Automatic tourniquet
First Claim
1. A pneumatic tourniquet comprising:
- (a) an inflatable cuff;
(b) pressure sensing means for producing a first signal representative of the pressure in said cuff;
(c) means for producing a second signal representative of a selected pressure;
(d) means responsive to said first and second signals for determing a pressure adjustment related to the selected pressure and the sensed pressure, said means for determining further including a means for varying said pressure adjustment dependent on the magnitude of the difference between said selected pressure and said sensing pressure, and for providing a third signal representative of said pressure adjustment; and
(e) means responsive to said third signal for adjusting the pressure in said cuff.
4 Assignments
0 Petitions
Accused Products
Abstract
A pneumatic tourniquet which automatically adjusts the pressure in the tourniquet cuff and in which the pressure adjustment is variable and depends on the sign and magnitude of the pressure error. There is an inflatable cuff, a motor and pump for inflating the cuff, a valve for deflating the cuff, a transducer for sensing the pressure in the cuff, and a switch for setting a desired cuff pressure. A microprocessor is responsive to signals from the transducer and switches to calculate a duty cycle related to the pressure error. The microprocessor periodically applies a signal to the motor or valve during the calculated duty cycle to provide an adjustment to cuff pressure related to pressure error. The microprocessor also is responsive to motor speed and accumulated error history to provide further adjustments to the pressure.
42 Citations
9 Claims
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1. A pneumatic tourniquet comprising:
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(a) an inflatable cuff; (b) pressure sensing means for producing a first signal representative of the pressure in said cuff; (c) means for producing a second signal representative of a selected pressure; (d) means responsive to said first and second signals for determing a pressure adjustment related to the selected pressure and the sensed pressure, said means for determining further including a means for varying said pressure adjustment dependent on the magnitude of the difference between said selected pressure and said sensing pressure, and for providing a third signal representative of said pressure adjustment; and (e) means responsive to said third signal for adjusting the pressure in said cuff. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification