Sensors for monitoring movements, apparatus and systems therefor, and methods for manufacture and use

A sensor comprising a hollow elongated tubular coil unit including input excitation and output pick up windings wound about essentially the same portion of the sensor longitudinal axis and an elongated magnetic core having cross sectional dimensions substantially less than the inside dimensions of the coil unit adapted to extend within the coil unit for approximately the same positioning relative to both the excitation and pick up windings, the core and coil exhibiting a loose mechanical coupling there between wherein coil unit and core are free to move relative to each other along the axis.

A method of making an electrical inductive sensor comprising the steps of:

• providing a hollow elongated tubular shaped bobbin;
• winding a coil, having an excitation winding and a pick up winding, concentrically about approximately a common portion of the bobbin and providing flexible connections extending from the windings, and
• inserting an elongated magnetic rod having cross sectional dimensions less than the inner dimensions of the bobbin into the coil so that the rod fits loosely within the bobbin and is free to move longitudinally within the coil while keeping approximately the same positioning relative to both the excitation and pick up windings.

A sensor for monitoring bodily functions comprising at least one sensor having attachment units adapted to be attached to external body skin at two separate locations for providing indications of skin deformation between the two locations, wherein the sensor comprises a coil having an input excitation winding and an output pick up winding and a magnetic core positioned within the coil by a loose mechanical coupling, wherein the core and coil are movable with respect to each other in a generally linear direction to follow deformations of the skin to provide indications in the form of sensor inductive reactance changes as function of the skin deformations and wherein the mass of the sensor and the loose mechanical coupling between the coil and core are such as to insignificantly interfere with the deformation of the skin to be attached between the attachments.

A sensor comprising:

• two coil units, each comprising a hollow tube having an elongated axis and each coil unit includes input excitation and output pick up windings wound about approximately the same portion of the tube, and the coil units being positioned adjacent to each other end to end along their axis;
• two elongated magnetic cores, each positioned within the tube of separate coil units from opposite ends with a loose mechanical coupling wherein the cores and coil units are free to move relative to each other along the elongated axis, and to rotate about the axis, and
• an attachment unit extending from each of the cores.

A sensor for monitoring movements comprising two coils in the form of an elongated hollow cylinder having a longitudinal axis, and each coil unit having input excitation and output pick up windings wound concentrically along approximately the same portion of the coil cylinder, and a common elongated magnetic core adapted to be inserted into both coil units in a loose mechanical coupling for free movement therein, an attachment unit for the coil units and an attachment unit for the core.

A sensor for receiving electrical pulses from a capacitive signal source for monitoring movements of objects, the sensor comprising at least one coil having an excitation winding adapted to be connected to the signal source and a pick up winding, a core for positioning within the coil, the coil and core being adapted to be attached to the object to be monitored, the pick up winding adapted to provide output signals in response to pulses applied to the excitation winding that are a function of the relative positioning between the coil and core at the time the pulse is applied to the excitation winding, which output signal is in the form of a decaying signal that includes a polarity change.

A sensor for monitoring the deformation of flexible membrane comprising at least one coil having an excitation winding and at least one pick up winding wound in a form of an elongated hollow cylinder and adapted to be attached to a the membrane, and an elongated magnetic core adapted to be inserted into the coil in a loose coupling for free movement therein and adapted to be attached to a different portion of the membrane surface, wherein the inductance of the sensor as sensed by the pick up winding varies as a function of the relative positioning of the core and the coil as the membrane there between deforms, wherein the mass of the coil and core and the free relative movement of the core and the coil being such that the coils and the core move to follow the deformation of the membrane with insignificant interference with the deformation movements of the membrane.

A sensor for monitoring bodily functions comprising at least one sensor adapted to be attached to external body skin at two separate locations for providing indications of skin deformation between the two locations wherein the sensor comprises two parts movable with respect to each other in a generally linear direction to follow deformations of the skin and to provides indications in the form of sensor inductive reactance changes as function of the skin deformations and wherein the mass of the sensor and the free movement between the two parts is such as to insignificantly interfere with the deformation of the skin between the two locations.

A sensor circuit adapted to receive electrical pulses from a capacitive source for monitoring movements of an object comprising:

• at least one coil including an input winding and an output winding;
• a magnetic core extending into the coil, and
• a circuit adapted for connecting the capacitive source to the input winding for applying pulses thereto by discharging through the input winding.

A bandage type sensor for attachment to a flexible membrane for providing indications of deformations of the membrane comprising:

• an electrical sensor including two components movable relative to each other to provide indications of displacements there between;
• a first bandage layer partially encasing the sensor and provisionally capturing the two sensor components, and
• a second layer attached to the bottom of the first layer and readily detachable there from whereby the bandage type sensor is adapted to be attached to a flexible membrane with the sensor released from the first layer.

A method of making a bandage type electrical inductive sensor comprising the steps of:

• providing a sensor including two components movable relative to each other to provide indications of displacements there;
• providing a first bandage layer to partially encase the sensor, and
• attaching a second layer to the bottom of the first layer that is readily detachable there from so that the sensor can be exposed for attachment to a flexible membrane by the first layer.

