DCT
1:25-cv-01854
Reisinger v. Forensic Fluids Inc
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Amy J. Reisinger (Pennsylvania)
- Defendant: Forensic Fluids, Inc. and Bridget Lorenz Lemberg (Michigan)
- Plaintiff’s Counsel: Acker Wood Intellectual Property Law, LLC
- Case Identification: 1:25-cv-01854, W.D. Mich., 12/19/2025
- Venue Allegations: Venue is based on Defendant Forensic Fluids, Inc. being incorporated in Michigan with its principal place of business in the district, and Defendant Bridget Lorenz Lemberg residing in the district.
- Core Dispute: Plaintiff alleges that Defendants’ forensic toxicology services infringe three patents related to methods for detecting and quantifying drugs of abuse in post-mortem subjects using oral fluid as the testing matrix.
- Technical Context: The technology operates in the field of post-mortem forensic toxicology, providing an alternative to traditional testing of blood, urine, or tissue samples to determine the presence and concentration of drugs in deceased subjects.
- Key Procedural History: The complaint alleges that Plaintiff and Defendant Lemberg discussed Plaintiff's patented technology at a Society of Forensic Toxicology conference in late 2022. It also alleges that Defendant Lemberg left Plaintiff a voicemail in September 2025 asking, "you're not going to sue me are you?", which may be presented as evidence of pre-suit knowledge for the purposes of willfulness.
Case Timeline
| Date | Event |
|---|---|
| 2014 | Plaintiff founds SteelFusion Clinical Toxicology Laboratory, LLC. |
| 2015-06-19 | U.S. Patent No. 9,366,685 Priority Date |
| 2016-05-25 | U.S. Patent No. 9,817,006 Priority Date |
| 2016-06-14 | U.S. Patent No. 9,366,685 Issues |
| 2017-10-17 | U.S. Patent No. 10,267,811 Priority Date |
| 2017-11-14 | U.S. Patent No. 9,817,006 Issues |
| 2019-04-23 | U.S. Patent No. 10,267,811 Issues |
| 2022-10-30 | Plaintiff and Defendant Lemberg allegedly discuss patented technology at SOFT conference. |
| 2024-03-30 | Alleged start date of infringing activity. |
| 2025-09-18 | Defendant Lemberg allegedly leaves voicemail for Plaintiff regarding potential lawsuit. |
| 2025-12-19 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,366,685 - "Rapid and Sensitive Method of Forensic Toxicology in Post-Mortem Subjects Using Oral Fluid Testing"
- Patent Identification: U.S. Patent No. 9,366,685, "Rapid and Sensitive Method of Forensic Toxicology in Post-Mortem Subjects Using Oral Fluid Testing," issued June 14, 2016.
The Invention Explained
- Problem Addressed: The patent describes the challenges of traditional post-mortem forensic drug analysis, which relies on biological matrices like blood, urine, and liver tissue. These methods are invasive, and sample retrieval can be difficult in decaying cadavers. Furthermore, drug redistribution after death can lead to inaccurate concentration measurements depending on the sample site (ʼ685 Patent, col. 1:24-52).
- The Patented Solution: The invention proposes using oral fluid from a post-mortem subject as the testing matrix. The claimed method comprises collecting an oral fluid sample, performing a qualitative analysis with an enzyme-linked immunosorbent assay (ELISA) to screen for drugs, and then performing a quantitative analysis with Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS) to determine specific drug concentrations (ʼ685 Patent, Abstract; col. 2:57-68).
- Technical Importance: This approach provided a less invasive and potentially more consistent alternative for post-mortem toxicology, aiming to yield faster and more sensitive results than methods reliant on traditional matrices affected by decomposition (Compl. ¶16).
Key Claims at a Glance
- The complaint asserts infringement of all six claims, with Claim 1 being the sole independent claim (Compl. ¶34).
