# Leonarde Keeler's Early Mechanical Blood Pressure Recorder

> A 1925 invention by Leonarde Keeler designed to mechanically record a patient's arterial blood pressure over time.

- **Patent:** US 1788434
- **Original title:** Apparatus for recording arterial blood pressure
- **Owner:** Individual
- **Granted:** 1931
- **Status:** Public domain (expired)
- **Times cited:** 4
- **Field:** biotech, mechanical

## What it does

The device functions as a specialized mechanical apparatus for monitoring and documenting arterial blood pressure. It uses a pressure-sensitive mechanism to track fluctuations in a patient's pulse and blood flow. By translating these physical movements into a readable format, it allows clinicians to observe changes in pressure without constant manual observation.

## What it does NOT cover

- Does not cover electronic or digital blood pressure sensors.
- Does not cover automated cuff inflation systems found in modern monitors.
- Does not cover methods for analyzing blood pressure data using software or algorithms.

## The clever bit

The invention focuses on the mechanical translation of arterial pulses into a physical record, removing the need for a human to manually chart every point of pressure change in real-time.

## Real-world examples

1. Early mechanical sphygmograph prototypes
2. Analog clinical patient monitoring equipment

## Why it matters

This patent represents an early effort to move clinical diagnostics from subjective manual measurements to objective, recorded data. It highlights the transition toward continuous patient monitoring in medical settings.

## Frequently asked questions

### What does Leonarde Keeler's Early Mechanical Blood Pressure Recorder cover?

A 1925 invention by Leonarde Keeler designed to mechanically record a patient's arterial blood pressure over time.

### Who owns patent US 1788434?

Individual owns this patent, granted in 1931.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 1788434 cited by?

This patent has been cited by 4 later patents that build on its ideas.

### What problem does this patent solve?

This patent represents an early effort to move clinical diagnostics from subjective manual measurements to objective, recorded data. It highlights the transition toward continuous patient monitoring in medical settings.

### What does this patent NOT cover?

Does not cover electronic or digital blood pressure sensors.

**Full plain-English explainer:** https://patentbrief.org/patent/us/1788434/polygraph-lie-detector-keeler

**Original patent:** https://patents.google.com/patent/US1788434

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


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