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US 8,805,511 B2Granted
Method and apparatus to detect subcerebral ischemia
AssigneeMedtronic, Inc.
InventorsMustafa Karamanoglu, Vincent E. Splett, Nancy J. Rakow, Linnea R. Lentz
Life of this patent
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Abstract
A medical device and associated method detect ischemia using stimulation delivered to induce respiration. A spontaneous breathing response to the stimulation-induced respiration is determined. Ischemia is detected in response to the spontaneous breathing response. The spontaneous breathing response is measured as a response to adjusting a parameter controlling the stimulation.
Claims15
A method for detecting ischemia, the method comprising:
- delivering stimulation to a phrenic nerve to induce respiration;
- determining a spontaneous breathing response to stimulation;
- detecting ischemia in response to the spontaneous breathing response;
- adjusting a parameter controlling delivery of the stimulation;
- detecting a change in spontaneous breathing in response to adjusting the parameter;
- and
- comparing the change in spontaneous breathing to a previously detected change in spontaneous breathing determined in response to adjusting the parameter,
- the ischemia detected in response to the comparison.
5 more elements
A method for detecting ischemia, the method comprising:
- delivering stimulation to a phrenic nerve to induce respiration;
- determining a spontaneous breathing response to stimulation;
- and
- detecting ischemia in response to the spontaneous breathing response,
- wherein adjusting the parameter comprises at least one of increasing a stimulation rate, decreasing a stimulation rate, starting stimulation, stopping stimulation, adjusting a stimulation pulse amplitude, adjusting a stimulation pulse number, and adjusting a stimulation pulse train frequency.
2 more elements
A method for detecting ischemia, the method comprising:
- delivering stimulation to a phrenic nerve to induce respiration;
- determining a spontaneous breathing response to stimulation;
- and
- detecting ischemia in response to the spontaneous breathing response,
- wherein determining the spontaneous breathing response comprises determining a spontaneous breathing response measurement by determining at least one of a stimulation parameter at which spontaneous breathing disappears, a stimulation parameter at which spontaneous breathing reappears, a time interval between a stimulation induced breath and a spontaneous breath, a spontaneous breathing rate, a spontaneous breathing tidal volume, and a parameter indicative of a metabolic status of the patient.
2 more elements
A method for detecting ischemia, the method comprising:
- delivering stimulation to a phrenic nerve to induce respiration;
- determining a spontaneous breathing response to stimulation;
- and
- detecting ischemia in response to the spontaneous breathing response,
- measuring a parameter correlated to venous pH,
- wherein detecting ischemia comprises identifying a change in a sensitivity of the spontaneous breathing response to venous pH compared to a previous spontaneous breathing response.
3 more elements
A method for detecting ischemia, the method comprising:
- delivering stimulation to a phrenic nerve to induce respiration;
- determining a spontaneous breathing response to stimulation;
- and
- detecting ischemia in response to the spontaneous breathing response,
- wherein determining the spontaneous breathing response comprises:
- measuring a first value of a metabolic status parameter corresponding to a disappearance of spontaneous breathing in response to the stimulation inducing respiration;
- measuring a second value of the metabolic status parameter corresponding to a reappearance of spontaneous breathing in response to adjusting the stimulation inducing respiration;
- and
- detecting a shift of at least one of the first value and the second value relative to a value of the metabolic status parameter previously measured during a known non-ischemic condition;
- the ischemia being detected in response to the detected shift.
7 more elements
A medical device for detecting ischemia, comprising:
- a medical lead for delivering stimulation to induce respiration;
- a sensor sensing a signal correlated to patient respiration;
- a control processor configured to receive the sensor signal, determine a spontaneous breathing response to the stimulation, and detect ischemia in response to the spontaneous breathing response,
- wherein the control processor is configured to adjust a parameter controlling delivery of the stimulation,
- detect a change in spontaneous breathing in response to adjusting the parameter, and
- compare the change in spontaneous breathing to a previously detected change in spontaneous breathing,
- the ischemia detected in response to the comparison.