- Claim 1 recites a method with the essential elements of:
- collecting a sample of oral fluid from a post-mortem human subject;
- analyzing the sample qualitatively using an ELISA method to detect drugs;
- analyzing the sample quantitatively using an LC-MS/MS method to determine drug concentration;
- identifying the detected drugs;
- wherein the detection and quantification is "more sensitive and faster" than that from blood, urine, bile, and liver tissue from the same subject;
- wherein the drugs are selected from a specified list (e.g., amphetamine, fentanyl, THC); and
- wherein results are obtained in "as soon as three hours."
- The complaint explicitly asserts infringement of dependent claims 2-6, which add limitations regarding the specific location of oral fluid collection (e.g., buccal cavity, sublingual region), collection time, and sample volume (Compl. ¶¶37-41).
U.S. Patent No. 9,817,006 - "Rapid and Sensitive Method of Forensic Toxicology in Post-Mortem Subjects Using Oral Fluid Testing"
- Patent Identification: U.S. Patent No. 9,817,006, "Rapid and Sensitive Method of Forensic Toxicology in Post-Mortem Subjects Using Oral Fluid Testing," issued November 14, 2017.
The Invention Explained
- Problem Addressed: The patent addresses the same issues as the ʼ685 Patent: traditional post-mortem drug testing methods are invasive, slow, and can yield inconsistent results due to post-mortem drug redistribution (ʼ006 Patent, col. 1:24-54).
- The Patented Solution: The invention claims a method for testing post-mortem oral fluid that streamlines the process by focusing on quantitative analysis. Unlike the ʼ685 Patent, the independent claim of the ʼ006 Patent does not require a preliminary qualitative screening step (e.g., ELISA) and proceeds directly to quantitative analysis using LC-MS/MS to determine drug concentrations (ʼ006 Patent, Abstract; col. 2:14-24).
- Technical Importance: This patented method represents a more direct analytical approach, leveraging the high specificity of LC-MS/MS for both detection and quantification without a separate screening step (Compl. ¶18).
Key Claims at a Glance
- The complaint asserts infringement of all six claims, with Claim 1 being the sole independent claim (Compl. ¶50).
- Claim 1 recites a method with the essential elements of:
- collecting a sample of oral fluid from a post-mortem human subject;
- analyzing the sample quantitatively using an LC-MS/MS method to determine drug concentration;
- identifying the detected drugs;
- wherein the detection and quantification is "more sensitive and faster" than that from blood, urine, bile, and liver tissue from the same subject;
- wherein the drugs are selected from a specified list (e.g., amphetamine, fentanyl, THC); and
- wherein quantitative results are obtained in "as soon as three hours."
- The complaint explicitly asserts infringement of dependent claims 2-6, which add limitations parallel to those in the ʼ685 Patent concerning collection location, time, and volume (Compl. ¶¶53-57).
U.S. Patent No. 10,267,811 - "Rapid and Sensitive Method of Forensic Toxicology in Post-Mortem Subjects Using Oral Fluid Testing"
- Patent Identification: U.S. Patent No. 10,267,811, "Rapid and Sensitive Method of Forensic Toxicology in Post-Mortem Subjects Using Oral Fluid Testing," issued April 23, 2019.
Technology Synopsis
This patent addresses the same technical problems as its parent patents but narrows the method's application to a specific context. It claims a method for quantifying drugs in oral fluid collected from a post-mortem human subject who is "suspected of dying from taking a drug overdose," using LC-MS/MS for the analysis (ʼ811 Patent, Abstract; col. 2:1-12). This added element of "suspicion of...drug overdose" frames the technical method within a specific diagnostic purpose.
Asserted Claims
All six claims are asserted, with Claim 1 being the sole independent claim (Compl. ¶66).
Accused Features
The complaint alleges that because Defendants' services test for drugs of abuse in deceased subjects, it logically follows that such testing is undertaken due to a suspicion of a drug overdose, thereby infringing this patent (Compl. ¶67).
III. The Accused Instrumentality
Product Identification
- The "Accused Forensic Services" are forensic toxicology testing services provided by Defendants (Compl. ¶5).
