Obviousness

Obviousness Analysis of U.S. Patent 10,758,652 under 35 U.S.C. § 103

This analysis assesses whether the invention claimed in U.S. Patent 10,758,652 would have been obvious to a Person Having Ordinary Skill in the Art (POSA) at the time the invention was made (i.e., prior to the May 30, 2017 priority date). The analysis is based on the prior art references cited within the patent document itself.

A POSA in this context would be a biomedical engineer or a professional with substantial experience in the design and operation of apheresis and blood component separation systems.

Core Inventive Concept

The central inventive concept of US 10,758,652 is not the physical apparatus for apheresis, but rather the control method implemented by its controller. The patent's key contribution is a method and system that calculates the volume of pure plasma being collected in real-time by actively accounting for the volume of anticoagulant mixed with it. The collection process is terminated when a target volume of pure plasma is reached, rather than a target total volume of the plasma-anticoagulant mixture. This is intended to standardize the dose of collected plasma across donors with varying hematocrit levels and maximize collection yields within regulatory limits.

Obviousness Argument Based on a Combination of Prior Art

The independent claims (1 and 11) of patent '652 would have been obvious to a POSA by combining the teachings of a standard automated apheresis system with the well-understood principles of hematology and the clear motivation to optimize plasma collection under existing regulations.

1. The Base System - Automated Apheresis Technology

Numerous prior art references cited in the '652 patent describe the foundational technology for an automated plasmapheresis system. For example:

• US 4,086,924 A (assigned to Haemonetics Corp.): This early reference discloses a plasmapheresis apparatus for separating blood into components, including plasma, which is collected in a container. It establishes the basic process of drawing blood, separating it, and collecting a component.
• US 4,151,844 A (assigned to Baxter Travenol Laboratories, Inc.): This reference teaches a "method and apparatus for separating whole blood into its components and for automatically collecting one component." This establishes the concept of an automated system with a controller that manages the collection process and stops it once a condition is met. Such systems commonly use weight sensors to monitor the collected volume.

These references, and many others cited, establish that by 2017, the concept of a microprocessor-controlled apheresis machine with pumps, sensors (including collection container weight scales), and automated control loops was well-established. These systems had the capability to take donor parameters (like weight) as inputs to determine a target collection volume based on regulatory guidelines. However, this target was typically for the total volume of the anticoagulated plasma product.

2. The Known Problem and Motivation to Combine

The background section of the '652 patent itself articulates the problem that existed in the prior art and the motivation to solve it:

"Prior art plasma collection systems are unable to determine the total volume of plasma that has been collected (e.g., because the product collected is a mixture of plasma and anticoagulant) and, therefore collect based on the total collection volume, even if the total volume of plasma that has been collected is below the limit prescribed by the FDA." (Column 2, Lines 12-19)

A POSA would have been fully aware of this issue. It is a fundamental principle of apheresis that the collected plasma product is diluted by anticoagulant. It is also basic knowledge that the degree of this dilution for a given volume of processed whole blood depends on the donor's hematocrit (the volume percentage of red blood cells).

The motivation to solve this problem is twofold and compelling:

• Regulatory Compliance and Donor Safety: Regulatory bodies like the U.S. FDA set limits on the volume of plasma that can be safely donated. By measuring only the total mixed volume, prior art systems could inadvertently collect more pure plasma than the limit from a low-hematocrit donor or would have to set conservative limits, under-collecting from a high-hematocrit donor.
• Economic Efficiency: Plasma is a valuable commodity. A system that can more accurately collect the maximum allowable amount of pure plasma from every donor is more efficient and profitable.

This creates a strong motivation for a POSA to modify a standard automated apheresis system to account for the anticoagulant volume and thereby measure the "true" volume of collected plasma.

3. The Obvious Solution

Given the base automated system and the clear motivation, the solution claimed in the '652 patent is a predictable and obvious step. A POSA would know that a modern apheresis machine already possesses:

• A controller (microprocessor).
• A means to measure the total collected fluid (e.g., a weight sensor for the plasma collection container, as described in claim 16).
• A precisely controlled anticoagulant pump (where volume can be known from pump rotations, as described in claim 14).
• The ability to accept donor hematocrit as an input.

To implement the invention, a POSA would only need to program the existing controller to perform a simple, real-time calculation:

Volume_of_Pure_Plasma = Total_Monitored_Volume - Volume_of_Anticoagulant_Added

• Total Monitored Volume is provided by the existing weight scale on the plasma container.
• Volume of Anticoagulant Added is known because the system's controller is actively managing the anticoagulant pump. This volume is a direct function of the amount of whole blood processed.

The controller's new instruction would be to compare the calculated Volume_of_Pure_Plasma to the regulatory target volume and stop the procedure when the target is met. This requires no new hardware or non-obvious scientific breakthrough, but rather a straightforward application of programming to solve a known issue using existing system capabilities. The formula presented in the '652 patent specification to calculate the percentage of anticoagulant based on hematocrit is an application of basic principles of mixtures and concentrations that would be routine for a POSA in this field.

Conclusion

The invention of US patent 10,758,652 is rendered obvious under 35 U.S.C. § 103. The combination of a standard automated apheresis system (as taught by numerous prior art references like US 4,151,844 A) with the well-established knowledge of the dilutive effect of anticoagulant provides a clear motivation to create a more accurate collection method. The solution—programming the system's existing controller to subtract the known volume of anticoagulant from the measured total volume to find the pure plasma volume—is a predictable and logical step that would have been obvious to a person of ordinary skill in the art seeking to optimize plasma collection efficiency and regulatory compliance.