MedTech UI Logic Validation: Ensuring 100% Patient Safety During React Migrations

A single rounding error in a dosage calculator or a delayed telemetry alert isn't just a bug in MedTech—it’s a sentinel event. When healthcare enterprises move from monolithic legacy systems (Delphi, Silverlight, or ancient Java Swing) to modern React architectures, the greatest risk isn't the UI aesthetics; it's the invisible business logic buried in the source code. If that logic isn't captured perfectly, patient safety is compromised.

The industry standard for manual migration is failing. With 70% of legacy rewrites exceeding their timelines or failing entirely, the traditional "document, then code" approach is too slow and too prone to human error. MedTech logic validation ensuring patient safety requires a shift from manual interpretation to automated visual reverse engineering.

TL;DR: Manual migration of MedTech UIs takes 40+ hours per screen and carries high risks of logic regression. Replay uses Visual Reverse Engineering to convert recorded user workflows into documented React components, reducing migration time by 70% while ensuring 100% logic parity. This process is essential for HIPAA and SOC2 compliant environments where "medtech logic validation ensuring" safety is the top priority.

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The $3.6 Trillion Technical Debt Crisis in Healthcare#

The global technical debt has ballooned to $3.6 trillion, and nowhere is this more felt than in healthcare. Many critical patient management systems are built on frameworks that reached end-of-life a decade ago. These systems are "black boxes"—the original developers are gone, and 67% of these legacy systems lack any form of up-to-date documentation.

When a hospital system decides to modernize, they usually face an 18-to-24-month roadmap. During this time, the risk of "logic drift"—where the new React component behaves slightly differently than the legacy UI—is astronomical.

Visual Reverse Engineering is the process of using computer vision and AI to analyze the behavior, state changes, and logic of a legacy application's user interface from a video recording, subsequently generating functional code that matches the original performance.

By using Replay, organizations can bypass the "archeology phase" of modernization. Instead of digging through 20-year-old COBOL or C# scripts, architects record the application in use. Replay captures the flows, the edge cases, and the validation logic, ensuring the new React frontend is a "pixel-perfect and logic-perfect" twin.

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Why MedTech Logic Validation Ensuring Safety is Non-Negotiable#

In a regulated environment, "it looks the same" is not a valid test result. MedTech logic validation ensuring patient safety involves verifying that every conditional state—such as "If Patient Age < 12, then adjust dosage limit"—is preserved exactly.

The Documentation Gap#

According to Replay’s analysis, the primary cause of logic failure in migrations is the "Interpretation Gap." A business analyst watches a legacy screen, writes a requirement, and a React developer implements it. In this three-step chain, 20-30% of the original logic nuance is often lost.

Video-to-code is the process of converting a screen recording of a legacy software workflow directly into production-ready React components and documented design systems.

Industry experts recommend that for any Class II or Class III medical device software migration, the validation suite must include side-by-side behavioral audits. This is where Replay’s "Flows" feature becomes critical. It maps the architectural journey of a user, ensuring that every state transition in the legacy system is accounted for in the new React architecture.

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Manual Migration vs. Replay: The Data#

The following table compares the traditional manual rewrite approach against the automated Visual Reverse Engineering approach provided by Replay.

For a deeper dive into the risks of traditional methods, see our article on The Hidden Costs of Legacy Modernization.

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Implementing MedTech Logic Validation Ensuring Parity in React#

When migrating to React, the goal is to move the logic into a maintainable, testable structure. Replay doesn't just give you "spaghetti code" from a video; it generates structured TypeScript components.

Example: Legacy Validation vs. Modern React Validation#

In a legacy system, validation might be buried in a 500-line jQuery file or a WinForms event handler. Replay identifies these triggers. Here is how that logic is transformed into a robust React component using Zod for schema validation—ensuring that medtech logic validation ensuring patient safety is baked into the type system.

typescript
// Generated via Replay AI Automation Suite
import React from 'react';
import { useForm } from 'react-hook-form';
import { z } from 'zod';
import { zodResolver } from '@hookform/resolvers/zod';

// Logic captured from Legacy Telemetry System
const DosageSchema = z.object({
  patientWeight: z.number().min(0.1, "Weight required"),
  medicationType: z.enum(["Insulin", "Heparin", "Saline"]),
  dosageAmount: z.number().max(500, "Exceeds safety threshold"),
}).refine((data) => {
  // Logic extracted from legacy 'dosage_calc.dll'
  if (data.medicationType === "Insulin" && data.dosageAmount > 50) {
    return false;
  }
  return true;
}, {
  message: "Critical Safety Alert: Insulin dosage exceeds patient weight ratio",
  path: ["dosageAmount"],
});

export const DosageEntry: React.FC = () => {
  const { register, handleSubmit, formState: { errors } } = useForm({
    resolver: zodResolver(DosageSchema),
  });

  const onSubmit = (data: any) => {
    console.log("Validated MedTech Data:", data);
  };

  return (
    <form onSubmit={handleSubmit(onSubmit)} className="p-4 bg-slate-50 border-red-200">
      <label>Patient Weight (kg)</label>
      <input {...register("patientWeight", { valueAsNumber: true })} />
      {errors.patientWeight && <span className="error">{errors.patientWeight.message}</span>}
      
      {/* Replay-generated UI matching legacy design system */}
      <button type="submit">Submit Dosage</button>
    </form>
  );
};

Capturing State Transitions with Replay Flows#

One of the hardest things to replicate is the "State Machine" of a medical UI. For instance, what happens to the UI when a heart rate monitor disconnects? Replay's Flows feature documents these asynchronous states by analyzing the video frames and network calls.

