PHOTOPLETHYSMOGRAPHIC BLOOD PRESSURE MEASURING DEVICE WITH REMOVABLE FINGER CUFF

Abstract

The blood pressure measuring device (1) is designed as a photoplethysmographic measuring system which functions according to the “vascular unloading technique”. Metrological components and a pressure generating and pressure control system are accommodated in the base part (3). The fitted cuff part (2) has an ergonomic palm support (4), two finger supports (6) divided from one another by a web (5), and also a receiving part (7) which comprises two receiving tubes (9) for fingers. The cuff part (2) projects beyond the base part (3), both towards the front and also towards the rear, and covers the base part (3) almost completely, i.e. by more than 90%. The lateral attachment of the cable (8) facing in the direction of the forearm has the advantage that the cable can be guided along the patient's arm, the wrist does not rub against the cable (8), and in particular the carpal tunnel is also protected.

Claims

1. A measuring device for continuous determination of intra-arterial blood pressure on at least one finger of a hand, which comprises: a base part, a cuff part which is connectable to the base part without tools and separatable from the base part without tools and which comprises at least one ring-like receiving tube for receiving a portion of a finger of a hand passed through the receiving tube, and at least one cuff pad which is arranged in the receiving tube and fillable with a fluid, a radiation source for emitting light into the finger through an optical emission surface, a photodetector for detecting a portion of the light collected by an optical collector surface and not absorbed in the finger, and a pressure control system disposed at least partially in the base portion for controlling a fluid pressure in the cuff pad in response to the detected non-absorbed portion of the light, wherein the cuff part further comprises a palm rest for supporting the palm of the hand and at least one finger rest associated with each of the at least one receiving tube, respectively, for supporting the portion of the finger protruding beyond the respective receiving tube, and the cuff part projects beyond the base part in the longitudinal direction towards the front and towards the rear, the longitudinal direction being defined as the direction of intended insertion of the finger into the receiving tube or of the fingers into the receiving tubes, the palm rest being arranged behind and the at least one finger rest being arranged in front of the receiving tube.

2. The measuring device according to claim 1, wherein the base part does not project beyond the cuff part in the transverse direction over at least the major part of the length of the base part.

3. The measuring device according to claim 2, wherein the cuff part completely covers the base part in at least one projection plane, in particular a projection plane parallel to both the longitudinal and transverse directions, if a cable connection possibly extending from the base part is not considered part of the base part.

4. The measuring device according to any one of the preceding claims, wherein the palm rest comprises a convex curvature in longitudinal direction on the side intended to face the hand.

5. The measuring device according to any one of the preceding claims, wherein the at least one finger rest comprises a respective concave curvature in the transverse direction on the side intended to face the hand.

6. The measuring device according to any one of the preceding claims, wherein a) the entirety of the at least one receiving tube(s), b) the entirety of the at least one finger rest, and c) the palm rest are, on their side intended to face the hand, each symmetrical with respect to a common longitudinal axis.

7. The measuring device according to any one of the preceding claims, wherein the base part comprises a cable connection which is oriented in such a way that the axial direction of a connected cable in its central position, i.e. without deflection of the cable, points obliquely backwards relative to the longitudinal direction of the measuring device at an angle of between 5 and 45 degrees when the angle lies in a horizontal angle plane or is projected onto a horizontal angle plane, and/or which is off-center with respect to the width of the base part.

8. The measuring device according to claim 7, wherein the angle is between 10 and 30 degrees.

9. The measuring device according to claim 7 or claim 8, wherein the cable connection is arranged in the region of the base part which is covered by the palm rest in a direction perpendicular to the longitudinal and transverse directions.

10. The measuring device according to one of the preceding claims, wherein all edges of the receiving tube(s) are rounded and/or chamfered.

11. The measuring device according to any one of the preceding claims, wherein all outer edges of the receiving tube(s) are rounded and/or chamfered.

