Head worn apparatuses for vision therapy
Systems, devices, and methods for use in delivering stimulation to the head of a patient, including examples directed to delivering electrical or other stimulation to the eye of the patient. In some examples eyepieces or eyepatches are configured to deliver electrical or other stimulus to the eye of a patient by being worn on the face of the patient.
1 . A patient interface apparatus for delivery of stimulus to a portion of the head of a patient for a session, the patient interface apparatus comprising:
a first eyepiece adapted to fit about at least one eye of the patient;
wherein the first eyepiece comprises at least first and second electrodes, the first eyepiece further comprising at least first and second electrical connectors separately coupled to the first and second electrodes;
wherein the patient interface apparatus further comprises a pulse generator coupled to at least the first and second electrical connectors to issue electrical therapy pulses using the first and second electrodes; and
wherein the pulse generator is configured to:
monitor a tissue impedance between the first and second electrodes before commencement of the electrical therapy to establish an initial impedance-based threshold for the patient;
define a session-specific acceptable impedance upper limit on the basis of the initial threshold;
compare a subsequently monitored tissue impedance to the session-specific acceptable impedance upper limit; and
interrupt or withhold the electrical therapy when the subsequently monitored tissue impedance exceeds the session-specific acceptable impedance upper limit.
2 . The patient interface apparatus of claim 1 , further comprising a frame or a strap to hold the first eyepiece on the head of the patient, wherein the first eyepiece is configured to hold the first electrode on the patient's eyelid.
3 . The patient interface apparatus of claim 1 wherein the first eyepiece is a closed eyepiece having a transparent portion through which the patient can see while wearing the first eyepiece.
4 . The patient interface apparatus of claim 1 , wherein the pulse generator is configured to issue therapy pulses by using the first and second electrodes of the first eyepiece as opposing electrodes.
5 . The patient interface apparatus of claim 4 , wherein the first and second electrodes are positioned on the eyepiece above and below the transparent portion.
6 . The patient interface apparatus of claim 4 , wherein the first and second electrodes are positioned on the eyepiece below the transparent portion.
7 . The patient interface apparatus of claim 4 , wherein the pulse generator is configured to issue the therapy pulses using the first and second electrodes of the first eyepiece as opposing electrodes without a separate return electrode.
8 . The patient interface apparatus of claim 1 , further comprising a second eyepiece adapted to fit about at least one eye of the patient and including at least third and fourth electrodes, the second eyepiece further comprising at least third and fourth electrical connectors separately coupled to the third and fourth electrodes, wherein the pulse generator is coupled to the third and fourth electrical connectors to issue therapy pulses from the third and fourth electrodes.
9 . The patient interface apparatus of claim 8 , wherein the pulse generator is configured to issue therapy pulses using the first and second electrodes together as one of anode or cathode, and using the third and fourth electrodes together in electrical opposition to the first and second electrodes.
10 . A method of treating a patient having a vision disorder comprising:
having the patient wear a patient interface apparatus for a session comprising:
(i) a first eyepiece adapted to fit about at least one eye of the patient, wherein the first eyepiece comprises at least first and second electrodes, the first eyepiece further comprising at least first and second electrical connectors separately coupled to the first and second electrodes, and
(ii) a pulse generator coupled to at least the first and second electrical connectors to issue therapy pulses using the first and second electrodes; and
activating the pulse generator to issue an electrical therapy to the eye using the first and second electrodes as a series of electrical therapy pulses;
monitoring a tissue impedance between the first and second electrodes before commencement of the electrical therapy to establish an initial impedance-based threshold for the patient;
defining a session-specific acceptable impedance upper limit on the basis of the initial threshold;
comparing a subsequently monitored tissue impedance to the session-specific acceptable impedance upper limit; and
interrupting or withholding the electrical therapy when the subsequently monitored tissue impedance exceeds the session-specific acceptable impedance upper limit.
11 . The method of claim 10 , wherein the patient interface apparatus further comprises a frame or a strap to hold the first eyepiece on the head of the patient, and wherein the first eyepiece is a closed eyepiece having a transparent portion through which the patient can see while wearing the first eyepiece and receiving electrical therapy.
