SIMPLE AUTOMATIC ELECTRONIC TOURNIQUET

• US 20140336697A1
• Filed: 12/05/2012
• Published: 11/13/2014
• Est. Priority Date: 12/07/2011
• Status: Active Grant

• Current Assignee: J Hewitt Incorporated
• Original Assignee: J Hewitt Incorporated
• Inventors: Masaki, Nobuyuki
• Granted Patent: US 9,662,121 B2
• Time in Patent Office: Days
• US Class Current: 606/203
• CPC Class Codes: A61B 17/132 Tourniquets sphygmomanometer A61B5/022
• CPC Class Codes: A61B 17/1322 comprising a flexible encircling member A61B17/135 takes precedence
• CPC Class Codes: A61B 17/135 inflatable for measuring blood pressure A61B5/022; inflatable pressure pads A61F5/34
• CPC Class Codes: A61B 17/1355 Automated control means therefor
• CPC Class Codes: A61B 5/02233 Occluders specially adapted therefor tourniquets A61B17/132
• CPC Class Codes: A61B 5/0225 the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: A61M 5/42 having means for desensitising skin, for protruding skin to facilitate piercing, or for locating point where body is to be pierced

Abstract

The present invention provides a simple auto electronic tourniquet which does not inflict pain on a person receiving tourniquet in the preparatory stage before venipuncture and which shorten the time required in preparation for venipuncture. The simple auto electronic tourniquet includes a manchette (wrapping member) wrapped around the upper arm and a controller provided on the manchette for controlling pressures to the upper arm by the wrapping member. The controller includes a diastolic blood pressure detecting circuit and a pressure setting and maintenance circuit The pressure setting and maintenance circuit setting pressures of the manchette at the time when changes of the biological signal are detected by the diastolic blood pressure detecting circuit as target pressures.

Claims

1. A simple auto electronic tourniquet comprising:

a wrapping member wrapped around any of the extremities of the human body and a controller provided on the wrapping member and controlling pressures applied to the extremity by the wrapping member;

the controller comprising a diastolic blood pressure detecting circuit and a pressure setting and maintenance circuit;

the diastolic blood pressure detecting circuit detecting changes of the biological signal concerning the diastolic blood pressure occurring in the extremity by controlling increase and decrease of pressures within the wrapping member;

the pressure setting and maintenance circuit setting the pressures of the wrapping member at the time when changes of the biological signal are detected by the diastolic blood pressure detecting circuit as target pressures and further controlling the wrapping member so as to make its pressures fall within the range similar to the target pressures.

2. A simple auto electronic tourniquet according to claim 1 wherein the pressure setting and maintenance circuit sets maximum pressures by adding predetermined allowable pressures to the target pressures, sets minimum pressures by reducing predetermined allowable pressures more than 0 (zero) from the target pressures, and thereby controls the wrapping member so as to make its pressures fall within the range similar to the target pressures by actively increasing and decreasing its pressures;

wherein when the pressure setting and maintenance circuit detects changes of the biological signal concerning the diastolic blood pressure occurring in the extremity in the pressure increase process, it sets the pressures of the wrapping member at the time of detection as target pressures and sets maximum pressures by adding predetermined allowable pressures to the target pressures;

wherein when the pressure setting and maintenance circuit detects changes of the biological signal concerning the diastolic blood pressure occurring in the extremity in the pressure decrease process, it sets the pressures of the wrapping member at the time of detection as target pressures and sets minimum pressures by reducing predetermined allowable pressures more than 0 (zero) from the target pressures, and thereby, the pressure setting and maintenance circuit resets the target pressures, the maximum pressures and the minimum pressures depending on changes of the diastolic blood pressure.

3. A simple auto electronic tourniquet according to claim 1, wherein the controller comprises a pressure switching decision circuit for determining to control not by the pressure setting and maintenance circuit but by a higher pressure setting and maintenance circuit in a case where pressures of the wrapping member are lower than predetermined pressures at the time when the diastolic blood pressure detecting circuit detects changes of the biological signal;

wherein the higher pressure setting and maintenance circuit detects changes of the biological signal occurring in the extremity by controlling so as to further increase pressures of the wrapping member at the time when the diastolic blood pressure detecting circuit detects changes of the biological signal, sets higher target pressures by reducing predetermined pressures from the pressures of the wrapping member at the time of detection, sets higher maximum pressure by adding predetermined allowable pressures to the higher target pressures, and sets higher minimum pressures by reducing predetermined allowable pressures more than 0 (zero) from the higher target pressures;

wherein when pressures of the wrapping member reach the higher maximum pressures, the higher pressure setting and maintenance circuit controls the wrapping member so as for its pressures to decrease, and when pressures of the wrapping member reach the higher minimum pressures, the higher pressure setting and maintenance circuit controls the wrapping member so as for its pressures to increase, and thereby, pressures of the wrapping member are maintained to the vicinities of the higher target pressures.

4. A simple auto electronic tourniquet according to claim 1, wherein the controller comprises a venipuncturability informing circuit, which, after a predetermined time from the point when a target pressure is set for the first time, outputs to a informing means a signal informing of venipuncture being possible.

5. A simple auto electronic tourniquet according to claim 1, wherein the controller comprises a tourniquet pressure abnormal informing circuit, which detects that pressures of the wrapping member become either higher than predetermined maximum management pressures or lower than predetermined minimum management pressures, and outputs to the informing means signals informing of tourniquet pressures being abnormal.

6. A simple auto electronic tourniquet according to claim 1, wherein the controller comprises an allowed tourniquet time expiration informing circuit, which starts measuring tourniquet times from the points when the first target pressures are set and which outputs signals informing that tourniquet times reach predetermined allowable tourniquet times to the informing means at the time of their reaching.

7. A simple auto electronic tourniquet according to claim 1, wherein the controller comprises a tourniquet discontinuance decision circuit, which shifts to a tourniquet discontinuance circuit in a case that changes of the biological signal cannot be detected by the diastolic blood pressure detecting circuit until pressures of the wrapping member reach predetermined pressures;

and

wherein the tourniquet discontinuance circuit controls so as to decrease in pressures of the wrapping member and outputs signals informing of tourniquet being impossible to the informing means.

8. A simple auto electronic tourniquet according to claim 1, wherein the controller comprises a tourniquet release circuit reducing pressures of the wrapping member based on signals emitted from a tourniquet release button;

and

wherein the tourniquet release button is further provided on a casing which covers the controller and/or is movably provided from the casing, and emits the signals to the tourniquet release circuit.

9. A simple auto electronic tourniquet according to claim 1, wherein the wrapping member comprises an air pump, a pressure control valve, a pressure sensor and a biological signal detecting sensor;

wherein the air pomp is a source of supply of the compressed air for obtaining pressures of the wrapping member;

wherein the pressure control valve adjusts pressures of the wrapping member by adjusting pressures of the air supplied from the air pump based on the command from the controller;

wherein the pressure sensor detects pressures of the wrapping member by pressures of the air within the wrapping member; and

wherein the biological signal detecting sensor detects the biological signal.

10. A simple auto electronic tourniquet according to claim 9, wherein a fixed or variable flow-regulating valve is provided for adjusting decreasing speed of pressures within the wrapping member by limiting a rate of flow of the air discharged from the wrapping member.