Functionality and Market Context
- The services allegedly involve the collection and analysis of oral fluid from post-mortem subjects to detect and quantify drugs of abuse (Compl. ¶20). The complaint alleges Defendants' process includes collecting a sample using a "Quantisal collection device," performing an initial screen using an ELISA method, and confirming results quantitatively with an LC-MS/MS method (Compl. ¶¶21-22). Exhibit F, a document retrieved from Defendants' website, provides instructions for collecting a sample from a postmortem subject's buccal cavity (Compl. ¶21). Exhibit G, a screenshot from the website, states that Defendants use "enzyme linked immunosorbent assay (ELISA) for all drug screens and LC/MS/MS quantification for confirmation" (Compl. ¶22). Defendants market these services to coroners and medical examiners, allegedly with a turnaround time of 24 hours or less (Compl. ¶24).
IV. Analysis of Infringement Allegations
U.S. Patent No. 9,366,685 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| collecting a sample of oral fluid from a post-mortem human subject; | Defendants' services include collecting oral fluid from a post-mortem subject using a collection pad, as detailed in instructional documents provided to clients. | ¶36 | col. 2:62-63 |
| analyzing the oral fluid sample qualitatively using an enzyme-linked immunosorbent assay (ELISA) method...; | Defendants' website allegedly states they use an ELISA method for all drug screens. | ¶36 | col. 2:64-66 |
| analyzing the oral fluid sample quantitatively using a Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS) method...; | Defendants' website allegedly states they use LC-MS/MS for quantification for confirmation of positive results. | ¶36 | col. 2:66-68 |
| wherein detection and quantification in oral fluid is more sensitive and faster than detection and quantification of the non-naturally occurring drugs in blood, urine, bile, and liver tissue...; | Defendants' marketing materials allegedly advertise a rapid turn-around time of 24 hours or less. | ¶36 | col. 2:5-9 |
| wherein the one or more non-naturally occurring drugs are selected from the group consisting of amphetamine...[etc.] | Defendants' publicly available drug list for post-mortem testing allegedly includes drugs from the claimed group. | ¶36 | col. 4:18-35 |
| wherein qualitative and quantitative results are obtained in as soon as three hours. | Defendants' marketing materials allegedly advertise a turn-around time of 24 hours or less, which the complaint asserts meets this limitation. | ¶36 | col. 4:36-37 |
U.S. Patent No. 9,817,006 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| collecting a sample of oral fluid from a post-mortem human subject; | Defendants' services include collecting oral fluid from a post-mortem subject using a collection pad, as detailed in instructional documents. | ¶52 | col. 2:14-15 |
| analyzing the oral fluid sample quantitatively using a Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS) method...; | Defendants' website allegedly states they use LC-MS/MS for quantification. | ¶52 | col. 2:15-19 |
| wherein detection and quantification in oral fluid is more sensitive and faster than detection and quantification of the non-naturally occurring drugs in blood, urine, bile, and liver tissue...; | Defendants' marketing materials allegedly advertise a rapid turn-around time of 24 hours or less. | ¶52 | col. 2:23-29 |
| wherein the one or more non-naturally occurring drugs are selected from the group consisting of 6-acetylmorphine...[etc.] | Defendants' publicly available drug list for post-mortem testing allegedly includes drugs from the claimed group. | ¶52 | col. 4:1-21 |
| wherein quantitative results are obtained in as soon as three hours. | Defendants' marketing materials allegedly advertise a turn-around time of 24 hours or less, which the complaint asserts meets this limitation. | ¶52 | col. 4:22-24 |
- Identified Points of Contention:
- Evidentiary Questions: Both asserted independent claims require proof that the oral fluid method is "more sensitive and faster" than testing on matrices "collected from the same post-mortem human subject." A central question will be what level of proof is required to satisfy this comparative limitation. The complaint relies on general marketing claims of speed (e.g., a 24-hour turnaround time) rather than direct, side-by-side comparisons for a given subject (Compl. ¶¶36, 52). This raises the question of whether such general marketing evidence is sufficient to prove infringement.
