Calibrated Systems, Devices and Methods for Preventing, Detecting, and Treating Pressure-Induced Ischemia, Pressure Ulcers, and Other Conditions

Patent metadata

Field	Value
Publication number	US-2016296159-A1
Application number	US-201615183739-A
Country	US
Kind code	A1
Filing date	Jun 15, 2016
Priority date	Apr 22, 2010
Publication date	Oct 13, 2016
Grant date	—

Abstract

A system for monitoring medical conditions including pressure ulcers, pressure-induced ischemia and related medical conditions comprises at least one sensor adapted to detect one or more patient characteristic including at least position, orientation, temperature, acceleration, moisture, resistance, stress, heart rate, respiration rate, and blood oxygenation, a host for processing the data received from the sensors together with historical patient data to develop an assessment of patient condition and suggested course of treatment. In some embodiments, the system can further include a support surface having one or more sensors incorporated therein either in addition to sensors affixed to the patient or as an alternative thereof. The sensor can include bi-axial or tri-axial accelerometers, as well as resistive, inductive, capactive, magnetic and other sensing devices, depending on whether the sensor is located on the patient or the support surface, and for what purpose. Compensation for errors introduced because of chest angle or slope can be automatically performed.

First claim

We claim:

1 . A method for calibrating a sensor, wearable by a patient for monitoring patient movement and position, outputting acceleration data comprising
providing to a processor a correction factor to adjust for an angle of the sensor relative to a rotational axis of a patient, providing to a processor data representative of acceleration measured by the sensor, applying, in the processor, the correction factor to the data representative of sensor acceleration in a rotation matrix, outputting corrected acceleration data representative of patient position with respect to the rotational axis of the patient, and determining in a processor orientation of the patient using the corrected acceleration data.

2 . The method of claim 1 wherein the rotational axis is a longitudinal axis and the angle of the sensor relative to the rotational axis is pitch.

3 . The method of claim 1 wherein the rotational axis is a lateral axis and the angle of the sensor relative to the lateral axis is roll.

4 . The method of claim 2 wherein the acceleration data represents acceleration along three axes.

5 . The method of claim 1 wherein the correction factor is based on patient-specific data.

6 . The method of claim 5 wherein the patient-specific data comprises chest angle relative to the patient's longitudinal axis of rotation.

7 . The method of claim 5 wherein the patient-specific data comprises chest angle relative to the patient's lateral axis of rotation.

8 . The method of claim 1 wherein the correction factor is predetermined.

9 . The method of claim 8 where the correction factor is predetermined based on a range of known patient measurements.

10 . The method of claim 2 wherein the rotation matrix is applied along the Y axis.

11 . The method of claim 3 wherein the rotation matrix is applied along the X axis.

12 . A method for calibrating a sensor, wearable by a patient for
monitoring patient movement and position, outputting acceleration data comprising providing to a processor at least one correction factor to adjust for pitch and roll angles of the sensor relative to longitudinal and rotational axes of a patient, providing to a processor data representative of multi-axis acceleration measured by the sensor, applying, in the processor, the at least one correction factor to the data representative of sensor acceleration in a rotation matrix applied along a first axis to correct for pitch angle and in a rotation matrix along a second axis to correct for roll angle, outputting corrected acceleration data representative of patient position with respect to rotational axes of the patient, and determining in a processor orientation of the patient using the corrected acceleration data.

13 . The method of claim 12 wherein the at least one correction factor is based on patient-specific data.

14 . The method of claim 12 wherein the at least one correction factor is predetermined.

15 . A method for calibrating the acceleration data output by a sensor that is wearable by a patient for monitoring patient movement and position comprising: providing to a processor a predetermined correction factor as an offset for an angle of the sensor relative to the rotational axis of a patient, providing to a processor data representative of acceleration measured by the sensor, applying, in the processor, the correction factor to the data representative of sensor acceleration in a rotation matrix, outputting corrected acceleration data representative of patient position with respect to the rotational axis of the patient, and determining in a processor orientation of the patient using the corrected acceleration data.

Assignees

• Leaf Healthcare Inc

Inventors

• Larson Barrett J
• Shen Daniel Z
• Weckwerth Mark V
• HAMMOND Charles Matthew Peterson

Classifications

• G01P15/18

  in two or more dimensions · CPC title

• G16H40/67

  for remote operation · CPC title

• G16H20/00

  ICT specially adapted for therapies or health-improving plans, e.g. for handling prescriptions, for steering therapy or for monitoring patient compliance · CPC title

• A61B5/1116

  Determining posture transitions · CPC title

• G16H20/40

  relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture · CPC title