12. A system comprising a measuring device according to any one of claims 1-11, and at least one further cuff part interchangeable with the cuff part without tools, comprising at least one ring-like receiving tube for receiving a portion of a finger of a hand passed through the receiving tube, and at least one fluid-fillable cuff pad arranged in the receiving tube, a palm rest for supporting the palm of the hand, and at least one finger rest associated with each of the at least one receiving tube for supporting the portion of the finger extending beyond the respective receiving tube, wherein the receiving tube and/or the at least one finger rest and/or the palm rest of the cuff part and of the further cuff part are dimensioned differently from one another, respectively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG. 1 shows a measuring device according to the invention in a side view, wherein a cuff part comprising an ergonomic hand rest and a finger-receiving part is placed on a base part containing a pressure control system,

[0040] FIG. 2 shows a perspective view of the measuring device of FIG. 1 from obliquely above,

[0041] FIG. 3 shows a perspective view of the measuring device of FIG. 1 from obliquely below,

[0042] FIG. 4 shows a cuff part like the one shown in FIG. 3 from obliquely below, but without the associated base part, the cuff pads not being shown,

[0043] FIG. 5 shows a view of the measuring device from FIG. 1 from behind, i.e. from the left in FIG. 1,

[0044] FIG. 6 shows the measuring device of FIG. 1 in plan view.

[0045] The blood pressure measuring device 1 is designed as a photoplethysmographic measuring system which functions according to the so-called “Vascular Unloading Technique”. Measuring components, i.e. in particular optical and electronic components as well as mechanical components of the pressure generation and pressure control system accommodated in the base part 3, can be implemented in principle in a manner similar to the prior art mentioned at the beginning. The cuff part placed on the base part 3 comprises an ergonomic palm rest 4, two ergonomic finger rests 6 separated from each other by a web 5, and a receiving part 7 comprising two receiving tubes 9 for receiving two fingers, as shown in FIG. 2 and FIG. 5. The finger rests 6 have a concave curvature in their transverse direction so that the fingers can each rest comfortably thereon. The edges at the rims of the receiving tubes 9 are chamfered.

[0046] According to the above definition, the left side of FIG. 1 corresponds to the direction indication “rear”, the right side of FIG. 1 corresponds to the direction indication “front”. Accordingly, the upper side of FIG. 6 corresponds to the direction indication “rear”, the lower side of FIG. 6 corresponds to the direction indication “rear”.

[0047] As can be seen in FIG. 1, the palm rest 4 comprises a convex curvature in the longitudinal direction at the top (i.e. on the side facing the patient's hand as intended) in order to improve ergonomics. In this region, the palm rest also has a convex curvature in the transverse direction. In an end area (left in FIG. 1), a region curved concavely in the longitudinal direction is provided for the heel of the hand.

[0048] The cuff part 2 protrudes beyond the base part 3 both to the front and to the rear. As can be seen from FIG. 6, the cuff part 2 covers the base part 3 almost completely, i.e. to an extent of more than 90%.

[0049] As shown in the perspective view of FIG. 2 (viewed from obliquely above at the right in FIG. 1), the receiving part 7 is designed to receive two fingers, which makes alternate measurement on both fingers possible. For reasons of hygiene, the cuff part 2, together with the palm rest 4 and finger rest 6, is designed as a disposable article which is detachably, without tools, attached to the reusable base part 3 by means of a plug-in connection.

[0050] The pressure control system in the base part 3 is supplied with compressed air via the obliquely laterally attached cable 8, which points in the direction of the forearm when the hand is placed on the base part as intended. Furthermore, the cable 8 serves to supply energy to the pressure control system (not shown), light sources (not shown) and photodetectors (not shown) or associated control, amplifier and evaluation circuits in the measuring device 1. Measurement data can be output to a patient monitor via a suitable electronic interface through the cable 8.

[0051] The lateral attachment of the cable 8, pointing in the direction of the forearm when the hand is placed as intended, has the advantage that the cable can be guided along the patient's arm, but the wrist area with tendons and vessels does not rub against the cable 8, and in particular the carpal tunnel is also protected.

[0052] As can be seen in FIG. 6, the central axis of the undeflected cable 8, indicated by a dot and dash line, forms an angle α of here 17 degrees and thus between 10 and 30 degrees with the longitudinal axis x corresponding to the longitudinal direction of the cuff part.

[0053] The entirety of the receiving tubes 9, i.e. the receiving part 7, as well as the finger rests 6 and the palm rest 9 are symmetrical with respect to the longitudinal axis x of the cuff part. Thus, the cuff part is equally suitable for the right and left hand.

[0054] The two inflatable cuff pads 10 arranged in the receiving tubes 9 are each connected to the pressure generation and pressure control system via a port 11 at the interface between cuff part 2 and base part 3. In the illustration of cuff part 2 in FIG. 4, one of the two ports 11 is hidden by the crosspiece 12, which carries light guides 13 through which light is conducted from the light sources arranged in base part 3 to the fingers or from the fingers to the photosensors arranged in base part 3. A valve device is preferably located at port 11, so that port 11 is flush with the housing of base part 3 on the base part side when base part 3 and cuff part 2 are not connected to each other.