Obviousness

Based on the provided patent documentation and prior art analysis, here is an assessment of the obviousness of US patent 12,377,204 under 35 U.S.C. § 103 as of April 26, 2026.

Definition of a Person Having Ordinary Skill in the Art (PHOSITA)

A person having ordinary skill in the art (PHOSITA) for this invention would be a biomedical engineer or a related professional with several years of experience in designing and developing blood apheresis systems. This individual would be knowledgeable about the principles of extracorporeal blood circulation, centrifugation, FDA regulations for plasma donation, and the physiological variables of donors, such as hematocrit and total blood volume.

Core Inventive Concepts of US Patent 12,377,204

The claims of the '204 patent are directed toward a system and method for plasma collection that combines two key features:

1. Personalized Collection Target: Calculating a donor-specific target collection volume based on the donor's height, weight, and hematocrit to determine their total plasma volume, and then targeting a specific percentage of that volume.
2. Accurate Pure Plasma Measurement: During the procedure, continuously calculating the volume of "pure plasma" (excluding anticoagulant) in the collection container by using the donor's specific hematocrit to determine the precise percentage of anticoagulant in the collected mixture. The procedure stops when this calculated pure plasma volume reaches the personalized target.

Obviousness Analysis

The claims of US patent 12,377,204 appear to be obvious in light of combinations of the prior art references. The following arguments demonstrate that a PHOSITA would have been motivated to combine the teachings of the prior art to arrive at the claimed invention with a reasonable expectation of success.

Argument 1: Obviousness over US 6,419,643 B1 in view of US 5,728,058 A

This combination establishes the obviousness of personalizing a plasma collection procedure where the collected volume is measured by accounting for anticoagulant.

• US Patent 6,419,643 B1 ('643 patent) teaches the foundational concept of personalizing an apheresis procedure. It explicitly discloses a system that uses a donor's specific height, weight, and hematocrit to automatically set procedure parameters, including collection targets. This directly teaches the first core concept of the '204 patent: setting a personalized collection target based on individual donor physiology.

• US Patent 5,728,058 A ('058 patent) teaches a method for accurately determining the volume of plasma collected by accounting for the volume of anticoagulant. It describes weighing the collection container and subtracting the calculated weight of the anticoagulant to find the weight of the "pure" plasma. This provides a known method for achieving the second core concept of the '204 patent: measuring the collected plasma exclusive of anticoagulant.

• Motivation to Combine: A PHOSITA starting with the '643 patent's system for personalizing collection targets would naturally seek an accurate method to measure the collected volume to ensure that the personalized target is met precisely. The '058 patent provides just such a method. The motivation would be to integrate the accurate measurement technique of the '058 patent into the personalized control system of the '643 patent. This would allow the system to stop the collection when the actual volume of pure plasma—not the total volume of the mixture—reaches the donor-specific target set according to the '643 patent's teachings.

This combination teaches all elements of the '204 patent's claims except for one refinement: using the donor's specific hematocrit to calculate the anticoagulant percentage in the collected product, rather than using the fixed ratio taught by the '058 patent.

Argument 2: Obviousness over the combination of US 6,419,643 B1 and US 5,728,058 A, further in view of US 7,052,482 B2

This stronger combination addresses the final element of the claims and renders them obvious.

• The Combination of '643 and '058: As established above, this combination yields a personalized apheresis system that calculates a pure plasma volume. A PHOSITA implementing this combination would recognize that the fixed anticoagulant-to-whole-blood ratio used in the '058 patent's calculation is a known source of inaccuracy, as it fails to account for the very donor-to-donor variability that the '643 patent aims to address.

• US Patent 7,052,482 B2 ('482 patent), assigned to Haemonetics itself, provides the solution. The '482 patent explicitly teaches that a donor's hematocrit is the key factor in determining the ratio of plasma to other components in their blood. It discloses that the amount of anticoagulant required is dependent on the plasma fraction, which is a direct function of hematocrit. The patent teaches adjusting apheresis parameters based on hematocrit to optimize the procedure.

• Motivation to Combine: A PHOSITA, seeking to improve the accuracy of the pure plasma calculation from the '058 patent within the personalized framework of the '643 patent, would be directly motivated by the '482 patent to use the donor's hematocrit for this purpose. The '482 patent teaches that hematocrit governs the plasma/anticoagulant relationship. It would have been obvious to a PHOSITA to apply this known principle to the calculation of the collected product. Instead of using the '058 patent's imprecise fixed ratio, the PHOSITA would use the donor's known hematocrit (already an input in the '643 system) to calculate a donor-specific percentage of anticoagulant in the collected plasma. This modification is a simple and predictable application of a known principle to improve a known method.

This three-way combination results in the exact method and system claimed in US patent 12,377,204:

1. A system that determines a donor's height, weight, and hematocrit to set a personalized target plasma collection volume (taught by '643).
2. A method that measures the collected plasma/anticoagulant mixture and calculates the volume of pure plasma (taught by '058).
3. An improvement where the pure plasma calculation uses the donor's specific hematocrit to determine the anticoagulant percentage in the collected mixture (an obvious modification of '058 in light of '482).

Therefore, a person having ordinary skill in the art would have been motivated to combine the teachings of these references to achieve a more accurate, personalized plasma collection system, and would have had a reasonable expectation of success in doing so.