Company: PFSA
Filing Date: 2025-10-09
Form Type: S-1
Source: 0001213900-25-097860
Chunk: 176

Company: Profusa, Inc.
Filing Date: 2025-10-09
Form: S-1
Chunk 176
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 be able to collect a stream of data allowing for the continuous monitoring of the biochemistry inside the body. This device is also designed to have the capability to measure multiple wavelengths of light allowing for the capture of changes in tissue optical properties and reference chemistry signals, providing input to the data algorithm to potentially correct for variability of subject tissue types and individuals change in tissue properties over time. Additionally, the reader is designed to be able to include thermistors, or temperature-sensitive resistors, and motion detectors, enabling the collection of additional parameters the algorithm may use to increase the accuracy of the analyte measurement. The externally worn device is designed to be a durable component of the system and can be reused for multiple sensor injections. 108

| ● | Data Algorithm |

Software algorithms operating in firmware and mobile applications compute clinically relevant values based on optical signals and temperature measurements provided by the reader hardware. Lumee Oxygen uses an oxygen sensor whose optical intensity, after excitation from an LED, decreases at a rate that is a function of tissue oxygen. The hardware is designed to provide rapid optical intensity measurements. The firmware fits the decrease in intensity to a model whose coefficients represent the oxygen intensity. The firmware produces a Lumee Oxygen Index (LOI) value every few seconds and the tablet application visualizes the data and determines the percent change over time. The glucose hydrogel is an intensity-based system with two dyes: a reference dye whose intensity is independent of glucose and other chemical properties of its environment, and a glucose dye whose intensity after excitation changes predictably with glucose concentration. The ratio of the glucose and reference intensity provides an approximation of the glucose signal. The glucose system is designed to use several wavelengths of light from defined LED sources and optical detectors. Every measurement sample includes 84 unique optical measurements that form a data set that is used to determine the glucose dye intensity, tissue optical properties, and position of the sensor. The hardware and firmware in the glucose system capture and store these raw measurements. The data processing on the glucose system is performed primarily on a mobile device. The mobile application computes glucose intensity changes and calibrates the values to establish a measurement of blood glucose. The glucose algorithm in the mobile application is designed to perform a series of corrections to account for changes in the optical signals that do not originate in the glucose dye. These include correcting for variability in the LED brightness at different temperatures; correcting for changes in the reader’s position relative to the sensor, by triangulating the position of the sensor using 4 opposing LEDs that excite the reference dye;