Selecting limit values in particular for patient monitoring systems

• US 6,241,661 B1
• Filed: 08/05/1999
• Issued: 06/05/2001
• Est. Priority Date: 08/07/1998
• Status: Expired due to Term

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Marinow, Nikolai, Heusel, Philipp, Schluess, Rainer
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): Natnithithadha, Navin
• Application Number:
  US09/368,816
• Time in Patent Office: 670 Days
• Field of Search: 600/300, 600/301, 600/481, 600/508, 600/528, 600/529, 128/897
• US Class Current: 600/300
• CPC Class Codes: A61B 5/02455 provided with high/low alarm devices

Abstract

Disclosed is the selecting of a limit value, such as an alarm limit, from a range of limit values dependent on a starting value. The selected limit value is applicable e.g. in a patient monitoring system for monitoring a physiological parameter for providing a signal when a monitored value of the physiological parameter exceeds the selected limit value. According to the invention, the range of limit values comprises a functional range with a functional relationship of the limit values to the starting values, and at least one non-functional range with no functional relationship of the limit values to the starting values.

Claims

1. An apparatus for selecting a limit value from a range of limit values dependent on a starting value, whereby the selected limit value is applicable in a system for monitoring a physiological parameter for providing a signal when a monitored value of the physiological parameter exceeds the selected limit value, wherein, for at least one first range of starting values a value of the limit remains substantially constant over the first range of starting values, and for a second range of starting values the value of the limit varies as a function of the value of the starting value over the second range of starting values.

2. The apparatus of claim 1, wherein for said first range of starting values a value of a lowest upper limit in a range of upper limits remains substantially constant over the first range of starting values, and for said second range of starting values a value of a highest lower limit in a range of lower limits remains substantially constant over the second range of starting values.

3. The apparatus of claim 2, wherein the lowest upper limit value and the highest lower limit value define a range of uncritical values.

4. The apparatus according to claim 1, further comprising means for varying the distance of the range of limit values from a range of starting values.

5. A patient monitoring system for monitoring a physiological parameter of a patient, comprising the apparatus according to claim 1, whereby the selected limit value is used for providing a signal when a monitored value of the physiological parameter exceeds the selected limit value.

6. A method for selecting a limit value, whereby the selected limit value is applied in a system for monitoring a physiological parameter for providing a signal when a monitored value of the physiological parameter exceeds the selected limit value, the method comprising the steps of:

providing a range of limit values wherein, for at least one first range of starting values a value of the limit remains substantially constant over the first range of starting values, and for a second range of starting values the value of the limit varies as a function of the value of the starting value over the second range of starting values, and

selecting the limit value from the range of limit values dependent on a starting value.

7. An apparatus for selecting a limit value from a range of limit values dependent on a starting value, whereby the selected limit value is applicable in a system for monitoring a physiological parameter for providing a signal when a monitored value of the physiological parameter exceeds the selected limit value, wherein, for at least one first range of starting values a value of at least one of an upper limit or a lower limit remains substantially constant over the first range of starting values, and for a second range of starting values the values of both the upper limit and the lower limit vary as a function of the value of the starting value over the second range of starting values.