Apparatus for monitoring movements comprising:

• a sensor comprising a coil having an input winding and an output winding and a magnetic core extending into the coil for generally linear relative movement there between wherein the inductance of the sensor changes as a function of the relative displacement between the core and the coil, and
• a monitoring circuit coupled to the sensor input and output circuits including a circuit for applying pulses to the input circuit, wherein the output circuit provides a decaying signal response for each pulse applied to the input circuit, the rate of decay of the signal being a function of the relative displacement between the coil and core, and the monitoring circuit is responsive to the rate of decay of the sensor output signals for providing indications of the relative displacements between the coil and core.

Apparatus for monitoring movements comprising:

• an electrical sensor comprising two components wherein one component is adapted to positioned within the other for relative movement there between, and including an input circuit for receiving excitation signals and an output circuit for providing output signals, and
• a monitoring circuit coupled to the input and output circuits, including a generator circuit for applying electrical pulses to the input circuit wherein the output circuit provides a decaying signal response for each pulse applied to the input circuit having a decay rate that is a function of the relative displacement between the two sensor components, the monitoring circuit being responsive to the output signal decay rate for providing indications of the relative displacements between the two sensor components, and wherein the monitoring circuit processes a selected range of signals, and includes a control circuit for modifying the monitoring circuit operating parameters to adapt the monitoring circuit to the scope of sensor displacements.

A method for monitoring movement for use with a sensor that includes at least two movable parts adapted to be attached to separate parts of an object, and wherein the inductance of the sensor varies as a function of the disposition of the two parts relative to each other, the method comprising the steps of:

• applying time separated electrical pulses to the sensor, and
• analyzing the response of decaying signals from the sensor, the duration of which is a function of the inductance of the sensor to provide an indication of changes in the disposition of the movable parts.

A method of monitoring the expansion and contraction of a flexible membrane comprising the steps of:

• sensing the expansion and contraction between portions of the membrane in a manner so as to insignificantly interfere with the movements by the membrane there between to produce output electrical signals that are a function of the expansion and contraction between the portions of the membrane, and
• processing the outputs signal to provide an indication of the expansion and contraction.

Apparatus for use in monitoring internal physiological changes of a body based upon deformations of body skin comprising a sensor including a coil having an input winding and an output winding and a magnetic core extending into the coil, wherein changes in inductive reactance are exhibited by the sensor output winding that are a function of the relative dispositions between the core into the coil, the coil and core being adapted to be attached to body skin at separate points, and a monitoring circuit for applying electrical pulses to the input winding, the monitoring circuit being responsive to the output signals for providing indications of the deformations of the skin.

A method for monitoring body skin expansions and contractions comprising the steps of non-intrusively physically sensing, in the form of electrical impedance changes, the expansions and contractions between two points on external surface of body skin in a manner so as not to introduce significant interference with the skin expansions and contractions, and converting the changes of impedances into electrical signals that are a function of the skin expansions and contractions.

A method of non-intrusively monitoring bodily functions comprising:

• providing a sensor including a coil and a magnetic core extending within the coil;
• attaching the coil and core to external body skin for providing indications of skin deformations with insignificant interference with the skin deformations, and
• converting the indications of skin deformations into displays thereof.

A sensor system for monitoring the displacement between movable parts of an object comprising:

• an electrical sensor comprising two components, one component being adapted to be positioned within the other for generally linear movement there between, and having input and output circuits, wherein the electrical impedance of the sensor changes as a function of the relative displacement between the components, the components of the sensor being adapted to be attached to different movable parts of the object for providing impedance changes corresponding to displacements;
• a circuit for applying pulses to the input circuit wherein the output winding outputs decaying signals, the rate of decay being a function of the relative displacement between the components, and
• a monitoring circuit is responsive to the output signal decay rate for providing indications of the displacements between the movable parts of the object.

Monitoring apparatus for use with a sensor that includes at least two movable parts adapted to be attached to separate parts of an object, and wherein the electrical impedance of the sensor varies as a function of the disposition of the two parts relative to each other, the apparatus comprising:

• a circuit for applying time separated electrical pulses to the sensor, and
• a circuit for analyzing the response of the sensor to the electrical pulses in the form of a decaying signals, the duration of which is a function of the impedance of the sensor, to provide an indication of changes in the disposition between the movable parts.

Circuit apparatus for use with a sensor that includes at least two movable parts adapted to be attached to separate movable parts of an object, and wherein the electrical impedance of the sensor varies as a function of the disposition of the two parts relative to each other, the apparatus comprising:

• a monitoring circuit responsive to changes in sensor impedance to provide signals the magnitude of which is a function of the impedance exhibited by the sensor;
• a processing circuit coupled to receive the signals to provide an output signals indicative of the displacement of the parts, and
• a control circuit for controlling the operating parameters of the monitoring circuit to conform its operation with the scope of impedance changes exhibited by the sensor.

A power savings method of operating sensing apparatus including a sensor and a monitoring circuit for analyzing the output of the sensor comprising the steps of:

• initiating a test cycle of the sensing apparatus by applying a first timer circuit output pulse to the sensor;
• enabling a second timer circuit to apply timing pulses to the monitoring circuit at a rate that is substantially greater than the first timer pulse rate so that the monitoring circuit is enabled to process the output from the sensor at a time substantially shorter than the first timer pulse rate, and
• disabling the second timer from applying pulses to the monitoring circuit until a subsequent test cycle is initiated.