Self-piercing pulse oximeter sensor assembly

A self-piercing pulse oximeter sensor is provided for attachment to subject, e.g., an individual or an animal. The device includes a flexible pulse oximeter sensor, an earring post, and a grommet. The earring post may be used as a piercing device if there is not a pierced body part suitable for attaching the pulse oximeter sensor to the body. Otherwise the earring post may be slid into the pierced hole. In either case, the tip of the earring post engages a grommet once passing through the body part. Thus, the pulse oximeter sensor functions in a transilluminance mode by transmitting light through the pierced body part.

I. FIELD OF THE INVENTION 
The invention relates to transillumination pulse oximetry. More 
particularly, the invention is directed to a self-piercing pulse oximeter 
sensor capable of attachment to either an individual or an animal through 
a pierced body part. 
II. BACKGROUND OF THE INVENTION 
Prior pulse oximeter sensors have been attached to an appendage of an 
individual such as a patient. A flexible pulse oximeter sensor is usually 
placed on a finger or toe of a patient who is in need of medical 
monitoring, with tape or a plastic clamp. The pulse oximeter sensor may 
also be taped to the ear or held in place on the ear with a plastic clamp. 
Attaching the pulse oximeter sensor to the ear usually occurs in a case 
where the patient is missing his/her digits, e.g., an amputee, or severely 
injured, or in the case of significant burns covering the body such that 
the placement of the pulse oximeter sensor on a peripheral body part is 
very difficult. However, monitoring via the ear is presently tenuous at 
best, as the methods of securing a pulse oximeter sensor to the ear are 
haphazard and unreliable. 
Furthermore, there are times when a patient will need to move while having 
a pulse oximeter sensor attached. An example of this is when a wounded 
soldier needs to remain in battle gear with his/her hands free to fight 
and/or operate equipment while being monitored. Other examples are 
laboratory testing or monitoring of the physiological status of an 
individual or moving a patient under field conditions as in battle or EMS 
activities. The present pulse oximeter sensors are attached in such away 
as to prevent this freedom of activity and movement. 
Notwithstanding the usefulness of the above-described pulse oximeter 
sensors, a need still exists for placement of a pulse oximeter sensor so 
that it will be secure with little risk of coming off of patients who have 
no sites for secure placement in the traditional fashion. Furthermore, a 
pulse oximeter sensor is needed that is capable of attachment to an 
individual who needs to have his/her extremities free of monitoring 
devices. 
III. SUMMARY OF THE INVENTION 
This invention solves the ongoing problems of attaching a pulse oximeter 
sensor to a patient who needs freedom of movement and/or lacks suitable 
sites for attachment. The invention while addressing the problems of the 
prior art obtains advantages that were not achievable with the prior art 
devices. 
In accordance with one aspect of the invention, a pulse oximeter sensor is 
provided which is attachable to pierced body parts, like pierced ear 
lobes. The invention may also be attached through a new piercing from its 
non-reactive puncture post. 
An object of this invention is to provide a stronger more fixed attachment 
of a pulse oximeter sensor to an individual. 
A further object of this invention is to provide flexibility in terms of 
where a pulse oximeter sensor is attached to an individual based on 
available body parts for attachment. 
Still another object of this invention is to attach a pulse oximeter sensor 
to an individual while allowing optimal freedom of movement for the 
individual. 
An advantage obtained by this invention is enhanced physical stability 
between the pulse oximeter sensor and the individual making it possible 
for better quality recordings of data signals and thereby better patient 
care. 
Another advantage obtained by the invention is that it provides a more 
reliable mechanism for taking oximetry measurements on animals. 
In accordance with an aspect of the invention, a pulse oximeter assembly is 
provided. The pulse oximeter assembly includes a pulse oximeter sensor 
including a flexible base and an aperture passing therethrough. A post 
provided with a sharp point may be connected to the pulse oximeter sensor. 
The point of the post should be sharp enough to pierce the flesh of a 
subject. A grommet is disposed on the flexible base to frame the aperture. 
In accordance with another aspect of the invention, a pulse oximeter 
assembly is provided. The pulse oximeter assembly includes a flexible 
pulse oximeter sensor which comprises a flexible base, a hole passing 
through the flexible base, a light source disposed on the flexible base, a 
light detector disposed on the flexible base, and a connector coupled to 
the light source and the light detector. A post having a shaft extending 
through the flexible base is provided to facilitate attachment of the 
pulse oximeter assembly to a subject's desired body part. A grommet is 
disposed on the flexible base, such that the grommet frames the hole 
passing through the flexible base.

