Skin patches for sensing or affecting a body parameter
View Patent ↗Skin patch sensors for monitoring and/or affecting body parameters, with alignment, positioning and attachment using magnets. The repeated use of releasable adhesive layers to retain skin patch sensors on skin can cause skin irritation, which can be reduced by rotating a skin patch between attachment times around a magnetically coupled pivot point. Skin patch sensors can be configured with internal coils to inductively couple to external power transmitting and communications coils with solenoids in anti-Helmholtz configurations.
1. A skin patch being:
for releasable attachment to a skin location of a patient,
the skin patch comprising:
a housing comprising a base for supracutaneous attachment to the skin location and a cover covering the base;
at least one ferromagnetic element for subcutaneous implantation below the skin location;
at least one magnet to position the skin patch at the skin location by magnetic coupling with the at least one ferromagnetic element, the at least one magnet being in the housing and affixed to the base and defining an aperture therewithin;
at least one electrode for sensing a body parameter and/or for affecting a body parameter, the at least one electrode being on the base and located in the aperture of the at least one magnet;
an antenna coupled to the at least one electrode and to receive wireless power transmissions for powering the skin patch;
additional magnets at opposing ends along a longitudinal axis of the housing, adjacent to the at least one magnet, and to align the skin patch to the skin location, the additional magnets being strip shaped in a direction crossing the longitudinal axis of the housing;
additional ferromagnetic elements for subcutaneous implantation below the skin location and to position the skin patch at the skin location by magnetic coupling with the additional magnets, the additional ferromagnetic elements being strip shaped to correspond to the additional magnets,
wherein the antenna comprises a radio frequency (RF) coil.
2. The skin patch of claim 1 , wherein the radio frequency (RF) coil is a spiral coil.
3. The skin patch of claim 1 , further comprising a substrate or releasably attaching the skin patch to the skin location, the substrate having first and second opposite facing surfaces, and the substrate comprises:
an adhesive coating on a first layer of the substrate for releasable attachment to the skin patch; and
an adhesive coating on a second layer of the substrate for releasable attachment to the skin location.
4. The skin patch of claim 1 , wherein the at least one ferromagnetic element is a pivot point for rotation of the skin patch.
5. A system for controlling a prosthetic limb or an exoskeleton comprising:
the skin patch according to claim 1 , wherein the at least one electrode comprises a plurality of electrodes for sensing electromyographic (EMG) signals in a residual limb or a limb coupled to the exoskeleton, wherein the plurality of electrodes is coupled to a transmitter, and the transmitter is configured to transmit a data signal corresponding to sensed EMG signals via the antenna;
optionally at least one of the plurality of electrodes comprises at least one of: a needle electrode or a silicon electrode; and
a controller configured for coupling to the residual limb or to the limb coupled to the exoskeleton, the exoskeleton comprising:
an antenna for receiving the data signal from the skin patch, the antenna to transmit wireless power to the skin patch;
a receiver coupled to the antenna for processing the received data signal;
a transmitter coupled to the antenna for communications with the skin patch; and
the controller coupled to the receiver for generating a plurality of motion control commands for the prosthetic limb or the exoskeleton,
wherein the prosthetic limb or the exoskeleton is coupled to the controller and configured to receive and respond to the motion control commands.
6. The system of claim 5 , wherein the antenna of the controller comprises a plurality of solenoids in an anti-Helmholtz configuration for inductively coupling alternating current to the skin patch.
7. A skin patch being:
for multiple releasable attachments to a skin location of a patient,
the skin patch comprising:
a housing comprising a base for supracutaneous attachment to the skin location and a cover covering the base;
at least one ferromagnetic element for subcutaneous implantation below the skin location;
at least one magnet for positioning the skin patch at the skin location by magnetic coupling with the at least one ferromagnetic element, the at least one magnet being in the housing and affixed to the base and defining an aperture therewithin;
at least one electrode for sensing a body parameter and/or for affecting a body parameter, the at least one electrode being on the base and located in the aperture of the at least one magnet;
an antenna coupled to the at least one electrode for providing at least one of the following:
transmitting a wireless data signal corresponding to the sensed body parameter; and/or
receiving commands from an external controller;
a power supply for powering the skin patch;
additional magnets at opposing ends along a longitudinal axis of the housing, adjacent to the at least one magnet, and to align the skin patch to the skin location, the additional magnets being strip shaped in a direction crossing the longitudinal axis of the housing; and
additional ferromagnetic elements for subcutaneous implantation below the skin location and to position the skin patch at the skin location by magnetic coupling with the additional magnets, the additional ferromagnetic elements being strip shaped to correspond to the additional magnets.
8. The skin patch of claim 7 , wherein the magnetic coupling between the at least one magnet and the at least one ferromagnetic element releasably attach the skin patch to the skin location.
9. The skin patch of claim 7 , wherein the magnetic coupling between the at least one magnet and the at least one ferromagnetic element provide a pivot point for rotating the skin patch prior to a subsequent releasable attachment of the skin patch to the skin location.
10. The skin patch of claim 7 , wherein the power supply of the skin patch consists of either: a primary battery or a rechargeable battery.
11. The skin patch of claim 7 , wherein the antenna is configured to receive wireless power, and comprises at least one of:
a spiral coil,
a solenoid,
a spiral coil configured to inductively couple to a plurality of solenoids in an anti-Helmholtz configuration or
a solenoid configured to inductively couple to a plurality of solenoids in an anti-Helmholtz configuration.
12. The skin patch of claim 1 , wherein the at least one magnet is inside the skin patch.