4 more elements
A medical device for detecting ischemia, comprising:
- a medical lead for delivering stimulation to induce respiration;
- a sensor sensing a signal correlated to patient respiration;
- a control processor configured to receive the sensor signal, determine a spontaneous breathing response to the stimulation, and detect ischemia in response to the spontaneous breathing response,
- wherein the control processor is configured to adjust a parameter controlling delivery of the stimulation,
- detect a change in spontaneous breathing in response to adjusting the parameter, and
- compare the change in spontaneous breathing to a previously detected change in spontaneous breathing,
- the ischemia detected in response to the comparison,
- wherein adjusting the parameter comprises at least one of increasing a stimulation rate, decreasing a stimulation rate, starting stimulation, stopping stimulation, adjusting a stimulation pulse amplitude, adjusting a stimulation pulse number, and adjusting a stimulation pulse train frequency.
5 more elements
A medical device for detecting ischemia, comprising:
- a medical lead for delivering stimulation to induce respiration;
- a sensor sensing a signal correlated to patient respiration;
- a control processor configured to receive the sensor signal, determine a spontaneous breathing response to the stimulation, and detect ischemia in response to the spontaneous breathing response;
- and
- a pH sensor for measuring a parameter correlated to venous pH,
- the control processor configured to receive the measured parameter,
- wherein detecting ischemia comprises identifying a change in a sensitivity of the spontaneous breathing response to venous pH compared to a previous spontaneous breathing response.
4 more elements
A medical device for detecting ischemia, comprising:
- a medical lead for delivering stimulation to induce respiration;
- a sensor sensing a signal correlated to patient respiration;
- a control processor configured to receive the sensor signal, determine a spontaneous breathing response to the stimulation, and detect ischemia in response to the spontaneous breathing response;
- and
- a pH sensor for measuring a parameter correlated to venous pH,
- the control processor configured to receive the measured parameter,
- wherein detecting ischemia comprises identifying a change in a sensitivity of the spontaneous breathing response to venous pH compared to a previous spontaneous breathing response,
- a sensor for providing a signal to the control processor correlated to a metabolic status parameter of the patient,
- wherein determining the spontaneous breathing response comprises
- measuring a first value of a metabolic status parameter corresponding to a disappearance of spontaneous breathing in response to the stimulation inducing respiration;
- measuring a second value of the metabolic status parameter corresponding to a reappearance of spontaneous breathing in response to adjusting the stimulation inducing respiration;
- and
- detecting a shift of at least one of the first value and the second value relative to a value of the metabolic status parameter previously measured during a known non-ischemic condition,
- the ischemia being detected in response to the detected shift.
11 more elements
A medical device for detecting ischemia, comprising:
- a medical lead for delivering stimulation to induce respiration;
- a sensor sensing a signal correlated to patient respiration;
- a control processor configured to receive the sensor signal, determine a spontaneous breathing response to the stimulation, and detect ischemia in response to the spontaneous breathing response;
- and
- a pH sensor for measuring a parameter correlated to venous pH,
- the control processor configured to receive the measured parameter,
- wherein detecting ischemia comprises identifying a change in a sensitivity of the spontaneous breathing response to venous pH compared to a previous spontaneous breathing response,
- a sensor for providing a signal to the control processor correlated to a metabolic status parameter of the patient,
- wherein determining the spontaneous breathing response comprises
- measuring a first value of a metabolic status parameter corresponding to a disappearance of spontaneous breathing in response to the stimulation inducing respiration;
- measuring a second value of the metabolic status parameter corresponding to a reappearance of spontaneous breathing in response to adjusting the stimulation inducing respiration;
- and
- detecting a shift of at least one of the first value and the second value relative to a value of the metabolic status parameter previously measured during a known non-ischemic condition,
- the ischemia being detected in response to the detected shift,
- wherein the metabolic status parameter comprises at least one of a blood pH and a minute ventilation.
12 more elements
A computer-readable non-transitory medium storing instructions which cause a medical device to perform a method, the method comprising:
- delivering stimulation to induce respiration;
- determining a spontaneous breathing response to the stimulation;
- detecting ischemia in response to the spontaneous breathing response;
- adjusting a parameter controlling delivery of the stimulation;
- detecting a change in spontaneous breathing in response to adjusting the parameter;
- and
- comparing the change in spontaneous breathing to a previously detected change in spontaneous breathing determined in response to adjusting the parameter,
- the ischemia detected in response to the comparison.
5 more elements
Dependencies are inferred from the claim text.