US 12174106

Analysis of U.S. Patent 12,174,106: Flow Cytometer

Date of Analysis: May 13, 2026

Patent Number: US 12,174,106 B2

Title: Flow cytometer

Assignee: Beckman Coulter, Inc.

Inventor: Yong Qin Chen

Filing Date: December 22, 2021

Issue Date: December 24, 2024

Abstract:
The present disclosure relates to the field of flow cytometry, detailing an improved flow cytometer and its various subassemblies. The invention introduces a simplified and reliable diode laser-based optical system that produces a focused laser beam with an elliptical cross-section, optimized for flow cytometric applications. It also describes an imaging quality microscope objective with a long working distance, large numerical aperture, and minimal chromatic aberration. Additionally, the patent presents a simple and reliable fluidics system capable of supporting velocity-critical applications, a novel peristaltic pump design for pulseless liquid flow, and a reconfigurable Wavelength Division Multiplexing (WDM) system for separating a light beam into multiple colored bands.

Plain-Language Overview of Independent Claims

An independent claim represents the broadest definition of the invention. US Patent 12,174,106 contains several independent claims covering different aspects of the flow cytometer system.

Claim 1: A Complete Flow Cytometer System
This claim describes a comprehensive flow cytometer system that integrates several key innovations. The system includes:

• An optical system using a laser diode (LD) to create a specialized elliptical light beam to illuminate particles in a fluid stream.
• A composite microscope objective, featuring a unique concave mirror and an aberration-correcting aspheric lens, to efficiently collect light scattered and fluoresced from the particles.
• A fluidic subsystem designed to provide a smooth, pulsation-free sheath flow that hydrodynamically focuses the sample liquid.
• A specialized peristaltic pump to deliver the sample liquid.
• A wavelength division multiplexer (WDM) to separate the collected light into different colors for analysis.

In essence, claim 1 protects the entire integrated flow cytometer apparatus that combines these novel components to achieve improved performance.

Claim 15: An Optical System for Particle Illumination
This claim focuses on the optical system used to illuminate the particles. It details an arrangement with at least two different colored light sources. The key innovation is the use of a "chromatic compensation element." When using multiple lasers of different colors, the focal points can shift slightly, a phenomenon known as chromatic aberration. This element corrects for that shift, ensuring that both laser beams are precisely focused on the same plane where the particles are flowing. This allows for more accurate and consistent multi-color analysis of the particles.

Claim 18: An Optical System with a Unique Microscope Objective
This claim centers on a specific configuration of the optical system that includes a novel composite microscope objective. The system comprises:

• A light source to illuminate particles in the viewing zone.
• The composite microscope objective itself, which uses a combination of a concave mirror and a special "aberration corrector plate" (an aspheric lens with both positive and negative power zones).
• A beam splitter.

The arrangement allows the light source and the image detector to be on opposite sides of the beam splitter, enabling a compact design where the illumination and light collection occur from the same general direction relative to the sample. The unique design of the objective ensures high-quality imaging with a large field of view and high light-collection efficiency.

Claim 21: An Axial Light Detection System
This claim protects a system for measuring "axial light loss." As a particle passes through the laser beam, it blocks some of the light. This system uses a concave mirror to collect the light that passes by the particle and directs it to a detector. By measuring the decrease in light, the system can determine properties of the particle, such as its size. This method provides an effective way to analyze the physical characteristics of the particles.

Claim 23: A Power Monitoring System for Multiple Lasers
This claim describes a system to monitor and stabilize the power of multiple lasers in the flow cytometer. It uses a series of dichroic filters (which reflect some colors of light and let others pass) to direct a small sample of each laser beam to a single detector. The system uses "time-division multiplexing," meaning it measures the power of each laser one at a time in a rapid sequence. A control unit then adjusts the power of each laser based on these measurements, ensuring the illumination remains constant and reliable, which is critical for accurate data collection.

Claim 26: A Combined Objective and Wavelength Division Multiplexer (WDM) System
This claim covers the integration of the novel composite microscope objective with a specialized WDM. The objective, with its concave mirror and aspheric lens, gathers light from the illuminated particle. This light is then sent, often via an optical fiber, to the WDM. The WDM uses a series of optical elements to collimate the light (make the rays parallel) over an extended path and then uses dichroic filters to split it into different color bands, each focused onto a detector. This combination allows for efficient collection and precise spectral analysis of the faint fluorescent signals from the particles.

Claim 28: A More Detailed Optical System
This claim provides a more detailed description of an optical system that combines the illumination source, the unique composite microscope objective (concave mirror and aspheric lens), an optical fiber to transmit the collected light, and a multiplexer to separate the light into at least two colors. It essentially protects the complete light path from illumination of the object to the spectral separation of the collected signal.

Claim 29: An Apparatus for Imaging Objects in a Flow System
This claim focuses on the core imaging apparatus. It includes:

• A fluid delivery system to bring an object (like a cell) to a specific "viewing zone."
• A light source to illuminate the object.
• The key components of the composite microscope objective: a concave mirror on one side of the viewing zone and the special aspheric lens on the other side.

This claim protects the fundamental combination of the fluidics and the novel objective design for the purpose of creating a high-quality image of the scattered and fluorescent light from the object.

Litigation Status

A search of the CAFC (Court of Appeals for the Federal Circuit) dockets for 2026 for "US 12174106" did not yield any specific results. However, the provided patent document from Google Patents indicates that this patent family has been involved in litigation. Specifically, it notes:

• A Post-Grant Review (PGR) case, PGR2025-00084, filed with the Patent Trial and Appeal Board (PTAB).
• A U.S. District Court case filed in the Delaware District Court, 1:24-cv-00945.

As of the current date, I do not have access to the outcomes or current status of these proceedings beyond what is noted in the provided source. Authoritative information on ongoing litigation would require a direct search of the respective court docketing systems (PTAB E2E and PACER for the district court).