Learn more about Visual Reverse Engineering and how it maps complex application states.

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Technical Architecture for Regulated Environments#

MedTech companies cannot simply send their patient data to a public cloud AI. Replay is built for regulated industries, offering:

1. •SOC2 & HIPAA Readiness: Data handling that meets the strictest US healthcare standards.
2. •On-Premise Availability: Keep your source code and recordings within your own secure perimeter.
3. •Audit Trails: Every component generated by Replay can be traced back to the original recording, providing a "Source of Truth" for FDA auditors.

According to Replay's analysis, enterprises using automated logic extraction see a 90% reduction in "P0" bugs during the UAT (User Acceptance Testing) phase of migration. This is because the medtech logic validation ensuring safety is performed at the component level before the system is even integrated.

typescript
// Example of an Automated Test Case generated from a Replay Blueprint
describe('MedTech Logic Validation: Alert Thresholds', () => {
  it('should trigger a high-priority alert when systolic pressure > 180', () => {
    const { getByText, getByLabelText } = render(<VitalsMonitor />);
    
    const input = getByLabelText(/systolic/i);
    fireEvent.change(input, { target: { value: '185' } });
    
    // Validating that the React component matches legacy alert behavior
    expect(getByText(/CRITICAL: Hypertensive Crisis/i)).toBeInTheDocument();
    expect(document.body).toHaveClass('alert-active-high');
  });
});

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The Replay Workflow: From Recording to React#

How does Replay achieve a 70% time saving? The workflow is designed to replace the manual "discovery" phase of a project.

1. •Record: A subject matter expert (SME) records themselves performing standard and edge-case workflows in the legacy application.
2. •Analyze (The Library): Replay’s AI extracts the Design System—buttons, inputs, colors, and typography—and stores them in the Replay Library.
3. •Map (Flows): The architectural connections between screens are mapped out, creating a visual blueprint of the application’s logic.
4. •Generate (Blueprints): The platform generates clean, documented React code that mirrors the legacy behavior but uses modern best practices (Tailwind CSS, TypeScript, etc.).
5. •Validate: Developers use the generated documentation to perform medtech logic validation ensuring that the new system is a perfect functional match.

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Reducing the "Risk of the Unknown"#

In legacy systems, logic is often hidden in "side effects." For example, clicking "Save" might trigger a background calculation that updates three other tables and sends a notification to a nurse's station.

Industry experts recommend that modernization teams focus on "Functional Parity" rather than "Feature Parity." Feature parity asks "Does it have a save button?" Functional parity asks "Does the save button initiate the exact same sequence of 12 safety checks as the 1998 version?"

Replay’s AI Automation Suite is specifically tuned to identify these sequences. By analyzing the visual feedback of the legacy system, Replay can infer the underlying logic gates, making medtech logic validation ensuring safety a transparent process rather than a guessing game.

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Frequently Asked Questions#

How does Replay handle HIPAA compliance when recording medical software?#

Replay is built with security-first principles. We offer on-premise deployments where no data leaves your network. Additionally, our platform is SOC2 compliant and designed to handle Sensitive Personal Information (SPI) by allowing users to redact or mask sensitive UI elements during the recording process.

Can Replay extract logic from legacy systems like Delphi or VB6?#

Yes. Because Replay uses Visual Reverse Engineering, it is "language agnostic." It doesn't need to read your 20-year-old source code to understand how the UI behaves. By observing the inputs and outputs at the UI level, Replay can reconstruct the component logic in modern React.

What is the difference between Replay and a standard AI code assistant?#

Standard AI assistants (like Copilot) require you to provide the context or the code. Replay generates the context by observing your legacy system in action. It captures the "how" and "why" of your application's behavior, which is often missing from the source code itself.

How much time can we actually save on a MedTech migration?#

On average, our partners see a 70% reduction in total project time. Specifically, the time spent on UI development and documentation drops from 40 hours per screen to approximately 4 hours per screen. This allows teams to focus on high-value integrations rather than tedious UI rebuilding.

Does Replay generate unit tests for the new React components?#

Yes, the Replay AI Automation Suite can generate test suites (Jest/Cypress) based on the recorded flows. This ensures that the medtech logic validation ensuring safety is continuously verified throughout the CI/CD pipeline.

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Conclusion: Modernize with Confidence#

The transition from legacy systems to React is a necessity for healthcare providers who want to leverage AI, cloud scalability, and modern UX. However, the path is fraught with risks that manual processes cannot mitigate.

By leveraging Replay, MedTech organizations can ensure that their logic validation is not just a checkbox, but a mathematically and visually verified reality. Don't let your modernization project become another "failed rewrite" statistic. Use Visual Reverse Engineering to bridge the gap between your legacy reliability and your modern future.

Ready to modernize without rewriting? Book a pilot with Replay