9 -monthsbased on the data acquired through Profusa’s glucose program clinical study. This hydrogel scaffolding is soft and pliable and serves as the base material on which specific fluorescent molecules are bound. These fluorescent molecules bind specifically to the analyte of interest and their fluorescent characteristics change depending on whether the analyte is bound or unbound. The hydrogel sensors are devoid of any electronics or power source, and are simply composed of the hydrogel scaffolding and the fluorescence sensing chemistry. Depending on the sensor type, Profusa may also imbed a reference chemistry for reference purposes during data processing. The hydrogel sensor measures approximately 400 microns in diameter by 3 millimeters in length and is injected subcutaneously via a hypodermic needle injection at a depth of 2 – 6 millimeters from the surface. Upon injection, the sensor is designed to be integrated as a part of the tissue and is not noticeable. As this sensor is passive in nature, while the binding and unbinding of the analyte of interest is constantly occurring, data from the sensor is not actively broadcasted outside of the body until a reader (described below) is placed on the skin over the sensor. By “decoupling the sensor and the reading elements,” we believe that our approach has a few major advantages: 1.The cost of the system is quite low as the sensors are low cost to manufacture and the more expensive reader component can be reused through multiple sensor injections; 2.The act of data acquisition is controlled by the user and action is secure; 3.The sensor deployment is a common hypodermic needle procedure that can be performed by healthcare professionals across a variety of common settings; and 4.The sensor functionality lifetime is limited by the stability of the fluorescence molecule and not by the foreign body response, which translates into months of functionality. • Reusable Reader An optical reader has been developed to be worn on the skin above the sensor and is designed to interrogate and gather sensor signal for data processing. This optical reader has a small wearable form factor dimensions of the oxygen reader and is worn on the skin via a double -sidedmedical grade adhesive. The