12 . The method of claim 10 , wherein the step the pulse generator issuing the electrical therapy comprises the pulse generator using the first and second electrodes of the first eyepiece as opposing electrodes.
13 . The method of claim 12 , wherein the first and second electrodes are positioned above and below the eye.
14 . The method of claim 12 , wherein the first and second electrodes are positioned below the eye.
15 . The method of claim 12 , wherein the pulse generator using the first and second electrodes of the first eyepiece as opposing electrodes is performed without the use of a separate return electrode.
16 . The method of claim 10 , wherein the patient interface apparatus includes a second eyepiece adapted to fit about at least one eye of the patient and including at least third and fourth electrodes, the second eyepiece further comprising at least third and fourth electrical connectors separately coupled to the third and fourth electrodes, wherein the pulse generator is coupled to the third and fourth electrical connectors to issue therapy pulses from the third and fourth electrodes.
17 . The method of claim 16 , wherein the step of the pulse generator issuing the electrical therapy as a series of electrical therapy pulses comprises using the first and second electrodes together as one of anode or cathode, and using one or more return electrodes in electrical opposition to the first and second electrodes.
18 . The patient interface apparatus of claim 1 , further comprising one or more return electrodes.
19 . The patient interface apparatus of claim 18 , wherein the one or more return electrodes are coupled to an earpiece of the frame.
20 . The patient interface apparatus of claim 18 , wherein the impedance of the at least one of the first and second electrodes is measured relative to the one or more return electrodes.
21 . The patient interface apparatus of claim 20 , wherein the pulse generator is further configured to determine tissue-electrode contact quality by selectively enabling one of the first and second electrodes while disabling the other, and measuring impedance between the enabled electrode and the one or more return electrodes.
22 . The patient interface apparatus of claim 20 , wherein the pulse generator is configured to perform differential impedance measurements by measuring impedance between each of the first and second electrodes and the one or more return electrodes, and comparing the measured impedances to one another to identify which electrode has inadequate tissue contact.
23 . The patient interface apparatus of claim 20 , wherein the pulse generator is configured to confirm tissue contact at the first and second electrodes by performing localized impedance tests between the first and second electrodes without referencing the one or more return electrodes, and using results of the localized impedance tests in conjunction with impedance measurements relative to the one or more return electrodes to distinguish whether high impedance is caused by one of the first and second electrodes or by the one or more return electrodes.
24 . The patient-interface apparatus of claim 20 , further comprising a third electrode, wherein the pulse generator is configured to deliver a diagnostic test stimulus between at least one of the first and second electrodes and the one or more return electrodes while sensing an electrical response at the third electrode to determine tissue-electrode contact quality prior to or during the electrical therapy.
25 . The patient-interface apparatus of claim 1 , wherein the pulse generator is configured to deliver a low-amplitude diagnostic pulse, distinct from the electrical therapy pulses, to obtain the initial tissue-impedance measurement and to refrain from issuing the electrical therapy pulses until the measured tissue impedance is below the session-specific acceptable impedance upper limit.
26 . The patient-interface apparatus of claim 1 , wherein the pulse generator is further configured to monitor the tissue impedance at predetermined intervals during the sequence of electrical therapy pulses, dynamically update the session-specific acceptable impedance upper limit in accordance with changes in the monitored impedance, and interrupt the electrical therapy when the monitored impedance falls outside the updated upper limit.
27 . The patient-interface apparatus of claim 1 , wherein the pulse generator is configured to: define a session-specific acceptable impedance range including the upper limit on the basis of the initial threshold; compare a subsequently monitored tissue impedance to the session-specific acceptable impedance range; and interrupt or withhold the electrical therapy when the subsequently monitored tissue impedance lies outside the session-specific acceptable impedance range.
28 . The patient-interface apparatus of claim 1 , wherein the pulse generator is further configured to determine if the initial threshold is within an acceptable range.
29 . The patient interface apparatus of claim 1 , wherein the pulse generator is configured to issue therapy pulses using the first and second electrodes together as one of anode or cathode, and using one or more return electrodes in electrical opposition to the first and second electrodes.