- Scope Questions: Dependent claims in both patents require sample collection "in about one minute to about ten minutes" (Compl. ¶¶40, 56). The complaint alleges infringement by citing Defendants' instructions, which state to "wait for the indicator to turn blue or approximately 15 minutes" (Compl. ¶¶40, 56). A dispute may arise over whether "approximately 15 minutes" falls within the scope of "about ten minutes."
V. Key Claim Terms for Construction
The Term: "more sensitive and faster"
Context and Importance: This comparative limitation is present in the independent claims of both the ʼ685 and ʼ006 Patents and is central to the invention's purported advance over the prior art. Its construction will determine the evidentiary burden on the Plaintiff, specifically whether direct, subject-by-subject comparison data is required to prove infringement.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The Abstract and Summary of the Invention sections describe the method's overall superiority in general terms, which may support an argument that the phrase refers to a general capability of the method rather than a required outcome for every specific application (ʼ685 Patent, Abstract; col. 2:1-12).
- Evidence for a Narrower Interpretation: The claim language itself specifies the comparison is to other matrices "collected from the same post-mortem human subject" using the same analytical methods (ʼ685 Patent, col. 4:12-18). This language may support a narrower construction requiring proof of superior sensitivity and speed via a direct, controlled comparison for each instance of alleged infringement.
The Term: "about one minute to about ten minutes"
Context and Importance: This term from dependent claim 5 of both patents defines the claimed collection time. Practitioners may focus on this term because the complaint's evidence for infringement is a document instructing users to wait "approximately 15 minutes" (Compl. ¶¶40, 56), creating a potential mismatch.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the collection process as observing a pad for saturation "for approximately two to ten minutes" (ʼ685 Patent, col. 7:4-5). The use of "approximately" and the inherent variability of achieving saturation in a biological sample may support construing "about ten minutes" to encompass a wider range, including fifteen minutes.
- Evidence for a Narrower Interpretation: The Summary of the Invention states that fluid "is collected in about one minute to about ten minutes" (ʼ685 Patent, col. 2:60-62). This explicit recitation of the range, without the qualifier "approximately," could be used to argue for a stricter interpretation where fifteen minutes is outside the claimed scope.
VI. Other Allegations
- Indirect Infringement: While not pleaded as a separate count, the facts alleged may support a claim for induced infringement. The complaint states that Defendants offer their services to coroners and medical examiners and provide instructional documents, such as Exhibit F, on how to perform the initial "collecting a sample" step of the claimed methods (Compl. ¶¶20-21). Providing instructions and materials to a third party (the client) to perform a claimed step could form the basis for an inducement allegation.
- Willful Infringement: The complaint alleges willful infringement based on pre-suit knowledge (Compl. ¶¶46, 62, 78). The alleged basis includes a 45-minute conversation between Plaintiff Reisinger and Defendant Lemberg at a 2022 toxicology conference regarding Plaintiff's oral fluid technology, as well as an alleged voicemail from Lemberg to Reisinger in September 2025 asking, "you're not going to sue me are you?" (Compl. ¶¶19, 31). Willfulness is also alleged based on notice provided by the complaint itself (Compl. ¶¶43, 59, 75).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of evidentiary proof: can the "more sensitive and faster" limitation be proven with general marketing materials about the accused service's speed, or will the claim language requiring a comparison to matrices from the "same post-mortem human subject" necessitate direct, side-by-side empirical data for each act of infringement?
- A key question of claim scope will be whether the temporal limitation "about ten minutes" for sample collection can be construed to read on the accused service's instruction to wait "approximately 15 minutes," a determination that will likely influence the infringement analysis for the asserted dependent claims.
- The willfulness analysis will likely depend on factual discovery into the 2022 conference discussions and the 2025 voicemail to determine if Defendants had the specific, pre-suit knowledge of the patents and their infringement required to support an enhancement of damages.