Method and measuring system for continuously determining the intra-arterial blood pressure

Inventors

Fortin, Jürgen • Fortin, Andrea • Popp, Klaus

Assignees

CNSystems Medizintechnik GmbH

Abstract

The invention describes a measuring system for the continuous non-invasive determination of blood pressure at one or more fingers. The fingers chosen for measurement and the adjacent parts of the palm rest on a supporting surface of a housing, which has the shape of a computer mouse. Inside the housing of the “CNAP Mouse”, i.e. underneath the supporting surface for the hand, the pressure generating system is located. The finger sensors are mounted on the supporting surface for the hand. The forearm and the back of the hand are left free and may be used to place intra-venous or intra-arterial access elements. Since the hand will rest on the supporting surface motion artefacts are largely avoided. Tilting or turning of the sensors is hardly possible since the fit of the sensors and thus the coupling of light and pressure are optimized.

Core Innovation

The invention relates to a “CNAP Mouse” measuring system for continuous determination of intra-arterial blood pressure at two fingers of a hand having a palm. A double-finger sensor having inflatable cuffs is used together with a plethysmographic system comprising at least two light sources with one or more wavelengths and at least two light detectors. The measuring system performs continuous non-invasive determination of intra-arterial blood pressure using Vascular Unloading.

A pressure generating system comprising at least one valve is controlled in real time by the plethysmographic system. The valve generates pressure in the cuffs so that the pressure corresponds to the intra-arterial blood pressure in the finger and is available over a frequency range having an upper limit frequency of at least 20 Hz. The system includes pressure generation with a real-time controlled valve-based pressure generating system.

The measuring system is packaged in a housing having an upper supporting surface configured to support the two fingers and adjacent areas of the palm, with a curved outer profile and a flat bottom surface configured to rest on a supporting plane. The double-finger sensor projects from the upper supporting surface, and the pressure generating system with the controlled valve is located in the housing underneath the upper supporting surface.

The upper supporting surface comprises a receiving slot that partitions the upper supporting surface mirror-symmetrically into two partial surfaces. The receiving slot contains elements for connecting the plethysmographic system to the double-finger sensor, with two outer elements disposed in the receiving slot slideable in the direction of a central element, and the part of the double-finger sensor that accommodates the inflatable cuffs is fastened to the outer elements in a removable and exchangeable manner.

Claims Coverage

The document includes two independent claims. Across these claims, the coverage centers on a continuous intra-arterial blood pressure measuring system using a double-finger inflatable cuff sensor with an optical plethysmographic system and a real-time valve-controlled pressure generating system, packaged in a mouse-like housing with a receiving slot and slideable, removable optical sensor elements, with the valve located under the upper supporting surface.

Overall, the claims cover a continuous intra-arterial blood pressure measuring system that couples a double-finger inflatable cuff sensor to an optical plethysmographic system and a real-time valve-controlled pressure generating system, with the housing geometry, receiving slot, slideable outer elements, removable and exchangeable cuff mounting, and placement of the pressure generating system underneath the upper supporting surface.

Stated Advantages

Documented Applications