V. DETAILED DESCRIPTION OF THE INVENTION 
FIGS. 1-3 illustrate a preferred embodiment of the self-piercing pulse 
oximeter sensor assembly 10. The self-piercing pulse oximeter assembly 10 
includes a grommet 12, an earring post 14, a light source 20, and a light 
detector 22; each of these is connected to a flexible base 26. More 
particularly, the light source 20 and the light detector 22 may be 
disposed on an outer surface of the flexible base 26 or disposed within 
the flexible base 26. A connector 24 may be coupled to flexible base 26 
through cabling 28. The term earring post is used simply as a convenience 
to describe a piercing structure. However, this structure is not limited 
to connection to an ear lobe, but the device may be attached to a variety 
of body parts of a subject such as a person or an animal. 
Examples of the flexible pulse oximeter suitable for this invention are 
shown in U.S. Pat. Nos. 4,621,643 and 4,700,708 and embodied by the 
Nellcor.RTM. Oxysensor.RTM. II D-25. The light source 20 preferably is one 
or more of the following: a light emitter, a bispctral emitter, a dual 
spectral emitter, a photoemitter, two light emitting diodes (LED), a 
photodiode, or a semiconductor die. However, any light source that 
facilitates reflectance pulse oximetry may be employed. When the light 
source 20 is one light emitter then the light emitter, for example, would 
emit two frequencies of light at about 660 nm and about 940 nm. Typically, 
a two emitter arrangement will include a red LED near 660 nm and a 
near-infrared LED emitting in the range of 890 to 950 nm. The light source 
20 may emit light having a bandwidth in the range of 20 to 50 nm. 
The light detector 22 detects light emitted by light source 20. Electrical 
signals representing the detected light through the connector 24 to a 
spectrophotometer or pulses oximeter that discriminates between the 
relative intensity of these emissions and provides an index as to the 
degree of oxygen saturation of hemoglobin in blood. The light detector 22 
may be one of the following devices: a photoelectric receiver, a 
photodetector, a photodiode, or a semiconductor die. 
The connector 24 preferably includes contact electrodes, conductive lines 
and a cord. The light source 20 and the light detector 22 are each 
connected to a respective contact electrode. The conductive lines connect 
the contact electrodes to the cord. The cord connects to a 
spectrophotometer. 
In keeping with the invention, the flexible pulse oximeter sensor may be 
attached to the earring post 14. The earring post 14 may be threaded 
through a subject's ear lobe thus facilitating attachment of the pulse 
oximeter assembly 10 to a subject's ear as illustrated in FIG. 3. The 
earring post 14 is preferably manufactured from non-physiologically 
reactive materials such as metal or plastic. The earring post 14 may be 
mounted on a flat thin base 15 that stabilizes the earring post 14 
preferably at right angles with respect to the flexible pulse oximeter 
sensor. The base 15 may be incorporated within the flexible base 26. 
Preferably, the flat base 15 is also made of non-physiologically reactive 
materials. 
The earring post 14 may be capable of piercing a body part 30 of the 
subject if a pre-pierced body part is not available or is deemed 
insufficient for engagement. The earring post 14 preferably has a sharp 
tip that provides the piercing capability. In accordance with a preferred 
aspect of the invention, the earring post 14 may be sufficiently sharp to 
pierce an ear lobe, the webbing between fingers or toes, the foreskin, the 
tongue, the nose, eyebrows, breast nipples, the cheek/lip, etc. One of 
ordinary skill in the art will realize that other parts of the body beyond 
those listed could be pierced sufficiently to allow for transillumination 
pulse oximetry. If the webbing is chosen for piercing, then preferably the 
webbing between the thumb and the forefinger on one hand is pierced. 
Furthermore, if piercing of a body part is not required, then the earring 
post 14 may readily slide through the previously pierced hole. 
The grommet 12 reinforces a hole or eyelet made in and through the flexible 
pulse oximeter sensor. The grommet 12 engages and holds the tip of the 
earring post 14 after the earring post 14 is placed through and in the 
selected body part of the subject being monitored. The grommet 12 and the 
earring post 14 preferably are at or near opposite ends of flexible base 
26. 
After the pulse oximeter sensor is no longer needed for monitoring, the 
grommet 12 may be disengaged from the earring post 14 and the earring post 
14 may be removed from the body part. As a result, the self-piercing pulse 
oximeter may be worn, put on, and/or removed in a manner similar to an 
earring that a person might wear for decoration. 
To strengthen the connection between the grommet 12 and the earring post 
14, an earring-securing piece 16 may be attached to the earring post 14 
after it passes through the grommet 12 as shown in FIG. 3. Preferably, the 
earring-securing piece 16 may be made of either plastic or nonreactive 
metal. A suitable earring-securing piece 16 may be a standard 
earring-securing piece that is typically found on off-the-shelf pierced 
earrings. The earring-securing piece 16 may also be incorporated into the 
grommet 12 as a single securing device. 
Another embodiment of the invention is illustrated in FIG. 4. The pulse 
oximeter sensor includes an earring post 14, a flexible pulse oximeter 50, 
and an earring-securing piece 16. The flexible pulse oximeter 50 includes 
a light source 20, a light detector 22, and a connector 24. 
The flexible pulse oximeter 50 may be wrapped around the body part through 
which the transillumination is to occur such that when attached the 
earring post 14 passes through the two ends of the flexible pulse oximeter 
50 and the body part. In this embodiment, the earring post 14 is then 
either pierced through the flexible pulse oximeter 50 and the body part or 
simply pressed through the flexible pulse oximeter 50 into a previously 
pierced body part. The earring-securing piece 16 is attached to the 
earring post 14 to attach the flexible pulse oximeter 50 to the body part 
and thus the individual. 
This invention may be used in patient populations where monitoring is 
difficult such as field injury or illness, severely burned patients, 
multiple amputees or astronauts/pilots/soldiers/workers who need 
extremities free to perform certain activities like fighting or 
controlling/operating a vehicle or machinery. This invention may also be 
used to monitor healthy persons while they work, fight, or perform other 
activities for health status surveillance. This invention may also find 
uses in the veterinary sciences for monitoring oxygen levels in animals, 
which monitoring would encounter similar problems as that with monitoring 
humans. 
The preferred uses allow the pulse oximeter assembly to be firmly attached 
to the subject without fear of it becoming dislodged during transport 
and/or movement by the subject wearing the pulse oximeter sensor. The 
versatility in attaching the pulse oximeter assembly will allow its use by 
special operations soldiers, pilots, astronauts, divers and other similar 
professionals while they carry out their duties to allow monitoring of the 
local tissue oxygen saturation. 
Those skilled in the art will appreciate that various adaptations and 
modifications of the above-described preferred embodiments can be 
configured without departing from the scope and spirit of the invention. 
Therefore, it is to be understood that, within the scope of the appended 
claims, the invention may be practiced other than as specifically 
described herein.