Patient movement sensor
A motion sensor for detecting the movement of a patient is provided and includes a housing, a spring loaded return mechanism supported in the housing, an encoder, and a sensor. The spring loaded return mechanism includes a spool rotatably supported within the housing, a biasing member coupled to the housing and the spool, and a cord supported on the spool. The encoder is located on the spool and is configured to monitor a length of cord extended from the housing. The sensor is configured to communicate a signal when the cord is extended beyond a predetermined or preset length.
1. A motion sensor for detecting the movement of a patient, the motion sensor comprising:
a housing having a first attachment portion;
a spring loaded return mechanism supported in the housing, the spring loaded return mechanism including:
a spool rotatably supported within the housing;
a biasing member coupled to the housing and the spool; and
a cord supported on the spool, the cord having a first end and a second end, the first end of the cord coupled to the spool and the second end of the cord having a second attachment portion including a patient-engaging element, wherein the second end of the cord is extendable such that the spool is rotated about the housing;
an encoder located on the spool, the encoder configured to monitor a length of cord extended from the housing;
a sensor configured to communicate a signal when the cord is extended beyond a predetermined or preset length; and
a gyroscope disposed in mechanical cooperation with the encoder and configured to measure an angle of a longitudinal axis of a patient relative to a preset longitudinal axis.
2. The motion sensor according to claim 1 , wherein the first attachment portion of the housing of the motion sensor is configured to be attached to a surgical table and the second attachment portion of the cord of the motion sensor is configured to be attached to a patient.
3. The motion sensor according to claim 1 , wherein the encoder is located coaxially around the spool.
4. The motion sensor according to claim 1 , wherein the encoder is configured to convert an angular position of the spool into a distance traveled by the cord.
5. The motion sensor according to claim 2 , wherein the encoder is configured to calculate an initial distance traveled by a patient.
6. The motion sensor according to claim 1 , wherein the patient-engaging element includes a wrist band.
7. The motion sensor according to claim 6 , wherein the wrist band includes a hook-and-loop portion.
8. The motion sensor according to claim 1 , wherein the patient-engaging element includes a snap on attachment portion.
9. The motion sensor according to claim 1 , wherein the patient-engaging element includes an adhesive pad.
10. A motion sensor for detecting the movement of a patient, the motion sensor comprising:
a housing having a first attachment portion;
a spring loaded return mechanism supported in the housing, the spring loaded return mechanism including:
a spool rotatably supported within the housing;
a biasing member coupled to the housing and the spool; and
a cord supported on the spool, the cord having a first end and a second end, the first end of the cord coupled to the spool and the second end of the cord having a second attachment portion, wherein the second end of the cord is extendable such that the spool is rotated about the housing;
an encoder located on the spool, the encoder configured to monitor a length of cord extended from the housing;
a sensor configured to communicate a signal when the cord is extended beyond a predetermined or preset length; and
a gyroscope disposed in mechanical cooperation with the housing and configured to measure an angle of a longitudinal axis of a patient relative to a preset longitudinal axis.